Katsuyuki Asaoka

Microvascular decompression for glossopharyngeal neuralgia: long-term effectiveness and complication avoidance.

OBJECTIVETo establish the long-term safety, efficacy, and durability of microvascular decompression (MVD) for the treatment of glossopharyngeal neuralgia, this study presents the immediate (<6 mo) postoperative and long-term results of a large series of 47 patients with treated with MVD. METHODSOperative reports and hospital charts were analyzed to collect demographic information, clinical presentation, and surgical findings. Surgical results and complications were ascertained by direct patient contact or by contact with the patient’s family or physician if the patient was dead. Long-term (>10 yr) personal follow-up was available for 29 of 47 patients. RESULTSForty-six (98%) of 47 patients experienced complete relief of pain immediately after MVD. Long-term follow-up was available for 29 of these 47 patients (range, 125–211 mo; median, 152 mo, or 12.7 yr), and 28 of these 29 patients continued to be pain-free. Permanent neurological deficits (>6 mo) attributed to the surgery were observed in 5 (11%) of 47 patients. Of these patients, 4 of 5 had mild hoarseness or dysphagia or both, and one had a Grade II/VI facial nerve paresis. CONCLUSIONThis study demonstrates that MVD is a safe, effective, and durable surgical procedure for producing prolonged pain relief in patients with medically intractable glossopharyngeal neuralgia.

Evaluation of application techniques of fibrin sealant to prevent cerebrospinal fluid leakage: a new device for the application of aerosolized fibrin glue.

OBJECTIVE This report evaluates the sealing effects of fibrin sealant applied on the dura mater using different techniques. METHODS Three application methods were studied: a sequential layer method, a simultaneous method using a cannula, and a spray method using a newly developed spray device. The sealing effects of these methods were compared using in vitro histological analysis and a pressure resistance test. The clinical efficacy of the fibrin sealant to prevent water leakage through the dura mater was retrospectively analyzed in a total of 509 patients. The process of absorption of a clinically applied fibrin clot in vivo was examined using surgical specimens. RESULTS The fibrin plate made using the spray method withstood a hydrostatic pressure greater than 200 cm H2O. A scanning electron microscopic study of the fibrin clots showed that the sequential and simultaneous methods produced a fibrin fiber network; in contrast, our spray method formed a dense fibrin tissue in which the fibrin molecules fused together forming stratified laminae. Of the 295 supratentorial craniotomies during which spraying was used, postsurgical cerebrospinal fluid leakage occurred in 9 cases (3.1%), whereas of the 214 craniotomies during which spraying was not used, cerebrospinal fluid leakage occurred in 19 cases (8.9%). Histological examinations of 10 surgical specimens obtained during second craniotomies revealed that the spray-made fibrin clots had been gradually replaced by mature granulation composed of collagenous connective tissue. CONCLUSION The optimal technique for applying fibrin sealant is the spray method that aerosolizes fibrin glue and produces a tough fibrin plate.

Schwannoma of the oculomotor nerve: a case report with consideration of the surgical treatment.

OBJECTIVE AND IMPORTANCE Oculomotor schwannoma is extremely rare. We report a case of oculomotor schwannoma with consideration of its surgical management. CLINICAL PRESENTATION A 64-year-old woman with a history of chronic headache underwent a computed tomographic scan, which revealed a mass lesion in the right prepontine cistern. She had no neurological deficits at admission. INTERVENTION The tumor originated from the right oculomotor nerve. It was subtotally removed, leaving a tiny part attached to the nerve. The nerve trunk was preserved. A pathological examination revealed a schwannoma. Transient right oculomotor nerve palsy occurred postoperatively, but it improved almost completely. CONCLUSION The tumor in the present case was resected, preserving serviceable oculomotor function. However, among 16 patients reported in the literature, all but one developed or maintained severe postsurgical oculomotor nerve palsy. We conclude that surgical resection generally is not indicated for oculomotor schwannomas, excluding large tumors that cause intractable symptoms.

Hemifacial spasm caused by a hemangioma at the geniculate ganglion: case report.

