Biomedical subjects

Hitoshi Kobata

Publications and source records attributed to Hitoshi Kobata.

4 recordsLinked to original sources

PubMed2006

Covered stent treatment for traumatic cervical carotid artery aneurysms--two case reports.

A 37-year-old man and a 23-year-old man with cervical carotid artery aneurysms were treated with covered stents. The covered stent was constructed from a Palmaz stent covered with an expanded polytetrafluoroethylene graft. Angiography showed the aneurysms had disappeared immediately after the procedure. Patency of the covered stents was confirmed at 18 and 34 months after intervention by three-dimensional computed tomography angiography. The covered stent allows relatively noninvasive reconstruction of the parent artery that immediately brings about complete thrombosis of the aneurysm. However, delivering the covered stent to the carotid artery may be difficult.

Adult↗

PubMed2005

Regional cerebral blood flow after acetazolamide challenge in patients with dural arteriovenous fistula: simple way to evaluate intracranial venous hypertension.

BACKGROUND AND PURPOSE: Because venous hypertension determines the clinical severity of dural arteriovenous fistulas (DAVFs), evaluation of intracranial venous pressure is important in making decisions concerning treatment. We determined whether intracranial venous hypertension could be quantified by using an acetazolamide test in a manner that indicates whether treatment of the DAVF is necessary. METHODS: We enrolled 21 untreated patients: 11 with a sigmoid and/or transverse DAVF, six with a cavernous DAVF, two with an anterior cranial fossa DAVF, and two with a superior sagittal sinus DAVF. Cerebral hemodynamics were studied with stable-xenon CT. Patients were angiographically classified into three groups, and regional cerebral blood flow (rCBF) after acetazolamide challenge was compared between angiographic groups, between patients with and those without symptoms attributable to intracranial venous hypertension, and between preembolization and postembolization examinations. RESULTS: A high angiographic grade was associated with decreased resting rCBF and a blunted response to acetazolamide. Response to acetazolamide was more sensitive to venous hypertension, as angiographically assessed, than decreased resting rCBF. Resting rCBF and the increase in rCBF associated with acetazolamide were significantly lower in the symptomatic group than in the asymptomatic group. Treatment of the DAVF significantly enhanced the increased rCBF due to the acetazolamide challenge. CONCLUSION: Cerebral venous hypertension in DAVF reduced the response to acetazolamide, as shown on stable-Xe CT. Therefore, a patient with DAVF and a reduced rCBF response to acetazolamide requires treatment irrespective of his or her symptoms.

Acetazolamide↗

PubMed2004

[Superior sagittal sinus occlusion caused by a compound depressed skull fracture: a case treated by emergency surgery].

Depressed skull fractures compressing major venous sinuses are rare, and the treatment is a matter of controversy. The majority of depressed fractures are treated conservatively for fear of bleeding from venous sinuses, but surgical intervention was conducted in a few cases. We report a case of a 59-year-old man with a compound depressed fracture occluding the superior sagittal sinus (SSS). The patient was struck on the head by a heavy iron bar and admitted to our emergency center because of deterioration of consciousness. A computed tomographic scan showed depressed skull fracture overlying the SSS with hemorrhagic lesions in the bilateral parietal lobes and an acute epidural hematoma at the right temporoparietal convexity. Digital subtraction angiography (DSA) showed an occlusion of the SSS and compensatory venous drainage associated with poor capillary filling in the left parietal lobe. On an emergency basis, bone fragments compressing the SSS were surgically removed piece-by-piece to resolve severe venous congestion and to avoid infection. A small tear in the SSS was treated by head elevation and compressing the SSS with Gelfoam. Postoperative DSA confirmed the patency of the SSS and normal blood flow in the left parietal lobe. The patient exhibited slight disorientation and was transferred to another hospital for further rehabilitation. Because of symptomatic severe venous congestion, we had to perform emergency surgical decompression and removal of bone fragments. Treatment strategy for depressed skull fracture with SSS involvement was discussed with review of the literature.

Decompression, Surgical↗

PubMed2002

Cerebellopontine angle epidermoids presenting with cranial nerve hyperactive dysfunction: pathogenesis and long-term surgical results in 30 patients.

OBJECTIVE: To provide the characteristics and long-term surgical results of patients who present with cerebellopontine angle epidermoids and trigeminal neuralgia (TN) or hemifacial spasm. METHODS: A total of 30 patients (23 women, 7 men) who presented with cerebellopontine angle epidermoids and TN (28 patients) or hemifacial spasm (2 patients) between 1982 and 1995 were reviewed, with emphasis being placed on the clinical manifestations, the mechanisms of symptom development, the long-term follow-up results, and the anatomic relationship between the tumor and the surrounding neurovascular structures. RESULTS: The average age of the patients was 37.8 years at symptom onset and 49.3 years at the time of the operation. The tumor-nerve relationships were classified into four types: complete encasement of the nerve by the tumor, compression and distortion of the nerve by the tumor, compression of the nerve by an artery located on the opposite side of the unilateral tumor, and compression of the nerve by an artery on the same side of the tumor. Total resection was achieved in 17 patients (56.7%). Microvascular decompression of the respective cranial nerve was achieved in nine cases of direct arterial compression in addition to tumor removal. The symptom was relieved completely in all cases. In an average follow-up period of 11.5 years, three patients developed recurrent symptoms: two experienced tumor regrowth, and one had arachnoid adhesion. CONCLUSION: Hyperactive dysfunction of the cranial nerves, especially TN, may be the initial and only symptom that patients with cerebellopontine angle epidermoids experience. The occurrence of TN at a younger age was characteristic of TN patients with epidermoids, in contrast to patients with TN due to a vascular cause. The symptom is elicited by compression of the nerve by the tumor per se, by an artery that is displaced to the nerve, or by both. Careful resection of the tumor, whose capsule occasionally is strongly adherent to the neurovascular structures, is necessary, and microvascular decompression to straighten the neuraxis should be performed in some cases to achieve a complete, permanent cure of symptoms with a low rate of recurrence.

Adult↗