Hajime Touho

Preoperative and Postoperative Evaluation of Cerebral Perfusion and Vasodilatory Capacity With 99mTc-HMPAO SPECT and Acetazolamide in Childhood Moyamoya Disease

BACKGROUND AND PURPOSE The results of long-term follow-up studies of cerebral perfusion and vasodilatory capacity following administration of acetazolamide after serial vascular reconstructions in 25 patients with childhood moyamoya disease are reported. METHODS Cerebral perfusion was measured with 99mTc-hexamethylpropyleneamine oxime single-photon emission CT before and after IV administration of 10 mg/kg acetazolamide, which was performed both before and after vascular reconstruction by superficial temporal artery-middle cerebral artery anastomosis and encephalomyosynangiosis (first and second operations) and/or omental transplantation to the brain (third operation). RESULTS Follow-up periods ranged between 12 and 24 months (mean +/- SD, 18.5 +/- 3.2 months) after the first operation. Repetitive transient ischemic attacks disappeared completely after serial vascular reconstructions in all patients. Before the first operation, cerebral perfusion in the territory of the middle cerebral artery on the side of initial operation was 83.9 +/- 4.7% and was significantly lower than that in the contralateral side (88.3 +/- 4.9%, n = 25; P < .0001, paired t test). Vasodilatory capacity on the side of the first operation was -18.4 +/- 2.5% and that on the contralateral side -14.4 +/- 2.1%. The former value was significantly lower than the latter value (n = 25; P < .0001, paired t test). After the first operation, cerebral perfusion and vasodilatory capacity on the side of initial operation were markedly improved, to 87.8 +/- 4.5% and -14.7 +/- 2.7%, respectively (n = 25; P < .0001, both cases, paired t test). Before the second operation, cerebral perfusion and vasodilatory capacity on the side of the second operation were 76.6 +/- 4.1% and -20.1 +/- 1.9%, respectively, and significantly lower than those before the first operation (n = 25; P < .0001, both cases, paired t test). Eight patients subsequently required bifrontal omental transplantation for repetitive paraparetic transient ischemic attacks after the second operation; they had low cerebral perfusion and vasodilatory capacity bilaterally in the territories of the anterior cerebral arteries (72.4 +/- 2.7% and -18.6 +/- 1.7%, respectively). After omental transplantation, both were significantly increased, to 81.9 +/- 3.4% and -11.8 +/- 1.9%, respectively (n = 25; P < .0001, both cases, paired t test). CONCLUSIONS Hemodynamic compromise existed in patients with childhood moyamoya disease and was a major cause of development of ischemic symptoms. Regions in which hemodynamic compromise was present could be determined by measuring regional cerebral perfusion and vasodilatory capacity.

Neurogenic pulmonary edema in the acute stage of hemorrhagic cerebrovascular disease.

Extravascular lung water (EVLW) was measured by the double-indicator dilution method in 25 patients with hemorrhagic cerebrovascular diseases. EVLW had a significantly positive correlation with both alveolar-arterial oxygen difference (AaDO2) and intrapulmonary shunt. The value of EVLW in the acute stage in 15 patients with increased AaDO2 more than 20 mm Hg was 7.8 +/- 2.2 ml/kg and that in the chronic stage 4 weeks after onset significantly decreased to 4.6 +/- 0.7 ml/kg (P less than 0.001). The value of EVLW in the acute stage in 10 patients with normal AaDO2 less than 20 mm Hg was 4.7 +/- 1.1 ml/kg and that in the chronic stage 4 weeks after onset was 4.5 +/- 0.2 ml/kg. There was no significant difference between them. Pulmonary arterial blood pressure, pulmonary capillary wedge pressure, central venous pressure, cardiac index, systemic vascular resistance index, and pulmonary vascular resistance index in the acute stage in the 25 patients were all within the normal range. Three patients with neurogenic pulmonary edema had markedly increased EVLW without abnormalities in pulmonary arterial blood pressure, pulmonary capillary wedge pressure, central venous pressure, cardiac index, systemic vascular resistance index, and pulmonary vascular resistance index. From these facts, the main cause of the increase in EVLW cannot be explained by left ventricular failure, but can be explained by high permeability pulmonary edema.

