STRIDE: A Study of Patients With Lower Extremity Acute Limb Ischemia to Remove Thrombus With the Indigo Aspiration System
Conditions: Lower Extremity Acute Limb Ischemia, LE ALI
Sponsor: Penumbra Inc.

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STRIDE: A Study of Patients with Lower Extremity Acute 
Limb Ischemia to Remove Thrombus with the Indigo® 
Aspiration System 
Protocol 
CLP-15549.D 
Date of Protocol 
05/20/2021 
Device Name 
Indigo® Aspiration System 
Sponsor 
Penumbra, Inc. 
One Penumbra Place 
Alameda, CA 94502 
USA 

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TABLE OF CONTENTS 
1 
Introduction and Rationale .................................................................................................. 7 
 Disease State and Prevalence ........................................................................................................ 7 
 Current Treatments ....................................................................................................................... 7 
2 
Device Description ................................................................................................................ 8 
 Indigo® Aspiration System ............................................................................................................ 8 
 Indigo Aspiration Catheters and Separators ............................................................................... 9 
 Indigo® Aspiration System, CAT RX Aspiration Catheter, and SeparatorTM 4 .................... 10 
 Aspiration Tubing ........................................................................................................................ 11 
 Penumbra Aspiration Pump ....................................................................................................... 11 
 Penumbra Aspiration Pump Canister........................................................................................ 11 
3 
Risk Analysis ....................................................................................................................... 12 
 Risks Related to Aspiration Thrombectomy ............................................................................. 12 
4 
Study Overview ................................................................................................................... 13 
 Study Design ................................................................................................................................. 13 
 Study Objectives/Endpoints ........................................................................................................ 14 
4.2.1 
Primary Endpoints .............................................................................................................. 14 
4.2.2 
Secondary Endpoints .......................................................................................................... 14 
5 
Study Population ................................................................................................................. 14 
 Inclusion Criteria ......................................................................................................................... 14 
 Exclusion Criteria ........................................................................................................................ 14 
6 
Study Procedures ................................................................................................................ 15 
 Overview of Study Flow .............................................................................................................. 15 
 Study Visits ................................................................................................................................... 17 
 Recruitment and Screening ......................................................................................................... 17 
 Enrollment .................................................................................................................................... 17 
 Informed Consent ........................................................................................................................ 17 
 Baseline Evaluation ...................................................................................................................... 18 
 Procedure ...................................................................................................................................... 19 
6.7.1 
Preparation for Treatment ................................................................................................. 19 
6.7.2 
Medication during Intervention ......................................................................................... 19 
6.7.3 
Devices and Equipment ...................................................................................................... 19 
6.7.4 
Index Procedure .................................................................................................................. 21 
6.7.5 
Discharge and/or 7 days, whichever occurs first .............................................................. 21 
6.7.6 
30 Day Follow Up Visit (± 14 days) .................................................................................... 22 
6.7.7 
180 Day Follow Up Visit (± 30 days) .................................................................................. 22 
6.7.8 
365 Day Follow Up Visit (± 60 days) .................................................................................. 22 
7 
Investigator Responsibilities .............................................................................................. 24 
 Institutional Review Board / Ethics Committee Approval ....................................................... 24 
 Informed Consent ........................................................................................................................ 24 
 Adherence to Protocol/Amendments and Applicable Law ...................................................... 24 
 Case Report Form Completion ................................................................................................... 24 
 Image Upload ............................................................................................................................... 25 
 Reporting ...................................................................................................................................... 25 
7.6.1 
Adverse Events .................................................................................................................... 25 
7.6.2 
Analysis of Adverse Events................................................................................................. 26 
7.6.3 
Device Deficiencies .............................................................................................................. 27 
7.6.4 
Protocol Deviation ............................................................................................................... 27 
 Records Retention ........................................................................................................................ 28 
8 
Sponsor Responsibilities ..................................................................................................... 28 

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 Training ........................................................................................................................................ 28 
 Investigator List ........................................................................................................................... 28 
 Adverse Event Reporting ............................................................................................................ 29 
 Data Monitoring ........................................................................................................................... 29 
8.4.1 
Site Qualification Visit ........................................................................................................ 29 
8.4.2 
Site Initiation Visit .............................................................................................................. 29 
8.4.3 
Interim Monitoring Visit .................................................................................................... 29 
8.4.4 
Site Close Out Visit ............................................................................................................. 29 
 Data Management ........................................................................................................................ 29 
9 
Ethical Requirements ......................................................................................................... 30 
 Declaration of Helsinki ................................................................................................................ 30 
 Informed Consent ........................................................................................................................ 30 
 Subject Data Protection ............................................................................................................... 31 
10 Statistical Procedures ......................................................................................................... 31 
 General Statistical Considerations ............................................................................................. 31 
 Sample Size Estimation for the Primary Outcome ................................................................... 31 
 Control of Systematic Error and Bias ........................................................................................ 31 
 Missing Data and Imputation Methods ..................................................................................... 31 
 Definition of Populations ............................................................................................................. 32 
10.5.1 Screened ............................................................................................................................... 32 
10.5.2 Screen Failure ...................................................................................................................... 32 
10.5.3 Enrolled ................................................................................................................................ 32 
10.5.4 Completed ............................................................................................................................ 32 
10.5.5 Early Termination ............................................................................................................... 32 
 Definition of Analysis Populations ............................................................................................. 32 
10.6.1 Intent to Treat Sample ........................................................................................................ 32 
 Interim Analysis ........................................................................................................................... 32 
 Statistical Analysis of Primary Endpoint................................................................................... 33 
 Secondary Statistical Analysis .................................................................................................... 33 
 Analysis of Adverse Events ..................................................................................................... 33 
 Baseline Characteristics .......................................................................................................... 33 
 Pooling Across Centers ........................................................................................................... 33 
 Final Report ............................................................................................................................. 34 
11 Study Committees and Core Labs ..................................................................................... 34 
 Imaging Core Lab ........................................................................................................................ 34 
12 Study Administration ......................................................................................................... 34 
 Stopping the Study Based on Interim Safety Data .................................................................... 34 
 Clinical Study Termination/Withdrawal ................................................................................... 34 
 Missing Visits ................................................................................................................................ 35 
 Protocol Adherence and Amendments ....................................................................................... 35 
 Study Registration ....................................................................................................................... 35 
13 Publication of Information ................................................................................................. 35 
14 Contact Information ........................................................................................................... 37 
15 References ............................................................................................................................ 38 
16 APPENDIX I: Definitions and Classifications ................................................................. 40 
 Definitions ..................................................................................................................................... 40 
 Acronyms ...................................................................................................................................... 41 
17 APPENDIX II: Classifications and Scales ........................................................................ 42 
 Rutherford Classification for Acute Limb Ischemia 18, 19 ......................................................... 42 
 Fontaine Classification 18 ............................................................................................................. 42 

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 Modified SVS Runoff Score 20 ..................................................................................................... 43 
 TASC II Aortoiliac Lesion Classification 20 ............................................................................... 43 
 TASC II Femoral-Popliteal Lesion Classification 20 ................................................................. 44 
 TIMI Flow 21 ................................................................................................................................. 44 
 Vascular Quality of Life – 6 22 ..................................................................................................... 45 
 
 
 

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1 
Introduction and Rationale 
 Disease State and Prevalence 
Acute limb ischemia (ALI) is a vascular emergency characterized by a sudden loss of 
arterial perfusion in the lower limbs.1-3 The condition affects an estimated 15-26 patients 
/ 100,000 persons / yr in the United States1, and is associated with extremely high 
morbidity and mortality rates. In the UK, a study calculated an annual ALI incidence of 
10 in 100,000, with 5-year survival rates for avoiding amputation at 36.7% and overall 
at 55.9%.4  
Mortality at 1 yr can reach 40%1, 5 and post-procedural rates of limb loss are reported in 
between 12%-50% of cases.5 Optimal clinical outcomes therefore necessitate urgent 
recognition of the condition and prompt restoration of arterial blood flow, in order to 
avoid irreversible ischemia and to support limb salvage.2, 3  
In ALI, the rapid onset of perfusion limitation (<14 days) threatens limb viability due to 
insufficient time for adequate collateral recruitment.6 Clinical diagnosis depends on 
symptom presentation, which includes the ‘6P’s’: pain, pallor, pulse deficit, paresthesia, 
poikilothermia, and paralysis of the affected limb.6, 7 Nevertheless, uncertainty remains 
regarding interventional outcomes for ALI patients, and despite recent improvements in 
therapeutic technique and declines in 1-yr amputation rate, there have been no significant 
improvements in 1-yr amputation-free survival, which remains unchanged at 52.3%.1, 5 
 
Current Treatments 
Clinical practice recommendations for the diagnosis and management of ALI classify 
patients using the Rutherford classification scale.2, 3, 8, 9 Patients falling into Rutherford 
category I present with no continuing ischemic pain and the limb is not immediately 
threatened. 8, 10 Patients falling into Rutherford category II (a and b) are at risk of limb 
loss, with prompt treatment and revascularization urgently indicated for limb salvage. 
 
