Kiyoshi Kazekawa

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.

Histological changes in brain tissue and vasculature after intracarotid infusion of organic solvents in rats

Organic solvents, such as ethanol or dimethyl sulphoxide (DMSO), have been used in liquid embolic agents. To investigate the effects of these solvents on the cerebral blood vessels and cerebral tissue, we subjected Wistar rats weighing 250–300 g to internal carotid artery infusion of 0.2 ml diluted ethanol (10 %, 40 % or 70 %) or anhydrous DMSO (100 %). Some rats were sacrificed 5 min after the infusion and the remainder at 10 days. Rats injected with ethanol at high concentration or DMSO showed extensive exudation of Evans blue at the site of injection 5 min after infusion, together with full-thickness necrosis of the wall of vessels and swelling of brain cells. In contrast, rats injected with 10 % or 40 % ethanol solution showed necrosis of only the intimal layer and partial necrosis of the medial layer and no brain swelling was observed. These findings suggest that ethanol at low concentration can be used as a relatively safe solvent for liquid embolic substances.

Determinants of Poor Outcome After Aneurysmal Subarachnoid Hemorrhage when both Clipping and Coiling Are Available: Prospective Registry of Subarachnoid Aneurysms Treatment (PRESAT) in Japan

OBJECTIVE To examine current determinants of poor outcome after aneurysmal subarachnoid hemorrhage (SAH) when ruptured aneurysms are treated with either microsurgery (clipping) or endovascular treatment (coiling) depending on each patients characteristics. METHODS Between March 2006 and February 2007, 534 patients with SAH were enrolled in the Prospective Registry of Subarachnoid Aneurysms Treatment (PRESAT) project. Patients were treated according to the preference of investigators who were experienced in performing both clipping and coiling. Factors influencing poor outcome (12-month modified Rankin Scale [mRS], 3-6) were determined using multivariate logistic regression analyses. RESULTS In this cohort, 32.4% of patients were World Federation of Neurosurgical Societies (WFNS) grade IV-V, and 28.1% had a poor outcome. Clipping was preferably performed for small aneurysms with a wide neck and for middle cerebral artery (MCA) aneurysms, whereas coiling was preferred for larger, internal carotid artery (ICA) and posterior circulation aneurysms. In addition to increasing age, admission WFNS grade IV-V, preadmission aneurysmal rerupture, vasospasm-induced cerebral infarct, pneumonia, sepsis, shunt-dependent hydrocephalus and seizure, postclipping hemorrhagic complications (odds ratio 4.8, 95% confidence interval 1.5-15.3, P < 0.01), and postcoiling ischemic complications (odds ratio 4.4, 95% confidence interval 1.3-15.2, P < 0.05) significantly caused poor outcomes, although the complications did not affect mortality. Type of treatment modality and size and location of aneurysms did not influence outcome. CONCLUSIONS Introducing an endovascular treatment option has made aneurysm characteristics less important to outcome, but procedural complications are problematic and should be reduced to improve outcome.

Nontoxic embolic liquids for treatment of arteriovenous malformations

Interventional radiology is becoming one of the standard treatments of arteriovenous malformation (AVM). Cyanoacrylate derivatives and polymer solutions are widely used to occlude the AVM nidus by their injection through a catheter, but they are far from satisfactory embolic liquids. For instance, cyanoacrylate derivatives sometimes glue the catheter to the artery, resulting in serious complications; in addition, the organic solvents used to dissolve polymers cause damage to the surrounding brain tissue of the AVM. Therefore, we attempted to develop embolic liquids by dissolving poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) in Iopamiron with an addition of a small amount of ethyl alcohol. This new embolic liquid is not cytotoxic and is easily injected into the AVM through a thin, long catheter to effectively occlude the AVM.

Meningeal melanocytoma in the left frontal region

We report a rare case of meningeal melanocytoma in the left frontal region. A 45-year-old man complained of a headache. Magnetic resonance (MR) scanning showed characteristic patterns: a slightly high signal intensity mass in the left frontal region on the T1-weighted image and a low signal intensity on the T2-weighted image. The patient underwent gross total removal of the tumor. The postoperative course was uneventful. After two years, there was a small local recurrence. The histological finding of the tumor showed meningeal melanocytoma. To our knowledge, this is the second published report of a meningeal melanocytoma in the supratentorial region.

