Prospective Randomized Control Trial of Open Versus Robotic REtrOmuscular Ventral Hernia Repair (ORREO Trial)
Phase: NA
Conditions: Ventral Hernia
Sponsor: Prisma Health-Upstate

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Protocol Title:  Prospective Randomized Control Trial of Open versus Robotic REtrOmuscular 
Ventral Hernia repair   [ORREO Trial] 
 
NCT: 03007758 
 
Date: 07 Apr 2017 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ORREO Trial Protocol: 

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Date: 07Apr2017 
 
Title:  Prospective Randomized Control Trial of Open versus Robotic REtrOmuscular Ventral 
Hernia repair   [ORREO Trial] 
 
PI: Jeremy A. Warren, MD 
 
Co-I: Alfredo M. Carbonell, DO 
         Melisa G. Wiese, APRN, NP-C 
 
Background: 
Due to the variety of hernia repair techniques and materials available, and the heterogeneity of 
the hernia patient population, there is no consensus standard of care for ventral hernia repair.  
The Rives-Stoppa retromuscular hernia repair is considered by many the standard by which all 
other techniques should be compared {Israelsson:2006gn}{Helgstrand:2013ev}.  There is good 
long term data on this technique, with overall recurrence rate of 7.4% and wound complication 
rates of 9.3% (3).  Unfortunately, many factors that lead to development of ventral and 
incisional hernias are also those that increase the risk of recurrence and wound morbidity.  
Obesity, COPD, DM, and tobacco abuse are particularly troublesome conditions that confer 
higher morbidity after abdominal wall reconstruction (AWR).  While preoperative weight loss 
and smoking cessation are modifiable risk factors, many patients will not successfully lose 
weight, are not eligible for bariatric surgery, will not stop smoking, and are at risk for 
developing increasingly complex hernias or presenting with acute incarceration requiring 
urgent repair.   
 
Since its initial description, laparoscopic ventral hernia repair (LVHR) was quickly adopted and 
has been shown to significantly decrease wound morbidity, with comparable recurrence rates 
(2) (3) (4).  Though our preferred technique is an open retromuscular VHR (OVHR), laparoscopy 
remains an important technique for high risk patients.  However, the hernia defect itself is 
typically not closed, which can result in pseudorecurrence and eventration of the mesh through 
the hernia defect, particularly with larger defects (5).  Additionally, mesh placed in the 
intraperitoneal position has the potential to complicate subsequent abdominal operations, with 
incidence of unplanned enterotomy or bowel resection as high as 20% (6) (7).  
 
The development of our robotic retromuscular ventral hernia repair (RRVHR) technique 
combines the benefits of the OVHR (reconstruction of native anatomy and a functional 
abdominal wall, placement of mesh in the retromuscular space) with those of LVHR (lower 
wound morbidity).  Understandably, during the early development of a novel technique, we 
have been highly selective of our patients, typically selecting those we deem to have a high 
chance of a successful repair, and those with small to moderate defects as we refined the 
technical details of the operation.  As our experience has increased and technique refined, we 
have been able to repair more complex patients with larger, more complex hernia defects.  We 

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anticipate that these patients with the highest risk of wound morbidity will have the greatest 
clinical benefit from the robotic approach. 
 
We describe a novel surgical technique, using new technology to duplicate the abdominal wall 
reconstruction achieved with OVHR in a minimally invasive fashion.  While the feasibility of 
robotic VHR has been described, previous reports describe essentially a LVHR with 
intraperitoneal mesh placement utilizing the robot rather than a laparoscope.  The only other 
report of a similar technique, and the inspiration of our development of RRVHR, is a 
transabdominal, retromuscular repair of umbilical hernia with plication of diastasis rectus 
described by Dr. Abdalla (8).  The ability to duplicate a complete abdominal wall reconstruction 
with mesh reinforcement in high risk patients using a minimally invasive technique is a 
significant step forward in improving the outcomes in VHR.  To our knowledge, we have the 
largest experience with this technique and the first reported outcomes data, which were 
presented at the World Hernia Congress, April 2015 (10). 
  