Contemporary revascularization guidelines for ALI include, but are not limited to, 
catheter-directed thrombolysis (CDT), percutaneous thrombo-aspiration, and surgical 
thromboembolectomy.2, 3 Over the past decades, the surgical management of ALI has 
evolved to include endovascular approaches,5, 9 especially following the publication of 
three randomized, multicenter trials which established the efficacy of catheter-directed 
thrombolysis (CDT) as compared with surgical revascularization.10-12 CDT,13 along with 
newer endovascular approaches including aspiration thrombectomy, have become 
routine for restoring perfusion in ALI patients in the Rutherford I and II categories.3, 5, 10 
Nevertheless, the cost of ALI-related complications and mortality remains high, leading 
to strong interest in assessing the efficacy of different revascularization devices and 
procedures.14  
 
The PEARL registry evaluated 283 patients (mean age 65±13years) from 34 institutions 
across the US which tracked the use of rheolytic pharmacomechanical thrombectomy 
(PMT) to manage ALI.9 This method generates low-pressure suction to remove occlusive 
lesions. At 12-month follow-up, amputation-free survival and freedom from mortality 
was 81% and 91%, respectively. This study supported the use of PMT, as a first-line 

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treatment for ALI, with reduced procedure times and an acceptable risk profile compared 
with CDT.9 
 
Although CDT remains an established technique for ALI treatment, it can be associated 
with multiple procedures and hemorrhagic complications.15 A small 2018 study 
comparing percutaneous aspiration thrombectomy (PAT) (n=15) versus conventional 
CDT (n=27) in treating noniatrogenic acute lower limb ischemia, found that first-line use 
of PAT for endovascular treatment of ALI could reduce the need for CDT, without 
significantly increasing costs.15  
 
PRISM, a multicenter retrospective case analysis, was established to determine the safety 
and initial efficacy of another aspiration–based extraction technique (XTRACT), for 
treating peripheral arterial thromboembolism using the Penumbra/ Indigo System.16 
Seventy-nine patients (median age 69 years [IQR], 60–78 years) with peripheral 
occlusions were enrolled treated with XTRACT as the initial therapy or secondary 
therapy. Complete or near-complete revascularization (TIMI grade 2/3) was achieved in 
79.5% of patients who received Indigo as a frontline treatment and successful 
revascularization was achieved in 92.5% of patients who received aspiration-based 
therapy as salvage or secondary therapy.16 Complete flow restoration (TIMI grade 3) was 
successfully achieved in 77.2% of patients, and no patients required surgical 
revascularization. No device-related adverse events occurred, establishing the safety and 
efficacy of using the Penumbra/ Indigo system for aspiration-based extraction of acute 
peripheral arterial occlusions.16 
 
The goal of this study protocol is to create a framework for a prospective, multi-center 
study to  obtain additional clinical evidence for the Indigo System as the frontline PAT 
approach for ALI patients in the Rutherford I, IIa and IIb categories, for whom immediate 
treatment and revascularization can maintain limb viability and prevent limb loss. Rapid 
restoration of arterial flow is crucial. The FRIENDS registry (n=200) showed that delays 
in treatment of limb ischemia is associated with poorer outcomes in ALI patients, 
including much higher rates of first amputation (p=0.0002) and worse amputation-free 
survival rates (p<0.05).17 Given the high cost burden and poor clinical outcomes 
associated with ALI, this registry will provide much-needed clinical data on restoring 
vessel patency and improving patient morbidity and mortality rates. 
 
2 
Device Description 
 Indigo® Aspiration System  
General Description/Overview 
The Indigo Aspiration System is comprised of several devices: 
• Indigo Aspiration Catheter 
• Penumbra Aspiration Pump 
• Indigo Pump/Canister Tubing 
• Indigo Aspiration Tubing 
• Indigo Separator™ 
 

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The Indigo Aspiration System is designed to remove thrombus from the vasculature using 
continuous aspiration. The Indigo Aspiration Catheter targets aspiration from the pump 
directly to the thrombus. The Indigo Separator may be used to clear the lumen of the 
Indigo Aspiration Catheter should it become blocked with thrombus. The use of the Indigo 
Separator may not be necessary when using an Indigo Aspiration Catheter with an I.D. of 
0.054 in [1.37 mm] or larger. The Indigo Aspiration Catheter is introduced through a guide 
catheter or introducer sheath and into the peripheral vasculature and guided over a 
guidewire to the site of the primary occlusion. The Indigo Aspiration Catheter is used with 
the Penumbra Aspiration Pump to aspirate thrombus from an occluded vessel. As needed, 
an Indigo Separator may be deployed from the Indigo Aspiration Catheter to assist with 
thrombus removal. The Indigo Separator is advanced and retracted through the Indigo 
Aspiration Catheter at the proximal margin of the primary occlusion to facilitate clearing 
of the thrombus from the Indigo Aspiration Catheter tip. For the aspiration source, the 
Indigo Aspiration Catheter is used in conjunction with the Penumbra Aspiration Pump, 
which is connected using the Indigo Aspiration Tubing and the Indigo Pump/Canister 
Tubing. The Indigo Aspiration Catheter is provided with a steam shaping mandrel and 
rotating hemostasis valve, and a peelable sheath. The Indigo Separator is provided with 
an introducer and torque device. The devices are visible under fluoroscopy.  
 
The Indigo Aspiration System received original US Food and Drug Administration (FDA) 
510(k) clearance for the peripheral arterial indication in September 2012 under K121917. 
In May 2015 under K142870 the indication was expanded to the peripheral arterial and 
venous indication and is currently available in the United States. The Indigo Aspiration 
System received original CE mark on 18 September 2014 under Registration Number 
252.943 and is currently available in Europe. 
 
 
Indigo Aspiration Catheters and Separators 
As part of the Indigo Aspiration System, the Indigo Aspiration Catheters and Separators 
are indicated for the removal of fresh, soft emboli and thrombi from vessels of the 
peripheral arterial and venous systems.  
 
Indigo Aspiration Catheters and Separators are made of biocompatible materials 
commonly utilized for interventional devices. The Aspiration Catheter is provided sterile 
for single use and may be packaged in a kit with the Aspiration Tubing. The kit also 
contains a rotating hemostasis valve (RHV) and an introducer sheath.   
 
Figure 1: Assembled Aspiration System with Indigo Separator 
 
 

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Indigo® Aspiration System, CAT RX Aspiration Catheter, and SeparatorTM 4 
As part of the INDIGO Aspiration System, the INDIGO CAT RX Aspiration 
Catheters and INDIGO Separator 4 are indicated for the removal of fresh, soft 
emboli and thrombi from vessels in the coronary and peripheral vasculature. 
 
General Description/Overview 
The Indigo™ Aspiration System is comprised of several devices, which will be available 
based on applicable regulatory approvals for commercialization: 
• Indigo CAT RX Aspiration Catheter 
• Indigo Separator™ 4 
• Indigo Aspiration Tubing 
• Indigo Pump Canister/Tubing 
• Penumbra Aspiration Pump 
 
The Indigo Aspiration System is designed to remove thrombus from the vasculature using 
continuous aspiration. The Indigo CAT RX Aspiration Catheter is a dual lumen rapid 
exchange catheter that targets aspiration from the Pump directly to the thrombus, 
removing it via the Indigo Aspiration Tubing and depositing it in the Pump Canister. The 
Indigo Separator 4 may be used, if needed, to clear the lumen of the Indigo CAT RX 
Aspiration Catheter should it become blocked with thrombus. The Indigo CAT RX 
Aspiration Catheter is introduced through a guide catheter or long introducer sheath into 
the coronary or peripheral vasculature and guided over a guidewire to the site of the 
primary occlusion. The Indigo CAT RX Aspiration Catheter may be provided with a 
rotating hemostasis valve and a peelable sheath. The Indigo Separator 4 is provided with 
an introducer and torque device. The Indigo CAT RX Aspiration Catheter and Indigo 
Separator 4 are visible under fluoroscopy.  
 
