THROMBUS FORMATION ON TRANSCATHETER ASD OCCLUDER DEVICE IN A PATIENT WITH COAGULATION-FACTOR-XII DEFICIENCY

Transcatheter occlusion of cardiac defects has become an effective and less invasive alternative to open heart surgery. Thromboembolic compl ications are rare events, after both surgical and transcatheter closur e of atrial septal defects [Galal et al.: Eur Heart J 15:1381-1384, 19 94]. We report on a case of thrombus formation on the atrial septal de fect occluder system (ASDOS) [Sievert et al.: Cathet Cardiovasc Diagn 36:232-240, 1995; Hausdorf et al.: Heart 75:83-88, 1996]. Two days aft er transcatheter occlusion, the patient suffered an acute stroke due t o embolism despite anticoagulation with intravenous heparin. A coagula tion disorder with reduced factor XII concentration was deduced as the likely cause. Repeated transesophageal echocardiographic (TEE) studie s revealed an involution of the intracardial thrombus within weeks of subsequent anticoagulatory treatment. Firstoff, this case shows that p atients with factor XII deficiency are at risk for thromboembolism. Se cond, it again clarifies that even large amounts of intraarterial thro mbotic material may not be seen by transthoracic echocardiography (TTE ) and underscores the necessity of performing TEE. Screening patients for coagulation disorders (Quick's value (Q), partial thromboplastin t ime (PTT)) before they are selected for treatment with thrombogenic de vices is indispensable, With regard to their personal history (earlier thromboembolism) and the result of this screening (e.g., prolongation of PTT), quantitative determination of coagulation factors is reasona ble. If patients endangered by thromboembolic complications neverthele ss undergo ASD occlusion procedures, anticoagulation monitoring requir es exceptional attention. Furthermore, it is recommended that TEE shou ld be carried out in these patients 2 days after treatment, since tran sthoracic echocardiography (TTE) might be unable to detect thrombus fo rmation on the device. (C) 1998 Wiley-Liss, Inc.