Secondary Intervention in Secondary Intervention in Unfavorable AAA Neck AnatomyUnfavorable AAA Neck Anatomy

Congress Symposium 2007Congress Symposium 2007John T. Collins, MDJohn T. Collins, MD

Borgess Medical CenterBorgess Medical CenterKalamazoo, MIKalamazoo, MI

PowerlinkPowerlink®® System: System:

Unibody-Bifurcated Design Unibody-Bifurcated Design Long Main BodyLong Main Body Low-Porosity Proprietary Low-Porosity Proprietary

ePTFE FormulationePTFE Formulation Cobalt Chromium Alloy StentCobalt Chromium Alloy Stent Single-wire Main Body Single-wire Main Body

ConstructionConstruction Fully SupportedFully Supported

Minimally Invasive AccessMinimally Invasive Access

21 Fr Delivery System - Ipsilateral21 Fr Delivery System - Ipsilateral No introducer sheath usedNo introducer sheath used No upsizing of arteriotomy required No upsizing of arteriotomy required

9 Fr Percutaneous Sheath - Contralateral9 Fr Percutaneous Sheath - Contralateral

PowerlinkPowerlink®® U.S. Pivotal Trial U.S. Pivotal Trial 192 patients enrolled between July 2000 and March 2003192 patients enrolled between July 2000 and March 2003

Eligibility CriteriaEligibility Criteria Proximal Infrarenal Neck:Proximal Infrarenal Neck:

• >>15mm length15mm length• <60<60° angle° angle• 26mm maximum diameter, 18mm minimum diameter26mm maximum diameter, 18mm minimum diameter

AAA AAA >>4.0 cm diameter or rapidly growing AAA4.0 cm diameter or rapidly growing AAA Iliac diameter Iliac diameter >>7mm on at least one side (for access)7mm on at least one side (for access) Dispensable inferior mesenteric arteryDispensable inferior mesenteric artery Preservation of at least one hypogastric arteryPreservation of at least one hypogastric artery Iliac seal zone of Iliac seal zone of >>15mm length (15mm length (<<18mm diameter)18mm diameter) Aortic bifurcation diameter Aortic bifurcation diameter >>18mm18mm >>18 years old18 years old Not pregnantNot pregnant Candidate for open AAA repairCandidate for open AAA repair Serum creatinine Serum creatinine <<1.7mg/dlL1.7mg/dlL Willingness to comply with follow-up scheduleWillingness to comply with follow-up schedule No bleeding disordersNo bleeding disorders Life expectancy >2 yearsLife expectancy >2 years No connective tissue disordersNo connective tissue disorders

Summary of Significant Early Clinical FindingsSummary of Significant Early Clinical FindingsPowerlinkPowerlink ControlControl P-valueP-value

AgeAge 73.2 73.2 ++ 7.0 7.0 69.7 69.7 ++ 7.9 7.9 <0.0008<0.0008 Successful DeploymentSuccessful Deployment 188/192 – 97.9%188/192 – 97.9% N/AN/A N/AN/A Patients with at least 1 Patients with at least 1 MajorMajor†† AE (0-30days) AE (0-30days) 13/192 - 6.8%13/192 - 6.8% 14/66 - 21.2%14/66 - 21.2% <0.0020<0.0020

All Death All Death << 30 days 30 days 2*/192 - 1.0%2*/192 - 1.0% 4/66 - 6.1%4/66 - 6.1% < 0.0389< 0.0389 Anesthesia Time (min)Anesthesia Time (min) 185.1 185.1 ++ 82.2 82.2 293.8 293.8 ++ 111.5 111.5 <0.0001<0.0001 Procedure Time (min)Procedure Time (min) 135.9 135.9 ++ 65.9 65.9 222.3 222.3 ++ 100.1 100.1 <0.0001<0.0001 Blood Loss (l)Blood Loss (l) 0.34 0.34 ++ 0.41 0.41 1.58 1.58 ++ 1.6 1.6 <0.0001<0.0001 Days in ICUDays in ICU 0.78 0.78 ++ 1.5 1.5 4.1 4.1 ++ 8.4 8.4 <0.0001<0.0001 Days to DischargeDays to Discharge 3.3 3.3 ++ 3.4 3.4 9.5 9.5 ++ 7.7 7.7 <0.0001<0.0001

