Biomedical subjects

Kiyoshi Kazekawa

Publications and source records attributed to Kiyoshi Kazekawa.

18 recordsLinked to original sources

PubMed2007

[Case of ruptured superior cerebellar artery dissection treated by endovascular embolization].

The authors herein report a case of a ruptured dissection of the superior cerebellar artery (SCA). A 68-year-old man presented with symptons of sudden headache and nausea. The CT scan revealed the presence of both a subarachnoid hemorrhage (SAH) and acute hydrocephalus. The left vertebral angiogram showed an fusiform dilatation in the cerebellomesencephalic segment of the left SCA. Endovascular embolization of the aneurysm and SCA was successfully performed using Guglielmi detachable coils (GDCs). No delayed ischemic deficits were observed after the treatment. A dissection of the distal segment of the SCA is a very rare occurrence. We believe endovascular embolization using GDCs to be an effective and less invasive therapy for the treatment of an SCA dissection with SAH.

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PubMed2006

Stent fracture in revascularization for symptomatic ostial vertebral artery stenosis.

INTRODUCTION: We assessed the long-term follow-up examinations and complications of percutaneous transluminal angioplasty and stenting (PTAS) for symptomatic ostial vertebral artery (VA) stenosis. METHODS: A retrospective study was done to evaluate 12 patients with symptomatic ostial VA stenosis who underwent PTAS. Six patients were treated with the Palmaz stent and six with a balloon-expandable coronary stent. Initial angiographic follow-up examination was conducted about 12 months after PTAS in all patients. Simple radiographic, ultrasonographic and clinical follow-up examinations were scheduled every 6 months. RESULTS: Excellent dilatation was achieved in all patients without any procedural complications. Initial angiographic follow-up obtained at a mean of 13 months after PTAS detected no restenosis. However, an asymptomatic severe restenosis was detected at 24 months after PTAS in one patient (8%). During a mean follow-up of 31.5 months, three stent fractures were detected in deployed coronary stents (50%). None of the stent fractures was associated with either recurrent stroke or restenosis. No patients developed recurrent symptoms during the follow-up period. CONCLUSION: PTAS for symptomatic ostial VA stenosis is effective in preventing recurrent stroke. As the open-cell single-joint type of stent is associated with the risk of fracture, long-term follow-up examinations including simple radiography are needed.

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PubMed2006

Percutaneous reconstruction of the innominate bifurcation using the retrograde 'kissing stents' technique.

INTRODUCTION: Obstructions of the supraaortic vessels are an important cause of morbidity associated with a variety of symptoms. Percutaneous transluminal angioplasty has evolved as an effective and safe treatment modality for occlusive lesions of the supraaortic vessels. However, the endovascular management of an innominate bifurcation has not previously been reported. METHODS: A 53-year-old female with a history of systematic hypertension, diabetes mellitus and hypercholesterolemia presented with left hemiparesis and dysarthria. Angiography of the innominate artery showed a stenosis of the innominate bifurcation. RESULTS: The lesion was successfully treated using the retrograde kissing stent technique via a brachial approach and an exposed direct carotid approach. CONCLUSION: The retrograde kissing stent technique for the treatment of a stenosis of the innominate bifurcation was found to be a safe and effective alternative to conventional surgery.

Angiography↗

PubMed2006

Hyperform remodeling balloon for the balloon occlusion test of persistent primitive trigeminal artery aneurysm - case report.

A 17-year-old woman presented with a rare aneurysm at the junction of the persistent primitive trigeminal artery (PPTA) and the internal carotid artery (ICA) manifesting as left abducens nerve paresis. The aneurysm and the ICA were both successfully occluded with coils. The balloon occlusion test used the HyperForm balloon microcatheter to seal the PPTA and ICA, which is very important to determine the optimal treatment strategy for a PPTA aneurysm.

Abducens Nerve Diseases↗

PubMed2005

Hemodynamic stability under general anesthesia in carotid artery stenting.

