Nobuhiko Aoki

Lumboperitoneal Shunt: Clinical Applications, Complications, and Comparison with Ventriculoperitoneal Shunt

Lumboperitoneal (LP) shunting has the advantage of completely extracranial surgical management, minimizing intracranial complications. An LP shunt has been intentionally adopted for patients who require cerebrospinal fluid diversion. A retrospective study was designed to examine the indications for and complications associated with LP shunts in 207 patients (including 28 pediatric patients) treated during the past 11 years. Follow-up averaging 5.1 years revealed no deaths related directly to LP shunt placement. Twenty-nine patients (14%) underwent revision of the shunt because of obstruction. Shunt-related infections were observed in only 2 patients (1%). Radicular pain occurred in 10 patients (5%), 2 of whom required shunt replacement. Postoperative occurrence of dyspnea and disturbance of consciousness necessitated conversion to a ventriculoperitoneal (VP) shunt in 2 patients (1%), who subsequently were noted to have Chiari malformations. In 4 patients (2%), an acute subdural hematoma developed after mild head trauma. Symptomatic chronic subdural hematomas were observed in 2 patients (1%). One patient had a mild myelopathy that rapidly resolved after shunt replacement. The comparison to 120 patients treated with a VP shunt during the identical period (an average follow-up of 5.2 years) suggests the following conclusions. After subarachnoid hemorrhage caused by a ruptured aneurysm, hydrocephalus is usually of the communicating type and is an indication for an LP shunt. The incidence of infection and malfunction with an LP shunt is significantly lower than that with a VP shunt. An LP shunt is also indicated for pediatric patients, although a relatively higher incidence of malfunction is noted compared to adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Subdural Hematoma with Rapid Resolution in Infancy: Case Report

An infant who suffered acute subdural hematoma due to minor head trauma twice in a short period is presented. Each subdural hematoma, showing high density on computed tomographic scanning, resolved with unusual rapidity, resulting in full recovery after nonsurgical management. The mechanism of this rapid resolution of each hematoma was thought to be participation of cerebrospinal fluid secondary to a tearing of the arachnoid membrane.

Cerebrovascular bypass surgery for the treatment of Moyamoya disease: Unsatisfactory outcome in the patients presenting with intracranial hemorrhage

While the efficacy of cerebrovascular bypass surgery for Moyamoya disease with ischemic events has been substantiated, the surgical indication for the patients presenting with intracranial hemorrhage is as yet undetermined. In an effort to prevent rebleeding from rupture of Moyamoya vessels, seven patients with intracranial hemorrhage underwent indirect bypass surgery. During the follow-up period between 2 and 11 years (mean 4.9 years), one patient suffered rebleeding 5 years after bypass surgery. Follow-up cerebral angiography failed to show revascularization and reduction of moyamoya vessels in all but one of seven patients. Thus, the authors experience suggests that bypass surgery for Moyamoya disease with hemorrhage is angiographically far less successful compared to that with ischemia. A review of the series including patients with angiographically successful revascularization and reduction of Moyamoya vessels failed to demonstrate the definitive effectiveness in eliminating the risk of further intracranial hemorrhage.

Intracranial arteriovenous fistula manifesting as progressive neurological deterioration in an infant : case report

This 1-year-old male infant had been diagnosed with cerebral degenerative disease because he developed psychomotor regression, and brain atrophy was demonstrated on computed tomography. He underwent magnetic resonance imaging, which suggested a cerebrovascular malformation. Cerebral angiography disclosed an arteriovenous fistula, fed by an anterior cerebral artery and directly draining into a cortical vein. The occlusion of the feeding artery was followed by a satisfactory recovery. The mechanism of the neurological symptoms in this patient is thought to be caused by a steal phenomenon and compression of the brain stem by venous engorgement in the posterior fossa.

