Graft type for femoro-popliteal bypass surgery

Background

Vascular surgeons construct femoro-popliteal bypass grafts, from the groin to the knee, to save limbs that might otherwise require amputation in patients with severe arterial disease, and to improve walking distance in patients with less severe arterial disease. During the operation, the blocked native artery is bypassed using either a section of the patient's own vein (autologous vein), human umbilical vein (HUV), or an artificial graft e.g. Dacron or polytetrafluoroethylene (PTFE).

Objectives

To determine the most effective type of graft for femoro-popliteal bypass surgery.

Search strategy

The Cochrane Peripheral Vascular Diseases Group searched their Specialised Register, and the authors searched reference lists of relevant articles, and hand searched proceedings from the British and European Vascular Surgical Societies and the North American Society of Vascular Surgery. They also contacted all major manufacturers of artificial grafts and authors of published trials to enquire about unpublished trials.

Selection criteria

Randomised trials comparing one type of femoro-popliteal graft with another.

Data collection and analysis

Both reviewers selected trials and assessed trial quality independently.

Main results

Nine trials were included with a total of 1334 participants. These investigated a variety of graft types.

In one trial of above-knee grafting, primary and secondary patency were significantly better for saphenous vein (73% and 90%, respectively) compared to PTFE (47%, p<0.05 and 47%, p<0.05) and Dacron (54%, p<0.01 and 60%, p<0.01) at four years.

Two trials comparing in-situ and reversed saphenous vein grafts to the above- and below-knee popliteal artery revealed no differences in primary patency (64% v 62% respectively), secondary patency (65% v 70%), or survival with intact limb (74% both groups) with five to ten year follow-up.

Three trials comparing PTFE with HUV showed significantly better secondary patency rates for HUV, (41% v 73%, p<0.005; 49% v 66%, p<0.05; 22% v 42%,p=0.005) one also showed significantly better primary patency for HUV at five years (32% v 65%, p<0.001).

Comparison of PTFE grafts with, and without, a vein cuff found no difference in above-knee grafts. However, primary patency below-knee was higher with a PTFE plus vein cuff bypass (52% v 29%, p=0.03) at two years.

Authors' conclusions

There is no clear evidence which type of graft is best for femoro-popliteal grafting. In terms of autologous graft patency, in-situ and reversed vein grafts are equally successful, while HUV performs better than PTFE. A distal vein cuff may improve primary patency for below-knee PTFE femoro-popliteal grafts.