Venous thromboembolisms affected 6.4% of patients who underwent radical cystectomy, even though all patients received heparin in the hospital as recommended by the American Urological Association, researchers reported.

“Using an in-house, heparin-based anticoagulation protocol consistent with current AUA guidelines has not decreased the rate of venous thromboembolism compared to historical warfarin use,” wrote Dr. Andrew Sun and his colleagues at the University of Southern California Institute of Urology in Los Angeles. Most episodes of VTE occurred after patients were discharged home, and “future studies are needed to establish the benefits of extended-duration [VTE] prophylaxis regimens that cover the critical posthospitalization period,” the researchers added ( J. Urology 2015;193:565-9 ).

Previous studies have reported venous thromboembolism rates of 3%-to 6% in cystectomy patients, a rate that is more than double that reported for nephrectomy or prostatectomy patients. For their study, the investigators retrospectively assessed 2,316 patients who underwent open radical cystectomy and extended pelvic lymph node dissection for urothelial bladder cancer between 1971 and 2012. Symptomatic VTE developed among 109 patients overall (4.7%), compared with 6.4% of those who received the modern, heparin-based protocol implemented in 2009 (P = .089).

Furthermore, 58% of all cases occurred after patients stopped anticoagulation therapy and were discharged home. The median time of onset was 20 days after surgery (range, 2-91 days), and VTE was significantly more common among patients with a higher body mass index, prolonged hospital stays, positive surgical margins and orthotopic diversion procedures, compared with other patients. Surgical techniques remained consistent throughout the study.

The study was retrospective, and thus “could not prove any cause and effect relationships. This underscores the need for additional prospective data in this area of research,” said the investigators. “We focused only on open radical cystectomy, and thus, findings may not be generalizable to minimally invasive modalities, on which there is even a greater paucity of data.”

Senior author Dr. Siamak Daneshmand reported financial or other relationships with Endo and Cubist. The authors reported no funding sources or other relevant conflicts of interest.