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I Nakahara

Publications and source records attributed to I Nakahara.

At least 19 recordsLinked to original sources
PubMed1999

Endovascular treatment of aneurysms on the feeding arteries of intracranial arteriovenous malformations.

The association between intracranial aneurysms and arteriovenous malformations (AVMs) is well documented. Recent advances in the understanding of the haemodynamics of this association encourage an aggressive approach to these aneurysms. However, the pathophysiology of these aneurysms is not fully understood and a strategy for their management has not been established. We describe seven patients, with eight aneurysms, on the feeding arteries of AVMs. The aneurysms could be divided into those located 1. proximally on the superficial feeding artery (type I; 4 aneurysms); 2. distally on the superficial feeding artery (type II; 3 aneurysms); and 3. on the deep feeding artery (type III; 1 aneurysm). All aneurysms were treated by the endovascular procedure prior to, or simultaneously with, treatment of the AVM, using detachable coils or liquid embolic material. All aneurysms were obliterated successfully, with no adverse events. Each patient further received treatment of the AVM. None of the patients suffered intracranial haemorrhage after treatment for the aneurysms. Based on our experiences, we discuss the indications for this approach for each type of aneurysm. We believe endovascular treatment could be an important alternative for treatment of aneurysms associated with AVMs, thus reducing the risk of haemorrhage.

Adult↗
PubMed1999

Delayed thrombus propagation after parent artery clipping for giant fusiform aneurysms of the circle of Willis.

BACKGROUND: Obliteration of a giant fusiform aneurysm without significant therapeutic morbidity is extremely difficult. Ischemic complications have been often reported. METHODS: Two patients with giant fusiform aneurysms of the circle of Willis are presented. Both patients underwent proximal parent artery clipping after a bypass procedure. Balloon occlusion tests confirmed both patients' ability to tolerate flow reduction after proximal clipping. RESULTS: Although both patients awoke from anesthesia without neurologic deficit, they developed contralateral hemiparesis several hours after the operation as a result of a small infarct in the basal ganglia. These ischemic events might be attributed to the delayed thrombosis involving the orifice of the distal perforating arteries. CONCLUSIONS: In the treatment for giant fusiform aneurysms of the circle of Willis, special attention should be paid not only to flow reduction, but also to delayed thrombus propagation that may not be predicted by preoperative balloon occlusion testing.

Adult↗
PubMed1999

Combination of intraischemic and postischemic hypothermia provides potent and persistent neuroprotection against temporary focal ischemia in rats.

BACKGROUND AND PURPOSE: It is not known whether a combination of intraischemic and postischemic mild hypothermia provides extra neuroprotection and if so, whether the neuroprotection is persistent. METHODS: Sixty-eight Sprague-Dawley rats were used. In group 1, ischemia and reperfusion were performed under normothermic (N) conditions (control, N-N). In group 2, ischemia was induced and maintained under hypothermic conditions (33 degrees C for 2 hours) and reperfusion was performed under normothermic conditions, H-N. In group 3, both ischemia and reperfusion were performed under hypothermic conditions for an additional 21 hours after the surgery, H-22H. In group 4, ischemia was induced and maintained under hypothermic conditions and reperfusion was performed under hypothermic conditions only for the initial 3 hours (H-3H). In group 5, ischemia was induced and maintained under normothermic conditions and reperfusion was performed under hypothermic conditions (33 degrees C) (N-22H). All rats were perfused 48 hours after the induction of ischemia. In addition, the normothermic or hypothermic therapy used for groups 1, 3, and 4 was performed again, and these rats were killed 30 days after the induction of ischemia. Furthermore, neurological deficits were monitored in groups N-N and H-22H for 4 weeks. RESULTS: In the H-3H and H-22H groups, the total infarct volume was significantly reduced by 41% or 66%, respectively, assessed 48 hours after ischemia. The significant reduction in group H-22H was again confirmed 30 days after ischemia, ie, 50% reduction was observed. In contrast, the reduction in group H-3H (31%) was not significant. The neurological deficits were significantly more severe in the N-N group than in the H-22H group during week 4. CONCLUSIONS: The neuroprotective effects against temporary focal ischemia evaluated by infarct volume and neurological functions by the combination therapy with intraischemic and prolonged postischemic mild hypothermia were persistent in rats. Appropriate design of mild hypothermia therapy extending into the late reperfusion period is important to maximize the neuroprotective effects of hypothermia.

