Clinical Outcomes of Extended Venous Thromboembolism Prophylaxis, After Oncologic Colorectal Surgery.

Introduction: Current guidelines recommend extended venous thromboembolism (VTE) prophylaxis after colorectal surgery for cancer, but adherence to these guidelines has been low. Moreover, its effectiveness has not been evaluated using real-world data.

Methods: We retrospectively analyzed a random 25% sample of the 2009-2022 IQVIA Pharmetrics® Plus for Academics (IPPA) database, an administrative claims database representative of the commercially insured population of the United States. We selected cancer patients undergoing oncologic colorectal surgery. The primary outcomes were 90-day post-discharge VTE and bleeding events. The association of preoperative and intraoperative variables with the outcomes was assessed using univariate and multivariable main effects logistic regression models.

Results: A total of 13,117 surgeries were analyzed (35.0% laparoscopic colectomy, 33.4% open colectomy, 17.3% laparoscopic rectal resection, and 14.2% open rectal resection). The median age was 59 years and 52% were female. Extended VTE prophylaxis prescriptions were filled for 676 patients (5.2% of eligible patients), primarily with enoxaparin (95.5%), and increased over time (1.7% in 2010 to 12.0% in 2021). After risk adjustment, extended VTE prophylaxis was not associated with 90-day post-discharge VTE (OR 1.15; 95% Confidence Intervals 0.68-1.83) or bleeding [OR 0.93; 95% CI (0.63-1.33)]. The only factors independently associated with post-discharge VTE were the Elixhauser comorbidity score and surgery type.

Discussion/conclusion: Most patients undergoing colorectal surgery for cancer did not receive extended VTE prophylaxis. This did not appear to affect their risk of postoperative VTE or bleeding. Further research should focus on the patients most likely to benefit from extended VTE prophylaxis.