Visceral Manifold Study for the Repair of Thoracoabdominal Aortic Aneurysms
Phase: NA
Conditions: Thoracoabdominal Aortic Aneurysm
Sponsor: Vanderbilt University Medical Center

 
Clinical Protocol 
 
Visceral Manifold Study for the Repair of Thoracoabdominal Aortic Aneurysms 
 
Protocol Number: IP-01-001 
 
Device: Medtronic Valiant Thoracoabdominal (VTAAA) stent graft system 
 
IDE Approval Date: September 23, 2016 
IDE Number: G160182 
Protocol Version 5: July 30, 2020 
Protocol Version 4: June 18, 2020 
Protocol Version 3: May 2, 2018 
Protocol Version 2: August 22, 2017 
Protocol Version 1: September 27, 2016 
 
 
 
 

 
 
 
Page 2 of 103 
 
 
 
 
 
 
Title: Visceral Manifold Study for the Repair of Thoracoabdominal Aortic Aneurysms   
 
Protocol Number: IP-01-001 
Protocol Version 5: July 30, 2020 
I confirm that I have read this protocol. I will comply with the protocol and the 
principles of Good Clinical Practice (GCP), as described in the United States Code of 
Federal Regulation (CFR) 21 Parts 11, 50, 54, 56, and 812 and the appropriate 
International Conference on Harmonisation guidance documents. 
 
 
 
Signature 
 
 
 
Thomas C. Naslund M.D., Principal Investigator 
 
Date 
 
 
 
 

 
 
 
Page 3 of 103 
 
1. Table of Contents 
 
Contents 
1. Table of Contents ................................................................................................................................................. 3 
2. Protocol Synopsis ................................................................................................................................................. 5 
3. Report of Prior Investigations (§ 812.27) ........................................................................................................... 19 
3.1 Anatomy ....................................................................................................................................................... 19 
3.2 Pathophysiology ........................................................................................................................................... 19 
3.3 Treatment Options ....................................................................................................................................... 21 
3.4 Benefits and Risks of Treatment Options ..................................................................................................... 31 
3.5 Justification for Specific Patient Selection Criteria Relevant for this Study ................................................. 35 
3.6 Device Description and Drawings ................................................................................................................. 41 
4. Investigation Plan ............................................................................................................................................... 50 
4.1 Purpose ......................................................................................................................................................... 50 
4.2 Intended Use ................................................................................................................................................ 50 
4.3 Device Description ........................................................................................................................................ 51 
4.4 Protocol ........................................................................................................................................................ 52 
4.5 Risk Analysis ................................................................................................................................................. 79 
4.5.1 Potential Risks ........................................................................................................................................... 79 
4.5.1.1 Procedural-related risks ...................................................................................................................... 79 
4.5.1.2 Material-related risks .......................................................................................................................... 80 
4.5.1.3 Performance related risks ................................................................................................................... 80 
4.6 Data Management ........................................................................................................................................ 85 
4.7 Reporting ...................................................................................................................................................... 86 
4.8 Oversight ...................................................................................................................................................... 90 
4.9 Definitions .................................................................................................................................................... 91 
5. Manufacturing Information ................................................................................................................................ 97 
6. Investigator Agreement and Certification .......................................................................................................... 97 
7. IRB Information .................................................................................................................................................. 97 
8. Amount to be charged........................................................................................................................................ 97 

 
 
 
Page 4 of 103 
 
9. Labeling .............................................................................................................................................................. 98 
10. Medicare Generalizability ................................................................................................................................ 98 
11. References ........................................................................................................................................................ 99 
 
 
 

 
 
 
Page 5 of 103 
 
2. Protocol Synopsis 
Investigational Plan Synopsis 
Study Title 
 Visceral Manifold Study for the Repair of Thoracoabdominal Aortic 
Aneurysms.  
 
Investigational 
Devices 
Medtronic Valiant Thoracoabdominal (VTAAA) Stent Graft System  
Sponsor/Principal 
Investigator and Co-
Investigators 
Thomas C. Naslund, M.D. 
John A. Curci, M.D. 
Clifford L. Garrard III, M.D. 
Patrick A. Stone, M.D. 
Investigational Sites 
Vanderbilt University Medical Center  
 
The primary objective of the clinical investigation is to assess the use of 
the VTAAA stent graft system to repair thoracoabdominal aortic 
aneurysms in patients having appropriate anatomy. The primary intent of 

 
 
 
Page 6 of 103 
 
the study is to assess safety (i.e. freedom from major adverse events 
(MAE) at 30 days) and preliminary effectiveness (i.e., treatment success 
and technical success) of the device (i.e., the proportion of treatment 
group subjects that achieve and maintain treatment success at one year).   
Number of Subjects 
15 (8 patients to be enrolled in primary arm, 7 to be enrolled in expanded 
arm) 
Study Type and 
Duration 
Prospective, single center, nonrandomized, multiple arm study.  The 
duration of the Investigation is anticipated as follows: 
• Time to Complete Enrollment: 24 months 
• Subject Follow-up Time: 5 years from last subject enrollment 
• Total Duration Time: 7 years 
Intended  Use 
The VTAAA stent graft system is indicated for the endovascular 
treatment of thoracoabdominal aortic aneurysm (Crawford Type 1, 2, 3, 
and 5) in patients with the following characteristics: 
• An aneurysm with a maximum diameter of > 5.5 cm or 2 times 
the normal diameter just proximal to the aneurysm using 
orthogonal (i.e., perpendicular to the centerline) measurements 

 
 
 
Page 7 of 103 
 
• Aneurysm with a history of growth greater than or equal to 0.5 cm 
in 6 months 
• Saccular aneurysm deemed at significant risk for rupture 
• Symptomatic aneurysm greater than or equal to 4.5 cm 
• Axillary or brachial and iliac or femoral access vessel morphology 
that is compatible with vascular access techniques, devices or 
accessories, with or without use of a surgical conduit 
• Proximal landing zone for the thoracic bifurcation stent graft that 
has: 
o 
greater than or equal to 2.5 cm of nonaneurysmal 
aortic segment including previously placed graft 
material (neck) distal to the left subclavian artery 
(LSA) and diameter in the range of 26-42 
mmAdequate distance from the celiac artery, in order 
to accommodate cannulation from the antegrade access 
point when considering the total deployed length of the 
thoracic bifurcation and visceral manifold 
• 
Iliac artery or aortic distal fixation site, including both native 
tissue and previously placed graft, greater than or equal to 15 mm 
in length and diameter in the range of 8 – 25 mmAge: greater than 
or equal to 18 years old 
• Life expectancy: greater than 1 year 

 
 
 
Page 8 of 103 
 
Primary Arm 
Inclusion Criteria 
• A patient may be entered into the study if the patient has at least 
one of the following: 
o An aneurysm with a maximum diameter of greater than 
or equal to 5.5 cm or 2 times the normal diameter just 
proximal to the aneurysm using orthogonal (i.e., 
perpendicular to the centerline) measurements 
o Aneurysm with a history of growth greater than or equal 
to 0.5 cm in 6 months  
o Saccular aneurysm deemed at significant risk for rupture 
o Symptomatic aneurysm greater than or equal to  4.5 cm 
• Axillary or brachial and iliac or femoral access vessel morphology 
that is compatible with vascular access techniques, devices or 
accessories, with or without use of a surgical conduit 
• Proximal landing zone for the thoracic bifurcation stent graft that 
has: 
Greater than or equal to  2.5 cm of 
nonaneurysmal aortic segment including 
previously placed graft material (neck) distal to 
the left subclavian artery (LSA) and diameter 
in the range of 26-42 mm  
o Adequate distance from the celiac artery, in 
order to accommodate cannulation from the 

 
 
 
Page 9 of 103 
 
antegrade access point when considering the 
total deployed length of the thoracic bifurcation 
and visceral manifold 
• Iliac artery or aortic distal fixation site, including both native tissue 
and previously placed graft, greater than or equal to 15 mm in 
length and diameter in the range of 8 – 25 mm 
• Age:  greater than or equal to 18 years old 
• Life expectancy: greater than 1 year 
Primary Arm 
Exclusion Criteria 
• General exclusion 
• Patient is a good candidate for and elects for open surgical repair 
• Can be treated in accordance with the instructions for use with a 
legally marketed endovascular device 
• Is eligible for enrollment in a manufacturer-sponsored IDE at the 
investigational site 
• Unwilling to comply with the follow-up schedule 
• Inability or refusal to give informed consent  
• Urgent or emergent presentation 
• Patient is pregnant or breastfeeding 
• Patient has a contained rupture 
• Patient has a ruptured aneurysm 
• Patient has a dissection in the portion of the aorta intended to be 
treated 

 
 
 
Page 10 of 103 
 
• Obstructive stenting of any or all of the visceral vessels 
• Poor performance status including two major system failures 
(including but not limited to cardiovascular, pulmonary, renal, 
hepatobiliary, and neuromuscular)  Medical Exclusion Criteria 
• Known sensitivities or allergies to the materials of construction of 
the devices, including nitinol (Nickel: Titanium), polyester, 
platinum-iridium, polytetrafluoroethylene (PTFE), platinum, gold, 
polyethylene, or stainless steel.   
• Known hypersensitivity or contraindication to anticoagulation or 
contrast media that cannot be adequately medically managed  
• Uncorrectable coagulopathy 
• Body habitus that would inhibit x-ray visualization of the aorta or 
exceeds the safe capacity of the equipment 
• Patient has had a major surgical or interventional procedure 
unrelated to the treatment of the aneurysm planned less than 30 
days of the endovascular repair 
• Unstable angina (defined as angina with a progressive increase in 
symptoms, new onset at rest or nocturnal angina) 
• Systemic or local infection that may increase the risk of 
endovascular graft infection 
• Baseline creatinine greater than or equal to 2.0 mg/dL  

 
 
 
Page 11 of 103 
 
• History of connective tissue disorders (e.g., Marfan Syndrome in 
the primary arm only, not applicable for patients in the expanded 
access arm, Ehler’s Danlos Syndrome) 
• Prior aneurysm repair that would involve relining of the previously 
placed graft material requiring placement of the investigational 
system in a landing zone that expands beyond any limits of the 
previously placed graft material 
• Anatomical exclusion criteria 
• Minimum branch vessel diameter less than 5 mm 
• Thrombus or excessive calcification in the proximal aortic 
neckAnatomy that would not allow maintenance of at least one 
patent hypogastric artery  
• Anatomy that would not allow primary or assisted patency of the 
left subclavian artery 
Expanded Selection 
Arm Inclusion 
Criteria 
• Patient that meets the criteria for inclusion in the primary study 
arm but has one or more of the following criteria which would 
exclude them from the primary study arm: 
• Minimum branch vessel diameter less than 
5mm 
• Urgent or emergent presentation 
• Patient has a contained rupture 
• Patient has a ruptured aneurysm  

 
 
 
Page 12 of 103 
 
• Patient has a type B dissection (subacute or 
chronic) in the portion of the aorta intended to 
be treated 
• Poor performance status including two major 
system failures (including but not limited to 
cardiovascular, pulmonary, renal, 
hepatobiliary, and neuromuscular)   
• Baseline creatinine greater than or equal to 2.0 
mg/dL 
• Anatomy that does not allow for maintenance 
of at least one hypogastric artery 
• Anatomy that does not allow primary or 
assisted patency of the left subclavian artery 
• Prior aneurysm repair that would involve 
relining of the previously placed graft material 
requiring placement of the investigational 
system in a landing zone that expands beyond 
any limits of the previously placed graft 
material 
Obstructive stenting of any or all of the visceral 
vesselsOr 

 
 
 
Page 13 of 103 
 
• A patient that meets the criteria for inclusion 
into the primary study arm and: 
• Would not be eligible for the primary study 
arm per a documented reason other than those 
outlined above, and  
• Per the opinion of the Principal Investigator, 
with concurrence of the IRB, alternatives 
therapies are unsatisfactory and the probable 
risk of using the investigational device is no 
greater than the probable risk from the disease 
or condition.   
Primary Endpoint(s) 
The primary safety endpoint is freedom from major adverse 
events (MAE) at 30 days or during hospitalization if this exceeds 30 days.  
Major adverse events include death, bowel ischemia, myocardial 
infarction, paraplegia, renal failure, respiratory failure, and stroke. 
The primary effectiveness endpoint is the proportion of the study 
subjects with treatment success at 1 year.  Treatment success is defined as 
a composite of technical success and freedom from the following:  
o Aneurysm enlargement i.e., greater than or equal to 5 mm as 
compared to any previous CT measure using orthogonal (i.e., 
perpendicular to the centerline) measurements 

 
 
 
Page 14 of 103 
 
o Aneurysm rupture 
o Aneurysm-related mortality 
o Conversion to open repair  
o Secondary intervention for migration, Type I and III endoleaks, 
device integrity failure (e.g., fracture), and patency-related events 
(i.e., device component stenosis or occlusion and embolic events) 
Secondary Endpoints 
• Technical success and the individual components of 
technical success:  
o Successful delivery 
o Deployment at the intended implantation site 
o Patency of all endovascular graft and stent 
components 
o Absence of device deformations requiring 
unplanned placement of an additional device  
o Absence of inadvertent covering of aortic 
branch vessels 
o Successful withdrawal  
• Freedom from the individual components of the primary 
safety endpoint at 30 days: 
o Death 
o Bowel ischemia 
o Myocardial infarction 
o Paraplegia 

 
 
 
Page 15 of 103 
 
o Renal failure 
o Respiratory failure 
o Stroke 
• Freedom from paraparesis at 30 days 
• The following at each follow-up interval: 
o Treatment success and the individual 
components of treatment success including 
freedom from the following:  
- Aneurysm enlargement  
- Aneurysm-related mortality  
- Aneurysm rupture 
- Conversion to open repair 
- Secondary intervention for migration, 
type I and III endoleaks, device 
integrity failure (i.e., fracture), and 
patency-related events (i.e., device 
stenosis or occlusion and embolic 
events).  
- Renal failure 
- All-cause mortality 
- Endoleaks 
- Device integrity failure (e.g., fracture) 

 
 
 
Page 16 of 103 
 
- Patency-related events (i.e., device 
stenosis or occlusion and embolic 
events) 
- Other device-related events 
Follow-up Schedule 
Patients included in the study will undergo follow-up at one month, six 
months, twelve months and then annually for five years.   
Sample Size 
Justification 
The sample size for the feasibility study is limited to 15 (8 patients for the 
primary study arm and 7 patients for the expanded selection arm), as this 
is adequate to provide preliminary clinical safety data and effectiveness 
of the device.  The device, while novel, has been evaluated in a clinical 
setting and has initially demonstrated both safety and effectiveness.  The 
limited sample size allows adequate patient data to be collected under a 
controlled protocol without exposing a large patient population to the risk 
associated with a novel device design.  The safety and effectiveness data 
collected in this study will be pooled with other physician sponsored 
investigational device exemptions (PS-IDEs) evaluating the VTAAA 
stent graft system and should be sufficient to develop an appropriate 
pivotal study. 
Limitations to the 
Study 
Limitations of the study are that it is a single center study with a small 
patient population.  We aim to curb this limitation by pooling our data 
with other IDE holders.  

 
 
 
Page 17 of 103 
 
Study Monitor 
Routine data monitoring will occur to ensure data validity. Monitoring 
will occur at the following intervals: prior to the start of the clinical trial, 
at initiation of the study (at first implant and shortly thereafter with more 
frequent and intensive monitoring at the beginning of the study), at 
quarterly or interim periods, and at the end of the study.  Data monitoring 
will be conducted in person or via fax and telephone and will be tracked 
in the web-based data capture system by the Data Monitor.   
Study monitoring and auditing will be performed by experienced and 
appropriately trained personnel appointed by the sponsor/investigator to 
ensure that the investigation is conducted in accordance with FDA IDE 
regulations. 
Study Oversight 
A Data Safety Monitoring Board (DSMB) consisting of independent 
scientific and bio-statistical expertise, who are not participating as 
investigators in the study.  The DSMB will monitor and evaluate the 
safety of subjects and progress of the study. The board will meet after 
every 5th patient receiving the investigational device and annually during 
the follow-up period to review subject data.  During these meetings, the 
board will review participants in both study arms. The board will also 
meet at unscheduled times according to clinical necessity. The data safety 
reports reviewed at each meeting will contain enrollment data and all 
documented adverse events experienced by the participants and treatment 

 
 
 
Page 18 of 103 
 
 
outcomes.  The focus of the analysis is to determine whether enrollment 
should continue or be closed and whether the trials should continue as 
originally designed or require modification/amendment.    

 
 
 
Page 19 of 103 
 
3. Report of Prior Investigations (§ 812.27) 
3.1 Anatomy 
The aorta is the main artery that originates in the left heart chamber, ascends to the arch, and 
descends through the thoracic cavity and diaphragmatic muscle into the abdomen. The aorta gives a 
number of side branches throughout its trajectory from the mediastinum to the chest and abdomen. 
These branches include the coronary arteries, innominate artery, left common carotid artery, left 
subclavian artery, celiac axis (CA), superior mesenteric artery (SMA), renal arteries and inferior 
mesenteric artery (IMA) and various lumbar arteries. The aorta terminates at the aortic bifurcation 
where it divides into the common iliac arteries. Several smaller parietal side branches originate 
throughout the length of the aorta and include bronchial, intercostal, phrenic and lumbar arteries. A 
number of anatomical variants and accessory branches have been described. Approximately 15% to 
30% of individuals have one or more accessory renal arteries. The hepatic arteries can originate as a 
separate branch from the aorta, or as replaced branches from the left gastric or SMA in 5% to 15% of 
individuals1. In addition to accessory or replaced anatomy, the diameter, location and angle of the 
visceral arteries have significant variation, which may have implications with respect to arterial 
hemodynamics.  
3.2 Pathophysiology 
Aortic aneurysm is a progressive disease characterized by structural deterioration, gradual 
expansion, and eventual potential for rupture of the aorta if left untreated. The definition of aortic 
aneurysm is a localized or diffuse dilatation encompassing all three layers of the aorta with diameter 
>50% larger than the expected normal aortic diameter.   
An aneurysm which spans both the thoracic and abdominal cavities defines a thoracoabdominal 
aortic aneurysm.  The expansion rate of thoracoabdominal aneurysms ranges from 2-4mm per year and 

 
 
 
Page 20 of 103 
 
is not influenced by the size of the aneurysm at the time of diagnosis2,3.  The expansion rate of 
thoracoabdominal aneurysms does not appear to increase as individual aneurysms enlarge.  The 
presence of COPD and hypertension are factors associated with an increased rate of enlargement4,5.  
Thoracoabdominal aortic aneurysms become a risk for rupture if they are above 5.5-cm in diameter or 
if they are less than 5.5-cm in diameter and are growing more rapidly than 0.5-mm in 6 months.  The 5-
year survival of thoracoabdominal aneurysm patients ranges from 7-20% depending on the percentage 
of aneurysms secondary to aortic dissection3,6.  Half of the thoracoabdominal aneurysm deaths are 
attributed to rupture and the other half are due to some sort of comorbidity such as myocardial 
infarction.  The overall survival of thoracoabdominal aortic aneurysm patients is often overestimated, 
because the patients with advanced comorbid medical illness are not included and account for 46-68% 
of the patients reported in past natural history studies3,6-9.  Dissecting aneurysms have a higher rate of 
rupture and have a worse prognosis without intervention. 
Most patients with a descending thoracic or thoracoabdominal aneurysm do not have symptoms 
when first diagnosed7,10.  They are likely diagnosed with a CT scan for another disease.  Some patients 
have vague chest, back, flank, or abdominal pain.  The pain may increase in severity as the aneurysm 
enlarges, or it may be sudden due to rapid expansion and impending rupture.  Symptoms can result 
from compression of or erosion into adjacent intra-thoracic structures or bony thorax7,11,12.  Hoarseness 
from stretching or compression of the left recurrent laryngeal nerve, tracheal deviation, persistent 
cough, or other respiratory symptoms are sometime seen.  Patients with a thoracoabdominal aortic 
aneurysm may have a palpable pulsatile mass in the upper abdomen.   
 
