We have routinely carried out ultrasonographic examination during carotid endarterectomy (CEA) since 2006 for prevention of intraoperative complications. A small－sized probe (linear type,7–15MHz, about3cm in length) is used. Direct application of the probe to the carotid artery can yield more detailed information on plaque characteristics than that obtained through the skin before CEA. If plaque is vulnerable, the stenotic site must be manipulated so as to avoid direct pressure on the plaque for prevention of plaque rupture, which could induce cerebral embolism. Detection of the distal end of stenosis of the internal carotid artery and other plaques that are located in the common carotid artery is essential for safe clamping of these arteries and for insertion of an intraluminal shunt tube. After closure of the arteriotomy, ultrasonographic examination is able to confirm that the lumen is not immediately occluded or stenotic. The present results indicate the effectiveness of interaoperative ultrasonographic examination for prevention of operative complications.
Objective : In order to elucidate whether the elasticity of plaques evaluated using the echo tracking method is related to plaque echo density or pathological findings, we studied patients with carotid stenosis. Methods : We carried out carotid ultrasonographic examination in 21 patients with carotid stenosis exceeding 90% in area, evaluated the echo density of the plaques, and measured the β and Ep values by echo tracking. We then compared the β and Ep values in relation to echo density. Moreover, in patients undergoing carotid endarterectomy, the β and Ep values were also compared with the pathological features of the plaque. Results : There were12low-echoic plaques in12patients (low－echoic plaque group) and9iso－hyperechoic plaques in9patients (iso－hyperechoic plaque group). The β and Ep values in the low－echoic group were significantly lower than those in the iso－hyperechoic group (β, 7.3 ± 2.6 vs. 14.0 ± 6.9, p < 0.005, Ep, 101.4 ± 32 vs. 200.7 ± 101, p < 0.005, respectively). Six patients underwent carotid endarterectomy. The AHA tissue type of the plaques was type VI in4cases and V in the other 2. The β and Ep values of the type VI plaques were lower than those of the type V plaques. Conclusions : It seems that the β and Ep values evaluated by the echo tracking method are related to the echo density and tissue characteristics of plaque.
As a result of technological progress, ultrasonography systems are becoming smaller and more compact. The SonoSite 180PLUS measures 32 × 18 × 5 cm and weighs 2.5 kg. Its excellent portability allows neurosurgeons to perform ultrasonography anywhere in the hospital. Several probes have been developed for each organ. The C15 probe is used to evaluate thoracic and abdominal lesions. Thus, cardiac functions such as cardiac output and ejection fraction can be measured quantitatively. The L38 linear probe is useful for evaluating vascular lesion such as carotid artery stenosis. Additionally, we employ this system when performing catheterization of the central venous system. Using the C11 probe, any mass lesion can be evaluated during neurological surgery. The ultrasound image is merged with the navigation MR image, and the degree of removal can be confirmed. This small, portable ultrasonography system is convenient for evaluation of various lesions at the bedside, and also in the emergency room and operating room, yielding a great amount of information for neurosurgical management.
A 66-year－old man was admitted with dizziness, and suffering from hypertension, hyperlipidemia, brain hemorrhage, and brain infarction. There was a difference in blood pressure between the right arm (77/61 mmHg) and the left (120/60 mmHg) , and the pulse of the right radial artery was markedly diminished. A systolic bruit was audible in the right supraclavicular fossa. Doppler ultrasonography demonstrated a "post-stenotic pattern" in the right vertebral artery (VA) and right common carotid artery (CCA) , characterized by diminished peak systolic flow velocity. We then performed aortic arch angiography and confirmed the presence of severe innominate artery stenosis. The stenosis was successfully treated by balloon angioplasty and stenting. After the treatment, the pulse of the right radial artery became easily palpable, the post－stenotic pattern by Doppler ultrasonography normalized, and the blood pressures in the bilateral arms equalized. When Doppler ultrasonography indicates a post－stenotic pattern in the right VA and the right CCA, stenosis of the innominate artery and occlusion of the left VA should be investigated.
A 47-year-old man was admitted to our hospital because of left upper extremity paralysis sustained during a combative sport. He complained of neck discomfort but was alert, and his NIHSS was 2/42. There was no early CT stroke sign on CT. An MRI diffusion image revealed no early cerebral infarction. Carotid ultrasonography demonstrated no stenosis from the right common carotid to the right internal carotid artery (ICA). The left / right common carotid artery (CCA) end－diastolic velocity ratio was increased to 2.6, and the pulsatility index (PI) of the right CCA was 4.18. These findings suggested stenosis or obstruction of the right ICA. Cervical MRA demonstrated a pearl and string sign in the right ICA. Therefore, the patient was diagnosed as having traumatic right ICA dissection. We ligated the right ICA and reconstructed it employing a high－flow bypass 3 weeks after admission because of a dissecting aneurysm of the ICA and miserly perfusion of the watershed region in the right cerebral hemisphere. This case emphasizes the usefulness of cervical ultrasound examination with pulse Doppler for diagnosis of an ICA stenotic lesion including dissection.