Mitsugu Nakamura

Two unusual cases of multiple dural arteriovenous fistulas

OBJECTIVE AND IMPORTANCE Two patients with dural arteriovenous fistulas involving the transverse sinus and superior sagittal sinus are described, with a focus on the unique type of venous drainage of the fistula. CLINICAL PRESENTATION Both patients presented with papilledema and progressive visual disturbance. Angiography and magnetic resonance imaging showed that the fistulas involving the superior sagittal sinus had a dilated venous channel, separate from the sinus lumen, located within the wall of the sinus. INTERVENTION Transvenous embolization of the venous channel of the fistula, proximal to its drainage into the superior sagittal sinus, resulted in closure of the fistula and restoration of the superior sagittal sinus function. The clinical symptoms were reversed; the symptoms are believed to have reflected venous hypertension in the superior sagittal sinus, resulting from the shunted flow and interfering with normal venous drainage. CONCLUSION This unique type of dural arteriovenous fistula may be a variant, occurring in the developmental process of the fistula. It is significant clinically because transvenous embolization can be used to close the fistula and restore sinus function.

Intradural Spinal Lipomas Not Associated with Spinal Dysraphism: A Report of Four Cases

Intradural spinal lipomas that are not associated with spinal dysraphism are rare. We report four cases of adult patients with intradural spinal lipomas. All of the patients were young adults, three women and one man, who ranged in age from 22 to 37 years (mean, 30.3 yr). The clinical presentation of these lesions varied, depending upon the size and location of each lipoma. It is interesting that the symptoms in the women gradually deteriorated during pregnancy or after delivery. Magnetic resonance imaging was very useful in determining the exact location of lipoma. In three of four patients, neurological improvement was obtained after decompressive laminectomy and partial removal of the lipoma.

A tentorial dural arteriovenous fistula successfully treated with interruption of leptomeningeal venous drainage using microvascular Doppler sonography: case report.

BACKGROUND Complete interruption of a dural arteriovenous fistula (DAVF) has been confirmed intraoperatively by visual inspection and intraoperative angiography. To confirm complete interruption of the shunt flow during the surgical treatment of a tentorial DAVF, we used intraoperative microvascular doppler monitoring. CASE DESCRIPTION A 71-year-old man suffered from severe subarachnoid hemorrhage. Angiography showed a tentorial DAVF with pure leptomeningeal drainage associated with a venous pouch. After the patients neurologic condition had improved, he underwent interruption of the draining vein via a right suboccipital approach. An arterialized drainage vein was easily identified by applying the microvascular doppler probe to the shunting vessels and was completely obliterated by clipping. There were no complications associated with use of the microvascular doppler. The postoperative course was uneventful and follow-up angiography showed complete obliteration of the DAVF. CONCLUSION Intraoperative microvascular doppler monitoring is a useful technique not only for evaluating arterialized leptomeningeal drainage veins but also for confirming the complete obliteration of these vessels.

Syringomyelia Associated with Hajdu-Cheney Syndrome: Case Report

OBJECTIVE AND IMPORTANCE Hajdu-Cheney syndrome is a rare idiopathic bone disease based on a generalized bone dysplasia accompanied by acro-osteolysis. We describe a surgical case of this syndrome that was accompanied by neurological signs associated with cervical syringomyelia. CLINICAL PRESENTATION A 41-year-old woman was referred to our hospital with mild quadriparesis and sensory disturbance resulting from a car accident. There was a neck injury. She showed almost all of the major characteristic clinical features and roentgenographic findings of Hajdu-Cheney syndrome with syringomyelia. INTERVENTION Surgical treatment was indicated because of the progressive neurological deficits. Foramen magnum decompression and C1 laminectomy were performed, and the dura was exposed. The dura was opened at the area of the foramen magnum and C1. The occipitocervical posterior fusion was carried out with an iliac bone graft and titanium wires. CONCLUSION Postoperatively, quadriparesis and sensory disturbance improved and the patient showed improved ambulation. Magnetic resonance imaging disclosed the well-decompressed foramen magnum. The syringomyelia disappeared in the segmental area of C2 and was decreased in the segmental areas of C5-T6. The treatment of this syndrome is symptomatic. In this patient, magnetic resonance imaging disclosed compression of the brain stem by basilar invagination and platybasia, disturbance of cerebrospinal fluid flow at the level of the foramen magnum, and syringomyelia. It was suspected that the obstruction of cerebrospinal fluid flow at the level of foramen magnum caused the cervical syringomyelia. However, the long-term prognosis remains uncertain. Follow-up is necessary to assess the final result of the treatment.

Intradural Spinal Lipomas Not Associated with Spinal Dysraphism

ABSTRACTINTRADURAL SPINAL LIPOMAS that are not associated with spinal dysraphism are rare. We report four cases of adult patients with intradural spinal lipomas. All of the patients were young adults, three women and one man, who ranged in age from 22 to 37 years (mean, 30.3 yr). The clinical presen

Thrombolytic therapy with tissue plasminogen activator for prevention of vasospasm in experimental subarachnoid hemorrhage: Its efficacy and problems

We investigated the efficacy of two different tissue plasminogen activators (t-PA) for preventing vasospasm after experimental subarachnoid hemorrhage (SAH) in rabbits. Intrathecal injection of Silteplase and Alteplase showed significant preventive action against vasospasm following SAH and thrombolytic effect. The low dose groups with both t-PA showed more preventive action on day 1 than the high dose groups. The data suggest that the determination of optimum dose of t-PA is essential in clinical use of t-PA.

