Minor amputation after revascularization in chronic limb-threatening ischemia: What is the optimal timing?

Objectives: Patients with chronic limb-threatening ischemia (CLTI) have a high risk of lower limb amputation and loss of walking independence. Minor amputations play a key role in ensuring walking independence and they represent a challenge in terms of timing and level for vascular surgeons. A major cause of re-amputation is a defect in wound healing and a possible predictor of re-amputation for non-healing wounds could be the incorrect timing of minor amputation after revascularization. The lack of evidence in the literature leads to a wide variability of choices in clinical practice. The purpose of this study was to try to find the optimal timing analysing the risk of re-amputation in CLTI patients who have undergone successful revascularization and minor amputation focussing on timing of minor amputation.

Methods: We conducted a single centre retrospective analysis on a cohort of 151 patients consecutively admitted to our hospital for CLTI (Rutherford 5) between January 2014 and April 2022. All the enrolled patients underwent successful revascularization of lower limbs and a minor amputation for dry acral necrosis. The characteristics of the patients and the revascularization procedures were collected and analysed. Patients were divided into two groups based on the timing of minor amputation performed before (group 1) or after the day (group 2) that best predicts the risk of re-amputation according to a Receiver Operating Characteristic (ROC) curve analysis. The primary outcome of this study was the risk of re-amputation during the first 60 days of follow-up after a primary minor amputation, with revascularization still effective. The impact of the timing of minor amputation after revascularization, the type of revascularization and the presence of risk factors known to prolong the wound healing process were evaluated in a uni- and multi-variable logistic regression model.

Results: Systemic hypertension, and type of revascularization (i.e. open vs endovascular) were independent predictors of the risk of re-amputation at 60 days (HR 4.26, 95% CI 1.30-14.04, p = .017 and HR 2.35, 95% CI 1.16-4.78, p = .018, respectively). Moreover, time ≤14 days between revascularization and first amputation was associate with a clear, albeit not statistically significant, trend toward increased risk of re-amputation (HR 2.09, 95% CI 0.97-4.51, p = .06).

Conclusions: In a cohort of patients who underwent a successful revascularization for CLTI and a minor amputation for dry gangrene in the first 14 days after revascularization, a higher -although not significant-risk of re-amputation was reported. In this cohort of patients, a delayed demolitive procedure should be considered to allow better tissue perfusion and to reduce the risk of re-amputation.