Chen Chin-I, Iguchi Yasuyuki, Garami Zsolt, Malkoff Marc D, Smalling Richard W, Campbell Morgan S, Alexandrov Andrei V
Stroke Treatment Team, University of Texas, Houston, USA.
Cerebrovasc Dis. 2006;21(4):223-8. doi: 10.1159/000091218. Epub 2006 Jan 27.
The newly developed multi-frequency transcranial Doppler (TCD) is able to differentiate gaseous from solid emboli. Our goal was to apply this technology to initially characterize emboli detected during carotid stenting with distal protection.
Patients undergoing carotid angiography and stenting were monitored with 2-2.5 MHz TCD (Embo-Dop, DWL) over the middle cerebral artery unilateral to stent deployment. Sonographers insured optimal signal recordings during the procedures. Automated emboli detection and classification software (MultiXLab version 2.0) was applied for offline count and analysis. Monitoring using the Filter Wire EX (Boston Scientific) and ACCUNET system (Guidant Corporation) was performed.
A total of 9,649 embolic signals were detected during 11 angiographic and 10 stenting procedures. An observer confirmed the signals using the International Consensus definition. Automated software classified these events into 5,900 gaseous and 3,749 solid emboli. During contrast injections without the protection device, 1,013 emboli were detected with 28% of these being solid. With deployment of the distal protection device, 8,636 emboli were found with 40% being solid (p < 0.001). During stenting and angioplasty with the protection device, 7,395 emboli with 42% solids were detected (p < 0.001). Finally injection of contrast after the procedure, with the protection device still deployed, yielded 1,241 emboli with 31% solids (NS). Only 1 patient developed transient hemiparesthesia during ballooning that reduced the flow velocity to zero for 14 s. Neither gaseous nor solid emboli resulted in a mean flow velocity decrease or clinical symptoms.
Microembolization frequently occurs during stenting even with deployment of the distal protection device. More solid emboli are seen during manipulations associated with lesion crossing. Although novel TCD methods yield a high frequency of embolic signals, further validation of this technique to determine the true nature, size, and number of emboli is needed.
新开发的多频经颅多普勒（TCD）能够区分气态栓子和固态栓子。我们的目标是应用这项技术初步描述在使用远端保护装置的颈动脉支架置入术中检测到的栓子特征。
对接受颈动脉血管造影和支架置入术的患者，在支架置入侧大脑中动脉上方使用2 - 2.5兆赫的TCD（Embo - Dop，DWL）进行监测。超声检查人员在操作过程中确保获得最佳信号记录。使用自动栓子检测和分类软件（MultiXLab版本2.0）进行离线计数和分析。同时使用Filter Wire EX（波士顿科学公司）和ACCUNET系统（Guidant公司）进行监测。
在11次血管造影和10次支架置入手术过程中，共检测到9649个栓塞信号。一名观察者使用国际共识定义对这些信号进行了确认。自动软件将这些事件分类为5900个气态栓子和3749个固态栓子。在未使用保护装置进行造影剂注射时，检测到1013个栓子，其中28%为固态。在部署远端保护装置后，发现8636个栓子，其中40%为固态（p < 0.001）。在使用保护装置进行支架置入和血管成形术过程中，检测到7395个栓子，其中42%为固态（p < 0.001）。最后，在手术后仍部署保护装置的情况下注射造影剂，产生了1241个栓子，其中31%为固态（无统计学意义）。只有1名患者在球囊扩张过程中出现短暂性偏瘫，血流速度降至零持续14秒。气态和固态栓子均未导致平均血流速度降低或出现临床症状。
即使部署了远端保护装置，在支架置入过程中微栓塞仍频繁发生。在与病变穿越相关的操作过程中可观察到更多的固态栓子。尽管新型TCD方法产生的栓塞信号频率很高，但仍需要进一步验证该技术以确定栓子的真实性质、大小和数量。
