Delayed Closure of Guillotine Lower Extremity Amputation in Obese Patients is Associated with Increased Mortality

Abstract

OBJECTIVEStaged surgery with open guillotine amputation (OGA) prior to a definitive major lower extremity amputation (LEA) has been shown to be effective for sepsis control and improving wound healing. Studies have evaluated postoperative complications including infection, return to the operating room for re-amputation, and amputation failure following OGA. However, the role of timing to close OGA for predictive outcomes remains poorly understood. We aim to assess outcomes of major LEA related to the time of OGA closure. METHODSData from patients who underwent major LEA from 2015 to 2021 was collected retrospectively. The study included all patients undergoing below-, through-, or above-knee amputations. Next, patients who had OGA prior to a definitive amputation were selected. Patients who died before amputation closure were excluded. Post-amputation outcomes such as surgical site infection (SSI), postoperative sepsis, postoperative ambulation, hospital length of stay (LOS), and 30-day, 1-year, and 5-year mortality were reviewed. The study cohort was stratified by demographics and comorbidities. Receiver operating characteristic (ROC) curve analysis was performed to determine the time of closure (TOC) cut-off value. Univariate and multivariate analysis was performed to assess outcomes. Statistical significance was set at p < 0.05. RESULTOf 688 patients who underwent major LEA, 322 underwent staged amputation with OGA before the formalization procedure and were included. The TOC ranged from 1-47 days with a median of 4 days (interquartile range (IQR) from 3 to 7). The optimal TOC point of 8 days (ranging from 2 - 42 days) in obese patients (199/322) for predicting mortality showed the largest area under the curve (AUC) (0.709) with 64.71% sensitivity and 78.3% specificity. Patients who are obese and grouped in TOC less than 8 days had no 30-day mortality, significantly lower 1-year mortality, better survival, and a lower rate of deep venous thrombosis (DVT) complication. There was no significant difference in LOS, postoperative SSI, sepsis, and ambulation between the two subgroups of obese patients. Multivariable analysis showed that gender, CKD, and postoperative ambulation independently predict overall mortality in obese patients. CONCLUSIONTOC cutoff in obese patients showed statistically significant results in predicting mortality. Our findings indicated better survival in obese patients with a lower TOC (less than 8 days). This emphasizes the importance of earlier closure of OGA in obese patients.