The Role of Anticoagulation Regimen on Flap Outcome in Microvascular Head and Neck Reconstruction

J Oral Maxillofac Surg. 2024 Dec 31:S0278-2391(24)01027-9. doi: 10.1016/j.joms.2024.12.011. Online ahead of print.

Abstract

Background: Thrombus formation following flap reconstruction reduces perfusion and can lead to flap compromise. Effective anticoagulation protocols are essential to prevent this complication.

Purpose: The study's purpose was to measure and compare flap compromise associated with 3 different anticoagulation protocols.

Study design, setting, sample: This retrospective cohort study included patients with head and neck cancer who underwent flap reconstruction. Exclusion criteria included patients who did not consent to participate, did not receive the anticoagulation regimen, or had a history of adverse reactions to heparin or aspirin (ASA).

Exposure: The primary exposure was the anticoagulation protocol, which was divided into 3 groups: intravenous unfractionated heparin (IV-UFH), subcutaneous UFH (SC-UFH), and SC-UFH plus ASA.

Main outcome variable: The outcome variable was postoperative flap outcome coded as compromised or not.

Covariates: Covariates included patient demographics, cancer type, neoadjuvant therapy, flap type, surgical procedure, intensive care unit stay, medical history, and postoperative complications.

Analyses: χ2, Mann-Whitney U, and Kruskal-Wallis tests were used for baseline data analysis. Multivariate logistic regression was conducted to examine the adjusted association between anticoagulation protocol and flap outcome. P values < .05 were considered statistically significant.

Results: The study sample consisted of 300 patients who met inclusion criteria with a mean age of 48.3 (±17.69) years, 202 (67.3%) of whom were male. There were 28 (9.3%) cases of flap compromise. The unadjusted analysis showed that patients receiving IV-UFH had a significantly higher risk of flap compromise compared to those receiving SC-UFH (relative risk: 3.43 [1.62 to 7.28]). Adding ASA to SC-UFH did not result in a statistically significant reduction in the risk of flap compromise (relative risk: 0.95 [0.35 to 2.61]). After adjusting for confounding factors, the anticoagulant type was not associated with flap compromise (P = .05). However, in the subgroup analysis, compared to SC-UFH, subjects receiving IV-UFH still had higher odds of flap compromise (odds ratio = 2.69, 95% CI [1.003 to 7.205], P = .049) CONCLUSION AND RELEVANCE: Postoperative thrombosis in head and neck microsurgery remains a significant risk factor for poor outcomes. SC-UFH administration may be a practical approach to managing these risks compared to intravenous administration; however, the choice of anticoagulation protocol is not associated with the flap compromise.