PURPOSE: The purpose of our study was to investigate the frequency of hemodynamic instability in patients undergoing carotid artery stenting (CAS) under general anesthesia using sevoflurane and nitrous oxide in oxygen. METHODS: A total of 97 consecutive CAS procedures were performed in 84 patients under sevoflurane anesthesia. The following hemodynamic variables were assessed: degree of systolic blood pressure change (deltaSBP) during CAS, hypotension, and bradycardia during and after CAS. RESULTS: During CAS, hypotension occurred in 43% of the patients, and bradycardia occurred in 14%. There was individual variation in the deltaSBP during CAS. Systolic blood pressure (SBP) change >50 mmHg was not seen in this series. After CAS, hypotension occurred in 24%, and bradycardia occurred in 10%. Cerebral infarction occurred in three cases. The stroke rate was 3.1% in this series. CONCLUSION: General anesthesia using sevoflurane and nitrous oxide in oxygen depressed barorecepter reflex sensitivity, induced hemodynamic stability under CAS, and may decrease the rate of occurrence of complications.

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PubMed2003

Effect on cerebral vasospasm of coil embolization followed by microcatheter intrathecal urokinase infusion into the cisterna magna: a prospective randomized study.

BACKGROUND AND PURPOSE: Vasospasm remains the leading cause of death and permanent neurological disability in patients with aneurysmal subarachnoid hemorrhage (SAH). The objective of our prospective randomized trial of coil embolization followed by intrathecal urokinase infusion into the cisterna magna (ITUKI therapy) was to test its effectiveness in preventing or alleviating the severity of ischemic neurological deficits caused by vasospasm. METHODS: We enrolled 110 patients with ruptured intracranial aneurysms eligible for coil embolization and randomly assigned them to embolization with (n=57) or without (n=53) ITUKI therapy performed within 24 hours of aneurysmal SAH. The incidence of symptomatic vasospasms and the clinical outcomes, based on the Glasgow Outcome Scale, 6 months after SAH onset were assessed. RESULTS: There were no side effects or adverse reactions attributable to ITUKI therapy. Symptomatic vasospasm occurred in 5 patients (8.8%) with and 16 (30.2%) without ITUKI therapy; the difference was significant (P=0.012). Although the mortality rate did not differ between the groups, patients with ITUKI therapy had significantly better outcomes than those without (P=0.036). CONCLUSIONS: Our results demonstrate that ITUKI therapy significantly reduced the occurrence of symptomatic vasospasm. Although it did not completely prevent vasospasms, ITUKI therapy resulted in a lower rate of permanent neurological deficits.

Adult↗

PubMed2003

Improved cerebral perfusion after simultaneous stenting for tandem stenoses of the internal carotid artery--two case reports.

Two patients with extracranial internal carotid artery (ICA) stenosis and tandem stenosis of the ipsilateral intracranial ICA were treated simultaneously by angioplasty with stenting. A 68-year-old man who presented with neovascular glaucoma had 90% stenosis of the right cervical ICA and 80% stenosis of the ipsilateral petrous ICA. A 74-year-old man who suffered from transient ischemic attack had 75% stenosis of the left cervical ICA and 90% stenosis of the ipsilateral cavernous ICA. Hemodynamic compromise was confirmed in both patients. Tandem stenting of both extracranial and intracranial ICA stenoses was performed simultaneously in both patients without complications. Poststenting angiography demonstrated excellent dilation of both lesions and normalization of cerebral perfusion. Simultaneous tandem stenting for extracranial ICA stenosis with intracranial tandem stenosis is less invasive than open surgery in high-risk patients with hemodynamic compromise, especially if the major lesion responsible for cerebral hypoperfusion is difficult to determine.

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PubMed2003

Retrograde carotid stenting for isolated stenosis of the proximal common carotid artery--case report.