Surgical reconstruction of failed indirect anastomosis in childhood Moyamoya disease.

Thirty-one patients with moyamoya disease, who had been treated for encephaloduroarteriosynangiosis (EDAS), encephalomyosynangiosis (EMS) or EMS with encephaloarteriosynangiosis (EAS) in other hospitals, were admitted to Osaka Neurological Institute from January 1985 to September 1991. Twenty-seven of 57 sides treated by indirect anastomosis showed good filling of the middle cerebral artery (MCA) territory via the anastomosis, whereas 16 and 14 showed fair and poor collaterals via the anastomosis, respectively. Twenty-eight cerebral hemispheres treated by indirect anastomosis underwent further surgery and received superficial temporal artery-MCA anastomosis with or without EMS for still-existent recurrent transient ischemic attacks or completed stroke even after the indirect anastomosis. One patient still had recurrent transient ischemic attacks with quadriparesis after bilateral encephaloduroarteriosynangiosis, which had produced no effective collaterals in the MCA territory; the patient then underwent omental transplantation to the bilateral anterior cerebral artery and MCA territories, resulting in the cessation of the transient ischemic attacks. Clinical improvement after superficial temporal artery-MCA anastomosis with or without EMS was noted in all patients, except on one side, where a completed stroke had resulted in fixed neurological deficits. We do not know the reasons for the uncertainty of the development of collaterals via the indirect anastomosis, but there are many patients who still need direct reconstruction of the indirect anastomosis.

Intravascular treatment of spinal arteriovenous malformations using a microcatheter—With special reference to serial xylocaine tests and intravascular pressure monitoring

Spinal arteriovenous malformations (spinal AVMs) are now treated using microcatheters and various embolic materials. Interventional techniques of this type are thought to be the first choice for treatment of spinal AVMs. In this study, we used the Tracker vascular access system and MAGIC catheter for intravascular treatment of spinal AVMs in order to avoid proximal occlusion. Notably, serial provocation tests using xylocaine (20 mg in bolus) and intermittent intravascular pressure monitoring in the anterior spinal artery were conducted during embolizations of five intramedullary AVMs. We used 150-350 microns polyvinyl alcohol particles (Ivalon) and/or polyvinyl alcohol (PVA) solutions as embolic materials for occlusion of these AVMs. Vital signs and neurologic functions were carefully monitored during and after the procedure. We were able totally to obliterate the nidus or markedly to reduce its size while preserving the anterior spinal artery in each of the patients. The xylocaine test was conducted an average of 2.6 times (2-4 times) during embolization. For the two patients who were treated with Ivalon and PVA solutions, the final provocation test became positive, and the embolization procedure was terminated. On the other hand, the remaining patients had a positive result on first xylocaine test and were treated with Ivalon alone. At the same time, intravascular pressure monitoring was performed via the microcatheter, which was located in the anterior spinal artery. The value of the intravascular systolic pressure prior to embolization was 71.6 +/- 14.1 mm Hg and it gradually increased during the procedure, and reached 99.6 +/- 12.6 mm Hg (90% of the systemic systolic blood pressure) by the conclusion of embolization. Serial xylocaine tests and intravascular pressure monitoring may be useful for the treatment of spinal AVMs fed mainly by the anterior spinal artery, and embolization with liquid embolic material should be terminated when the provocation test becomes positive and intravascular pressure increased to 90% of the systemic blood pressure.

Falx meningioma presenting as acute subdural hematoma: case report

BACKGROUND Acute subdural hematomas caused by meningiomas have been rarely encountered. Pathophysiologic mechanisms and clinical considerations in these patients have not been sufficiently explored. We addressed the possible mechanism of spontaneous hemorrhage in our case and briefly discuss the optimal treatment. CASE DESCRIPTION This case of falx meningioma presenting as an acute subdural hematoma in a 78-year-old woman is described. On initial computed tomography (CT), an enhancing tumor of the falx appeared to be the cause of hemorrhage. Only faint contrast staining in the periphery of the tumor was seen on right external carotid arteriograms, with no evidence of other vascular supply. Extravasation of contrast material during the procedure occurred suddenly and was successfully treated by endovascular embolization using a microcatheter. The hematoma was emergently evacuated with gross total removal of the tumor. Pathologic examination confirmed a transitional meningioma with abundant hyalinized structures. Disruption of a thin-walled vessel adjacent to the tumor capsule was assumed to be the site of hemorrhage. CONCLUSIONS The longstanding ischemia of the tumor was considered to have produced the deposition of hyalin in the tissue, which changed the hemodynamics within the tumor, producing vascular stress leading to rupture. The prognosis of patients with meningiomas complicated by acute subdural hematoma is generally poor, with mortality reported in approximately one-half of such patients. Surgical exploration is the most effective treatment and should be conducted before irreversible brain damage has occurred.