† † Defined as death, MI, stroke, AAA rupture, conversion, secondary procedure, Defined as death, MI, stroke, AAA rupture, conversion, secondary procedure, coronary intervention, renal failure, or respiratory failurecoronary intervention, renal failure, or respiratory failure

* Not device related

Carpenter JP, et al. Midterm results of the multicenter trial of the Powerlink bifurcated system for endovascular aortic aneurysm repair. J Vasc Surg 2004;40:849-59.

Freedom from AAA Mortality

0

20

40

60

80

100

0 1 3 6 12 18 24 36 48 60

Months Post-Implant

% S

urvi

val

PowerlinkControl

Secondary Procedures Secondary Procedures (through 60 months*)(through 60 months*)

34 procedures in 26 patients34 procedures in 26 patients Endoleak –23 (Cuffs, embolization, balloon Endoleak –23 (Cuffs, embolization, balloon

dilatation)dilatation)• Type I Endoleak – 5Type I Endoleak – 5• Type II Endoleak –18Type II Endoleak –18

Graft Limb Occlusion – 7 Graft Limb Occlusion – 7 • Embolectomy,Stent, PTA, or Lytic TherapyEmbolectomy,Stent, PTA, or Lytic Therapy

Native Artery Procedures – 3Native Artery Procedures – 3 Migration - 1Migration - 1

* As of Dec. 2006

Sac Diameter Over TimeSac Diameter Over Time††

† As of Dec. 2006

* 192 patients enrolled, 3 patients’ CT’s lost before submission to core lab

Diameter Diameter (mm)(mm)

Pre-opPre-op(N=189)(N=189)**

12 mo12 mo(N=147(N=147

))

24 mo24 mo(N=142(N=142

))

36 mo36 mo(N=130(N=130

))

48 mo48 mo(N=114)(N=114)

60 mo60 mo(N=54)(N=54)

Mean Mean (SD)(SD)

50.4050.40(6.98)(6.98)

45.7745.77(7.94)(7.94)

43.1343.13(9.01)(9.01)

41.4941.49(9.35)(9.35)

40.7040.70(9.78)(9.78)

38.1638.16(8.71)(8.71)

MinimumMinimum 37.3037.30 30.2030.20 27.0027.00 26.8026.80 27.1027.10 27.3027.30MaximumMaximum 74.3074.30 72.4072.40 69.7069.70 72.1072.10 73.5073.50 68.4068.40

Sac Volume Over TimeSac Volume Over Time††

† As of Dec 2006

* 192 patients enrolled, 3 patients’ CT’s lost before submission to core lab

** Some CT scans are not evaluable for some parameters most often due to poor image quality, no contrast, CT’s taken at greater than 3mm slices, etc.

Volume (cc)Volume (cc) Pre-opPre-op(N=187)*(N=187)*

12 mo12 mo(N=144)(N=144)

24 mo24 mo(N=139)(N=139)

36 mo36 mo(N=129)(N=129)

48 mo48 mo(N=114)(N=114)

60 mo60 mo(N=54) (N=54)

Mean Mean (SD)(SD)

135.4135.4(39.4)(39.4)

124.6124.6(40.3)(40.3)

119.1119.1(38.4)(38.4)

115.3115.3(37.2)(37.2)

113.6113.6(37.9)(37.9)

110.6110.6(37.2)(37.2)

MinimumMinimum 70.870.8 62.862.8 58.358.3 54.154.1 59.359.3 69.569.5MaximumMaximum 270.5270.5 292.4292.4 293.9293.9 279.2279.2 262.4262.4 277.9277.9

