Chemoprophylaxis for VTE following Head and Neck Surgery

Does venous thromboembolism prophylaxis reduce the incidence of venous thromboembolism after head and neck surgery?

Background: Venous thromboembolism (VTE) is a common complication in surgical patients and a significant cause of morbidity and mortality. Prophylaxis guidelines for otolaryngology patients have been extrapolated from guidelines for other surgical populations and include subcutaneous unfractionated heparin or low molecular weight heparin. Because many head and neck surgery patients undergo free flap reconstruction and receive anticoagulation or antiplatelet therapy, the safety and effectiveness of VTE prophylaxis in this specific population has been understudied.

Study design: Retrospective chart review of adult patients hospitalized after otolaryngologic surgery between 2003 and 2010. Caprini risk score—a measure of VTE risk, VTE and bleeding outcomes—within 30 days of surgery were evaluated. VTE was confirmed by venous duplex ultrasound, CT scan, ventilation-perfusion scan, or post-mortem.

Setting: University of Michigan.

Synopsis: There were 3,498 patients who met study criteria, with VTE prophylaxis administered to 1,482 patients. Microvascular reconstruction was performed in 522 (15%). The incidence of VTE was 1.2% in patients who received VTE prophylaxis and 1.3% in patients who did not (P=0.75). Patients with a higher Caprini risk score were more likely to receive VTE prophylaxis and were more likely to also be treated with sequential compression devices. When stratified by Caprini risk score, VTE prophylaxis was more effective in patients with a score higher than 8, in whom the incidence of VTE was 18.3% without prophylaxis and 10.7% with prophylaxis. Patients undergoing microvascular reconstruction had a higher incidence of VTE without prophylaxis (7.6%) compared with all other patients (0.6%), which remained elevated after stratifying by Caprini score. VTE prophylaxis was associated with a reduced incidence of VTE after microvascular reconstruction (2.1%). Bleeding complications were higher in microvascular reconstruction patients who received VTE prophylaxis (11.9%) compared with those who did not (4.5%, P=0.01). In patients receiving VTE prophylaxis, intraoperative antiplatelet drugs (ketorolac and aspirin) were associated with a significantly increased risk of bleeding complications on multivariate analysis.

Bottom line: The efficacy of VTE chemoprophylaxis is greatest in patients with a Caprini risk score higher than eight; however, in patients receiving intraoperative antiplatelet therapy, VTE chemoprophylaxis was associated with a significant increase in bleeding complications.

Citation: Bahl V, Shuman AG, Hu HM, et al. Chemoprophylaxis for venous thromboembolism in otolaryngology. JAMA Otolaryngol Head Neck Surg. 2014;140:999-1005

—Reviewed by Christine G. Gourin, MD