Below-knee bypass using fresh arterial allografts for limb salvage: early results

Fresh arterial homograft for bypass in critical limb ischaemia with infection

We present what we believe is Australia's first fresh peripheral arterial transplant for revascularisation of an ischaemic limb. Although cryopreserved homografts are accepted as a management option for revascularisation of critical limb ischaemia in infected fields, cryopreserved peripheral vascular tissue is not currently available in Australia. We describe a 72-year-old man without autologous conduit in whom infected prosthetic grafts were explanted, causing critical limb ischaemia of a below knee stump. Fresh peripheral arterial tissue was procured via the Australian organ donation authority, DonateLife, and was used to revascularise the stump with an axillofemoral bypass. This permitted successful healing of the stump within 6 weeks and mobilisation with a prosthesis. This case illustrates that fresh arterial homografts are a viable bridging solution for revascularisation of limb ischaemia with infection. However, it also highlights the need to establish a peripheral homograft bank so that cryopreserved conduits are readily available for similar scenarios.

The seven-year' secondary patency of a fresh arterial allograft in the femorocrural position in a heart transplant recipient

Critical limb ischemia in patients with diabetes at the organ complication stage represents a considerable challenge in vascular medicine. Because of the complexity of the disease and the often symmetric involvement of both lower limbs, a discrepancy between suitable vascular conduit availability and the actual requirement can occur: notably, the prevalence of multilevel and diffuse arterial disease often limits the possibilities of endovascular treatment, and, in surgical cases, frequently prohibits the effective use of prosthetic material. In our patient with bilateral critical limb ischemia and previous coronary artery bypass graft followed by cardiac transplantation, only one great saphenous vein remained available. That was used in its entirety to salvage one limb as a sequential femorocrural bypass. A similar surgical procedure with a fresh arterial allograft retrieved from a deceased donor was performed on the other extremity . ABO compatibility as well as the chronic immunosuppressive therapy in a heart transplant recipient may have contributed to the favorable long-term clinical outcome of the allogeneic arterial reconstruction.

Uruguayan experience with cryopreserved arterial homografts

INTRODUCTION

We analyzed the Uruguayan experience with cryopreserved arterial homografts. We studied 55 medical records in the period from June 9, 2000 to April 7, 2007, including 41 from males and 14 from females, ranging from 36-78 years of age. The clinical indications were as follows: Group 1, revascularization of infrainguinal atherosclerotic occlusive disease by bypass due to the lack of availability of a suitable vein (n = 35); Group 2, substitution of an infected prosthetic grafts (n = 15); and Group 3, arteriovenous fistula (AVF) after failure of previous prosthetic loops by repeated thrombosis and/or infection in the absence of a vein (n = 5).

RESULTS

Among Group 1, primary and secondary patency rates were 61% and 71%, respectively at 1 year with 15 complications, 3 infections, 8 thromboses, 2 aneurysms, 1 homograft degradation, and 1 death related to surgery. Among Group 2, the primary and secondary patency rates were 71% and 79%, respectively, at 1 year with 6 patients experiencing complications. Group 3 did not have complications with a primary patency rate of 67% at 1 year.

CONCLUSIONS

The use of cryopreserved arterial homografts is a valid, accessible, and safe alternative in complicated vascular situations. In our country, it is a technology to consider for patients with critical limb ischemia, when the risk of a major amputation is high and it is not possible to have a suitable vein or prosthetic bypass. It can be an excellent alternative for the substitution of infected synthetic bypasses, especially to substitute in situ for an infected aortic graft.

Venous allografts preserved at 4 degrees C for infrainguinal bypass: long-term results from 170 procedures

From April 21, 1982 to December 31, 1997, we performed 170 infrainguinal bypass procedures using isolated (n = 35) or composite (n = 135) venous allografts preserved at 4 degrees C as a substitute for saphenous autografts in 146 patients. The mean age of the patient population was 74 years. The indication was critical lower limb ischemia in 71% of cases. Seventy-five percent of procedures were below the knee and 26% were infrapopliteal. Mean length and diameter were 19.5 +/- 0.5 cm and 4.8 +/- 0.5 mm, respectively. After December 8, 1993, a reinforcement net was placed over the graft to prevent expansion in 71% of cases. Primary and secondary 5-year patency, calculated according to the Kaplan-Meier method, were 33 +/- 6% and 43 +/- 6%, respectively. Factors correlated with secondary patency were studied using the log-rank test. Previous ipsilateral infrainguinal revascularization was associated with a 40% decrease in secondary patency at 2 years (71% vs. 31%). Patency at 5 years was correlated with the level of anastomosis (47% for low popliteal anastomosis vs. 30% for infrapopliteal anastomosis). The likelihood of stenosis or dilatation of the allograft was 8% and 29.5%, respectively, at 5 years. The 5-year limb salvage and survival rates were 84% and 57%, respectively. The encouraging results of this series suggest that venous allografts provide a useful alternative for infrainguinal bypass when autologous grafts or other more reliable conduits are unavailable.