Thirty-Year Trends in Aortofemoral Bypass for Aortoiliac Occlusive Disease

Objective

Endovascular intervention has supplanted open bypass as the most frequently used approach in patients with aorto-iliac segment atherosclerosis. We sought to determine whether this trend together with changing demographic and clinical characteristics of patients undergoing aorto-bifemoral bypass (ABFB) for aorto-iliac occlusive disease (AOD) has an association with postoperative outcomes.

Methods

Using a prospectively maintained institutional database, we identified patients who underwent ABFB for AOD from 1985 to 2015. Patients were divided into two cohorts: the historical cohort (HC) included patients who underwent ABFB for AOD from 1985 to 1999 and the contemporary cohort (CC) who underwent ABFB for AOD from 2000 to 2015. Medical and demographic data, procedural information, postoperative complications, and follow-up data were extracted. Cox proportional hazards regression was used to evaluate associations with the endpoint of primary patency. A similar analysis was performed for major adverse limb events (MALEs; the composite of above-ankle amputation, major re-intervention, graft revision, or new bypass graft of the index limb) in the subset of patients with critical limb ischemia.

Results

There were a total of 359 cases: 226 in the HC and 133 in the CC. The CC had more women (56.4% vs. 43.8%; P <0.02), smokers (87.2% vs. 67.7%; P <0.001), and patients who failed prior aorto-iliac endovascular intervention (17.3% vs. 4.8%; P <0.0001), but fewer patients with coronary artery disease (32.3% vs. 47.3%; P <0.005). 30-day mortality was less than 1% in both cohorts, but 10-year survival was higher in the CC (67.7% vs. 52.6%; P <0.02). 5-year primary, primary-assisted, and secondary patency were higher in the HC (93.3% vs. 82.2%; P <0.005; 93.8% vs. 85.7%; P <0.02; 97.5% vs. 90.4%; P <0.02, respectively). CC membership, decreasing age, prior aortic surgery, and decreasing graft diameter were significant independent predictors of loss of primary patency after adjustment (hazard ratio [HR], 7.03; 95% confidence interval [CI], 2.80–17.63; P <0.0001; HR, 0.93; 95% CI, 0.90–0.96; P <0.0001; HR, 18.80; 95% CI, 5.94–59.58; P <0.0001; and HR, 0.73; 95% CI, 0.55–0.95; P <0.02, respectively). Similarly, CC membership, prior aortic surgery, and 96decreasing graft diameter were significant independent predictors of MALE in the critical limb ischemia cohort after adjustment (HR, 21.13; 95% CI, 4.20–106.40; P <0.0002; HR, 40.40; 95% CI, 3.23–505.61; P <0.004; and HR, 0.51; 95% CI, 0.30–0.86; P <0.01, respectively).

Conclusions

Compared with the pre-endovascular era, demographic and clinical characteristics of patients undergoing ABFB for AOD in the CC have changed. Although long-term patency is slightly lower among patients in the CC during which a substantial subset of AOD patients are being treated primarily via the endovascular approach, durability remains excellent and limb salvage unchanged. After adjustment, the time period of index ABFB independently predicted primary patency and MALE, as did graft diameter and prior aortic surgery. These changing characteristics should be considered when counseling patients and benchmarking for re-intervention rates and other outcomes.