Kanji Yamane

Effectiveness of Superficial Temporal Artery–Middle Cerebral Artery Anastomosis in Adult Moyamoya Disease Cerebral Hemodynamics and Clinical Course in Ischemic and Hemorrhagic Varieties

BACKGROUND AND PURPOSE The efficacy of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in adult moyamoya disease was evaluated by clinicopathophysiological studies. METHODS Fifteen patients with cerebral ischemic attacks (ischemia group) and 15 patients with intracranial hemorrhages (hemorrhage group) were investigated. Clinicoangiographic features and regional cerebral blood flow (rCBF) of the MCA territory were preoperatively and postoperatively investigated, and cortical arterial pressure (CAP) and anastomotic blood flow (AF) were intraoperatively measured. RESULTS In the ischemia group, the preoperative rCBF of 38.4 mL/100 g per minute was significantly increased to 42.1 mL/100 g per minute with a diminution of angiographic moyamoya vessels in 67% of patients after surgery. The mean CAP and AF were 25.6 mm Hg and 34.7 mL/min, respectively. Proximal and distal cerebral vascular resistance (PCVR = [Mean Systemic Arterial Blood Pressure-Mean CAP]/rCBF and DCVR = [Mean CAP/rCBF]) were 1.78 and 0.68, respectively. One patient died perioperatively as a result of intracerebral hemorrhage. During follow-up (mean, 67 months), 12 of 14 patients recovered without neurological deficits, 1 was moderately disabled because of the initial insult, and another patient experienced an intracerebral hemorrhage but recovered fully. In the hemorrhage group, the preoperative rCBF of 38.0 mL/100 g per minute was significantly increased to 42.7 mL/100 g per minute with a diminution of moyamoya vessels in 60% after surgery. The mean CAP and AF were 29.1 mm Hg and 24.1 mL/min, respectively. PCVR and DCVR were 1.72 and 0.77, respectively. One patient became hemiparetic because of perioperative intracerebral hemorrhage. During follow-up (mean, 94 months), 3 patients had fatal intracranial hemorrhages, 10 had good recoveries, and 2 had moderate disabilities. CONCLUSIONS This study revealed a high PCVR and a very low DCVR in both the ischemia and hemorrhage groups of patients. STA-MCA anastomosis partially normalized cerebral circulation and decreased moyamoya vessels but did not completely prevent rebleeding.

Comparison of transcranial Doppler investigation of aneurysmal vasospasm with digital subtraction angiographic and clinical findings.

OBJECTIVE Transcranial Doppler (TCD) findings for evaluation of the severity of vasospasm (VSP) in patients with ruptured aneurysmal subarachnoid hemorrhage are controversial. To clarify these TCD findings, intra-arterial digital subtraction angiography was used to simultaneously investigate the angiographic features of cerebral vessels and the cerebral circulation time (CCT). METHODS Fifty patients with ruptured aneurysms, for whom computed tomographic scans indicated Fisher Grade III subarachnoid hemorrhage, were investigated. Aneurysmal neck clipping was performed in the acute stage. The mean flow velocity (MFV) at the M1 segment was measured using TCD ultrasonography. Intra-arterial digital subtraction angiography was used to simultaneously investigate angiographic features and CCTs on Days 7 to 13. The CCT was defined as the time difference between the two peaks in optical density curves recorded at the carotid artery (C3-C4 portion) and the ascending vein, after contrast material injection. Angiographic VSP was categorized using a modification of the Fisher classification. RESULTS Angiograms for 9, 25, and 16 patients showed no, slight to moderate, and severe VSP, respectively. The MFVs of the patients with no, slight to moderate, and severe VSP were 70, 115, and 116 cm/s, respectively. No significant difference among the three groups could be observed. The mean CCTs of the patients with no, slight to moderate, and severe VSP were 4.1, 4.6, and 6.5 seconds, respectively. The CCTs of the patients with severe VSP differed significantly from those of the patients with no or slight to moderate VSP. The patients with severe VSP were divided into two groups. One group included eight patients with severe VSP at proximal sites (the internal carotid artery to the M1 segment), and the other included eight patients with severe VSP extending to the M2 segment and more peripheral sites. The mean CCT of the former group (5.3 s) was significantly different from that of the latter (7.5 s), and the MFV of the former group (128 cm/s) was significantly higher than that of the latter (81 cm/s). The clinical outcomes for the latter patients were more serious than those for the former patients. CONCLUSION This study suggests that the MFV at the M1 segment is inadequate for estimation of the severity of VSP extending to vessels more peripheral than the M1 segment. Furthermore, severe VSP extending to more peripheral sites can produce more serious ischemic insults, compared with that localized to basal vessels. Patients with negative TCD results and clinical features suggesting the development of VSP should undergo quantitative investigation of cerebral circulatory parameters, such as the CCT, using intra-arterial digital subtraction angiography.

