Long-term assessment of cryopreserved vein bypass grafting success

Transcription

1 Long-term assessment of cryopreserved vein bypass grafting success Linda Harris, MD, a Monica O Brien-Irr MS, RN, a and John J. Ricotta, MD, b Buffalo, NY Purpose: When autogenous vein is unavailable, cryopreserved veins have been used in patients as a means of attempted limb salvage. We evaluated the long-term patency and limb salvage rates for patients undergoing bypass grafting with cryopreserved veins. Methods: Medical records were reviewed for patients undergoing cryovein bypass grafting at two hospitals from 1992 to Follow-up data were obtained from subsequent admissions and office records. Primary outcomes were death, amputation, and primary patency. Skin integrity and additional bypass grafting procedures were assessed when data were available. Analysis was performed by means of life-table and χ 2 analyses with the Statistical Package for Social Sciences (SPSS). Results: Seventy-six patients (mean age, 70 ± 11 years) underwent 80 procedures. Indications for surgery were tissue loss (63%), rest pain (24%), acute ischemia (11%), and other (2%). Early complications included 3 deaths (4%), 14 acute thromboses (18%), and 7 major amputations (9%). The mean follow-up period was 17.8 ± months (range, 0-77 months). The primary patency rate was determined to be 36.8% at 1 year and 23.6% at 3 years by means of life-table analysis. The limb salvage rate was 65.5% at 1 year and 62.3% at 3 years. Skin integrity was found to be compromised in 17 (55%) of 31 patients who were available to follow-up. Nine patients (11.3%) underwent additional ipsilateral revascularization or revisions, with one of three of these patients eventually requiring a major amputation. Conclusion: Cryopreserved vein may be a reasonable alternative conduit for limb salvage when no autogenous tissue is available; it has an acceptable limb salvage rate (62.3%) at 3 years. Long-term patency remains relatively poor, with only 23.6% of originally placed grafts patent at 3 years. The use of cryopreserved veins should be strictly confined to limb salvage after a thorough search for autogenous tissue has been exhausted. (J Vasc Surg 2001;33: ) Autologous saphenous vein remains the ideal conduit for lower extremity revascularization. However, the saphenous vein is not always available for distal reconstruction because of earlier harvesting for coronary bypass grafting or lower extremity revascularization, removal for varicosities, inadequate vein size, previous phlebitis, or structural defects within the vein. In as many as 20% of patients, the ipsilateral saphenous vein is not available or suitable for grafting. 1 The next option for many surgeons is contralateral saphenous vein and then alternative veins, including the cephalic vein, basilic vein, and lesser saphenous veins. In 10% of patients, no autogenous tissue is available for distal reconstruction. 1,2 Prosthetic grafts have been used with reasonable success in the above-knee position, but they have relatively poor results when used for distal revascularizations. 3-5 Multiple techniques have been proposed to augment the patency of the prosthetic grafts, including arteriovenous fistula or a variety of cuffs or patches with small pieces of vein at the distal anastomosis. 6-8 Nonetheless, prosthetic grafts remain a poor alternative for distal reconstructions. From KALEIDA Health, Millard Fillmore Hospital, Department of Surgery, State University of New York, Buffalo, a and the Department of Surgery, State University of New York, Stony Brook. b Competition of interest: nil. Reprint requests: Linda Harris, MD, KALEIDA Health/Millard Fillmore Hospital, Department of Surgery, 3 Gates Circle, Buffalo, NY Copyright 2001 by The Society for Vascular Surgery and The American Association for Vascular Surgery /2001/$ /1/ doi: /mva The lack of a suitable substitute for the greater saphenous vein has led to the exploration of other biological tissues, including umbilical vein and gluteraldehyde or freeze-dried saphenous vein. Most