 

 
 
 
Page 21 of 103 
 
3.3 Treatment Options 
3.3.1 Medical Management 
Medical management of both fusiform thoracoabdominal aneurysms and type B aortic 
dissections includes normalizing blood pressure to prevent further dilation or dissection.  Close 
monitoring should be performed.  Operation should be limited to patients whose aneurysms are at least 
5.5-cm in diameter, whose symptoms persist, whose aneurysms enlarge and are at least 4.5-cm in 
diameter, or who develop evidence of bleeding.  But if any of those conditions are observed (persistent 
symptoms, aneurysm enlargement, and evidence of bleeding), the patient should be offered repair.  For 
dissections operation is suggested for symptomatic patients and those with complications including 
malperfusion syndrome or active hemorrhage.  For prior repair, if there are persistent endoleaks, loss of 
seal, or device integrity issues of previously placed graft material repair should be offered. 
3.3.2 Open Surgical Repair 
Open repair of thoracoabdominal aneurysms, especially in patients with preexisting 
comorbidities, is fraught with complications. A meta-analysis of 7,833 open repairs of 
thoracoabdominal aneurysm repairs from 2000 to 2010 found a 30 day mortality rate of 7%, in-hospital 
mortality of 10%, spinal cord ischemia rates of 7.5%, renal failure rates of 19%, and pulmonary 
dysfunction rates of 36%13.  Predictors of adverse events after elective open repair based on pre-
existing comorbidities have been established.  Advanced age (>70 years)14-17, respiratory disease16, 
renal insufficiency18, coronary artery disease14,17, symptomatic aneurysms, extent 1 and 2 aneurysms19-
22, and diabetes23 are reported to be a predictor of 30-day mortality.  Cardiac function24, extent 1 and 2 
aneurysms20,25-27, symptomatic cases27, and diabetes23 are reported to be predictors of paraplegia.  The 
outcomes reported above are in a low- to moderate- risk patient population.  It is a logical extension to 
assume the outcomes in moderate- to high- risk patients would be worse. 

 
 
 
Page 22 of 103 
 
3.3.2.1 Open Surgical Repair of Ruptured, Urgent, and Emergent TAAAs 
Open repair of any thoracoabdominal aneurysms, especially in patients with preexisting 
comorbidities, is fraught with complications. A recent review of emergent patients with a ruptured 
TAAA looked at the overall mortality of 51 emergently treated patients with TAAA between 1994 and 
2014.  The study evaluated Crawford Type I, II, III, and IV presenting hemodynamically unstable 
(94%) and hemodynamically stable (3%).  In this study 54.9% (28/51) had true aneurysms and 45% 
(23/51) had dissecting aneurysms.  These were further broken into 94% (48/51) that presented 
emergently requiring treatment in 2-6 hours and 6% (3/51) that presented urgently and required 
treatment within 24 hours.  The overall mortality in this study was 43% (23/51); 15% (8/51) of these 
occurring during the procedure and 27% (14/51) occurred post-operatively.  Of the 84% (43/51) that 
survived the initial procedure, 16% (6/42) developed paraplegia/paraparesis, 18.6% (8/43) had acute 
renal failure, 35% (15/43) had pulmonary insufficiency, and 18.6% (8/43) with post-operative bleeding.  
The average visceral ischemic time was 36 minutes and the average blood loss was 2875cc28.   
3.3.2.2 Open Surgical Repair of Chronic Type B Dissections 
Open repair of chronic type B dissections is known to have a higher mortality and morbidity 
rate.  A 2014 review of open and endovascular outcomes for patients with chronic type B dissections 
cited an operative mortality of 6%, stroke rate of 16%, and paraplegia of 9%.  The one year major 
morbidity or mortality in these open repair patients was 25%29.   Another large study evaluating open 
repair results in 1542 subjects reported a 30-day mortality of 17.8% 30.  One advantage of open repair 
compared to endovascular repair of type B dissections is a lower re-intervention rate29.   
 
 

 
 
 
Page 23 of 103 
 
3.3.2.3 Open Surgical Repair of TAAAs with Prior Aortic Repair or Obstructive Stenting 
The risk of increased mortality and complications in redo open TAAA repair suggest that a less 
invasive approach such as endovascular repair is warranted.  Numerous single site articles have been 
published regarding branched or fenestrated aneurysm repair following a prior aortic repair.  The prior 
repairs documented include endoluminal abdominal aortic aneurysm repair, aorto-bifemoral bypass, 
and open repair with a tube prosthesis for post-operative complications including Type I endoleak, 
suprarenal extension of the aneurysm, and anastamotic aneurysms 31.  The most common risks and 
complications documented in the endovascular repair of a previous intervention include Type III 
endoleaks at the modular joint and the increased graft on graft friction making graft maneuverability 
and repositioning difficult.  Despite the risks, it was determined that the option of endovascular repair 
may be advantageous to this group of patients with a history of multiple abdominal operations or with 
serious cardiopulmonary risk factors as compared with the more invasive open surgical repair32.   
3.3.3 Endovascular Repair 
3.3.3.1 Parallel Grafts 
Parallel grafts (often referred to as snorkels, chimneys, periscopes, or CHIMPs) are 
combinations of aortic and branch stent grafts deployed simultaneously.  They are typically all straight-
tube grafts where the open end is either on the proximal or distal extent (and sometimes both) of the 
aortic component.  The combination of straight tube stent grafts allows for the physician to treat 
emergent patients’ beings the assembly does not need to be custom made.  There are some criticisms 
though about the lack of circumferential seal and fixation though with parallel grafts.  This lack of 
circumferential seal and fixation may leave the patient vulnerable to endoleak. 

 
 
 
Page 24 of 103 
 
There have been case reports which describe two parallel stent graft techniques used to repair 
thoracoabdominal aneurysms.  The first ‘terrace technique’ has two chimney stents in contact with a 
more proximal thoracic graft and two chimney stents in contact with a more distal thoracic graft33.  The 
second has two chimney stents going to the celiac and superior mesenteric arteries.  Then there are two 
snorkel stents pulling retrograde flow and going to the renal arteries34-36.  
Snorkel and chimney grafts can be implanted with good technical success rates if care is taken, 
but long-term renal function is in question.  Seal and fixation are also in question, so the parallel graft 
techniques should be avoided in elective settings and reserved for emergent settings37.  A recent review 
found that 10.7% of patients in the literature treated for thoracoabdominal aneurysm with parallel grafts 
experienced type 1 endoleak.  The investigator thought the approach would be useful for a recovery 
maneuver or for emergent cases where fenestrated grafts are not readily available, but long term 
durability and proximal fixation remain in question38.  
3.3.3.2 Sandwich Techniques 
Two sandwich techniques have been proposed in order to care for patients with an off-the-shelf 
approach.  The first used dual bifurcated infrarenal grafts in the descending thoracic aorta39.  The 
second used 3-4 bridging stents sandwiched with a thoracic graft in the descending thoracic aorta40.  
While these sandwich techniques can be used off-the-shelf, they do not provide for circumferential seal 
and fixation, and long-term durability is in question. 
3.3.3.3 Fenestrated Stent Grafts 
While combinations of branched and fenestrated endografts can be specified and ordered from 
manufacturers to be customized for the patient in Europe, there are few studies of purely fenestrated 
endografts used in the repair of thoracoabdominal aneurysms.  A study showed the technique by which 

 
 
 
Page 25 of 103 
 
endografts can be modified in order to treat urgent cases of thoracoabdominal aneurysms41.  These 
authors recently published a case where this technique was used to repair a thoracoabdominal aneurysm 
in a 74-year-old male patient with very asymmetric visceral and renal vessels.  The repair was done by 
sewing Gore Viabahns to the fenestrations as ‘mini cuffs’ which helped to increase the amount of seal 
obtained.  The patient had been followed for two months42.  Also, a retrospective study in 2011 which 
reviewed the cases done in Paris, France and Cleveland, Ohio for type 4 thoracoabdominal aneurysms 
with custom manufactured fenestrated grafts was reported.  All patients were considered high risk for 
open repair.  Over a six-year period, 231 patients were treated.  Thirty-day mortality was 2.6% and 2-
year survival was 83%.  Freedom from secondary intervention was 93% at 30 days and 73% at 2 
years43.   
3.3.3.4 Cook t-Branch Stent Grafts 
Branched stent grafts have been used for juxtarenal and pararenal aneurysms.  Modified 
branched stent grafts have only been reported to be used with thoracoabdominal aneurysms to date42,44.  
There are no large-scale studies of unibody axially oriented multi-branched grafts for pararenal 
aneurysms as they are more frequently used for thoracoabdominal aneurysms.   
Branches have been attached to the aortic component to provide for bridging stent overlap, 
increased overlap encouraged seal and fixation.  It also allowed for the use of self-expanding stent 
grafts which help accommodate tortuosity.  Several variations of branch orientation exist including 
axial, helical, antegrade, and retrograde.  Axial branches were deployed proximal to the target vessels.  
The branches were cannulated from an arm approach, and mating stents were deployed.  Bard Fluencies 
were commonly used, and the length of overlap was typically 10-mm.  These were sometimes lined 
with balloon-expandable stents to prevent component separation.  Alignment between the axial branch 
stent and target vessel was noted as a problem if it caused angulation in the bridging stent, potentially 

 
 
 
Page 26 of 103 
 
leading to bridge stent kink.  To increase durability, self-expandable bare metal stents such as Boston 
Scientific Wall stents were occasionally used.  The helical branches exit the aortic component 
posteriorly and wrap around the main body.  The distal end landed 10-mm from the ostium of the target 
vessel.  The longer overlap and gentle sweeping centerline made lining the stents less critical.  The 
branch stent curved to become in-line with the target vessel.  The drawback was that the helical stents 
make for a bulky construct requiring a large diameter delivery system. 
3.3.3.5 Flow Diverting Devices 
Flow diverting stents are used in limited applications for repairing thoracoabdominal aortic 
aneurysms in Europe. They provide for more simplified implant in that the branch vessels do not need 
to be stented.  Instead the three-layer micro-woven nitinol mesh significantly slows and alters the flow 
of blood into the aneurysm sac encouraging thrombus formation.  All the while, flow channels are 
developing to the branch vessels45-47.  The IFU must be followed very closely so that the stents do not 
overlap graft cloth, that 20-25% oversizing is followed, and so that larger stents are always deployed 
within smaller stents.  If these instructions are not followed, devastating ruptures may follow48-50.  Data 
is limited and largely retrospective in nature51.  The one registry reported had 380 patients but showed a 
technical success rate of 0% when the IFU was not adhered to (n=38/38)52. 
3.3.3.6 Endovascular Repair of Ruptured, Urgent, and Emergent TAAAs 
There are no reports we found describing branched grafts being used for TAAA repair in a 
ruptured or emergent setting.  This is likely due to either manufacturer control of the use of the devices 
or control of the publication of information.  However, there are several studies of parallel grafts being 
used in this setting.  A meta-analysis published revealed 15 reports of 93 such patients.  24.7% were 
operated on in an urgent setting, but the results were not compared to results of patients treated in a 

 
 
 
Page 27 of 103 
 
non-urgent setting.  Because of this we cannot draw any conclusions38.    A further study examined 
parallel grafts used in ruptured thoracoabadominal aortic aneurysms and pararenal aneurysms used in 9 
patients (6 thoracoabadominal aortic aneurysms, 2 pararenal aortic aneurysms, and 1 short neck 
infrarenal aneurysm).  The study mentions stable renal function in all patients and a very low 30-day 
mortality rate36.    Yet another study examined 29 patients treated with the parallel graft technique of 
these14 patients were ruptures and 15 patients were symptomatic.  Nine lesions were in the aortic arch, 
ten were in the descending aorta, and ten were in the branched visceral segment.  Twenty-two were 
treated in the first 24 hours and 7 were treated in the first 3 days.  Median follow-up was 2 years.  There 
were four 30-day deaths (1 cerebral infarct, 1 visceral ischemia, 1 multiple organ failure, and 1 heart 
failure).  The authors remarked that this technique is promising with low rates of early mortality when 
considering that the patients were emergent53.  Three additional cases were reported but the cases 
focused mainly on technical feasibility and endoleaks, as a means of demonstrating the technique with 
little focus on the clinical sequelae that may develop during urgent repair of thoracoabadominal aortic 
aneurysms with endovascular techniques54-56.    From this limited data set coupled with our current 
understanding of the outcomes of patients treated with open repair in the urgent setting, it appears that 
the benefit of endovascular repair may outweigh the risks.   
3.3.3.7 Endovascular Repair of Chronic Type B Dissections 
Incidence rates of aortic dissection is estimated to be roughly 3 per 100,000 people per year57,58.  
Until recently acute Stanford type B aortic dissections were managed with blood pressure control59,60.  
If endovascular intervention is offered in acute dissections the goal is typically to cover the proximal 
entry tear in order to block antegrade flow to the false, lumen. This starts the process of aortic 
remodeling by depressurizing the false lumen61.  If only the thoracic aorta is to be treated, growth of the 
true lumen and shrinking of the false lumen are generally not associated with distal reperfusion or 

 
 
 
Page 28 of 103 
 
endoleak – meaning there is a lower rate of reintervention62.   As endovascular repair is becoming more 
prevalent, we are learning that chronic dissections tend to have a thicker fixed septum which leaves the 
aorta less susceptible to remodeling after repair63.  Therefore, treating acute Type B dissections with 
blood pressure management may not be the best approach, because if endovascular repair is needed 
later the process of remodeling may not happen.  If the aneurysm and dissection extend distally beyond 
the diaphragm, the types of fenestrations that are found in extensive Stanford type B dissections leave 
the patient prone to distal reperfusion of the false lumen even after cover of the proximal entry tear 64,65.  
These patients will require some sort of branched or fenestrated repair.  If the patient has an aneurysm 
complicated by type B dissection where visceral branches arise from both true and false lumen the 
treatment options are even further limited, and bridging stents will have to cross the septum increasing 
the technical difficulty of completing the case.  Small true lumens and visceral arteries arising from 
either true- or false- lumen and dissection extending to branches have made endovascular repair 
sometimes near impossible.   
3.3.3.8 Endovascular Repair of TAAAs with Prior Repair or Obstructive Stenting  
The risk of increased mortality and complications in redo open TAAA repair suggest that a less 
invasive approach such as endovascular repair is warranted.  Numerous single site articles have been 
published regarding branched or fenestrated aneurysm repair following a prior aortic repair.  The prior 
repairs documented include endoluminal abdominal aortic aneurysm repair, aorto-bifemoral bypass, 
and open repair with a tube prosthesis for post-operative complications including Type I endoleak, 
suprarenal extension of the aneurysm, and anastamotic aneurysms 31.  The most common risks and 
complications documented in the endovascular repair of a previous intervention include Type III 
endoleaks at the modular joint and the increased graft on graft friction making graft maneuverability 
and repositioning difficult.  Despite the risks, it was determined that the option of endovascular repair 

 
 
 
Page 29 of 103 
 
may be advantageous to this group of patients with a history of multiple abdominal operations or with 
serious cardiopulmonary risk factors as compared with the more invasive open surgical repair32.   
3.3.3.9 Staged Endovascular Repair 
3.3.3.9.1 Planned Staged Procedures 
Staged procedures have been used in endovascular repair of thoracoabdominal aortic aneurysms 
in an effort to limit the incident and severity of spinal cord ischemia.  The hypothesis behind this is the 
staging of procedures allows for the development of a collateral network.  The collaterals would 
maintain some perfusion and allow other vessels to compensate reducing the overall impact of spinal 
cord ischemia.  One center studying 87 Type II subjects found that staging reduced the overall SCI 
rates significantly66.  The SCI rate in single stage procedures was 37.5% (12/32) and 11% (3/27) in 
two-stage procedures.   The rate was slightly higher in unintentionally staged procedures at 14% (4/28).  
Unintentional staging was defined as prior aortic repair, 21% (6/28) had prior thoracic repair and the 
remainder were abdominal aortic repair.  In the staged procedures, the two-stage repair SCI events were 
all temporary and resolved by discharge and the unintentional staging had 10% (3/28) that resulted in 
permanent SCI.  This study had a median time between stages of 5 months (range 1-60 months), but the 
investigators believe 2-3 weeks to be optimum66.  The investigators also noted that symptomatic 
patients should be monitored and considered for earlier repair.  While there is no specific length of 
aortic coverage to determine the threshold where one should consider staging, this study cites that 
aortic coverage of 200 cm or greater may indicate the threshold where subjects would benefit from 
staging.   
There are several techniques used for staging endovascular TAAA repair.  Techniques include 
coverage of the proximal thoracic aorta up to the celiac artery in a staged procedure with visceral 

 
 
 
Page 30 of 103 
 
stenting performed at the completion procedure.  Other techniques reference placing the main aortic 
stents, but allowing perfusion from an open celiac branch, perfusion branches, or unstented 
contralateral iliac limb67.  The use of perfusion branches may be preferred to allow for better 
hemodynamics and avoid excessive pressurization of the aneurysm sac.   
3.3.3.9.2 Bail-out Staged Procedures 
 
There is limited information available on use of staging as a bail-out-procedures.  Several sites 
and investigators discuss alternative techniques such as chimney and snorkels as alternative techniques 
to be used in technically challenging cases complicated by anatomy68, but fail to reference the use of 
staging and outcomes.  Literature also cites several intra-operative techniques for bail-out maneuvers in 
the operating room69, but currently available TAAA technologies do not allow for staging of the aortic 
components and limited data is available on the outcomes of these cases.   
3.3.3.10 Summary of Alternative Treatments 
A few endovascular options are available for treating thoracoabdominal aneurysms.  A limited 
number of centers have access to commercially available branch-fenestrated devices, but they typically 
require customization.  This customization has an associated lead-time of several weeks.  The 
endovascular options present a real problem of patients not being able to either travel to the select sites 
or being emergent and not having the time to wait for a custom graft.  In these instances, it may 
appropriate for the patients to be treated either with off-label devices (sandwich approach) or with 
physician-modified endografts.   Sandwich configurations tend to have excellent patency rates but lack 
circumferential seal and fixation.  Branch-fenestrated grafts have good seal and fixation but tend to 
have high frequency of reintervention and can be limited by patient anatomy.  In all instances careful 

 
 
 
Page 31 of 103 
 
case planning is in order and all aspects of parallel grafts as well as branch-fenestrated grafts should be 
carefully considered relative to individual patient anatomy. 
3.3.3.10.1 Summary of Treatments for Staged Procedure or Staged Bail-out Procedure 
Due to the proximal seal zone of this device, several options are available to stage patients with 
either a planned procedure or as a bail-out procedure.  Literature supports the hypothesis that a 
controlled endoleak or perfusion branch can be protective for SCI events by helping create a protective 
collateral network.  When planned visceral artery bridge endoleak can be provided via a low risk staged 
procedure that does not put the patient at significant risk from the intervention.  The use and experience 
with staged procedures as a bail-out method is not widely understood, but still allows the patient to 
maintain perfusion to the visceral vessels and lower extremities while they recover and prepare for 
completion of the procedure.  The bail-out staging method is only intended to be used in extreme 
circumstances when patient status declines intraoperatively or unforeseen technical challenges are 
encountered.   
3.4 Benefits and Risks of Treatment Options 
3.4.1 Open Surgical Repair 
Contemporary series have shown that open repair of thoracoabdominal aneurysms, is associated 
with a significant mortality risk and increase in major complications. One report describes 7,833 open 
TAAA repairs from 2000 to 2010 found a 30 day mortality rate of 7%, in-hospital mortality of 10%, 
spinal cord ischemia rates of 7.5%, renal failure rates of 19%, and pulmonary dysfunction rates of 
36%13.  The risks of open repair are significantly higher than any other option for repair.  Open repairs 
are durable but have substantial perioperative mortality and postoperative morbidity.  Additionally, due 
to existing comorbidities and the high risk for complications this is not an option for many patients.   