OBJECTIVE AND IMPORTANCE Hemifacial spasm is rarely caused by facial nerve lesions in the temporal bone. Intratemporal facial nerve hemangiomas may initially present as facial spasm. CLINICAL PRESENTATION A 30-year-old woman developed right hemifacial spasm. Physicians observed slight weakness on the right side of her face, in addition to the hemifacial spasm, but routine radiological examinations did not detect any abnormal findings along the course of the facial nerve. Although the patient underwent neurovascular decompression, the spasm persisted postoperatively. Two years after surgery, the right facial palsy progressed. Concurrently, the hemifacial spasm diminished. High-resolution computed tomography demonstrated a small mass lesion expanding the cortex of the right petrosal bone involving the geniculate ganglion of the facial nerve. INTERVENTION The patient underwent a second craniotomy through a subtemporal extradural route, and the tumor was completely removed. A pathological examination demonstrated a cavernous hemangioma. CONCLUSION Routine radiological examinations may fail to detect small intratemporal facial nerve hemangiomas, particularly at the geniculate ganglion. Therefore, when physicians encounter atypical facial spasm, the intratemporal portion of the facial nerve should be carefully examined using high-resolution computed tomography.

Anterior Interhemispheric Approach for Tuberculum Sellae Meningioma

BACKGROUND: The tuberculum sellae meningioma (TSM) arises from the tuberculum sellae, chiasmatic sulcus, and limbus sphenoidale. OBJECTIVE: To retrospectively analyze patients with TSM who underwent surgery via an anterior interhemispheric approach, with special attention to visual outcomes. METHODS: Nine consecutive patients between April 2004 and December 2009 were examined. Visual impairment score (VIS) was used to analyze the visual status of the patients. A VIS is the sum of the scores in specific tables for visual acuity and visual field defects. Visual status was sequentially evaluated in the preoperative period and within 2 weeks of the operation. Any change in the VIS was considered an improvement or deterioration of visual function. All tumors were removed via an anterior interhemispheric approach. Following the wide dissection of the interhemispheric fissure, the tumor was first detached from its origin and debulked with the ultrasonic aspirator starting at the midline. The debulking continued until the arachnoid plane separating the nerve and tumor was visualized. RESULTS: Gross total resection (Simpson I + II) was achieved in all 9 patients. The average VIS was 56.1 in the preoperative period and 26.3 in the postoperative period. Among 9 patients, 8 patients had an improvement of the VIS after surgery. VIS was unchanged in 1 patient, and no patients experienced visual deterioration. Other nonvisual complications, such as rhinoliquorrhea, venous infarction, and permanent anosmia, occurred in 3 patients. CONCLUSION: Despite the small number of patients, a high resection rate and favorable visual outcome support the suitability of this approach for resection of TSM.

Prognostic Factors for Survival in Patients with High- Grade Meningioma and Recurrence-Risk Stratification for Application of Radiotherapy

Background Radiotherapy for high-grade meningioma (HGM) is one of the essential treatment options for disease control. However, appropriate irradiation timing remains under debate. The object of this study is to discern which prognostic factors impact recurrence in HGM patients and to propose a risk-stratification system for the application of postoperative radiotherapy. Methods We retrospectively reviewed 55 adult patients who were diagnosed with Grade II and III intracranial meningioma. Cox regression models were applied to the analysis for impact on early recurrence in HGM patients without postoperative radiotherapy. Results Grade III malignancy (P = 0.0073) and transformed histology (P = 0.047) proved to be significantly poor prognostic factors of early recurrence by multivariate analysis. The other candidates for recurrence factors were Simpson Grade 3–5 resection, preoperative Karnofsky Performance status < = 70%, and MIB-1 labeling index > = 15%. According to these prognostic factors, postoperative HGM patients could be stratified into three recurrence-risk groups. The prognoses were significantly different between each group, as the 3-year actual recurrence-free rates were 90% in low-risk group, 31% in intermediate-risk group, and 15% in high-risk group. Conclusion We propose recurrence-risk stratification for postoperative HGM patients using clinically available factors. Our results suggest that the prognosis for patients with high-risk HGMs is dismal, whereas HGM patients belonging to the low-risk group could have favorable prognoses. This stratification provides us with the criteria necessary to determine whether to apply adjuvant radiotherapy to postoperative HGM patients, and to also help identify potentially curable HGMs without adjuvant radiotherapy.