Animals↗
PubMed1999

Prevention of neointimal formation by a serine protease inhibitor, FUT-175, after carotid balloon injury in rats.

BACKGROUND AND PURPOSE: In vivo and vitro studies revealed the activation of thrombin and the complement system in vascular lesion formation during the process of atherosclerosis, along with pathological proliferation of smooth muscle cells. We examined the effect of the synthetic serine protease inhibitor FUT-175 (developed as a potent inhibitor of thrombin and the complement system) on vascular lesions using balloon dilatation-induced neointimal formation in the carotid artery of rats. METHODS: Sprague-Dawley (SD) rats underwent balloon dilatation injury of the left carotid artery to induce neointimal formation. Three groups of these rats (n=8, each) were treated with daily intraperitoneal injections of 1 of the following doses of FUT-175: 0.5, 1.0, or 2.0 mg/d in 1 mL of saline for 7 consecutive days. The control group (n=8) was similarly treated with 1 mL of saline for 7 days. The injections were started immediately after balloon injury. Two weeks after the injury, the left carotid arteries were perfusion-fixed, and the areas of the neointimal and medial layer were analyzed under a microscope. RESULTS: A morphometric analysis revealed that there were significant differences in the intima-media ratio between the 4 groups treated with vehicle (saline) or a low, medium, or high dose of FUT-175 (1.45+/-0.11, 1.08+/-0.06, 0.71+/-0.04, or 0.32+/-0.04, respectively). This suppression was achieved in a dose-dependent manner by the administration of FUT-175 after balloon injury. In the histological study, it was demonstrated that FUT-175 suppresses the production of platelet-derived growth factor (PDGF)-BB in the neointima and the medial smooth muscle cell layer. CONCLUSIONS: After balloon injury activated proteases that were inhibited by FUT-175 were demonstrated to have an essential role in the development of the pathological thickening of the arterial wall.

Animals↗
PubMed1999

[Endovascular surgery for untreated ruptured aneurysm with symptomatic vasospasm].

It is difficult to treat ruptured aneurysms with symptomatic vasospasm. Although direct surgery for such cases is associated with poor outcomes, conservative therapy has the risk of both rerupture and infarction. In two cases of ruptured aneurysms with symptomatic vasospasm, we performed aneurysmal coil embolization with Guglielmi electrodetatchable coils (GDC). At the same time we performed percutaneous transluminal angioplasty (PTA) with papaverine infusion. In both cases, rerupture did not occur and PTA was effective angiographically. A good outcome was achieved in case 1. However, broad cerebral infarction occurred in case 2, in which the patient had shown severe symptomatic vasospasm on admission. In advanced cases, such as in case 2, the outcome is poor. The aneurysm may not be able to be approached before PTA because of severe vasospasm. In such cases, PTA must be performed carefully to avoid aneurysmal rerupture. Intraarterial papaverine infusion is safer than PTA for severe spasm in distal vessels. However the efficacy of papaverine is known to be transient in many cases. It is often difficult to determine the exact relationship between branches and the aneurysm in the presence of vasospasm. In such cases, we recommend that the rupture point be packed and that the aneurysmal neck remain unpacked. After vasospasm is cured and good general condition has been recovered, direct surgery can be performed. In summary, endovascular surgery is an effective option for treatment of ruptured aneurysm with symptomatic vasospasm.

Aged↗
PubMed1998

Increased hepatic glucose production and decreased hepatic glucose uptake at the prediabetic phase in the Otsuka Long-Evans Tokushima fatty rat model.