Significance of blood aspiration in carotid artery stenting with Angioguard XP

BACKGROUND AND PURPOSE In some patients, angiographic flow impairment is observed during carotid artery stenting (CAS) using Angioguard XP (AGXP), resulting in neurological symptoms. CAS was thus modified to improve clinical outcome. METHODS Ninety-seven patients were treated with CAS using AGXP from January 2008 to October 2009. In period I (January-December 2008; n = 53), blood aspirations were performed only in no-flow cases. In period II (January-October 2009; n = 44), blood aspirations were performed in no-flow and slow-flow cases. Clinical outcome, detection of microembolic lesions on diffusion-weighted imaging (DWI) and flow impairment during CAS were examined between these two periods before and after modifying the CAS procedure. RESULTS Periprocedural transient ischemic attacks occurred in 10 patients (18.9%) and one patient (2.27%) in periods I and II, respectively (P = .018). Minor and major strokes were observed in two patients in each period (P = .849). New ipsilateral DWI lesions were detected in 25 patients (47.2%) and 11 patients (25.0%) in periods I and II, respectively (P = .024). Among 18 slow-flow cases, new DWI lesions were detected in one patient (9.09%) and five patients (71.4%) with (n = 11) and without (n = 7) blood aspirations, respectively (P = .013). Neurological symptoms were observed only in three of seven patients (42.9%) without aspirations, compared to one of 11 patients (9.1%) with aspirations (P = .043). CONCLUSION Postoperative symptomatic stroke and new DWI lesions are significantly associated with blood flow impairment during CAS using AGXP. When flow impairment occurs, blood aspiration should be performed.

Combined transpetrosal and fronto-orbito-zygomatic approach to a giant skull based meningioma: a case report.

BACKGROUND Recently, various surgical approaches to skull base lesions have been developed. Skillful use of the combination of two standard approaches make possible the removal of large brain lesions, which conventionally had been considered inoperative. In this study, we present a case of a giant meningioma located in the cerebellopontine angle and middle cranial fossa. A near total resection was achieved using a combined transpetrosal and fronto-orbito-zygomatic approach. CASE REPORT A 15-year-old boy presented with a meningioma that caused a left hearing loss, dysarthria, and cerebellar ataxia. Preoperative magnetic resonance imaging revealed a giant meningioma located in the right cerebellopontine angle, middle fossa, and cavernous sinus. The patient underwent a near total resection of the tumor through a combined transpetrosal and fronto-orbito-zygomatic approach. He experienced a marked improvement postoperatively and entered high school the following year. CONCLUSIONS An approach from several angles was necessary for the giant skull based tumor presented here. A combination approach was selected for obtaining a wide operative field with minimal brain compression during resection of neoplasm. According to the individual features of each case, selection of the operative approach, decisions regarding the extent of excision, and postoperative treatment regimens should be adequately planned in the preoperative period.

Image-guided microsurgery with the Mehrkoordinaten Manipulator system for cerebral arteriovenous malformations.

Four patients with cerebral arteriovenous malformations (AVMs) underwent image-guided microsurgery with the Mehrkoordinaten Manipulator (MKM) system, which integrates a robotic microscope with a computer workstation. The patients were all male, from 8 to 51 years old (mean = 24), all presenting with intracerebral haemorrhage. The lesion was located in the deep sylvian fissure in one patient, the fronto-parieto-occipital area in one and the trigone in two. Stereotactic computed tomography and magnetic resource imaging of 1-mm slices were taken. The extent of AVM and the draining vein, predetermined with the MKM workstation, could be superimposed on the microscopic view, resulting in minimum scalp incision and craniotomy, as well as allowing for a stereotactic approach to deep-seated lesions. Superimposition of the contour of the lesion was also useful for resecting the lesion, although intraoperative diagnosis of the total resection required intraoperative digital subtraction angiography. In conclusion, image-guided microsurgery with the MKM system can assist minimally invasive and maximally effective microsurgery for cerebral AVMs.

Endovascular and surgical treatment of a metameric spinal arteriovenous malformation.

Metameric spinal arteriovenous malformations (AVMs) refer to the lesions completely outside of the spinal cord and the surrounding dura. This paper presents an unusual metameric spinal AVM that was fed by multiple radiculomeningeal arteries and was located totally within the extradural space and the vertebral bodies. The metameric spinal AVM has an exclusive epidural venous drainage and presents as a distinct mass from the dural and the intradural spinal AVMs. Total removal of metameric spinal AVMs are sometimes difficult because of wide extension, profound bleeding, and spinal instability after resection. Therefore, the basic management strategy for these lesions is preoperative arterial or venous embolization and resection.