Biomedical subjects

H Touho

Publications and source records attributed to H Touho.

At least 37 records · Page 2Linked to original sources

PubMed1995

Hemodynamic evaluation with dynamic DSA during the treatment of cerebral vasospasm: a retrospective study.

BACKGROUND: Percutaneous transluminal angioplasty (PTA) and super-selective intra-arterial infusion of papaverine have recently been performed for the treatment of cerebral arterial vasospasm, with generally favorable results in patients with delayed symptomatic cerebral vasospasm. METHODS: We used dynamic digital subtraction angiography (dynamic DSA) to measure local transit time before and after endovascular treatment (EVT) for the treatment of ruptured intracranial aneurysm and delayed symptomatic cerebral vasospasm. Mean transit time (MTT) was measured by dynamic DSA in 19 patients with ruptured intracranial aneurysm and delayed symptomatic cerebral vasospasm and 6 patients without symptomatic cerebral vasospasm (group III) just after surgery, immediately prior to EVT, just after EVT, and in the chronic stage of disease more than 1 month after onset of subarachnoid hemorrhage. EVT included PTA using a silicone nondetachable balloon and/or superselective infusion of 0.2% papaverine. RESULTS: Symptomatic vasospasm occurred between days 7 and 11 after onset of subarachnoid hemorrhage. The MTT just after the onset of neurologic deterioration in these 10 patients with complete neurologic recovery during the chronic stage of disease (group I) and the other 9 patients without complete recovery (group II) were respectively 6.92 +/- 0.42 seconds and 7.66 +/- 0.78 seconds. The latter value was significantly larger than the former (p < 0.02). MTT just after EVT in group II were also significantly greater than the corresponding MTT in group I (p < 0.002). In addition, immediately prior to EVT the MTT in group I and group II was significantly longer than that in group III (p < 0.0001). CONCLUSIONS: Functional analysis with dynamic DSA can be used to detect hemodynamic disturbances, and can be used for hemodynamic evaluation during the treatment of symptomatic cerebral vasospasm.

Aged↗

PubMed1995

Assessment of delayed cerebral vasospasm using intracisternal echography--technical note.

BACKGROUND: A new technique using intravascular ultrasound has been used for diagnosis of coronary artery in order to obtain intravascular echo images. In this study, an intracisternally positioned ultrasound catheter was introduced obtaining serial echo images of the first segment (MI) of the middle cerebral artery in order to detect cerebral vasospasm following subarachnoid hemorrhage (SAH). METHODS: Thirteen patients were admitted to Osaka Neurological Institute with SAH due to ruptured intracranial aneurysm. All patients underwent surgical neck clipping on the day of admission. In each patient, an 8 Fr. ultrasound imaging catheter (Cardiovascular Imaging Systems, Inc. (CVIS), Sunnyvale, CA) was detained intracisternally adjacent to the M1 segment following neck clipping of the aneurysm and placement of cisternal drainage(s) in the prepontine and/or distal portion of the Sylvian fissure. In order to detain the mirro device near the M1 segment, the tip of a 2.0 cm cisternal drainage tube (SILASCON, E-3L-12, Kaneka Medix Co, Osaka, Japan) was attached to the tip of the intravascular ultrasound catheter with 3-0 silk suture. The tip was placed in the prechiasmal cistern. RESULTS: Angiographic evidence of delayed vasospasm was obtained for three (23.1%) of the 13 patients. In one (33.3%) of the three patients who had angiographic evidence of vasospasm (25% stenosis), decrease in the inner diameter of the M1 segment was detected on the echo images, but in the other two (66.7%), no such decrease was noted on echo images. Angiographically identified vasospasm in the latter patients was associated with only 10% stenosis. CONCLUSIONS: Intracisternally positioned ultrasound catheter can be used for intermittent measurement of the diameter of a target artery for detection of cerebral vasospasm after SAH.

Adult↗

PubMed1995

Percutaneous transluminal angioplasty for severe stenosis of the posterior cerebral artery: case report.

