Venous thromboembolism after major urologic oncology surgery: a focus on the incidence and timing of thromboembolic events after 27,455 operations.

OBJECTIVE: To investigate the incidence and timing of venous thromboembolism (VTE) and identify risk factors for venous thromboembolism among patients undergoing major surgery for urologic malignancies. VTE events are stratified by occurrence in the inpatient vs outpatient settings.
MATERIALS AND METHODS: The National Surgical Quality Improvement Program database was queried using Current Procedural Terminology and International Statistical Classification of Diseases, Ninth Revision codes to identify patients undergoing major surgery for urologic malignancies between 2005 and 2012. The incidence of overall 30-day VTE, postdischarge VTE, and post-VTE death was calculated for each surgical procedure. Logistic regression analysis was used to identify risk factors for VTE, adjusting for covariates including age, race, gender, smoking status, medical comorbidities, performance of pelvic lymph node dissection, and operative time.
RESULTS: The study identified 27,455 patients who underwent an operation for malignancy--radical nephrectomy, partial nephrectomy, nephroureterectomy, radical prostatectomy, or radical cystectomy. The incidence and timing of VTE varied substantially across the procedures of interest. Overall, VTE occurred after radical cystectomy in 113 of 2065 of patients (5.5%), whereas only 19 of 2624 (0.7%) and 12 of 1690, respectively, of patients undergoing minimally invasive radical or partial nephrectomy procedures suffered a VTE event within 30-days of surgery. Among patients suffering a VTE after radical prostatectomy, 147 of 178 of venous thromboembolic events (82.6%) occurred after hospital discharge.
CONCLUSION: This study demonstrates the significant burden of VTE beyond the time of hospital discharge. Identification of high-risk patients should prompt consideration of extended-duration VTE prophylaxis in the outpatient setting.