Contralateral stenosis as a risk factor for carotid endarterectomy measured by near infrared spectroscopy.

AIM

It is still controversial whether the existence of a contralateral stenosis is a risk factor during carotid endarterectomy (CEA). We used a near infrared spectroscopy (NIRS) monitoring system during CEA to evaluate the hemodynamic effect of contralateral stenosis during cross clamping of the carotid arteries.

METHODS

We monitored 34 consecutive cases of CEA, using NIRS. Tissue oxygen index (TOI), as a parameter of oxygenation, and total hemoglobin index (THI), as a parameter of blood volume, were measured during cross-clamping the carotid arteries. We evaluated the relationship between these results and the pre- and intraoperative characteristics including the existence of a contralateral stenosis and the results of single-photon emission computed tomography (SPECT).

RESULTS

Bilateral TOI and THI correlated well with the severity of the stenosis of the contralateral internal carotid artery, and ipsilateral THI correlated with the cerebrovascular reserve measured by SPECT.

CONCLUSIONS

A contralateral stenosis is a risk factor for CEA from the hemodynamical point of view, and extreme care should be taken when performing CEA in patients with bilateral stenoses.