Diabetes as an independent risk factor for early postoperative complications in critical limb ischemia

The purpose of this study was to evaluate the significance of diabetes mellitus as a risk factor for postoperative major morbidity and mortality after surgery for critical lower limb ischemia (CLI).

A national vascular registry (Finnvasc)-based survey included 5709 operations for CLI from 1991 through 1999. Of these operations, 2508 (44%) were performed on diabetics. Tissue loss was the indication for surgery in 77% of diabetics and in 52% of nondiabetics. The proportion of femorodistal bypasses was 43% in diabetics and 24% in nondiabetics, whereas the proportion of reconstructions for aortofemoral arterial occlusive disease was 16% in diabetics and 34% in nondiabetics.

Thirty-day mortality was 4.5% in diabetics and 3.4% in nondiabetics ( P = .05). The rate for early below-knee amputation was 6.5% in diabetics and 3.3% in nondiabetics ( P < .001). Independent factors for postoperative death were aortofemoral reconstruction (odds ratio [OR], 4.0), preoperative cardiac risk factor (OR, 3.1), primary surgery (OR, 2.0), renal insufficiency (OR, 1.9), urgent surgery (OR, 1.7), and age (OR, 1.3). Diabetes was an independent risk factor for postoperative below-knee amputation (OR, 1.7), cardiac complications (OR, 1.5), and superficial wound infection (OR, 1.3). There was an inverse association between diabetes and acute graft occlusion (OR, 0.8). Independent risk factors for early postoperative mortality in diabetes were aortofemoral reconstruction (OR, 2.5), urgent surgery (OR, 2.0), male gender (OR, 2.0), renal insufficiency (OR, 1.9), cardiac risk factor (OR, 1.7), and age (OR, 1.4). In nondiabetics independent risk factors for early postoperative mortality were aortofemoral reconstruction (OR, 4.5), cardiac risk factor (OR, 3.6), primary surgery (OR, 2.6), and extra-anatomic bypass (OR, 2.3).

Diabetes was not an independent risk factor for early postoperative mortality in CLI as there was an increased morbidity in diabetics associated with old age, male gender, known coronary artery disease, and renal insufficiency, as well as urgent surgery. As diabetics have increased proclivity for these factors, special attention needs to be paid to their preoperative assessments.