Incidence of Deep Venous Thrombosis (DVT) Postoperatively Following Major Lower Limb Amputation in Patients on Prophylactic Anticoagulation

Abstract Background: Deep venous thrombosis (DVT) is part of a spectrum of venous thromboembolic disorders that includes superficial thrombophlebitis and pulmonary embolism. DVT may be defined as “the formation of a blood clot within a deep vein”. Although many studies have considered venous thromboembolism (VTE) in clinical and surgical patients, few have focused on patients who have undergone amputation of the lower extremities because of peripheral arterial disease (PAD). Few prospective research studies with a sufficiently large amputee patient sample have considered the incidence of deep venous thrombosis (DVT) in the early postoperative period. Data from existing studies are divergent, and the incidence of VTE is highly variable, ranging from 0% to 66.66%. Aim of Study: The aim of this study is to prospectively document the incidence of DVT complicating major lower extremity amputation (above and below knee amputation) in patients using prophylactic anticoagulants. Patients and Methods: The prospective study involved 35 patients underwent unilateral lower limb amputation. The mean age was 45±8.8 years (range: 18 to 55 years). They were 19 males (54.29%), and 16 females (45.71%), with ratio of 1.2: 1. Patients received prophylactic anticoagulant (Apixa-ban 2.5mg twice daily) immediately postoperatively and for 6 weeks, assessment after 3 & 6 weeks was done using duplex to exclude presence of DVT. Results: There was no statistically significant difference between incidence of DVT and site of amputation, as 5/15 patients (33.3%) who underwent to BKA developed DVT, while 10/20 patients (50%) who underwent to AKA, developed DVT [HR: 1.6 (95%CI: 0.4-6.5), p=0.487]. Infection was associated with higher incidence of patients who developed post-operative DVT, as 11/15 patients (73.3%) had history of infection caused amputation, developed DVT, p-value = 0.002. Using venous duplex after 3 weeks from surgery, revealed that 9/15 patients (60%) who underwent AKA developed DVT, while 2/20 patients (10%) who underwent BKA developed DVT (p=0.001). Assessment after 6 weeks revealed that 3/20 patients (15%) who underwent BKA developed DVT, while 1/15 patient (6%) who underwent AKA developed DVT (p=0.6), with no statistically significant difference, thus emphasize that AKA was associated with early higher incidence of DVT rather than BKA. Conclusion: DVT is a common complication following major lower limb amputation. And preoperative infection is considered main risk factor and increase risk of DVT. Occur-rence of DVT is more in patients with AKA than others with BKA. Using prophylactic anticoagulants decrease risk of DVT up to 50%. And using of DOACs shows non-significant difference from other types of anticoagulants.