The Stealth dilation catheter was used for the intravascular treatment of a patient who had hemodynamically significant stenosis of the posterior cerebral artery and had a history of recurrent transient ischemic attacks associated with right hemiparesis and ipsilateral hemianopia dating from March 1993. Cerebral perfusion studies prior to and after the intravenous administration of acetazolamide demonstrated regions of moderately low perfusion and low hemodynamic reserve in the territories of the left middle and posterior cerebral arteries. Cerebral angiograms demonstrated severe stenosis of the left posterior cerebral artery and occlusions of both middle cerebral arteries, which had leptomeningeal anastomoses with the posterior cerebral arteries. Percutaneous transluminal angioplasty (PTA) was performed using the Stealth catheter on the stenotic segment of the left posterior cerebral artery after left superficial temporal artery-middle cerebral artery anastomosis. The patient manifested marked improvement in her neurologic condition just after PTA, in association with marked increase in cerebral perfusion and hemodynamic reserve in the territories of the left middle and posterior cerebral arteries. We have presented evidence that PTA can be used to treat patients with stenosis of the first segment of the posterior cerebral artery and hemodynamic compromise in the territory that artery supplies.

Aged↗

PubMed1995

Treatment of type II perimedullary arteriovenous fistulas by intraoperative transvenous embolization: case report.

BACKGROUND Perimedullary arteriovenous fistulas (AVFs) are abnormal vascular connections between medullary arteries and veins without an intervening nidus. It is thought to be difficult to treat Type II AVFs which have multiple feeding branches. We performed intraoperative transvenous embolization to treat Type II AVFs. CASE REPORT A 30-year-old man with Type II perimedullary arteriovenous fistulas (AVFs), present at the level of the L-1 vertebral body, underwent surgical and endovascular treatment. The patient displayed slight motor weakness (4/5) and slight hypesthesia in the right lower extremity. Angiograms demonstrated that an anterior spinal artery and posterior spinal arteries were feeding arteries for the perimedullary AVFs. The patient underwent surgical occlusion of the fistulas three times. Fistulas present on the dorsal surface of the spinal cord were occluded with hemoclips, while those located on the ventral and ventolateral aspect of the spinal cord were occluded transvenously with isobuthyl-2-cyanoacrylate (IBCA) during surgery. Total occlusion of the perimedullary AVFs was achieved with these procedures, and no change was noted postsurgically in the patient's symptoms. CONCLUSIONS In summary, Type II perimedullary AVFs are sometimes difficult to treat using either embolization or open surgery. In such cases, both open surgery and intraoperative transvenous embolization should be performed in order to obtain occlusion of multiple fistulas.

Adult↗

PubMed1995

Intraoperative electrophysiologic monitoring of cranial motor nerves in skull base surgery.

BACKGROUND: Intraoperative cranial nerve monitoring has been applied for the preservation of nerve function during skull base surgery. However, its usefulness is controversial because clinical results reported are limited. METHODS: We evaluated the usefulness of intraoperative electrophysiologic monitoring of the third to seventh cranial motor nerves in 15 patients undergoing skull base surgery. Intracranial bipolar electrical stimulation of each nerve was performed, and compound muscle action potentials (CMAP) were recorded from the innervated muscles. RESULTS: CMAPs were successfully recorded from 23 of the innervated muscles. The loss of the CMAP response during the manipulation of lesions or high stimulus intensity at the end of manipulation seem to be related to the postoperative deficits of nerve function. CONCLUSIONS: The results suggest that intraoperative electrophysiologic monitoring of cranial motor nerves is useful for prediction of postoperative nerve function.

Adult↗

PubMed1995

Cerebral revascularization using gracilis muscle transplantation for childhood moyamoya disease.

BACKGROUND: Omental transplantation is effective in the management of ischemia in the territories of the anterior and posterior cerebral arteries in childhood moyamoya disease. We introduced a surgical revascularization using gracilis muscle transplantation to these territories. METHODS: Between January 1991 and May 1993, six children with moyamoya disease, between the age of 3 and 13 years, underwent gracilis muscle transplantation to the territory of either the anterior or the posterior cerebral artery. The mean period of follow-up after surgery was 15.2 months, with a range of 5 to 32 months. Three of the six patients had suffered from frequent transient visual disturbance and were treated with unilateral or bilateral gracilis muscle transplantation to the territory of the posterior cerebral artery. The other three patients had suffered from frequent transient paraparesis, mental retardation, and/or rectal and urinary incontinence, and were treated with gracilis muscle transplantation bilaterally to the territories of the anterior cerebral arteries. RESULTS: All three patients with gracilis muscle transplantation unilaterally or bilaterally to the occipital lobes manifested complete disappearance of their symptoms. Two of the three patients with gracilis muscle transplantation bilaterally to the frontal lobes also manifested complete disappearance of their symptoms. The remaining patient who underwent the transplantation bilaterally to the frontal lobes, continued to have episodes of transient paraparesis, postsurgically, but the frequency of symptoms was markedly decreased. CONCLUSIONS: Ischemia in the territories of the anterior and/or posterior cerebral arteries could be overcome with the use of gracilis muscle transplantation in childhood moyamoya disease.

