[Thromboembolism of the pulmonary artery in Willebrand's disease]

To ascertain risk factors of thromboembolism of the pulmonary artery (TPA) in Willebrand's disease (WD).

We made a retrospective analysis of hospitalizations of WD patients for 10 years. We analysed causes of the patients' admission, interventions, registered maximal levels of factor VIII (FVIII) and Willebrand's factor (FW) in which the interventions were made, cases of TPA.

Thirty four patients with WD were hospitalized 45 times. Three patients were treated conservatively because of gastrointestinal bleeding, the rest patients received surgical therapy. All the patients were given FVIII concentrates, cryoprecipitate, fresh-frozen plasma. In the course of the treatment, FW and FVIII levels were determined in 38% cases, FW--in 23%, FVIII--in 27%, coagulation was studied in 12% without test for FVIII and FW levels. Maximal concentration of FW was 72.1 +/- 11.8%, FVIII--125 +/- 15.8%. TPA developed in 2 (4.4%) of 45 patients. In both cases we observed a marked rise of plasmic concentration of FVIII due to therapy (250 and 240%).

In patients with WD thromboembolic complications risk factors are age, obesity, surgical interventions, immobilization, etc. Simultaneous administration of several drugs containing FW and FVIII was also among the risk factors. Overdosage of FVIII is one of the causes of thrombotic complications in WD. FW and FVIII correlations in FVIII preparations must be considered. Prophylactic heparin therapy is recommended in patients with a high risk of thrombotic complications upon achievement of normal hemostasis.