Evaluation of time-dependent thresholds of cerebral blood flow and transit time during the acute stage of cerebral embolism: a retrospective study.

BACKGROUND Neurons within the ischemic penumbra are thought to be in a potentially reversible state of ischemic challenge. One therapeutic approach that is being actively explored is the recovery of function of cells within the ischemic penumbra through endovascular recanalization of cerebral arteries occluded with embolus. The purpose of this study was to determine the time-dependent hemodynamic threshold for the prevention of irreversible ischemia in patients with acutely symptomatic internal and middle cerebral artery (MCA) embolism. METHODS Thirty-six patients admitted within 6 hours of the onset of symptoms of acute cerebral ischemia, due to embolic occlusion of the major trunk of one of the arteries of the anterior cerebral circulation, were studied. On admission, both cerebral blood flow (CBF) and mean transit time (MTT) measurements were obtained following plain computed tomography (CT). All patients were treated by intraarterial administration of urokinase. MTT in the territory of the affected MCA divided by that in the territory of the unaffected MCA was defined as %MTT. RESULTS A significant negative correlation was found between MTT and CBF. In patients with at least 19 mL/100 g/minute CBF and a maximum of 1.6 %MTT, no cortical infarction occurred whether or not recanalization was obtained. Cortical infarction did not appear in patients with 9 mL/100 g/minute residual CBF and infinite %MTT in whom recanalization was achieved within 2 hours of onset, in patients with 13 mL/100 g/minute residual CBF and 3.7 %MTT in whom recanalization was achieved within 2.5 hours of onset, and in patients with 14 mL/100 g/minute residual CBF and 2.8 %MTT in whom recanalization could be achieved within 3.5 hours of onset. CONCLUSIONS CBF and MTT thresholds for conversion of reversible to irreversible ischemia can be rapidly determined by CT-based technologies. This type of information should be clinically relevant to guiding the management of patients with cerebral embolism.

Superselective embolization of spinal arteriovenous malformations using the Tracker catheter.

Eighteen patients with spinal arteriovenous malformations had been treated with conventional embolization, surgical removal, feeder ligation, and/or feeder coagulation between February 1985 and March 1990. The lesions included six glomus, four juvenile, three extramedullary, and five dural arteriovenous malformations or fistulas. Embolic therapy was conducted in 14 patients by introducing the tip of a catheter into the segmental arteries and injecting polyvinyl alcohol strips (500-1000 microns) (conventional embolization). Follow-up spinal angiography disclosed recanalization in 10 patients (71.4%) and the appearance of new feeding arteries in five patients (35.7%). We introduced the Tracker vascular access system in April 1990. Eight patients (four glomus, one juvenile, and three dural arteriovenous malformations) were treated with the minicatheter and Ivalon particles (150-350 microns). Five patients showed neurological improvement immediately after treatment. The other three patients had severe paraparesis before treatment and did not show any improvement. One patient with a glomus-type arteriovenous malformation showed transient neurological deterioration just after embolization with the Tracker-10 to occlude a lesion fed by the posterior spinal artery, because the Ivalon particles migrated into the anterior spinal artery via the anterior spinal canal artery. In one patient with a juvenile arteriovenous malformation, the Tracker-18 catheter perforated the radiculomedullary artery originating from the right vertebral artery, and subarachnoid hemorrhage occurred. However, the Tracker-10 could later successfully occlude the arteriovenous malformation. The rates of recanalization and appearance of the new feeding vessels were 4/8 (50.0%) and 2/8 (25%), respectively.

