Cerebral revascularization using muscle free flap for ischemic cerebrovascular disease in adult patients

The efficacy of encephalo-myo-synangiosis (EMS) using muscle free flap was evaluated for the treatment of ischemic cerebrovascular disease in adult patients. Three patients with adult moyamoya disease and three patients with atherosclerotic ischemic cerebrovascular disease were treated. EMS used four latissimus dorsi muscles and two serratus anterior muscles. Postoperative selective angiography showed collateral circulation from the transferred muscle to the brain in four of the six patients. The other two patients showed patent nutrient artery of the transferred muscle flap. Cerebral blood flow study disclosed postoperative improvement of perfusion reserve capacity in all sides. One patient suffered a perioperative stroke by hemoconcentration due to poor control of diabetes mellitus. The mean follow-up period was 23 months. EMS using muscle free flap is a possible procedure in selected patients with impaired cerebral perfusion reserve capacity due to multiple stenosis or occlusion of cerebral arteries including moyamoya disease or who required cerebral blood flow augmentation in the anterior and/or posterior cerebral artery territories due to internal carotid artery occlusion.     

Surgical treatment of common carotid artery occlusion

Eight patients with common carotid artery (CCA) occlusion underwent bypass with saphenous vein to either the carotid bifurcation (five), the internal carotid artery (two), or the external carotid artery (one). Indications included ipsilateral transient ischemic attack (two), recent nondisabling hemispheric stroke (two), and transient nonhemispheric cerebral symptoms (two). Two asymptomatic patients with CCA occlusion and contralateral internal carotid stenosis underwent prophylactic revascularization prior to planned aortic surgery. There were no perioperative strokes, occlusions, or deaths. Late ipsilateral stroke occurred in two patients, and one patient had a single transient ischemic attack after 2 years. The four patients with preoperative transient cerebral ischemia experienced relief of their symptoms. Duplex ultrasound is an accurate screening modality for distal patency. Collateral filling of the internal or external carotid artery can usually be demonstrated after aortic arch or retrograde brachial contrast injection. End-to-end distal anastomosis after endarterectomy eliminates the original occlusive plaque as a potential source of emboli. The subclavian artery is preferred for inflow on the left. The CCA origin is easily accessible for inflow on the right. Bypass of the occluded CCA is safe and may be effective in relieving transient cerebral ischemic symptoms, although long-term ipsilateral neurologic sequelae may still occur.     

Effectiveness of bupivacaine administered via femoral nerve catheter for pain control after anterior cruciate ligament repair

An 8-year-old girl presented with fibromuscular dysplasia of the intracranial vessels manifesting as ischemic stroke. Neuroimaging showed infarction of the right putamen and ipsilateral frontal white matter. Angiography revealed "string of beads" sign involving the terminal portion of the right internal carotid artery and the horizontal segment of the ipsilateral middle cerebral artery. She was treated conservatively. Magnetic resonance angiography at 2 months post ictus showed similar findings in the middle cerebral artery but improvement of the stenosis of the internal carotid artery. Her neurological deficits had almost resolved. Fibromuscular dysplasia should be part of the differential diagnosis of ischemia in children.     

Insidious rupture of the Achilles tendon after ciprofloxacin-induced tendopathy. A case report

A 64-year-old male patient had two episodes of transient ischemic attack and a cerebral infarction. Cerebral angiography showed 50% stenosis at the junction of left internal carotid artery and 90% stenosis at left mid-cerebral artery (MCA). Coronary angiography showed two vessel disease with arteriosclerotic change and underwent coronary artery bypass grafting. To prevent intraoperative cerebral infarction, we used brain protect solution just before starting ECC, set perfusion flow around 3 l/min/m2, monitored the flow of left MCA using Transcranial Doppler (TCD) and the saturation of left internal jugular vein (SjO2) continuously. PaCO2 was controlled around 45 mmHg. TCD showed good pulsatile flow, and SjO2 was kept over 60%. The patient recovered consciousness 2 hours after operation in the intensive care unit without paresthesia. We thought the number of open-heart cases with cerebrovascular disease increased, and pulsatile low of ECC by intraaortic balloon pumping and the monitoring of SjO2 are useful for the cases.     

Is impaired cerebral vasomotor reactivity a predictive factor of stroke in asymptomatic patients?

