Purpose: Biological material has been used as an alternative to autogenous vein since the first lower extremity revascularization procedures were performed. Our experience with glutaraldehyde-tanned human umbilical cord vein graft (UVg), which spanned a period of 28 years, forms the basis of this report, with an emphasis on comparative results between the two decades from 1975 to 1985 and from 1990 to 2000.
Methods: Between 1990 and 2000, 283 lower extremity bypass grafting procedures were performed in 230 patients (264 limbs), with UVg used as the predominant, or sole, graft material. Our experience with 907 reconstructions in the decade from 1975 to 1985 has been previously documented and now serves as a baseline comparison with the past decade of experience with UVg. Each reconstruction was classified on the basis of the distal anastomotic site with or without distal arteriovenous fistulas (dAVFs). The primary and secondary graft patency rates were determined for each category as was cumulative palliation, which combines the end points of graft failure, amputation, and death.
Results: The results from the second decade (1990 to 2000) showed a continuation of improving patency rates for UVg grafts in lower extremity revascularization. Comparison results of complications showed no changes in the low incidence rates of infection, stenosis, dissection, and pseudoaneurysm. The original series results showed a 2.9% requirement for aneurysm surgery, with an incidence rate of biodegradation of 57% (36% aneurysms, 21% dilation), whereas the current series results have shown no aneurysms to date. The comparative 6-year secondary patency rates for past and current popliteal and crural bypass grafts (with or without dAVF) were: popliteal, 53% versus 67%, P <.05; and crural, 26% without dAVF versus 47% with dAVF, P <.05. The limb salvage rates for the two series at 6 years showed no significant changes between the decades and the types of bypass grafts. Thrombolysis was performed during the decade from 1990 to 2000 in 27 UVg cases, with lysis achieved in 23 cases (85%) and limb salvage achieved in 20 cases (74%). Since 1996, associated endovascular procedures (fluoroscopy, angioplasty) have assumed increasing importance in the reduction of perioperative graft closure and in the enhancement of patency.
Conclusion: Our continuing experience with UVg confirms that favorable results can be obtained with this biologic alternative to autologous vein for lower limb revascularization. Concern regarding biodegradation and aneurysm formation even after 5 years are unfounded at this time. Improved patency and limb salvage rates can be achieved in concert with lower nonthrombotic failure rates, increasing performance of associated endovascular procedures, use of tourniquets, and the addition of dAVF for crural bypass grafting. Prospective randomized studies are still necessary for the assessment of the comparative role of all graft materials, a project that continues to evade our specialty.