Risk factors for reamputation in patients with diabetic foot: A case-control study

Abstract

Background: Reamputation as a complication of diabetic foot ulcers presents a high economic burden and represents a therapeutic failure. It is paramount to identify as early as possible patients in whom a minor amputation may not be the best option. The purpose of this investigation was to do a case-controlled study to determine risk factors associated with re-amputation in patients with DFU (diabetic foot ulcers) at two University Hospitals.

Methods: Multicentric, observational, retrospective, case-control study from clinical records of 2 university hospitals. Our study included 420 patients, with 171 cases (re-amputations), and 249 controls. We performed a multivariate logistic regression analysis and time-to-event survival analysis to identify re-amputation risk factors.

Results: Statistically significant risk factors were artery history of tobacco use (p = 0.001); male sex (p = 0.048); arterial occlusion in Doppler ultrasound (p = 0.001); percentage of stenosis in arterial ultrasound >50 % (p = 0.053); requirement of vascular intervention (p = 0.01); and microvascular involvement in photoplethysmography (p = 0.033). The most parsimonious regression model suggests that history of tobacco use, male sex, arterial occlusion in ultrasound, and percentage of stenosis in arterial ultrasound >50 % remained statistically significant. The survival analysis identified earlier amputations in patients with larger occlusion in arterial ultrasound, high leukocyte count, and elevated ESR.

Conclusion: Direct and surrogate outcomes in patients with diabetic foot ulcers identify vascular involvement as an important risk factor for reamputation.

Level of evidence: III.

Keywords: Diabetic foot; Diabetic foot ulcer; Infection; Lower extremity amputation; Reamputation; Survival analysis.