Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and XXXX -dependent adaptation.

@entity1 @entity63 @entity409 @entity51 @entity6455 @entity850 @entity543 @entity385
OBJECTIVE: Hemodynamically relevant internal carotid artery (ICA) @entity850 is a major cause of @entity385 . Despite its long-term benefit, carotid endarterectomy may also be associated with severe @entity51 . Intraoperative and early recognition of @entity63 in the region of the ICA may reduce this risk. To date, direct imaging and quantitative analysis of microvascular structures and function in the @entity1 ICA region have not been possible. We purposed to visualize and quantify @entity63 /reperfusion-induced microcirculatory changes in the terminal vascular bed of the ICA in @entity1 undergoing unilateral ICA endarterectomy. METHODS: Sequential analysis of the ipsilateral and contralateral conjunctival microcirculation was performed with orthogonal polarized spectral imaging in 33 @entity1 undergoing unilateral ICA endarterectomy because of moderate or severe @entity543 (North American Symptomatic Carotid Endarterectomy Trial score, 75% +/- 13%), before clamping the @entity6455 (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 @entity409 , which was significantly less pronounced than that observed during the first clamping. The individual degree of @entity543 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 @entity850 and development of collateral compensatory circulation in the vascular region of the @entity1 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.
