Efficacy of thromboprophylaxis following stage II surgical palliation for single-ventricle physiology: A systematic review and meta-analysis.

Background: Postoperative thrombosis remains a significant cause of mortality and morbidity, especially in patients with single-ventricle physiology (SVP). The standard management plan for SVP consists of a three-stage surgical palliation, with widely varying thromboprophylaxis strategies. While routine thromboprophylaxis is standard after stages I and III, its role for stage II palliation remains controversial. This study aims to evaluate the impact of routine thromboprophylaxis in patients undergoing stage II palliation, with particular attention to cases involving pulmonary artery (PA) reconstruction, where the risk-to-benefit ratio of therapy may differ from routine stage II procedures.

Methods and results: Analyses were conducted across 15 studies published between 1981 and 2021 (n = 1682), assessing the impact of routine thromboprophylaxis on thromboembolic events, mortality, and major adverse events (MAEs). A significant potential benefit of thromboprophylaxis use was observed only in the subgroup of patients undergoing PA reconstruction (14% in the thromboprophylaxis group versus 6% in the no-thromboprophylaxis group; P = 0.01). The prevalence of thromboembolic events in the overall population was 5% (95% confidence interval [CI]: 3%-8%) without a significant difference between the two groups (P = 0.88). The pooled odds ratio (OR) showed a nonsignificant effect of thromboprophylaxis in reducing thrombotic events (OR = 0.35, 95% CI: 0.02-7.81). No significant differences were observed in thromboembolic events, MAEs, and mortality rates between the groups receiving thromboprophylaxis or no thromboprophylaxis (P = 0.88, 0.29, 0.45, respectively).

Conclusions: This study supports the use of routine thromboprophylaxis following second-stage palliation of SVP, particularly in patients undergoing PA reconstruction. However, the evidence is limited by observational study designs, heterogeneity among studies, and the lack of recent high-quality data. Further well-designed studies are warranted to confirm these findings and to identify the optimal antithrombotic agent.