Efficacy of pre-operative pharmacologic thromboprophylaxis on incidence of venous thromboembolism following major gynecologic and gynecologic oncology surgery: a systematic review and meta-analysis.

Introduction: Venous thromboembolism remains a significant complication following major gynecologic surgery. Evidence is lacking on whether it is beneficial to give pharmacologic thromboprophylaxis pre-operatively. The aim of this meta-analysis was to assess the role of pre-operative pharmacologic thromboprophylaxis in preventing post-operative venous thromboembolism.

Methods: PubMed, EMBASE, and the Cochrane Central Register of Clinical Trials were searched to find randomized controlled, cohort, and case-control trials comparing pre-operative pharmacologic thromboprophylaxis to no prophylaxis, mechanical prophylaxis, or only post-operative pharmacologic thromboprophylaxis for open and minimally invasive major gynecologic surgery (benign and malignant conditions). Two authors independently assessed abstracts, full-text articles, and methodological quality. Data were extracted and pooled using ORs for random effects meta-analysis. Heterogeneity was explored using forest plots, Q-statistic, and I statistics. Planned subgroup analysis of use of sequential compression devices, equivalent versus non-equivalent post-operative prophylaxis, cancer diagnosis, and methodological quality were performed.

Results: Some 503 unique studies were found, and 16 studies (28 806 patients) were included in the systematic review. Twelve studies (14 273 patients) were included in the meta-analysis. The OR for incidence of post-operative venous thromboembolism was 0.59 (95% CI 0.39, 0.89), favoring pre-operative pharmacologic thromboembolism prophylaxis compared with no pre-operative pharmacologic prophylaxis (Q=13.80, I=20.30). In studies where post-operative care was equivalent between groups, the OR for venous thromboembolism was 0.56 (95% CI 0.22, 1.40). Pre-operative pharmacologic prophylaxis demonstrated greatest benefit when utilized with both intra-operative and post-operative sequential compression devices (OR 0.43, 95% CI 0.30, 0.64) compared with when no sequential compression devices were utilized (OR 1.27, 95% CI 0.63, 2.56). When looking at only studies determined to be of high quality, the results no longer reached significance (OR 0.73, 95% CI 0.36, 1.46).

Conclusions: Pre-operative pharmacologic thromboprophylaxis decreases the odds of venous thromboembolism in the peri-operative period for major gynecologic oncology surgery by approximately 40%. It remains unclear whether this benefit is present in benign and minor procedures. Adequately powered studies are needed.