Hematologic Complications After Epiphysiodesis for Vascular Malformation-Related Leg-Length Discrepancy: A Retrospective Cohort Study

Objective: Vascular anomalies are classified into vascular tumors and vascular malformations (VaMs). When located in the lower extremity, VaMs may lead to leg-length discrepancy (LLD), for which permanent epiphysiodesis is a common surgical correction. However, inherent risks of bleeding and venous thromboembolism (VTE) in this patient population raise perioperative concerns. We explored the prevalence and risk factors of these complications among VaM-related LLD patients undergoing permanent epiphysiodesis. Methods: We conducted a retrospective study of VaM-related LLD patients who underwent permanent epiphysiodesis at Boston Children’s Hospital from 1998 to 2022. Primary outcomes were VTE, including deep vein thrombosis, pulmonary embolism (PE), and bleeding events occurring within 30 days of surgery. Malformation subtype, coagulation abnormalities, prophylactic anticoagulation, and additional factors were examined via multivariable logistic regression. Results: Ninety patients were included. The 30-day postprocedure VTE incidence was 3.3% (n = 3; 95% confidence intervals: −8.5–0.4), all deep vein thrombosis within the slow-flow group, with no PEs detected. Clinically significant bleeding occurred in 12.2% (n = 11; 95% confidence intervals: −11.0–28.0), with no difference by VaM flow type. Late events included 1 PE (1.1%) and 2 deaths (2.2%), none attributed to the procedure. After applying the Bonferroni adjustment, none of the risk factors studied reached statistical significance in univariate or multivariate analyses. Conclusion: Our findings indicate that while inherent factors related to VaM may increase the risk of thrombosis and bleeding, the incidence is low with procedures like epiphysiodesis. Periprocedural assessment is recommended in high-risk patients. Additional studies are needed to clarify risk factors and improve preventive strategies.