Time trends in the incidence rates of venous thromboembolism following colorectal resection by indication and operative technique

Aim: It is important for patient safety to assess if international changes in perioperative care, such as the focus on venous thromboembolism (VTE) prevention and minimally invasive surgery, have reduced the high post colectomy VTE risks previously reported. This study assesses the impact of changes in perioperative care on VTE risk following colorectal resection. Method: This was a population-based cohort study of colectomy patients in England between 2000 and 2019 using a national database of linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data. Within 30 days following colectomy, absolute VTE rates per 1000 person-years and adjusted incidence rate ratios (aIRRs) using Poisson regression for the per year change in VTE risk were calculated. Results: Of 183 791 patients, 1337 (0.73%) developed 30-day postoperative VTE. Overall, VTE rates reduced over the 20-year study period following elective (relative risk reduction 31.25%, 95% CI 5.69%–49.88%) but not emergency surgery. Similarly, yearly changes in VTE risk reduced following minimally invasive resections (elective benign, aIRR 0.93, 95% CI 0.90–0.97; elective malignant, aIRR 0.94, 95% CI 0.91–0.98; and emergency benign, aIRR 0.96, 95% CI 0.92–1.00) but not following open resections. There was a per year VTE risk increase following open emergency malignant resections (aIRR 1.02, 95% CI 1.00–1.04). Conclusion: Yearly VTE risks reduced following minimally invasive surgeries in the elective setting yet in contrast were static following open elective colectomies, and following emergency malignant resections increased by almost 2% per year. To reduce VTE risk, further efforts are required to implement advances in surgical care for those having emergency and/or open surgery.