All-Cause Mortality Amongst Patients Undergoing Above and Below Knee Amputation in a Regional Vascular Centre within 2014-2015

BACKGROUND: Major lower limb amputation remains a common treatment for patients with peripheral vascular disease (PVD) in whom other measures have failed. It has been associated with high morbidity and mortality, including risks from venous thromboembolism (VTE). METHODS: A two-year retrospective cohort study was conducted involving 79 patients who underwent major lower limb amputation (below- or above-knee amputation) between January 2014 and December 2015 in a single tertiary referral centre. Amputation procedures were performed for reasons relating to complications of PVD and/or diabetes mellitus. Patients were followed-up to investigate all-cause mortality rates and VTE events using the Northern Ireland Electronic Care Record database (mean follow-up time 17 months). RESULTS: Of the 79 patients, there were 52 male and 27 female. Mean age at time of surgery was 72 years (range 34-99 years). Forty-six patients (58%) suffered from diabetes mellitus, 29 (35%) heart failure, 31 (39%) chronic kidney disease (CKD) and 10 (13%) chronic obstructive pulmonary disease (COPD). Twenty patients (25%) were on anticoagulant therapy, and 53 (67%) were on antiplatelet therapy. Thirty-five patients (44%) died during follow-up; mean age at death was 74 years. No statistically significant association was found between mortality rate and the level of amputation (p=0.3702), gender (p=0.3507), or comorbid diabetic mellitus (p=0.1127), heart failure (p=0.1028), CKD (p=0.0643) or COPD (p=0.4987). Two patients experienced radiologically-confirmed non-fatal pulmonary emboli and two patients developed radiologically-confirmed deep vein thrombosis. CONCLUSIONS: The results are in agreement with current literature that amputation is associated with significant mortality, with almost half of the study population dying during follow-up. Further work should explore measures by which mortality rates may be reduced.