Purpose:  
The purpose of this study is to determine how the robotic retromuscular hernia repair 
compares to the open retromuscular hernia repair for large hernia defects in patients at higher 
risk of wound complications. 
 
Hypothesis: 
We hypothesize that the robotic retromuscular ventral hernia repair improves the clinical 
composite outcome, as compared to open retromuscular hernia repair, in high risk patients. 
 
Primary Endpoints:   
1. Composite Outcome (See full description below) 
a. Surgical Site Occurrence (excluding simple seroma) 
b. Surgical Site Infection 
c. Hospital Readmission 
d. Hernia Recurrence 
 
Secondary Endpoints: 
1. All Surgical Site Occurrences 
2. Surgical Site Occurrences requiring procedural intervention 
3. All Surgical Site Infections 
4. Surgical Site Infections requiring procedural intervention 
5. Length of Stay 
6. Operative Time 
7. Quality of Life 
8. Cost 
 
Composite Outcome: 
In order to adequately power this study and provide a clinically relevant outcome measure, a 
composite outcome was designed to capture the outcomes that are considered clinically 

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significant.  As such, simple seroma, which is very common, is excluded.  Any seroma requiring 
procedural intervention will be included.  Management of seroma or hematoma requiring 
intervention is discussed below under “Management of Complications.”  Other SSOs, such as 
skin dehiscence, cellulitis, hematoma or skin necrosis, are included as these are more likely to 
require some intervention, such as local wound care or drainage, or some additional cost, such 
as antibiotic therapy.  Similarly, SSIs frequently require additional intervention and cost.   
 
Study Design: 
Prospective randomized control trial of robotic retromuscular ventral hernia repair versus open 
retromuscular ventral hernia repair in patients at high risk for adverse outcome.  [Open versus 
Robotic REtrOmuscular Incisional hernia repair; ORREO trial] 
 
Patient Selection: 
All patients presenting to the Greenville Health System Hernia Center who meet the inclusion 
criteria will be considered for enrollment. Patients who agree to participate will be randomized 
to robotic retromuscular ventral hernia repair (group 1, RRVHR) or open retromuscular ventral 
hernia repair (group 2, OVHR).  Randomization will occur in the office setting to allow 
appropriate scheduling of the case.   
 
Participant Enrollment: 50 patients per study group (100 patients total) 
 
 
Inclusion Criteria: 
 
 
>18 years old 
 
 
Ventral or incisional hernia measuring >7cm and < 15cm 
 
 
At least one of the following risk factors: 
 
 
 
BMI >30 
 
 
 
COPD 
 
 
 
DM 
 
 
 
Current smoker (within 1 month) 
 
 
Exclusion Criteria: 
 
 
Current abdominal or abdominal wall infection 
 
 
Presence of ileostomy, colostomy, or ileal conduit 
 
 
CDC wound class 3 or 4 
 
 
Hernia defect < 7cm or >15cm 
 
 
Pregnant women will be excluded from participating in this study. 
 
 
 
Methods: 
Prospective randomized control trial of robotic retromuscular ventral hernia repair versus open 
retromuscular ventral hernia repair in patients at high risk for adverse outcome.  [Open versus 
Robotic REtrOmuscular Incisional hernia repair; ORREO trial].  Patients who agree to participate 
will be randomized to robotic retromuscular ventral hernia repair (group 1, RRVHR) or open 
retromuscular ventral hernia repair (group 2, OVHR).  Randomization will be performed using 
the randomize function in the Redcap database.   

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Data Collection: 
All patients will be entered prospectively into the Americas Hernia Society Quality Collaborative 
(AHSQC) database and followed prospectively.   For data points that will be collected for trial 
purposes that are not contained within the AHSQC dataset, a Redcap database will be used.   
 
