The quality of evidence is downgraded by inconsistency (unexplained variability in results), and by imprecise results (wide confidence intervals).
A Cochrane review included 11 studies with a total of 1 486 subjects. Six studies compared bypass surgery with percutaneous transluminal angioplasty (PTA) and one each with remote endarterectomy, thromboendarterectomy, thrombolysis, exercise, and spinal cord stimulation. No studies comparing bypass surgery with no intervention or medical treatment were identified.
Bypass surgery compared with PTA: There were no differences between bypass surgery and angioplasty in periprocedural mortality (OR 1.67, 95% CI 0.66 to 4.19; 5 studies, n=913), clinical improvement (OR 0.65, 95% CI 0.03 to 14.52; 2 studies, n=154), amputation rates (OR 1.24, 95% CI 0.82 to 1.87; 5 studies, n=752), reintervention rates (OR 0.76, 95% CI 0.42 to 1.37; 3 studies, n=256), or mortality within the follow-up period (OR 0.94, 95% CI 0.71 to 1.25; 5 studies, n=961). Early non-thrombotic complications tended to occur more frequently in participants undergoing bypass surgery, but the difference did not reach statistical significance (OR 1.29, 95% CI 0.96 to 1.73; 6 studies, n=1 015). Analyses by different clinical severity of disease (intermittent claudication=IC or critical lower limb ischaemia=CLI) revealed that early postoperative non-thrombotic complications occurred more frequently in participants with CLI undergoing bypass surgery than PTA (OR 1.57, 95% CI 1.09 to 2.24). Bypass surgery was more often technically successful (OR 2.26, 95% CI 1.49 to 3.44; 5 studies, n=913), was associated with longer hospital stay, and the bypass graft remained open (patent) at a higher rate 1 year after the procedure compared with angioplasty (OR 1.94, 95% CI 1.20 to 3.14; 4 studies, n=300), but this difference was not shown at 4 years (OR 1.15, 95% CI 0.74 to 1.78; 2 studies, n=363).
Bypass surgery compared with remote endarterectomy, thromboendarterectomy, thrombolysis, exercise, and spinal cord stimulation: There were no clear differences between bypass surgery and other treatments in procedural complications and deaths, clinical improvement, vessel patency, and long-term mortality. Comparisons of bypass surgery with thrombolysis showed fewer amputations in patients with bypass surgery (OR 0.10, 95% CI 0.01 to 0.80; 1 study, n=236), whereas for the rest of the comparisons the amputation rate was similar. Technical success resulting in blood flow restoration was higher after bypass surgery than thromboendarterectomy for aorto-iliac occlusive disease (OR 0.01, 95% CI 0 to 0.17; 1 study, n=43).
A Cochrane review