Omental transplantation using a superficial temporal artery previously used for encephaloduroarteriosynangiosis.

BACKGROUND Childhood moyamoya disease is a chronically progressive cerebrovascular occlusive disease affecting the territories of the anterior, middle, and posterior cerebral arteries. Surgery used in treatment of moyamoya disease to vascularize the brain include direct and indirect anastomoses. METHODS Intracranial omental transplantation (OMT) was performed using a branch of the superficial temporal artery (STA) that had been used previously for encephaloduroarteriosynangiosis (EDAS) in five children with moyamoya disease. All five children continued to have paraparetic transient ischemic attacks (TIAs), urinary incontinence, and/or progressive mental retardation even after EDAS and/or STA-middle cerebral artery (MCA) anastomosis and encephalomyosynangiosis (EMS) to the territory of the MCA. Previously performed EDAS gave insufficient collaterals to the territory of the MCA in four of the five patients and sufficient collaterals to the territory of the MCA in the remaining patient. OMT was performed after stripping of a branch of the STA used in EDAS that gave insufficient collaterals to the brain in the former four patients; and the latter patient was performed using a parietal branch of the STA distal to the distal burr hole drilled in the previous EDAS. RESULTS OMT resulted in marked improvement in neurologic conditions in all five patients. Four of the five patients suffered no TIAs postoperatively, while the remaining patient still had TIAs but at a markedly decreased frequency. CONCLUSIONS In summary, OMT using a branch of the STA used in previously performed EDAS is required for patients with moyamoya disease who continue to manifest paraparesis, urinary incontinence, and/or progressive mental retardation even after multiple EDAS.

Cortical blood flow response to hypercapnia during anaesthesia in Moyamoya disease

Cortical blood flow (CoBF) was measured continuously by the laser-Doppler method to evaluate the effect of hypercapnia on cortical blood flow during ten surgical procedures in ten young patients (mean ± SD 9.3 ± 6.4 yr) with Moyamoya disease. The CoBF was 42.8 ± 13.4 (ml·100 g−1. min−1) during normocapnia (PaCO2 = 39.0 ± 2.4 mmHg), and 38.7 ± 14.4 during hypercapnia (PaCO2 = 47.1 ± 2.5 mmHg). There was a decrease in CoBF with hypercapnia (P < 0.05) so that the normal CoBF response to hypercapnia was impaired during surgery in the patients with Moyamoya disease. He concluded that patients with Moyamoya disease have a precarious cerebral circulation and hypercapnia may be detrimental to the cortical circulation. This suggests that normocapnia is preferable to hypercapnia in patients with Moyamoya disease during anaesthesia.RésuméPendant dix interventions chirurgicales pratiquées chez dix jeunes patients (âge moyen 9,3 ± 6,4 ans) souffrant de la maladie de Moyamoya, le débit sanguin cortical (DSCo) est mesuré continuellement par la méthode Laser-Doppler dans le but d’évaluer les effets de l’hypercapnie sur le débit sanguin cortical. Le DSCo (ml·100 g−1· min−1) est de 42,8 ± 13,4 pendant la normocapnie (PaCO2 = 39,0 ± 2,4 mmHg) et de 38,7 ± 14,4 pendant l’hypercapnie (PaCO2 = 47,1 ± 2,5 mmHg). La baisse du débit pendant hypercapnie est significative (P < 0,05). Ce qui démontre que la réponse du débit sanguin cérébral est perturbée pendant la chirurgie de la maladie de Moyamoya. On conclut que cette maladie a une influence néfaste sur la circulation cérébrale pendant l’hypercapnie. Ceci suggère que dans la maladie de Moyamoya, la normocapnie est préférable à l’hypercapnie.

Intrahepatic migration of a peritoneal shunt catheter: case report.

The intrahepatic migration of a peritoneal shunt tube of a ventriculoperitoneal shunt system (low pressure Pudenz valve and low pressure Pudenz peritoneal catheter) is reported. This is a rare complication of ventriculoperitoneal shunting and was diagnosed by metrizamide shuntography and abdominal computed tomography. To our knowledge, this is the second case complicated with migration of a peritoneal shunt tube into the liver.