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Fernando V. Viñuela, Gerard M. Debrun, Allan J. Fox, and Shinichi Kan

✓ The authors describe a system comprising a small latex balloon attached to a Teflon catheter. The balloon has a distal calibrated leak which is used for intravascular embolization with isobutyl-2-cyanoacrylate. The balloon is easily detached after embolization. The combination of manual control of the balloon-catheter system, plus the ability of the balloon to navigate intra-arterially with the blood flow, makes this system suitable for superselective angiography and embolization of lesions supplied by the external carotid artery (ECA). This system avoids intimal dissection and concomitant arterial vasospasm when trying to negotiate steep distal curves of the ECA branches. Experimental embolization of several branches of the ECA in the dog, and clinical examples of treatment of dural arteriovenous malformations in three patients are described.

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Fernando Viñuela, Allan J. Fox, Shinichi Kan, and Charles G. Drake

✓ A case is reported of a large spontaneous right posterior inferior cerebellar artery fistula in which the patient presented with a right cerebellopontine (CP) angle and right cerebellar syndrome. The patient was successfully treated by balloon occlusion at the fistula site. The location of the arteriovenous fistula, the mass effect of its enlarged draining veins on the cerebellum and CP angle structures, and the simple therapeutic endovascular occlusion with a detachable balloon make this case unique.

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Satoru Shimizu, Takao Sagiuchi, Takahiro Mochizuki, Shinichi Kan, and Kiyotaka Fujii

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Akira Kurata, Yoshio Miyasaka, Takatomo Yoshida, Masatake Kunh, Kenzoh Yada, and Shinichi Kan

✓ A case is presented of tentorial dural arteriovenous malformation (AVM) associated with visual hallucinations and quadrant hemianopsia. Computerized tomography (CT) and magnetic resonance imaging showed an ischemic region, mainly affecting the white matter of the right occipital lobe, that was defined as an area of increased blood volume on dynamic CT scans and as a decrease in cerebral blood flow on N-isopropylp-123I-iodoamphetamine single-photon emission CT scans. Angiography demonstrated venous congestion, probably because the retrograde arterial inflow from the dural AVM into the corticomedullary vein was direct and not via the sinuses. The symptoms and radiological findings improved immediately after endovascular treatment. The origin of these symptoms was fully evaluated and confirmed to be a reversible ischemic change caused by disturbance of the volume of venous return over an extensive area.

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Chieki Wada, Akira Kurata, Ryuichi Hirose, Yoshiaki Tazaki, Shinichi Kan, Yoshihiro Ishihara, and Toru Kameya

✓ Ependymoblastoma is considered to be a primitive malignant glioma with ependymal differentiation. This rare tumor occurs in very early life and shows rapid growth and a diffuse infiltration through the leptomeningeal space. The tumor cells are highly immature, with numerous mitoses and multilayered ependymal rosettes. The ependymoblastoma described in this report was found in a 17-year-old girl. In spite of detailed clinical and postmortem examinations, no definite primary site was identified in the neuraxis. The lesion spread predominantly throughout the leptomeningeal space. Histological analysis strongly suggested that this tumor originated from a heterotopic glial nest in the subarachnoid space. The absence of immunohistochemical neural tissue markers, glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, and neurofilaments ruled out neuronal or glial differentiation. The authors were unable to find any previous report of primary leptomeningeal ependymoblastoma.

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Akira Kurata, Hidehiro Oka, Taketomo Ohmomo, Hitoshi Ozawa, Sachio Suzuki, Kiyotaka Fujii, Shinichi Kan, Yoshio Miyasaka, and Harue Arai

✓ This 44-year-old man with Ehlers—Danlos syndrome (EDS) Type IV presented with hemiparesis and the Gerstmann syndrome. Left carotid artery (CA) angiography revealed a dissecting aneurysm with severe stenosis located in the common CA; the lesion was successfully treated with a stent graft. The patient's clinical course after endovascular surgery was uneventful, without occurrence of megacolon. The literature for spontaneous CA dissection in EDS Type IV cases is reviewed and points for investigation and treatment are discussed.

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Akira Kurata, Sachio Suzuki, Kazuhisa Iwamoto, Kuniaki Nakahara, Madoka Inukai, June Niki, Kimitoshi Satou, Masaru Yamada, Kiyotaka Fujii, Shinichi Kan, and Toshiro Katsuta

Object

The transvenous approach via the inferior petrosal sinus (IPS) is commonly used as the most appropriate for carotid-cavernous fistula (CCF) or cavernous sinus sampling. However, sometimes the IPS is not accessible because of anatomical problems and/or complications, therefore an alternative route is needed. In this paper, the authors present and discuss the utility of a transvenous approach to the cavernous sinus via the inferior petrooccipital vein.

Methods

Four patients, 3 with dural CCFs and the other with Cushing disease, in whom endovascular surgical attempts failed using a conventional venous approach via the IPS, underwent a transvenous approach to the cavernous sinus via the inferior petrooccipital vein (IPOV). One dural CCF case had only cortical venous drainage, the second CCF also mainly drained into the cortical vein with slight inflow into the superior ophthalmic vein and inferior ophthalmic vein, and the third demonstrated drainage into the superior and inferior ophthalmic veins and IPOV.

