Carotid Cross-Clamp intolerance during carotid endarterectomy in regional anesthesia

During surgical endarterectomy, carotid cross clamping is needed for arteriotomy and plaque removal. Carotid cross clamping reduces the blood flow to the circle of Willis, and some patients show intolerance to the temporary occlusion of the internal carotid artery (ICA).

Aim. This study demonstrates locoregional anesthesia’s safety in patients with carotid cross clamping intolerance (CCI) and the risk factors that predict this condition.

Materials and Methods. All patients who underwent surgical carotid endarterectomy between January 2019 and December 2020 (n=53, 29 were male, age (median with range) – 78 (56-90) years) were identified in a retrospective review. The indication for surgical treatment was made for a stenosed ICA of 70-99% or in the case of symptomatic stenosis.

Surgical technique. An incision is made at the front edge of the sternocleidomastoid muscle. The common carotid artery (CCA) is identified and isolated from the surrounding tissues with sharp dissection and continued toward the bifurcation. Next, the internal and external carotid arteries can be isolated. Heparin (5000 U) is administrated intravenously, and the systolic arterial pressure is increased and kept over 160 mm Hg. In the next step, the cross clamping tolerance test is performed for 60 s. During clamping, the patient is neurologically meticulously observed. In the case of CCI, the operation proceeds with the insertion of a temporary shunt. The arteriotomy is started in the CCA and continues to the ICA. The plaque is completely removed, and the arteriotomy incision is covered with a patch. Before completing the suture, the clamps are partially removed to flush out the debris using the blood flow. Now, the external and common artery can be released. Finally, the clamp of the ICA can be removed.

Results. Eight patients had cross clamping tolerance test intolerance. In all these cases, the surgical procedure was continued with a shunt. The further operation course remained uncomplicated. The in-hospital mortality was nil, and a transient ischemic attack occurred in only one case.
Coronary artery disease (CAD) [odds ratio (OR) 12.65, 95% confidence interval (CI) 1.43-112.50], a history of cerebrovascular events [OR 10.50, 95% CI 1.83-60.30], and contralateral stenosis of 70% or more [OR 26.66, 95% CI 2.29-304.37] presented a significant association with the CCI and the need to shunt. The remaining factors showed no significant association with intolerance.

Conclusions. Regional anesthesia is a safe method for identifying patients with CCI and safely performing the surgical procedure. Contralateral stenosis of the ICA and a history of cerebrovascular events are significant factors to predict CCI.