Management of In-stent Restenosis after Lower Extremity Endovascular Procedures

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1 Management of In-stent Restenosis after Lower Extremity Endovascular Procedures Piotr Sobieszczyk, MD Associate Director, Cardiac Catheterization Laboratory Cardiovascular Division and Vascular Medicine Section Brigham and Women s Hospital Harvard Medical School Boston, USA

2 In-Stent Restenosis (ISR) Neointima formation: proliferation and migration of smooth muscle cells and extracellular matrix formation Binary definition: >50% narrowing of stent lumen Angiographic criteria: 50% reduction in luminal diameter Ultrasound criteria: Peak systolic velocity ratio >2.5 Within 1 hr Low incidence in iliac stents Incidence of 20% in recent SFA stent trials Incidence of ISR in tibial vessels not well defined 1-6 months Risk of ISR increases with stent length Negative remodeling Neointima formation Neointima formation Sobieszczyk P. Welt F Cardiology Special Edition 2003;9:9

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4 Is detecting and treating ISR Important? Binary definition of 50% is not useful clinically: 50% lesion is unlikely to be hemodynamically important ISR re-intervention (TLR) What is clinically relevant ISR: PSVR >3? PSVR>4? Decrease in ABI >0.15? Recurrent symptoms? Threatened vessel patency? Is it important to the patient to keep the vessel patent?

5 Ittis much easier to treat stent restenosis than stent occlusion.

6 Is clinically relevant ISR worth treating? Can we accurately diagnose it? Surveillance Duplex US Symptoms Clinical Exam, ABI Does treating ISR improve clinical outcomes? does it improve long term patency? does it prevent limb loss? does it protect functional capacity? Is there effective therapy for ISR?

7 Does surveillance and treatment of ISR impact long term procedure durability? Surveillance and re-intervention may impact durability in long (>200 mm) and intermediate length mm) stents, but not in shorter lesions. Outpatient surveillance and target re-intervention can achieve 2.5 year patency rates of 76% in stents >200mm Connors G, Todoran, Sobieszczyk P, Catheterization and Cardiovascular Interventions 2011

8 Treatment Options for ISR There is no consensus regarding optimal management of ISR There are no randomized trials comparing various endovascular therapies for ISR Possible interventions used to treat ISR: PTA Restenting: covered vs. standard self-expanding stents Drug eluting stents Drug eluting balloons Atherectomy: DiamondBack, SilverHawk, Pathway, Rotarex catheters Vascular brachytherapy for established ISR

9 Treatment of ISR: PTA and atherectomy Balloon angioplasty alone Can be effective if focal ISR Fails in diffuse ISR pattern Atherectomy Debulking of plaque followed by PTA Variable results: 32 limbs treated between Primary patency rate 58% at 12 months TLR rate 53% at 12 months Silingardi R, J. Cardiovasc Surg 2010;51:543

10 Drug Eluting Balloons for ISR Short-term Results 12 month Freedom from Target Lesion Revascularization (TLR) Mean lesion length 80 mm 95% CI 92% 95% CI Stabile E, et al. J Am Coll Cardiol 2012;60:1739

11 Restenting of ISR Standard nitinol self-expanding stents resetting the clock of neo intimal proliferation? Covered PTFE Viabahn stents Possibly increased risk of thrombosis 63% primary patency in 27 limbs with mean ISR length 214mm. Gorgani F, J. Invasive Cardiol 2013;25:670 48% primary patency rate in 27 pts with mean ISR length 207 mm Laird J, Catheter Cardiovasc Interventions 2012;80:852 Drug eluting stents

12 Drug Eluting Stent for ISR: ZILVER PTX 108 patients, 119 limbs Mean restenotic lesion length 133 mm 79% 81% 61% Primary Patency ( No restenosis on US: PSVR<2.5) Freedom from TLR Reintervention for >50% angiographic stenosis Zeller T, J. Amer Coll Cardiol: Intervention 2013;6:274

13 Vascular Brachytherapy for SFA ISR: The BWH Experience PTA combined with endovascular radiation therapy (brachytherapy) Iridium-192 isotopes were used to deliver a single fraction of 20 Gy at a prescription point of between millimeters. 42 limbs treated between 12/2003 and 2/2010 Indications for re-intervention: Recurrent symptoms 95% CLI 2.5% Asymptomatic high-grade ISR on US: 2.5% Mode of index stent failure Restenosis 74% Occlusion 21% Thrombosis 2.5% Mean lesion length 262 mm(40-480mm)

14 Superficial Femoral Artery Brachytherapy

15 Distal SFA/Popliteal Brachytherapy Index Intervention 1 year follow up PTA/brachytherapy 6 years later

16 Freedom from TVR Vascular Brachytherapy for ISR: The BWH Experience Months Levy M, Sobieszczyk P, Catheterization Cardiovascular Interventions 2010;75:S93

17 In Stent Restenosis: Unanswered Questions It makes clinical sense to look for it and treat it but there are no trials to prove it Is a surveillance protocol appropriate for every SFA stent? How long doe we need to worry about ISR Which therapy (if any) is most effective for ISR

18 Brigham and Women s Hospital BWH Cardiovascular Center

19 Patency of infra-inguinal vein grafts-effect of intraoperative Doppler assessment and a graft surveillance program N=254 grafts were entered into a graft surveillance program Primary patency: 81% at 6 weeks 42% at 3 years Primary-assisted patency: 83% at 6 weeks 64% at 3 years J Vasc Surg Jun;49(6):