Lateral Suboccipital Infrafloccular Approach with Extensive Arachnoid Dissection for Vertebral Artery-Associated Hemifacial Spasm: Two-Dimensional Operative Video.

Hemifacial spasm (HFS) is generally caused by compression of the root exit zone (REZ) of the facial nerve by the anterior and posterior inferior cerebellar arteries and occasionally the vertebral artery (VA). Owing to its large caliber and high stiffness, microvascular decompression (MVD) for VA-associated HFS is considered more difficult, and the result is worse than for HFS not associated with the VA.1,2 Therefore, a safer, more reliable MVD is required for VA-associated HFS. In Video 1, we demonstrate our MVD technique in a 57-year-old woman who presented with left HFS owing to facial nerve compression by a dolichoectatic VA. A lateral suboccipital infrafloccular approach with extensive arachnoid dissection was performed. Arachnoid dissection was started from the cisterna magna and continued from the caudal to the rostral direction. This extensive arachnoid dissection provided access to the facial nerve REZ through the infrafloccular route with gentle retraction of the flocculus in the caudorostral direction, while avoiding strong retraction of cranial nerve VIII and the cerebellum. In addition, we were able avoid damaging the neurovascular structures in the operative field. This is mandatory to make the operative field bloodless and facilitate identifying the relationship between the facial nerve REZ and the offending vessels. MVD of the facial nerve REZ was achieved. The patient's postoperative course was uneventful, and her HFS resolved postoperatively. Patient consent was obtained to perform the surgery and to publish the surgical video.

A Case of Posterior Communicating Artery Aneurysm Accompanied with Infundibular Dilatation Mimicking a Double-Hump Aneurysm.

Posterior communicating artery (PComA) aneurysms are common cerebral aneurysms. In cases of PComA aneurysms accompanied by anatomical variations of PComA, such as hypoplasia, hyperplasia, or infundibular dilatation, it is challenging to completely determine the relationship between the parent artery, daughter arteries, and the aneurysmal neck preoperatively. We present a case of a ruptured PComA aneurysm originating from the PComA, accompanied by infundibular dilatation, which was preoperatively diagnosed as a double-hump PComA aneurysm with hypoplastic or absent PComA, based on computed tomography (CT) angiography images. This case emphasized that CT angiography does not always visualize the entire vasculature. A more meticulous dissection of the retrocarotid space should be performed to confirm the relationship between the parent artery, daughter arteries, and aneurysmal neck, especially when digital subtraction angiography is omitted, and clipping is planned for double-hump PComA aneurysms, wherein the PComA is not clearly depicted on preoperative CT angiography.

Microsurgical Resection of Hybrid Nerve Sheath Tumor Involving the Orbit and Lateral Wall of the Cavernous Sinus: 2-Dimensional Operative Video.

Surgical removal of the tumor involving both the orbital and cavernous sinus remains challenging. Hybrid nerve sheath tumors (HNSTs) are defined as benign peripheral nerve sheath tumors with combined features of more than one type of benign peripheral nerve sheath tumors, including schwannoma, neurofibroma, and perineurinoma.1 They rarely arise from the orbit.1-3 This video shows the microsurgical resection of HNST involving both the orbit and lateral wall of the cavernous sinus. A 43-yr-old woman presented with 1-yr history of a slowly growing painless mass in her left medial eyelid. Neuroimaging examinations demonstrated a multilobulated and well-demarcated mass with a heterogeneous enhancement located in the extraconal region, just above the levator muscle, and extending from the eyelid to the middle fossa through the superior orbital fissure. Based on the neuroimaging features, we diagnosed it as trigeminal schwannoma involving the orbit and lateral wall of the cavernous sinus preoperatively. We performed left frontotemporal craniotomy with superolateral orbitotomy to gain access to the tumor. The tumor was grayish yellow and relatively firm. No intact nerve fibers of the frontal and ophthalmic nerves could be identified, making the diagnosis of the tumor originating from both nerves. Finally, we completely resected the tumor, which was confirmed by postoperative magnetic resonance images. Her postoperative course was uneventful, except for transient diplopia and expected left forehead hypesthesia. The pathology returned to HNST containing schwannoma and neurofibroma with no malignancy. The patient consented to the procedure prior to the surgery. And, the patient consented to the publication of their image.