Zygomatic temporopolar approach for basilar artery aneurysms

For surgery of upper basilar artery aneurysms, we have modified the temporopolar approach proposed by Sano by detaching the zygomatic arch to obtain a wide, shallow operating field. This approach seems to be suitable for anteriorly protruding, high-positioned, or large aneurysms of the upper basilar artery. We have used this zygomatic temporopolar approach in 4 patients with such aneurysms and obtained satisfactory results. In this paper, we detail the operative procedure and emphasize certain technical points to minimize temporal lobe retraction and to prevent oculomotor and facial nerve injuries.

Slit ventricle syndrome after cyst-peritoneal shunting for the treatment of intracranial arachnoid cyst

Serious complications following installation of a cyst-peritoneal shunt in an 8-year-old boy with asymptomatic arachnoid cyst in the middle cranial fossa are reported. Highly elevated intracranial pressure without association of ventriculomegaly seen in this patient indicates slit ventricle syndrome caused by malfunction of the cyst-peritoneal shunt. This phenomenon is worth recognizing as a possible consequence of cyst-peritoneal shunting for the treatment of intracranial arachnoid cyst.

A new therapeutic method for chronic subdural hematoma in adults: Replacement of the hematoma with oxygen via percutaneous subdural tapping

Seeking radical removal of chronic subdural hematoma using a simple and less invasive procedure, the author has devised a new method--replacement of the hematoma with oxygen via percutaneous subdural tapping. In this study, 40 patients were treated with this procedure. All patients made a full recovery after the treatment, without complications related to replacement of the hematoma with oxygen. Follow-up investigation showed recurrence of the lesion in two patients (5%). Because of its simplicity, reduced invasiveness, and short hospitalization, the procedure presented here is acceptable as an optimal therapeutic modality for chronic subdural hematoma in adults. Theoretical considerations supporting the safety of this procedure are discussed.

Intraoperative subdural hematoma in a patient with arachnoid cyst in the middle cranial fossa

A case of arachnoid cyst in the middle cranial fossa complicated by intraoperative subdural hemorrhage is presented. Accumulation of cerebrospinal fluid (CSF) outside the outer wall of the arachnoid cyst was found to induce the rupture of well-developed, fragile leptomeningeal vessels at the base of the middle cranial fossa. This phenomenon is noteworthy as a pitfall in surgery for intracranial arachnoid cyst and suggest the bleeding source of subdural hematoma occasionally associated with this lesion.

Resolution of Hemifacial Spasm after Posterior Fossa Exploration without Vascular Decompression

A 57-year-old woman who had hemifacial spasm on the left side for 5 years underwent exploration of the cerebellopontine angle region for the purpose of microvascular decompression. At operation, however, no artery, vein, or other abnormality was noted at the facial nerve root exit zone. Consequently, the exploration was completed without additional manipulation or the placement of a protective barrier, but the patient awoke from the operation completely free of the spasm. The cause of the hemifacial spasm in this patient could not be explained by the currently predominating vascular compression theory.

Acute epidural hematoma developing during twist-drill craniostomy: a complication of percutaneous subdural tapping for the treatment of chronic subdural hematoma

BACKGROUND This case illustrates that although percutaneous subdural tapping for patients with chronic subdural hematoma (CSDH) is successful and minimally invasive, it can be complicated by acute epidural hematoma. CASE PRESENTATION A 62-year-old woman presented with headache two months after minor head trauma. Computed tomography (CT) scanning revealed CSDH with mixed density on the right side. Prior to percutaneous subdural tapping, twist-drill craniostomy was performed at the parietal tuber. When the drill-needle reached the dura mater, the patient began to complain of headache, which was followed by altered consciousness. CT scanning disclosed acute epidural hematoma abutting the CSDH; both hematomas were evacuated by emergency craniotomy. At surgery, no definite bleeding source was identified apart from oozing on the dura mater. CONCLUSION Hemorrhagic complications after percutaneous subdural tapping are rare. The formation of acute epidural hematoma during twist-drill craniostomy has not been reported in the literature. This complication can occur when the blunt tip of the drill-needle remains on the dura mater without penetrating into the subdural hematoma cavity.