Long-term results of a multicenter randomized study on direct versus crossover bypass for unilateral iliac artery occlusive disease.

OBJECTIVE: To compare late patency after direct and crossover bypass in good-risk patients with unilateral iliac occlusive disease not amenable to angioplasty.

METHODS: Between May 1986 and March 1991, 143 patients with unilateral iliac artery occlusive disease and disabling claudication were randomized into two surgical treatment groups, ie, crossover bypass (n = 74) or direct bypass (n = 69). The size of the patient population was calculated to allow detection of a possible 20% difference in patency in favor of direct bypass with a one-sided alpha risk of 0.05 and a beta risk of 0.10. Patients underwent yearly follow-up examinations using color flow duplex scanning with ankle-brachial systolic pressure index measurement. Digital angiography was performed if hemodynamic abnormalities were noted. Median follow-up was 7.4 years. Primary endpoints were primary patency and assisted primary patency estimated by the Kaplan-Meier method with 95% confidence interval. Secondary endpoints were secondary patency and postoperative mortality and morbidity.

RESULTS: Cardiovascular risk factors, preoperative symptoms, iliac lesions TASC class (C in 87 [61%] patients and D in 56 [39%] patients), and superficial femoral artery (SFA) run-off were comparable in the two treatment groups. One patient in the direct bypass group died postoperatively. Primary patency at 5 years was higher in the direct bypass group than in the crossover bypass group (92.7 +/- 6.1% vs 73.2 +/- 10%, P = .001). Assisted primary patency and secondary patency at 5 years were also higher after direct bypass than crossover bypass (92.7 +/- 6.1% vs 84.3 +/- 8.5%, P = .04 and 97.0 +/- 3.0% vs 89.8 +/- 7.1%, P = .03, respectively). Patency at 5 years after crossover bypass was significantly higher in patients presenting no or low-grade SFA stenosis than in patients presenting high-grade (> or =50%) stenosis or occlusion of the SFA (74.0 +/- 12% vs 62.5 +/- 19%, P = .04). In both treatment groups, patency was comparable using polytetrafluoroethylene (PTFE) and polyester grafts. Overall survival was 59.5 +/- 12% at 10 years.

CONCLUSION: This study showed that late patency was higher after direct bypass than crossover bypass in good-risk patients with unilateral iliac occlusive disease not amenable to angioplasty. Crossover bypass should be reserved for high-risk patients with unilateral iliac occlusion not amenable to percutaneous recanalization.