The Indigo CAT RX Aspiration Catheter, including the Separator 4 and the Aspiration 
Tubing, received US Food and Drug Administration (FDA) 510(k) clearance in May 2017 
under K163618 and is currently available in the United States.   
The Indigo CAT RX Aspiration Catheter, including the Separator 4 and the Aspiration 
Tubing may be used in other regions of the world as soon as applicable commercialization 
regulatory approvals are obtained. 
 
Figure 2: Assembled Aspiration System with Indigo CAT RX and SeparatorTM 4 
 
 
 

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 Aspiration Tubing 
As part of the Indigo Aspiration System, the Indigo Sterile Aspiration Tubing is indicated 
to connect the Indigo Aspiration Catheters to the Penumbra Aspiration Pump.  
 
Lightning Aspiration Tubing is an additional component of the Indigo Aspiration System, 
which received original US Food and Drug Administration (FDA) 510(k) clearance in 
March 2020 under K193244 and is currently available in the United States. 
The Lightning Aspiration Tubing may be used in other regions of the world as soon as 
applicable commercialization regulatory approvals are obtained. 
 
Lightning Aspiration Tubing is designed to serve as a conduit to assist in thrombus 
removal and restoration of blood flow in the peripheral vasculature. Lightning facilitates 
the transfer of vacuum between the Aspiration Catheter and Penumbra Aspiration Pump 
while providing intermittent or continuous aspiration. Intended users for this device are 
physicians who have received appropriate training in surgical procedures and/or 
interventional techniques. 
 
During scenarios when occlusion is detected (e.g. blood clot is engaged with an Indigo 
Aspiration Catheter), Lightning allows for continuous aspiration through the Indigo 
Aspiration Tubing. During scenarios when no occlusion is detected, Lightning is designed 
to minimize aspirated blood volume by converting to intermittent aspiration.  
 
Consistent with the existing Indigo Aspiration Tubing, the operator/physician will be able 
to maintain manual control of flow via a flow control switch which will completely stop 
flow when in the “OFF” position. 
 
Figure 2: Lightning Aspiration Tubing 
 
 
 
 
 Penumbra Aspiration Pump 
The Penumbra Aspiration Pump is indicated as a vacuum source for Penumbra Aspiration 
Systems.  
 
 Penumbra Aspiration Pump Canister 

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A 1000 ml minimum canister with a stemmed lid is designed for use with the Pump. Each 
canister has a stop-flow filter to prevent excess fluid from entering the Pump Canister 
Tubing. The patient port on the lid is sized to accept the Suction Connector on the 
Aspiration Tubing. Graduations are placed on the canister in 50-ml and 100-ml 
increments. The canister lid is removable. 
 
For the Pump MAX, Pump Canister Tubing is used to connect the Pump to the Pump 
Canister. This tubing has an inline filter to prevent fluid and contaminants from entering 
the pump. The tubing lumen remains open under full vacuum. The Penumbra ENGINE 
does not require this additional tubing. The Suction Connector is securely attached to the 
Pump Canister lid and Pump via press fit. 
 
Further detailed description of all the devices listed in this protocol can be found within 
their respective Instructions For Use (IFU).  
 
3 
 Risk Analysis 
A thorough risk analysis was performed as part of design control requirements of the Quality 
System Regulation (21 CFR 820) and risk management activities were performed in 
accordance with ISO 14971 
 Risks Related to Aspiration Thrombectomy 
It is anticipated that the treatment risks associated with the Indigo Aspiration System 
devices for removal of fresh, soft emboli and thrombi from vessels of the peripheral 
arterial and venous systems are unchanged since market introduction. In terms of the 
clinical risk, adverse events that may be associated with the use of the Indigo Aspiration 
System or with interventional procedures include, but may not be limited to: 
 
• allergic reaction and anaphylaxis   from contrast media 
• acute occlusion 
• air embolism 
• arteriovenous fistula 
• death 
• device malfunction 
• distal embolization 
• emboli 
• false aneurysm formation 
• hematoma or hemorrhage at access site 
• inability to completely remove thrombus 
• infection 
•  hemorrhage 
•  ischemia 
•  kidney damage from contrast media 
•  neurological deficits including stroke 
•  vessel spasm, thrombosis, dissection, or perforation 
•  intimal disruption 

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•  myocardial infarction 
•  emergent surgery 
•  fibrillation 
•  hypotension 
•  respiratory failure 
•  peripheral thromboembolic events 
 
Risks that may be associated with the Lightning Aspiration Tubing include, but may not be 
limited to: 
• allergic reaction and anaphylaxis 
from contrast media 
• acute occlusion 
• air embolism 
• arrhythmia/fibrillation 
• arteriovenous fistula 
• death 
• device malfunction 
• distal embolization 
• emergent surgery 
• false aneurysm formation 
• hematoma, hemorrhage, or blood 
loss at access site 
• hematoma, hemorrhage, or blood 
loss  
• hypotension 
 
• inability to completely remove 
thrombus or control blood flow 
• infection 
• ischemia 
• kidney damage from contrast 
media 
• myocardial infarction 
• neurological deficits including 
stroke 
• respiratory failure 
• thromboembolic events 
• vascular complications (including 
vessel spasm, thrombosis, intimal 
disruption, dissection, or 
perforation) 
 
 
Considerable testing has been completed to ensure that the Indigo Aspiration System does 
not pose a significant risk. Safety of the Indigo Aspiration System has been demonstrated 
through extensive pre-clinical testing in both bench-top and in vivo models. Critical 
design characteristics were evaluated to ensure that system components can withstand the 
rigor of clinical use. A thorough risk analysis was performed as part of design control 
recommendations of the Quality System Regulation (21 CFR 820). Risk management 
activities performed in accordance with ISO 14971did not identify any different risks or 
risk levels compared to other currently marketed devices.  
 
A list of all anticipated adverse events is listed in the IFU for each device. 
 
4 
 Study Overview 
The intent of this study is to collect safety and performance data on Indigo Aspiration System 
in a patient population with LE ALI. 
 
 Study Design 

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STRIDE is a post-market, real world, prospective, single-arm, multi-center study looking 
at patients that present with LE ALI who are eligible for mechanical thrombectomy using 
the Indigo Aspiration System. Up to 130 subjects at up to 25 sites globally will participate. 
 Study Objectives/Endpoints 
4.2.1 Primary Endpoints 
• Target limb salvage rate at 1-month post-procedure  
4.2.2 Secondary Endpoints 
• Technical success defined as TIMI 2/3 flow rate immediate post-procedure  
• Modified SVS runoff score immediate post-procedure as compared to 
baseline 
• Improvement of Rutherford classification of one or more as compared to 
the pre-procedure  
• Patency at 1 month 
• Target limb salvage rate at 12 months post-procedure 
• Rates of device related serious adverse events (SAEs)  
• Major bleeding peri-procedure  
• Mortality at 12 months 
 
5 
 Study Population 
 Inclusion Criteria 
1. Patient age ≥ 18  
2. Patient presents with acute (≤14 days) occlusion of lower limb artery(ies) 
(below inguinal ligament)  
3. Patient with a Rutherford Category I, IIa or IIb score 
4. Frontline treatment with Indigo Aspiration System  
5. Informed consent is obtained from either patient or legally authorized 
representative (LAR) 
 
 Exclusion Criteria 
1. Life expectancy <1 year  
2. Target vessel size <2 mm 
3. LE ALI secondary to dissections, vasculitis and/or target vessel trauma 
4. Amputation in the ipsilateral limb 
5. Pregnancy or positive pregnancy test according to site specific standards of care 
(only required for women of childbearing potential, serum or urine acceptable) 
6. Absolute contraindication to contrast administration 
7. Patient is unwilling or unable to comply with protocol follow up schedule 
and/or based on the Investigator’s judgment the patient is not a good study 
candidate 

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8. Currently participating in an investigational drug or device clinical trial that 
may confound the study endpoints. Patients in observational, natural history, 
and/or epidemiological studies not involving intervention are eligible. 
9. Target thrombus in a saphenous vein bypass graft 
6 
Study Procedures 
 Overview of Study Flow 
Patients presenting with LE ALI should be assessed for eligibility. All sites will keep a 
screen failure log of all potential study candidates who are screened and not enrolled or 
screened, consented, and not enrolled. Reason(s) for exclusion will be recorded. Screening 
information, including screen failures, will be reported in Electronic Data Capture system 
(EDC).  
Recruitment rates will be tracked over time for each site. The actual recruitment rates will 
be useful for planning further clinical studies and determining the widespread impact of 
the therapy. 
 