 
 
 
Page 32 of 103 
 
3.4.2 Endovascular Techniques 
There is limited availability of data reporting the results of endovascular repair of 
thoracoabdominal aneurysms.  Many of these techniques require off-label use or modification of the 
grafts, which bring into question the safety and long-term durability. The literature suggests that 
snorkel and chimney grafts can be performed with decent technical success rates, but seal and fixation 
and long term durability are in question and have not been formally evaluated37.  A recent review found 
that 10.7% of patients in the literature treated for thoracoabdominal aneurysm with parallel grafts 
experienced type 1 endoleak.   
A 2004 to 2006 study of the novel t-branch device (Cook Medical) was studied in high risk 
subjects.  The study showed a technical success of 93%, thirty-day mortality of 5.5%, major 
perioperative complications 14% including paraplegia 2.7%, new onset dialysis 1.4%, respiratory 
failure 6.8%, myocardial infarction 5.5%, and stroke 1.4%.  All-cause mortality at twelve months was 6 
subjects.  There was no evidence of stent migration or aneurysm growth over the twelve month 
period70.     
In a study of type 4 thoracoabdominal aneurysms with custom manufactured fenestrated grafts 
over a six-year period, 231 patients were treated.  Thirty-day mortality was 2.6% and 2-year survival 
was 83%.  Freedom from secondary intervention was 93% at 30 days and 73% at 2 years43.   
Experience with the t-branch device evaluating 22 patients between 2010 and 2013 reported a 
technical success of 100%.  The re-intervention rate at 6 months was 90%, branch occlusion was 14%, 
paraplegia was 5%, and paraparesis in 5%.  Again, these lack long-term data to address the durability of 
the stent grafts.  In all endovascular options, close surveillance is mandatory for early identification of 
visceral or branched vessel stenosis or pre-occlusion.   

 
 
 
Page 33 of 103 
 
A retrospective study reported by Sanford Health (IDE Application G140207, Clinical Use 
Summary) reports the only subjects that would not be ideal candidates include subjects with prior 
suprarenal fixation stents, dissection, present emergently.  The retrospective study examines 12 patients 
which meet the clinical study criteria that were treated between 2012 and 2014.  In this patient 
population, there was one subject with renal failure and one subject with a respiratory event in the first 
30 days.  There was one unrelated patient death and one CVA in the first year.  Additionally, in this 
study there was one instance of branch vessel occlusion and secondary intervention.   
A large number of subjects may benefit from alternative endovascular treatments that may be 
performed with less risk of complications and shorter recovery time.  For these subjects, endovascular 
repair with a manifold system that is not based on patient anatomy may be the only treatment option.   
This patient population is faced with a serious and life-threatening disease and have limited 
clinical options.  The subjects are willing to assume a higher degree of risk with an investigational 
device due to the progressive nature of the disease and the high mortality and morbidity rates when left 
untreated.   
3.4.2.1 Staged Procedures 
With the Valiant Thoracoabdominal Stent Graft System, the risks of planned staging via the visceral 
artery bridge endoleak are comparable to the single stage procedure in the current protocol. We do not 
believe staging presents any new risks that are not currently covered under the risk profile for the 
VTAAA system, but these risks may happen at a higher frequency.  These risks still present no greater 
risk than the probable risk from the progression of the patient’s condition.  The increased risks for a 
planned stage procedure (visceral artery bridge endoleak or delayed distal seal) are risks from an 
additional procedure including anesthetic and contrast exposure, compounded physiologic insult from 

 
 
 
Page 34 of 103 
 
multiples procedures, access site complications, wire injury, device integrity issues from component 
interaction, paraplegia, spinal cord ischemic event, aneurysm enlargement, aneurysm rupture, and 
death.  Increased risks for a bail-out staged procedure include the above risks and increased procedure 
time or failure to treat.    
3.4.3 Stent graft designs 
 
The manifold system has the advantage of being independent of patient anatomy allowing for 
use off-the-shelf.  It can also adapt to numerous anatomical variations including tortuosity and vessel 
location.  The design allows for continuous flow to the visceral and infrarenal segments throughout the 
procedure.  Additionally, the proximal deployment and delayed distal seal allows for more flexibility in 
stenting the visceral vessels, multiple bail outs, or staging of the procedure throughout device 
deployment.  The importance of proximal deployment and gradual sweeping branch stents has been 
reported as a critical element for maintaining vessel patency71.   
3.4.4 Analysis of bridging stent characteristics 
 It has become evident that the use of the appropriate bridging stent including placement and 
stent is necessary to minimize risk of target vessel occlusion and kinking71.  The ideal stent has not 
been determined or standardized, but currently a balloon expandable stent covered is preferred.  The 
use of a covered stent has the advantages of optimal seal, minimizing risk of endoleak, and improved 
patency rates72.  The three most widely used stents are the iCAST covered stent (Atrium Medical), 
VBX (W.L. Gore), and the JoMed stent (Abbott).  The iCAST covered stent has been widely used and 
reported in the literature, and was the most frequently used stent in the recent GLOBALSTAR registry, 
with only five of 889 visceral arteries lost during follow up73. In a study of 234 VBX stents placed, 
100% technical success was noted and at 9 months, patency was 97% in 132 patients82.  The JoMed 

 
 
 
Page 35 of 103 
 
stent has been also widely used and it is the balloon expandable covered stent of choice by the 
Cleveland Clinic group, with recent report of >95% 5-year visceral artery patency among 632 subjects 
treated by fenestrated endografts74.  The long-term risks of stent fracture and dislodgment have not 
been systematically reported but seem to be exceptionally low with adequate selection of proximal 
landing zone.  The Fluency stent (Bard Peripheral Vascular, Tempe, AZ) has been used by one 
investigator, with excellent patency rates and low risk of kinking or stent fracture75. 
3.5 Justification for Specific Patient Selection Criteria Relevant for this Study   
Treatment of TAAA aneurysms in all patients will be considered for this study.  All patients 
diagnosed with a TAAA repair are considered high risk due to the natural history of a patient with a 
TAAA.  Their options are limited for endovascular repair and due to the comorbidities in this 
population they are all high-risk open repair.  Additionally, all patients undergoing open surgical repair 
of a thoracoabdominal aneurysm are considered to be at high risk for comorbidities and complications.  
Based on initial clinical experience, we believe that we can treat all patients with outcomes better to 
those of open surgical repair.  The current approach is an endovascular repair with lower surgical 
morbidity and mortality rate compared to open repair.  Endovascular repair may also decrease the 
recovery time and length of hospital stay.  From the initial clinical evaluation, certain patients may not 
be good candidates for this approach have been identified.  This patient population includes patients 
presenting emergently, with compromised renal access, or dissections.  The inclusion and exclusion 
criteria for this study has been refined to present a patient population that we feel may significantly 
benefit from this procedure without undue risk.  The inclusion criteria listed in section 4.4.2 including 
aneurysm characteristics, access vessel morphology, minimum neck length, diameter of aneurysm, 
branch vessel size, patency of the four major visceral vessels, and size of distal fixation site are required 

 
 
 
Page 36 of 103 
 
as inclusion criteria to achieve an adequate seal zone and optimal placement with the stent graft and 
branches.   
The patient population being excluded from this study includes patients with a ruptured 
aneurysm (or contained rupture), obstructive stenting of the visceral vessels, or a dissection in the 
treated portion of the aorta.  Also, patients with thrombus or excessive calcification within the neck of 
the aneurysm will be excluded as they put the patient at high risk of aneurysmal rupture or embolic 
event during surgical manipulation.  Anatomy that does not allow for primary or assisted patency of the 
left subclavian artery will be excluded because it is required for access.  Additionally, anatomy that 
would not allow for maintenance of at least one patent hypogastric artery will be excluded in order to 
prevent organ and/or pelvic ischemia and paraplegia.     
3.5.1 Rationale for Exposing Target Population to Potential Risks of Staging 
The planned staged method via the visceral artery bridge endoleak and delayed distal seal has 
been used successfully in 6 cases under PS-IDEs G170048 and G170024; 4 patients had their aneurysm 
successfully excluded (3 via the visceral artery bridge endoleak and 1 via delayed distal seal) in a 
staged fashion with 2 patients awaiting completion (1 via the visceral artery bridge endoleak and 1 via 
delayed distal seal). (Dr. Murray Shames, IDE G170024 and Dr. Thomas Maldonado, IDE G170048).   
There were no intra-operative deaths or SCI events, supporting that the device when used in planned 
staged procedure can be implanted safely and repeatedly.  When compared to literature reported SCI 
rates for single stage TAAA procedures, this is a viable option for patients at higher risk for SCI events.  
Given the success we have experienced with patients treated to date and the low risk of the completion 
procedure, we feel that it is justified to expose the target patient population to the potential risk.   
3.5.2 Emergent/Urgent/Ruptured Aneurysms 

 
 
 
Page 37 of 103 
 
A ruptured aneurysm is either an emergent or urgent situation and many times is fatal carrying 
an overall mortality rate of 90%.  Ruptures present in many different ways.  One study states that 80% 
of ruptures present as a retroperitoneal rupture76.  A retroperitoneal rupture can lead to slow progressive 
bleeding which forms a large hematoma that is contained by the periaortic tissues.  Approximately 4% 
of ruptured aneurysms are contained ruptures.  Surgical treatment is recommended within 24 hours of 
presentation of a contained rupture.  An acute ruptured aneurysm requires immediate intervention and it 
is said that endovascular techniques may improve the survival for patients with ruptured aneurysms76.   
In a combination of retrospective and prospective IDE data from other sites (G140207), there 
have been 3/33 subjects treated emergently and 3/33 subjects treated urgently.  Of the three treated 
emergently, there were no intraoperative deaths.  All of the emergent subjects had prior open repair that 
failed and were left with at least one major complication from prior open surgery.  One died on day 14, 
one was discharged and presented with an acute onset of paraplegia and passed away at 30 days, and 
one survived to 3 months.  Recent results have reported the mortality rate of emergent/urgent open 
repair to be 43% with the average visceral ischemic time of 36 minutes with average blood loss of 
2875cc28.  Another center reported a 36.8% 30-day mortality in patients treated with a hybrid 
approach77.  Comparison of this study with prior results of open repair and the fact that there was no 
ischemic time and an average blood loss of 1250 cc in emergent cases from prospective IDE data, the 
probable risk of the using the investigational device is no greater than the probable risk of open repair 
or from the disease.   
Three subjects were treated urgently requiring repair within one week of presentation.  One 
subject treated urgently was doing well at his 30-day visit and succumbed to a hemorrhagic stroke at 35 
days, one died of leukemia at 14 months, and one is nearing her three-year visit and is doing well.  Of 

 
 
 
Page 38 of 103 
 
the subjects treated urgently, none of them died of aneurysm or device related deaths and all but one 
survived past one year.     
Presentation of a subject requiring emergent treatment needs to be treated immediately while 
urgent treatment needs to be completed within a week of presentation.  Due to the many comorbidities 
of these subjects, an open repair is not recommended for the same reasons as an elective open 
procedure.  Therefore, we feel that treatment with this investigational device is warranted to minimize 
the risks associated with open repair.  This device is an endovascular option that can be used off the 
shelf and delivered quickly to treat an emergent case while reducing the procedure time and overall 
blood loss.  Due to the high overall mortality of open repair, the probable risk of the investigational 
device is no greater than the probable risk from the subject’s condition.  While these subjects would 
benefit from the investigational device, these subjects should not be included in the primary study arm 
as the expanded selection criteria could present confounding results making it challenging to separate 
the safety and effectiveness of the device from the underlying disease process.   
3.5.3 Type B Dissections 
A Stanford type B dissection begins distal to the brachiocephalic artery.  We plan on treating 
both type B dissections that are subacute and chronic with aneurysmal changes.  Treating dissection 
subjects involves determining the true and false lumens and which lumen feeds the visceral vessels.  
The visceral manifold device design does not mimic natural anatomy and has the ability to cross 
between true and false lumen to treat the dissection, feed the visceral vessels, and accommodate the 
device even in a small true lumen by utilizing both the true and false lumen as conduits to complete the 
case.  Our device can cross between naturally occurring fenestrations or a laser may be used to create a 
fenestration between the true and false lumen.  The risks of using a laser to create fenestrations include 

 
 
 
Page 39 of 103 
 
perforating the aorta or branch vessels, extension of the dissection, vascular trauma, embolism, 
pseudoaneurysm, and bleeding.  These risks will be mitigated by utilizing the smallest possible laser 
and using fluoroscopic guidance to locate and create the area for the fenestration.  The risk of potential 
dissection extension in chronic type B dissections is very low.  The risk of potential dissection 
extension is higher in subacute type B dissections and would be mitigated by controlling blood pressure 
while deploying, conservative oversizing of the stent graft, and having a cardiothoracic surgeon 
available if there is a retrograde dissection.   
A large number of these patients have been excluded from that study for dissection. 15% (5/33) 
of subjects were treated electively for TAAA with a dissection (G140207). A laser was used to 
perforate the aortic wall between the lumens to allow for placement of the graft and limbs when a 
natural fenestration is not found.  All of the procedures were successful and there were no device 
related events or disease related mortalities. Type II endoleaks were observed in 2 of the 5 subjects but 
have not required intervention or lead to aneurysm enlargement. 60% (3/5) of these subjects are doing 
well at two years post procedure. Of the two that are deceased, one died of a CVA at four months while 
the other death was self-induced due to alcohol abuse post procedure.  Literature cites an in-hospital 
mortality rate of 29% for open surgical repair of type B dissection.  Given the small population treated 
with the branched endograft to date with no mortalities related to the device or the dissection, we 
believe the patient population presenting with type B aortic dissection involving the visceral segment 
could benefit from the use of this device over currently available options.  These subjects should be 
included in the expanded selection arm rather than the primary study arm due to presentation with a 
concomitant disease process that falls outside the study’s intended use.   
3.5.4 Aneurysm with Renal Insufficiency 

 
 
 
Page 40 of 103 
 
Subjects with known renal insufficiency and renal failure are excluded from the primary study 
arm due to underlying renal insufficiency that increases their risk of peri-operative renal failure 
confounding the differences between the efficacy of the device and the underlying disease process.  
This device would still be beneficial for this subject population because it allows for continued 
perfusion of the renal arteries and may in some instances treat underlying causes for renal insufficiency.   
A 2004 report that evaluated the outcomes of aneurysm repair in patients with established renal 
failure reported that subjects presenting with chronic renal impairment have a high incidence of 
concurrent cardiovascular morbidity and are at high risk for aneurysm disease.  They also reported that 
aneurysm subjects with renal dysfunction that were non-operative had a 20% 5-year survival rate, with 
39% of subjects dying from rupture of their aneurysm.  One study cited a 25% mortality in subjects on 
hemodialysis and 67% of subjects with renal insufficiency (creatinine >4 mg/dl) requiring post-
operative dialysis78.  Several precautions are put into place to protect renal function during the 
procedure including hydration, a minimal volume of nonionic contrast agent, and continual monitoring 
of post procedure creatinine levels.  Subjects undergoing dialysis at the time of procedure will be 
dialyzed before and after the procedure to protect any remaining renal function. One research study 
indicates that elevated creatinine levels don’t indicate post-op renal failure and that the creatinine level 
may not be a contraindication for EVAR treatment if proper precautions are used79.      
3.5.5 Aneurysms with Small Branch Vessels <5 mm 
Some patients with Marfan disorder of the aorta have already had proximal surgical and/or 
combined endovascular repair of the proximal thoracic aorta.  In such cases, thoracoabdominal 
aneurysm disease may mandate treatment while open surgical repair is generally recommended l, 
patients who are not fit for open surgical repair represent a subset of patients not served with available 

 
 
 
Page 41 of 103 
 
techniques.  In such cases, opportunity exists to seal (consistent verbiage for graft) in preexisting 
proximal aortic synthetic graft, deploy visceral endo bypasses into native visceral arteries, and seal 
distally in either existing synthetic graft or native iliac vessels.   In this fashion, endovascular repair is 
accomplished without seal in Marfan aorta. 
3.6 Device Description and Drawings 
The VTAAA stent graft system is made up of two main body components and makes use of 
several off-the-shelf FDA-approved stent graft components (see Appendix B) for system drawing).  
The two custom main body grafts are the thoracic bifurcation (Figure 1A) and the visceral manifold 
(Figure 1B).  The thoracic bifurcation is deployed in the thoracic aorta and provides the proximal seal 
for the device.  For a Type I or II thoracoabdominal aneurysm the proximal seal is in zone 3 and for 
Type III and V the device seals in zone 4.  The smaller 16 mm limb of the thoracic bifurcation extends 
to the infrarenal segment to either seal in zone 9 for a Type I and V and in zone 10 for Type II and III. 
The two limbs of the thoracic bifurcation allow for continued aortic flow while deploying the visceral 
segment.  The visceral manifold is deployed within the larger 20 mm limb of the thoracic bifurcation to 
set the stage for the visceral debranching.  The branches of the visceral manifold extend to the visceral 
vessel with the use of covered bridging stents and provide distal seal of the manifold.   The smaller 16 
mm limb of the thoracic bifurcation extends to the infrarenal segment to either seal in zone 9 for a Type 
I and V and in zone 10 for Type II and III.  All other connections in the device make use of sizes that 
are modular and independent of patient anatomy. 
 