BACKGROUND AND PURPOSE: Identification of the subgroup of asymptomatic patients with severe internal carotid artery stenosis and high risk of stroke has important clinical implications. Cerebral vasomotor reactivity provides information regarding intracranial hemodynamic features and might have a prognostic value in predicting cerebrovascular ischemic events, especially in patients with carotid stenosis. The aim of our study was to assess the cerebral vasomotor reactivity in asymptomatic patients with carotid stenosis and evaluate its role in stroke occurrence. METHODS: Cerebral vasomotor reactivity was assessed using transcranial Doppler ultrasonology and the Diamox test (intravenous administration of 1.0 g acetazolamide) in 44 asymptomatic patients with severe (> 70%) internal carotid artery stenosis. Patients were followed up prospectively (mean, 2 years). RESULTS: Cerebral vasomotor reactivity was estimated as good (> 40% increase of blood flow velocity in the middle cerebral artery ipsilateral to the carotid stenosis after undergoing the Diamox test) in 23 patients; it was impaired in the other 21. During the follow-up period, the overall annual rate for ipsilateral stokes was 2.3%; it was 7.9% for all ischemic cerebral events. No strokes or transient ischemic attacks occurred in the former group, but there were 7 cerebral ischemic events (2 strokes [1 fatal] and 5 transient ischemic attacks) in the latter group. There was a statistically significant correlation between cerebral ischemic events and impaired cerebral vasomotor reactivity (P = .009). CONCLUSIONS: The data of this preliminary study suggest an important role of impaired cerebral vasomotor reactivity in predicting ischemic cerebral events. Preventive vascular surgery might be considered in this high-risk subgroup of asymptomatic patients with severe carotid stenosis.     

Bypass surgery for vascular disease of the carotid system

A series of 58 operations on 56 patients, in whom a branch of the superficial temporal artery was anastomosed to a branch of the middle cerebral artery (STA-MCA bypass or Yasargil procedure), is reviewed. These operations were performed chiefly for occlussions or for inaccessible stenotic lesions of the internal carotid or middle cerebral arteries. Patency in eight patients operated on from April 1971 through November 1973 was low (25%). Patency in patients operated on since July 1974 has been high (95%). There have been no deaths and no major ischemic strokes attributable to the surgery. The rationale for this procedure is considered in relationship to the anatomy and physiology of the cerebral circulation and the pathogenesis of syndromes of cerebral ischemia. The operation appears to have a low morbidity in good-risk patients. The role of this operation in managing common manifestations of cerebral vascular disease such as focal transient cerebral ischemic attacks (TIAs) and amaurosis fugax, although not fully established, appears encouraging. The procedure seems useful for orthostatic cerebral ischemia caused by multiple occlusions of major extracranial (and intracranial) vessels and, occasionally, for progressing strokes related to internal carotid artery occlusion, both of which are relatively uncommon manifestations of cerebral vascular occlusive disease. It may have application in the rare "slow stroke." The procedure is probably of limited value, if any, in the management of large completed infarcts but may be indicated in selected patients with small infarctions who have preserved most of their cerebral function and who have had evidence of subsequent focal ischemic events. The procedure is useful for bypassing giant aneurysms or basofrontal tumors invading major vessels. It may have a role in the management of fibromuscular disease of the internal carotid artery.     

Progressive intracranial occlusive disease associated with deficiency of protein S. Report of two cases

BACKGROUND AND PURPOSE: Deficiency of the free fraction of protein S has been associated with arterial or venous stroke. The pathogenesis of vascular occlusion in patients with protein S deficiency is not known. We present two cases of cerebral infarction and deficiency of protein S in which the subjects had progressive intracranial occlusions. CASE DESCRIPTION: A 16-year-old girl was admitted because of left brain stem infarction and protein S deficiency. Cerebral angiography disclosed stenosis of the right intracranial vertebral artery and occlusion of the left posterior cerebral artery. A second angiogram performed 18 months later disclosed occlusion of the right vertebral intracranial artery. In the second case, a 17-year-old girl was admitted because of left hemispheric cerebral infarction and protein S deficiency. Cerebral angiography showed stenosis of the left anterior cerebral artery, left supraclinoid internal artery, and left middle cerebral artery. A second cerebral angiogram performed 5 months later disclosed occlusion of the left anterior cerebral artery and poor hemispheric perfusion through the left middle cerebral artery. CONCLUSIONS: Based on our cases, we postulate that some patients with prothrombotic states may develop progressive intracranial arterial occlusions, possibly secondary to a permanent thrombogenic stimulus. We suggest routinely searching for prothrombotic states in young patients with intracranial occlusion, especially if the occlusion is progressive and other causes are not obvious.     

