Inhibitors in hemophilia: association with surgery plans and outcomes in a retrospective cohort study.

Background: The development of antibodies (inhibitors) to clotting factors compromises the management of hemophilia A and B, resulting in resistance to clotting factor replacement and, in many cases, the need for bypassing agents to achieve hemostasis. Objectives: To evaluate the association between the presence of inhibitors and achievement of perioperative hemostasis, development of complications, and presurgical plan deviations. Methods: We conducted a retrospective study using data from the Indiana Hemophilia and Thrombosis Center surgical database (1998-2019). Associations between perioperative outcomes and inhibitor status were assessed while controlling for patient and procedural characteristics. Results: A total of 1492 surgeries were performed in 539 persons with hemophilia, with 72 procedures performed in 20 patients with inhibitors (15 with hemophilia A; 5 with hemophilia B). High-responding inhibitors (>5 BU/mL) were present in 27 procedures, low-responding inhibitors (≤5 BU/mL) were present in in 13 procedures, and 32 procedures were performed in patients with historically persistent inhibitors. Adjusting for age, diagnosis, surgery setting, hemostatic agent, data collection period, and surgery type (major/minor), inhibitors were associated with a higher risk of inadequate perioperative hemostasis (33.4% vs 8.6%; adjusted relative risk [adjRR], 3.78; 95% CI, 1.89-7.56; Conclusion: Inhibitors are associated with higher risks of adverse perioperative outcomes. Strategies to address inhibitor development should be prioritized to avoid undesirable perioperative outcomes.