A 49-year-old female with a history of systemic hypertension and diabetes mellitus suffered transient right hemiparesis. Carotid angiography with arch-aortography detected severe stenosis of the proximal portion of the left common carotid artery. The left carotid bifurcation was surgically exposed and retrograde catheterization was performed to approach the proximal common carotid artery stenosis. The lesion was dilated with a balloon catheter and successfully stented without complications. The left internal carotid artery was clamped during the procedure to avoid embolism. Retrograde carotid stenting for stenosis of the proximal common carotid artery is a safe and effective alternative to conventional surgery in selected patients.

Angioplasty, Balloon↗

PubMed2002

Traumatic middle meningeal artery pseudoaneurysm and subsequent fistula formation with the cavernous sinus: case report.

BACKGROUND: A combination of pseudoaneurysm and arteriovenous fistula of the middle meningeal artery is rare. We describe a case of traumatic pseudoaneurysm of the middle meningeal artery, which subsequently formed a fistula with the cavernous sinus. CASE DESCRIPTION: A 23-year-old man suffered from blunt head trauma and skull fractures. Sixteen days later, he suddenly experienced headache and a bruit was auscultated over the left ear. Three-dimensional computed tomographic angiography revealed dilatation of the left middle meningeal artery. The dilation proved to be a pseudoaneurysm on cerebral angiograms and it was also found to have formed a fistula with the cavernous sinus. Both lesions were successfully obliterated by endovascular embolization using microcoils. CONCLUSION: Head injury may lead to asymptomatic pseudoaneurysm or dural arteriovenous fistula. Neurosurgeons should always bear in mind the possibility of such vascular injuries after blunt head trauma to prevent any hemorrhagic complications.

Adult↗

PubMed2002

Rapid expansion of benign scalp neurofibroma caused by massive intratumoral hemorrhage--case report.

A 62-year-old man with neurofibromatosis type 1 presented with rapid growth of a scalp mass. Head computed tomography demonstrated a large extracranial tumor of soft tissue density with massive intratumoral hematoma. Cerebral angiography demonstrated remarkable hypervascularity of the tumor. Preoperative embolization and total removal of the tumor was performed. The tumor contained a large amount of intratumoral hematoma (500 ml). The histological diagnosis was neurofibroma without malignant transformation. Benign scalp neurofibroma showing massive intratumoral hemorrhage is rare. Rapid growth or intratumoral hemorrhage in neurofibroma may be an indicator of malignant transformation.

Hemorrhage↗

PubMed2002

Aberrant right subclavian artery--three case reports.

Conventional angiography detected three cases of aberrant right subclavian artery. A 51-year-old female presented with a small infarction in the left medulla oblongata and severe stenosis of the left subclavian artery. A 59-year-old female presented with multiple cerebral infarctions and severe atherosclerotic changes in the intracranial arteries. A 58-year-old female presented with aneurysmal subarachnoid hemorrhage. The aberrant right subclavian artery was asymptomatic in all patients. Knowledge of this anatomical variation is important in diagnostic neuroangiography and interventional neuroradiology.

Aneurysm, Ruptured↗

PubMed2002

A mixture of ethylene vinyl alcohol copolymer and ethanol yielding a nonadhesive liquid embolic agent to treat cerebral arteriovenous malformations: initial clinical experience.

OBJECT: The authors report their clinical experience with their new nonadhesive liquid embolic agent, an ethylene vinyl alcohol copolymer (EVAL)/ethanol mixture, to treat arteriovenous malformations (AVMs). METHODS: Between June 1995 and April 2001, 57 patients with confirmed AVMs underwent embolization of their lesions with the EVAL/ethanol mixture. In 87 procedures consisting of one to three stages, the authors embolized 185 feeding arteries to occlude as much of the AVM as possible. Repeated injections under fluoroscopic control could be performed smoothly without encountering cementing of the catheter to the vessel wall. Among the 87 embolizations undertaken in 57 patients, seven procedures (8%) in six patients produced new postembolization symptoms. Resolution of these symptoms occurred within hours or days after four of the seven procedures; permanent neurological deficits remained after the other three procedures (3.4%). Of the 57 patients, three underwent postembolization radiosurgery, and 54 underwent radical treatment with microsurgical extirpation. Histopathological examination of the 54 specimens disclosed mild inflammation within the embolized lumen without inflammatory reactions in the media or adventitia. Follow-up angiograms obtained 3 years after radiosurgery was administered showed that in all three patients treated in this fashion the nidus had completely disappeared. CONCLUSIONS: The EVAL/ethanol mixture is handled easily and appears to be an effective and safe agent for preoperative embolization of AVMs.

