Unfractionated Heparin Administered Every 8 h Outperforms 12 Hourly Administration for Venous Thromboembolism Prophylaxis in Reconstructive Head and Neck Tumor Patients: A 12 Year Retrospective Cohort Study

ABSTRACT Background Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), poses a significant risk of morbidity and mortality in surgical patients, especially those undergoing head and neck cancer surgery with microvascular free flap reconstruction. These patients are at a heightened risk of VTE due to numerous patient and surgical risk factors. VTE chemoprophylaxis guidelines in these patients are limited due to a distinct paucity of research. This study aims to contribute to this scarcity of information, providing guidance for surgeons. Methods This retrospective cohort study evaluated the efficacy and safety of subcutaneous unfractionated heparin administered every 8 h versus every 12 h for postoperative VTE prophylaxis in patients undergoing head and neck resections with immediate free flap reconstruction. Data was collected from hospital medical records between January 2010 to December 2021. Patient demographics, operative details, and outcomes, including incidence of VTE and bleeding complications, were analyzed. Results Among 622 patients, those receiving heparin every 8 h (n = 393) demonstrated a significantly lower rate of VTE (0.8%) compared to 12‐hourly group (n = 229; 3.9%) (p = 0.006). Additionally, there were no significant differences in the rates of postoperative hematoma between the two groups (9.4% versus 7.9% respectively, p = 0.510). Conclusion Our study suggests that an increased daily dose of unfractionated heparin every 8 h for VTE chemoprophylaxis is superior to a 12‐hourly regimen with comparable bleeding profiles. Further multicentre, prospective studies are needed to validate these results and compare the efficacy and safety of unfractionated heparin with other agents such as low‐molecular‐weight heparin in this patient group.