UnevaluableUnevaluable**** 22 33 33 11 00 00

Large diameter (>28mm)Large diameter (>28mm) Short landing zone (<15mm)Short landing zone (<15mm) Extreme AngulationExtreme Angulation Accessory renal arteriesAccessory renal arteries Reverse tapered neckReverse tapered neck

Challenging Infrarenal Aortic Neck Challenging Infrarenal Aortic Neck AnatomyAnatomy

ObjectiveObjective

Evaluate the incidence of Type I Evaluate the incidence of Type I endoleaks and device migration in patients endoleaks and device migration in patients with reverse tapered neck anatomywith reverse tapered neck anatomy

Determine effect on seal zoneDetermine effect on seal zone Incidence of secondary interventions in Incidence of secondary interventions in

patients with this neck geometrypatients with this neck geometry

Reverse Tapered NeckReverse Tapered Neck

DefinitionDefinition

Neck Dilation of Neck Dilation of 2mm within the first 2mm within the first 20mm below the most caudal renal artery20mm below the most caudal renal artery

Reverse Tapered NeckReverse Tapered Neck

Reverse Tapered NeckReverse Tapered Neck

Sub-group AnalysisSub-group Analysis

N = 50 test patients (Total group = 192) N = 50 test patients (Total group = 192) had reverse tapered neck anatomyhad reverse tapered neck anatomy

Neck anatomyNeck anatomy Mean Proximal DiameterMean Proximal Diameter

• 20.94 mm (17.9--26.0)20.94 mm (17.9--26.0) Mean Distal Diameter Mean Distal Diameter

• 24.38 mm (21.5 – 28.6)24.38 mm (21.5 – 28.6)

Implant ProcedureImplant Procedure

All procedures technically successfulAll procedures technically successful 24 patients (24/50 = 48%) received 24 patients (24/50 = 48%) received

proximal extensions during procedureproximal extensions during procedure Diameter of stent graftsDiameter of stent grafts

25 or 28mm25 or 28mm 6 patients also received stents during 6 patients also received stents during

implant procedureimplant procedure No endoleaks noted at end of procedureNo endoleaks noted at end of procedure

Follow-up of Sub-GroupFollow-up of Sub-Group

Mean follow-up: 40.2 months Mean follow-up: 40.2 months Range: 1 mo – 64 moRange: 1 mo – 64 mo

No AAA-related deathsNo AAA-related deaths No secondary procedures for proximal No secondary procedures for proximal

Type I endoleakType I endoleak Graft migration: 1 (12.5mm); no clinical Graft migration: 1 (12.5mm); no clinical

sequelaesequelae

Courtesy of Rodney White, MD

Courtesy of Rodney White, MD

Courtesy of Rodney White, MD

Differences in CT Assessment

•Graft attached to endoskeleton only @ proximal and distal end

•Graft “balloons” off stent cage

•May allow graft to provide longer seal zone in unfavorable proximal neck geometry

Reverse Tapered NeckReverse Tapered Neck

Summary of Late Clinical FindingsSummary of Late Clinical Findings

97.9 % Freedom from AAA-Related Mortality 97.9 % Freedom from AAA-Related Mortality @ 5 years with the Powerlink System@ 5 years with the Powerlink System

No aneurysm rupturesNo aneurysm ruptures Only 1 late conversion (@ 1 yr.)Only 1 late conversion (@ 1 yr.) No ePTFE graft material failures @ 5 yearsNo ePTFE graft material failures @ 5 years No cobalt chromium stent graft failure or No cobalt chromium stent graft failure or

fatigue @ 5 yearsfatigue @ 5 years

ConclusionsConclusions

Simple implantation techniqueSimple implantation technique Minimally invasive accessMinimally invasive access No proximal Type I endoleak in this No proximal Type I endoleak in this

group of patients with reverse taper group of patients with reverse taper neck anatomy through 5 year follow-upneck anatomy through 5 year follow-up

Sac regression and improving Sac regression and improving morphologymorphology