A newly developed shunt system for carotid surgery: T-shaped silicone shunt tubes and clamping devices: technical note.

BACKGROUND Although the use of a shunt during carotid endarterectomy has been controversial, a convenient shunt system is still required. METHODS We have devised an intraluminal shunt system, T-shaped silicone shunt tubes, and clamping devices for carotid surgery. The tube has enough pliability and length to be used in a looped or U-shaped mode and constructs a T-shape with a side arm available for monitoring blood pressure in the shunt system. Clamping devices, such as modified Sugita ring clips and encircle type bulldog clamps, make it possible to hold the tube by a simple maneuver and to minimize the intimal damage. RESULTS This shunt system has been used in 170 carotid endarterectomies and other 10 carotid surgical operations, and the mortality and morbidity rates were 0% and 2.4%, respectively. CONCLUSION This shunt system can be safely and easily used for cervical carotid surgery.

Clinical findings in patients with recurrent in tracerebral hemorrhage

BACKGROUND The use of computerized tomography has led to the detection of second intracerebral hemorrhage (ICH) in some patients. There have, however, only been a few clinical studies of second ICH. SUBJECTS AND METHODS Thirty patients with a second ICH were analyzed according to clinical criteria. These patients comprised 5.9% of all patients admitted to Chugoku Rosai Hospital for ICH between 1984 and 1992. RESULTS The mean interval between the first and second ICH was 27.7 months (range 1-144). The incidence of second hemorrhage was especially high within the first year after the initial ICH. Twelve patients bled bilaterally into the basal ganglia or thalamus during either the first or second attack. Most of these patients had poor outcomes and prognoses. The nine patients with good prognoses included patients with high activity of daily living (ADL) prior to the second attack, and those with neurologic grade 1 following the second attack. All of these patients were managed with conservative therapy. The 10 patients who underwent surgery had poor prognoses. CONCLUSIONS The incidence of second ICHs is greater than that of initial ICHs. Many patients who experience a second ICH will have a poor prognosis, possibly worse than expected. Surgical therapy should not be recommended in such patients, since our data suggest that they will not do well even after surgery.

Traumatic dissection of the common carotid artery after blunt injury to the neck

BACKGROUND Occlusive lesions of the common carotid artery (CCA) resulting from blunt injury are extremely rare, and their clinicopathologic and therapeutic features have not yet been clarified. OBJECTIVES AND RESULTS Five patients with occlusive lesions of the CCA developed neurologic deficits at 1.5 hours to 10 years after blunt neck injury. Lesions included two complete occlusions, one severe stenosis, and two segmental intimal dissections of the CCA. In the two patients with CCA occlusion, bypass surgery was performed using a Dacron graft between the ipsilateral subclavian artery and the carotid bifurcation. In the remaining three patients, the involved segments were replaced with a Dacron graft. Surgical specimens from the early posttraumatic period revealed intimal tears with mural thrombosis and/or subintimal hematomas and those from the later period showed myointimal hyperplasia or fibrotic organization. CONCLUSION Traumatic occlusive lesions of the CCA tend to evolve from intimal dissections to severe stenoses or occlusion, compromising cerebral circulation. The involved CCA can be diagnosed early by B-mode Doppler sonography and successfully reconstructed using a Dacron graft.