To investigate the time course of the hepatic glucose metabolism in non-insulin-dependent diabetes (NIDDM), we measured hepatic glucose production (HGP) and first-pass uptake of portal glucose infusion by the liver (HGU) using dual-tracer methods in a NIDDM model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, and in normal controls, Long-Evans Tokushima Otsuka (LETO) rats, at 8, 14, and 28 weeks of age (n = 5, respectively). The fasting plasma glucose level in OLETF rats was significantly higher than in LETO rats at 28 weeks of age (8.9 +/- 1.7 v 6.3 +/- 0.4 mmol/L, P < .01), while there was no significant difference at 8 and 14 weeks. Hyperinsulinemia in OLETF rats appeared at > or = 8 weeks of age. Basal HGP was significantly higher in OLETF than in LETO rats at 8 and 28 weeks (8 weeks, 12.7 +/- 1.7 v 9.4 +/- 1.8 mg x kg(-1) x min(-1), P < .05; 28 weeks, 10.9 +/- 1.6 v 7.1 +/- 1.3 mg x kg(-1) x min(-1), P < .01). At 14 weeks, basal HGP was not significantly different between OLETF and LETO rats. However, at all study points, HGU during a portal glucose infusion was significantly lower in OLETF than in LETO rats (8 weeks, 0.9 +/- 0.2 v 2.3 +/- 0.5, P < .01; 14 weeks, 0.8 +/- 0.3 v 1.4 +/- 0.3, P < .05; 28 weeks, 0.7 +/- 0.2 v 1.4 +/- 0.3 mg x kg(-1) x min(-1), P < .01). Fasting plasma free fatty acid (FFA) levels were not significantly different between OLETF and LETO, except at 8 weeks. Suppression of plasma FFA levels by endogenous insulin during a portal glucose infusion was impaired in OLETF rats compared with LETO rats. In summary, this study demonstrates that derangement of hepatic glucose handling, such as increased basal HGP and decreased HGU, is observed in obese NIDDM model OLETF rats at the prediabetic phase when hyperglycemia is still not apparent. Furthermore, these derangements may be accompanied by impaired lipid metabolism.

Animals↗
PubMed1998

High plasma free fatty acids decrease splanchnic glucose uptake in patients with non-insulin-dependent diabetes mellitus.

It has been proposed that high plasma free fatty acid (FFA) levels observed in patients with non-insulin dependent diabetes mellitus (NIDDM) contribute to the development of their insulin resistance. We examined patients with NIDDM to find whether maintaining plasma FFA levels in the fasting range with a euglycemic hyperinsulinemic clamp combined with an oral glucose load (clamp OGL) would affect insulin-mediated peripheral glucose uptake (PGU) and splanchnic glucose uptake (SGU). Nine NIDDM subjects (age, 55 +/- 3 years; duration of diabetes, 11 +/- 2 years; body mass index, 21.0 +/- 0.4 kg/m2; hemoglobin A1c, 9.0 +/- 0.3%; fasting plasma glucose, 9.4 +/- 3.0 mmol/l, means +/- SEM) were hospitalized and treated with diet, oral hypoglycemic agents or insulin for at least 2 weeks to maintain fasting plasma glucose < 8 mmol/l. All the patients were subjected to two different protocols in a random order. On one protocol, under the hyperinsulinemic condition, FFAs were maintained at the their fasting levels (1.19 +/- 0.08) by triglyceride emulsion infusion (Lipid infusion study, L), and on the other protocol, FFAs were made to fall (0.26 +/- 0.06 mmol/l) with saline instead of triglyceride emulsion infusion (Saline infusion study, S). During euglycemic (L, 5.4 +/- 0.2; S, 5.1 +/- 0.2 mmol/l) hyperinsulinemic (L, 1377 +/- 108; S, 1328 +/- 67 pmol/l) clamp, high FFA levels significantly reduced PGU (L, 26.7 +/- 3.6; S, 32.1 +/- 3.4 mumol.kg-1.min-1, P < 0.05) and SGU (L, 12.1 +/- 4.2; S, 27.5 +/- 5.6%, P < 0.05). In conclusion, high FFA levels in patients with NIDDM impaired insulin-mediated glucose uptake in the splanchnic as well as peripheral tissues.

