The views presented reflect those of the author/presenter and do not necessarily reflect those of ASDIN nor serve as an endorsement of safety, efficacy or applicability of said procedure. the Endovascular Stents and Stent Grafts: What to Do and What Not to Do Bart Dolmatch, MD The Palo Alto Medical Foundation El Camino Hospital Mountain View, CA DISCLOSURE Industry Relationships Bard Peripheral Vascular, Inc.: Royalties, Paid Consultant and Speaker Bureau Vital Access, Inc.: Medical Advisory Board Member Merit Medical Systems, Inc.: Consultant VASA: Board of Directors The Endovascular Forum: Medical Advisory Board Off label use of stents and covered stents Stents: By the book K-DOQI GUIDELINE 19 Stenoses that occur in a dialysis AV graft or primary AV fistula should be treated with percutaneous transluminal angioplasty or surgical revision... K-DOQI GUIDELINE 19, con t. Stents are useful for selected instances when PTA fails*. 1. limited residual access sites 2. surgically inaccessible lesions 3. contraindication to surgery The unassisted patency of stents in hemodialysis access is no better than that following PTA, except in elastic stenoses. What does this mean? A successful stent is better than a failed (recoiled) angioplasty! *PTA Failure: Recoil >30% stenosis or more than 2 PTA s within 3 mo. NKF K/DOQI GUIDELINES 2000 1
Other often-accepted indications for a stent 1. Treatment of PTA-induced venous rupture 2. After AV Graft declot PTA of the venous anastomosis (Maya et al 2006, Sreenarasimhaiah et al 2005) 8mm Nitinol Stent 7 months after stent salvage In-stent Restenosis 2
So, stents bail out PTA, but they Increase cost In-stent restenosis Patency = successful PTA Wallstent (1995) 46% 6-month1 0 patency 20% 12-month 1 0 patency Wallstent Gray RJ, Horton KM, Dolmatch BL, et al. Radiology 1995;195:479-484 Wallstent (2009) More recently: Nitinol stents in AVG s 39% 6-month 1 0 patency 51% 6-mo 1 0 patency <20% 12-month 1 0 patency central <20% 12-mo 1 0 patency Smart Stent Wallstent Kariya S, et al. CVIR 2009; 32:960 966 Vogel PM, Parise C. J Vasc Interv Radiol 2004; 15:1051 1060 How about PTA vs 1 0 Stent? >50% stenosis AND dysfunction PTA only PTA + Stent Stents are no better than angioplasty PTA vs PTA/Stent primary patency 30% 6-month 1 0 patency <20% 12-month 1 0 patency Gianturco Stent Quinn SF, et al. JVIR 1995;6:851-855 3
Stent Grafts The Flair (Bard Peripheral Vascular) (AV Graft Venous Anastomosis) Viabahn FLARED Flair Viatorr Fluency STRAIGHT 6 mo. Primary Patency Results 16 mo Stent Graft PTA p- value Treatment Area 1 0 Patency 50.55% (46/91) 23.26% (20/86) <0.001 Access Circuit 1 0 Patency 38.04% (35/92) 19.77% (17/86) 0.008 4
The Flair: Bottom Line The Flair nearly doubled AVG circuit patency compared to PTA, alone. FDA has cleared Flair for AVG s Medicare will pay when used as indicated (including primary use) Other potential (controversial) uses of stent grafts in AV access AVF venous stenoses Aneurysms/pseudoaneurysms In-stent or in-stent-graft restenosis PTA-related rupture Central Vein obstruction Long segment stenoses (unsalvageable) Fluency Stent Graft Salvage of Dysfunctional Hemodialysis Access B.L. Dolmatch 1, J.M. Duch 3, L.M. Kershen 1, R. Winder 1, S. Josephs 1, C.K. Trimmer 1, J. Lopera 1, I. Davidson 2 1) Radiology, UT Southwestern Medical Center, Dallas, TX, USA 106 Fluency-treated patients 138 Fluency Stents Placed 125 Sites Combination of AV Grafts and AV Fistulae AVF: n=43 (40.6%) AVG: n=58 (54.7%) Unknown: n=5 (4.7)% 2) Surgery, UT Southwestern Medical Center, Dallas, TX, USA 3) Lincoln Nephrology and Hypertnesion, Lincoln, NE, USA. Indication for Covered Stent Primary Circuit Patency 1. 00 n=81 (76%) post-pta Stenosis (>30%, operator Defined) n=14 (13%) Recurrent Stenosis (within 3 mos. of PTA) n=22 (21%) Contrast Extravasation (Rupture) n=4 (4%) Presence of Pseudoaneurysm 0. 75 0. 50 0. 25 62.0% 34.9% Legend o o o o AVF AVG 0. 00 (p = 0.010) 0 25 50 75 100 125 150 175 200 Pr i mar y Ci r cui t Pat ency Days STRATA: Graf t_fi stul a=fi stul a Censored Graft_Fi st ul a=fi stul a Graf t_fi stul a=graft Censored Graft_Fi st ul a=graft Log-Rank p- val ue = 0. 010 5
Cumulative Circuit Patency B-B AVF Swing point Stenosis after declot 6.5 months 1. 00 88.0% 0. 75 71.9% Legend Post-PTA 0. 50 o o AVG o o AVF 13 months 0. 25 8x80 Fluency (p = 0.061) 0. 00 0 25 50 75 100 125 150 175 200 Cumul at i ve Ci r cui t Pat ency Days STRATA: Gr af t _Fi st ul a=fi st ul a Censor ed Gr af t _Fi st ul a=fi st ul a Gr af t _Fi st ul a=graft Censor ed Gr af t _Fi st ul a=graft Log-Rank p- val ue = 0. 061 Brachiocephalic AVF Short Occluded Segment 8mm x 6cm Fluency Cannulation pseudoaneurysms: OK? Fluency at 6 mo 6
8 month follow-up with good thrill 10mm covered stents at cannulation zone 7mm PTA Immediate post-pta rupture Long stenoses: Unsalvageable AV Fistulae? Initial 8mm x 5cm Viabahn 3 mo GRAFTULA (AV Fistula Significantly Altered with Graft-Covered Stents) 7
1 year follow-up (Fluency and Viabahn): Working at 14 months renal transplant The stent grafts we use today aren t optimized for many anatomic locations 1. Extrinsic compression no BES s 2. Around curves and angles 3. Across joints 4. In cannulation segments 5. Central veins ONLY use self-expanding stents and stent grafts! It s a crushed balloon expandable stent graft (placed at AVG pseudoan) pseudoaneurysm Beware of curves and angles Fracture and stenosis due to extrinsic compression and fatigue in the deltopectoral groove 8
Beware at flexion points (elbow) 6 months 6 months NO flexion across the elbow In a Cannulation Segment Vesely TM. J Vasc Interv Radiol 2005; 16:1301 1307 Vesely TM. J Vasc Interv Radiol 2005; 16:1301 1307 Stents and Stent Grafts: What to do and not to do: 1. DON T 1 0 stent: First use PTA or surgery 2. DO bail out PTA - but consider if patency will be better with stent or stent-graft 3. DON T use balloon expandable stents/stent grafts 4. DO use Flair (stent graft) for appropriate AVG venous anastomosis (FDA and Medicare OK) 5. ALWAYS consider options 1. Early follow up (no stent or stent graft) 2. Revision surgery 3. New AV access 9
Before you rush off to use stents and stent grafts Think of the downside and upside. And with all implantable devices, remember Safety first. 10