recently, interest has again arisen in the use of cryopreserved saphenous vein as an alternative for distal revascularization in patients without adequate autogenous vein. We have evaluated the long-term patency and limb-salvage rates for patients undergoing bypass grafting procedures with cryopreserved vein grafts. METHODS Medical records of all patients undergoing lower extremity bypass grafting with cryopreserved vein at two teaching hospitals between 1992 and 1997 were retrospectively reviewed. Patients who had undergone more recent bypass grafting procedures were not evaluated because of the short period of follow-up available. Patients undergoing implantation of cryopreserved veins into locations other than the lower extremities were also excluded from the review. Demographics, comorbidities, indications, outflow vessels, previous vascular procedures, and outcomes were documented. Comorbidities included coronary artery disease, hypertension, diabetes mellitus, cerebrovascular disease, hypercholesterolemia, and current smoking. Follow-up data were obtained from subsequent admissions and office records. Duplex graft surveillance frequency varied because of physician preference. Primary outcomes were death, primary graft patency, and amputation. Skin integrity and additional bypass grafting procedures were assessed when data were available. Statistical

2 Volume 33, Number 3 Harris, O Brien-Irr, and Ricotta 529 Fig 1. Life-table analysis of cumulative patient survival rate. analysis was performed by means of life-table and χ 2 analyses with SPSS (Statistical Package for Social Sciences), with significance taken when the P value was less than.05. RESULTS Seventy-six patients (mean age, 70 ± 11 years; range, years) underwent 80 procedures. Thirty-seven patients (49%) were men. Comorbidities included coronary artery disease (39%), hypertension (36%), diabetes mellitus (54%), cerebrovascular disease (19%), hypercholesterolemia (20%), and current smoking (18%). Almost half the patients (46%) had undergone an earlier ipsilateral bypass grafting procedure. Indications for surgery were tissue loss (63%), rest pain (24%), acute ischemia (11%), and other (2%). Other indications included infection. Outflow vessels included the popliteal (31%), tibial (60%), and plantar (9%). The patient survival rate was 90.8% at 1 year and 63.4% at 3 years (Fig 1). Early complications occurred after 17 bypass grafting procedures (21%) and included 3 deaths (4%), 14 acute thromboses (18%), and 7 major amputations (9%). Postoperative occlusion was a predictor of limb loss (P =.00007), with 71% of patients (10 of 14) with postoperative occlusion undergoing major amputation within 6 months of surgery. The remaining four patients (29%) with postoperative occlusion had viable limbs at a mean of 4.8 months postoperatively. However, two of these patients had no evidence of healing of their original tissue loss 5 months after surgery. The mean follow-up period was 17.8 ± months (range, 0-77 months). The primary patency rate, as documented with duplex examination, was 36.8% at 1 year and 23.6% at 3 years by means of life-table analysis (Fig 2). Data were insufficient to make determinations about differences in cumulative patency for femoral popliteal versus femoral distal bypass grafts, because of sample size. The overall limb salvage rate was 65.5% at 1 year and 62.3% at 3 years (Fig 3). Incidence of major amputation was significantly increased with femoral distal bypass grafting, as opposed to femoral popliteal bypass grafting (49% vs 12% at 3 years; P =.02; Fig 4). Additional bypass grafting procedures were completed in 11.3% of patients (9 of 80). The limb salvage rate at 6 months did not differ significantly in patients with primarily patent grafts versus patients with secondarily patent grafts (93.4% vs 100%; P =.16). However, one third of patients who underwent additional ipsilateral revascularization eventually required a major amputation. A significant difference in limb salvage rate was seen between primarily patent grafts and occluded grafts that