 

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Figure 1: Study Flow  
 
 
 
 
 
 

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 Study Visits 
Subjects enrolled in this study will follow the visit schedule below and will continue to 
receive routine practice/standard of care treatment at each follow up visit. Procedure is 
Day 0 for determining follow up visit dates.  
1. Baseline Evaluation 
2. Procedure (Day 0) 
3. Discharge and/or 7 Days, whichever occurs first  
4. 30 Day Follow-Up (± 14 days) 
5. 180 Day Follow-Up (± 30 days) 
6. 365 Day Follow-Up (± 60 days) 
 Recruitment and Screening 
The target population are subjects ≥18 years of age who are presenting with LE ALI. No 
study specific screening tests or procedures are required for enrollment in the study. 
Standard of care evaluations will be used to confirm eligibility. 
Potential study participants and/or the subjects’ representative (e.g. LAR, next of kin, 
family member, etc.)  will be identified by the study team at each site to obtain consent 
and determine eligibility.   
 Enrollment 
Patients will be considered enrolled once informed consent is obtained per Institutional 
Review Board (IRB)/Ethics Committee (EC), the Indigo Aspiration Catheter has been 
inserted into the body as frontline treatment, and all eligibility is confirmed. Patients who 
fail to meet entry criteria will be considered a screen fail. 
All follow-up visits will be conducted based on date of procedure, regardless of enrollment 
date. 
 Informed Consent  
The Investigator or designee will obtain written informed consent from the subject or the 
subjects’ representative (e.g. LAR, next of kin, etc.) using the current Institutional Review 
Board (IRB)/Ethics Committee (EC) approved consent form per IRB/EC policy.  
For sites in North America, patients who have had a procedure (using the Indigo 
Aspiration System with the Indigo Aspiration Catheter as frontline)  and all eligibility is 
confirmed, may be consented up to 2 calendar days post-procedure but prior to initial 
discharge, and enrolled in the study. The point of enrollment is defined as the date of 
informed consent or introduction of the Indigo Aspiration Catheter, whichever occurs 
later.  
For sites in Europe, the informed consent process will be applied per local Ethics 
Committee approvals. 
All informed consent documents used under this protocol will be consistent with 
applicable elements of Good Clinical Practice (ICH E6), ISO 14155,Clinical investigation 

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of medical devices for human subjects – Good Clinical Practice (GCP), FDA 21 CFR Part 
50 Protection of Human Subjects, and  will be approved by the site’s reviewing IRB/EC 
prior to study initiation.  
Any modification to the sample informed consent form made by the study site must be 
approved by the Sponsor and the IRB/EC before use. Each study site will provide the 
Sponsor with a copy of the IRB/EC approved consent forms. Informed consent completion 
will be monitored regularly by the Sponsor.  
 Baseline Evaluation 
Subjects will be clinically evaluated in the same manner as any patient presenting with 
LE ALI. The medical history screen, available clinical exams obtained, and imaging 
information per institutional routine care will be evaluated to determine patient eligibility. 
Medication, standard of care lab values, and duplex ultrasound will be recorded.  
 
Patients will be screened against study eligibility criteria during standard clinical practice. 
A signed study-specific IRB/EC-approved informed consent form (ICF) must be obtained 
from each potential subject (or the subjects’ representative (e.g. LAR, next of kin, family 
member, etc.)) before performing any test that goes beyond standard clinical care.  
 
These exams were chosen on the basis of their reliability, familiarity to the endovascular 
community, and comparability to other trials of LE ALI. All scores will be recorded in 
source documentation and entered into the electronic case report forms (eCRFs). 
 
• Ankle-Brachial Index: ABI is a diagnostic test used to compare the systolic 
blood pressure at the ankle with the systolic blood pressure measured in the 
arm to gauge circulation.  
• Rutherford Classification for LE ALI characterizes the acute presentation of 
patient clinical symptoms with objective findings, including arterial and 
venous Doppler signals (see APPENDIX II: Classifications and Scales). 
• Vascular Quality of Life Questionnaire-6: VascuQoL-6 is a valid health-
related quality of life questionnaire developed for use in peripheral arterial 
disease (see APPENDIX II: Classifications and Scales) 
 
Baseline assessments will be performed, but not limited to the following: 
1. Demographics 
2. Confirm eligibility  
3. General medical history 
4. Pregnancy test (only required for women of childbearing potential) 
5. Vital signs 
6. Rutherford Classification 
7. Ankle-Brachial Index (ABI) 
8. Duplex Ultrasound (DUS), Computed Tomography Angiography (CTA), 
or Magnetic Resonance Angiography (MRA): will provide an initial 
diagnosis of LE ALI per institutional routine care  
9. Medication review  

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10. VascuQoL-6  
11. Laboratory Assessments as part of standard of care (SOC) (most recent 
results obtained within 30 days prior to index procedure are permitted as 
baseline data) 
a. INR, PT, aPTT/PTT, Platelets, WBC, RBC, Hgb, Hct, Creatinine, 
Glucose, BUN 
b. Additional SOC labs may be collected, if available 
 
 Procedure  
All procedures will be conducted in accordance with standard of care guidelines for 
treatment of patients with LE ALI at each participating hospital. The procedure will occur 
after completion of baseline, clinical assessments, and pre-procedural imaging. The Indigo 
Aspiration System with the Indigo Aspiration Catheter must be used as frontline 
treatment.  
6.7.1 Preparation for Treatment  
All physicians will follow routine site practice guidelines to determine patient 
eligibility for the procedure.  
6.7.2 Medication during Intervention  
Any medical therapy necessary for patients with LE ALI should be used in 
accordance with the routine, standard of care guidelines at the study site.  
 
6.7.3 Devices and Equipment  
The follow devices/equipment will be used in addition to the standard devices used 
per site routine standard of care.  
 
Please refer to the device description Section 2.0 for complete details. 
 
 

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6.7.4 Index Procedure 
Subjects enrolled in the study should receive the SOC procedural care for LE ALI. 
At a minimum, the following information will be collected during Index Procedure, 
but not limited to: 
1. Initial (pre-procedure) 
a. The following assessments will be administered before the 
Indigo Aspiration System and Aspiration Catheter is used:  
• Angiography: performed to assess procedure data 
points including the modified SVS runoff score.  
• Modified SVS runoff score: calculated using the 
angiogram by assessing the patency and degree of 
stenosis/occlusion in the popliteal artery and the three 
tibial vessels17  
2. Target lesion characteristics  
3. After Indigo Aspiration is complete (which can be considered Final if 
adjunctive procedures are not required) the following assessments will 
be administered, but not limited to:  
a. Angiography  
b. Modified SVS runoff score 
c. TASC II score, if applicable 
4. Final (after all adjunctive procedures are complete)  
a. Angiography   
b. Modified SVS runoff score 
5. Procedural details including key procedural timepoints 
6. Adjunctive procedure(s) 
7. Adverse event review 
8. Medication review 
9. Device deficiencies 
 
Angiography should be uploaded per section 7.5 Image Upload. 
 
6.7.5 Discharge and/or 7 days, whichever occurs first 
Information will be collected during discharge and/or 7-day visit, (within 1 day 
prior to discharge or at day 7, whichever occurs first), but not limited to the 
following: 
1. Vital signs 
2. Rutherford classification 
3. ABI 
4. Adverse event review 
 
In addition to the assessments above, the following will be collected at discharge:  
1. The location that the subject is discharged to and the date of discharge  
2. If any adverse events occurred, it will be reported on the Adverse Event 
Form 

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3. Details of each hospital unit that the subject was admitted to during the 
index admission will be recorded 
4. Medication use 
6.7.6 
30 Day Follow Up Visit (± 14 days) 
Information will be collected during the 30-day follow up visit, but not limited to 
the following: 
1. Vital signs 
2. Rutherford classification 
3. DUS, CTA, or MRA 
4. ABI 
5. VascuQoL-6 
6. Medication review 
7. Adverse event review 
 
6.7.7 180 Day Follow Up Visit (± 30 days) 
Information will be collected during the 180-day follow up visit, but not limited to 
the following: 
1. Vital signs 
2. Rutherford classification 
3. DUS, CTA or MRA 
4. ABI 
5. VascuQoL-6 
6. Medication review 
7. Adverse event review 
6.7.8 365 Day Follow Up Visit (± 60 days) 
Information will be collected during the 365-day follow up visit, but not limited to 
the following: 
1. Vital signs 
2. Rutherford classification 
3. DUS, CTA, or MRA 
4. ABI 
5. VascuQoL-6 
6. Medication review 
7. Adverse event review 

