A Series of 210 Peripheral Arterial Disease Below-Knee Amputations and Predictors for Subsequent Above-Knee Amputations

Objective: To review patient characteristics and outcomes after peripheral arterial disease (PAD)-related below-knee amputation (BKA), and identify risk factors predicting subsequent above-knee amputation (AKA). Materials and Methods: A retrospective study of 210 BKAs between May 2008 and December 2015. Results: The mean age of the study population was 66 years. Most of the patients had cardiovascular comorbidities, and 33% had end-stage renal failure (ESRF); 89% were American Society of Anesthesiologists 3 or 4. Previous ipsilateral lower-limb minor amputation was present in 49% and previous contralateral lower-limb major amputation was present in 20% patients. Limb salvage revascularization via angioplasty prior to BKA was performed in 73%, while 27% had extensive tissue loss that was not suitable for limb salvage. Postoperatively, 20% had BKA wound infection, with 3% requiring further surgical debridement, and 9% (19 patients) required subsequent AKA within 1 month. Overall survival analysis at 1-5 years was 75%, 66%, 64%, 59%, and 58%, respectively. Multivariate analysis showed ESRF (Odds Ratio [OR]=3.85; p=0.01) and preoperative non-ambulatory status (OR=5.58; p=0.01) to be independent risk factors in predicting for subsequent AKA. Conclusion: Patients with underlying ESRF or preoperative non-ambulatory status may benefit from direct AKA if major amputation is required.