 

 
 
 
Page 42 of 103 
 
Figure 1: VTAAA Stent Graft System 
 
 
A 
B 
Figure 1: Images of the manufactured device A) the thoracic bifurcation main 
body graft and B) visceral manifold main body graft 
Aortic components 
The thoracic bifurcation stent graft (Medtronic) seals to the native aorta/healthy tissue and 
bifurcates blood flow in the descending thoracic aorta.  The distal end bifurcates into two smaller legs 
(20 mm and 16 mm) suitable for modular connection to the visceral manifold stent graft and the 
visceral bypass stent graft.  The thoracic bifurcation is composed of a self-expanding, metallic spring 
scaffold made from nitinol stents sewn to a polyester fabric graft with nonresorbable sutures and is 
manufactured in the following sizes:  
 

 
 
 
Page 43 of 103 
 
 
Table 1.  Thoracic bifurcation dimensions 
 
The proximal end of the visceral manifold stent graft (Medtronic) deploys into the 20 mm leg of 
the thoracic bifurcation and quadfurcates to perfuse the celiac, SMA, right, and left renal arteries via 
bridging stents.  The visceral manifold is composed of a self-expanding, metallic spring scaffold made 
from nitinol stents sewn to a polyester fabric graft with nonresorbable sutures and is manufactured in 
the following sizes: 
 
Table 2.  Visceral manifold dimensions 
Branch components 
 
The limbs of the visceral manifold are extended to the target branch vessel with 9-mm balloon 
expandable stents (Atrium, iCAST, W.L. Gore VBX).  The Atrium iCASTs and W.L. Gore VBX are a 
stainless-steel stent covered with a PTFE film and these are not modified by the physician.  The balloon 
expandable stents are overlapped to reach the target branch vessel and the distal end is appropriately 
sized to the branch vessel.  The interfaces between the branch components are lined with self-
expanding bare metal nitinol stents to improve resistance to kinking and stent graft separation.   

 
 
 
Page 44 of 103 
 
Iliac extension components 
The visceral bypass (Medtronic) deploys into the 16 mm limb of the thoracic bifurcation to 
perfuse the iliac segment.  The visceral bypass is composed of a self-expanding, metallic spring 
scaffold made from nitinol stents sewn to a polyester fabric graft with nonresorbable sutures and is 
manufactured in the following sizes: 
 
Table 3.  Visceral bypass dimensions 
 
The infrarenal bifurcation (Medtronic) deploys into the visceral bypass to bifurcate aortic flow 
to the iliac segments.  The infrarenal bifurcation is composed of a self-expanding, metallic spring 
scaffold made from nitinol stents sewn to a polyester fabric graft with nonresorbable sutures and is 
manufactured in the following sizes: 
 
Table 4. Infrarenal bifurcation dimensions 
 
The iliac limbs and extenders (Medtronic, Endurant II) will be utilized from a commercially 
available Endurant II limb or appropriately sized iliac limb extension stent graft.  These will be 
deployed in the infrarenal bifurcation and will provide distal seal of the stent graft system.  The iliac 

 
 
 
Page 45 of 103 
 
limbs will be available in the commercially manufactured sizes and appropriately oversized for 
implantation in the infrarenal bifurcation.   
Principles of Operation 
The VTAAA stent graft system works to bifurcate aortic flow upstream of the target visceral 
vessels.  This bifurcation has a two-fold benefit.  First it allows for aortic flow to be compartmentalized 
into a visceral segment and an infrarenal segment providing for uninterrupted flow to the visceral 
vessels as well as the infrarenal segment throughout the procedure.  If any of the connections cannot be 
made or the patient status declines during the procedure, then it can be staged, and the connections can 
be made at a later date.  Second, the upstream bifurcation encourages more favorable flow conditions in 
the bridging stents and target vessels which may prevent target vessel occlusion.  This is due to the fact 
that the bifurcations are upstream providing a sweeping transition into the renal arteries that is smooth 
providing for relatively laminar flow conditions.  The design demonstrates that more central aortic flow 
is obtained with this design increasing flow rates in the visceral vessels to potentially increase target 
vessel patency (Figure 2). 
The device can be used as an off-the-shelf system, negating the need for lead times associated 
with custom-built devices.  The critical sizing that will need to be done is with the proximal end of the 
thoracic bifurcation, distal landing zone in the aorta or iliac arteries, and the bridging stents.  The 
proximal end of the thoracic bifurcation can be sized by choosing any of the available sizes of the 
VTAAA stent graft system and the sizes of the bridging stents can be manipulated by choosing any of 
the commercially available sizes of the Atrium iCAST or W.L. Gore VBX.  The Atrium iCASTs or 
W.L. Gore VBX are added to the system in-vivo and connected with passive fixation which negates the 
need to size the main body components based on the target vessel sizes.  All other connections in the 
device make use of sizes that are the same, independent of patient anatomy. 

 
 
 
Page 46 of 103 
 
The deployment of this device is also independent of device alignment.  Angular alignment of 
the thoracic bifurcation and the visceral manifold has very little impact on the outcome of the case.  
Longitudinal alignment is more important, but a safety factor has been built-in by calling for the distal 
ends of the visceral manifold to be deployed above their target vessels by 1-2 cm.  The longitudinal 
landing should be optimized so that the graft is not landed too low so that the connection with the 
visceral vessels is challenging to make. 
 
 
 
 
 
 
 
 
 
 
Intended Use/Indications for Use 
The VTAAA stent graft system is indicated for the endovascular treatment of thoracoabdominal 
aortic aneurysm (Crawford Type 1, 2, 3, and 5) in patients with the following characteristics: 
 
Figure 2: Assembly drawing showing the thoracic bifurcation, the 
visceral manifold, the branch stents, and the infrarenal grafts, all 
deployed within an idealized aneurysm sketch. 

 
 
 
Page 47 of 103 
 
• An aneurysm with a maximum diameter of greater than or equal to 5.5 cm or 2 times the normal 
diameter just proximal to the aneurysm using orthogonal (i.e., perpendicular to the centerline) 
measurements 
• Aneurysm with a history of growth greater than or equal to 0.5 cm in 6 months 
• Saccular aneurysm deemed at significant risk for rupture 
• Symptomatic aneurysm greater than or equal to 4.5 cm 
• Axillary or brachial and iliac or femoral access vessel morphology that is compatible with 
vascular access techniques, devices or accessories, with or without use of a surgical conduit 
• Proximal landing zone for the thoracic bifurcation stent graft that has: 
o 
greater than or equal to 2.5 cm of non-aneurysmal aortic segment including 
previously placed graft material (neck) distal to the left subclavian artery (LSA) and 
diameter in the range of 26-42 mm 
o 
Adequate distance from the celiac artery, in order to accommodate cannulation from 
the antegrade access point when considering the total deployed length of the thoracic 
bifurcation and visceral manifold 
• Iliac artery or aortic distal fixation site, including both native tissue and previously placed graft, 
greater than or equal to 15 mm in length and diameter in the range of 8 – 25 mm 
• Age: greater than or equal to 18 years old 
• Life expectancy: greater than 1 year 
3.7 Potential Study Device Benefits and Risks Based on Leveraged Clinical Information 
 Patients diagnosed with TAAA have a poor natural history and require surgical intervention to 
extend life.  Several repair techniques have been developed, but each carry risk.  As discussed 

 
 
 
Page 48 of 103 
 
previously, open repairs are durable but have substantial perioperative mortality and postoperative 
morbidity.  Endovascular techniques are plagued by high procedural complexity and poor branch vessel 
patency.  Parallel techniques may have poor seal and may be prone to endoleak.  In contrast, the 
manifold approach has circumferential seal at the proximal end of the system.  It has relatively simple 
case planning and it has virtually no ischemic time.  Due to these advantages, we believe the novel 
proposed technique may overcome some of the current clinical risks with other approaches.   
 
Patients who participate in this study may benefit from having a less invasive procedure 
compared to open repair of their thoracoabdominal aortic aneurysm.  We expect the amount of 
discomfort, total blood loss, recovery time, and overall hospital stay to be less than open repair.  Many 
of the patients presenting with a thoracoabdominal aneurysm are not candidates for open repair due to 
existing comorbidities.  With the progressive nature of the disease, these patients have limited options 
for medical intervention and are willing to assume a higher amount of risk.   
Patients who have a planned staged procedure may benefit from reduced SCI events, contrast 
exposure, fluids, procedure time, and less overall insult to their pulmonary status. We expect the 
amount of discomfort, total blood loss, recovery time, and overall hospital stay to be similar to an 
unstaged repair.  These subjects would be placed at increased risks related to a second procedure 
including those identified in the risk analysis.  With the progressive nature of the disease, these patients 
have limited options for medical intervention and may be willing to assume a higher amount of risk.   
3.8 Report of Prior Investigations Synopsis 
The outcomes from prior clinical evaluation of the study device, including successfully treating 
99% (84/85) of the intended target vessels and 96% (27/28) limb patency observed at one year, 
demonstrate the potential benefits of the device.  When contrasted with open repair’s significant 

 
 
 
Page 49 of 103 
 
complication rates and branch fenestrated device’s significant anatomic and logistic limitations, the 
potential risk of the proposed novel graft does not outweigh the potential benefit of widened anatomic 
availability and improved patency rates.  Given the potential benefits, we feel that it is justified to 
expose the target patient population to the potential risk.  The non-clinical testing performed by 
Medtronic and the clinical results reported by Sanford Health show adequate safety of the device to 
support a clinical study.   

 
 
 
Page 50 of 103 
 
4. Investigation Plan 
4.1 Purpose 
The primary objective of the clinical investigation is to assess the use of the VTAAA stent graft 
system to repair thoracoabdominal aortic aneurysms in patients having appropriate anatomy. The 
primary intent of the study is to assess safety (i.e. freedom from major adverse events (MAE) at 30 
days) and preliminary effectiveness (i.e., treatment success and technical success) of the device (i.e., 
the proportion of treatment group subjects that achieve and maintain treatment success at one year).   
Additionally, the study will assess technical success and treatment success at each follow-up 
interval. 
4.2 Intended Use 
The VTAAA stent graft system is indicated for the endovascular treatment of thoracoabdominal 
aortic aneurysm (Crawford Type 1, 2, 3 and 5) in patients with the following characteristics: 
• An aneurysm with a maximum diameter of > 5.5 cm or 2 times the normal diameter just 
proximal to the aneurysm using orthogonal (i.e., perpendicular to the centerline) 
measurements.  
• Aneurysm with a history of growth greater than or equal to 0.5 cm in 6 months.   
• Saccular aneurysm deemed at significant risk for rupture 
• Symptomatic aneurysm greater than or equal to 4.5 cm 
• Axillary or brachial and iliac or femoral access vessel morphology that is compatible 
with vascular access techniques, devices or accessories, with or without use of a surgical 
conduit 
• Proximal landing zone for the thoracic bifurcation stent graft that has: 

 
 
 
Page 51 of 103 
 
greater than or equal to 2.5 cm of non-aneurysmal aortic segment including 
previously placed graft material (neck) distal to the left subclavian artery 
(LSA) and diameter in the range of 26-42 mm 
o Adequate distance from the celiac artery, in order to accommodate cannulation 
from the antegrade access point when considering the total deployed length of 
the thoracic bifurcation and visceral manifold 
• Iliac artery or aortic distal fixation site, including both native tissue and previously 
placed graft, greater than or equal to 15 mm in length and diameter in the range of 8 – 25 
mm 
• Age: greater than or equal to 18 years old 
• Life expectancy: greater than 1 year 
4.3 Device Description 
The VTAAA stent graft system is made up of two main body components and makes use of 
several off-the-shelf FDA-approved stent graft components.  The two custom main body grafts are the 
thoracic bifurcation (Figure 1A) and the visceral manifold (Figure 1B).  The thoracic bifurcation is 
deployed in the thoracic aorta and provides the proximal seal for the device.  For a Type I or II 
thoracoabdominal aneurysm the proximal seal is in zone 3 and for Type III and V the device seals in 
zone 4.  The smaller 16 mm limb of the thoracic bifurcation extends to the infrarenal segment to either 
seal in zone 9 for a Type I and V and in zone 10 for Type II and III. The two limbs of the thoracic 
bifurcation allow for continued aortic flow while deploying the visceral segment.  The visceral 
manifold is deployed within the larger 20 mm limb of the thoracic bifurcation to set the stage for the 
visceral debranching.  The branches of the visceral manifold extend to the visceral vessel with the use 
of covered bridging stents and provide distal seal of the manifold.   The smaller 16 mm limb of the 

 
 
 
Page 52 of 103 
 
thoracic bifurcation extends to the infrarenal segment to either seal in zone 9 for a Type I and V and in 
zone 10 for Type II and III.  All other connections in the device make use of sizes that are modular and 
independent of patient anatomy. 
 
 
 
A 
B 
Figure 3: Images of the manufactured device A) the thoracic bifurcation main 
body graft and B) visceral manifold main body graft 
 
4.4 Protocol 
This study is a prospective, single-center, non-randomized, single-arm study to evaluate the 
therapeutic benefit of the VTAAA stent graft system .  A total of 15 patients will be enrolled in the 
study (8 patients to be enrolled in primary arm, 7 to be enrolled in expanded arm).  The duration of the 
Investigation is anticipated as follows: 
• Time to Complete Enrollment: 24 months 
• Subject Follow-up Time: 5 years from last subject enrollment 
• Total Duration Time: 7 years 

 
 
 
Page 53 of 103 
 
4.4.1 Description of the Patient Population 
The study will evaluate 15 patients (8 patients to be enrolled in primary arm, 7 to be enrolled in 
expanded arm) with type 1, 2, 3 and 5 thoracoabdominal aneurysms meeting protocol inclusion criteria.  
The patient population includes both male and female patients greater than 18 years old with a life 
expectancy of at least one year.   
4.4.2 Eligibility Criteria 
Primary Study Arm 
Inclusion Criteria 
• A patient may be entered into the study if the patient has at least one of the following: 
o An aneurysm with a maximum diameter of greater than or equal to 5.5 cm or 2 times 
the normal diameter just proximal to the aneurysm using orthogonal (i.e., 
perpendicular to the centerline) measurements 
o Aneurysm with a history of growth greater than or equal to  0.5 cm in 6 months  
o Saccular aneurysm deemed at significant risk for rupture 
o Symptomatic aneurysm greater than or equal to 4.5 cm 
• Axillary or brachial and iliac or femoral access vessel morphology that is compatible with 
vascular access techniques, devices or accessories, with or without use of a surgical conduit 
• Proximal landing zone for the thoracic bifurcation stent graft that has: 
o Greater than or equal to 2.5 cm of non-aneurysmal aortic segment including previously 
placed graft material (neck) distal to the left subclavian artery (LSA) and diameter in the 
range of 26-42 mm 
 

 
 
 
Page 54 of 103 
 
o Adequate distance from the celiac artery, in order to accommodate cannulation from the 
antegrade access point when considering the total deployed length of the thoracic 
bifurcation and visceral manifold 
• Iliac artery or aortic distal fixation site, including both native tissue and previously placed 
graft, greater than or equal to 15 mm in length and diameter in the range of 8 – 25 mm 
• Age: greater than or equal to18 years old 
• Life expectancy: greater than  1 year 
Exclusion Criteria 
General exclusion 
• Patient is a good candidate for and elects for open surgical repair 
• Can be treated in accordance with the instructions for use with a legally marketed 
endovascular device  
• Is eligible for enrollment in a manufacturer-sponsored IDE at the investigational site 
• Unwilling to comply with the follow-up schedule 
• Inability or refusal to give informed consent  
• Urgent or emergent presentation 
 
• Patient is pregnant or breastfeeding 
• Patient has a contained rupture 
• Patient has a ruptured aneurysm 
• Patient has a dissection in the portion of the aorta intended to be treated 
• Obstructive stenting of any or all of the visceral vessels 

 
 
 
Page 55 of 103 
 
• 
Poor performance status including two major system failures (including but not limited 
to cardiovascular, pulmonary, renal, hepatobiliary, and neuromuscular) 
Medical exclusion criteria 
• Known sensitivities or allergies to the materials of construction of the devices, including 
nitinol (Nickel: Titanium), polyester, platinum-iridium, polytetrafluoroethylene (PTFE), 
platinum, gold, polyethylene, or stainless steel.   
• Known hypersensitivity or contraindication to anticoagulation or contrast media that 
cannot be adequately medically managed  
• Uncorrectable coagulopathy 
• Body habitus that would inhibit x-ray visualization of the aorta or exceeds the safe 
capacity of the equipment 
• Patient has had a major surgical or interventional procedure unrelated to the treatment of 
the aneurysm planned less than 30 days of the endovascular repair 
• Unstable angina (defined as angina with a progressive increase in symptoms, new onset 
at rest or nocturnal angina) 
• Systemic or local infection that may increase the risk of endovascular graft infection 
• Baseline creatinine greater than 2.0 mg/dL  
• History of connective tissue disorders (e.g., Marfan Syndrome in the primary arm only, 
not applicable for patients in the the expanded access arm, Ehler’s Danlos Syndrome) 
• Prior aneurysm repair that would involve relining of the previously placed graft material 
requiring placement of the investigational system in a landing zone that expands beyond 
any limits of the previously placed graft material 

 
 
 
Page 56 of 103 
 
Anatomical exclusion criteria 
• Minimum branch vessel diameter less than 5 mm 
• Thrombus or excessive calcification in the proximal aortic neck 
• Anatomy that would not allow maintenance of at least one patent hypogastric artery  
• Anatomy that would not allow primary or assisted patency of the left subclavian artery  
Expanded Selection criteria 
Subjects who fail to meet inclusion criteria for the primary study arm may be enrolled under an 
expanded selection arm if they meet the following criteria. 
Inclusion Criteria 
• Patient that meets the criteria for inclusion in the primary study arm but has one or more 
of the following criteria which would exclude them from the primary study arm: 
o Minimum Branch vessel diameter less than 5mm 
o Urgent or emergent presentation 
o Patient has a contained rupture 
o Patient has a ruptured aneurysm  
o Patient has a type B dissection (subacute or chronic) in the portion of the 
aorta intended to be treated 
o Poor performance status including two major system failures (including but 
not limited to cardiovascular, pulmonary, renal, hepatobiliary, and 
neuromuscular) 
o Baseline creatinine greater than or equal to 2.0 mg/dL 

 
 
 
Page 57 of 103 
 
o Anatomy that would not allow for maintenance of at least one hypogastric 
artery 
o Anatomy that would not allow for primary or assisted patency of the left 
subclavian artery 
o Prior aneurysm repair that would involve relining of the previously placed 
graft material requiring placement of the investigational system in a landing 
zone that expands beyond any limits of the previously placed graft material 
o Obstructive stenting of any or all of the visceral vessels 
Or 
• Patient that meets the criteria for inclusion in the primary study arm and:  
o Would not be eligible for the primary study arm per a documented reason 
other than those outlined above, and 
o Per the opinion of the Principal Investigator, with concurrence of the IRB, 
alternative therapies are unsatisfactory and the probable risk of using the 
investigational device is no greater than the probable risk from the disease or 
condition. 
o Patients with Marfan Syndrome previously treated with proximal thoracic 
aortic graft able to be treated with Valiant TAA without reliance on graft 
seal to Marfan aorta 
4.4.3 Study Endpoints 
The primary safety endpoint is freedom from major adverse events (MAE) at 30 days or during 
hospitalization if this exceeds 30 days.   

