Analysis of Patients Undergoing Major Lower Extremity Amputation in the Vascular Quality Initiative

Background: Despite an aggressive climate of limb salvage and revascularization, 7% of patients with peripheral artery disease undergo major lower extremity amputation (LEA). The purpose of this study was to describe the current demographics and early outcomes of patients undergoing major LEA in the Vascular Quality Initiative (VQI). Methods: The VQI amputation registry was reviewed to identify patients who underwent major LEAs. Patient factors, limb characteristics, procedure type, and intraoperative variables were analyzed by the level of amputation. Factors associated with amputation level, 30-day complications, and mortality were analyzed using chi-squared analysis for significance with associated P values. Propensity score adjustment was used to balance statistically significant differences observed in subject characteristics by amputation level for the associated relative risk of a given outcome. Results: Between 2013 and 2015, 2,939 major LEAs were recorded in the VQI amputation registry. The ratio of below-knee to above-knee amputation (BKA: AKA) was 1.29: 1. The mean age was 66 years, 64% were male, 84% lived at home before admission, and 68% were ambulatory. Comorbidities included diabetes (67%), coronary artery disease (32%), end-stage renal disease (22%), and chronic obstructive pulmonary disease (23%). The mean preoperative ankle-brachial index (ABI) was 0.78. Overall, 43% had a history of prior ipsilateral revascularization. Indications for amputation were ischemic rest pain or tissue loss (58%), uncontrolled infection (31%), acute ischemia (9%), and neuropathic tissue loss (2%). The overall perioperative complication rate was 15%, 25% were discharged home, and the 30-day mortality was 5%. Patients who received an AKA versus BKA were more likely to be female (40.61% vs. 31.70%), more than age 70 (48.79% vs. 32.55%), underweight (18.63% vs. 9.18%), nonambulatory (40.22% vs. 25.18%), have an ABI < 0.6 (58.00% vs. 45.26%), and carry nonprivate insurance (77.40% vs. 69.08%) (all P < 0.001). Patients undergoing AKA were less likely to have 30-day postoperative complications (12.24% vs. 17.87%) but had higher 30-day mortality (6.70% vs. 3.09%) than BKA patients (all P < 0.001). Conclusions: In the VQI registry, major LEA was performed predominantly for ischemic rest pain and tissue loss with a BKA: AKA ratio of 1.29: 1. Patients undergoing AKA versus BKA were older, had lower ABI, lower rates of 30-day postoperative complications but higher rates of 30-day mortality. This registry offers an important real-world resource for studies pertaining to vascular surgery patients undergoing major lower extremity amputation.