Adolescent↗

PubMed1995

Haemodynamic evaluation of paraparetic transient ischaemic attacks in childhood moyamoya disease.

The haemodynamic mechanisms responsible for the appearance of paraparetic transient ischaemic attacks in ten patients with childhood moyamoya disease who subsequently underwent bifrontal omental transplantation were investigated. Cerebral perfusion (CP) was measured with 99mTc-hexamethylene-propyleneamine oxime single photon computed tomography prior to and after administration of acetazolamide. Cerebral perfusion was obtained by dividing radioisotope uptake per pixel in regions of interest by that in cerebellum. Haemodynamic reserve was defined as [CP after acetazolamide--CP before acetazolamide]/CP before acetazolamide x 100. Amounts of CP in the anterior portion of the frontal lobe and in the paracentral lobule were 0.70 +/- 0.04 and 0.74 +/- 0.03, respectively, before appearance of the transient ischaemic attacks. The latter was significantly higher than the former (p < 0.0001). Haemodynamic reserves were -11.1 +/- 2.8 and -9.6 +/- 3.0, respectively, at that time. These two parameters were significantly decreased just after paraparetic transient ischaemic attacks and two parameters in the paracentral lobule were more decreased than those in the anterior portion of the frontal lobe. But these increased again after bifrontal omental transplantation in these two regions. In summary, the watershed region was located anterior to the paracentral lobule before appearance of the transient ischaemic attacks, and widened and moved backward to include the paracentral lobule just before their appearance.

Cerebral Angiography↗

PubMed1995

Hemodynamic evaluation of spinal arteriovenous malformations before and after embolization--preliminary report.

This preliminary study investigated local hemodynamic changes in intramedullary spinal arteriovenous malformation (AVM) before and after embolization. 99mTcO4- was injected into the anterior spinal artery feeding the AVM via a Tracker-10 or MAGIC microcatheter. Time-dependent radioisotope images were sequentially obtained in the anteroposterior plane every 0.2 sec before and just after embolization. Local mean transit time (MTT) was then calculated for both the nidus and draining vein and compared before and after embolization. Prior to embolization, MTTs in the nidus and in the draining vein were 1.84 +/- 0.62 (mean +/- SD) and 2.80 +/- 0.69 sec for the five patients, respectively. MTTs in both the nidus and the draining vein were significantly prolonged after embolization to 3.32 +/- 1.14 and 4.90 +/- 0.93 sec, respectively (p < 0.02 and p < 0.005, respectively). In vivo measurements of local hemodynamic changes in the spinal cord during the treatment of spinal AVMs could be achieved. This method may allow investigation of the hemodynamic mechanisms which induce ischemic symptoms in patients with spinal AVM.

Adult↗

PubMed1995

Endovascular treatment with an ultra-thin 4-French guiding catheter via the transfemoral and transbrachial routes--technical note.

An ultra-thin-walled 4-French catheter was used for angiography and as a guiding catheter for the Tracker-18 microcatheter in patients with intracranial dural arteriovenous fistulas (AVFs), spinal dural AVFs, spinal epidural AVF, meningioma, and acute embolic occlusion of major cerebral vessels. The 4-French guiding catheter was introduced through the transfemoral or transbrachial route. The guiding catheter and the guidewire were advanced to the aortic arch and then turned over just above the aortic valves, and finally the catheter was introduced into the external carotid artery or vertebral artery when the transbrachial approach was selected. Images of the intracranial vessels and spinal dural branches obtained were excellent in all cases. The Tracker-18 could smoothly be advanced to the target artery through the 4-French catheter in all patients. Endovascular treatment with the Tracker-18 can be performed using an ultra-thin 4-French guiding catheter, and safely via the transbrachial route.

Aged↗

PubMed1995

Percutaneous transluminal angioplasty in the treatment of atherosclerotic disease of the anterior cerebral circulation and hemodynamic evaluation.