The role of activators in assembly of RNA polymerase II transcription complexes

Since the negative results of the international Bypass Study, extracranial-intracranial (EC-IC) bypass surgery is infrequently employed in the treatment of patients with cerebral ischemia. Newly acquired evidence concerning the pathophysiology of cerebral ischemia, however, has facilitated the identification of a small subgroup of patients with "hemodynamic" cerebral ischemia. Characteristically, these patients demonstrate severely impaired cerebrovascular reserve capacity due to occlusive disease and insufficient collateral blood supply. Over an 8-year period, 28 patients were defined by clinical and laboratory criteria as suffering from hemodynamic cerebral ischemia. All patients had recurring episodes of focal cerebral ischemia due to unilateral internal carotid artery occlusion. Computerized tomography (CT) scans either were normal or showed evidence of border zone infarction. The cerebrovascular reserve capacity was studied using 133Xe single-photon emission CT and acetazolamide challenge and was found to be significantly impaired in all patients. Based on these criteria, superficial temporal artery-middle cerebral artery anastomosis was performed to augment collateral flow to the ischemic hemispheres. Two patients died from myocardial infarction, one 4 days and the other 2 months postoperatively. One patient died from massive brain infarction and another suffered a postoperative stroke with incomplete recovery, resulting in a major morbidity and mortality rate of 14%. Minor morbidity included one patient with a subdural hematoma who subsequently recovered completely. The postoperative course was uneventful in 23 patients (82%). Over a mean follow-up period of almost 3 years, no patient had another episode of brain ischemia. Bypass patency was confirmed by postoperative angiography in 26 patients. Follow-up studies of cerebral blood flow (CBF) and cerebrovascular reserve capacity showed significant improvement of the latter while the resting CBF was essentially unchanged. In view of these findings, the authors conclude that EC-IC bypass surgery constitutes appropriate therapy for a subgroup of patients with recurrent focal cerebral ischemia, defined using the strict selection criteria employed in this study.     

Spontaneous occlusion of supraclinoid aneurysms after the creation of extra-intracranial bypasses using long grafts: report of two cases

OBJECTIVE: We describe two cases of giant supraclinoid aneurysms, treated by means of saphenous vein grafting between the external carotid artery and the middle cerebral artery, which unexpectedly spontaneously occluded. CLINICAL PRESENTATION: Two patients presented with subarachnoid hemorrhage and headache, respectively. In the first case, angiography showed an aneurysm of the right internal carotid artery (ICA), which had been treated by clipping. Repeat angiography showed a giant aneurysm of the right ICA, the formation of which was probably caused by sliding of the clip that had been applied during the previous operation. The patient was operated on again, but it was impossible to exclude the aneurysm because no clear neck could be identified. In the second case, magnetic resonance imaging and cerebral angiography showed a large, partially thrombosed aneurysm of the supraclinoid segment of the left ICA. TECHNIQUE: In view of the patients' ages and the statuses of compensatory circulation, each patient underwent cerebral revascularization with a long saphenous vein graft placed between one branch of the middle cerebral artery and the external carotid artery, in anticipation of subsequent endovascular treatment of the aneurysm and/or closure of the ICA in the neck. Postoperative angiography demonstrated spontaneous occlusion of the aneurysms. CONCLUSION: Thrombosis of an aneurysm may occur spontaneously or after explorative surgery. However, it should be remembered that spontaneous occlusion of an aneurysm may be induced or favored by hemodynamic vascular alterations that take place inside the aneurysm after a high-flow extra-intracranial bypass has been created.     

Evaluating the effect of superficial temporal artery to middle cerebral artery bypass on pure motor function using motor activation single photon emission computed tomography