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7 
Investigator Responsibilities 
 Institutional Review Board / Ethics Committee Approval 
Prior to enrolling patients into the study, the Investigator will ensure that proper IRB/ EC 
approval is obtained in accordance with applicable local laws and regulations.  The 
IRB/EC shall approve all study documents as appropriate, including but not limited to the 
final protocol, amendments to the protocol, IFU (where applicable), and the informed 
consent, per FDA 21 CFR part 56; Institutional Review Boards or applicable EC 
requirements. The investigator should keep the IRB/EC informed of any serious adverse 
event, or serious device defects as per their policy. 
The Investigator will report to the Sponsor or designee immediately if the approval to 
conduct the investigation is withdrawn by the IRB/EC or Competent Authority as 
required. The report will include a complete description of the reason(s) for which 
approval was withdrawn. 
 Informed Consent 
The Investigator is responsible for ensuring that completed informed consent is obtained 
in accordance with Section 6.5 of this protocol and according to country and local 
requirements prior to conducting any study-related assessments prior to enrollment of 
patients in the study. 
 Adherence to Protocol/Amendments and Applicable Law 
The Investigator is responsible for overseeing, ensuring that the study is conducted, and 
completing the study according to this protocol and in accordance with the relevant 
aspects of ISO 14155, 21 CFR 50, 54, and 56, Declaration of Helsinki, along with any 
conditions imposed by the reviewing IRB/EC, and all other applicable regulations. The 
Investigator shall approve and adhere to this protocol and any amendments that arise 
during the course of the study. The Investigator has overall responsibility of the conduct 
of this study including oversight of all delegated individuals, tasks and all activities 
conducted under this protocol pursuant to FDA 21 CFR part 820 and Investigator 
responsibilities. 
It is the Investigator’s responsibility to ensure that the Institution’s staff assisting with the 
study have the appropriate qualifications, are fully instructed on the study procedures, and 
will respect study confidentiality.  
 Case Report Form Completion 
The Investigator and study staff shall complete the eCRFs associated with this study. 
Subject numbers shall be used to identify individual participants in this study. The eCRFs 
should be a complete and accurate record of subject data collected during the study 
according to relevant aspects of ISO 14155, FDA 21 CFR 11, Electronic Records; 
Electronic Signatures and GCP requirements. It is the Investigator's responsibility to 
ensure the quality of the data collected and recorded is appropriate and collected in 
accordance with GCP and all applicable regulations. Data entry will be performed by the 
investigational site(s). Investigators are responsible for completion and timely submission 

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of data to Penumbra, Inc. Every reasonable effort should be made to complete data entry 
within 7 business days of data collection. 
 Image Upload  
Sites will be provided with instructions for how image timepoints should be collected and 
submitted within 14 days of the acquisition of the required imaging. If the site is unable 
to provide the images within this time frame, the appropriate Sponsor contact should be 
notified.  
Angiography will be uploaded to an image management system for Core Lab review. 
Instructions for image collection and upload will be provided. Study staff shall ensure that 
no images contain any personally identifying information about the subject or study site 
(e.g. Physician name, Institution name, patient name, etc.). 
 Reporting 
The Investigator will be responsible for reporting the following: 
7.6.1 Adverse Events 
Adverse events (AE) must be recorded by the Investigator on the eCRFs and will be 
monitored during the entire study. All SAEs and procedure and device related AEs 
will be collected starting at Day 0 through final follow up for enrolled subjects. 
Additionally, bleeding complications should be reported.  
Minimum requirements of data to be recorded are: event term, event start date, 
seriousness, action taken, outcome and device-relatedness or causality. 
In order to ensure prompt reporting of AEs, all reportable AEs (as well as all related 
study data) are required to be entered into the EDC in a timely manner. Any 
suspected Unanticipated Adverse Device Events (UADEs)/ Unanticipated Serious 
Adverse Device Effects (USADE) should be reported immediately by calling the 
Sponsor. All device related Serious Adverse Events (SAEs) should be reported in 
the EDC within 72 hours of the site staff first being made aware of the occurrence 
of the SAE. If the EDC is unavailable, an email can be sent to Penumbra.  
The Investigator must report adverse events to the IRB/EC according to local 
requirements. The Investigator is responsible for reporting time frames and 
complying with local or national requirements.  In addition, the Investigator will 
report to the sponsor and IRB/EC any device malfunctions that could have led to a 
SAE, if required by national regulations or by local authorities. 
For the purpose of reporting within this protocol, pre-existing conditions or planned 
procedures for pre-existing conditions are not reportable as AEs unless there is 
worsening of the condition with an increase in severity or frequency during the 
course of the study. All deaths will be reported regardless of causality. When 
reporting a death, the primary condition or diagnosis that contributed to the fatal 
outcome should be reported as a SAE with an outcome of death. Only a single cause 

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of death should be reported in EDC. If the cause of death is unknown, report 
“unknown cause of death” as a SAE.  
7.6.2 Analysis of Adverse Events 
A Sponsor Medical Monitor will review the pre-defined categories of 
adverse events as they are reported throughout the duration of the study. The 
Sponsor Medical Monitor will collect redacted source documents and review 
adverse events. 
7.6.2.1 Definitions 
• Adverse Event (AE): Any undesirable clinical event occurring in a patient 
during a clinical trial, whether or not it is considered related to the study 
device or whether anticipated or unanticipated.  This includes a change in a 
patient's condition or laboratory results that has or could have a deleterious 
effect on the patient's health or well-being or untoward clinical sign in users 
or other persons related to use of medical device.  
• Adverse Device Effect (ADE): An adverse event related to the use of the 
study medical device.  
• Definition of SAE  
A SAE is an event that: 
o Led to death  
o Led to a serious deterioration in the health of the patient that: 
− Resulted in life-threatening illness or injury  
− Resulted in chronic disease 
− Resulted in permanent impairment of a body structure or a 
body function  
− Required in-patient hospitalization or prolongation of 
existing hospitalization  
− Resulted in medical or surgical intervention to arrest 
permanent impairment to body structure or a body function  
− Led to fetal distress, fetal death or a congenital abnormality 
or birth defect 
 
• Unanticipated Adverse Device Event (UADE): An unanticipated adverse 
device effect is any serious adverse effect on health or safety or any life-
threatening problem or death caused by, or associated with, a device, if that 
effect, problem, or death was not previously identified in nature, severity, 
or degree of incidence in the   current risk assessment.  
7.6.2.2 Relationship to the Study Device 
An AE is considered to be device-related when it is reasonable to believe that 
the event may have been caused by or is related to the device. The following 

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definitions will be used to assess the relationship of the adverse event to the use 
of study device.  
• 
Definite:  The temporal sequence is relevant and the event abates upon 
device application completion/removal, or reappearance of the event on 
repeat device application 
• 
Probable:  The temporal sequence is relevant or the AE abates upon 
device application completion/removal or the AE cannot be reasonably 
explained by the subject’s condition or comorbidities.  The AE is related 
or most likely associated with the device 
• 
Possible: The temporal sequence between the device and the AE is such 
that the relationship is not unlikely or there is no contradicting evidence 
that can reasonably explain the subject’s condition.  There is a possibility 
of a relationship between the AE and the device 
• 
Unrelated:  The AE is not associated with the device.  There is no relation 
between the AE and the device 
Similar grading will be used for assessing the relationship to index procedure 
and to index LE ALI.   
7.6.3 Device Deficiencies  
All device deficiencies related to the identity, quality, durability, reliability, safety 
or performance of the study device shall be documented and reported through the 
standard commercial process and within the EDC. Investigators must report all 
possible device deficiencies associated with the device observed during the study. 
This includes unexpected outcomes or device deficiencies that might have led to a 
serious adverse event if a) suitable action had not been taken or b) intervention has 
not be made or c) if circumstances had been less fortunate.  
Device manufacturers are required to report qualifying medical device incidents to 
the relevant national competent authorities. An incident is defined as “any 
malfunction or deterioration in the characteristics and/or performance of a device, 
as well as any inadequacy in the labeling or the instructions for use which, directly 
or indirectly, might lead to or might have led to the death of a subject or to a serious 
deterioration in their state of health.” A deterioration in state of health is not 
considered unanticipated if the condition leading to the event was considered in a 
risk analysis.  
7.6.4 Protocol Deviation 
Deviations defined in this protocol should be clearly documented, if identified 
during monitoring or through other means.  For this study, deviations should be 
reported for the following categories:  