3-Hydroxybutyric Acid↗
PubMed1998

Circulatory arrest with profound hypothermia during the surgical treatment of large internal carotid artery aneurysm--case report.

A 43-year-old male presented with a cerebral aneurysm manifesting as right facial paresthesia, without neurological deficit. Angiography revealed a large aneurysm (22 mm) of the left internal carotid artery. Intravascular treatment using placement of a detachable coil was attempted, but the coil did not stay in the aneurysmal cavity and the procedure was abandoned. The patient did not tolerate the transient balloon occlusion test of the left internal carotid artery. Therefore, the aneurysm was clipped through an open craniotomy with profound hypothermia (20 degrees C) with cardiac arrest (24 minutes). The aneurysmal dome was collapsed, allowing easy dissection of the posterior communicating artery. The closed chest method was used during the extracorporeal cardiopulmonary bypass. Postoperative angiography revealed complete neck clipping with preservation of carotid blood flow. The patient recovered well and resumed his employment. Circulatory arrest with hypothermia provides several benefits for the surgical treatment of large and giant aneurysms.

Adult↗
PubMed1998

Large and giant middle to lower basilar trunk aneurysms treated by surgical and interventional neuroradiological methods.

Treatment of large and giant aneurysms of the basilar artery remains difficult and controversial. Three large or giant aneurysms of the lower basilar artery were treated with a combination of surgical and interventional neuroradiological procedures. All patients underwent the balloon occlusion test with hypotensive challenge (blood pressure reduced to 70% of the control value). The third patient did not tolerate the test. In the first patient, both vertebral arteries were occluded through a craniotomy. In the second patient, both the aneurysm and the basilar artery were occluded by detached balloons. In the third patient, one vertebral artery was occluded by surgical clipping and the other by detached helical coils and fiber coils. In spite of anti-coagulation and anti-platelet therapy, postoperative thrombotic or embolic ischemia occurred in the second and third patients. Fibrinolytic therapy promptly corrected the ischemic symptoms, but the second patient developed hemorrhagic complications at the craniotomy area 2 hours later. At follow-up examination, the first patient had only 8th cranial nerve paresis, the second patient who had a hemorrhagic complication was bed-ridden, and the third patient had no deficit. Interventional occlusion requires a longer segment of the parent artery compared to surgical occlusion of the parent artery and might cause occlusion of the perforating arteries. However, selected use of various coils can occlude only a short segment of the parent artery. Thus, the postoperative management of thromboembolic ischemia after the occlusion of the parent artery is easier using the interventional technique.

Adult↗
PubMed1997

Surgical extirpation of the posterior hippocampal arteriovenous malformation.

BACKGROUND: Surgical extirpation of medial temporal (AVMs) arteriovenous malformations has been one of the most challenging issues in neurosurgery. Yaşargil classified mediobasal AVM into four subtypes: amygdala, anterior hippocampal, middle hippocampal, and posterior hippocampal lesions. The lesions around the trigone extending forward to the temporal horn, and medially adjacent to the midbrain, can be referred to as posterior hippocampal AVMs. The therapeutic indications and operative approaches for these lesions remain controversial. METHODS: Nine patients underwent surgical resection for AVMs of the posterior hippocampus using a laterobasal approach. RESULTS: In four patients, AVMs were located chiefly within the lateral ventricle, and the lesions were resected using a laterobasal approach through the occipitotemporal sulcus, or through a hematoma cavity within the fusiform gyrus. Clinical improvement followed the procedure in three of four patients. In the remaining five patients, the nidi were located chiefly within the ambient cistern, extending upward to the basal ganglia. Contralateral hemiparesis occurred in three patients. Two patients showed marked improvement following an initial decline in neurologic status. CONCLUSIONS: A laterobasal transventricular approach is suitable for ventricular AVMs, whereas only limited exposure can be afforded through a transventricular, transchoroidal fissure route for the AVMs within the ambient cistern. For these lesions, a conventional subtemporal approach to the tentorial incisura is preferable.