Microcatheter shaping using intravascular placement during intracranial aneurysm coiling.

Background The selection of a pre-shaped microcatheter or a shaping method must be carefully considered for successful aneurysm coiling. The objective of this report is to verify the use of intravascular placement to establish an appropriate microcatheter shape. Methods Fifteen patients (15 aneurysms) were included in this study because of the predicted difficulty of microcatheter insertion and stabilisation. The SL-10 straight microcatheter was inserted into the parent artery until the tip of the catheter passed through the neck of the aneurysm. After 5 minutes, the microcatheter was pulled out and the shape acquired from intravascular placement was confirmed and compared with the three-dimensional rotational angiography. In addition, the microcatheter tip was steam-shaped for coiling and coil embolisation was performed. A silicone flow model was also used to confirm our findings. The first experiment compared the bend angle in four different microcatheters placed in the model for 5 minutes. In the second experiment, the SL-10 straight microcatheter was placed in the model, and the bend angle was measured at 2.5, 5, 7.5 and 10 minutes to observe the changes in bend angle over time. Results The SL-10 straight microcatheter, in place for 5 minutes, acquired a shape similar to the patient's own vessel. Among the 15 patients included, 13 were treated using an intravascular shaped microcatheter. In the flow model experiments, the SL-10 most easily acquired the vessel shape, and the shape change stabilised after 5 minutes. Conclusion Shaping the SL-10 straight microcatheter using intravascular placement is an effective shaping method for aneurysm coil embolisation.

[Usefulness of image fusion for the treatment guidance of cavernous sinus dural arteriovenous fistula].

Before treating an arteriovenous fistula, it is important to understand its features, particularly the shunting point, sinus form, and drainage route. However, this can often be difficult owing to the large number of vessels that accumulate in the fistula region. In this study, we employed image fusion technology to understand the pathology of cavernous sinus dural arteriovenous fistulas (CSdAVFs) prior to treatment. We performed the following three types of fusions on the workstation: three-dimensional rotation angiography (3DRA) images from different feeding arteries to gain a detailed understanding of fistula architecture and shunting points; three-dimensional computed tomography (3DCT) and 3DRA images for determining the correlation between the skull base bone and the sinus shunt to predict the point of shunt access;and time-of-flight magnetic resonance imaging (TOF MRI) scans and 3DRA source images for investigating retrograde leptomeningeal venous drainage. Compared to individual images, the fused images more effectively provided a detailed understanding of CSdAVFs. Herein, we report our experience with image fusion for CSdAVF and review the relevant literature.

[Thoracocervical giant perimedullary arteriovenous fistula treated with transarterial embolization: a case report].

A 43-year-old woman with progressive gait disturbance and dysesthesia of the limbs and trunk visited our hospital. Upon examination, a thoracocervical giant perimedullary arteriovenous fistula(GPMAVF)was detected. The GPMAVF was fed by both of the highest intercostal arteries and the thyrocervical trunk. The dilated drainage vein widely compressed the spinal cord from the upper thoracic to the cervical regions. Transarterial embolization with n-butyl 2-cyanoacrylate was performed, and the fistula was completely obliterated. The dilated drainage vein was thrombosed, and it decreased in size after treatment. The patient's symptoms and magnetic resonance imaging results significantly improved. We suggest that endovascular treatment is effective for GPMAVFs, given sufficient analysis of the anatomical architecture.

The transventricular preforniceal approach for exophytic chiasmatic/hypothalamic astrocytomas extending into the anterior third ventricle.