 
 
 
Page 58 of 103 
 
Major adverse events include death, bowel ischemia, myocardial infarction, paraplegia, renal 
failure, respiratory failure, and stroke. 
The primary effectiveness endpoint is the proportion of the study subjects with treatment 
success at 1 year.  Treatment success is defined as a composite of technical success and freedom from 
the following:  
• Aneurysm enlargement i.e., greater than5mm as compared to any previous CT 
measure using orthogonal (i.e., perpendicular to the centerline) measurements 
• Aneurysm rupture 
• Aneurysm-related mortality 
• Conversion to open repair  
• Secondary intervention for migration, Type I and III endoleaks, device integrity failure 
(e.g., fracture), and patency-related events (i.e., device component stenosis or 
occlusion and embolic events) 
Secondary endpoints include: 
• Technical success and the individual components of technical success:  
o Successful delivery 
o Deployment at the intended implantation site 
o Patency of all endovascular graft and stent components 
o Absence of device deformations requiring unplanned placement of an 
additional device  
o Absence of inadvertent covering of aortic branch vessels 
o Successful withdrawal  

 
 
 
Page 59 of 103 
 
• Freedom from the individual components of the primary safety endpoint at 30 days: 
o Death 
o Bowel ischemia 
o Myocardial infarction 
o Paraplegia 
o Renal failure 
o Respiratory failure 
o Stroke 
• Freedom from paraparesis at 30 days 
• The following at each follow-up interval: 
o Treatment success and the individual components of treatment success 
including freedom from the following:  
- Aneurysm enlargement  
- Aneurysm-related mortality  
- Aneurysm rupture 
- Conversion to open repair 
- Secondary intervention for migration, type I and III endoleaks, device 
integrity failure (i.e., fracture), and patency-related events (i.e., device 
stenosis or occlusion and embolic events).  
- Renal failure 
- All-cause mortality 
- Endoleaks 
- Device integrity failure (e.g., fracture) 

 
 
 
Page 60 of 103 
 
- Patency-related events (i.e., device stenosis or occlusion and embolic 
events) 
- Other device-related events 
4.4.4 Follow-up Schedule 
Patients included in the study will undergo follow-up at one month, six months, twelve months 
and then annually for five years.  In the event of patient death, an autopsy may be performed.   
Table 5. Follow-up Table  
 
Month 
 
Pre-
op 
Intra-op 
Index 
Pre- 
discharge 
Intra-op 
Completion 
(if staged) 
Pre- 
discharge  
(if staged) 
1 
6 
12 
24 
36 
48 
60 
CTA/CT with 
contrast of Chest, 
Abdomen, and 
Pelvis 
X2,3 
 
X1,2, 8 
 
X1,2, 8 
X1,2 
X1,2 
X1,2 
X1,2 
X1,2 
X1,2 
X1,2 
Angiography 
X3 
X 
 
 
 
 
 
 
 
 
 
 
Blood Tests 
X4 
X5, 6 
X4, 8 
X4,6 
X4, 8 
X4 
X4 
X4 
X4 
X4 
X4 
X4 
Clinical Exam 
(including ABI) 
 
X7 
 
 
X8 
 
 
 
X8 
 
X7 
 
X7 
 
X7 
 
X7 
 
X7 
 
X7 
 
X7 
Branch Patency 
(duplex ultrasound) 
 
 
 
 
 
 
X2 
 
X2 
 
X2 
 
X2 
 
X2 
 
X2 
 
X2 
1  Device X-ray may be requested to provide more focused imaging if potential device integrity issues are identified, but are unable to be 
confirmed, using CT. 
2   If renal function does not allow for CTA or CT with contrast, an alternative contrast-enhanced imaging modality or, at a minimum, non-
contrast CT in conjunction with duplex ultrasound may be used at physicians discretion.   
3   Pre-procedure angiography may be requested at discretion of film reviewer. 
4   Blood tests include CBC for hemoglobin and BMP for creatinine. 
5   Blood test for ACT. 
6   Other intra-op labs for anesthesia.   
7   Urine pregnancy test (for female patients of childbearing age). 
8   CT, Duplex, ABI and labs are optional at the pre-discharge and one month visits between staging procedures. 
 
 
4.4.5 Patient Enrollment and Screening 
The investigator will assess potential study subjects with thoracoabdominal aortic aneurysms 
for their suitability for enrollment into the clinical study.  If the patient appears to meet eligibility 

 
 
 
Page 61 of 103 
 
criteria, then the investigator or clinical study coordinator will discuss the study with the patient and 
provide patient education materials to adequately inform the patient of potential risks and benefits, 
required follow-up procedures, and answer any questions.  The clinical study coordinator will facilitate 
the informed consent process.  After the patient has been properly consented, the patient will complete 
additional screening procedures that need to be completed.  If the patient does not sign the informed 
consent, they will not be enrolled in the study.  Information to be collected for screening include: 
o Patient demographics 
o Medical history 
o Current health status 
o Physical examination 
o Ankle Brachial Index (ABI) 
o Pregnancy test (for female patients of childbearing age) 
o An X-Ray may be performed per local standard of care.  A/P, Lateral and Bilateral 
Oblique Images will be obtained. 
o CTA or CT with contrast of the chest, abdomen and pelvis if renal function allows.  If 
renal function does not allow CT with contrast, an alternative contrast-enhanced 
imaging modality or, at a minimum, CT non-contrast in conjunction with Duplex 
ultrasound will be used at physician discretion to evaluate: 
• Access vessels for compatibility with vascular access techniques 
• Obstructive stenting of the visceral vessels 
•  Vessels diameters suitable for use with the VTAAA stent graft system  
• Aneurysm rupture 
• Branch stenosis of the SMA, celiac, left and right renal arteries  

 
 
 
Page 62 of 103 
 
• Dissection 
• Patency of left subclavian artery, hypogastric arteries, lumbar arteries, and all 
four visceral vessels 
• Thrombus or excessive calcification in the neck of the aneurysm 
• Presence and location of any previously placed graft material 
o Complete blood count to evaluate white blood cells, hemoglobin, and platelets 
o Basic metabolic panel to evaluate creatinine 
o Pulmonary function test (for patients with a history of smoking or if deemed necessary 
by the PI)  
o Cardiac clearance 
4.4.5.1 Case Planning 
From the pre-op CT, the surgeon will make the following measurements to size the endografts. 
1. Length of the proximal seal zone, the distance required to land the thoracic bifurcation stent 
graft, this requires greater than or equal to  2.5 cm section of healthy aorta, distal to the left 
subclavian artery.   
2. Diameter of the proximal landing zone to define the required diameter of the thoracic 
bifurcation stent graft.  The diameter of the thoracic bifurcation stent graft should be 10-
15% larger than the diameter of the aorta to proper oversize the stent graft.   
3. Maximum aortic diameter within the treated aorta  
4. Distance from the top of the celiac to the top of the most cephalic renal.   
5. Distance from the top of the proximal seal zone to the takeoff of the celiac.   
6. Distance from the top of the celiac to the SMA.   
7. Angulation at the mid-thoracic aorta. 

 
 
 
Page 63 of 103 
 
8. Angulation at the diaphragm. 
9. Angulation at the renal arteries. 
10. Distance from the right renal to the ipsilateral internal iliac artery. 
11. Distance from lower renals to aortic bifurcation.    
12. Diameter of the branch vessels (celiac, SMA, left renal, and right renal) to determine the 
diameter bridging stents needed and percent patency.   
13. Diameter of the right and left common iliac to secure the distal seal of the infrarenal 
bifurcation.   
14. Diameter of the distal aorta to secure the distal seal in the aorta 
15. Length between distal edge of LSA and start of aneurysm 
16. Length of proximal seal zone 
17. Length of aneurysm 
18. Minimum diameter of the access sites (right and left femoral and brachial access site).   
19. Length from the access sites to the target treatment zone (right and left femoral and brachial 
access site).   
Note: If treating a dissection under the expanded selection arm the true and false lumen as well as 
any naturally occurring fenestrations will be evaluated to determine placement of the device and 
which lumen feeds the branch vessels.   
Note: If treating a patient with previously placed graft material, either proximally or distally, it 
must be determined if the landing zones will be within the previously placed graft material or if  the 
landing zones extend beyond the limits of the previously placed graft material.  
 
 

 
 
 
Page 64 of 103 
 
4.4.5.2 Pre-operative procedures 
The patient will be removed from anti-coagulants prior to surgery.  The day of surgery the 
following labs will be taken: 
o Complete blood count to evaluate white blood cells, hemoglobin, and platelets 
o Basic metabolic panel to evaluate creatinine 
o Prothrombin time (at physician discretion) 
o Partial thromboplastin time (at physician discretion) 
o Pregnancy test (for female patients of childbearing age) 
Spinal Drain 
o The use of a spinal drain is required for all non-staged procedures on subjects being 
treated for a Crawford Type I, II, III, or V thoracoabdominal aneurysm 
o In the case of prior spinal surgery or any reason that would put the patient at 
higher risk for complications, the use is at the physician’s discretion 
o The use of a spinal drain on staged procedures is at the physician’s discretion 
The patient will be treated with general anesthesia under standard medical practices along with 
placement of a lumbar drain when possible.  The management of anesthesia and the lumbar drain will 
be performed by the staffed anesthesia team.  Standard heparinization practices will be followed and 
active clotting time will be monitored throughout the procedure.  The patient will be prepped in normal 
sterile fashion from the clavicle to mid-thigh.  Additionally, contrast will be diluted 50/50 in saline to 
reduce contrast exposure.  Radiation reduction procedures will be followed as allowed.   
4.4.5.3 Implant Procedures 

 
 
 
Page 65 of 103 
 
Note: The design of the VTAAA stent graft system is modular in nature and allows for bailouts 
and staging of the procedure following the deployment of each device.  The procedure can be stopped 
at the completion of deployment of each component of the system and the patient has the opportunity 
for alternate endovascular, open repair techniques, or completion of the procedure at a later date if 
such conditions arise.   
A. The implantation of the VTAAA stent graft system is conducted under 
fluoroscopic/angiographic guidance.  Refer to the VTAAA stent graft system Instructions for 
Use (IFU) for techniques and methods for device deployment and implantation.   
B. The VTAAA stent graft system may be implanted in a staged procedure per physician discretion 
(in either a planned or bail-out fashion).  The physician may choose to perform the procedure in 
two or more stages due to the following conditions/scenarios including but not limited to: 
hypogastric patency, LSA patency, visceral vessel patency, decreased MEP/SEP potentials, at 
risk dominant segmental arteries, pulmonary status, or any patient whose physiologic 
limitations places them at risk because of the expected length of surgery. The preferred method 
for planned staging is to create a controlled endoleak which provides limited and temporary 
perfusion to the aneurysm sac.  These methods include but are not limited to placing a bare 
metal stent in the celiac artery bridge, placing a bare metal stent in the bridge to an alternate 
visceral artery (ie: SMA or renal), or not completing distal seal in the aorta or iliac arteries.      
a. Thoracic Graft Placement 
i. This refers to implanting stent-grafts into the thoracic aorta prior to enrollment 
into the IDE clinical study.  
ii. Device Visualization and Preparation 
Refer to the Instructions for use provided for the thoracic components to be used.   

 
 
 
Page 66 of 103 
 
iii. Device Placement 
Ensure that the distal edge of the thoracic graft is 5-7 cm proximal to the celiac 
artery. 
iv. Thoracic Aorta Component Deployment 
Follow the study protocol or IFU for deploying the thoracic graft components. 
v. Completion  
The date of the index procedure will be targeted for within 6 weeks of the 
thoracic graft placement, but will be based on physician discretion, clinical 
presentation, and patient compliance.   
b. Planned Staged Procedure: Visceral artery bridge endoleak 
i. This refers to leaving open a portion of the covered stent bridge between the 
visceral manifold and target vessel. This is achieved by combining bare metal 
stents with covered stents to leave ~1-2cm of uncovered conduit along the 
pathway. This intentional endoleak is resolved in a subsequent intervention 
where the open portion is covered over by an additional covered stent. It is 
preferable to achieve this configuration with the bridge to the celiac artery but it 
can be done in analogous fashion with either the SMA or renal arteries.  
ii. Device Visualization and Preparation 
Refer to the Instructions for use provided for the bare metal stent for 
visualization and preparation instruction.  
iii. Bridging Stent Deployment 
Follow directions in the IFU when deploying bridging stents. Always deploy a 
covered stent in the leg of the visceral manifold per the VTAAA stent graft 

 
 
 
Page 67 of 103 
 
system IFU. When possible, covered stents should be used in the target vessel. 
The chain of covered stents should be non-continuous in nature with at least one 
bare metal balloon expandable stent connecting them. The segment of 
completely bare stent should be short (~1-2cm) with 2-3cm overlapping with 
covered stent on either side. Creation of the uncovered segment in as straight of 
configuration as the anatomy allows will facilitate wire passage during the 
completion procedure below.   
Note: The controlled endoleak should never be created by leaving a visceral 
manifold limb unconnected to a visceral vessel or with an uncovered segment 
>2cm due to the pressurization of the aneurysm sac.  If a visceral vessel is 
occluded, the corresponding visceral manifold limb should be plugged with a 
vascular plug and an alternative (patent) vessel utilized for the staging 
procedure.  The placement of the non-continuous chain of covered bringing 
stents and a bare metal stent helps direct flow while creating a controlled 
endoleak.   
iv. Completion  
Completion of the staged procedure is targeted for 4-6 weeks following the index 
procedure, but will be based on physician discretion, clinical presentation, and 
patient compliance.   
Note: The physician may choose to complete the procedure earlier if the patient 
is symptomatic or has other concerns for aneurysm sac growth or rupture.   
Completion procedure may be performed under local or general anesthesia.  
Vascular access will be established in the brachial or axillary artery. The staged 

 
 
 
Page 68 of 103 
 
limb of the visceral manifold will be cannulated, and the bare segment will be 
covered over by at least one iCAST or VBX.  
c. Planned Stage Procedure: Delayed distal seal 
i. This refers to completing the visceral debranching (manifold to target arteries) 
with covered stents and subsequently leaving out one or more of the distal 
aortic/iliac components.  
ii. Device Visualization and Preparation 
Refer to the Instructions for use provided for the distal aortic/iliac components to 
be used.   
iii. Distal Aortic/Iliac Component Deployment 
Follow the study protocol or IFU for deploying the distal aortic/iliac 
components.   
iv. Completion  
Completion of the staged procedure is targeted for 4-6 weeks following the index 
procedure, but will be based on physician discretion, clinical presentation, and 
patient compliance.   
Note: The physician may choose to complete the procedure earlier if the patient 
is symptomatic or has other concerns for aneurysm sac growth or rupture.   
Completion procedure may be performed under local or general anesthesia.   
d. Bail-out Stage Procedure 
i. A bail-out method may be used for staging in the event patient status declines 
during the case or inability to technically complete the case.   
ii. Device Visualization and Preparation 

 
 
 
Page 69 of 103 
 
Refer to the Instructions for use provided for the components to be used.   
iii. Device Deployment 
Refer to the Valiant Thoracoabdominal Stent Graft System (IFU) for device 
deployment and implantation of the remaining components.   
iv. Completion due to patient status decline 
Completion of a bail-out staged procedure due to patient status should be 
completed as soon as clinically feasible following the index procedure, but will be 
based on physician discretion, clinical presentation, and patient compliance.   
Note: The physician may choose to delay staging if the patient has complications 
or there are concerns with completing the secondary procedure.   
v. Completion due to inability to technically complete the case 
Completion of a bail-out procedure due to technical challenges have the 
following options that present no more risk than the alternative of no treatment.   
a. Complete case at another date 
b. Medical management 
c. Convert to open surgical repair 
d. Referral to another facility/investigator that can complete the 
procedure 
C.  
• Note:  If treating a dissected aorta, naturally occurring fenestrations will be utilized 
first, and if necessary, there may be the additional use of an excimer laser or perforating 

 
 
 
Page 70 of 103 
 
needle and catheter to perforate the intimal membrane.  This perforation will be used to 
enter either the false or true lumen in order to accommodate placement of the device. 
• Note:  Caution should be taken when relining previously placed graft material to 
prevent complications from graft on graft friction including decreased graft 
maneuverability and challenges repositioning. 
• Note: For proximal extension of the thoracic bifurcation, two Valiant Captivia or 
Valiant Navion thoracic grafts can be used.  One to extend the landing zone more 
proximally and one to layer to prevent wear. Deploy the Valiant Captiva or Valiant 
Navion thoracic grafts according to their respective manufacturer’s IFU and  continue 
according to the VTAAA stent graft system IFU. 
• Note: For type 1and 5 aneurysms the distal end of visceral bypass (VB) should be sized 
to provide the distal seal with the aorta and then proceed to Step 4.4.5.5, Completion 
Procedures.   
• Note: If the VB is too short or too small to provide distal seal, a Valiant Captiviastent 
graft or Endurant Limb may be used in place or in conjunction with the Visceral Bypass 
to provide adequate distal seal.  For type 2 and 3 proceed to deployment of the 
infrarenal bifurcation and Endurant II limb stent graft instructions in the VTAAA stent 
graft system IFU. If a commercially available Endurant limb or Valiant stent graft is 
used as the Visceral Bypass a commercially available Endurant mainbody stent graft 
with suprarenal fixation and a Gore cuff is required for adequate fixation.  See Step 
1.4.5.5.3.C and Step 1.4.5.5.4.D. below for deployment procedures. 
• Note: if treating a subject with an occluded visceral vessel, a vascular plug may be used 
to occlude the extra limb of the Visceral Manifold stent graft. 

 
 
 
Page 71 of 103 
 
 
B. Surgical Decision Pathway and Bailouts
 
Figure 4: Surgical decision path and possible bailouts  
C.  Visceral Bypass (VB) Instructions (Endurant Long Limb) 
1. Insert a guidewire from the groin through the 16-mm limb of the thoracic bifurcation. 
2. Refer to the manufacturer’s IFU (Endurant) for visualization and preparation instructions.   
3. The proximal radiopaque marker of the VB stent graft should be aligned with the bifurcation of 
the thoracic bifurcation.   

 
 
 
Page 72 of 103 
 
4. Verify there is a 5 cm overlap with the 16 mm leg of the thoracic bifurcation.  
5. Deploy the VB according to the manufacturer’s IFU (Endurant).   
6. Leave the guidewire in place and remove the delivery system according the to manufacturer’s 
IFU (Endurant).   
D. Infrarenal Bifurcation (IB) Instructions (Endurant Mainbody)  
1. Refer to the manufacturer’s IFU (Endurant) for visualization and preparation instructions.   
2. Identify the guidewire that passes through the VB stent graft.  
3. From the ipsilateral groin access point, insert the delivery system over the guidewire.   
4. Slowly advance the bifurcated graft into the VB stent graft. 
5. Verify there is a 4-5cm overlap with the VB stent graft.  
6. Confirm the distal portion of the contralateral leg is above the aortic bifurcation.   
7. Confirm the radiopaque ring marker on the distal end of the contralateral leg is in a position to 
allow for cannulation from the contralateral iliac artery.   
8. Confirm the distal target landing zone relative to anatomical landmarks (i.e. internal iliac artery).   
9. Deploy the bifurcated graft according to the manufacturer’s IFU (Endurant).   
10. Release the tip capture mechanism according to the manufacturer’s IFU (Endurant).   
11. Remove the delivery system according the to manufacturer’s IFU (Endurant).   

