Drews T, Pasic M, Buz S, Unbehaun A, Dreysse S, Kukucka M, Mladenow A, Hetzer R
Deutsches Herzzentrum Berlin, Berlin, Germany.
Thorac Cardiovasc Surg. 2011 Jun;59(4):237-42. doi: 10.1055/s-0030-1250495. Epub 2011 Mar 25.
Transapical aortic valve implantation (TAVI) is a new method that might reduce the surgical risk of conventional surgical aortic valve replacement in very high-risk patients. Increased downstream microembolization is expected in transapical aortic valve implantation. However, whether it usually occurs, how often, and its clinical relevance are not known. We report the results of ultrasound microembolic signal detection in the middle cerebral artery during the procedure.
Fifty patients (mean age: 80 ± 5 years; mean EuroSCORE: 36 ± 13 %) underwent transapical aortic valve implantation. Intraoperative transcranial Doppler (TCD) sound examination of both middle cerebral arteries (MCA) was used to identify high-intensity transient signals (HITS) and microembolic signals (MES) during seven phases of the procedure. Pre- and postoperative computed tomography of the brain and clinical neurological examinations were performed preoperatively and daily during the first postoperative week.
During the procedure, HITS [right MCA: 435 ± 922 (range 9-5765); left MCA: 471 ± 996 (range 24-6432)] and MES [right MCA: 78 ± 172 (range 1-955); left MCA: 62 ± 190 (range 2-1553)] were detected in all patients. Most of the MES were recorded during valvuloplasty [right MCA: 3 ± 5.6 (range 0-31); left MCA: 2 ± 4.9 (range 0-30)] and positioning of the prosthetic valve in the aortic position [right MCA: 6 ± 5 (range 0-22); left MCA: 2 ± 6.9 (range 0-38)]. Postoperatively, there were no clinical signs of new cerebral embolism.
Cerebral microemboli were detected by intraoperative transcranial Doppler sound examinations in all patients during transapical aortic valve implantation. Most of the signals were detected during balloon valvuloplasty and delivery of the prosthetic valve.
经心尖主动脉瓣植入术（TAVI）是一种新方法，可能降低极高风险患者进行传统外科主动脉瓣置换术的手术风险。经心尖主动脉瓣植入术中预计下游微栓塞会增加。然而，其是否通常发生、发生频率及其临床相关性尚不清楚。我们报告了该手术过程中大脑中动脉超声微栓子信号检测的结果。
50例患者（平均年龄：80±5岁；平均欧洲心脏手术风险评估系统评分：36±13%）接受了经心尖主动脉瓣植入术。术中对双侧大脑中动脉（MCA）进行经颅多普勒（TCD）听诊，以在手术的七个阶段识别高强度瞬态信号（HITS）和微栓子信号（MES）。术前及术后第一周每天进行脑部术前和术后计算机断层扫描以及临床神经学检查。
手术过程中，所有患者均检测到HITS[右侧MCA：435±922（范围9 - 5765）；左侧MCA：471±996（范围24 - 6432）]和MES[右侧MCA：78±172（范围1 - 955）；左侧MCA：62±190（范围2 - 1553）]。大多数MES记录于瓣膜成形术期间[右侧MCA：3±5.6（范围0 - 31）；左侧MCA：2±4.9（范围0 - 30）]以及人工瓣膜在主动脉位置的定位过程中[右侧MCA：6±5（范围0 - 22）；左侧MCA：2±6.9（范围0 - 38）]。术后，无新的脑栓塞临床体征。
经心尖主动脉瓣植入术期间，通过术中经颅多普勒听诊在所有患者中均检测到脑微栓子。大多数信号在球囊瓣膜成形术和人工瓣膜输送期间检测到。
