Multicentric Study Evaluating Venous Thrombosis Among Patients with Haemophilia Undergoing Major Orthopaedic Surgery

Deep venous thrombosis (DVT) is a common postoperative complication in patients undergoing major orthopaedic surgery of the lower limbs, such as total hip replacement (THR), total knee replacement (TKR), or hip fracture surgery (HFS). In the absence of thromboprophylaxis, subclinical venous thrombosis rates as high as 60% have been reported when using systematic bilateral phlebography after orthopaedic surgery. As a result, routine pharmacological thromboprophylaxis with low-molecular-weight heparin (LMWH) or a new oral anticoagulant agent is strongly recommended in patients undergoing these procedures.

With the availability of efficient and safe clotting factor concentrates, THR, TKR, as well as ankle arthrodesis are frequently performed in subjects with haemophilia suffering from chronic haemophilic arthropathy. Yet, pharmacological prophylaxis of venous thromboembolism (VTE) in this patient group remains controversial. With the exception of retrospective case reports and small series, the incidence of VTE disease in haemophilic patients after major orthopaedic surgery is still unclear. Surveys suggest that more than half of hemophilia treatment centers in the United States and Europe use thromboprophylaxis in patients with haemophilia (PWH) who require major orthopedic surgery. However, this is not supported by evidence or surgical practice guidelines, and simply increases the risk of bleeding in such patients. Given the aging nature of the haemophilia population and the incidence of joint disease, the question of the thrombotic risk associated with major orthopaedic surgery and joint replacement surgery in particular is highly relevant. Few studies have addressed this issue and more information is needed on which to base optimal preventive strategies for venous thrombosis in patients with haemophilia undergoing elective major orthopedic surgery.

We here report the results of 2 parallel and independent prospective studies from Belgium and Norway currently evaluating by systematic US-Doppler imaging the incidence of subclinical deep venous thrombosis in consecutive haemophilic patients referred for major orthopaedic surgery. In Belgium, the study has so far included 36 different patients (32 HA, 4HB) undergoing 50 major orthopaedic procedures of the lower limbs. In Norway, the study has involved 29 patients (26 HA, 3 HB, all with severe haemophilia) undergoing 29 orthopaedic procedures, most of the lower limbs. In both countries, most patients were treated with continuous infusion of clotting factor concentrates and none of them did receive antithrombotic pharmacological prophylaxis.

In the 2 studies that included in total 65 patients undergoing 79 major orthopaedic procedures, no case of clinically patent DVT or PE was detected (Table 1). In total there were 5 cases of DVT evidenced by US imaging which were all distal, not complicated by PE and treated with a short course of low-molecular weight heparin in most cases. The overall incidence of subclinical DVT calculated on the whole population was 6%.

In conclusion, these data provide for the first time multicentric and imaging-based evidence that the risk of DVT following major orthopaedic surgery among patients with haemophilia undergoing major orthopaedic surgery is very low and that systematic pharmacological thromboprophylaxis in this specific population is for most patients not required. The two studies are still ongoing and should include a larger number of participants in the future.