BACKGROUND: Surgical treatment of large exophytic chiasmatic/hypothalamic astrocytomas extending into the anterior third ventricle remains a challenging task for neurosurgeons. In particular, when the tumor extends from the chiasmatic region upward to the foramen of Monro, damage to the fornix and other neurovascular structures is a major concern. OBJECTIVE: To describe the technique used in the transventricular preforniceal surgical approach to remove the superior and superoposterior part of the tumor in the third ventricle for treatment of exophytic chiasmatic/hypothalamic astrocytoma. METHODS: The transventricular preforniceal approach was used in two cases of exophytic chiasmatic/hypothalamic astrocytoma. The approach is summarized in 4 procedures: 1) exposure of the anterior horn of the lateral ventricle by the transcallosal approach, 2) identification of the foramen of Monro and the fornix, 3) incision of the septum pellucidum or the wall of the lateral ventricle, in front of the columns of the fornix, and 4) removal of the tumor through the space between the anterior commissure and the columns of the fornix. RESULTS: Because the tumor compressed the foramen of Monro posteriorly and stretched the space between the anterior commissure and the columns of the fornix, the posterosuperior part of the tumor in the third ventricle was successfully removed through the surgical corridor in front of the columns of the fornix. In both cases, tumors were successfully removed using this approach without damaging the fornix and the anterior commissure. Residual tumor was removed using an anterior interhemispheric translamina terminalis approach in a two-stage surgery. CONCLUSIONS: The transventricular preforniceal approach can be applied for removing the superior part of exophytic chiasmatic/hypothalamic astrocytomas, because the space between the anterior commissure and the fornix is stretched by the tumor, providing an appropriate surgical corridor.

Coil embolization for a ruptured posterior cerebral artery aneurysm with vertebrobasilar dolichoectasia.

A 74-year-old man suffered sudden loss of consciousness at home. Computed tomography revealed severe subarachnoid hemorrhage and an unusual posterior cerebral artery (PCA) aneurysm with vertebrobasilar dolichoectasia (VBD). The aneurysm was located in the right hypothalamus. VBD associated with a distal lesion makes endovascular treatment difficult because of the elongation and tortuosity of the access route. However, endovascular coil embolization was successful for the present ruptured PCA aneurysm with VBD.

[Coil embolization of a ruptured posterior cerebral artery aneurysm via the internal carotid artery and a posterior communicating artery: a case report].

A posterior cerebral artery aneurysm is a rare condition. Various surgical approaches have to be considered for operating on these aneurysms because the position of the aneurysm and the surrounding structures restrict the operative field and render the operation difficult. Recently, endovascular treatments for posterior cerebral artery aneurysms have been reported to provide a good outcome. We present a case of a ruptured posterior cerebral artery aneurysm treated with coil embolization. We adopted endovascular treatment because a large vein of Labbé was expected to restrict the operative field. The internal carotid artery and a fetal-type posterior communicating artery (PCoA) were chosen as the access route because of P1 hypoplasty, and a coaxial guiding system was used because of the tortuous access route. The aneurysm was suitably embolized using Guglielmi detachable coils (GDCs). In a case of posterior cerebral artery aneurysm, we report the usefulness of endovascular treatment performed through the internal carotid artery and a fetal-type PCoA.

[Exacerbation of radiation induced meningioma due to hemorrhage after cerebral angiography: a case report].

We report the case of a 34-year-old woman who exhibited acute deterioration in her condition after cerebral angiography for evaluation of a large meningioma. She had undergone surgery and irradiation for a glioma in the right occipital lobe 23 years before this episode. She experienced incapacity at work. On CT and MRI, a large meningioma was detected on the left frontal convexity; this tumor was thought to be radiation-induced. Cerebral angiography was performed to assess the vascularization of the tumor. Her condition began to deteriorate 2.5 h after the cerebral angiography. CT revealed an increase in the mass of the tumor, and a high density area in the tumor. We immediately removed the tumor. Histopathological examination revealed the tumor to be a meningothelial meningioma. New hemorrhagic foci were identified in the tumor. In addition, macrophages containing hemosiderin were detected, and some of the tumor vessels exhibited hyaline degeneration. We suspected that angiography triggered bleeding in the meningioma, which was already predisposed to hemorrhage.

Large hypothalamic hamartoma with calcification and cystic components in an adult--case report.