Within the AHSQC, the following data is collected:  Preoperative Patient Reported Outcomes via 
a validated, hernia specific quality of life questionnaire.  Demographic data include age, sex, 
ethnicity, zip code, and insurance coverage.   Patient characteristics include DM, COPD, HTN, 
immunosuppression, smoking status, hepatic disease, renal disease, antiplatelet or 
anticoagulant therapy, height/weight/BMI, history of previous hernia repair (including number 
of repairs, type of repair, type of mesh), history of previous abdominal wall infection, and 
functional status.  Operative details include hernia width, height, presence of prior mesh, 
operative time, mesh selection, size of mesh placed, position of mesh placement, choice of 
mesh fixation, ability to close the midline fascia, technique for closure, use of component 
separation technique, and intraoperative complications.  Hospital data will include LOS and any 
acute medical complications. Postoperative follow-up will occur at 2 weeks, 6 weeks, 6 months, 
1 year, and 2 years.  Patient Reported Outcomes will be collected at each of these post-
operative visits.  Cost data will be obtained from the Greenville Health System office of Business 
Intelligence after discharge from the index hospital stay, and include any readmission or 
additional procedural intervention.   
 
Additional data not contained within the AHSQC, including patient account number, total 
operative time in minutes, total anesthesia time, and EBL, will be collected prospectively and 
recorded at the time of surgery completion.  Operative time will be recorded as total anesthesia 
time and total operative time. 
 
Operative Technique 
Open Retromuscular Technique 
• Midline laparotomy 
• Adhesiolysis 
• Removal of any prior mesh 
• Defect measurement 
• Bilateral retromuscular dissection, extending at least 5cm above and below the 
defect 
• TAR (if necessary for posterior / anterior fascial closure OR for mesh coverage of 
more laterally oriented defect) 
• Posterior sheath closure 
• Dissected space measured 
• Mesh placement (Vitamesh) 
• Mesh fixation at minimum of 4 fixation points  
• Anterior fascia closure using running, small-bite technique using slowly 
absorbable suture 

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• Skin closure with subcuticular fast-absorbing suture and surgical glue 
• No drains will be placed 
 
 
Robotic Retromuscular Ventral Hernia Repair 
One of the following techniques, depending on location and technical feasibility. 
 
 
Double-Dock Technique 
• Three right (or left) lateral abdominal wall trocars 
• Adhesiolysis and hernia reduction 
• Removal of any prior intraperitoneal mesh 
• Contralateral retromuscular dissection, extending 5cm above and below 
defect 
• Contralateral transversus abdominis release with placement of right-
sided trocars 
• Mesh placement (Vitamesh) 
• Intracororeal measurement of hernia defect and dissected space 
• Mesh fixation at minimum of 4 fixation points 
• Redock on the left (or right)  
• Contralateral retromuscular dissection and transversus abdominis release 
• Closure of posterior rectus sheath using slowly absorbable self-fixating 
suture 
• Deployment of mesh 
• Closure of hernia defect using slowly absorbable self-fixating suture 
 
 
Single-Dock Technique 
• Three right (or left) lateral abdominal wall trocars, with 4th assistant 
trocar placed, location at the discretion of the surgeon. 
• Adhesiolysis and hernia reduction 
• Removal of any prior intraperitoneal mesh 
• Incision of ipsilateral posterior rectus sheath 
• Retromuscular dissection from lateral to medial, ending at the linea alba 
• Preperitoneal dissection along the midline, including reduction of the 
hernia sac 
• Contralateral retromuscular dissection 
• Contralateral transversus abdominis release (if indicated) 
• Intracorporeal measurement of hernia defect 
• Closure of hernia defect with slowly absorbable self-fixating suture 
• Measurement of dissected space 
• Placement of mesh (Vitamesh) 
• Mesh fixation at minimum of 4 points 

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• Closure of posterior rectus sheath 
 
Single-Dock Technique, Epigastric or Suprapubic Dock 
• Three trocars along the upper or lower abdomen, with assistant trocar 
placed at surgeons discretion 
• Adhesiolysis and hernia reduction 
• Removal of any prior intraperitoneal mesh 
• Transverse incision of bilateral posterior rectus sheath  
• Bilateral retromuscular dissection, combined with midline preperitoneal 
dissection extending from at least 5cm below the defect to at least 5cm 
above 
• Unilateral or bilateral transversus abdominis release (if indicated) 
• Intracorporeal measurement of hernia defect 
• Closure of hernia defect with slowly absorbable self-fixating suture 
• Measurement of dissected space 
• Placement of mesh (Vitamesh) 
• Mesh fixation at a minimum of 4 points 
• Closure of posterior rectus sheath 
 
