Published papers

We report 5 patients (2 females and 3 males) with endovascular coil embolizations for ruptured dissecting aneurysms of the vertebral artery (VA). The age of the patients varies between 44 and 66 (mean 54.8) years. All patients had a Hunt and Kosnik Grade of V at admission. One patient had a dissecting aneurysm of the VA distal to the PICA. One patient had a dissecting aneurysm of the VA without the PICA. Three patients had a dissecting aneurysm of the VA involving the PICA. One patient with a dissecting aneurysm of the VA involving the PICA underwent proximal occlusion, and the other 4 patients underwent internal trapping. All patients underwent endovascular coil embolizations on the day or the next day of the onset. Subsequent rupture occurred in 4 patients before embolization. The Glasgow Outcome Scale at 3 months after the embolization was good recovery in 3 patients. We had no ruptured aneurysm and no coil compaction at 0 to 40 months (mean 26.2 months) after embolization. Our experience showed that the internal trapping for ruptured dissecting aneurysms of the vertebral artery should be performed as soon as possible, even if the patients have a Hunt and Kosnik Grade of V.

In the embryo, the primary head sinus (PHS) is the first venous drainage channel in the craniocervical region. During embryonic development, this channel regresses and usually disappears completely; accordingly, a remnant of the PHS is an extremely rare condition and has been described in only a few previous studies. Here, we report a case of remnant of the PHS with a dural arteriovenous fistula (dAVF) in an adult. The remnant of the PHS had penetrated the petrous bone to run from the middle fossa to the jugular bulb and served as a drain for the middle fossa dAVF. We used digital subtraction angiography and reconstructed cone-beam computed tomography in 3D rotational angiography to obtain detailed anatomic information about the remnant PHS and additionally scrutinised and discussed its features.

Dural sinus malformation (DSM) is a rare paediatric vascular malformation characterised by abnormal dilation of the posterior dural sinus. Owing to its rarity, the pathophysiology of DSM has not been fully elucidated. We report a case of prenatally diagnosed DSM with an unusual clinical course. We detected DSM in a male foetus in the 26th week of gestation by using foetal ultrasonography. Although the DSM regressed during the foetal stage and the arteriovenous shunt was insignificant in the neonate, the shunt rapidly developed four months after birth. The neonate also had postnatal de novo brainstem cavernous malformation (CM), which also developed rapidly, supposedly due to the aggravated venous hypertension resulting from the DSM. We successfully treated the aggravated shunts by endovascular transarterial and transvenous embolisation six times over two years and, subsequently, the clinical condition and the size of the brainstem CM became stable. The DSM and CM seemed to have a metameric origin. Such aberrant cases could help to further the understanding of DSM.

Objective: The Amplatzer vascular plug (AVP) is a new embolic device with advantages in embolization of high-flow vessels. We report a case involving implantation of an AVP into the retromandibular vein and coil-embolization of an arteriovenous fistula (AVF).Case presentation: We present the case of a 31-year-old woman with an external carotid artery (ECA)-retromandibular vein AVF. She complained of pulsatile tinnitus after a sagittal split-ramus osteotomy. The high-flow left ECAretromandibular vein AVF was depicted in the arterial phase using selective external carotid angiography (ECAG). Endovascular embolization treatment of the fistula using an AVP and coils was planned. We initially intended to introduce the AVP into the fistula via a transvenous route through the left external jugular vein, but could not pass the 5-Fr guiding catheter round the hairpin curve between the fistula and ECA. We therefore changed treatment strategy, placing an 8 mm AVP into the retromandibular vein. Fistula closure was almost obtained after implantation, but shunt flow from a narrow channel remained. We then embolized the fistula using coils, from the AVP to the fistula inlet. The fistula was occluded using five coils.Conclusion: We treated the patient with implantation of an AVP in the retromandibular vein and coil-embolization of the AVF. Advantages of the AVP are its stability for high-flow vessel occlusion and its cost-effectiveness when compared with coils. However, this device has disadvantages in the ease of its delivery to distal vessels. Therefore, using this device in craniofacial lesions needs technical refinement.

Objective: Regional cerebral blood flow (CBF) increasing focally at sites of neural activity is called "hemodynamic response (HDR)". In cases with severe cerebral ischemia, HDR may be disturbed and cause disruption of normal neuro-vascular coupling. HDR was measured during a motor task using functional near infrared spectroscopy (fNIRS) in cases with severe cervical internal carotid artery (ICA) stenosis before and after carotid artery stenting (CAS). Ischemia and the influence of therapy for it on HDR was analyzed.Methods: Seventeen right-handed patients with severe cervical ICA stenosis admitted for CAS were examined. fNIRS during a motor task was performed and concentration changes in oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HbR), and total hemoglobin (tHb) were calculated in these patients in addition to routine evaluations. The same measurements were repeated after CAS and serial data were evaluated. In order to analyze the relevance of HDR to CBF status, Xenon-enhanced computed tomography (Xe-CT) was performed before and after CAS.Results: Some abnormalities in the HDR curve and its recovery after CAS were detected, including a delay in peak time of tHb concentration, of more than 10 seconds during the 20 second stimulation, in 9 cases. TTP0.7 (time to peak) value, defined as the time to reach seventy percent of maximum tHb concentration, was observed to be higher in patients with low CBF at rest before CAS. In the group with a high TTP0.7 value, CBF at rest before CAS was lower than 35mL/100g/min., significantly lower than the group without a high TTP0.7 value (P<0.01). Additionally, in the group with a high TTP0.7 value, CBF increase after CAS was significantly higher than the group with a lower TTP0.7 value (P<0.01).Conclusions: In some cases with severe ICA stenosis, cortical hemodynamics, and oxygen metabolism during functional activation are disturbed, and CAS can modulate these changes. This result is important in that intervention for cervical IC stenosis can not only reduce ischemic events, but also influence cortical hemodynamics during functional activity.

PURPOSE: Although neuroradiologists and skull base neurosurgeons are aware of the existence of veins within the clivus, such vessels have seldom been described in the literature. The aim of the present study is to elucidate the detailed venous structure of the clivus. METHODS: Computed tomography digital subtraction venography (CT-DSV) images of 50 unruptured aneurysm cases were examined retrospectively. RESULTS: Eighteen emissary veins were identified in 14 (28.0%) cases. A half of the emissary veins connected the inferior petrosal sinus with the inferior petro-occipital vein (IPOV) in the middle clivus. The clival diploic vein (CDV) was identified in 14.0% of cases, 42.9% of which had the clivus of the presellar type. The CDV was connected to the posterior intercavernous sinus or the rostral end of the basilar plexus superiorly, and was connected to the IPOV, anterior condylar vein, marginal sinus, or the anterior condylar confluence. CONCLUSION: The CDV provides collateral channels between the cavernous sinus and the internal jugular vein and the inferior petrosal sinus and the IPOV. Understanding of the emissary veins in the clivus and the CDV is valuable for skull base surgery, especially for endonasal endoscopic skull base procedures.

This paper reports the case of a ruptured aneurysm in the vasa corona at the craniocervical junction with dysgenesis of the posterior inferior cerebellar artery (PICA). Dysgenesis of the proximal PICA in the present case caused the development of a pial anastomosis in the vasa corona, resulting in the formation of an aneurysm because of increased haemodynamic stress at the vasa corona. The aneurysm was successfully treated with transarterial coil embolization. The clinical entity in the present case is extremely rare and it is important to consider an aberrant vascular anomaly as the cause of an isolated spinal aneurysm.