Adult↗
PubMed1997

"Cavernous sinus EEG": a new method for the preoperative evaluation of temporal lobe epilepsy.

PURPOSE: In presurgical evaluation of temporal lobe epilepsy (TLE), invasive methods are necessary if results of various noninvasive methods are not sufficiently convergent enough to identify the epileptogenic area accurately. To detect the epileptiform discharges originating specifically from the mesial temporal lobe, we applied the cavernous sinus catheterization technique. METHODS: We placed Seeker Lite-10 guide wire electrodes into bilateral cavernous sinus through the internal jugular veins to record EEG (cavernous sinus EEG) in 6 patients with intractable TLE. Scalp EEG was simultaneously recorded in all 6 and electrocorticogram (ECoG) was also recorded in 4. RESULTS: The cavernous sinus EEG demonstrated clear epileptiform discharges, sometimes even when they were absent on the simultaneously recorded scalp EEG. The epileptiform discharges recorded from the cavernous sinus electrodes were specifically associated with those in the mesial temporal region on ECoG. Ictal EEG pattern originating from mesial temporal lobe was also clearly documented on the cavernous sinus EEG. CONCLUSIONS: This new, semi-invasive method of identifying epileptogenic areas can detect the epileptiform discharges specifically arising from the mesial temporal lobe; it is as useful as or complements the invasive techniques such as foramen ovale or depth recording.

Adolescent↗
PubMed1997

Endovascular treatment of a partially thrombosed giant basilar tip aneurysm using interlocking detachable coils--case report.

A 65-year-old female presented with visual acuity loss. Magnetic resonance imaging confirmed the presence of a partially thrombosed giant aneurysm on the basilar tip. Cerebral angiography showed the opacified lumen of the aneurysm was 25 x 15 mm with a broad-based neck. Using a transfemoral approach, a microcatheter was guided through the vertebral artery and placed directly into the aneurysm under local anesthesia. Interlocking detachable coils were deposited into the patent portion of the aneurysm, resulting in 95% obliteration of the aneurysm and preservation of the parent artery. No complication was observed during or after surgery. Follow-up angiography 2 months later demonstrated the aneurysm was 95% occluded. No coil compaction was observed. Endovascular coil embolization therapy provides a therapeutic option for management of basilar tip aneurysms.

Aged↗
PubMed1997

Augmentation of hepatic glucose uptake by a positive glucose gradient between hepatoportal and central nervous systems.

To determine the role of the glucose gradient between the hepatoportal system (HPS) and the central nervous system (CNS) in regulating hepatic glucose uptake, experiments were conducted with seven conscious dogs using a hepatic venous catheterization technique. With the infusion of somatostatin (0.8 microg x kg(-1) x min(-1)), glucagon (0.65 ng x kg(-1) x min(-1)), and insulin (27 pmol x kg(-1) x min(-1)), arterial glucose levels could be maintained at 8 mmol/l by adjusting the intravenous glucose infusion (G(inf)) according to the following three periods: 1) peripheral glucose infusion period (PE), G(inf) alone; 2) portal glucose infusion period (PO), G(inf) plus constant glucose infusion into the portal vein (GIR(PV), 55.6 micromol x kg(-1) x min(-1)); 3) portal and brain glucose infusion period (PO+CNS), G(inf) and GIR(PV) plus additional glucose infusion into the unilateral carotid and vertebral arteries to abolish the positive glucose gradient between HPS and CNS. Arterial plasma glucose levels were clamped during the three periods (8.1 +/- 0.1, PE; 8.2 +/- 0.1, PO; 8.2 +/- 0.1 mmol/l, PO+CNS). During PO, when a positive glucose gradient was promoted between HPS and CNS, the net hepatic glucose balance (NHGB) determined by the difference between hepatic glucose inflow and outflow was significantly lower than that of PE (-41.5 +/- 5.3, PO vs. -7.5 +/- 3.4 micromol x kg(-1) x min(-1), PE; P < 0.01). However, this decrease in the NHGB significantly increased during PO+CNS, when the glucose gradient between HPS and CNS was minimized, compared with PO (-21.7 +/- 3.2 micromol x kg(-1) x min(-1), P < 0.05). We conclude that a positive glucose gradient between HPS and CNS is an important regulatory factor of hepatic glucose uptake, but other factors also play important roles because minimizing the glucose gradient between HPS and CNS diminished the net hepatic glucose uptake by 50%.