OBJECTIVE: We evaluated and analyzed the effect of superficial temporal artery to middle cerebral artery bypass for internal carotid artery occlusion on pure motor function using motor activation single photon emission computed tomography. METHODS: Motor activation single photon emission computed tomographic (SPECT) images were obtained for nine patients who had undergone superficial temporal artery to middle cerebral artery anastomosis for symptomatic internal carotid artery occlusion. All motor activation SPECT images using the finger opposition task on the affected side were obtained before bypass surgery and at 1 week, 1 month, and 3 months after bypass surgery. The results of motor activation single photon emission computed tomography were expressed as negative or positive. RESULTS: Before bypass surgery, the resting SPECT images revealed reduction of cerebral blood flow (CBF) on the affected side in all nine patients. The results of motor activation single photon emission computed tomography in three patients were positive. One week after bypass surgery, the results of the resting and motor activation CBF studies did not demonstrate any marked changes. One month after bypass surgery, the resting CBF increased in four patients. The results obtained for two of the patients revealed preoperative positive motor activation. The results of motor activation single photon emission computed tomography obtained for five patients were positive. Three months after bypass surgery, eight patients experienced improvement in the resting CBF, and the results of motor activation single photon emission computed tomography obtained for seven patients were positive. Among these, the results of preoperative motor activation single photon emission tomography obtained for four patients were negative. CONCLUSION: Superficial temporal artery to middle cerebral artery bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT images. From the preoperative motor activation study, it was concluded that patients with preoperative positive motor activation could attain the effect of bypass earlier than patients with preoperative negative motor activation.     

Anticarcinogenic effect of palustran on development of tumors induced by 3-(1-alpha-L-arabinopyranosyl)-1-methyl-1-nitrosourea (AMNU) in rats

Clinical manifestations of superior sagittal sinus (SSS) thrombosis are nonspecific but characterized by headache, papilledema, seizures, focal deficits, progressive coma and death. Recurrent transient focal neurologic deficit is an extremely rare manifestation in superior sagittal sinus thrombosis and the mechanism is unknown. A 45-year-old man presented with headache for two weeks and four episodes of transient (5-10 minutes) right or left hemiparesis for two days. Magnetic resonance image and transfemoral cerebral angiography revealed superior sagittal sinus thrombosis with numerous prominent collateral venous channels. There was no parenchymal lesion. After four days of heparinization, no further transient focal neurologic deficits developed. Follow-up angiography showed partial recanalization of the SSS. Possible mechanism of transient ischemic attacks in this patient is thought to be a transient functional disturbance due to a temporal reduction of tissue perfusion in the process of operating fully-enough collateral channels.     

Testosterone sulphation and glucuronidation in the human liver: interindividual variability

We present a case with the traumatic extracranial internal carotid artery dissecting aneurysm. A 21-year-old man was involved in a motorcycle accident, resulting in multiple injuries but no apparent head and neck injuries. Head CT was normal on his admission. He was discharged from his local hospital 3 weeks after the accident without any neurological deficits. Five weeks after the accident, he suddenly presented with a motor aphasia and a right hemiparesis. CT and MRI showed infarctions in the left para-Sylvian and the left angular areas. Angiography showed a left extracranial carotid artery dissecting aneurysm at the level of C1 vertebral arch. The patient was initially managed by an anticoagulant agent, but he suffered from another transient ischemic attack due to distal embolism from the aneurysm. Balloon occlusion test of the left ICA was performed under monitoring EEG, SEP. Mean stump pressure (MSP) revealed 60 mmHg. and MSP/Mean systematic blood pressure revealed 67%. We judged that the left ICA ligation was a safe method to treat this patient, however, considering the patient's age and the side of the lesion, left STA-MICA bypass and ligation of the left ICA were carried out in one stage. Postoperatively, the patient did not show any cerebral ischemic complications and angiography showed disappearance of the aneurysm and patency of the bypass. The left MCA territories were filled well by cross circulation and the bypass.     

Surgical treatment of an aortic arch aneurysm: reports of 2 cases with lesion of the arch vessels

A 48-year old woman underwent surgery for an aortic arch aneurysm with stenosis or dilatation of three arch vessels caused by aortitis syndrome. Total arch replacement and reconstruction of three arch vessels were performed with hypothermic selective cerebral perfusion (SCP). To avoid atheroembolism and malperfusion to the brain, the rt. common carotid artery was perfused via the rt. subclavian artery through the dacron vascular graft and the lt. subclavian artery was cannulated and perfused distally to stenosis. A 65-year-old man who had an atherosclerotic aortic arch aneurysm with severe stenosis of the brachiocephalic artery underwent operation. In the operation, extracorporeal circulation was instituted with the arterial return through the lt. subclavian artery. Same as case 1, total arch replacement and reconstruction of three arch vessels were performed under hypthermic SCP. In this case, the left common carotid artery was transected and cannulated directly into the vessel, instead of cannulation through the aortic lumen because of atheromatous plaques in the orifice of the left common carotid artery. The patients recovered uneventfully and doing well now.     

