Characteristics of patients not receiving chemical thromboprophylaxis following foot and ankle surgery: Data from the multicenter, prospective UK Foot and Ankle Thrombo-Embolism Audit (UK-FATE)

Abstract

Background: Although the rate of venous thromboembolism (VTE) after foot and ankle surgery is low, multiple factors influence risk for individual patients. Furthermore, there are no clear guidelines on which patients may benefit from chemical thromboprophylaxis. Our aim was to assess patients not treated with chemical thromboprophylaxis after foot and ankle surgery, and to report on their specific patient and surgical risk factors for VTE. Methods: This was a multicenter, prospective, national audit of patients undergoing foot and ankle surgery (including Achilles tendon ruptures) from 68 participating UK centers. The study was conducted between June 1, 2022, and November 30, 2022, with a further 3-month follow-up. Following data cleansing, 3309 patients were included who did not receive postoperative thromboprophylaxis. Results: Most patients were elective cases (2589 patients, 78.24%) with ASA grade I or II (2679 patients, 80.96%), fully weightbearing postoperatively (2752 patients, 83.17%), and either without ankle splintage, or splinted in a plantigrade boot (2797 patients, 84.53%). The VTE rate was 0.30% overall (11 cases), with no VTE-related mortality. No single demographic, surgical, or postoperative factor was associated with reduced risk of VTE. However, patients who had elective or trauma surgery not involving the ankle, who were ASA grade I or II and who were weightbearing immediately postoperatively (without splinting or in a plantigrade boot) had a VTE rate of 0.05% (1 of 1819 patients), compared with 0.67% (10 of 1490 patients, P = .002). Conclusion: Patients not receiving chemical thromboprophylaxis had a low incidence of symptomatic VTE, although they do represent a curated group considered lower risk. Within this group we describe characteristics associated with a substantially lower risk of VTE. All patients should be assessed on an individual basis, and further work is required to substantiate our findings.