Background: A common complication following total knee arthroplasty (TKA) is the formation of blood clots (venous thromboembolism or VTE). Clotting begins in the leg and can travel to the lungs, leading to respiratory distress and even death. Rivaroxaban is a common blood thinner used to prevent postoperative VTE. Despite this practice, some patients still develop VTE, with clinical features seemingly preceding rivaroxaban administration. As rivaroxaban can only prevent new clots from forming after administration, clot formation may be attributed to factors during the urgery, before the drug is given.
Objective: The aim of this study was to evaluate the intraoperative factors that were associated with VTE following TKA despite rivaroxaban administration.
Methods: We conducted a retrospective case-control study in Hamilton (2013-2015). Patients who received rivaroxaban but developed VTE within 14 days of TKA were identified. Each index patient was matched to two controls who were receiving rivaroxaban but had no VTE complication. Patients’ demographics and medical histories and the duration of tourniquet application were extracted.
Results: Seven postoperative VTEs were identified from a total of 234 patients. During the surgery, the index cases had a significantly longer tourniquet application time than the controls (65±3.3 min and 49±2.4 min, respectively). There were no intraoperative complications and no noticeable differences in blood loss.
Conclusion: This study illustrates that intraoperative factors such as prolonged tourniquet application are associated with postoperative VTE, explaining the failure of rivaroxaban. We suggest a reduction in tourniquet application time as well as more emphasis on pre-surgical anticoagulation treatment.
By Owais Mian