Evaluation of Thrombotic Events in Haemophiliacs Undergoing Major Orthopaedic Surgery without Thrombosis Prophylaxis.

Introduction:Major orthopaedic procedures and the presence of thrombophilia are risk factors of thrombotic events. In patients with haemophilia undergoing hip or knee replacement the importance of thrombosis prophylaxis with heparin in the postoperative period is still unknown. The aim of the present study was to evaluate the occurence of thrombotic events in haemophiliacs undergoing major surgery without thrombosis prophylaxis.

Patients: A total of 32 pts with haemophilia A (severe:27 pts, moderate:4 pts, mild:1pt; median age:47yrs, range:27–73yrs) undergoing hip (n=9)or knee (n=35) replacement were analysed in our haemophilia treatment center. Pts with inhibitors were excluded. Surgical interventions were performed using recombinant (n=37) or plasma-derived (n=7) FVIII for 12 to 15 postoperative days. The median initial dose of FVIII was 82 IU/Kg⁻¹, followed by median FVIII doses of 54 IU/kg⁻¹over the first four days. All pts received thrombosis prophylaxis with graduated compression stockings only. In addition to factor VIII activity, APC resistance, FV G1691A mutation and the FII G20210A variant (FII) were investigated.

Results: No thrombotic events in the postoperative period was dokumented. The median FVIII activity was 153% (range:85–347%), the Body mass index (BMI:kg/m²) was 23.1(range:18.2–30.5). During the first four postoperative days FVIII levels >150% were measured in 24/44 (55%) operative procedures. BMI>25 were shown in 12/32 (38%) pts, and age >40yrs was documented in 23/32 (72%) pts. In 1/30 (3%) pt APC resistance and none of our pts FII were identified.

Conclusion: In our study group elevated FVIII levels and additional risk factors (BMI>25, age>40years) seems not to influence relevantly the occurrence of thrombotic events in pts with haemophilia undergoing hip or knee replacement without thrombosis prophylaxis. Further studies are required to confirm whether a thrombosis prophylaxis with heparin is needed in haemophiliacs undergoing high risk surgery.