Risk factors for mortality after below knee amputation in patients with diabetes

Area of Science:

• Vascular Surgery
• Diabetology
• Public Health

Background:

• Diabetic foot ulcers often require major lower-extremity amputation, including below-knee amputation (BKA), when limb salvage fails.
• Despite being a source-control measure, BKA in diabetic patients is associated with high postoperative mortality rates.

Purpose of the Study:

• To identify preoperative demographic, clinical, and laboratory factors associated with mortality after primary below-knee amputation (BKA) in diabetic patients.
• To evaluate short- and intermediate-term all-cause mortality following BKA in this high-risk population.

Main Methods:

• Retrospective cohort study analyzing 1,487 patients with diabetes undergoing primary BKA.
• Mortality was assessed at 30, 90, 180, and 365 days post-operation.
• Multivariate logistic regression identified independent predictors of mortality.

Main Results:

• Non-survivors were older, had higher Charlson Comorbidity Index scores, and lower serum albumin levels.
• Independent predictors of increased mortality included chronic kidney disease (CKD), albumin <2.95 g/dL, elevated WBC count (>13.805 × 10⁹/L), Charlson Comorbidity Index >5.5, and oral vs. IV antibiotics post-operatively.

Conclusions:

• Preoperative comorbidities (CKD, high comorbidity burden) and laboratory markers (hypoalbuminemia, elevated WBC) significantly increase mortality risk after BKA in diabetic patients.
• Comprehensive preoperative assessment and targeted perioperative strategies are crucial for improving outcomes in this vulnerable patient group.