Risks and Benefits of Caprini Score Recommended Thromboprophylaxis After Radical Prostatectomy and Nephrectomy

Venous thromboembolism (VTE) after urologic surgery occurs in about 1% of patients and is associated with peri-operative morbidity and mortality. Given variability in thromboprophylaxis practice, we aim to analyze the utilization of Caprini risk-based thromboprophylaxis after prostatectomy and nephrectomy. Cases were identified using the medical record from large tertiary care centers in the United States. Caprini score was calculated retrospectively. Prophylaxis was classified as either appropriate or inappropriate when comparing Caprini score recommendations to prophylaxis received. Bleeding was determined by ICD-10 diagnostic code, post-operative hemoglobin decrease of >4 g/dL, or transfusion. Bivariate and multivariate regression analyses compared VTE and bleeding outcomes between prophylaxis cohorts. In the 6,241 patients analyzed, inpatient, post-operative VTE rate was 0.72%. Appropriate inpatient prophylaxis was received by 36% of prostatectomy patients and 50% of nephrectomy patients. Less than 5% of patients in both cohorts received recommended appropriate discharge prophylaxis. Appropriate inpatient prophylaxis after prostatectomy resulted in an 8-fold significant reduction in inpatient VTE (0.07% vs. 0.61%, p=0.009) with an associated increased bleeding incidence (2.3% vs. 0.98%, p<0.001). The incidence of inpatient VTE after radical nephrectomy was 5.8-fold higher (1.7% vs. 0.29%, p=0.001) with inappropriate prophylaxis without a significant increased risk of bleeding. There was no significant difference in VTE rates or bleeding at 90 days post-operatively when stratifying by discharge prophylaxis in either cohort. For those identified as high risk by Caprini Score, the benefits of inpatient VTE chemoprophylaxis must be balanced with bleeding risk after prostatectomy and nephrectomy.