PD13-06 EFFECT OF PHARMACOLOGIC PROPHYLAXIS ON VENOUS THROMBOEMBOLISM AFTER RADICAL PROSTATECTOMY: THE PREVENTER RANDOMIZED CLINICAL TRIAL

Abstract

INTRODUCTION AND OBJECTIVE: No level‐one evidence is available evaluating perioperative pharmacologic prophylaxis (PP) after radical prostatectomy (RP) for prostate cancer to prevent venous thromboembolism (VTE) leading to significant practice variation across countries, centers, and individual surgeons. We aimed to study the impact of PP on incidence of symptomatic VTE and adverse events after RP with a secondary objective of evaluating overall VTE in a screening subcohort. METHODS: A prospective, phase 4, single‐center, randomized trial was conducted between July 2017 and November 2018 at the Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center. Adult men with prostate cancer undergoing open or robotic‐assisted laparoscopic RP were randomized to PP (subcutaneous heparin (5,000 units) <2 hours before surgery and every 8 hours postoperatively until discharge) vs. routine care alone (intermittent pneumatic compression devices, encouragement of early ambulation). The screening subcohort was offered lower extremity duplex ultrasound at 30‐days. Primary efficacy outcome was incidence of symptomatic VTE (pulmonary embolism (PE) or deep venous thrombosis (DVT)). Primary safety outcomes included incidence of symptomatic lymphocele, symptomatic hematoma, or bleeding after surgery. Secondary outcomes were overall VTE, estimated blood loss, total surgical drain output, complications, and surveillance imaging bias. RESULTS: A total of 501 patients (75.3% robotic) were randomized and 99.8% (500/501) completed follow‐up. At the second interim analysis (N=445), the symptomatic VTE rate was 2.3% (4 PE+DVT, 1 DVT) for routine care compared to 0.9% (1 PE+DVT, 1 DVT) for PP (RR 0.40 (95% CI 0.08‐2.03), p=0.268) meeting a futility threshold for early stopping. Among the screening subcohort, the overall VTE rate was 3.3% vs. 2.4% (p=0.720). Results were similar at final analysis (symptomatic VTE: 2.0% vs. 0.8%, p=0.285; overall VTE: 2.9% vs. 2.8%, p=1.00). No differences in safety or secondary outcomes were observed. All VTE events (7 symptomatic, 3 asymptomatic) occurred in patients undergoing pelvic lymph node dissection. CONCLUSIONS: PP did not significantly reduce the rate of symptomatic or overall VTE after RP. However, there was no increase in development of symptomatic lymphoceles, bleeding, or other adverse events. PP may be safely implemented when indicated for high‐risk patients (Caprini scores ≥8) or patients receiving pelvic lymph node dissection. Results may be applicable to other minimally‐invasive surgeries with low morbidity and short hospital stays.