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• 
Inclusion/exclusion criteria deviation(s) 
• 
Informed consent deviation(s) 
 Records Retention 
The Investigator shall maintain the records associated with this study for a period as 
defined by local regulations A Trial Master File (TMF) will be used as the master 
repository for all site and Sponsor regulatory documents. These records include the 
following: 
• Correspondence with the Sponsor or designee, the Medical Monitor, and other 
investigators 
• Subject source records, including but not limited to: Informed Consent Forms, 
copies of all completed eCRFs, and supporting documents (laboratory reports and 
reports of diagnostic tests, medical records, etc.) 
• All versions of the study protocol  
• Documentation of protocol deviations  
• Reports of any serious adverse event and serious adverse device effects, if any 
• A copy of all approvals related to the clinical study 
• The approved, blank, informed consent form  
• All approval/acknowledgment letters from the IRB/EC for all versions of the 
study protocol, ICF and other documents 
• Clinical Trial Agreement(s) 
• Signed and dated curriculum vitae for all study personnel  
• Medical licenses or equivalent for the Principal Investigator and all participating 
sub-Investigators 
• Financial disclosure for the Principal Investigator and all participating sub-
Investigators  
• All required regulatory documents such as Delegation of Authority and training 
logs 
• Signed Protocol Signature Page(s)  
• Data Privacy Agreements for the Principal Investigator and all hospital staff 
directly involved in the study (EU sites only) 
• Product liability certificates (EU sites only) 
8 
Sponsor Responsibilities 
 Training 
The Sponsor is responsible for providing training on the protocol, study device, eCRF 
completion, image upload as applicable for all study staff per delegation of authority log.  
 Investigator List 
The Sponsor shall keep a list of the names and addresses of the clinical investigators for 
the study, including the investigator role and his specialty. 
 

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 Adverse Event Reporting 
The Sponsor shall evaluate adverse event reports received from the study sites and found 
during data monitoring and shall report them to the appropriate regulatory bodies and 
other study sites as necessary. 
 Data Monitoring 
Penumbra is responsible for ensuring that the study is conducted according to applicable 
portions of the regulations (US Food and Drug Administration 21 CFR 812, ISO 14155). 
A Penumbra employee or designate will conduct the following site visits: 
8.4.1 Site Qualification Visit 
Conducted to ensure the study site has the appropriate staff, facilities, and expertise 
to participate in the study. Site Qualification can be waived under certain 
circumstances. 
8.4.2 Site Initiation Visit 
Conducted to train the study staff on use of the device, study requirements, and 
other relevant training. 
8.4.3 Interim Monitoring Visit 
Conducted as needed to ensure the study site is operating in compliance with this 
protocol, continues to have the appropriate staff and facilities, and is correctly 
completing the eCRFs.  
To ensure that Investigators and their staff understand and accept their defined 
responsibilities, the Sponsor will maintain regular correspondence and perform 
periodic site visits during the course of the study to verify the continued acceptability 
of the facilities, compliance with the protocol, and maintenance of complete records. 
Clinical monitoring will include review and resolution of missing or inconsistent 
data and source document checks to ensure the accuracy of the reported data. 
Informed consent, eCRFs and medical records for all enrolled and screen failed 
subjects will be made available to the Sponsor for review and collection.  
8.4.4 Site Close Out Visit  
Conducted to ensure all study and regulatory-related activities have been completed 
prior to site closure. 
 Data Management 
eCRFs will be used at all study sites. All study data will be entered into commercially 
available web-based EDC. Data entry will be performed by the study site personnel. 
Investigators are responsible for completion and timely submission of the data to the 
Sponsor. Every reasonable effort should be made to complete data entry within 7 days of 
data collection. This EDC system requires no on-site software installation or specific 

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hardware to operate. Investigators, clinical coordinators, data managers, and Penumbra 
clinical personnel access project information and study data centrally via a web browser.  
Automated data quality checks will display warnings for invalid data. Additionally, 
manual review of data listings may be used to identify data discrepancies or 
inconsistencies. The study site may be queried for clarification concerning eCRF 
discrepancies or inconsistencies identified. If eCRF corrections are necessary, they will 
be made by the Investigator or an authorized member of the Investigator's staff that is 
delegated to eCRF/EDC. Questions or problems with submitted data will be addressed 
with the Principal Investigator via an electronic querying system, or through direct 
contact. The Investigator will review the eCRFs for completeness and accuracy and 
provide his/her electronic signature and date to eCRFs as evidence thereof. Any data items 
that have been changed will require reapplication of the electronic signature. 
Study personnel will have individual login and password to access the clinical study 
information based upon each individual’s roles and responsibilities. The application 
provides hierarchical user permission data entry, viewing, and reporting options. 
All data entry and data update information, including the date and person performing the 
action, will be available via the audit trail, which is part of the EDC system. 
All eCRFs and data files will be secured to ensure confidentiality. Investigators are 
required to maintain source documents required by the protocol, including laboratory 
results, reports, supporting medical records, and Informed Consent Forms. The source 
documents will be used during the regular monitoring visits to verify information entered 
on the eCRFs. 
9 
Ethical Requirements 
 Declaration of Helsinki 
The study will be performed in accordance with the applicable aspects of ISO 14155, 
recommendations guiding physicians in biomedical research involving human subjects 
adopted by the 18th World Medical Assembly, Helsinki, Finland (1964 and later 
revisions), ICH and US FDA GCP guidelines. 
It is the responsibility of the Investigator to obtain approval of the study protocol from the 
IRB/EC and to keep the IRB/EC informed of any serious adverse event, serious adverse 
device effects, and amendments to the protocol. All correspondence with the IRB/EC 
should be filed by the Investigator and copies sent to the Sponsor or its designee. 
 Informed Consent 
The Investigator is responsible for ensuring that a completed informed consent is obtained 
in accordance with Section 6.5 of this protocol, as delegated by the site-specific 
Delegation of Authority, and according to country and local requirements. 
 

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 Subject Data Protection 
Each subject will be assigned a unique subject identification number at the time of 
enrollment. This subject identification number will be retained throughout the study. 
Study sites will keep a log that notes the subject’s name and corresponding subject 
identification number. All eCRFs will be tracked, evaluated, and stored using only the 
subject ID number. No personal identifying information will be included on the eCRFs. 
The informed consent form will notify subjects that study monitors, Sponsor’s 
representatives, auditors, and representatives of government agencies and ethics 
committees will have access to personal identifying information to ensure that data 
reported on the eCRFs corresponds to the person who signed the consent form and the 
information contained in the source documentation. 
Each subject must be informed that the data collected will be stored and analyzed by 
computer and the applicable national regulations for handling of computerized data will 
be followed. Furthermore, each subject should be informed about the possibility of 
inspection of relevant parts of the hospital records by the Sponsor, or other Health 
Authorities, including the FDA; and that the data will be electronically stored in the United 
States. 
10 Statistical Procedures 
 General Statistical Considerations 
All confidence intervals presented will be two-sided. All statistical tests will be two-tailed 
with a significance level of 0.05. Descriptive statistics will be provided. This includes the 
number of observations, mean, median, standard deviation, inter-quartile range, minimum 
and maximum for continuous variables and counts and percentages for discrete variables. 
Analyses will be conducted using SAS (SAS Institute, Cary, NC). The specific details of 
the planned analyses are described completely in the statistical analysis plan. 
 Sample Size Estimation for the Primary Outcome 
The sample size calculations assume that 94% (108/115) of the study subjects achieve 
target limb salvage 1-month post-procedure as compared to 95.7% patients undergoing 
current standard of care treatments. Based on a binomial analysis with a non-inferiority 
margin of 10%, a study of 115 enrolled subjects will have 80% power with a one-sided 
alpha of 0.025. The sample size was adjusted to 130 subjects to account for approximately 
10% attrition. 
 Control of Systematic Error and Bias 
The study will be conducted under a common protocol for each study site with the intention 
of pooling the data for analysis. Every effort will be made to promote consistency in study 
execution at each study site.  
 Missing Data and Imputation Methods 
Every effort will be made to keep all missing data, particularly at the 30-day follow-up 
visit, to a minimum. Some data may be missing, mainly due to lost-to-follow-up (LTFU) 

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subjects. The primary analysis will be data as observed. Sensitivity analysis will be 
performed. 
 Definition of Populations 
10.5.1 Screened 
Screened subjects are all subjects considered for participation in the study, whether 
or not they sign informed consent. 
10.5.2 Screen Failure 
Screen failure subjects are all subjects considered for participation in the study, who 
failed to meet inclusion criteria or met exclusion criteria. Patients can be screen 
failed based on general criteria. These patients may or may not have signed an 
informed consent form. 
10.5.3 Enrolled  
An eligible patient is considered enrolled once informed consent is obtained and 
Indigo Aspiration System has been inserted into the body.  
10.5.4 Completed 
Completed subjects are all subjects who were enrolled and completed the study 
follow-up or were known to have died prior to the follow-up timepoint are 
considered completed. The completed subject metric will be provided for 365-day 
follow-up. 
10.5.5 Early Termination  
Early termination subjects are all subjects who were enrolled but did not complete 
follow-up and were not known to have died are considered early termination 
subjects. The early termination subject metric will be provided for 365-day follow-
up. 
 Definition of Analysis Populations 
10.6.1  Intent to Treat Sample 
As the primary analysis, all performance and safety outcome measures will be 
analyzed under the intent-to-treat (ITT) principle. Under this principle, the ITT 
sample includes all subjects who are enrolled. This population is the primary 
analysis population.   
 Interim Analysis 
No interim analyses are planned for the purpose of terminating the study for a positive 
result. Interim analysis without hypothesis testing may be performed for regulatory 
submission or publication of study results. No adjustments will be made to the confidence 
bounds for the final analysis.  

