Unrecognized Arteriosclerosis Is Associated with Wound Complications after Below-Knee Amputation

Abstract

Guillotine below-knee amputation (BKA) for wet gangrene is an unfortunate complication of poorly controlled diabetes. We examined risk factors associated with wound complications after amputation formalization in this patient population. Retrospective data over a 4-year period were collected for patients undergoing guillotine BKA for wet gangrene followed by staged formalization. Patients with abnormal distal pulses underwent evaluation before formalization to stratify for peripheral arterial disease (PAD). Those patients with palpable pulses and no known PAD went to formalization without further investigation. Poor operative candidates underwent delayed formalization to allow for preoperative optimization. Patient history, interval between surgeries, pathology, and preformalization laboratories were tested for significance. Primary outcome was postformalization wound complication. Fifty-six amputations in 55 patients met inclusion criteria. Wound complications after formalization occurred in 18 cases, all BKAs (32%). A history of PAD was present in 19 patients (34.5%). On pathology, 23 patients (41%) had small-vessel atherosclerosis or arteriosclerosis. There was no association between wound complications and history of PAD (P = 0.4), preformalization albumin (P = 0.09), glucose (P = 0.9), white blood cell count (P = 0.4), or delayed versus expedited formalization (P = 0.8). Only the presence of microvascular disease on formal pathology was predictive of wound complications (P = 0.03). There was no association between microvascular disease on pathology and a history of PAD (P = 0.07). After formalization of lower extremity amputation for wet gangrene, traditional markers of PAD were not predictive of wound complications. Although formalization of guillotine BKA can safely be performed without significant delay, more thorough assessment of microvascular disease in the perioperative period may be useful in identifying patients at risk for wound failure.