Perioperative Care 
• Enhanced Recovery After Surgery (ERAS) protocol will be used for all patients as 
follows: 
o Preoperative electrolyte beverage 2-4 hours preop 
o Preoperative pain cocktail: (except in case of allergy or other specific 
contraindication) 
 Celebrex 400mg 
 Lyrica 75mg 
 Tylenol 1000mg 
o Avoidance of intraoperative narcotics 
o Ketamine bolus and infusion intraoperatively 
o Lidocaine infusion intraoperatively 
o Postoperative ketamine infusion continued on floor.  Management of 
ketamine infusion by Anesthesia pain service 
o Postoperative intravenous acetaminophen and ketorolac (except in case 
of allergy or specific contraindication) 
o Oral narcotic (hydrocodone or oxycodone) given for breakthrough pain 
only 
o Oral intake beginning not later than morning of postoperative day 1 
 
 
 
Management of Complications 

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• Surgical site infections will be managed by bedside or in-office opening and 
drainage of the surgical site, or percutaneous drainage of fluid collections as 
indicated, according with standard surgical principles.   
• Operative intervention will be reserved for patients presenting with sepsis, or 
after failed non-operative therapy.   
• Antibiotics at surgeon discretion. 
• Surgical site occurrences (seroma or hematoma) will be treated only if patients 
have ongoing intractable pain related to the seroma, or there is concern for 
possible infection.  Should intervention be required, simple aspiration, repeated 
as necessary, is the preferred approach, with percutaneous drain placement 
reserved for patients with suspected infection, or those requiring multiple 
reaspirations. 
 
Follow-up:   
 
Two week  
 
6 week 
 
6 month  
 
1 year 
 
2 years 
 
Quality of Life 
Will be assess via AHSQC Patient Reported Outcomes Quality of life questionnaire will be 
administered at preoperative visit and each planned postoperative visit, and will be 
administered by the Study Coordinator, Principal Investigator or Co-Investigator.   
 
Sample Size & Statistical Analysis 
Based on our current RRVHR outcomes and utilizing our entire OVHR database, which is 
maintained in a prospective fashion, we obtained a composite outcome using the combination 
of SSO (excluding seromas), SSI, hospital readmission, and hernia recurrence. For OVHR, the 
incidence of the composite outcome is 52.2% and for RRVHR 24.1%.  Using a power of 80% and 
a significance of 5%, we estimate that 46 patients enrolled in each arm will demonstrate a 
difference in our primary endpoint.  We plan to enroll at least 50 patients in each arm to allow 
for potential patient withdrawal or failure to maintain follow-up.   
 
Differences in discrete primary and secondary outcomes (SSO, SSI, readmission, recurrence) 
between the OVHR and RRVHR groups will be analyzed using Chi-squared tests, or Fisher's Exact 
Test for small sample sizes (N≤ 6).  Differences in continuous outcomes (length of stay, 
operative time, and costs) between the OVHR and RRVHR groups will be determined using 
students t-test and Mann-Whitney U tests. P-values <0.05 will be considered indicative of 
statistical significance. All analysis will be completed using R statistical software (R version 
3.0.2). 
 

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Adverse Events:  Defined as any unfavorable or any unintended sign, symptom or disease that 
is reported by the patient to have occurred, or a worsening of a preexisting condition.  Adverse 
events will be recorded and detailed.   
 