Intraprocedural plaque protrusion resulting in cerebral embolism during carotid angioplasty with stenting

An 82-year-old man with an asymptomatic left high-grade carotid stenosis was treated with carotid artery stenting (CAS) under distal protection. The procedure consisted with predilation with a 5 × 40 mm percutaneous transluminal angioplasty (PTA) balloon, deployment of a 10 × 20 mm self-expandable stent, post-dilation with a 7 × 20 mm PTA balloon, and aspiration of debris with 60 ml of blood. The cervical carotid angiogram immediately after deflation of the distal blocking balloon demonstrated a small in-stent filling defect of the contrast medium that protruded from the anterior wall of the carotid artery. The following cranial carotid angiogram showed abrupt occlusion of the left middle cerebral artery (MCA). Because the in-stent lesion had vanished in the repeat study after recognition of this embolic event, it was suggested that an embolus had been liberated from the in-stent lesion, reaching the left MCA and obliterating it. In this case, the embolus was speculated to originate in the ruptured plaque, which protruded into the stent through the cells of the device and became liberated into the bloodstream. Attention should be paid so as not to overlook any plaque protrusion, which may be seen subsequently as a cerebral embolism on the angiogram obtained immediately after CAS.

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.

Percutaneous transvenous embolisation of iatrogenic vertebral arteriovenous fistula

Two patients presented with vertebral arteriovenous fistulae following unintentional puncture of the vertebral artery. A percutaneous transvenous approach was used in both cases and the fistula was successfully embolised with microcoils. A complete cure was achieved in both patients.

Carotid Artery Stenting for Calcified Lesions

BACKGROUND AND PURPOSE: Our aim was to assess the feasibility of carotid artery stent placement (CAS) for calcified lesions. MATERIALS AND METHODS: Using embolic protection devices (EPDs), we performed 51 CAS procedures in 43 patients with severe carotid artery stenosis accompanied by plaque calcification. Before intervention, all lesions were subjected to multidetector-row CT. The arc of the circumferential plaque calcification was measured on axial source images at the site of maximal luminal stenosis, and the total volume of the plaque calcification was determined. The angiographic outcome immediately after CAS, and intra- and postoperative complications were recorded. RESULTS: The mean arc of calcification was 201.1 ± 72.3° (range, 76–352°), and the mean of the total calcification volume was 154.9 ± 35.4 mm3 (range, 92–2680 mm3). Balloon rupture occurred in 1 procedure (2.0%) at predilation angioplasty; all 51 CAS procedures were successful without clinical adverse effects. Although there was a correlation between the arc of plaque calcification and residual stenosis (r = 0.6, P < .001), excellent dilation with residual stenosis ≤30% was achieved in all lesions. There was no correlation between the total volume of calcification and residual stenosis. None of the patients developed stroke or death within 30 days of the CAS procedure. CONCLUSION: CAS by using EPDs to treat lesions with plaque calcification is feasible even in patients with near-total circumferential plaque calcification.

Intraprocedural prediction of hemorrhagic cerebral hyperperfusion syndrome after carotid artery stenting.

Hyperperfusion syndrome (HPS) is a rare but severe complication after carotid artery stenting (CAS). Reliable methods for predicting HPS remain to be developed. We aimed to establish a predictive value of hemorrhagic HPS after CAS. Our retrospective study included 136 consecutive patients who had undergone CAS. We determined the cerebral circulation time (CCT) by measuring the interval between the point of maximal opacification of the terminal portion of the internal carotid artery and the cortical vein. We calculated intraprocedural CCT changes (ΔCCT) by subtracting postprocedural CCT values from preprocedural CCT values. The mean ΔCCT was 0.9 ± 0.9 seconds; 3 patients (2.2%) with prolonged ΔCCT (2.7, 5.4, and 5.8 seconds) developed HPS. The cutoff time of 2.7 seconds predicted hemorrhagic HPS retrospectively with 100% sensitivity and 99% specificity. Our findings suggest that post-CAS HPS can be predicted by using the ΔCCT value obtained by intraprocedural digital subtraction angiography. Patients with a ΔCCT >2.7 seconds require careful intensive hemodynamic and neurologic monitoring after CAS.