Animals↗
PubMed1997

[A malignant rhabdoid tumor appearing simultaneously in the kidney and the brain of an infant: case report].

A 6-month-old female was admitted to the hospital with bad temper and decreased sucking power. CT scans revealed tumors in her right kidney and left cerebellum. The patient underwent right radical nephrectomy to excise the kidney tumor. The pathological diagnosis was malignant rhabdoid tumor (MRT). Seven days later, the patient underwent left suboccipital craniectomy for total excision of the cerebellar tumor. The cerebellar tumor existed extraaxially, and consisted of a solid mass lesion and a cystic lesion. Histological examination revealed that it was also a malignant rhabdoid tumor. A follow-up CT, 1.5 months after surgery, revealed a recurrence of the kidney tumor and metastasis to the chest wall and lung. The patient received 16.9 Gy radiotherapy to the abdominal tumor and chemotherapy with etoposide, carboplatin, and ifosfamide. However, she died of respiratory insufficiency 4 months after surgery, though neither recurrence nor metastasis was found in the brain. Nor was there evidence of leptomeningeal dissemination. MRT is a highly malignant tumor that occurs most frequently in the kidney. However, it can also occur in other tissues, including the brain. This tumor occurs most commonly in children under 2 years of age. There is a 3:2 male predominance. The median length of overall survival of MRT in the brain is 6 months. MRT contains nests or sheets of rhabdoid cells. A typical rhabdoid cell has an eccentric round nucleus with a prominent nucleolus and a plump cell body. MRT is composed entirely or partly of rhabdoid cells. Many MRTs have other components, such as PNET areas, mesenchymal area, and epithelial areas. For this reason, they are sometimes called atypical teratoid/rhabdoid tumors. MRTs in the brain contain fewer rhabdoid cell areas than MRT in the kidney. This makes diagnosing MRT in the brain more difficult. A careful search of the entire specimen for variations in pattern and cell type, along with application of immunohistochemical methods is the most useful method of obtaining a diagnosis. In our case, the cerebellar tumor consisted of rhabdoid cell areas, mesenchymal areas, and PNET areas. The cerebellar tumor contained fewer rhabdoid cell areas than the kidney tumor. However, the rhabdoid cell areas in the cerebellar tumor were almost the same as those in the kidney tumor. Furthermore, immunohistochemical staining was positive for vimentin and keratin in the rhabdoid cell areas. Therefore, we were able to make a diagnosis of MRT. It is possible that some of the previously reported cases diagnosed as CNS PNET were actually MRT in the brain, especially if the cases were associated with MRT in the kidney.

Cerebellar Neoplasms↗
PubMed1997

[A case of cavernous dural arteriovenous fistula resulting in intracerebral extravasation during transvenous embolization].