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 Statistical Analysis of Primary Endpoint  
The primary endpoint is the target limb salvage rate at 1-month post-procedure. The 
primary safety analysis will be the difference between the study group and the combined 
historical control rate of 95.7% observed under current standards of care. 
The null hypothesis is that the difference between the primary endpoint rate and the 
standard of care at 1-month post-procedure is less than or equal to -10%. The alternative 
hypothesis is the difference at 1-month post-procedure is greater than -10%. Formally, the 
null and alternative hypotheses to be tested are as follows: 
H0:  Pstudy – 0.957 ≤ - 0.10 
HA:  Pstudy – 0.957 > - 0.10 
Where Pstudy is the proportion of patients who achieve target limb salvage 1-month post-
procedure. 
The primary safety endpoint is met if the lower limit of the 95% confidence interval of the 
primary endpoint rate is greater than 85.7%. The primary safety analysis will be 
unadjusted.   
 Secondary Statistical Analysis 
The secondary performance and safety endpoints will be assessed via proportions based on 
the endpoint criteria and 95% confidence intervals will be presented. The modified SVS 
runoff score will be analyzed both as a categorical and a continuous outcome. Survival 
estimates will also be utilized to evaluate the time-to-event using Kaplan-Meier 
methodology for events through 365 days. With the date of procedure set at day 0, any 
event occurring on or before day 365 will be included.  
 Analysis of Adverse Events 
All adverse events will be summarized by showing the number and percent of subjects 
which report the event.  Events will also be reported by relationship to the procedure or 
device. Adverse events judged as probably or definitely related to the Indigo Aspiration 
System will be analyzed as device-related.   
 Baseline Characteristics 
Baseline data including, but not limited to demographics, clinical characteristics, and 
angiographic characteristics will be summarized using descriptive statistics.  
 Pooling Across Centers 
Analyses will be presented by treatment group using data pooled across sites. Adjusted 
analysis using key baseline variables and the study site will be used to assess any potential 
site effects. This analysis will be performed on the intent-to-treat population.   
 
 

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 Final Report  
A final report will be completed, even if the study is prematurely terminated. At the 
conclusion of the study, a multi-center abstract reporting the results will be prepared and 
may be presented at a major meeting(s). A multi-center publication may also be prepared 
for publication in a reputable scientific journal. The publication of results from any single 
center experience within the study is not allowed until the aggregate study results have 
been published, unless there is written consent from the Sponsor. 
11 Study Committees and Core Labs  
 
Imaging Core Lab 
The Imaging Core Lab is composed of independent medical doctor(s) who are not 
participants in the study. The Imaging Core Lab is responsible for assisting in the 
development of specific criteria used for the categorization of clinical endpoints in the 
study. A web-based electronic database will be provided for the Imaging Core Lab to 
review and adjudicate images. Additional details related to the core lab are specified in the 
Imaging Core Lab Charter 
The independent imaging core lab will review images from the pre-procedure and post-
procedure (pseudonymized) angiograms to determine at minimum, the TIMI scores. An 
Imaging core lab charter will provide procedures for core lab review.  
12 Study Administration 
 
Stopping the Study Based on Interim Safety Data   
The Medical Monitor will review periodic safety reports of all AEs and SAEs. The study 
can be temporarily suspended to evaluate any negative safety trends.  
 
Clinical Study Termination/Withdrawal 
Subjects may be terminated or withdrawn from the study for the following reasons: 
• Voluntary withdrawal of consent–– meaning that a subject voluntarily chooses 
not to participate further in the study.  All data collected up to the withdrawal of 
consent will be maintained in the study database. Withdrawn subjects will not 
have any additional follow-up and will not be replaced. 
• Lost to follow-up –– a subject will be considered lost-to-follow-up when contact 
is not achieved at the last required follow-up visit window.  At a minimum, the 
effort to obtain follow-up information will include three (3) attempts to make 
contact via telephone or e-mail and if unsuccessful, then a letter from the 
Investigator sent via courier or other traceable method will be sent to the subject’s 
last known address. These efforts to obtain follow-up will be recorded in the 
subject’s study files. 
• Subjects may also be withdrawn at the Investigator’s discretion if within their 
best interest. A subject’s participation in the clinical study will be terminated if 
the Investigator believes that this is in the subject’s best medical interest or if the 
subject no longer complies with the clinical study requirements. 

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The sponsor may temporarily suspend or prematurely terminate the study at any time for 
the following reasons: 
• Suspicion of risk to subjects 
• If no positive IRB/EC decision is obtained or if the judgement of the IRB/EC is 
revoked 
• If the applicable regulatory body has made an irrevocable objection 
• If it transpires that continuation of study cannot serve any scientific purpose, and 
this is confirmed by the IRB/EC 
• Business reasons  
The Sponsor will document reasons for study suspension or premature termination and 
notify the PIs. The Sponsor will ensure that the IRB/ECs and regulatory authorities are 
notified in a timely manner.  
The Sponsor will continue to provide resources to fulfil the obligations from the study 
protocol and existing agreements for following up the subjects enrolled in the study. 
The Principal Investigators will promptly inform the enrolled subjects at his/her site, 
if appropriate. 
If the Sponsor temporarily suspends the study and wishes to resume it, the Sponsor will 
inform the PIs, IRB/ECs, and (if appropriate) regulatory authorities.  The Sponsor will 
provide a rationale for resuming the study.  IRB/ECs must provide written approval 
before the study is resumed. 
 
Missing Visits 
Every effort should be made to bring subject in to scheduled follow-up visits. Any study 
subject who does not attend a scheduled follow-up visit should be contacted by site 
personnel to reschedule. If the missed visit was due to an adverse event, an AE eCRF must 
be completed and any reporting requirements met.  
 
Protocol Adherence and Amendments 
Prior to beginning the study, the Principal Investigator must sign the protocol signature 
page documenting his/her agreement to conduct the study in accordance with this protocol. 
Deviations outlined in section 7.6.4 must be documented and reported to Penumbra as soon 
as possible, and to the IRB/EC per local guidelines and government regulations. 
 
Study Registration 
The study will be registered in a publicly accessible trial study database (e.g., clinical 
trials.gov) prior to study initiation. 
13 Publication of Information 
All information and data generated in association with this study will be held in strict 
confidence and remain the sole property of the Sponsor. The Investigator agrees to use this 

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information for the sole purpose of completing this study and for no other purpose without 
written consent from the Sponsor. 
The results of this study may be offered for publication. The Investigators and the Sponsor 
shall collaborate in the writing of the study to ensure accuracy.  All information not previously 
published concerning the test device and research, including patent applications, 
manufacturing processes, basic scientific data, etc., is considered confidential and should 
remain the sole property of Penumbra.  The Investigator agrees to use this information only 
in connection with this study and will not use it for other purposes without written permission 
from the Sponsor. 
 
