Objective: To assess the impact of current guidelines by reporting weekly postoperative postdischarge venous thromboembolism (VTE) rates. Summary Background Data: Disparity exists between the postoperative thromboprophylaxis duration colectomy patients receive based on surgical indication, where malignant resections routinely receive 28 days extended thromboprophylaxis into the postdischarge period and benign resections do not. Methods: English national cohort study of colectomy patients between 2010 and 2019 using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data. Stratified by admission type and surgical indication, absolute incidence rates (IRs) per 1000 person-years and adjusted incidence rate ratios (aIRRs) for postdischarge VTE were calculated for the first 4 weeks following resection and postdischarge VTE IRs for each postoperative week to 12 weeks postoperative. Results: Of 104,744 patients, 663 (0.63%) developed postdischarge VTE within 12 weeks after colectomy. Postdischarge VTE IRs per 1000 person-years for the first 4 weeks postoperative were low following elective resections [benign: 20.66, 95% confidence interval (CI): 13.73–31.08; malignant: 28.95, 95% CI: 23.09–36.31] and higher following emergency resections (benign: 47.31, 95% CI: 34.43–65.02; malignant: 107.18, 95% CI: 78.62–146.12). Compared with elective malignant resections, there was no difference in postdischarge VTE risk within 4 weeks following elective benign colectomy (aIRR=0.92, 95% CI: 0.56–1.50). However, postdischarge VTE risks within 4 weeks following emergency resections were significantly greater for benign (aIRR=1.89, 95% CI: 1.22–2.94) and malignant (aIRR=3.13, 95% CI: 2.06–4.76) indications compared with elective malignant colectomy. Conclusions: Postdischarge VTE risk within 4 weeks of colectomy is ∼2-fold greater following emergency benign compared with elective malignant resections, suggesting emergency benign colectomy patients may benefit from extended VTE prophylaxis.
