超音波在心律調節器併發之右心房血栓的處理所扮演之角色

Real-time Detection of Migratory Thrombi by Transesophageal Echocardiography in a Patient Undergoing Thrombectomy

一位44歲男性病人，因為第三度心房心室傳導阻塞，而放入經靜脈心律調節器。心臟超音波顯示出在右心房有一團狀物，於是計晝施行手術將它取出。在麻醉完成之後，於心臟超音波之中，發現這顆不明物質已經不在右心房內，於是趕緊施行緊急的心肺繞道。外科大夫將兩側的肺動脈打開，結果從右肺動脈沖洗出一顆4 x 1 x 1 cm的血栓來。當快要結束手術時，經食道超音波發現右心房內有另一顆血拴。因此又再次施行了右心房切開以移除這顆血栓。經靜脈心律調節器可能會併發右心房血栓及嚴重的肺栓塞。仔細且連續的心臟超音波監測，對偵測逃逸或殘餘的血栓而言是非常重要的。

We report a 44-year-old male patient who sustained a right atrial (RA) thrombosis with eyolvement into right pul-monary artery embolism in consequence of placement of a temporary pacing lead and was successfully treated with surgical thrombectomy under the guidance of perioperative transesophageal echocardiography (TEE). Because of intermittent complete atrioventricular block he therefore underwent implantation of a transvenous temporary pacing. On the ensuing day a large mass was incidentally found echographically in the RA suggestive of a large thrombus. Immediate surgical removal of the mass was indicated. During the emergent open-heart surgery the mass in RA dehiscenced with fragments migrating to the right main pulmonary artery, and exploration of both the RA and right pulmonary artery was done. This migratory mass, which proved to be a fresh thrombus, was sur-gically removed. The cardiopulmonary bypass was then terminated and the spontaneous contraction of heart was resumed. However, another mass lesion was found in RA on the TEE screen just following the removal of the problematic transvenous pacing wire. The right atrium was thus re-opened immediately and the second thrombus was cleared. Over the on-going surgical course no further abnormal echogenic objects were visible in the cardiac chambers. It is perceivable that transvenous pacing might cause thrombois or dislodgement and dehiscence of thrombi already in existence in the cardiac chamber. Careful and continuous intraoperative surveillance with echocardiography over a patient who is undergoing cardiac embolectomy is quite important in detecting thrombus escape and residual thrombi during surgery.