 
 
 
Page 73 of 103 
 
12. Complete distal seal of the bifurcated graft into the common iliacs according the manufacturer’s 
IFU (Endurant).   
13. If the Endurant mainbody with suprarenal fixation is used deploy a Gore Aortic Extender 
Endoprosthesis according to the manufacturer’s IFU (Gore Excluder) over the suprarenal 
fixation stent of the bifurcated graft (Endurant mainbody) to seal and prevent endoleaks in the 
event the suprarenal fixation stent were to puncture the graft material.   
4.4.5.4 Completion Procedures 
1. At the physician’s discretion, line the bridging stent grafts with self-expanding bare metal 
stent(s) to provide additional radial support.  Note: In the event a bridging stent or self-
expanding stent needs reinforcement a Viabahn stent graft of appropriate sizing may be 
used.   
2. Begin to optimize spinal perfusion.   
3. After deployment of all stent grafts, all contact points will be balloon angioplasties.   
4. Perform an angiogram to verify stent graft apposition, seals, patency, device defects and any 
endoleaks.  Perform additional procedures, such as ballooning, cuff placement, or use of 
covered stent grafts as necessary to treat endoleaks or device failures. Perform any adjunct 
procedures including but not limited to ballooning, atherectomy, or placement of stents to repair 
or treat any arterial issues or concomitant disease process in the iliac system to maintain flow to 
the lower extremities or the upper access arm extremity.    
5. Remove all sheaths, wires, and remaining accessories and repair of arterial access sites using 
standard surgical closure techniques. 

 
 
 
Page 74 of 103 
 
6.  Dopperable signals will be confirmed in bilateral lower extremities and the access upper 
extremities.  
7. Once adequate perfusion is confirmed, heparinization will be reversed. 
8.  In the event of patient death an autopsy may be performed.     
4.4.5.5 Post-operative Care 
All patients may remain intubated and be transferred to the ICU standard post-operative care.  
Patients with a spinal drain will remain in bed with optimization of spinal perfusion pressure for 24-72 
hours whenever possible.  Post-operative care will be tailored to the patient taking into account events 
of surgery as well as pre-operative comorbidities to optimize the patient’s recovery.  On post-operative 
day two, attempts will be made to normalize the MAP and clamp the spinal drain if used.  Prior to 
spinal drain removal all coagulopathies and low platelet counts are corrected.  The patient’s 
neurological status is closely watched for the next 4-6 hours.  If it remains stable, the drain is removed, 
and the patient is monitored for hypoxia, anemia, and hypotension.  In the event of patient death an 
autopsy may be performed.  Prior to discharge from the hospital, the following tests will be performed:  
o 
Physical examination 
o 
Complete blood count to evaluate white blood cells, hemoglobin, and platelets 
o 
Basic metabolic panel to evaluate creatinine 
o 
Prothrombin time (at physician discretion) 
o 
Partial thromboplastin time (at physician discretion) 
o 
CTA or CT with contrast of the chest, abdomen and pelvis if renal function allows.  If 
renal function does not allow CT with contrast, an alternative contrast-enhanced 
imaging modality or, at a minimum, CT non-contrast in conjunction with Duplex 
ultrasound will be used at physician discretion. 

 
 
 
Page 75 of 103 
 
 
 

 
 
 
Page 76 of 103 
 
4.4.5.6 Follow-up Visits 
 
All patients will undergo follow-up at one month, six months, twelve months and then annually 
for five years (as described in Section 4.4.4).  At each of the follow-up visits the following tests will be 
performed:  
o 
Physical examination  
o 
Complete blood count to evaluate white blood cells, hemoglobin, and platelets 
o 
Basic metabolic panel to evaluate creatinine 
o 
CTA or CT with contrast of the chest, abdomen and pelvis if renal function allows.  If 
renal function does not allow CT with contrast, an alternative contrast-enhanced 
imaging modality or, at a minimum, CT non-contrast in conjunction with Duplex 
ultrasound will be used at physician discretion. 
o 
An X-Ray may be performed at each follow-up visit in conjunction with the CTA per 
local standard of care.  A/P, Lateral and Bilateral Oblique Images will be obtained. 
4.4.6 Sample Size Justification 
The sample size for the feasibility study is limited to 15 (8 patients for the primary study arm 
and 7 patients for the expanded selection arm), as this is adequate to provide preliminary clinical safety 
data and effectiveness of the device.  The device, while novel, has been evaluated in a clinical setting 
and has initially demonstrated both safety and effectiveness.  The limited sample size allows adequate 
patient data to be collected under a controlled protocol without exposing a large patient population to 
the risk associated with a novel device design.  The safety and effectiveness data collected in this study 
will be pooled with other physician sponsored investigational device exemptions (PS-IDEs) evaluating 
the VTAAA stent graft system and should be sufficient to develop an appropriate pivotal study.   

 
 
 
Page 77 of 103 
 
4.4.7 Data Presentation and Analysis Plan 
The primary purpose of this study is to evaluate the safety of this device as there are no or very 
limited devices and clinical options available for this patient population.  The primary safety endpoint 
of this study is safety freedom from major adverse events (MAE) at 30 days or during hospitalization if 
this exceeds 30 days.  Major adverse events include death, bowel ischemia, myocardial infarction, 
paraplegia, renal failure, respiratory failure, and stroke.  The primary safety endpoint will be analyzed 
to determine statistical significance when compared to a target performance goal.  A literature review 
of outcomes of open surgical repair was used to create the performance goal as there is not a 
comparable endovascular option to use for analysis.  The performance goal was selected based on the 
range of subjects experiencing a major adverse event at 30 days.  The range was calculated based on 
assumptions of the minimum and maximum number of subjects experiencing at least one MAE in the 
historical open surgical repair group (Table 6).  Based on the literature reviewed and the above 
assumptions the range of subjects experiencing at least one MAE in the open surgical repair group is 
30.5% to 77.4%.   
The primary effectiveness endpoint is the proportion of the study subjects with treatment 
success at 1 year.  The data will be presented as quality outcomes with the number of study subjects 
with treatment success compared to the overall patient population.    
Additionally, data outcomes from this study will be entered into a common vascular database so 
that data can be pooled with other PS-IDEs.  This would provide consistent reporting across the PS-
IDEs.  Additionally, the PS-IDEs will be evaluating the same device and endpoints to allow for a pool-
ability of data across the sites.   

 
 
 
Page 78 of 103 
 
The pooled data will be separated into two separate study arms: primary study arm and 
expanded selection arm. 
4.4.7.1 Statistical Methods 
The primary hypothesis of the Visceral Manifold Study is the number of subjects experiencing a 
major adverse event through 30 days will be less than a target performance goal (PG) of 50%. The PG 
was determined by using a conservative target that is approximately the average of the open surgical 
repair MAE rate calculated above (30.5%-77.4%, Table 6).  The anticipated test device 30-day MAE 
rate was based on the current rate of MAE’s (26%, Table 7) observed in 20 subjects meeting inclusion 
criteria into the primary study as of June 2016.   
The sample size for the Visceral Manifold Study was determined using an exact method based 
on a one-sided 2.5% significance level and an anticipated 26% investigational device 30-day major 
adverse event rate.  Based on these assumptions, a sample size from the pooled PS-IDE data of 46 
subjects provides at least 80% power to test the primary hypothesis.   
Table 6. Historical Comparison for Primary Safety Endpoint (MAE Rate at 30 days for Open 
Repair) 
Reference 
# of 
Patients 
Mortality 
Bowel 
Ischemia 
Myocardial 
Infarction 
Paraplegia 
Renal 
Failure 
Respiratory 
Failure 
Stroke 
Rigberg et al 
1010 
191 
(19%) 
 
 
 
 
 
 
Becquemin et 
al 
1678 
90 
(5.4%) 
51 (3%) 
20 (1.2%) 
16 (1%) 
289 (17.2%) 
124 (7.4%) 
12 
(0.7%) 
Murana et al 
542 
46 
(8.5%) 
 
 
22 (4.2%) 
 
 
 
Ferrer et al 
257 
16 
(6.2%) 
 
 
53 (20.8%) 
31 (12.3%) 
31 (12.3%) 
 
Bensley et al 
450 
45 (10%) 
 
10 (2.4%) 
 
48 (10.7%) 
202 (45.1%) 
9 
(2.2%) 
Nathan et al 
83 
6 (5.6%) 
 
 
 
 
 
 
Dayama et al 
682 
68 (10%) 
 
87 (12.9%) 
 
117 (17.2%) 
286 (42%) 
 

 
 
 
Page 79 of 103 
 
Ferrante et al 
200 
5 (2.5%) 
 
25 (12.8%) 
 
22 (11%) 
27 (13.8%) 
 
Tsilimparis et 
al 
1091 
58 
(5.4%) 
 
87 (8%) 
 
109 (10%) 
229 (21%) 
 
Piazza et al 
7833 
1331 
(17%) 
 
 
587 (7.5%) 
1488 (19%) 
2819 (36%) 
 
Total 
13826 
1855/138
26  
51/1678  
229/4101  
678/10310  
2104/12191  
3718/12191  
21/2128  
Rate of MAE 
at 30 Days for 
Open 
Surgical 
Repair 
 
13.4% 
3.0% 
5.6% 
6.6% 
17.3% 
30.5% 
1.0% 
Table 7. Historical Comparison for Expected Investigational Device 30 Day MAE Rate 
(Outcomes of subjects treated with the VTAAA stent graft system and meeting 
inclusion into the primary study as of June 2016) 
Dataset 
Mortality 
Bowel 
Ischemia 
Myocardial 
Infarction 
Paraplegia 
Renal 
Failure 
Respiratory 
Failure 
Stroke 
Subjects 
meeting VMS  
PS-IDE I/E 
criteria 
0/20 
(0%) 
0/20 
(0%) 
0/20 (0%) 
2/20 
(9.5%) 
1/20 
(5%) 
3/20 (14%) 
0/20 
(0%) 
 
4.4.8 Limitations of the Study 
Limitations of the study are that it is a single center study with a small patient population.  We 
aim to curb this limitation by pooling our data with other IDE holders.  
4.5 Risk Analysis  
The risk analysis includes a description and analysis of all increased risks to the research 
subjects and how these risks will be minimized. The risks can be separated into three categories: 
procedural-related risks, device performance-related risks, and device material-related risks.    
4.5.1 Potential Risks 
4.5.1.1 Procedural-related risks  
Procedural related risks including general and device specific procedural risks can result in 
several serious harms to the patient including contrast damage, allergic response, paraplegia, peripheral 

 
 
 
Page 80 of 103 
 
nerve damage, injury to access vessel, dislodging of thrombus, dissection or further dissection of vessel, 
rupture of a dissection, embolism, branch artery or parenchyma damage of ischemia, inadvertent internal 
iliac occlusion or ischemic colitis, radiation injury from the laser if used including redness or burns to 
the skin, system effects including increased risk of morbidity and mortality, local effects at the access 
site including wound infection, hematomas, seromas, arterial or venous damage, failure to access the 
aorta, inaccurate deployment of devices, failure to deploy devices, and displacement of devices.  These 
risks can be mitigated in a number of ways including strict adherence to the investigational protocol, 
patient eligibility criteria, procedures performed by trained and qualified physicians, use of standard 
surgical and endovascular techniques, and regular follow-ups.  Although the risk is lowered by 
following these mitigation strategies the risk cannot be completely eliminated.  However, the potential 
benefit of the manifold system as compared to other surgical techniques outweighs the potential 
procedural related risks to the patient.    
4.5.1.2 Material-related risks 
Material related risks are risks that are associated with physical components of the stent graft 
including risks related to stent breakage, branch vessel stent crush, barb fracture, fabric wear, 
biocompatibility, and sterility.  Risks of these components include vessel occlusion, embolism, 
component separation, migration, and infection.  These risks can be mitigated several ways including 
careful case planning for patient selection, device placement, proper sizing, use of compatible 
components, and regular follow-ups to identify early evidence of migration or separation.    
4.5.1.3 Performance related risks 
There are performance risks of the modular components succumbing to material fatigue 
resulting in component separation, endoleak or endotension, graft occlusion, kinking, or migration.  
These risks can be mitigated several ways including adhering to industry standard seal zone lengths, 

 
 
 
Page 81 of 103 
 
proper oversizing, lining branch stents with self-expanding stents, regular follow-ups to identify early 
evidence of migration or separation and allow for appropriate treatment, by the use of completion 
angiography coupled with cuffs, ballooning, or additional stent grafts if evidence of endoleak.    
4.5.1.4 Actual Risk Realized While the stent graft design is intuitive, there is a learning curve 
with respect to the procedural considerations, necessary site infrastructure and post-operative 
management of patients treated with an endovascular TAAA therapy.  During initial enrollment, actual 
risks observed include but were not limited to renal injury/failure, respiratory failure, paraplegia, and 
all-cause mortality.  Although these risks are considered anticipated, the events are serious in nature 
and thus warrant investigation and consideration of appropriate corrective and preventative actions.  
The exact cause of each event and sequela of events within a given subject are difficult to extrapolate; 
however, lessons were learned during the first four cases in this series.  
The target patient population of this study can represent challenges such as advanced age, 
presence of significant co-morbidities, and in some cases complex aortic anatomy.  Anatomical 
challenges may influence operative variables (i.e. procedure time, blood loss, fluoroscopy time, and 
contrast volume) which may further exacerbate baseline co-morbidities and impact post-operative 
outcomes.  The first four subjects treated under the study each presented baseline and operative 
challenges that may have affected outcome.  From these experiences, lessons were learned, and 
mitigation strategies aimed to reduce risks identified.   
With respect to the actual risks observed, several mitigation strategies will be implemented from 
patient selection, procedural considerations and site infrastructure perspectives.  Procedural complexity 
is amplified substantially by arch anatomy either from right upper extremity access or from a type III 
arch with left upper extremity access, limiting subject selection.  Parallax alterations are frequent and 

 
 
 
Page 82 of 103 
 
compulsatory in toggling between branch access and Endo bypass deployment to prevent excessive 
coverage of branch vessels.  Embolic risks from dislodging soft thrombus prevents selection of patients 
with suspected acute thrombus formation within the Visceral aorta.  Patients are routinely affected by 
pulmonary complication making emphasis on pulmonary reserve a valued aspect of patient’s selection.   
Procedural considerations and site infrastructure changes will also be implemented to mitigate 
the risk of paraplegia and renal injury/failure.    To address paraplegia, a standardized staging protocol 
will be used in subjects deemed high risk for spinal cord ischemia.  Also, at physician’s discretion, for 
anatomies with retrograde collateral circulation into the internal iliac arteries, the femoral sheath may 
be removed after deployment of the manifold to lighten the severity of ischemia.  Renal function can be 
negatively impacted by operative variables and volume loading during the procedure.  Furthermore, 
vessel anatomy and visualization can create a challenge during the procedure that can impact overall 
procedure time, contrast volume administered and increase risk of vessel injury.  A commercially 
available 3-dimensional overlay with CT image interface may help prevent such a problem in the 
future. This should allow definition of the ostium with any angle of the image intensifier and would 
allow easier branch cannulation but also assessment of depth of penetration with AP imaging prior to 
stent deployment. Additionally, CO2 may be used as an alternative to iodinated contrast material.  
Additional mitigation strategies implemented to improve patient safety include external 
reviewer assessment of pre-operative CT scans, use of a central DSMB consistent with other parallel 
PS-IDEs, and frequent sharing of lessons learned between PS-IDE Investigators regarding safety and 
effectiveness. 
 
 

 
 
 
Page 83 of 103 
 
4.5.2 Mitigation of Risks 
Significant care and thought has gone into designing the VTAAA stent graft system and 
investigational procedure for proper delivery and deployment of devices to minimize risks to patients to 
the greatest degree possible.  The design of the stent graft is bifurcated to provide flow to uninterrupted 
blood flow to the visceral and infrarenal segments during the repair process, negating the need for 
aortic clamping utilized in open repair.  Additionally, the design of the stent graft system is modular to 
allow for bailouts and staging of the procedure throughout device deployment.  At any point in the 
procedure, the patient still has the opportunity for alternative treatments such as open surgical repair or 
other endovascular techniques.   
All efforts will be made to minimize the identified risks including:  
• 
Investigator and study personnel training will be conducted to share information 
regarding the design of the VTAAA stent graft system, its application and clinical 
results 
• 
Minimum infrastructure requirements including but not limited to:  
o Dedicated staff for first 10 procedures with technical success: 
▪ At least 2 board certified operators (vascular surgeon, 
interventional radiologist or interventional cardiologist).  
Fewer operators contingent upon experience of extended, 
dedicated OR staff with protocol and procedure. 
▪ Dedicated technicians in OR (minimum of 2, prefer 3) 
▪ Dedicated lead scrub technician with advanced open and 
endovascular experience 

 
 
 
Page 84 of 103 
 
▪ Dedicated anesthesia team  
▪ Dedicated research coordinator to attend each case to 
ensure proper documentation of procedural data and 
events throughout the entire case 
o Case oversight, including in-person case proctoring and/or remote 
case support, will be provided for a minimum of the first 5 
procedures post resumed enrollment and will be maintained at 
least until FDA is in agreement that it can be lifted 
o Evaluation of CT overlay technology imaging systems  
o Dedicated ICU staff with extensive complex cardiovascular care 
experience post-operatively (Recommend: frequent serial labs and 
hourly neuro checks for the first 12 hours post-op) Availability of 
appropriate ancillary device inventory, checked prior to procedure 
• 
Adherence to eligibility criteria and screening procedures to ensure that 
appropriate patients are selected and enrolled. 
• 
External physician reviewer assessment based on preoperative CT scan. 
• 
Standardized staging protocol aligned across parallel PS-IDEs 
• 
Adherence to the investigation protocol and clinical methods for case planning, , 
and implantation will be followed.   
• 
Patients will be carefully monitored throughout the study period.  
• 
The investigator will evaluate the adverse events during the course of the study.   
• 
Safety and effectiveness will be shared with additional Investigators to increase 
understanding of device and potential adverse events 

 
 
 
Page 85 of 103 
 
• 
Independent DMC to evaluate subject health, device performance, and identify 
safety concerns regarding subject well-being 
4.6 Data Management  
4.6.1 Data Collection 
 
1. The site will be required to have a local coordinator who will oversee the completion of the 
case report forms and be responsible for entering the information into the web-based database. A web-
based database has been designed for the study, which will improve efficiency, lower cost of the study, 
and speed up publication of the results.  Use of drop-down selection lists will be incorporated to aid the 
speed, accuracy and consistency of data entry.  The database will be backed up regularly on multiple 
media, and backups stored in a fire-proof safe.   
 