Adolescent↗

PubMed2002

A nonadhesive liquid embolic agent composed of ethylene vinyl alcohol copolymer and ethanol mixture for the treatment of cerebral arteriovenous malformations: experimental study.

OBJECT: The authors have developed a mixture of ethylene vinyl alcohol copolymer (EVAL) and iopamidol, which is dissolved in ethanol, as an alternative solvent to provide a safe means of embolizing arteriovenous malformations (AVMs). METHODS: A two-stage delivery technique is required to prevent premature precipitation in the catheter when using this material: the catheter is first infused with 30% ethanol and this is followed by the delivery of the EVAL-ethanol mixture. Acute angiographic changes were analyzed after superselective delivery of dimethyl sulfoxide (DMSO) and 30% ethanol into the renal artery of rabbits. Histological changes following the embolization of the renal artery achieved using the EVAL-ethanol mixture were recorded at 1 hour and at 2 and 16 weeks after the procedure. Although DMSO always produced severe, rapidly progressive vasospasm in the renal artery during a 1- to 60-minute postinfusion, 30% ethanol did not. Microscopically, the lumens of embolized vessels examined 1 hour after embolization with EVAL-ethanol appeared to be filled with EVAL sponges, leaving almost no open spaces. The space between the EVAL sponges and the inner surface of the vessels was filled with fresh thrombus. In the vessel walls of specimens examined 2 weeks after embolization there was no or a slight inflammatory reaction. Scattered in the EVAL sponges were almost equal numbers of neutrophilic granulocytes and mononuclear cells, indicative of a mild inflammatory response. In specimens examined 16 weeks postembolization, the changes noted at 2 weeks were intensified. There was no definite histopathological evidence of mural hemorrhage, perivascular extravasation of the mixture, or perivascular hemorrhage in any specimen that was examined. CONCLUSIONS: Although the degree of permanence of this embolization material is yet unknown, the mixture was easy to handle, and appeared safe and effective for AVM embolization. Its nonadhesive characteristic and its ability to be infused by repeated injections make it an attractive alternative to currently available materials. The good results obtained in this study led us to undertake a clinical trial, the results of which are contained in a companion article in this issue of the Journal of Neurosurgery.

Animals↗

PubMedDate not supplied

Spontaneous thrombosis of a giant intracavernous internal carotid artery aneurysm and ipsilateral internal carotid artery occlusion.

A 75-year-old man who had suffered from right visual disturbance for 10 years suddenly experienced right cavernous sinus syndrome. Magnetic resonance imaging revealed a giant thrombosed aneurysm in the right cavernous sinus extending to the right middle cranial fossa. Digital subtraction angiography disclosed occlusion of the right internal carotid artery at the petrous portion and good cross filling in the right-sided circulation through the anterior communicating artery. There was no filling of the aneurysm. In this case, the mechanism of parent artery occlusion is unclear, but direct compression and stretching of the parent artery by the aneurysm may be involved.

Aged↗

PubMedDate not supplied

Duplication of distal part of the basilar artery.

We report a case of duplication or fenestration of the distal part of the basilar artery with Shy-Drager syndrome. Duplication and fenestration of the basilar artery are discussed, and a review of embryologic development is presented.