Nineteen patients between 56 and 76 years of age with clinically symptomatic atherosclerotic stenotic lesions at or distal to the C-5 segment in the carotid arterial system underwent percutaneous transluminal angioplasty (PTA). The 19 patients had a total of 19 stenotic lesions, including two lesions in the C-5 segment, three in the C-4 segment, and three in the C-2 segment of the carotid artery, six in the M1 segment and three in the M2 segment of the middle cerebral artery, and two in the A2 segment of the anterior cerebral artery. Both prior to and more than 6 months after PTA, angiograms were performed and cerebral perfusion was measured using 99mTc-hexamethyl-propyleneamine-oxime single-photon emission computerized tomography, before and after the administration of 10 mg/kg acetazolamide. Percutaneous transluminal angioplasty could be performed in 13 (68.4%) of the 19 patients. The mean degree of stenosis (+/- standard deviation) was 83.1% +/- 8.6% before PTA, but only 35.8% +/- 17.3% on the follow-up angiograms. Restenosis was detected in follow-up angiograms in five (38.5%) of the 13 patients. Seven of the 13 patients exhibited improvement in their neurological condition after PTA and had shown subnormal cerebral perfusion and subnormal vasodilatory response to administration of acetazolamide prior to undergoing PTA. On the other hand, the remaining six patients exhibited no improvement in neurological condition after PTA, and four of these patients (66.7%) had shown normal perfusion and five (83.3%) had shown normal vasodilatory response to administration of acetazolamide prior to undergoing PTA. These findings suggest that PTA may be indicated for patients with atherosclerotic stenotic lesions in the anterior cerebral circulation who have subnormal cerebral perfusion and low vasodilatory response to administration of acetazolamide.

Acetazolamide↗

PubMed1994

The "turn-over" technique for selective cerebral angiography.

In older patients with severe aortic atherosclerosis or pronounced tortuosity of the brachiocephalic vessels, selective catheterisation may be impossible. In order to overcome this difficulty we introduced a new "turn-over" technique. This involves introduction of a long guidewire through the catheter, advancing it and turning it over just above the aortic valves and finally introducing it into each major vessel, followed by the catheter. Selective catheterisation was completely achieved with the turn-over technique in 13 patients. Turning over the catheter just above the aortic valves and introducing it into the vessels was very easy.

Aged↗

PubMed1994

Successful intra-arterial fibrinolysis of the anterior choroidal artery in the acute stage of internal carotid artery occlusion: case report.

A 27-year-old man was admitted to our institution with the sudden development of right hemiparesis and dysarthria beginning an hour after the onset of symptoms on August 9, 1992. The patient was found on admission to have right hemiparesis (2/5), hemihypesthesia, hemianopia, dysarthria; he had transient atrial fibrillation. No abnormalities were detected on computed tomography (CT) scans, and cerebral blood flow studies undertaken following conventional CT scans revealed no low flow regions in the left cerebral hemisphere. But cerebral angiography disclosed an occlusion of the left internal carotid artery with well-developed cross-circulation via the anterior communicating artery and embolus lodged at the level of the anterior choroidal artery. Superselective fibrinolysis using Tracker-18 and 420,000 units of urokinase resulting in complete recanalization of the left anterior choroidal artery without distal migration of the embolus. Immediately after the procedure, his neurologic disturbance underwent complete resolution. In summary, fibrinolysis could be performed but limited to anterior choroidal artery in a case with an occlusion of the internal carotid artery with well-developed cross-flow via the anterior communicating artery; the patient's neurologic condition may deteriorate suddenly if fibrinolysis is incomplete and the embolus migrates to the internal carotid artery.

Acute Disease↗

PubMed1994

Percutaneous transluminal angioplasty for acute stroke due to stenosis of major cerebral vessels: report of two cases.

The Stealth dilation catheter was introduced for the intravascular treatment of two patients with acute and unstable ischemic stroke due to hemodynamically significant stenosis in the one case of the middle cerebral artery and in the other of the vertebral artery. Cerebral perfusion study on the two cases showed a moderately low flow area in the right cerebral hemisphere and in the left cerebellar hemisphere, respectively. Percutaneous transluminal angioplasty (PTA) using the Stealth catheter was conducted. The two cases showed marked improvement in their neurologic state just after PTA with marked increase in cerebral perfusion in the relevant regions.

