Faculty Bibliography

Current changes that impact on vascular surgery include altered financial support, the introduction of endovascular treatments, and possible reentrance of general surgeons into the vascular field. In addition, vascular surgery in competition with interventional specialties (radiology and cardiology) for patients. These changes and the enhanced competition mandate that vascular surgery and vascular surgeons adapt by becoming competent with endovascular techniques to perform their standard operations better and to provide newer, better treatments that replace standard vascular operations. Vascular surgery must also resolve its conflicts with the American Board of Surgery (ABS) and the Residency Review Committee in Surgery (RRC-S) so that adequate numbers of well-trained vascular surgeons will be available to care for vascular disease patients optimally. Whether this can occur by modifying the present system or by having a separate board and residency review committee in vascular surgery will depend on the willingness of the ABS and the RRC-S to recognize that vascular surgery is a separate specialty that is best performed by those with special training and commitment to this field

Endovascular grafts (EVGs) have been proposed as a treatment for a variety of vascular diseases; however, the impact of EVGs on graft healing has not been fully evaluated. The aim of this study is to compare anastomotic intimal hyperplasia (AIH) and endothelialization in EVGs and conventional bypass grafts (CGs). Seven mongrel dogs received an EVG in one iliac artery and a CG in the other iliac artery using a 5 mm x 4 cm polytetrafluoroethylene graft. The EVG was secured to the native vessel wall, with balloon expandable stents at either ends of the graft. CGs were anastomosed using running sutures. Intravascular ultrasound was performed at the time of sacrifice (8 weeks) to determine percentage of stenosis at the distal anastomosis. Specimens were divided longitudinally for light microscopic analysis (thickness of distal AIH) and scanning electron microscopic studies (percentage of endothelial coverage of the graft). Percentage of stenosis at the distal anastomosis was significantly higher in EVGs compared with CGs (28.2 +/- 18.2% versus 1.8 +/- 2.8%; P < 0.01) due to significantly greater mean intimal thickness in the EVGs (441.1 +/- 101.1 microns versus 82.4 +/- 41.9 microns; P < 0.01). The total percentage of area covered by endothelial cells was also significantly greater in EVGs compared with CGs (80.5 +/- 37.5% versus 30.3 +/- 37.1%; P < 0.05). Intraluminal location enhanced endothelialization of the polytetrafluoroethylene graft; however, it also resulted in greater AIH. Further device refinements including stent design may be required to maximize the potential of these endovascular procedures

PURPOSE: Significant disease or occlusion of the common femoral artery may preclude percutaneous therapy for aorto-iliac occlusive disease. In addition, aorto-iliac angioplasty may not reverse the ischemic symptoms when common femoral artery disease exists. The authors describe the feasibility of endoluminal stent-grafts to treat multilevel aortoiliofemoral occlusive disease. MATERIALS AND METHODS: The authors placed 18 stent-grafts for aorto-iliac occlusive disease in 17 patients with limb-threatening ischemia and significant common femoral artery disease. These procedures were performed as a joint effort between vascular surgery and interventional radiology staff in the operating room. The common femoral artery was occluded in 10 or severely diseased in eight, necessitating endoluminal bypass to the superficial femoral or popliteal artery (n = 7) or to the deep femoral artery (n = 7), or necessitating patch angioplasty of the common femoral artery (n = 4). Stent-grafts were fabricated from 6-mm polytetrafluoroethylene and 29-mm Palmaz stents. RESULTS: All 18 grafts were placed successfully. Follow-up ranged from 3 to 38 months (mean, 21 months). Seven patients died of myocardial infarction; two grafts occluded and one required angioplasty during follow-up, resulting in a primary patency rate of 81% at 2 years. CONCLUSION: Endoluminal stent-graft placement is a useful method of treatment for advanced atherosclerotic aorto-iliac disease, particularly in the presence of common femoral artery disease. This approach avoids an extra-anatomic bypass or a major transabdominal aortic bypass procedure. Longer follow-up with a larger series is needed to ensure the safety and late graft patency comparable to the traditional aortofemoral and iliofemoral bypass grafts

PURPOSE: There are excellent arguments in favor of the preferential use of prosthetic grafts above the knee for the treatment of infrainguinal occlusive disease. This approach has been popularized on the basis of the seemingly acceptable results when using polytetrafluoroethylene (PTFE). However, in many centers, knitted Dacron polyester has been used in these patients, and there are several studies that show equivalent and, in some, superior results with Dacron when compared with PTFE. The purpose of this study was to examine these results in a definitive way. METHODS: A randomized prospective trial in eight clinical academic centers in the United States and Canada was initiated in 1991. Two hundred forty-four patients eligible for such a study, by virtue of criteria extant in each institution at the time, were centrally randomized. They underwent placement of either a knitted Dacron polyester graft impregnated with collagen or a thin-wall expanded reenforced PTFE graft to the above-knee popliteal artery, usually from the common femoral artery. They were frequently observed by protocol for as long as 5 years by a physical examination noninvasive hemodynamic study, including duplex scanning in many instances. Continuing patency was noted, as were other potential adverse outcome events. The data were analyzed by the log-rank test for cumulative patency and expressed as Kaplan-Meier curves. Data were further analyzed with a Cox proportional hazards model. RESULTS: There were no differences in graft groups in demographic or comorbid factors. The procedural mortality rate was zero, and the morbidity rate was low (6.5%). The long-term patient survival rate was excellent (77% at 3 years). At the end of these years, no statistical significance in primary or secondary patency rates was observed between the two grafts (primary patency rate, 62% +/- 14.4% for Dacron; 57% +/- 15.5% for PTFE). No unexpected adverse outcomes on limb status were noted. Patency rates in both graft groups were inferior in patients who received small grafts (5 to 6 mm vs 7 to 8 mm; hazards ratio, 4.15) and younger (<65 years) smoking patients. CONCLUSIONS: The fact that these two prosthetic grafts performed in equivalent fashion in a controlled, well-conducted prospective study is not surprising in spite of the previous work that suggested differences. If the preferential use of synthetic bypass grafts above the knee is to be used, it should be restricted to older nonsmokers with favorable anatomy. In that instance, the choice of graft material will depend on handling characteristics and cost. Above-knee prostheses should be only selectively used in younger, smoking patients, and graft size should be carefully considered in patients who undergo this operation