2. Data collected will include patient demographics, medical history, current health status, 
physical examinations, Ankle Brachial Index, pregnancy test results, relevant vessel diameters for 
determining compatibility with the VTAAA stent graft system, all relevant lab values, and all other 
relevant data abstracted from procedure and follow-up notes. 
 
3.  All data will be entered into the web-based data entry forms.  Individual case report forms 
will be kept at each site as source documents, as well as applicable medical records, and will be stored 
in a locked office within a secure research facility. 
4.6.2 Data Monitoring 
 
1. Routine data monitoring will occur to ensure data validity. Monitoring will occur at the 
following intervals: prior to the start of the clinical trial, at initiation of the study (at first implant and 
shortly thereafter with more frequent and intensive monitoring at the beginning of the study), at 

 
 
 
Page 86 of 103 
 
quarterly or interim periods, and at the end of the study.  Data monitoring will be conducted in person 
or via fax and telephone and will be tracked in the web-based data capture system by the Data Monitor.   
 
2. Study monitoring and auditing will be performed by experienced and appropriately trained 
personnel appointed by the sponsor/investigator to ensure that the investigation is conducted in 
accordance with FDA IDE regulations. 
4.7 Reporting  
All reports to FDA will be identified as SI-IDE Reports: 
Deviations from the investigational plan:  The sponsor-investigator will notify the reviewing 
IRB and FDA of any deviation from the investigational plan to protect the life or physical well-
being of a subject in an emergency. The notice will be provided as soon as possible but no later 
than 5 working days after the emergency occurred. If the change or deviation may affect the 
scientific soundness of the investigational plan or the rights, safety or welfare of the subject, the 
sponsor will obtain prior IRB approval and also FDA approval for the deviation by submitting 
an IDE supplement. 
Unanticipated adverse device effects:  The sponsor-investigator will report the results of an 
evaluation of an unanticipated adverse device effect to FDA and all reviewing IRBs within 10 
working days after the sponsor-investigator first receives notice of the adverse effect. 
Withdrawal of IRB approval: The sponsor-investigator will notify FDA of the withdrawal of 
IRB approval of an investigation (or any part of an investigation) within 5 working days of 
receipt of the withdrawal of approval. 

 
 
 
Page 87 of 103 
 
Progress report or annual reports: The sponsor will provide progress reports to the reviewing 
IRB and to the FDA using the suggested format provided at: 
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/HowtoMarketYourDev
ice/InvestigationalDeviceExemptionIDE/ucm046717.htm#sugforforidefin 
To describe the follow-up compliance for the study, the sponsor will include the following 
table in the annual progress report:  
Table 8. Annual progress report 
 
 
# (%) 
Adequate imaging to assess the parameter*** 
# (%) 
Events occurring before next interval 
# (%) 
Visit 
Eligible 
for 
follow-
up* 
Subjects 
with data 
for that 
visit 
 
CT 
 
X-
ray 
Subjects 
with 
follow-up 
pending** 
Size 
Increase 
 
Endoleak 
 
Migration 
Fracture 
Death 
Conversion 
LTF 
Not 
due 
for 
next 
visit 
Operative 
 
 
  
N/A 
 
N/A 
 
 
 
 
 
 
 
30 day 
 
 
 
 
 
 
 
 
 
 
 
 
 
6 month 
 
 
 
 
 
 
 
 
 
 
 
 
 
1 year 
 
 
 
 
 
 
 
 
 
 
 
 
 
Additional 
years 
 
 
 
 
 
 
 
 
 
 
 
 
 
*Eligible for follow-up = previous eligible for follow-up – (previous death + conversion + LTF + not due). 
** Subjects still within follow-up window, but data not yet available. 
*** Not the number of subjects with these reported events; the number with adequate imaging, such as paired size 
data to evaluate aneurysm growth.   
 
The sponsor will report at intervals of every five patients treated in the primary study arm 
(upon ten days following the 30-day follow-up of the fifth patient). Additionally, the sponsor will 
report a progress report for each patient treated under the expanded selection arm (upon ten days 
following the 30-day follow-up).  These reports will include the following information:  
Basic information on the number of patients enrolled and treated and information on 
observed adverse events for any subgroups (e.g., device types, extents of disease, lesion 

 
 
 
Page 88 of 103 
 
types).   These interim progress reports are meant to be summaries and not complete 
progress reports.  Details will be captured in any adverse event reports and annual 
reports to the IDE. 
 
Table 9: Enrollment summary*           
 
column for each 
subgroup 
Total 
Enrolled 
 
Treated 
 
Awaiting treatment 
 
Withdrawn (state reason) 
 
* A subject is considered enrolled after the device enters the body.     
 
Summary 
For each subgroup of patients, a brief narrative description of the procedures completed 
to date (e.g., how many had devices implanted successfully), any need for additional 
interventions, and the outcomes of any additional interventions will be provided.    
 
Table 10: Treatment summary   
             
                                                 
Adverse Events 
 
Comments on the most commonly observed challenges or adverse events will be provided. 
The following table is an example of how adverse event numbers may be presented for each 
subgroup.  The list will include events observed in the study, not necessarily all that are listed in 
this example.  
 
 
Number of patients 
Procedural success 
Perioperative death 
One branch 
 
Two branches 
 
Three branches 
 
Four branches 
 
Total 
 
                      
1st 5 
2nd 5 
Additional 
groups 
All 
Aortic dissection 
 
 
 
 

 
 
 
Page 89 of 103 
 
Table 6: Adverse Events    
 
 
Study subjects who had multiple complications will be designated using symbols (#, *, 
+) or numbers. 
 
Lessons Learned 
The lessons learned from the beginning of the study (e.g., with respect to patient selection, 
methods to minimize adverse events) will be summarized.  Procedures proposed or 
implemented to mitigate any risks or challenges that were observed during the study will be 
discussed, as well as any changes in outcomes based on experienced gained during the study. 
Recalls and device dispositions: The sponsor-investigator will notify FDA and all reviewing 
IRB’s of any request that a sponsor-investigator return, repair, or dispose of any unit of an 
investigational device. The notice will be made within 30 working days after the request is 
made and will state why the request was made. 
Final report: The sponsor-investigator will notify FDA and all reviewing IRBs within 30 
working days of the completion or termination of the investigation. The sponsor-investigator 
will also submit a final report to FDA and all reviewing IRBs and participating investigators 
Branch vessel embolism (renal, celiac, SMA, etc.) 
 
 
 
 
Branch vessel occlusion (renal, celiac, SMA, etc.)  
 
 
 
 
Branch vessel dissection (renal, celiac, SMA, etc.) 
 
 
 
 
External iliac dissection           
 
 
 
 
Interval iliac occlusion 
 
 
 
 
Ischemic colitis/Colon necrosis                    
 
 
 
 
Late related death 
 
 
 
 
Late unrelated death                  
 
 
 
 
Leg ischemia      
 
 
 
 
Lower extremity embolism    
 
 
 
 
Lower extremity paralysis        
 
 
 
 
MI     
 
 
 
 
Perioperative death                         
 
 
 
 
Renal failure/impairment                           
 
 
 
 
Respiratory failure             
 
 
 
 
Stroke                                   
 
 
 
 
Wound necrosis                        
 
 
 
 

 
 
 
Page 90 of 103 
 
within 6 months after the completion or termination of the investigation. The suggested format 
for final IDE reports will be utilized in preparing the final report as described at:  
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/HowtoMarketYourDev
ice/InvestigationalDeviceExemptionIDE/ucm046717.htm#sugforforidefin 
Clinical Trial Database report: The sponsor-investigator with an applicable study registered 
with the National Institutes of Health (NIH) National Library of Medicine’s (NLM) 
ClinicalTrials.gov will report results of the study within 12 months of the trial reaching its 
completion data regardless of outcomes or if the study is terminated early.    
Failure to obtain informed consent: The sponsor-investigator will submit a report of the use 
of a device without first obtaining informed consent. The report will be made to FDA within 5 
working days after receipt of the notice of such use. 
Other reports: The sponsor-investigator will provide accurate, complete, and current 
information about any aspect of the investigation upon request from the reviewing IRB or FDA. 
4.8 Oversight 
 
 This study will have oversight by a Data Safety Monitoring Board (DSMB) consisting of 
independent scientific and bio-statistical experts, who are not participating as investigators in the study.  
The DSMB will monitor and evaluate the safety of subjects and progress of the study. The board will 
meet after every 5th patient receiving the investigational device and annually during the follow-up 
period to review subject data.  The board will also meet at unscheduled times according to clinical 
necessity. The data safety reports reviewed at each meeting will contain enrollment data and all 
documented adverse events experienced by the participants and treatment outcomes.  The focus of the 

 
 
 
Page 91 of 103 
 
analysis is to determine whether enrollment should continue or be closed and whether the trials should 
continue as originally designed or require modification/amendment.    
4.9 Definitions 
Aortic aneurysm enlargement: ≥5mm as compared to any previous CT measure using orthogonal 
(i.e., perpendicular to the centerline) measurements  
Aortoiliac aneurysm: aneurysm of the abdominal aorta and including one or both of the iliac arteries  
Aneurysm-related mortality: 
Death occurring within 30 days or during hospitalization following the index procedure, unless 
there is evidence of accidental or self-inflicted death. 
Death occurring within 30 days or during hospitalization following conversion to open repair or 
a secondary intervention for migration, Type I and III endoleaks, device integrity failure (e.g., 
fracture), or patency-related events (i.e., device stenosis or occlusion and embolic events), 
unless there is evidence of accidental or self-inflicted death;  
Death occurring within 30 days or during hospitalization for a complication of the aneurysm or 
a complication associated with the device, such as:  
• aortic rupture 
• fistula formation (e.g., aorto-enteric) 
• embolization 
• malperfusion of organ(s) or limb(s) 
Arterial fistula formation: formation of an abnormal connection or passageway between an artery and 
adjacent structures 

 
 
 
Page 92 of 103 
 
Crawford Type IV TAAA: aneurysmal dilation originating within 5 cm of the celiac artery.   
Conversion to Open, Early: any open repair within 30 days of the index procedure involving the 
vasculature in the abdomen and/or pelvis. 
Conversion to Open, Late: any open surgical repair involving stent graft removal after 30days post 
index procedure 
Chronic Obstructive Pulmonary Disease (COPD): forced expiratory volume (FEV1) < 1.0 liter or 
receiving home oxygen  
Disabling stroke: Modified Rankin Score MRS >2 
Distal landing zone: aortic fixation site furthest from the heart  
Embolization: dislodging of an upstream particle that travels downstream causing blockage of free 
flow further downstream. Embolization could result in malperfusion 
Embolus: blood clot that forms at one location (presumably from the aneurysmal sac, aortic neck, or 
adjacent vessels) and is dislodged to another location resulting in ischemic changes  
Emergent:  an aneurysm requiring immediate treatment 
Endoleak:  
Type I: leak occurring at the proximal or distal fixation site, including leakage around 
fenestrations  
Type Ia: leak occurring at the proximal fixation zone of the stent-graft  
Type Ib: leak occurring at the distal fixation zone of the stent graft  

 
 
 
Page 93 of 103 
 
Type Ic: leak occurring at the distal fixation zone of the covered stents in the visceral vessels 
incorporated by the fenestrations  
Type II: leak caused by retrograde flow from patent lumbar or inferior mesenteric arteries  
Type IIIa: leak caused by a defect in the graft fabric 
 Type IIIb: leak caused by inadequate seal between modular graft components  
Type IV:  leak caused by graft fabric porosity, often resulting in a generalized blush of contrast 
within the aneurysm sac  
Endoleak, Early: any endoleak observed within 30 days after device deployment  
Endoleak, Late: any endoleak observed later than 30 days after deployment that was not documented 
during the first 30 days after deployment  
Estimated Glomerular Filtration Rate (eGFR): estimated GFR (mL/min/1.73 m2) = 175 x (Serum 
creatinine)-1.154 x (Age)-0.203x (0.743 if female) x (1.210 if African American)  
Graft Relining: placement of the investigational system that results in landing zones that extend 
beyond the limits of the previously placed graft material 
Limb occlusion: the presence of thrombus within any graft limb that creates occlusion  
Major adverse events: all-cause mortality, bowel ischemia (requiring medical or surgical 
management), myocardial infarction, paraplegia, renal failure, respiratory failure, and stroke 
• All-Cause Mortality: any death occurring within the first 30 days post procedure 

 
 
 
Page 94 of 103 
 
• Bowel Ischemia: Bowel ischemia due to limb or arterial occlusion, graft placement, or 
embolization. 
• Myocardial infarction: raised levels of cardiac biomarkers or ECG changes  
• Paraplegia: spinal cord ischemic event resulting in complete loss of motor function with or 
without loss of sensation in the lower extremities 
• Renal Failure: acute or progressive renal insufficiency leading to the need for dialysis or 
hemofiltration 
• Respiratory failure: prolonged intubation (>48 hours after spinal drain removal or >72 hours 
total) and/or reintubation.  This definition does not put the patient at any increased risk.  The 
high-risk patient population being treated in this study is prone to pre-existing comorbidities, 
including COPD and decreased respiratory function, and may require extended ventilator 
support while in the supine position for spinal drainage.   
• Stroke: neurological deficit that lasts > 24 hours 
Malperfusion of organ(s) or limb(s): loss of flow through a particular vascular bed has been partially 
or completely compromised leaving the said organ or limb ischemic 
Migration, clinically significant: antegrade or retrograde migration that requires surgical or 
endovascular intervention 
Paraparesis: spinal cord ischemic event resulting in partial neurologic deficit in the lower extremities 
Parietal arteries (branches): inferior phrenic, lumbar and middle sacral arteries  
Patency: the state of a vessel that has unimpeded flow into and out of the vessel   
Proximal landing zone: the aortic fixation site closest to the heart 

 
 
 
Page 95 of 103 
 
Proximal fixation length: the aortic fixation site measured from the proximal edge of the graft to the 
start of the aneurysm  
Renal insufficiency: rise in serum creatinine of more than 50% above pre-procedure level which 
results in a serum creatinine >2.0 mg/dl that does not spontaneously resolve  
Technical success:   
• successful delivery (i.e., ability to deliver the implant to the intended implantation site, 
without the need for unanticipated corrective intervention related to delivery); 
• successful and accurate deployment, defined as: 
▪ deployment of the endovascular stent-graft at the intended implantation site. 
▪ patency of all endovascular graft and stent components; absence of device 
deformations (e.g., kinks, stent eversion, mal-deployment, misaligned 
deployment) requiring unplanned placement of an additional device.  
▪ absence of inadvertent covering of aortic branch vessels; and 
• successful withdrawal (i.e., successful withdrawal of the delivery system, without 
need for unanticipated corrective intervention related to withdrawal) 
Thrombus: a blood clot that forms due to injury of a vessel. If the thrombus becomes dislodged and 
travels it is referred to as an embolus  
Treatment success:  a composite of technical success and freedom from the following: 
• aneurysm enlargement i.e. >10-mm as compared to any previous CT measuring orthogonal (i.e., 
perpendicular to centerline) measurements 

 
 
 
Page 96 of 103 
 
• aneurysm-related mortality 
• aneurysm rupture 
• conversion to open repair 
• secondary intervention for migration, type I and III endoleaks, device integrity failure (i.e., 
fracture), and patency-related events (i.e., device stenosis or occlusion and embolic events) 
Type B – Chronic Dissection:  a dissection that takes off distal to the left subclavian artery that is 
greater than 30 days old 
Type B – Subacute Dissection:  a dissection that takes of distal to the left subclavian artery that is 15-
30 days old 
Urgent:  An aneurysm requiring repair within 1 week 
Visceral arteries (branches): celiac, superior mesenteric, inferior mesenteric, renal arteries 

 
 
 
Page 97 of 103 
 
5. Manufacturing Information  
The VTAAA stent graft system utilizes the Medtronic TAAA Debranching Stent Graft System.  
Therefore, the manufacturing information for the system is listed in the following Medtronic regulatory 
submission:   
MAF-2551, Medtronic, TAAA Debranching Stent Graft System Master File 
6. Investigator Agreement and Certification 
The investigator that will be participating in the study includes Dr. Thomas C. Naslund.  I 
certify that all participating investigators will sign the investigator agreement and no investigator will 
be added until the agreement is signed in accordance with 21 CFR 812.29(b)(5). 
The names and addresses of investigators will be provided upon request by the FDA and in 
accordance with 21 CFR 812.150(b) (4). 
7. IRB Information 
Human Research Protections Program 3319 West End Ave., Suite 600 Nashville, TN 37203 
615-322-2918. 
8. Amount to be charged 
The amount charged for the devices used in this investigation will be consistent with the amount 
charged by the manufacturers of the devices to the hospitals.    

 
 
 
Page 98 of 103 
 
9. Labeling 
The VTAAA stent graft system utilizes the Medtronic TAAA Debranching Stent Graft System.  
Therefore, the manufacturing information for the system is listed in the following Medtronic regulatory 
submission:   
MAF-2551, Medtronic, TAAA Debranching Stent Graft System Master File 
10. Medicare Generalizability  
The VTAAA stent graft system is intended to treat thoracoabdominal aortic aneurysms and the 
highest incidence of this disease is observed in Medicare eligible patients.  A 2013 market survey of 
inpatient data revealed that 79.8% (1642/2058) of all thoracoabdominal aortic aneurysms occurred in 
patients over the age of 65.  In that same survey, Medicare was the principal payer in 76.3% of those 
cases and the secondary payer in 82.6% of those cases80.   
Aneurysmal degeneration occurs more commonly in the aging population.  Aging may lead to 
weakening of the aortic wall due to changes in the collagen and elastin. Additionally, comorbidities that 
may increase the risk for aneurysm formation are smoking, chronic obstructive, pulmonary disease, 
hypertension, atherosclerosis, male gender, older age, high body mass, genetic disorders, and family 
history81.   
 