were not subjected to additional procedures (93.4% vs 45.2%; P =.0001). Additionally, a significant difference was noted between secondarily patent grafts and occluded grafts (100% vs 45.2%, P =.04; Fig 5). Ulceration was seen in 17 (55%) of 31 patients who were available for follow-up. Five of those patients (16%) were documented to have no evidence of healing of the original tissue loss within 6 months of surgery. New tissue loss was demonstrated in the remaining patients during the course of follow-up. The bypass graft was occluded in most patients with ulceration (11 of 17). DISCUSSION Short-term reports have often suggested widely varying outcomes for allograft bypass grafts Fewer series that analyze long-term outcomes are available. Further confounding the analysis of outcome are differences in methods of preservation. Old data are based on different

3 530 Harris, O Brien-Irr, and Ricotta March 2001 Fig 2. Life-table analysis of cumulative primary patency rate of cryopreserved vein bypass grafts. Fig 3. Life-table analysis of limb-salvage rate. techniques of cryopreservation with different cryoprotectant solutions. Uniformity in cryopreservation techniques still does not exist. Although techniques are not as varied, with most cryopreserved veins being purchased from one of several major commercial sources, there are still differences between these companies that may have an impact on short- and long-term outcomes. Other confounding factors are variability in patient population between series and the use of pharmacological adjuncts, including warfarin and various immunosuppressive agents. Short-term patency rates from recent series in the literature range from 28% to 80% at 1 year and fall to between 19% and 42% at 2 years. Complications related to implantation of cryopreserved venous allografts include an early failure rate (fewer than 30 days) of 17% and a late aneurysm formation rate of between 5% and 33% in reported series Unfortunately, there are still relatively few studies with any long-term results, which makes conclusions on longterm patency data difficult. We found a long-term patency

4 Volume 33, Number 3 Harris, O Brien-Irr, and Ricotta 531 Fig 4. Life-table analysis of cumulative limb-salvage rate for femoral popliteal versus distal bypass grafting procedures (P =.02). Fig 5. Life-table analysis of cumulative limb-salvage rate for primarily patent, secondarily patent, and occluded bypass grafts. Primarily patent versus secondarily patent, P =.16; primarily patent versus occluded without additional bypass, P =.0001; secondarily patent versus occluded without additional bypass, P =.04. BPG, Bypass graft; OCCL, occlusive. rate of 23.6% at 3 years, with a 62.3% rate of limb salvage. Further, additional attempts at revascularization for occluded grafts did not improve the overall limb salvage rate in the long term. The outcome of limb salvage surgery in the absence of suitable autologous saphenous vein depends greatly on the material used for bypass grafting It is difficult to appropriately compare cryopreserved vein bypass grafts with prosthetic bypass grafts, because there are no randomized trials comparing the two conduits. In historical studies, surgeons may preferentially use allograft vein for patients with disadvantaged outflow or more distal sites, thereby making comparisons questionable. Patency rates of prosthetic to below-knee popliteal bypass grafts range from 44% to 60% 3,5,20,23,24 at 5 years. However, patency rates of prosthetic bypass grafts to tibial vessels has generally been unsatisfactory, with only a 12% to 22% patency rate at 5 years. 3 Cryopreserved vein grafts may be a reasonable alternative to prosthetic grafts for limb salvage procedures when no autogenous tissue is available. Limb salvage rates are acceptable, both in the short term and the long term. However, skin integrity may remain compromised or recur, casting doubts on the long-term efficacy of bypass grafting with cryopreserved veins. The use of cryopreserved veins should be confined to limb-salvage procedures. Cryopreserved veins should be used only after a thorough search for autogenous tissue has been exhausted. Further, the use of polytetrafluoroethylene