Cortical venous drainage has been described as one of the major risk factors for dural arteriovenous fistula, which may induce venous hypertension leading to venous ischemia or intracerebral hemorrhage. However, it is rather rare to observe cortical venous drainage manifesting in this way in the cavernous sinus region. We report a case of a 55-year-old gentleman with a right cavernous dural arteriovenous fistula, presenting with conjunctival chemosis, exophthalmus and ocular hypertension on the affected side. Magnetic resonance imaging showed a small intracerebral hemorrhage in the right frontal lobe. Cerebral angiography revealed a dural arteriovenous fistula in the right cavernous sinus draining into the right olfactory vein via the uncal vein, as well as into the superior and inferior ophthalmic veins. This unusual cortical venous reflux was thought to be consistent with the intracerebral hemorrhage found on the magnetic resonance imaging. The patient underwent transvenous embolization for the dural arteriovenous fistula using an inferior petrosal catheterization into the uncal vein was difficult, and the cortical venous reflux through the vein seemed to be slight. However, extravasation of the contrast material occurred in the right frontal lobe after obliteration of the ophthalmic veins during the procedure. The cause of the extravasation was suspected to be the same olfactory vein that had been involved in the previous intracerebral hemorrhage. The obliteration of the dural fistula was continued rapidly, and the fistula disappeared after the embolization. Neurologically, the patient had no noticeable troubles, except for a mild headache. The pretreatment symptoms were alleviated within several days, and the patient was discharged in a week. We emphasize the following points from this rare case in order to facilitate a safer procedure during transvenous embolization for cavernous dural arteriovenous fistula. It is important to obliterate the cortical venous drainage as early as possible, even if the reflux is small or the catheterization is difficult. Repeated, careful sinography is useful for the evaluation of the drainage pattern at certain stages during the transvenous embolization procedure.

Arteriovenous Fistula↗
PubMed1996

Embolization of cerebral aneurysms with a liquid embolus, EVAL mixture: report of three cases.

Embolization of three surgically difficult cerebral aneurysms was performed using our newly developed non-adhesive embolic material, EVAL mixture (ethylene vinyl alcohol copolymer). Conventional embolic materials such as detachable balloons or microcoils were not used because of a large or irregular aneurysmal neck. After temporary occlusion of the parent artery with a superselective balloon catheter, the EVAL mixture was slowly injected through a microcatheter placed in the aneurysm or parent artery. The locations of the aneurysms were anterior communicating artery, basilar artery-posterior cerebral artery and basilar artery-anterior inferior cerebellar artery (BA-AICA). One aneurysmal occlusion and 2 parent artery occlusions were performed. Patients had no persistent deficits. The patient with the BA-AICA aneurysm associated with an arteriovenous malformation died of rupture of the residual AVM due to haemodynamic change 2 weeks after embolization. In selected and limited cases, embolization of surgically difficult cerebral aneurysms using EVAL mixture was more effective and safer than embolization using conventional embolic materials such as balloons and microcoils.

Adult↗
PubMed1995

Changes in cerebral blood flow induced by balloon test occlusion of the internal carotid artery under hypotension.

Balloon test occlusion (BTO) of the internal carotid artery (ICA) combined with cerebral blood flow (CBF) study has proved to be a sensitive test for prediction of the outcome of permanent vessel occlusion. In this study, we evaluated the acute changes in regional CBF during BTO under hypotension in order to examine the possible risk of cerebral ischaemia after surgical treatment. Eleven patients in whom surgical carotid sacrifice was planned underwent BTO combined with CBF studies using technetium-99m hexamethyl-propylene amine oxime single-photon emission tomography under hypotension by decreasing the systemic blood pressure by about 50 mm Hg using a ganglion blocking agent. All patients showed a mild to severe decrease in CBF in the ipsilateral ICA territory relative to the contralateral side. A decrease in CBF of greater than 20% was observed in nine patients (82%), and two of them showed a decrease exceeding 40%. However, no ischaemic symptoms were demonstrated during scanning with hypotensive BTO. Our results suggest that in many patients with negative normotensive BTO, a considerable reduction in CBF would occur during hypotension. This procedure may predict a possible risk of hypotensive accident during and/or after surgery.

Adult↗