Yong Pil Cho

The anatomy of the circle of Willis as a predictive factor for intra-operative cerebral ischemia (shunt need) during carotid endarterectomy

Abstract The collateral flow to the cerebral hemisphere after carotid cross clamping during carotid endarterectomy is mainly through the circle of Willis, and the circle is incomplete in the majority of cases. A correlation between the status of the circle of Willis and the necessity of shunting was evaluated in 67 carotid endarterectomies with pre-operative four-vessel cerebral angiogram. All carotid endarterectomies were performed with selective shunting, based on the change of consciousness and motor function after carotid test clamping under regional anesthesia. Of the 55 patients with either an anterior or a posterior communicating artery, only four (7.3%) required shunting. Twelve patients had neither anterior nor posterior communicating artery, and 10 (83.3%) showed signs of cerebral ischemia necessitating shunting. Mandatory shunt was significantly higher in patients with absence of collaterals (p = 0.00). The rate of intraoperative cerebral ischemia was significantly higher in patients with poor collateral circulation defined by the anatomy of the circle of Willis. [Neurol Res 2002; 24: 237-240]

Carotid endarterectomy with bovine patch angioplasty: a preliminary report.

Carotid endarterectomy with patch angioplasty is a durable procedure for prevention of recurrent neurological symptoms and stroke. However, no definitive study has demonstrated a clear benefit of one class of the patch material over another. The aim of this study was to evaluate the clinical outcome of carotid endarterectomy with bovine pericardium patch in comparison with autologous vein patch. One hundred and twenty-two carotid endarterectomies were performed using patch closure of the arteriotomy with bovine pericardium (61 cases) and autologous vein (61 cases) between September 1995 and June 1999. Though this is not a double-blind type randomized comparative study, effort was made to achieve a 1:1 ratio in sequence with a few exceptions such as non-available veins at time of surgery or for future use. In bovine pericardium patch closure group, the mean total operating time was significantly shorter than autologous vein closure group (P<0.01), but the mean carotid clamping time was similar in both groups, regardless of the use of shunt. The incidence of postoperative local complications including groin wound was less in bovine pericardium patch closure group. The patients were followed with duplex scans in one month post-CEA and 6 months interval thereafter. During the follow-up period, three patients developed non-critical stenosis (two in bovine and one in vein patch), and one aneurysmal dilation occurred in vein patch group. The incidence of restenosis was similar in both groups. Although this is a preliminary report, it is concluded that the results of carotid angioplasty using bovine pericardium compare favorably with autologous vein.

Inflammatory pseudotumor of carotid artery: a case report

Inflammatory pseudotumor is an uncommon round and spindle cell proliferative lesion of unknown etiology that occurs most commonly in the lung. But it also occurs in diverse extrapulmonary locations such as the abdomen, retroperitoneum, pelvis, heart, head and neck, upper respiratory tract, trunk, bladder and extremities. The extrapulmonary inflammatory pseudotumor is often larger, less well circumscribed and multinodular. Proximity of the tumor to vital structures or involvement of vital organs compromises the opportunity for complete resection, thus higher recurrence rates are often reported even after surgical treatment. The authors report a case of inflammatory pseudotumor originating from the common carotid artery in a 42-year-old female patient with a rapidly growing neck mass, treated by en-bloc resection of inflammatory pseudotumor and a long segment of common carotid artery followed by PTFE graft interposition.

Gait improvement after carotid endarterectomy

A prospective study was performed to investigate whether carotid endarterectomy was accompanied by changes in the cerebral circulation and gait of patients with gait disturbance caused by cerebral ischemia from an internal carotid artery flow lesion. Gait analysis was performed pre-and postoperatively in 16 patients who had a gait disturbance from April 1997 to May 1998. A correlation between change of volume flow measured by duplex sonography, a change in cerebral perfusion (CP) by single photon emission computed tomography (SPECT), the status of collateral circulation by cerebral angiogram or magnetic resonance angiogram, and improvement of gait disturbance was analyzed. Of 16 patients with gait disturbance, 14 (87.5%) showed improvement in various gait analysis parameters. Statistical significance was noted in cadence, speed, stride length, step time, and knee range of motion (P<05). Dramatic gait improvement was observed in 8 patients who had markedly increased Doppler volume flow after carotid endarterectomy. Among those 8 patients, 7 had a significant increase of CP as measured by SPECT and an incomplete circle of Willis. In conclusion, the most significant gait improvement was noted in patients who had severely decreased preoperative volume flow, an incomplete circle of Willis, and significantly increased postoperative CP as measured by SPECT.

B-mode Ultrasound Imaging in Symptomatic Internal Carotid Artery Stenosis: Correlation with Clinical and Operative Findings

B-mode ultrasound (duplex) imaging is a technique that enables the evaluation of plaque characteristics. The purpose of this study was to determine the accuracy and usefulness of duplex imaging by comparing a relationship between the preoperative clinical neurologic status, preoperative duplex findings, and operative findings in patients who had carotid endarterectomy (CEA) for symptomatic high-grade internal carotid artery (ICA) stenosis. Sixty patients with symptomatic ICA stenosis who underwent CEA from September 1995 to August 1998 were included in this study. Plaque morphology was categorized in terms of echogenicity by preoperative duplex imaging. A correlation between the frequency of preoperative ischemic stroke and duplex and operative findings was prospectively evaluated. Thirty-eight patients had recent and multiple cerebral ischemia, and 22 experienced a single episode more than 1 month before CEA. Recent and multiple events occurred in 24 (72.7%) of 33 patients with echolucent plaques, but only 6 (40.0%) of 15 with echogenic plaques (p<0.05). Thirty-six (75%) of 48 patients with soft plaques by operative findings had recent and multiple events, but only two (16.7%) of 12 with calcified plaques experienced recent and multiple events (p<0.01). Overall sensitivity, specificity, and accuracy of duplex imaging were 79.5%, 77.8%, and 79.2%, respectively. Duplex imaging is reliable in determining ICA plaque characteristics. Recent and multiple cerebral ischemia occurred more frequently in patients with echolucent plaques by preoperative duplex and soft plaques by operative findings. The presence of echolucent plaque may be used as a strong indication for CEA in patients who have asymptomatic high-grade ICA stenosis.