Evaluating the role of preoperative anticoagulation in reducing the risk of venous thromboembolism in orthognathic surgery: a review of the literature and local audit.

Orthognathic surgery is commonly performed in healthy young adults and is associated with a low baseline risk of venous thromboembolism (VTE). However, considerable variation exists in the United Kingdom regarding the routine administration of preoperative pharmacological thromboprophylaxis with low molecular weight heparin (LMWH). The aim of this article is to review the current evidence for preoperative LMWH in orthognathic surgery, focusing on the incidence of VTE and the potential risk of perioperative bleeding, and to report findings of a local audit. Published literature demonstrates that symptomatic VTE following orthognathic surgery is rare, with reported incidences below 0.2% even in centres not using routine chemoprophylaxis. In contrast, anticoagulation has been linked with increased rates of postoperative bleeding complications, including haemorrhage requiring return to theatre, which raises concerns that routine prophylaxis may confer more harm than benefit in low-risk patients. A retrospective audit of 313 patients undergoing orthognathic surgery at a tertiary UK unit between January 2022 and February 2025, all of whom received prophylactic preoperative LMWH, identified no VTE events within three months of the operation. Intraoperative bleeding complications occurred in 12 patients (3.8%). Overall, current evidence does not support routine preoperative LMWH in low-risk orthognathic patients. Risk-stratified approaches are recommended, and prospective multicentre studies are needed to establish clear guidelines.