Prophylaxis extension for venous thromboembolism after major abdominal and pelvic surgery for cancer (prevent): Quality improvement transitioned into a cohort study.

Abstract

Extended venous thromboembolism prophylaxis after abdominopelvic cancer surgery has not been widely adopted. We compared outcomes of patients pre- and postimplementation of extended venous thromboembolism prophylaxis with low molecular weight heparin. Prospectively collected data from a quality initiative project aimed at prescribing extended venous thromboembolism prophylaxis after abdominopelvic cancer surgery was compared with previously published data from a prospective cohort without extended venous thromboembolism prophylaxis. The primary outcome was 6-month postoperative symptomatic venous thromboembolism incidence. differences in 1- and 3-month venous thromboembolism incidence and factors associated with venous thromboembolism using Cox-proportional hazard models. Cumulative incidence of venous thromboembolism was estimated using Kaplan-Meier methods and expressed as proportions with 95% confidence interval. There were 241 patients in the venous thromboembolism-prophylaxis cohort and 284 patients in the no venous thromboembolism prophylaxis cohort. Patients in the venous thromboembolism-prophylaxis cohort were more likely to be female (69% vs 60%, P = .018), have metastatic disease (49% vs 29%, P < .001), have longer operative times (236 min vs 197 min, P < .001), and to receive neoadjuvant chemotherapy (27% vs 23%, P = .006). Respectively, the 1- (0.5% [95% confidence interval, 0.1-2.5] vs 0.4% [95% confidence interval, 0.1-2.5]), 3- (2.6% [95% confidence interval, 1.2-5.6] vs 2.5% [95% confidence interval, 1.2-5.2]), and 6-month (7.5% [95% confidence interval, 4.8-11.5] vs 7.2% [95% confidence interval, 4.7-11.0]) venous thromboembolism incidence were similar. By multivariable analysis, history of venous thromboembolism (hazard ratio 3.52; 95% confidence interval, 1.03-12.05; P = .045) and longer duration of hospital stay (hazard ratio 1.07; 95% confidence interval, 1.01-1.12; P = .016) demonstrated increased risk of venous thromboembolism. This study failed to demonstrate a decreased 1-, 3-, and 6-month postoperative venous thromboembolism incidence after the implementation of extended venous thromboembolism prophylaxis.