Potential Risks: 
The following are possible complications specific to hernia repair, and may occur after either 
open or robotic repair: 
• Seroma:  A seroma is a collection of watery fluid below the skin that occurs in 
the space that is separated during surgery or in the space where your hernia 
was.  This occurs in up to 50% of patients.  This is almost always treated with 
observation.  If treatment is needed, a small needle or tube may be placed to 
drain the fluid.   
• Hematoma:  A hematoma is a collection of bloody fluid below the skin that 
occurs in the space that is separated during surgery or in the space where your 
hernia was.  This may occur in about 10-15% of patients.  This is almost always 
treated with observation.  If treatment is needed, a small needle or tube may be 
placed to drain the fluid.   
• Skin dehiscence:  Dehiscence is a separation of the skin at the site(s) of 
incision(s).  This occurs in less than 5% of cases.  Treatment may require a gauze 
or possibly a vacuum dressing to be placed in the wound until it heals.  Healing 
time will depend on the size of the area of the incision that separates. 
• Skin necrosis:  Poor blood flow to a portion of the skin may cause it to die 
(necrosis).  This occurs in less than 5% of cases.  Treatment may be simple 
observation or may require removal of portions of the dead skin and fatty tissue.  
A gauze or vacuum dressing may be placed in the wound until it heals.  Healing 
time will depend on the size of the area of skin necrosis. 
• Surgical site infection:  A surgical site infection is one that occurs in the skin or 
fatty tissue, in between the layers of the abdominal wall that are separated to 
repair the hernia, or inside the abdomen.  This occurs in 5-20% of patients. 
Treatment may require antibiotics, opening of the incision, or placement of a 
needle or tube to drain the infection.  If the incision is opened, a gauze or 
vacuum dressing may be placed in the wound until it heals.  Healing time will 
depend on the size of the wound. 
• Mesh infection:  Infection may occur in the space where the mesh is located.  
This occurs in less than 5% of cases.  Most often, this is treated exactly as other 
surgical site infection.  However, if the infection does not go away, removal of 
the mesh may be needed.  This is a rare. 
• Bowel injury:  Because we are working inside your abdomen, there is a risk of 
injury to your small or large intestine, which occurs in about 1% of cases.  If this 
occurs and is seen at the time of surgery, it is repaired immediately.  There is a 
small chance that a bowel injury could be missed, which may cause you to 
become seriously ill and likely require additional operation(s) to repair the 
bowel, prolonged hospital stay, or even result in death.   

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• Hernia recurrence:  there is a 5-10% chance that your hernia will come back. 
 
Any surgery has a risk of some complications, which may include: 
• Venous thromboembolism (blood clot):  Blood may clot within the vessels of the 
body, causing swelling of the leg(s).  This occurs in about 2% of patients.  If the 
blood clot breaks free from the vessels, they can travel to the vessels in the 
lungs, which can be fatal.  Fatal blood clots are rare events.  A blood thinner is 
needed for treatment.  You will be given an injection of a blood thinner prior to 
the operation, as well as devices that will squeeze your calves, in order to 
prevent you from getting any blood clots. 
• Respiratory complications, such as pneumonia or difficulty breathing.  In rare 
cases, this may require you to be placed on a ventilator, a machine that assists in 
breathing, for a short period of time.   
• Heart complications, such as heart attack, irregular heart rhythm, or heart 
failure.  
• Ileus, which is a slowness of your intestine that may cause nausea or vomiting, 
may occur in 5-10% of cases.  Treatment may require a tube placed through your 
nose to help empty your stomach. 
 
Some of the questions in the quality of life questionnaire are of a personal nature and may be 
upsetting to some participants. Participants do not have to answer any questions that they do 
not want to answer. 
 
This study may involve unknown risks to an unborn or nursing child.  Women who are pregnant 
or nursing child may not participate in this study.   
 
The study records are considered confidential, but absolute confidentiality cannot be 
guaranteed. This study may result in presentations and publications, but steps will be taken to 
make sure participants are not identified by name. 
 
Potential Benefits: 
It is not possible to know if there will be any potential benefit beyond what is expected for 
treatment utilizing the standard of care. 
 