Arteriovenous malformation associated with moyamoya disease

The first case of a child with an arteriovenous malformation (AVM) associated with moyamoya disease is reported. The patient presented ischemic symptoms and underwent indirect bypass surgery on both sides when she was 5 years old. Four years later she suffered from headache, and a small AVM of the left frontal lobe associated with the moyamoya vessels was detected. Single photon emission computed tomography (SPECT) was performed at age 11 and demonstrated low local cerebral blood flow (CBF) in the left frontal lobe and right temporal lobe, although the revascularization after the bypass surgery seemed to be effective, as judged on pancerebral angiography. We feel that brain ischemia due to the moyamoya disease may have played a causative role in the development of the AVM.     

Uncoupling protein-2 messenger ribonucleic acid expression during very-low-calorie diet in obese premenopausal women

An omental flap is useful in reconstructive surgery, but harvesting such a flap generally requires laparotomy. However, endoscopic surgery facilitates harvesting an omental flap without open laparotomy. We performed endoscopic omental harvest in two patients. We described the procedure of endoscopic omental harvest, which is different from that reported previously. Four access ports were required: two placed lateral to the right rectus margin, one placed lateral to the left rectus margin, and one placed in the infraumbilical area. The stomach was suspended from the peritoneum for the dissection of the gastric rami. The vessels from the gastroepiploic arcade to the greater curvature of the stomach were individually clipped and divided. The omentum then was dissected to the transverse colon and the lower portion of the omentum was dissected along the transverse colon. Finally, the right side of the omentum was dissected. The omentum was transferred using the right gastroepiploic vessels for anastomosis. The advantages of endoscopic harvest are an inconspicuous scar, minimal operative pain, and early recovery. The disadvantages include a long procedure time. At the present time, endoscopic harvest of the left side of the omentum is problematic because of difficulty in identifying the left omental artery and the risk of injury to the spleen. However, these limitations will likely be resolved in the future.     

Morphometric analysis of CD4+, CD8+, and gamma/delta+ T-lymphocytes in lymph nodes of cattle vaccinated with Brucella abortus strains RB51 and 19

We have often experienced false positive results of the stress Thallium-201 myocardial scintigraphy (TL) for the evaluation of artery bypass graft patency after coronary artery bypass surgery (CABG). The purpose of this study is to clarify the frequency and the clinical significance of this findings. Sixty-two patients undergoing coronary angiography (CAG) after CABG were studied. These patients had undergone at total of 156 bypasses (artery grafts 108, saphenous vein grafts 48, mean bypass grafts number 2.65/cases), and the mean period from CABG to TL was 41.6 +/- 34 days. The territories of stress induced ischemia were divided into 3 territories; left anterior descending (LAD), right coronary artery (RCA), and left circumflex (LCX) territories. Patency of the bypass grafts was estimated on the absence of transient perfusion defect (TPD) on TL images. The incidence of false positive results was higher in Dipyridamole TL (38%) than in Exercise TL (18%) and higher in LAD territories (38%) than in RCA (11%) and LCX (13%) territories. All false positive cases showed no evidence of chest pain and significant ST-T change during stress TL test. High incidence of false positive results of stress TL test was observed for the evaluation of artery bypass graft patency after CABG.     

One-stage repair of interrupted aortic arch with selective cerebral perfusion

To minimize the neurological compromise after the circulatory arrest, the selective cerebral perfusion could be beneficial. We underwent one-stage repair of the interrupted aortic arch (IAA) with various intracardiac anomalies for the six patients, age ranging from 12 days to 4 months, by using the selective cerebral perfusion. Cardiopulmonary bypass was established by using two-way arterial cannulation supported by the two respective pump systems, one of which utilized the EPTFE graft anastmosed to either the bracheocephalic artery or the right subclavian artery and second of which enrouted through the arterial ductus to the descending aorta. The cerebral perfusion during the circulatory arrest for the aortic arch repair was maintained by the selective perfusion via EPTFE graft with 10 ml/kg/min blood flow. After the completion of the arch repair, the total system perfusion was restarted through the graft and the repair of the intracardiac anomalies was followed. Of six, no operative death or neurological complications related to the operation were found. The clinical neurological evaluation after operation also demonstrated the normal for the age. In conclusion, the selective cerebral perfusion by using the EPTFE graft during the circulatory arrest might decrease the risk of brain damage.     