Angiography, Digital Subtraction↗

PubMedDate not supplied

Endovascular treatment of anterior cerebral artery aneurysms using Guglielmi detachable coils: mid-term clinical evaluation.

PURPOSE: Clinical and angiographic evaluations were performed in 19 consecutive patients with anterior communicating artery (ACoA) aneurysms treated by Guglielmi detachable coil (GDC) embolization between March 1997 and April 1999. METHODS: The angiographic criteria for endovascular treatment were 1) small (< 15 mm) aneurysm with a neck smaller than the fundus and 2) distinguishable aneurysm neck and relationship to the parent artery. Initially, we also included patients with anticipated surgical difficulties. These criteria were later expanded to include patients with conditions amenable to surgical clipping. Eleven patients presented with subarachnoid hemorrhage (SAH), and eight patients were asymptomatic. The most recent clinical follow-up was obtained by telephone interview with the patients and with their close relatives, to examine post-treatment personality changes. RESULTS: Complete obliteration (68%) or near-complete obliteration (neck remnant) (32%) of the ACoA aneurysm was achieved in all patients. Six-month follow-up angiography performed in 15 patients demonstrated no recurrence of aneurysms. The clinical outcome was good recovery in 15 (80%), moderately disabled in one (5%), vegetative survival in one (5%), and death in two (10%). The patients who had good recovery did not demonstarate significant personality or behavioral change. No late rebleeding had occurred at the time of writing, a minimum of 33 months postoperatively. CONCLUSION: The outcome of endovascular treatment of ACoA aneurysms was satisfactory, especially in post-treatment psychosocial sequelae.

Aged↗

PubMedDate not supplied

Internal carotid aneurysms presenting with mass effect symptoms of cranial nerve dysfunction: efficacy and imitations of endosaccular embolization with GDC.

OBJECTIVE: The authors report a retrospective analysis of their experience in the endosaccular embolization of internal carotid aneurysms which caused mass effect symptoms of cranial nerves (CN) and review the efficacy and limitations of this technique. METHODS: Between April 1997 and August 2002, 12 internal carotid aneurysms that caused mass effect symptoms of CN were treated by endosaccular GDC embolization with parent artery preservation. The locations were the cavernous internal carotid artery (CV) in six patients, carotid-ophthalmic artery (CO) in two patients, and posterior communicating artery (PCo) in four patients. The angiographical size of the aneurysms ranged from 6 to 20 mm, with a mean of 13.3 mm. Duration of symptoms ranged from 0.5 to 120 months, with a mean of 13.7 months. All aneurysms were treated by endosaccular guglielmi detachable coil (GDC) embolization with preservation of the internal carotid artery. RESULTS: Five patients (42%) had complete resolution of symptoms, four (33%) had significant improvement of symptoms, and three (25%) were unchanged. Immediate posttreatment angiographic studies revealed neck remnant (NR) in nine patients and dome filling (DF) in three patients. In one patient (case 10), the resolved symptoms became worse 29 months later. Follow-up angiograms were obtained in 10 patients, and recanalization was observed in four of them (40%). Transient thrombotic complication occurred in only one patient. The group with resolution or improvement of symptoms demonstrated a shorter duration of symptoms before GDC treatment (< or = 12 months). CONCLUSION: Even subtotal endosaccular embolization of aneurysms may reduce mass effect symptoms of cranial nerves. However, careful follow-up is needed because subtotal occlusion carries a future risk of growth.

Aged↗

PubMedDate not supplied

Dural AVFs of the cavernous sinus: transvenous embolization using a direct superficial temporal vein approach.

We present an alternative endovascular approach to treat dural anterio-venous fistulas (AVFs) of the cavernous sinus that drain only into the superior ophthalmic vein. Two cases of dural AVFs of the cavernous sinus producing increased intraocular pressure and diminishing visual acuity are reported. The cavernous sinus was accessed via the direct superficial temporal vein approach through the superior ophthalmic vein. Successful embolization was documented radiographically and clinically.

Aged↗