A 24-year-old female presented with an unusual case of hypothalamic hamartoma manifesting as seizure. Neuroimaging findings were atypical, showing the large tumor (maximum diameter, 50 mm) with a cystic component and calcification. Surgery was performed and histological examination demonstrated heterotopia. Hamartoma should be considered in the differential diagnosis of a suprasellar, non-enhanced mass attached to the hypothalamus. Excessive unnecessary surgery should be avoided, and intraoperative pathological examination may lead to enhanced assessment and better outcomes.

Purely cystic form of choroid plexus papilloma with acute hydrocephalus in an infant. Case report.

Infants with acute hydrocephalus often present with nonspecific neurological signs, and cystic choroid plexus papilloma (CPP) is a very rare cause of acute obstructive hydrocephalus. The authors present the case of a 1-year-old girl who became irritable, started vomiting, and became comatose within a day. Magnetic resonance (MR) imaging revealed a cystic lesion in the third ventricle as well as hydrocephalus. Although the aqueduct appeared to be patent, phase-contrast MR imaging showed no pulsatile flow of cerebrospinal fluid in the ventricles. An emergent endoscopic third ventriculostomy was performed. Endoscopic examination revealed a highly mobile cyst attached by a pedicle to the choroid plexus adjacent to the Monro foramen in the lateral ventricle. The cyst was totally excised during the endoscopic procedure and was subsequently diagnosed as a CPP on the basis of histopathological findings. Purely cystic CPP is a very rare pathological entity; however, when it does occur, it can cause obstructive hydrocephalus which, without rapid diagnosis and surgical intervention, could lead to sudden death.

Unilaterally symptomatic moyamoya disease in children: long-term follow-up of 20 patients.

OBJECTIVE: In unilaterally symptomatic moyamoya disease in children, it remains controversial whether bypass surgery should be performed on the asymptomatic side along with on the symptomatic side. We aimed to verify the validity of our strategy of only performing bypass surgery on the symptomatic side. METHODS: Among 91 pediatric patients with moyamoya disease who underwent bypass surgery in our department between 1980 and 2004, 20 with unilateral ischemic symptoms who were followed for more than 60 months were analyzed in the present study. Initially, we only performed bypass surgery on the symptomatic side for all 20 patients. Among these 20 patients, five developed frequent transient ischemic attacks in the initially asymptomatic side and underwent a second bypass surgery on that side (Group A), eight developed sporadic transient ischemic attacks and were followed up without surgery (Group B), and seven did not experience any ischemic symptoms on the asymptomatic side (Group C). RESULTS: In total, 18 patients progressed well without cerebral infarctions after their last surgery, although some showed deterioration of angiographic stenosis and a transient decrease in the regional cerebral blood flow or cerebral perfusion reserve. One patient in Group A had an intraventricular hemorrhage 5 years after the second operation, and one in Group B had a minor stroke on the initially asymptomatic side. CONCLUSION: In unilaterally symptomatic moyamoya disease, bypass surgery for the asymptomatic side can be delayed until the development of ischemic symptoms, such as frequent transient ischemic attacks.

Retrospective analysis of the surgically treated temporal lobe arteriovenous malformations with focus on the visual field defects and epilepsy.

BACKGROUND: Authors investigate the surgical outcomes of the temporal lobe arteriovenous malformation (AVM) with focus on the visual field deficit and seizure. METHODS: Between 1981 and 2004, we experienced 294 cases of intracranial AVMs. Among the 294 cases, 45 (15.3%) were located in the temporal lobe. Twenty-six of the 45 cases underwent microsurgical excisions of the AVMs. RESULTS: The male-female ratio of 26 surgically treated temporal lobe AVMs was 15:11. The mean age was 34.2 years, ranging from 7 to 63 years. The sites of lesion were classified as polar in 1, dorsal in 2, laterobasal in 15, and mediobasal in 8. The initial symptoms were hemorrhage in 22 and epilepsy in 4 cases. Arteriovenous malformations were totally removed in all 26 patients and there was no surgical mortality. The visual field deficits were identified in 17 of 22 patients with hemorrhage. Massive hematoma cases that needed emergency operation were 5. Visual field deficits improved in only 2 of the 5 patients after surgery. Among the 7 quadrantanopia patients, 3 resulted in hemianopia after surgery. Seven of 22 hemorrhage patients had history of epilepsy. Although one patient had new postoperative epilepsy, the medical controls of the seizure were good in all 8 patients. Four patients underwent AVM excision for epilepsy without hemorrhage. In two patients, seizures disappeared after surgery. The other two patients had typical psychomotor seizures after the total excision of AVMs. CONCLUSIONS: Improvement of visual field deficit due to hematoma was difficult in most cases. Emergency craniotomy for global neurological deterioration due to massive hematoma had improved the visual field deficit in two cases. Although the outcome of seizure associated with hemorrhage was acceptable, the postoperative intractable seizures would remain in cases with epilepsy without hemorrhage. Intraoperative electrocorticography might be requisite for nonruptured temporal lobe AVM cases with epilepsy.