Intracranial Aneurysms Associated with Aortitis Syndrome: Case Report and Review of the Literature

OBJECTIVE AND IMPORTANCE Aortitis syndrome is a systemic vasculitis of unknown etiology, affecting mainly the major branches of the aorta and leading to stenosis or occlusion. Intracranial aneurysms are rarely associated with this syndrome. Only 15 cases have been previously reported. CLINICAL PRESENTATION A 54-year-old woman with a 10-year history of aortitis syndrome demonstrated nonruptured cerebral aneurysms in the left internal carotid and anterior communicating arteries, with decreased flow in the right internal carotid artery and ipsilateral A1 segment. INTERVENTION The patient underwent clipping of the aneurysms through a left pterional craniotomy and transsylvian approach. CONCLUSION In our review of 16 reported cases, including the present case (13 with ruptured aneurysms and 3 with nonruptured aneurysms), there were 25 saccular aneurysms, and we noted the following clinical characteristics: 1) patient age was 26 to 64 years, with an average of 50.2 years; 2) aneurysms arose predominantly along the course of collateral flow, especially in the vertebrobasilar system (13 of 25 aneurysms, 52.0%); 3) there was a high incidence of multiplicity (7 of 16 cases, 43.8%). These characteristics suggest that increased hemodynamic stress, produced by stenosis or occlusion of the major branches of the aorta and systemic hypertension, plays an important role in the development of cerebral aneurysms in patients with this syndrome.

Occipital-posterior cerebral artery bypass via the occipital interhemispheric approach

Background: The unavailability of the superficial temporal artery (STA) and the location of lesions pose a more technically demanding challenge when compared with conventional STA-superior cerebellar or posterior cerebral artery (PCA) bypass in vascular reconstruction procedures. To describe a case series of patients with cerebrovascular lesions who were treated using an occipital artery (OA) to PCA bypass via the occipital interhemispheric approach. Methods: We retrospectively reviewed three consecutive cases of patients with cerebrovascular lesions who were treated using OA-PCA bypass. Results: OA-PCA bypass was performed via the occipital interhemispheric approach. This procedure included: (1) OA-PCA bypass (n = 1), and combined OA-posterior inferior cerebellar artery and OA-PCA saphenous vein interposition graft bypass (n = 1) in patients with vertebrobasilar ischemia; (2) OA-PCA radial artery interposition graft bypass in one patient with residual PCA aneurysm. Conclusions: OA-PCA bypass represents a useful alternative to conventional STA-SCA or PCA bypass.

Primary Closure of a Cerebrospinal Fluid Fistula by Nonpenetrating Titanium Clips in Endoscopic Endonasal Transsphenoidal Surgery: Technical Note

Postoperative cerebrospinal fluid (CSF) leakage is one of the most common and aggravating complications in transsphenoidal surgery. Although primary closure of the fistula would be the most desirable solution for an intraoperatively encountered CSF leak, it is difficult to achieve in such a deep and narrow operative field. In this article, the authors report endonasal endoscopic applications of no-penetrating titanium clips to repair a CSF fistula following tumor removal. The AnastoClip Vessel Closure System (VCS; LeMaitre Vascular, Boston, MA) was used for closure of a CSF fistula in endonasal transsphenoidal surgery. In all four patients, CSF leakage was successfully obliterated primarily with two to five clips. There was no postoperative CSF rhinorrhea or complications related to the use of the VCS. Metal artifact by the clips on postoperative images was tolerable. Primary closure of the fistula using the VCS was an effective strategy to prevent postoperative CSF leakage in transsphenoidal surgery. Future application can be expanded to reconstruction of the skull base dura via endonasal skull base approaches.

Case Report: Trigeminal Neuralgia Caused by a Minute Meningioma with Hyperostosed Suprameatal Tubercle

Cerebellopontine angle tumors might occasionally provoke trigeminal neuralgia but are usually large enough to be diagnosed radiographically. We present a case of trigeminal neuralgia caused by a very small meningioma covering the suprameatal tubercle that displayed hyperostosis at the entrance of Meckels cave and was not obvious on routine magnetic resonance (MR) images. A 72-year-old woman with intractable trigeminal neuralgia in the left V3 territory was referred to our institution. Preoperative imaging studies revealed that the left trigeminal nerve was medially distorted at the entrance of Meckels cave by a laterally seated bone bulge covered by a minute enhanced lesion. Trigeminal nerve decompression surgery was performed via a retrosigmoid intradural suprameatal approach. We found a small meningioma that had compressed and flattened the trigeminal nerve root at the entrance of Meckels cave, which was grossly and totally removed by suprameatal tubercle resection. There was no vascular compression of the trigeminal nerve root. The trigeminal neuralgia ceased completely after the operation. Accurate preoperative determination of the causative pathologies is essential to achieve adequate surgical results after microvascular decompression for neurovascular compression syndrome. Because conventional MR sequences are inadequate for the precise interpretation of complex neurovascular anatomy in the cerebellopontine angle and such small tumors can be overlooked on routine MR studies, high-resolution thin-slice MR examinations and careful radiological interpretations are required for correct diagnosis and treatment.