Multicenter Randomized Prospective Trial Comparing a Pre-cuffed Polytetrafluoroethylene Graft to a Vein Cuffed Polytetrafluoroethylene Graft for Infragenicular Arterial Bypass Jean M. Panneton, MD,1 Larry H. Hollier, MD,2 and Jan M. Hofer, RN, BSN,1 Rochester, Minnesota and New York, New York
Poor patency of synthetic grafts for infragenicular revascularization has led to use of distal vein patches or cuffs. The aim of this study was to compare the distally widened DistafloTM PTFE graft, which mimics a vein cuff, with a PTFE graft with distal vein modification. In this prospective, randomized, multicenter trial we compared use of a precuffed PTFE graft wit that of PTFE grafts with distal vein modification for infragenicular revascularization in patients with critical limb ischemia without saphenous vein. Study end points were primary and secondary patency and limb salvage rates at 2 years. From January 28,1999 to November 1, 2000, 104 patients were enrolled in 10 North American centers. Thirteen were excluded for protocol violation. Ninety-one bypasses were performed in 89 patients with a mean age of 73 years (range 47-90). By randomization, 47 bypasses were done with the precuffed graft and 44 with PTFE graft with vein cuff. Both groups were comparable for comorbidities and operative variables, except for a higher incidence of acute ischemia in the precuffed group (19% vs. 4.5%, p = 0.03). Bypass was a redo procedure in 53% and was performed at the infrapopliteal vessels in 79%. Operative mortality was 2.2% (2/91). Mean follow-up was 14 months (range 1-30). At 1 and 2 years, primary patency was 52% and 49% for the precuffed group and 62% and 44% for the vein cuffed group, respectively (p = 0.53). At 1 year and 2 years, the limb salvage rate was 72% and 65% for the precuffed group and 75% and 62% in the vein cuffed group (p = 0.88). Although numbers are small and follow-up short, this midterm analysis shows similar results for the Distaflo precuffed grafts and PTFE grafts with vein cuff. A precuffed graft is a reasonable alternative conduit for infragenicular reconstruction in the absence of saphenous vein and provides favorable limb salvage.
INTRODUCTION The poor results of synthetic arterial bypasses for infragenicular vessels have already been estab1
Division of Vascular Surgery, Mayo Clinic, Rochester, MN, USA.
2
Division of Vascular Surgery, Mount Sinai Medical Center, New York, NY, USA. Presented at the Twenty-eighth Annual Meeting of the Peripheral Vascular Surgery Society, Chicago, IL, June 7, 2003. See Appendix 1 for list of DistafloTM trial investigators and participating centers. Correspondence to: Jean M. Panneton, MD, Division of Vascular Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA, E-mail:
[email protected] Ann Vasc Surg 2004; 18: 199-206 DOI: 10.1007/s10016-004-0012-y Annals of Vascular Surgery Inc. Published online: 15 March 2004
lished.1 Because of these abysmal results, many adjunctive techniques such as vein modification at the distal anastomosis have been proposed to improve infragenicular synthetic bypasses. Many authors have reported improved patency with the use of these vein collars, boots, and patches.2-5 A prospective, randomized trial from the United Kingdom showed an improved graft patency rate for expanded polytetrafluoroethylene (ePTFE) bypasses done with a Miller cuff at the below-knee level, compared to synthetic graft done without any vein cuff.6 The rationale behind the use of such vein modification has been to try to decrease the occurrence of myointimal hyperplasia at the level of the distal anastomosis.7 The creation of a precuffed PTFE graft to mimic a vein cuff at the distal anastomosis was done to obtain improved flow hemo199
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dynamics at the level of the distal anastomosis. The Impra DistafloTM PTFE graft (Bard Peripheral Vascular Inc., Tempe, AZ) represents such a precuffed graft that applies the concept of anastomotic engineering (Fig. 1).8 This study was undertaken with the hypothesis that a precuffed graft (Distaflo) could obtain similar graft patency and limb salvage rates to those with a PTFE graft with a vein modification at the distal anastomosis in patients requiring infragenicular arterial bypasses.
METHODS The trial design was a multicenter prospective, randomized study comparing use of a precuffed ePTFE graft (Impra Distaflo) with that of a vein cuffed ePTFE graft for infragenicular arterial bypasses. This trial was industry-sponsored by Bard Peripheral Vascular, Inc., a subsidiary of CR Bard, Inc. (Murray Hill, NJ). A total of 15 North American centers were selected to participate in this trial. The patients enrolled in this study were to be selected by the investigators for a problem of chronic lower limb ischemia that should be treated with a synthetic ePTFE graft with or without a vein cuff. Patients had to meet strict inclusion and exclusion criteria to be eligible. The inclusion criteria included male and female patients between 18 and 90 years of age who had evidence of peripheral arterial occlusive disease with symptoms of chronic critical limb ischemia, such as rest pain, nonhealing ulceration, or gangrene, and in whom the autologous greater saphenous vein was unsuitable or unavailable. Patients were to understand and give informed consent. Claudicators and above-knee reconstructions were specifically excluded from this study. When patients satisfied all inclusion and exclusion criteria and gave their informed consent, they were then randomized at the time of their lower extremity bypass procedure to receive either a precuffed ePTFE graft or a standard PTFE graft with a vein modification of the choice of the investigator, such as a Taylor patch, a Linton patch, or a Miller cuff. An angiographic score was calculated for each revascularized limb by counting the number of arterial segments and the degree of atherosclerotic occlusive disease. The following arterial segments were included in this calculation: superficial femoral, above-knee popliteal, below-knee popliteal, peroneal, anterior tibial, posterior tibial, and pedal arteries. The following grade was assigned to each of the segments: 0 if