Acute Disease↗

PubMed1994

Disturbance of autoregulation in patients with ruptured intracranial aneurysms: mechanism of cortical and motor dysfunction.

Serial measurements of local cerebral blood flow were obtained with inhalation of stable xenon and computed tomography prior to and during induced hypertension with continuous infusion of dopamine (7-15 micrograms/kg/min) in 34 patients who underwent surgery for treatment of subarachnoid hemorrhage due to ruptured intracranial aneurysm. Cerebral vasospasm was detected angiographically in all but one of the patients studied. Vasospasm was not symptomatic in 19 patients, but was in the other 15 patients. Disturbance of autoregulation was observed just after surgical operation. In the latter group, local cerebral blood flow in the territory of the middle cerebral artery and the corona radiata on the craniotomy side reached their lowest values, 25.1 +/- 6.8 mL/100 g/min and 15.7 +/- 1.8 mL/100 g/min, respectively, on days 10-14, and each subsequently increased significantly, to 34.3 +/- 7.3 mL/100 g/min and 19.9 +/- 2.0 mL/100 g/min, respectively, during induced hypertension. In conclusion, cortical dysfunction and motor palsy in the patients studied here were thought to be due to significant reduction in local cerebral blood flow in the cortical territories of the middle cerebral artery and corona radiata, respectively.

Adult↗

PubMed1994

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.

Adult↗

PubMed1994

Total excision of a thalamic arteriovenous malformation using an orbito-fronto-malar approach: case report.

A 37-year-old woman was admitted to Osaka Neurological Institute after the sudden onset of left hemiplegia, hemihypesthesia, and ipsilateral hemianopia on February 4, 1992. Computed tomography (CT) disclosed the presence of hemorrhage in the right thalamus extending to the ipsilateral internal capsule. Cerebral angiography after CT scanning disclosed the presence of a cerebral arteriovenous malformation (AVM) fed by copsulothalamic and lateral geniculate body arteries originating from the right anterior choroidal artery. She was operated on with removal of the AVM using a right orbito-fronto-malar approach (OFM approach), which did not require transection of the cerebral parenchyma. The anterior choroidal artery could be followed distally from its origin and small feeding branches originating from the parent artery were easily identified, and the cerebral base could be examined in greater detail than with the conventional frontotemporal approach. The nidus could be excised in its entirety without difficulty. Postoperative angiography confirmed total excision of the AVM. She was transferred to another hospital for rehabilitation on April 13, 1992. Motor strength on the left side had improved to 3/5 by that time. The OFM approach appears to be potentially useful for the resection of inferolateral thalamic AVMs, because it does not require corticotomy and feeding branches can be identified and dealt with prior to other surgical manipulations.

Adult↗

PubMed1994

Percutaneous transluminal angioplasty of stenotic primitive hypoglossal artery--case report.

A 76-year-old female presented with vertebrobasilar insufficiency due to a severe stenosis of the right primitive hypoglossal artery (an unusual carotid-basilar anastomosis) manifesting as recurrent transient ischemic attacks (TIA) associated with quadriparesis and cerebellar ataxia with vertigo, nausea, and vomiting. She had been treated with 100 mg of aspirin per day, but TIA associated with the same symptoms persisted. Cerebral blood flow (CBF) studies disclosed a region of moderately low flow in the posterior fossa. Cerebral angiography demonstrated that the posterior fossa was supplied via the right primitive hypoglossal artery, which was severely stenotic at its origin. Percutaneous transluminal angioplasty using a Stealth catheter, 3.0-mm diameter and 10-mm long, successfully dilated the stenosis. No TIA occurred postoperatively, and a marked increase in CBF was demonstrated in the posterior fossa.

Aged↗

PubMed1994

Lateral approach for anterior thoracic spinal lesions.

A lateral approach, consisting of a modified transversectomy, hemilaminectomy, and adequate transversectomy with costectomy of 7-8 cm, was used to treat four cases of anterior or anterolateral thoracic lesions, including two cases of thoracic disc herniations, one of thoracic meningioma, and one of hypertrophic pachymeningitis. All patients presented with gait disturbance, but recovered well postoperatively except for one who needed rehabilitation of the lower extremities. This approach provides a greater access to the anterior thoracic canal, and can achieve effective anterior decompression, and a good outcome for thoracic spinal disease if recognized early.

Female↗