Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation
Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation
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DOI：
10.1067/mva.2003.139
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发表时间：
2003-04-01
影响因子：
4.3
通讯作者：
Haas, NP
中科院分区：
文献类型：
--
作者：
Schaser, KD;Settmacher, U;Haas, NP
目的：血流动力学相关的颈内动脉（ICA）狭窄是缺血性脑卒中的主要原因。尽管长期受益，颈动脉内膜切除术也可能与严重的神经功能缺损有关。术中和早期识别ICA区域的缺血可以降低这种风险。迄今为止，还不可能对人类ICA区域的微血管结构和功能进行直接成像和定量分析。我们的目的是可视化和量化单侧ICA动脉内膜切除术患者ICA末端血管床缺血/再灌注引起的微循环变化。对33例因中度或重度颈动脉狭窄而行单侧颈动脉内膜切除术的患者（北美症状性颈动脉内膜切除术试验评分，75%至13%），在夹紧颈动脉（基线）之前，在夹紧颈外动脉和颈动脉期间，在颈动脉再灌注期间（腔内分流术），对同侧和对侧结膜微循环进行了正交偏振光谱成像的序列分析。在第二次夹持ICA（移除分流器）期间，颈外动脉和ICA去钳（再灌注）后，以及第二次ICA再灌注后15 ~ 20分钟。结果：颈动脉分流置入ICA时，同侧和对侧结膜毛细血管灌注明显减少，颈动脉分流再灌注后完全恢复。为了移除分流器而重新夹紧ICA会导致微血管功能障碍，这比第一次夹紧时观察到的微血管功能障碍明显不那么明显。首次夹持ICA时，个体ICA狭窄程度与同侧和对侧结膜功能毛细血管密度下降呈负相关。这些结果提示毛细血管灌注随狭窄的增加和侧支代偿循环在人类ICA血管区发展的适应性机制。单侧ICA重建期间的结膜正交偏振光谱成像可以对ICA末端区域的双侧结膜微循环进行连续无创分析，并可以在动脉内膜切除术期间和之后监测有效的颈动脉分流灌注。
Objective: Hemodynamically relevant internal carotid artery (ICA) stenosis is a major cause of ischemic stroke. Despite its long-term benefit, carotid endarterectomy may also be associated with severe neurologic deficits. Intraoperative and early recognition of ischemia in the region of the ICA may reduce this risk. To date, direct imaging and quantitative analysis of microvascular structures and function in the human ICA region have not been possible. We purposed to visualize and quantify ischemia/reperfusion-induced microcirculatory changes in the terminal vascular bed of the ICA in patients undergoing unilateral ICA endarterectomy.Methods. Sequential analysis of the ipsilateral and contralateral conjunctival microcirculation was performed with orthogonal polarized spectral imaging in 33 patients undergoing unilateral ICA endarterectomy because of moderate or severe ICA stenosis (North American Symptomatic Carotid Endarterectomy Trial score, 75% t 13%), before clamping the ICA (baseline), during clamping of the external carotid artery and ICA, during reperfusion of the ICA (intraluminal shunt), during the second clamping of the ICA (shunt removal), after declamping (reperfusion) of the external carotid artery and ICA, and 15 to 20 minutes after the second ICA reperfusion.Results: During ICA clamping for shunt placement, ipsilateral and contralateral conjunctival capillary perfusion was significantly decreased, but it was completely restored after reperfusion with carotid shunting. Reclamping of the ICA for shunt removal caused microvascular dysfunction, which was significantly less pronounced than that observed during the first clamping. The individual degree of ICA stenosis was inversely correlated with the ipsilateral and contralateral decrease in conjunctival functional capillary density during the first ICA clamping.Conclusions. These results suggest adaptive mechanisms of capillary perfusion with increasing stenosis and development of collateral compensatory circulation in the vascular region of the human ICA. Conjunctival orthogonal polarized spectral imaging during unilateral ICA reconstruction enables continuous noninvasive analysis of bilateral conjunctival microcirculation in the terminal region of the ICA and enables monitoring for efficient carotid shunt perfusion during and after endarterectomy.