Results

In all cases, the cavernous sinus could be accessed successfully via this route and without complications.

Conclusions

The transvenous approach to the cavernous sinus via the IPOV should be considered as an alternative in cases when use of the IPS is precluded by an anatomical problem and there are no other suitable venous approach routes.

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Sachio Suzuki, Akira Kurata, Taketomo Ohmomo, Takao Sagiuchi, Jun Niki, Masaru Yamada, Hidehiro Oka, Kiyotaka Fujii, and Shinichi Kan

✓Application of endovascular surgery for very small aneurysms is controversial because of technical difficulties and high complication rates. The aim in the present study was to assess treatment results in a series of such lesions at one institution.

Since 1997, endovascular surgery has been advocated for very small ruptured aneurysms (<3 mm in maximum diameter) that fulfill the criterion of a fundus/neck ratio greater than 1.5. Twenty-one patients were treated, for whom the World Federation of Neurosurgical Societies classification before treatment was Grade I in 10, Grade II in two, Grade III in two, Grade IV in five, and Grade V in two. The aneurysm location was the internal carotid artery in four, the anterior communicating artery in 11, the middle cerebral artery in one, and the vertebrobasilar system in five. In all patients, endovascular surgery was performed using Guglielmi detachable coils after induction of general anesthesia. Initially, the presumed volume of the lesions was calculated for each aneurysm. Thereafter, the appropriate coil length was decided according to the volume embolization ratio, as 30 to 40%. In all attempts to obliterate aneurysms a single coil was used.

All aneurysms were completely obliterated as confirmed by postembolization angiography, without procedure-related complications. During the follow-up period only one patient needed additional coil embolization for a growing aneurysm. Final outcomes were good recovery in 15 patients, moderate disability in five, and severe disability in one.

Appropriate selection of patients and coils, and use of sophisticated techniques allow a good outcome for patients with very small aneurysms.

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Victor M. Lu, Evan M. Luther, Michael A. Silva, Turki Elarjani, Ahmed Abdelsalam, Ilko Maier, Sami Al Kasab, Pascal M. Jabbour, Joon-Tae Kim, Stacey Q. Wolfe, Ansaar T. Rai, Marios-Nikos Psychogios, Edgar A. Samaniego, Adam S. Arthur, Shinichi Yoshimura, Jonathan A. Grossberg, Ali Alawieh, Isabel Fragata, Adam Polifka, Justin Mascitelli, Joshua Osbun, Min S. Park, Michael R. Levitt, Travis Dumont, Hugo Cuellar, Richard W. Williamson Jr., Daniele G. Romano, Roberto Crosa, Benjamin Gory, Maxim Mokin, Mark Moss, Kaustubh Limaye, Peter Kan, Dileep R. Yavagal, Alejandro M. Spiotta, and Robert M. Starke

OBJECTIVE

Although younger adults have been shown to have better functional outcomes after mechanical thrombectomy (MT) for acute ischemic stroke (AIS), the significance of this relationship in the adolescent and young adult (AYA) population is not well defined given its undefined rarity. Correspondingly, the goal of this study was to determine the prognostic significance of age in this specific demographic following MT for large-vessel occlusions.

METHODS

A prospectively maintained international multi-institutional database, STAR (Stroke Thrombectomy and Aneurysm Registry), was reviewed for all patients aged 12–18 (adolescent) and 19–25 (young adult) years. Parameters were compared using chi-square and t-test analyses, and associations were interrogated using regression analyses.

RESULTS

Of 7192 patients in the registry, 41 (0.6%) satisfied all criteria, with a mean age of 19.7 ± 3.3 years. The majority were male (59%) and young adults (61%) versus adolescents (39%). The median prestroke modified Rankin Scale (mRS) score was 0 (range 0–2). Strokes were most common in the anterior circulation (88%), with the middle cerebral artery being the most common vessel (59%). The mean onset-to–groin puncture and groin puncture–to-reperfusion times were 327 ± 229 and 52 ± 42 minutes, respectively. The mean number of passes was 2.2 ± 1.2, with 61% of the cohort achieving successful reperfusion. There were only 3 (7%) cases of reocclusion. The median mRS score at 90 days was 2 (range 0–6). Between the adolescent and young adult subgroups, the median mRS score at last follow-up was statistically lower in the adolescent subgroup (1 vs 2, p = 0.03), and older age was significantly associated with a higher mRS at 90 days (coefficient 0.33, p < 0.01).

CONCLUSIONS

Although rare, MT for AIS in the AYA demographic is both safe and effective. Even within this relatively young demographic, age remains significantly associated with improved functional outcomes. The implication of age-dependent stroke outcomes after MT within the AYA demographic needs greater validation to develop effective age-specific protocols for long-term care across both pediatric and adult centers.