Potential Limitations: 
Based on our current data, there is a shorter length of stay with robotic hernia repair compared 
to open, even though the remaining outcome measures (SSO, SSI, recurrence, SSOPI, SSIPI, 
readmission) are similar, which may bias patients against opting into randomization.  This may 
not impact clinical outcomes, but could prolong the enrollment period.  Patients may also be 
biased in favor of, or against, robotic repair based on patients’ preconceived notion of either 
robotic or minimally invasive surgery.   
 
Participant withdrawal:  Participants may refuse to participate or choose to withdrawal from 
the study at any time without fear of being penalized or losing benefits.  Participants may be 

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withdrawn from the study at any time if it is in the study Physician’s judgment that withdrawal 
is in the participant’s best interest, if the participant’s medical condition changes or if the 
participant no longer follows the study instructions.   
 
Informed Consent:  The formal consent of a participant, using the GHS IRB approved informed 
consent form template, will be obtained by the study Physician before the participant 
undergoes any study procedures. The consent form will be signed and personally dated by the 
participant, a witness and the person who conducted the informed consent discussion. The 
original signed informed consent form will be retained in the participant’s study records. A 
photocopy of the informed consent form will be scanned into the electronic system at the 
Vascular Health Alliance office.  A photocopy of the signed informed consent form will be given 
to the participant for their records at the time of consent. 
 
Safety and Reporting:  Adverse Events, Serious Adverse Events and Unanticipated Adverse 
Device Effects will be reported to the GHS IRB according to OHRP policies 18.0 “Reporting of 
Unanticipated Problems Involving Risks to Subjects or Others and Adverse Events” and 40.0 
Appendices “Reportable Event Reporting Requirements - Appendix A.”  
 
Protocol Deviations:  Protocol Deviations will be reported to the GHS IRB according to OHRP 
policy 20.0 “Non-compliance with Regulations, IRB Policies, Procedures or Decisions.” 
 
Privacy and Confidentiality:  All data for this study will be kept confidential.   
 
Costs:  This study is not expected to yield any additional costs to participants.  Participants will 
not be compensated to participate in this study.   
 
References: 
 
1. Cobb WS, Warren JA, Ewing JA, et al. Open Retromuscular Mesh Repair of Complex Incisional 
Hernia: Predictors of Wound Events and Recurrence.Journal of the American College of 
Surgeons. Elsevier; 2015;220:606–613. 
2. Itani KMF, Hur K, Kim LT, et al. Comparison of laparoscopic and open repair with mesh for the 
treatment of ventral incisional hernia: a randomized trial.Arch Surg. 2010;145:322–8– 
discussion 328. 
3. Jin J, Rosen MJ. Laparoscopic versus open ventral hernia repair.Surg. Clin. North Am.; 
2008;88:1083–100– viii. 
4. Eker HH, Hansson BME, Buunen M, et al. Laparoscopic vs. open incisional hernia repair: a 
randomized clinical trial.JAMA Surg. 2013;148:259–263. 
5. Carter SA, Hicks SC, Brahmbhatt R. Recurrence and pseudorecurrence after laparoscopic 
ventral hernia repair: predictors and patient-focused outcomes.The American …. 2014. 

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6. Snyder CW, Graham LA, Gray SH, Vick CC. Effect of mesh type and position on subsequent 
abdominal operations after incisional hernia repair.Journal of the American …. 2011. 
7. Gray SH, Vick CC, Graham LA, et al. Risk of complications from enterotomy or unplanned 
bowel resection during elective hernia repair.Arch Surg. 2008;143:582–586. 
8. Abdalla RZ, Garcia RB, Costa R, Luca C. Procedimento de Rives/Stoppa modificado robô-
assistido para correção de hérnias ventrais da linha média.ABCD arq bras cir …. 2012. 
9. Millbourn D, Cengiz Y, Israelsson LA. Effect of stitch length on wound complications after 
closure of midline incisions: a randomized controlled trial.Arch Surg. 2009;144:1056–1059. 
10.  Warren JA, Cobb WS Ewing J, Carbonell AM. Prospective, observational, cohort study of 
robotic Rives-Stoppa retrorectus incisional hernia repair. Hernia . 2015;19(S1):S181