Specificities for infrapopliteal stents Nicolas Diehm, M.D. Swiss Cardiovascular Center Clinical and Interventional Angiology University Hospital Bern, Switzerland
Disclosures Speaker`s Bureau: MEDRAD, Biotronik, Bristol-Myers Squibb, EV3, Cook Medical. Consulting: MEDRAD. Research Grants: Medtronic, Biotronik, Swiss National Foundation, Swiss Heart Foundation.
Truths in BTK Therapy Evidence Level A "In patients presenting with severe limb ischaemia due to infrainguinal disease and who are suitable for surgery and angioplasty, a bypass-surgery-first and a balloon-angioplasty-first strategy are associated with broadly similar outcomes in terms of amputationfree survival!.." Basil trial participants, Lancet 2005; 366: 1925 1934 "There is increasing evidence to support a recommendation for angioplasty in patients with CLI and infrapopliteal artery occlusion where inline flow to the foot can be re-established and where there is medical co-morbidity." Endovascular first in CLI!
Restenosis after POBA / Stenting of BTK Arteries! Meta-analysis of 30 studies published 1990 2006! n = 2653 limbs treated Romiti et al. J Vasc Surg 2008;47:975-81
Endovascular BTK Therapy Angiographic Restenosis
Different Stent Requirements
Commercially available BMS No results from randomized controlled trials. Study with small sample sizes. Patency data largely based on duplex ultrasound.
INPERIA Study! 95 lesions in 51 CLI patients.! Mean lesion length: 24 mm.! Randomized POBA (53 lesions) versus Carbostent (balloon-expandable; 42 lesions).! Follow-up: DSA or CTA at 6 months! Primary patency: 83.7% (Stent) versus 61.1% (POBA), p=0.02.! Limb salvage: 92% (Stent) versus 95% (POBA), p=n.s. Rand et al., Cardiovasc Intervent Radiol 2006;29(1):29-38
XXS Study Objective: Evaluation of safety and efficacy of XPERT stent vs. PTA in subjects with CLI Design: Prospective, randomized, two-arm, multi-center Subjects: 180 (90 Xpert : 100 PTA), Rutherford 4-6, maximum BTK lesion length: 15cm. Sites: 13 European Clinical Duplex ultrasound Angiography Baseline Proc. 24 hr 30 d 6 mo 12 mo Primary endpoint!! % Diameter stenosis (MLD) by angio @ 12 months Key Secondary endpoints! Procedural success, TLR @ 6 &12 months; TVR @ 6 &12 months;! Wound healing; & walking distance Source: www.clinical trials.gov; PI: G Tepe (Klinikum Rosenheim Institut für Diagnostische und Interventionelle Radiologie, Germany)
Commercially available DES Two randomized studies (positive).
ACHILLES Study! Cypher DES versus POBA (n=200 Rutherford 3 5 patients).! De novo or restenotic (after PTA only) lesion(s).! Total lesion length: <3cm.! Binary restenosis (ITT): 19.4% (DES) versus 41.9% (POBA), p=0.006. Scheinert D, CX Symposium 2011
DESTINY Study! Xience DES versus Multilink BMS (n=140 Rutherford 4 5 patients).! Total lesion length: <2cm.! Angiographic patency: 85.2% (DES) versus 54.5% (BMS), p<0.001.! TLR: 8.7% (DES) versus 33.6% (BMS), p<0.001.! Freedom from amputation: 98.7% (DES) versus 97.1% (BMS), p=n.s..
YUKON BTK Study! Polymer-free DES (Sirolimus) versus BMS (n=161 Rutherford 2 5 patients).! Total lesion length: 3 cm.! Angiographic patency: 80.6% (DES) versus 55.6% (BMS), p=0.004.! Clinical improvement (Rutherford) @ 1 year higher in DES group, p=0.004.! Event-free survival at 1 year: n.s..
Morphology of BTK lesions in CLI! Two thirds of all BTK lesions are occlusions.! 50% of all lesions are occlusions >10 cm. Graziani, et al. Eur J Vasc Endovasc Surg. 2007;33:453 460
Limitations of BTK Stents!! Late and very late stent thrombosis?! Permanent implant left behind.! Biomechanics not understood.! Stent fractures?
Biomechanics of BTK Arteries
Endovascular BTK Therapy in CLI Current Treatment Options Patient with Critical Limb Ischemia Focal lesion DES Long diffuse lesion PTA (DEB PTA?) Bailout Stenting End Calcified / Ostial / Focal AMS? DES Others SES?
Conclusions! DES associated with better patency compared to BMS or POBA for focal lesions.! Higher patency rates with BMS / DES do not translate into lower amputation rates.! Patency is only part of the answer to clinical success.! More randomized data for longer lesions needed.