Venothromboembolism and radical cystectomy: Prevalence of risk factors and comparison of anticoagulation use.

Abstract

339 Background: Radical cystectomy is a major pelvic surgery associated with relatively high rates of venothromboembolism (VTE). This study focuses on prevalence of known risk factors in patients undergoing radical cystectomy who suffered a symptomatic VTE and compared use of warfarin and heparin in prophylaxis. Methods: We conducted a retrospective review of 2,730 patients who underwent open cystectomy at USC between 1971-2012 using the IRB approved bladder cancer database. Patients who suffered VTE during the peri-operative period were identified. Preoperative, operative, and postoperative risk factors for VTE were analyzed. Data on use of anticoagulation was obtained and used to compare a historical cohort of warfarin use as prophylaxis (1971-2007) to the modern cohort of subcutaneous heparin use (2009-2012). A Chi-squared test was used to determine significance of any differences in prophylaxis use. Results: A total of 129 patients (4.7%) with symptomatic VTE were identified. 112/129 (86.8%) fit intent to cure inclusion criteria and were further evaluated for demographic information (85% male, median age 69.9, median BMI 27.9, and smoking history in 61.6%) and risk factors. Of pre-operative VTE risk factors, previous chemotherapy (9.8%) and other active medical illness (17.4%, e.g. atrial fibrillation, hypothyroidism, congestive heart failure) were most common. Median operative time was 363 minutes; median EBL was 800 ml with median transfusion of 2.0 units of PRBCs. The median day of first ambulation was POD 3, median LOS was 11 days, and a median interval between surgery and VTE diagnosis was 20.5 days. 15.1% of VTE patients also had a post-op infection. Of the 129 VTE cases, the overall rate from 1971-2007 (treated with warfarin) was 4.1%, while the rate from 2009-2012 (treated with heparin) was 6.3% (p=0.054). Percent of patients with a VTE occurring after discharge from 1971-2007 and 2009-2012 were 2.3% and 4.1%, respectively (p=0.052). Conclusions: Most VTEs occur after discharge, indicating a possible need for VTE prophylaxis beyond the immediate post-op period. There was a trend toward reduced risk of VTE with post-operative use of warfarin compared to heparin.