Results of aortic bifurcation grafts for aortoiliac occlusive disease: A meta-analysis

Purpose: To summarize mortality, morbidity, and long-term patency data of bifurcated aortoiliac or aortofemoral bypass graft procedures in aortoiliac occlusive disease. Methods: A Medline search was performed of the medical literature published between 1970 and 1996. Studies were included if (1) they reported patency rates based on life tables and the number at risk was provided at yearly intervals; and (2) patient and study characteristics were reported in sufficient detail. Mortality and morbidity risks were pooled using a fixed-effects model. The patency data were combined using a technique that enables adjustment for differences across studies in patient characteristics or reporting methods. In the current analysis, we corrected for the symptomatic status of the patients at the time of surgery (claudication vs ischemia) and the unit of observation used in reporting the patency (limb vs patient). Results: We identified 23 studies that met the inclusion criteria. The aggregated operative mortality risk in the older studies (started before 1975) was 4.6%, as compared with 3.3% in the more recent studies (p = 0.01). The aggregated systemic morbidity risk was 13.1% in the older studies and 8.3% in the more recent studies (p < 0.001). Limb-based patency rates for patients with claudication were 91.0% and 86.8% at 5 and 10 years, respectively, as compared with 87.5% and 81.8% for patients with ischemia. Patency rates reported in the older studies were markedly similar to those of more recent studies (p = 0.58). Conclusions: Our study suggests that mortality and systemic morbidity rates of aortic bifurcation graft procedures have dropped since 1975, whereas patency rates seem to be fairly constant over the years.