Primary pineal melanoma with long-term survival: Case report

A rare case of primary pineal melanoma is reported. The patient was a 53-year-old woman who complained of a severe headache. Computed tomography and magnetic resonance images revealed obstructive hydrocephalus caused by a mass lesion in the pineal region. A biopsy was performed through an occipital transtentorial approach. A black pigmented solitary tumor was seen without leptomeningeal dissemination. Histologic examination revealed melanoma. Chemotherapy consisting of dacarbazine, ACNU, vincristine, and interferon was used. Follow-up imaging studies showed dramatic reduction of the tumor without recurrence for 4 years. This report demonstrates that a solitary primary intracranial melanoma without leptomeningeal dissemination and with rare mitoses may yield a good result with chemotherapy.

Changes in Cerebral Blood Flow after Carotid Endarterectomy

We evaluated changes in cerebral blood flow (CBF) after carotid endarterectomy (CEA) in patients with internal carotid (ICA) stenosis. We studied 46 patients with ICA stenosis who underwent CEA. The mean age of the patients was 63 years, and their mean ICA stenosis was 73%. CBF in the middle cerebral artery territory was measured with xenon-enhanced CT tomography (Xe-CT) before and 3 weeks after CEA. In addition, cerebrovascular reactivity (CVR) was measured after intravenous administration of acetazolamide (ACZ) in 16 patients. There was no significant relationship between the degree of stenosis and CBF. Ten patients had decreased CBF before CEA, and CBF improved in nine of these after CEA. The CVR in 6 of 7 patients with impaired CVR before CEA improved to varying degrees after CEA. The CBF in patients with ICA stenosis varied according to the degree of collateral circulation. In conclusion, CEA can increase CBF and improve CVR in patients with low CBF or low CVR by restoring blood flow through the ICA.

Acute brain swelling in cerebral embolization model of rats I: Epidural pressure monitoring

The authors measured epidural pressure of rats using a microballoon to monitor brain swelling after cerebral embolism. Rats with embolization of the major cerebral artery frequently demonstrated acute brain swelling. Within 5 hours of embolization, the increase in epidural pressure was 29.7 +/- 20.3 mm Hg (mean +/- SD), ranging from 3 to 68 mm Hg. The increase in epidural pressure tended to reach a near-maximal value within 30 minutes of embolization and thereafter stayed at that point until the end of the experiment. These results suggest that measuring epidural pressure can quantitatively assess acute brain swelling in rats.

Outcome of Patients with Severe Head Injury — Evaluation by Cerebral Perfusion Pressure

The outcome of patients sustaining head injury is affected by many factors: type of injury (diffuse or focal), coma level, age, intracranial pressure (ICP), cerebral perfusion pressure (CPP) and so on [1]. Of these factors, CPP is considered to be the most important because much of secondary brain insults are caused by ischemia through the reduction in CPP. One purpose of this study was to clarify the influence of CPP on the outcome of severely head injured patients. Another was to examine the effect of barbiturate therapy upon the outcome.

Diffusion Anisotropy of Cerebral Ischemia

Focal cerebral ischemia was produced by occlusion of the middle cerebral artery with a silicone cylinder in Wistar rats. Diffusion-weighted echo-planar images (DW-EPIs) using the motion-probing gradient (MPG) method were acquired at 1-3 hours and 24-48 hours after occlusion. Apparent diffusion coefficients (ADCs) were calculated from these images in ischemic lesions and in normal unoccluded regions. Results were as follows. 1. Ischemic lesions could be detected on the DW-EPIs at 1 hour after occlusion. 2. The ADC of water in the brain tissue was smaller than that of free water as a result of restricted diffusion. 3. Anisotropic diffusion that probably can be attributed to the myelin sheath was observed in the normal deep white matter. 4. In the ischemic lesions, the ADC decreased rapidly within 1-3 hours after occlusion and then slightly further declined after 24-48 hours. In the ischemic deep white matter, diffusion anisotropy disappeared at 24-48 hours after occlusion. Diffusion-weighted imaging may have applications in the examination of pathophysiological mechanisms in cerebral ischemia by means of evaluation of ADC and diffusion anisotropy.