Factors that affect the surgical outcomes of spinal dural arteriovenous fistulas.

BACKGROUND: Authors disclose the factors that affect the surgical outcome of the spinal dural AVFs from the retrospective analysis of 13 cases. METHODS: Thirteen patients with spinal dural AVF underwent microsurgical treatments between 1990 and 2004 at the Department of Neurosurgery, Aso Iizuka Hospital. The mean age was 62 years, and the median time to diagnosis was 38 months (range, 4-120 months). There were 12 men and 1 woman. The clinical features were characterized by spastic paraparesis in all 13 patients and micturition problem in 11 patients. All 13 patients showed the longitudinal extension of the high T2 intramedullary signals in magnetic resonance (MR) image. The microsurgical obliterations of the spinal dural AVFs were performed for all 13 patients because the endovascular treatments were difficult or failed to obliterate the lesions. RESULTS: The durations of the symptoms were not directly correlated to the preoperative neurological conditions and the postoperative outcomes. The patient's age and the preoperative severity of myelopathy affected the postoperative outcomes. The mode of the longitudinal extension of the high T2 intramedullary signals in MR image, rostral or caudal, did not show the statistical significance to the outcome. The poor outcomes were observed in elderly patients and patients with preoperative modified Rankin Scale 4 and 5. A case with multiple spinal dural AVFs is also presented. CONCLUSION: The spinal AVFs are treatable lesions through microsurgery or embolization. The likelihood of favorable outcome was affected by the severity of deficits and the patient's age.

Ruptured saccular aneurysm of a dolichoectatic internal carotid artery in a patient with agenesis of the contralateral internal carotid artery--case report.

A 42-year-old woman presented with very rare cases of ruptured saccular aneurysm of a dolichoectatic internal carotid artery (ICA) associated with agenesis of the contralateral ICA manifesting as sudden onset of severe headache and nausea without neurological deficits. Angiography and three-dimensional computed tomography demonstrated intraventricular hemorrhage with slight subarachnoid hemorrhage and dolichoectasia of the right ICA with agenesis of the contralateral ICA, as well as a saccular aneurysm of the ectatic right ICA. The aneurysm neck was clipped successfully. The patient remained ambulatory with no neurological deficits at discharge 15 days after the surgery. The saccular aneurysm in our case was formed in the dolichoectatic ICA, presumably due to both abnormal hemodynamics and abnormal arterial wall.

[A case of a ruptured anterior communicating aneurysm which was originally the smallest of several unruptured aneurysms].

A 64-year-old male suddenly developed headache and nausea. He had been pointed 3 years before out as having an unruptured basilar artery aneurysm and a right middle cerebral artery aneurysm. Computed tomography (CT) revealed diffuse subarachnoid hemorrhage in the basal cistern and bilateral Sylvian and interhemispheric fissures. Hematomas in the anterior horns of the lateral ventricles and third ventricle were also seen. Angiography revealed an anterior communicating artery aneurysm, which, retrospectively, had been recognized as a small dilatation of artery wall 3 years before. An operation was performed and the anterior communicating artery aneurysm was successfully clipped. The intraoperative findings revealed the aneurysm was the ruptured one. The risk of rupture and surgical indication for unruptured small aneurysms are discussed.