Intraoperative assessment of carotid endarterectomy

The use of operative arteriography during carotid endarterectomy facilitates identification and correction of technical errors. Although arteriography is the standard for assessing surgical results, it prolongs the operation and may increase the overall risk. The purpose of this study was to evaluate pulsed Doppler spectral analysis and arteriography as methods of intraoperative assessment. Operative arteriography was performed in 150 consecutive carotid endarterectomies. In 50 of these cases a sterile 20 MHz pulsed Doppler probe and real-time spectrum analyzer were used to evaluate internal carotid velocity patterns before and after endarterectomy. Operative arteriograms were normal in 127 cases, whereas abnormalities were noted in 16 internal and seven external carotid arteries. Thirteen of the arteriographic defects were considered minor and accepted. Major defects requiring immediate repair occurred in eight (5%) internal and two external carotid arteries. In the 50 cases assessed by both techniques, seven internal carotid arteries had mild flow disturbances both before and after endarterectomy, whereas 38 of the remaining 43 arteries showed improvement in spectral characteristics after endarterectomy. In two patients who failed to show improvement on the initial postendarterectomy evaluation, operative arteriography demonstrated residual defects that required immediate repair. No other technical errors were encountered, and there were no perioperative deaths or neurologic complications in the 150 operations. Intraoperative assessment by pulsed Doppler spectral analysis is a safe, rapid, and accurate method for detecting technical errors during carotid endarterectomy. The high sensitivity of this method (no false negative assessments) makes it an ideal screening test to be used for selection of patients for operative arteriography. By indicating when a technical error is most likely, this approach precludes the need for routine operative arteriography.