Outcome of infra-inguinal bypass grafts using vein conduit with less than 3 millimeters diameter in critical leg ischemia.

OBJECTIVE: The purpose of this study was to evaluate the difference in amputation-free survival and patency rates of infra-inguinal bypass grafts in patients with critical leg ischemia (CLI) with vein conduits with an internal diameter <3 mm compared to those with vein conduits with a diameter of ≥ 3 mm.

METHODS: Retrospective analysis of all consecutive patients with CLI undergoing infra-inguinal bypass. Preoperative duplex scan mapping and measurement of potential vein grafts were performed on all patients. Patients were recruited in a 1-year duplex scan graft surveillance program. Primary end points were amputation-free survival and patency rates at 1 year postoperatively. Kaplan-Meier and χ(2) test were used for statistical analysis.

RESULTS: Between January 2004 and April 2010, 157 consecutive patients with CLI underwent 171 bypasses using vein conduits (111 men, 46 women; median age, 75 years; range, 45-96 years). Ninety-three bypasses (54.4%) were performed for tissue loss, 44 (25.7%) for gangrene, and for rest pain. Of the 157 patients, 113 (72.0%) had diabetes mellitus, 40 (25.5%) had renal impairment, 131 (83.4%) had hypertension, and 64 (40.8%) had ischemic heart disease. Femoro-popliteal bypass was performed in 38 cases (22.2%), whereas 133 (77.8%) of the bypasses were femoro-distal. Autogenous great saphenous vein (GSV) was used in all cases. All grafts were reversed. The diameter of 31 (18%) vein conduits measured <3 mm (range, 2-2.9 mm) on preoperative duplex scan. One hundred thirty-four grafts had at least 1-year follow-up. The primary, assisted primary, and secondary patency rates at 1 year for vein conduits <3 mm were 51.2%, 82.6%, and 82.6%, respectively, compared to 68.4%, 93.3%, and 95.2%, respectively, in the ≥ 3 mm group. This was only significant for the secondary patency (P = .0392). The amputation-free survival at 48 months was 70.8% for vein conduits <3 mm and 57.3 for vein conduits ≥ 3 mm.

CONCLUSION: This series has shown that primary and assisted primary patency rates in small veins are not significantly different at 1 year but the secondary patency rates are better in the larger veins. Similarly, the amputation-free survival was also comparable. The authors would, therefore, advocate the use of small veins >2 mm in diameter in patients with CLI. Duplex scan surveillance followed by early salvage angioplasty for threatened grafts is needed to achieve good patency rates in both groups.