 
 

 
 
 
Page 99 of 103 
 
11. References 
1. 
Standring S. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 40th Edition. Churchill-
Livingstone, Elsevier; 2008. 
2. 
Dapunt OE, Galla JD, Sadeghi AM, et al. The natural history of thoracic aortic aneurysms. The Journal of 
thoracic and cardiovascular surgery. 1994;107(5):1323-1332; discussion 1332-1323. 
3. 
Cambria RA, Gloviczki P, Stanson AW, et al. Outcome and expansion rate of 57 thoracoabdominal aortic 
aneurysms managed nonoperatively. American journal of surgery. 1995;170(2):213-217. 
4. 
cronenwett JL SS, Wall MH. Variables that affect the expansion rate and outcome of small abdominal 
aortic aneurysms. Journal of vascular surgery. 1990;11:260-269. 
5. 
Cronenwett JL, Murphy TF, Zelenock GB, et al. Actuarial analysis of variables associated with rupture of 
small abdominal aortic aneurysms. Surgery. 1985;98(3):472-483. 
6. 
Bickerstaff LK, Pairolero PC, Hollier LH, et al. Thoracic aortic aneurysms: a population-based study. 
Surgery. 1982;92(6):1103-1108. 
7. 
McNamara JJ, Pressler VM. Natural history of arteriosclerotic thoracic aortic aneurysms. The Annals of 
thoracic surgery. 1978;26(5):468-473. 
8. 
Pressler V, McNamara JJ. Thoracic aortic aneurysm: natural history and treatment. The Journal of 
thoracic and cardiovascular surgery. 1980;79(4):489-498. 
9. 
Crawford ES, DeNatale RW. Thoracoabdominal aortic aneurysm: observations regarding the natural 
course of the disease. Journal of vascular surgery. 1986;3(4):578-582. 
10. 
Moreno-Cabral CE, Miller DC, Mitchell RS, et al. Degenerative and atherosclerotic aneurysms of the 
thoracic aorta. Determinants of early and late surgical outcome. The Journal of thoracic and 
cardiovascular surgery. 1984;88(6):1020-1032. 
11. 
de Bakey ME, McCollum CH, Graham JM. Surgical treatment of aneurysms of the descending thoracic 
aorta: long-term results in 500 patients. The Journal of cardiovascular surgery. 1978;19(6):571-576. 
12. 
Cooke JC, Cambria RP. Simultaneous tracheobronchial and esophageal obstruction caused by a 
descending thoracic aneurysm. Journal of vascular surgery. 1993;18(1):90-94. 
13. 
Piazza M, Ricotta JJ, 2nd. Open surgical repair of thoracoabdominal aortic aneurysms. Annals of 
vascular surgery. 2012;26(4):600-605. 
14. 
Rectenwald JE, Huber TS, Martin TD, et al. Functional outcome after thoracoabdominal aortic aneurysm 
repair. Journal of vascular surgery. 2002;35(4):640-647. 
15. 
Schepens MA, Heijmen RH, Ranschaert W, Sonker U, Morshuis WJ. Thoracoabdominal aortic aneurysm 
repair: results of conventional open surgery. European journal of vascular and endovascular surgery : 
the official journal of the European Society for Vascular Surgery. 2009;37(6):640-645. 
16. 
Wong DR, Parenti JL, Green SY, et al. Open repair of thoracoabdominal aortic aneurysm in the modern 
surgical era: contemporary outcomes in 509 patients. Journal of the American College of Surgeons. 
2011;212(4):569-579; discussion 579-581. 
17. 
Bensley RP, Curran T, Hurks R, et al. Open repair of intact thoracoabdominal aortic aneurysms in the 
American College of Surgeons National Surgical Quality Improvement Program. Journal of vascular 
surgery. 2013;58(4):894-900. 
18. 
Nathan DP, Brinster CJ, Woo EY, Carpenter JP, Fairman RM, Jackson BM. Predictors of early and late 
mortality following open extent IV thoracoabdominal aortic aneurysm repair in a large contemporary 
single-center experience. Journal of vascular surgery. 2011;53(2):299-306. 
19. 
Menard MT, Nguyen LL, Chan RK, et al. Thoracovisceral segment aneurysm repair after previous 
infrarenal abdominal aortic aneurysm surgery. Journal of vascular surgery. 2004;39(6):1163-1170. 
20. 
Coselli JS, Bozinovski J, LeMaire SA. Open surgical repair of 2286 thoracoabdominal aortic aneurysms. 
The Annals of thoracic surgery. 2007;83(2):S862-864; discussion S890-862. 

 
 
 
Page 100 of 103 
 
21. 
Tabayashi K, Saiki Y, Kokubo H, et al. Protection from postischemic spinal cord injury by perfusion 
cooling of the epidural space during most or all of a descending thoracic or thoracoabdominal 
aneurysm repair. General thoracic and cardiovascular surgery. 2010;58(5):228-234. 
22. 
Messe SR, Bavaria JE, Mullen M, et al. Neurologic outcomes from high risk descending thoracic and 
thoracoabdominal aortic operations in the era of endovascular repair. Neurocritical care. 
2008;9(3):344-351. 
23. 
Coselli JS, LeMaire SA, Miller CC, 3rd, et al. Mortality and paraplegia after thoracoabdominal aortic 
aneurysm repair: a risk factor analysis. The Annals of thoracic surgery. 2000;69(2):409-414. 
24. 
Archer W, Hoch, and Kranner. Cardiac function is a risk factor for paralysis in thoracoabdominal aortic 
replacement. Journal of vascular surgery. 1998;27(5):821-830. 
25. 
Greenberg RK, Lu Q, Roselli EE, et al. Contemporary analysis of descending thoracic and 
thoracoabdominal aneurysm repair: a comparison of endovascular and open techniques. Circulation. 
2008;118(8):808-817. 
26. 
Safi HJ, Estrera AL, Azizzadeh A, Coogan S, Miller CC, 3rd. Progress and future challenges in 
thoracoabdominal aortic aneurysm management. World journal of surgery. 2008;32(3):355-360. 
27. 
Cambria RP, Clouse WD, Davison JK, Dunn PF, Corey M, Dorer D. Thoracoabdominal aneurysm repair: 
results with 337 operations performed over a 15-year interval. Annals of surgery. 2002;236(4):471-479; 
discussion 479. 
28. 
Zanetti PP, Krasoń M, Walas R, et al. “Open” repair of ruptured thoracoabdominal aortic aneurysm 
(experience of 51 cases). Kardiochirurgia i Torakochirurgia Polska = Polish Journal of Cardio-Thoracic 
Surgery. 2015;12(2):119-125. 
29. 
Andersen ND, Keenan JE, Ganapathi AM, Gaca JG, McCann RL, Hughes GC. Current management and 
outcome of chronic type B aortic dissection: results with open and endovascular repair since the advent 
of thoracic endografting. Annals of cardiothoracic surgery. 2014;3(3):264-274. 
30. 
Chou H-P, Chang H-T, Chen C-K, et al. Outcome comparison between thoracic endovascular and open 
repair for type B aortic dissection: A population-based longitudinal study. Journal of the Chinese 
Medical Association.78(4):241-248. 
31. 
Verhoeven ELG, Muhs BE, Zeebregts CJAM, et al. Fenestrated and Branched Stent-grafting After 
Previous Surgery Provides a Good Alternative to Open Redo Surgery. European Journal of Vascular and 
Endovascular Surgery. 2007;33(1):84-90. 
32. 
Liewald F, Kapfer X, Gorich J, Halter G, Tomczak R, Scharrer-Pamler R. Endograft treatment of 
anastomotic aneurysms following conventional open surgery for infrarenal aortic aneurysms. European 
journal of vascular and endovascular surgery : the official journal of the European Society for Vascular 
Surgery. 2001;21(1):46-50. 
33. 
Dorsey C, Chandra V, Lee JT. The "Terrace Technique"-Totally Endovascular Repair of a Type IV 
Thoracoabdominal Aortic Aneurysm. Annals of vascular surgery. 2014. 
34. 
Cariati M, Mingazzini P, Dallatana R, Rossi UG, Settembrini A, Santuari D. Endovascular treatment of a 
symptomatic thoracoabdominal aortic aneurysm by chimney and periscope techniques for total 
visceral and renal artery revascularization. Cardiovascular and interventional radiology. 2014;37(1):251-
256. 
35. 
Cariati M, Rossi UG. Letter REPLY Re: "Endovascular Treatment of a Symptomatic Thoracoabdominal 
Aortic Aneurysm by Chimney and Periscope Techniques for Total Visceral and Renal Artery 
Revascularization". Cardiovascular and interventional radiology. 2014. 
36. 
Pecoraro F, Pfammatter T, Mayer D, et al. Multiple periscope and chimney grafts to treat ruptured 
thoracoabdominal and pararenal aortic aneurysms. Journal of endovascular therapy : an official journal 
of the International Society of Endovascular Specialists. 2011;18(5):642-649. 
37. 
Scali ST, Feezor RJ, Chang CK, et al. Critical analysis of results after chimney endovascular aortic 
aneurysm repair raises cause for concern. Journal of vascular surgery. 2014. 

 
 
 
Page 101 of 103 
 
38. 
Moulakakis KG, Mylonas SN, Avgerinos E, et al. The chimney graft technique for preserving visceral 
vessels during endovascular treatment of aortic pathologies. Journal of vascular surgery. 
2012;55(5):1497-1503. 
39. 
Kasirajan K. Branched grafts for thoracoabdominal aneurysms: off-label use of FDA-approved devices. 
Journal of endovascular therapy : an official journal of the International Society of Endovascular 
Specialists. 2011;18(4):471-476. 
40. 
Lobato AC, Camacho-Lobato L. A new technique to enhance endovascular thoracoabdominal aortic 
aneurysm therapy--the sandwich procedure. Seminars in vascular surgery. 2012;25(3):153-160. 
41. 
Oderich GS, Ricotta JJ, 2nd. Modified fenestrated stent grafts: device design, modifications, 
implantation, and current applications. Perspectives in vascular surgery and endovascular therapy. 
2009;21(3):157-167. 
42. 
Oderich GS, Fatima J, Gloviczki P. Stent graft modification with mini-cuff reinforced fenestrations for 
urgent repair of thoracoabdominal aortic aneurysms. Journal of vascular surgery. 2011;54(5):1522-
1526. 
43. 
Haulon S, Greenberg RK. Part Two: Treatment of type IV thoracoabdominal aneurysms--fenestrated 
stent-graft repair is now the best option. European journal of vascular and endovascular surgery : the 
official journal of the European Society for Vascular Surgery. 2011;42(1):4-8. 
44. 
Oderich GS, Mendes BC, Correa MP. Preloaded guidewires to facilitate endovascular repair of 
thoracoabdominal aortic aneurysm using a physician-modified branched stent graft. Journal of vascular 
surgery. 2014;59(4):1168-1173. 
45. 
Benjelloun A, Henry M, Ghannam A, et al. Endovascular treatment of a tuberculous thoracoabdominal 
aneurysm with the Multilayer stent. Journal of endovascular therapy : an official journal of the 
International Society of Endovascular Specialists. 2012;19(1):115-120. 
46. 
Vaislic CD, Fabiani JN, Chocron S, et al. One-year outcomes following repair of thoracoabdominal 
aneurysms with the multilayer flow modulator: report from the STRATO trial. Journal of endovascular 
therapy : an official journal of the International Society of Endovascular Specialists. 2014;21(1):85-95. 
47. 
Sultan S, Hynes N. One-year results of the multilayer flow modulator stent in the management of 
thoracoabdominal aortic aneurysms and type B dissections. Journal of endovascular therapy : an official 
journal of the International Society of Endovascular Specialists. 2013;20(3):366-377. 
48. 
Lazaris AM, Maheras AN, Vasdekis SN. A multilayer stent in the aorta may not seal the aneurysm, 
thereby leading to rupture. Journal of vascular surgery. 2012;56(3):829-831. 
49. 
Ferrero E, Gibello L, Ferri M, Viazzo A, Nessi F. Aortic arch rupture after multiple multilayer stent 
treatment of a thoracoabdominal aneurysm. Journal of vascular surgery. 2013. 
50. 
Cavalcante RN, Nishinari K, Yazbek G, Krutman M, Bomfim G, Wolosker N. Severe visceral ischemia and 
death after multilayer stent deployment for the treatment of a thoracoabdominal aortic aneurysm. 
Journal of vascular surgery. 2014. 
51. 
de Vries JP. Treatment of complex thoracoabdominal or juxtarenal aortic aneurysms with a Multilayer 
stent. Journal of endovascular therapy : an official journal of the International Society of Endovascular 
Specialists. 2012;19(1):125-127. 
52. 
Sherif Sultan NH, and Mohamed Sultan. When not to implant the multilayer flow modulator: lessons 
learned from application outside the indications for use in patients wtih thoracoabdominal pathologies. 
Journal of Endovascular Therapy. 2014;21:96-112. 
53. 
Bin Jabr A, Lindblad B, Dias N, Resch T, Malina M. Efficacy and durability of the chimney graft technique 
in urgent and complex thoracic endovascular aortic repair. Journal of vascular surgery. 2015;61(4):886-
894 e881. 
54. 
Filippi F, Ficarelli R, Tirotti C, Stella N, Taurino M. Emergent fully endovascular treatment of a free 
ruptured thoracoabdominal aneurysm. Annals of vascular surgery. 2015;29(4):842 e849-813. 

 
 
 
Page 102 of 103 
 
55. 
Marino M, Kasemi H, Di Angelo CL, Fadda GF. Ruptured thoracoabdominal aneurysm treatment with 
modified chimney stent graft. The Annals of thoracic surgery. 2014;98(2):e37-40. 
56. 
Schlosser FJ, Aruny JE, Freiburg CB, Mojibian HR, Sumpio BE, Muhs BE. The chimney procedure is an 
emergently available endovascular solution for visceral aortic aneurysm rupture. Journal of vascular 
surgery. 2011;53(5):1386-1390. 
57. 
Clouse WD, Hallett JW, Jr., Schaff HV, et al. Acute aortic dissection: population-based incidence 
compared with degenerative aortic aneurysm rupture. Mayo Clinic proceedings. 2004;79(2):176-180. 
58. 
Mehta RH, Manfredini R, Hassan F, et al. Chronobiological patterns of acute aortic dissection. 
Circulation. 2002;106(9):1110-1115. 
59. 
Erbel R, Alfonso F, Boileau C, et al. Diagnosis and management of aortic dissection. European heart 
journal. 2001;22(18):1642-1681. 
60. 
Thrumurthy SG, Karthikesalingam A, Patterson BO, Holt PJ, Thompson MM. The diagnosis and 
management of aortic dissection. Bmj. 2012;344:d8290. 
61. 
Eggebrecht H, Nienaber CA, Neuhauser M, et al. Endovascular stent-graft placement in aortic 
dissection: a meta-analysis. European heart journal. 2006;27(4):489-498. 
62. 
Kim KM, Donayre CE, Reynolds TS, et al. Aortic remodeling, volumetric analysis, and clinical outcomes 
of endoluminal exclusion of acute complicated type B thoracic aortic dissections. Journal of vascular 
surgery. 2011;54(2):316-324; discussion 324-315. 
63. 
Yang CP, Hsu CP, Chen WY, et al. Aortic remodeling after endovascular repair with stainless steel-based 
stent graft in acute and chronic type B aortic dissection. Journal of vascular surgery. 2012;55(6):1600-
1610. 
64. 
Andacheh ID, Donayre C, Othman F, Walot I, Kopchok G, White R. Patient outcomes and thoracic aortic 
volume and morphologic changes following thoracic endovascular aortic repair in patients with 
complicated chronic type B aortic dissection. Journal of vascular surgery. 2012;56(3):644-650; 
discussion 650. 
65. 
Mani K, Clough RE, Taylor PR. Regarding "patient outcomes and thoracic aortic volume and 
morphologic changes following thoracic endovascular aortic repair in patients with complicated chronic 
type B aortic dissection". Journal of vascular surgery. 2013;57(3):898. 
66. 
O'Callaghan A, Mastracci TM, Eagleton MJ. Staged endovascular repair of thoracoabdominal aortic 
aneurysms limits incidence and severity of spinal cord ischemia. Journal of vascular surgery. 
2015;61(2):347-354.e341. 
67. 
Banga PV, Oderich GS, Reis de Souza L, et al. Neuromonitoring, Cerebrospinal Fluid Drainage, and 
Selective Use of Iliofemoral Conduits to Minimize Risk of Spinal Cord Injury During Complex 
Endovascular Aortic Repair. Journal of endovascular therapy : an official journal of the International 
Society of Endovascular Specialists. 2016;23(1):139-149. 
68. 
Fratesi F, Handa A, Uberoi R, Sideso E. Chimney-Graft as a Bail-Out Procedure for Endovascular 
Treatment of an Inflammatory Juxtarenal Abdominal Aortic Aneurysm. Case reports in vascular 
medicine. 2015;2015:531017. 
69. 
Oderich GS, Mendes BC, Kanamori KS. Technique of implantation and bail-out maneuvers for 
endovascular fenestrated repair of juxtarenal aortic aneurysms. Perspectives in vascular surgery and 
endovascular therapy. 2013;25(1-2):28-37. 
70. 
Roselli EE, Greenberg RK, Pfaff K, Francis C, Svensson LG, Lytle BW. Endovascular treatment of 
thoracoabdominal aortic aneurysms. The Journal of thoracic and cardiovascular surgery.133(6):1474-
1482.e1471. 
71. 
Suess T, Anderson J, Danielson L, et al. Examination of near-wall hemodynamic parameters in the renal 
bridging stent of various stent graft configurations for repairing visceral branched aortic aneurysms. 
Journal of vascular surgery. 2016;64(3):788-796. 

 
 
 
Page 103 of 103 
 
72. 
Mohabbat W, Greenberg RK, Mastracci TM, Cury M, Morales JP, Hernandez AV. Revised duplex criteria 
and outcomes for renal stents and stent grafts following endovascular repair of juxtarenal and 
thoracoabdominal aneurysms. Journal of vascular surgery. 2009;49(4):827-837; discussion 837. 
73. 
Registry. BSfETatGCoAS-GTfARG. Early results of fenestrated endovascular repair of juxtarenal aortic 
aneurysms in the United Kingdom. Circulation. 2012;125(22):2707-2715. 
74. 
Greenberg R, Eagleton M, Mastracci T. Branched endografts for thoracoabdominal aneurysms. The 
Journal of thoracic and cardiovascular surgery. 2010;140(6 Suppl):S171-178. 
75. 
Chuter TA, Rapp JH, Hiramoto JS, Schneider DB, Howell B, Reilly LM. Endovascular treatment of 
thoracoabdominal aortic aneurysms. Journal of vascular surgery. 2008;47(1):6-16. 
76. 
Assar AN, Zarins CK. Ruptured abdominal aortic aneurysm: a surgical emergency with many clinical 
presentations. Postgraduate medical journal. 2009;85(1003):268-273. 
77. 
Gkremoutis A, Schmandra T, Meyn M, Schmitz-Rixen T, Keese M. Hybrid Approach to Emergent and 
Urgent Treatment of Complex Thoracoabdominal Aortic Pathology. European Journal of Vascular and 
Endovascular Surgery. 2014;48(4):407-413. 
78. 
Norwood MGA, Polimenovi NM, Sutton AJ, Bown MJ, Sayers RD. Abdominal Aortic Aneurysm Repair in 
Patients with Chronic Renal Disease. European Journal of Vascular and Endovascular Surgery.27(3):287-
291. 
79. 
Guntani A, Okadome J, Kawakubo E, et al. Clinical Results of Endovascular Abdominal Aortic Aneurysm 
Repair in Patients with Renal Insufficiency without Hemodialysis. Annals of Vascular Diseases. 
2012;5(2):166-171. 
80. 
MarketScan Inpatient View by Truven Health Analytics d. 
81. 
Frederick JR, Woo YJ. Thoracoabdominal aortic aneurysm. Annals of cardiothoracic surgery. 
2012;1(3):277-285. 
82.  
Jean Bismuth, MD, Bruce H. Gray, DO, Andrew Holden, MD, Christopher Metzger, MD, Jean Panneton, 
MD, on behalf of the VBX FLEX Study Investigators. Pivotal Study of a Next-Generation Balloon-
Expandable Stent-Graft for Treatment of Iliac Occlusive Disease J Endovasc Ther. 2017 Oct;24(5):629-
637