Venous thromboembolism and transfusion after major abdominopelvic surgery

BACKGROUND: Thromboprophylaxis aims to reduce venous thromboembolism but has the potential to increase bleeding. We sought to evaluate the risk of venous thromboembolism and transfusion after major abdominopelvic procedures and to quantify the association of the procedure with venous thromboembolism. METHODS: The American College of Surgeons' National Surgical Quality Improvement Program was queried for patients who received an abdominopelvic surgery between 2005 and 2016. Patient factors, operative factors, and outcomes were collected. Multivariable analyses were used to determine the association between individual procedures and venous thromboembolism. Area under the curve analyses were performed to assess whether addition of the procedure to Caprini score improved the association of the model with venous thromboembolism. The primary outcome was risk of venous thromboembolism within 30 days of surgery. Secondary outcomes were the risk of transfusion within 30 days and the association between operative time with venous thromboembolism. RESULTS: There were 896,441 patients who received an abdominopelvic procedure. The overall risk of venous thromboembolism was 1.9% (n = 16,665). Procedures with the highest risk of venous thromboembolism were esophagectomy (5.5%) and partial esophagectomy (5.3%). The overall risk of transfusion was 9.5% (n = 84,889). Procedures with the highest risk of transfusion were pelvic exenteration (53.6%) and radical cystectomy (37.7%). On multivariable analyses, individual procedures were independently associated with venous thromboembolism, despite adjusting for Caprini score. Area under the curve analyses indicated risk prediction of the baseline model (area under the curve 0.59) improved when procedures were added (area under the curve 0.68). CONCLUSION: Patients undergoing abdominopelvic surgery are at a high risk of venous thromboembolism and transfusion. Improved risk stratification may be possible by including more procedural information in scoring systems.