5 532 Harris, O Brien-Irr, and Ricotta March 2001 grafts with adjunctive cuffs or patches should be strongly considered before implantation of a cryopreserved graft. REFERENCES 1. Kent KC, Whittemore AD, Mannick JA. Short-term and midterm results of an all autogenous tissue policy for infrainguinal reconstruction. J Vasc Surg 1989;9: Gentile AT, Lee RW, Moneta GL, Taylor LM, Edwards JM, Porter JM. Results of bypass to the popliteal and tibial arteries with alternative sources of autogenous vein. J Vasc Surg 1996;23: Abbott WM. Prosthetic above-knee femoral-popliteal bypass: indications and choice of graft. Semin Vasc Surg 1997;10: Veith FJ, Gupta SK, Ascer E, White-Flores S, Samson RH, Scher LA, et al. Six-year prospective multicenter randomized comparison of autologous saphenous vein and expanded PTFE grafts in infrainguinal arterial reconstructions. J Vasc Surg 1986;3: Dalman RL, Taylor LM. Basic data related to infrainguinal revascularization procedures. Ann Vasc Surg 1990;4: Taylor RS, Loh A, McFarland RJ, Cox M, Chester JF. Improved technique for polytetrafluoroethylene bypass grafting: long-term results using anastomotic vein patches. Br J Surg 1992;79: Miller JH, Foreman RK, Fergusson L, Faris I. Interposition vein cuff for anastomosis of prosthesis to small artery. Aust N Z J Surg 1984;54: Tyrrell MR, Wolfe JHN. eptfe grafts and a venous boot. Perspectives in Vascular Surgery 1993;6: Faggioli G. Cryopreserved vein homografts. Eur J Vasc Surg 1994;8: Fujitani RM, Bassiouny HS, Gewertz BL, Glagov S, Zarins CK. Cryopreserved saphenous vein allogenic homografts: an alternative conduit in lower extremity arterial reconstruction in infected fields. J Vasc Surg 1992;15: Posner MP, Makhoul RG, Altman M, Kimball P, Cohen N, Sobel M, et al. Early results of infrageniculate arterial reconstruction using cryopreserved homograft saphenous conduit (CADVEIN) and combination low-dose systemic immunosuppression. J Am Coll Surg 1996;183: Shah RM, Faggioli GL, Mangione S, Harris LM, Kane J, Taheri SA, et al. Early results with cryopreserved saphenous vein allografts for infrainguinal bypass. J Vasc Surg 1993;18: Walker PJ, Mitchell RS, McFadden PM, James DR, Mehigan JT. Early experience with cryopreserved saphenous vein allografts as a conduit for complex limb-salvage procedures. J Vasc Surg 1993;18: Harris RW, Schneider PA, Andros G, Oblath RW, Salles-Cunha S, Dulawa L. Allograft vein bypass: is it an acceptable alternative for infrapopliteal revascularization? J Vasc Surg 1993;18: Selke FW, Meng RL, Rossi NP. Cryopreserved saphenous vein homografts femoral-distal vascular reconstruction. J Cardiovasc Surg 1989;30: Leseche G, Penna C, Bouttier S. Femorodistal bypass using cryopreserved venous allografts for limb salvage. Ann Vasc Surg 1997;11: Martin RS, Edwards WH, Mulherin JL Jr. Cryopreserved saphenous vein allografts for below-knee lower extremity revascularization. Ann Surg 1994;219: Gournier JP, Favre JP, Gay JL. Cryopreserved arterial allografts for limb salvage in the absence of suitable saphenous vein: two-year results in 20 cases. Ann Vasc Surg 1995;9(Supp):S CryoLife Inc. Clinical research department communication Jakobsen HL, Baekgaard N, Christoffersen JK. Below-knee popliteal and distal bypass with PTFE and vein cuff. Eur J Vasc Endovasc Surg 1998;15: Tyrell MR, Rampling MW, Wolfe JH, Chester JF, Taylor RS. PTFE, collars, and patches. J Invest Surg 1992;5: Tyrell MR, Wolfe JHN. New prosthetic venous collar anastomotic technique: combining the best of the other procedures. Br J Surg 1991;78: Raptis S, Miller JH. Influence of a vein cuff on polytetrafluoroethylene graft for primary femoropopliteal bypass. Br J Surg 1995;82: Stonebridge PA, Prescott RJ, Ruckley CV. Randomized trial comparing infrainguinal polytetrafluoroethylene bypass grafting with and without vein interposition cuff at the distal anatomosis. J Vasc Surg 1997;26: Submitted Mar 30, 2000; accepted Jun 22, 2000.