2003 年 16 巻 2 号 p. 93-96
Transcranial Doppler (TCD) monitoring is now one of the most important monitoring tools during carotid endarterectomy (CEA). We present a case that showed no abnormal findings of TCD during CEA.
The patient was a 65-year-old man with diabetes mellitus and hypertension, who presented with transient left-sided weakness. Presence of a right carotid bruit prompted cerebral angiography, which confirmed severe stenosis of thr right internal carotid artery (ICA). The patient underwent a balloon occlusion test of the right ICA before surgery. During the operation, after removing the atheromatous plaque, there was no back-flow from the right ICA, suggesting occlusion of the latter. Removal of the thrombus and urokinase injection were tried, resulting in recanalization of the ICA. During the procedure, no apparent high-intensity transients (HITs) were detected. However, after declamping the right ICA, only an air bubble was detected by TCD. After the operation, the patient showed no neurological deficits. MR confirmed multiple small infarcts in the right parietal lobe.
The importance of TCD during CEA is beyond all doubt, but we must be aware that TCD sometimes may not detect ICA occlusion in cases with good collateral circulation.