[Recurring thrombosis of the subclavian vein during estrogen therapy of prostatic cancer].

A cardiac pacemaker had been implanted in a patient with carcinoma of the prostate because of a sick sinus node. Thrombosis of the left subclavian vein occurred four weeks later. After complete recanalisation following thrombolytic treatment a recurrence of the thrombosis occurred during high-dosage intravenous oestrogen treatment. Continuous increase of prothrombin time was observed during oestrogen administration while the oral anticoagulation had remained unaltered. This indicated increase of synthesis of vitamin-K-dependent clotting factors by the oestrogens. This case demonstrates that in patients with implanted material and oral long-term anticoagulation the indication for oestrogen treatment must be extremely accurately. In every case very close surveillance of coagulation is necessary.