Rabbit and human atherosclerotic lesions contain IgG that recognizes epitopes of oxidized LDL

In the management of major cerebral artery obstruction, cerebral perfusion reserve is key to introducing cerebral revascularization surgery. The purpose of this study was to evaluate the feasibility of assessing cerebral perfusion reserve by consecutive 99mTc-hexamethyl-propyleneamine oxime (99mTc-HMPAO) SPECT with 5% carbon dioxide (CO2) inhalation. METHODS: The CO2 inhalation and consecutive 99mTc-HMPAO SPECT study was performed on 30 chronic ischemic cerebrovascular disease patients with unilateral major cerebral artery obstruction and on 27 patients without. CO2 reactivity was expressed as the percent increase of 99mTc-HMPAO accumulation from the baseline (%Change) and as a constant k' that was the ratio of 99mTc-HMPAO accumulation per 1 mmHg change of end-tidal CO2 tension by exponential curve fitting. RESULTS: The mean %Change and k' in the middle cerebral artery (MCA) territory on the side without an obstructive lesion or in the cerebellum ranged from 10.0% to 11.1% and from 0.98% to 1.13% per mmHg, respectively. In the MCA territory, an obstructive lesion was noted in 5.9% versus 0.54% per mmHg in the contralateral MCA territory (p < 0.01). Eleven of 30 patients with major cerebral artery obstruction revealed significant asymmetry in the k' value between bilateral MCA territories. CONCLUSION: The results showed compromised cerebral perfusion reserve in the obstructed major cerebral artery territory. The present method was proven clinically useful for evaluating cerebral perfusion reserve in patients with unilateral major cerebral artery obstruction.     

Combined use of duplex imaging and magnetic resonance angiography for evaluation of patients with symptomatic ipsilateral high-grade carotid stenosis

PURPOSE: Advances in cerebral vascular imaging suggest that patients with critical levels of carotid artery stenosis (> 70%) who have symptoms can be identified accurately and necessary information about the intracranial and extracranial circulation obtained before surgery without conventional angiography. We have used carotid duplex imaging in combination with magnetic resonance angiography (MRA) to evaluate 20 patients with symptomatic ipsilateral high-grade carotid stenosis. METHODS: All patients underwent CT and magnetic resonance imaging brain scans, as well as MRA and conventional arteriography of the cerebral circulation. Magnetic resonance angiograms were obtained with two-dimensional phase contrast and time-of-flight techniques. Phase contrast was used for intracranial vascular imaging and for determining qualitative flow velocities and the direction of blood flow in the circle of Willis. Two-dimensional time of flight was used to assess the carotid bifurcations. RESULTS: Twenty patients with symptoms (six with strokes, 11 with transient ischemic attacks, and three with amaurosis fugax) had duplex evidence of high-grade carotid stenoses. Computed tomographic and magnetic resonance brain scans were positive for cerebral infarction in six patients with clinical strokes. Comparison of MRA with conventional angiography was 91% accurate for high-grade stenoses and occlusions (sensitivity 100% and specificity 90% for stenosis; sensitivity/specificity was 100% for complete occlusion). Comparison of duplex imaging with conventional angiography demonstrated 86% accuracy for detection of severe stenosis or occlusion (sensitivity 94% and specificity 89% for stenosis; sensitivity and specificity were 100% for complete occlusion). CONCLUSIONS: This study suggests that combined use of MRA and duplex imaging is accurate for detection and evaluation of high-grade carotid stenoses in patients with symptoms.     

Histological studies of intracranial vessels in primates following transluminal angioplasty for vasospasm

Percutaneous transluminal angioplasty for treatment of cerebral vasospasm was performed in primates. Chronic cerebral vasospasm was induced by placement of an autologous blood clot over the right internal carotid artery (ICA), middle cerebral artery (MCA), and anterior cerebral artery (ACA). Cerebral angiography on Day 7 showed that the diameters of the ICA, MCA, and ACA were reduced to 55.7% +/- 1.3%, 55.3% +/- 2.6%, and 59.6% +/- 1.3%, respectively, of baseline. The angioplasty was carried out with a silicone microballoon attached to a microcatheter under somatosensory evoked potential (SEP) monitoring on Day 7. The angioplasty for ICA was performed satisfactorily; however, the balloon could not be advanced to the spastic M1 or A1 portions of the cerebral artery. Following angioplasty, the diameters of the ICA, the M1 segment, and the A1 segment were 79.6% +/- 2.9% (p < 0.001), 67.6% +/- 4.3% (p < 0.05), and 61.7% +/- 2.2% (not significant), respectively, of baseline. Histological studies demonstrated that the vessels were well dilated and patent without endothelial cell damage.