 

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15  References 
1. 
Gilliland, C., Shah, J., Martin, J.G., and Miller, M.J., Jr. (2017). Acute limb ischemia. 
Tech Vasc Interv Radiol. 20(4): p. 274-280. 
2. 
Gerhard-Herman, M.D., Gornik, H.L., Barrett, C., Barshes, N.R., Corriere, M.A., 
Drachman, D.E., . . . Walsh, M.E. (2017). 2016 aha/acc guideline on the management of 
patients with lower extremity peripheral artery disease: A report of the american college 
of cardiology/american heart association task force on clinical practice guidelines. J Am 
Coll Cardiol. 69(11): p. e71-e126. 
3. 
Aboyans, V., Ricco, J.B., Bartelink, M.E.L., Bjorck, M., Brodmann, M., Cohnert, T., . . . 
Zamorano, J.L. (2018). Editor's choice - 2017 esc guidelines on the diagnosis and 
treatment of peripheral arterial diseases, in collaboration with the european society for 
vascular surgery (esvs). Eur J Vasc Endovasc Surg. 55(3): p. 305-368. 
4. 
Howard, D.P., Banerjee, A., Fairhead, J.F., Hands, L., Silver, L.E., and Rothwell, P.M. 
(2015). Population-based study of incidence, risk factors, outcome, and prognosis of 
ischemic peripheral arterial events: Implications for prevention. Circulation. 132(19): p. 
1805-15. 
5. 
Baril, D.T., Ghosh, K., and Rosen, A.B. (2014). Trends in the incidence, treatment, and 
outcomes of acute lower extremity ischemia in the united states medicare population. J 
Vasc Surg. 60(3): p. 669-77 e2. 
6. 
Acar, R.D., Sahin, M., and Kirma, C. (2013). One of the most urgent vascular 
circumstances: Acute limb ischemia. SAGE Open Med. 1: p. 2050312113516110. 
7. 
Creager, M.A., Kaufman, J.A., and Conte, M.S. (2012). Clinical practice. Acute limb 
ischemia. N Engl J Med. 366(23): p. 2198-206. 
8. 
Rutherford, R.B., Baker, J.D., Ernst, C., Johnston, K.W., Porter, J.M., Ahn, S., and Jones, 
D.N. (1997). Recommended standards for reports dealing with lower extremity ischemia: 
Revised version. J Vasc Surg. 26(3): p. 517-38. 
9. 
Leung, D.A., Blitz, L.R., Nelson, T., Amin, A., Soukas, P.A., Nanjundappa, A., . . . 
Simoni, E.J. (2015). Rheolytic pharmacomechanical thrombectomy for the management 
of acute limb ischemia: Results from the pearl registry. J Endovasc Ther. 22(4): p. 546-
57. 
10. 
Investigators, T.S. (1994). Results of a prospective randomized trial evaluating surgery 
versus thrombolysis for ischemia of the lower extremity. The stile trial. Ann Surg. 220(3): 
p. 251-66; discussion 266-8. 
11. 
Ouriel, K., Shortell, C.K., DeWeese, J.A., Green, R.M., Francis, C.W., Azodo, M.V., . . . 
Marder, V.J. (1994). A comparison of thrombolytic therapy with operative 
revascularization in the initial treatment of acute peripheral arterial ischemia. J Vasc 
Surg. 19(6): p. 1021-30. 
12. 
Ouriel, K., Veith, F.J., and Sasahara, A.A. (1996). Thrombolysis or peripheral arterial 
surgery: Phase i results. Topas investigators. J Vasc Surg. 23(1): p. 64-73; discussion 74-
5. 
13. 
Morrison, H.L. (2006). Catheter-directed thrombolysis for acute limb ischemia. Semin 
Intervent Radiol. 23(3): p. 258-69. 
14. 
Shishehbor, M.H. (2014). Acute and critical limb ischemia: When time is limb. Cleve 
Clin J Med. 81(4): p. 209-16. 

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15. 
Kwok, C.H.R., Fleming, S., Chan, K.K.C., Tibballs, J., Samuelson, S., Ferguson, J., . . . 
Jansen, S.J. (2018). Aspiration thrombectomy versus conventional catheter-directed 
thrombolysis as first-line treatment for noniatrogenic acute lower limb ischemia. J Vasc 
Interv Radiol. 29(5): p. 607-613. 
16. 
Saxon, R.R., Benenati, J.F., Teigen, C., Adams, G.L., Sewall, L.E., and Trialists, P. 
(2018). Utility of a power aspiration-based extraction technique as an initial and 
secondary approach in the treatment of peripheral arterial thromboembolism: Results of 
the multicenter prism trial. J Vasc Interv Radiol. 29(1): p. 92-100. 
17. 
Duval, S., Keo, H.H., Oldenburg, N.C., Baumgartner, I., Jaff, M.R., Peacock, J.M., . . . 
Hirsch, A.T. (2014). The impact of prolonged lower limb ischemia on amputation, 
mortality, and functional status: The friends registry. Am Heart J. 168(4): p. 577-87. 
18. 
Hardman, R.L., Jazaeri, O., Yi, J., Smith, M., and Gupta, R. (2014). Overview of 
classification systems in peripheral artery disease. Semin Intervent Radiol. 31(4): p. 378-
88. 
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Surgery, T.W.G.a.t.S.f.V. (2000). Clinical classification of acute limb ischemia. J of Vasc 
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20. 
Stoner, M.C., Calligaro, K.D., Chaer, R.A., Dietzek, A.M., Farber, A., Guzman, R.J., . . . 
Society for Vascular, S. (2016). Reporting standards of the society for vascular surgery 
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21. 
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Nordanstig, J., Wann-Hansson, C., Karlsson, J., Lundstrom, M., Pettersson, M., and 
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quality of life assessment in peripheral arterial disease. J Vasc Surg. 59(3): p. 700-7. 
 
 
 

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16 APPENDIX I: Definitions and Classifications 
 Definitions 
Acute Limb Ischemia: 
Acute (≤14 days), severe hypoperfusion of the limb 
characterized by these features: pain, pallor, pulselessness, 
poikilothermia (cold), paresthesias, and paralysis.2 
Amputation:  
The complete or partial removal of lower limb or extremity. 
Minor amputation is surgical removal of a portion or 
segment of the lower extremity distal or through the 
tarsometatarsal joints. 
Major amputation is complete or partial removal that occurs 
proximal to the tarsometatarsal joints.22  
Limb Salvage: 
Condition of extremity with potential to secure viability and 
preserve motor function to the weight-bearing portion of the 
foot if treated.2 
Limb is considered salvagable if amputation is performed  at 
or distal to tarsal/metatarsal joint.22 
Major Bleeding: 
Fatal or leading to a drop in hemoglobin of ≥5 g/dl, or 
significant hypotension with the need for inotropes, or 
requiring surgery (other than vascular site repair), or 
symptomatic intracranial hemorrhage (ICH), or requiring 
transfusion of two or three units of red blood cells or 
equivalent whole blood.   
Minor Bleeding: 
Bleeding that results in a drop in hemoglobin 3 to <5 g/dL 
and/or that requires a blood transfusion of 1 unit of red blood 
cells or equivalent whole blood. 
Modified SVS Runoff Score: 
Calculated using the angiogram by assessing the patency and 
degree of stenosis/occlusion in the popliteal artery and the 
three tibial vessels.17  
Nonviable Limb: 
Condition of extremity (or portion of extremity) in which 
loss of motor function, neurological function, and tissue 
integrity cannot be restored with treatment.2 
Patency: 
Patency is defined as a target lesion without a 
hemodynamically significant stenosis/reocclusion on duplex 
ultrasound (>50%,) and without target lesion reintervention 
(TLR). 
TransAtlantic Inter-Society 
Consensus for the Management of 
Peripheral Arterial Disease (TASC II) 
Score 
Used to classify vessel or arterial disease severity in the 
aortoiliac and femoropopliteal segments. 

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 Acronyms 
AAA 
Abdominal Aortic Aneurysm 
ABI 
Ankle-Brachial Index  
ADE 
Adverse Device Effect 
AE 
Adverse Event 
CDT 
Catheter-Directed Thrombolysis  
CFA 
Common Femoral Artery 
CFR 
Code of Federal Regulations 
CIA 
Common Iliac Artery 
DSMB 
Data and Safety Monitoring Board 
DUS 
Duplex Ultrasound 
eCRFs 
Electronic Case Report Forms 
EC 
Ethics Committee 
EDC 
Electronic Data Capture 
EIA 
External Iliac Artery 
FDA 
Food and Drug Administration 
GCP 
Good Clinical Practice 
ICF 
Informed Consent Form 
IFU 
Instructions for Use 
IRB 
Institution Review Board 
ISO 
International Standards Organization 
ITT 
Intent-To-Treat 
LAR 
Legally Authorized Representative 
LE ALI 
Lower Extremity Acute Limb Ischemia 
LTFU 
Lost to Follow-up 
PAT 
Percutaneous Aspiration Thrombectomy  
PMT 
Pharmacomechanical Thrombectomy  
RHV 
Rotating Hemostasis Valve  
SAE 
Serious Adverse Event 
SFA 
Superficial Femoral Artery 
SOC 
Standard of Care 
SVS 
Society for Vascular Surgery  
TASC II  
TransAtlantic Inter-Society Consensus for the Management of Peripheral 
Arterial Disease  
TMF 
Trial Master File 
TIMI 
Thrombolysis in Myocardial Infarction 
UADE 
Unanticipated Adverse Device Event  
US 
United States 
VascuQoL-6 
Vascular Quality of Life Questionnaire-6  
XTRACT 
Aspiration–Based Extraction Technique