Rivaroxaban vs LMWH after elective foot and ankle surgery – audit and experience from a tertiary referral centre

T.M. Mamballi, I. Hassan, S. Patel, N. Cullen, M. Welck, K. Malhotra

Background: In the UK, NICE recommends injectable low-molecular weight heparin (LMWH) for chemical prophylaxis of venous thromboembolism (VTE) after elective foot and ankle surgery (NG89-2018). However, due to challenges surrounding administration, monitoring and compliance, our trust switched to oral anti-coagulants (Rivaroxaban) in 2022. The aim of this audit was to compare Rivaroxaban and LMWH, looking at VTE rate and complication profile.

Methods: This was a retrospective audit at a single, tertiary centre. Adult patients undergoing elective foot and ankle surgery and treated with chemical anticoagulation were included. We compared patients treated with Tinzaparin (6-month period in 2019) and Rivaroxaban (6-month period in 2022). Patients on pre-existing alternative anti-coagulants were excluded. At our centre complications data is collected prospectively, and a review of this database and clinic notes was conducted. A chi-squared test was used to assess significance of differences.

Results: In the Tinzaparin group there were 110 patients and 20 had minor complications (18.2%): 4 superficial wound infections (3.6%), and 16 patients required excessive dressing changes due to persistent exudate or slower healing (14.5%). There were no haematomas, returns to theatre, or VTE. In the Rivaroxaban group there were 107 patients and 23 had complications (21.5%): 1 superficial wound infection (0.9%), 1 case of post-operative bleeding followed by haematoma (0.9%), 19 cases with increased dressing changes (17.8%), and one case of VTE two weeks after completing treatment (deep vein thrombosis, 0.9%). None of these differences were statistically significant. Amongst those with wound complications, there were more cases performed for revision / infection in the Rivaroxaban group.

Conclusion: Overall, Rivaroxaban appears effective and safe, with a comparable complication profile to LMWH. The small differences between groups may be explained by differences in the sampled cohorts. Larger scale studies are required to determine whether observed differences are truly non-significant.