Tranexamic acid is safe with respect to the risk of deep venous thrombosis in patients with hemophilic arthritis undergoing total knee arthroplasty without chemoprophylaxis: A prospective study

BACKGROUND

Pharmacologic thromboprophylaxis is controversial for hemophiliacs who undergo total joint replacements. The purpose of this study was to assess the safety of tranexamic acid (TXA) utilization with respect to the incidence of deep venous thrombosis (DVT) in hemophiliacs undergoing total knee arthroplasty (TKA).

METHODS

A total of 104 patients with hemophilic arthritis were included in the study. The patients were randomly divided into two groups of 52 subjects. All patients received a modified coagulation factor substitution regimen. In the TXA group, 1 g of TXA was injected intravenously 15 min before incision and 2 g of TXA was intra-articularly injected in the surgical area. A routine mechanical prophylaxis was administered to all patients under a standardized postoperative protocol. Thromboembolic complications in both groups were followed up for 2 years.

RESULTS

All patients were male and underwent 146 arthroplasties. There was a mean age of 33.2 ± 8.8 years and a mean body mass index of 22.2 ± 5.1 kg/m2. A 100% compliance rate was observed with mechanical prophylaxis. No asymptomatic DVT was detected on postoperative ultrasound in all patients. We also failed to find any proof of clinical venous thromboembolism in our patients during a 2-year follow up. Only two cases in the TXA group underwent blood transfusions (4.0%), while 29.2% of the patients in the non-TXA group needed transfusion.

CONCLUSIONS

This prospective study showed that TXA could be safely utilized in patients with hemophilic arthritis who underwent TKA without increasing the incidence of DVT and routine chemoprophylaxis may not be necessary.

Incidence of Symptomatic Venous Thromboembolism in Patients with Hemophilia Undergoing Hip and Knee Joint Replacement without Chemoprophylaxis: A Retrospective Study

OBJECTIVE

To establish the prevalence of clinically significant venous thromboembolic events (VTE) in hemophilia patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) without chemoprophylaxis and a modified coagulation factor substitution.

METHODS

A cohort of patients who underwent THA and TKA from June 2002 to April 2017 were included. Based on World Federation of Hemophilia (WFH) guidelines, a modified coagulation factor substitution regimen was adopted. All patients were under a standardized postoperative protocol with routine mechanical prophylaxis against VTE. None of the patients received prophylactic anticoagulation. Only symptomatic patients were referred for radiological examination to exclude VTE. We evaluated the patient demographics and calculated the prevalence of VTE in our cohort.

RESULTS

A total of 98 patients were reviewed. The patients were all men. Thirty-one patients underwent primary THA with 39 hip arthroplasties (only 1 case with hemophilia B) and 67 patients underwent primary TKA with 101 knee arthroplasties (5 cases with hemophilia B). The mean age was 34.2 ± 7.8 years. The mean body mass index was 21.2 ± 5.7 kg/m² . There was 100% compliance to mechanical prophylaxis. The mean time to ambulation was 6.8 days (±2.5 days), and the mean hospital stay was 32.4 days (±7.1 days). There was only 1 hemophilia B patient with clinically significant VTE. None of the other 97 surgical cases had symptomatic VTE within 6 months after the procedure. This translates to a prevalence of 1.02%.

CONCLUSION

Given the low incidence (1.02%) of clinically significant VTE in our cohort, routine chemoprophylaxis in hemophilia patients undergoing THA and TKA may not be needed.

Joint WFH-ISTH session: issues in clinical trial design

Haemophilia therapy is experiencing an unprecedented expansion in the number and novelty of clotting factor concentrates. Every product must be licensed by regulatory authorities, primarily on the basis of its safety and efficacy profiles. The low prevalence of haemophilia, and other inherited bleeding disorders, presents a significant challenge to patient recruitment for preauthorization clinical trials, especially given the low frequency of inhibitory antibodies, the major adverse event related to clotting factor exposure. Other challenges include a lack of harmonization between the major regulatory authorities in certain key areas, the selection of laboratory monitoring methodologies and the difficulty in obtaining high-quality phase IV safety data following authorization. These aspects will be reviewed in this session, which will also highlight the roles played by the World Federation of Hemophilia and International Society on Thrombosis and Haemostasis in the promotion of these discussions.