Synchronous reconstruction for combined aortoiliac and femoropopliteal occlusive lesions. The role of proximal bypass. Between January 1984 and December 1986, 31 patients underwent synchronous revascularization (SR) because of the serious clinical condition of a lower limb and presence of arteriographically visible lesions. Average follow-up was 30 months. Operative mortality was 10%. Two patient populations were identified: Group I (N = 13): patients who underwent ilio-femoral or aorto-femoral proximal revascularization (PR); Group II (N = 18): patients who had axillo-femoral PR. Group I patients were younger than those in Group II (64 yr versus 72 yr; p less than 0.01). An association of pre-operative risk factors (arterial hypertension; coronary, renal or respiratory insufficiency) was twice as frequent in Group II as in Group I (p less than 0.02). The rate of SR compared to PR alone was 15%. However, there was no statistically significant difference between Groups I and II. Comparison of the actuarial survival curves for patients ahd the patency rates of SR in Groups I and II failed to reveal any statistically significant differences. Axillo-femoral bypass can be used for PR when SR is necessary in high risk patients. 