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Adverse events in neurosurgery are a serious problem. The approach for seeking solutions for adverse events has shifted from a personal approach to a systemic approach. However, to some extent, preventable morbidity events could be related to personal performance. This study aimed to clarify the impact of personal performance and systematic failure on the occurrence of morbidity and mortality events in neurosurgery patients.All morbidity and mortality conference data stored within our department over a 9-year period were analyzed. There were 4580 admitted patients and 3262 surgical procedures performed. We performed a three-step classification of morbidity and mortality events based on the possibility of prevention, root of the event, and personal or systemic issues.As a result of the first step, 214 preventable and 278 unpreventable events were identified. Of the preventable events, two mortality and 212 morbidity events were analyzed. In the second step, 155 (72.4%), 34 (15.9%), 13 (6.1%), and 12 (5.6%) events were categorized as technical complications, critical events, judgment errors, and human factors, respectively. There were 179 events (83.6%) classified as personal performance issues and 35 events (16.4%) as systemic issues. The ratio of personal performance to systemic issues varied widely, with significant differences among the four categories (P 0.01).Among neurosurgery patients who have preventable morbidity, issues related to personal performance were more frequent than systemic issues. Efforts to improve systems should be unwavering. However, the personal responsibility of neurosurgeons to avoid preventable complications should not be ignored.

We report a 22-year-old man who had abdominal shunt tube migration into colon. He was diagnosed with pilocytic astrocytoma at optic-chiasm to hypothalamus at age of 7, and treated by resection, chemotherapy, and irradiation. He developed hydrocephalus and had multiple ventriculo-peritoneal shunt surgery. At age of 19, he fell in coma due to the subarachnoid and intra-ventricular hemorrhage due to the aneurysm rupture. The ventricle tube was removed, leaving the shunt valve and abdominal tube. The new shunt system was reconstructed at the contralateral side. He was at bed rest after this episode. At age of 20, he had high fever unable to control with antibiotics. The abdominal computed tomogram showed the shunt tube migration in the descending colon. The tube was removed under laparoscopy, and the inflammation was cured. The abandoned peritoneal shunt tube should be removed in patients with high tube migration risks.

Background Although the clinical course of spontaneous intracranial hypotension (SIH) is generally benign, in unusual cases it can result in deterioration of consciousness. The exact mechanisms involved have not always been described in previously reported cases. Case Description Herein we describe the case of a 36-year-old man who presented complaining of orthostatic headache. Brain magnetic resonance imaging depicted typical findings associated with SIH. He initially underwent conservative treatments, but he subsequently began to exhibit deterioration of consciousness. Magnetic resonance imaging revealed progressive brain sagging, swelling of the brainstem, and focal hyperintensity in the left side of the thalamus on diffusion-weighted imaging. The vein of Galen was stretched downwards, creating a narrow angle between it and the straight sinus. We concluded that deep venous hypertension had occurred due to functional venous stenosis. He underwent epidural blood patch twice and ultimately recovered without any neurologic deficits. Conclusions SIH should be recognized as a possible cause of coma as a result of deep cerebral vein stagnation due to severe brain sagging. A change in the vein of Galen/straight sinus angle may be an anatomic marker associated with functional venous stenosis.

Objective Intracerebral hematoma involves two mechanisms leading to brain injury: the mechanical disruption of adjacent brain tissue by the hematoma and delayed neurological injury. Delayed neurological injury involves perihematomal edema (PHE) formation. Infectious complications following intracerebral hemorrhage (ICH) are a significant contributor to post-ICH recovery. We sought to identify a correlation between PHE volumes and infectious complications following ICH. We also sought to explore the clinical impact of this association. Materials and Methods This retrospective study included 143 patients with spontaneous ICH. CT scans were performed on admission, and 3 h, 24 h, and 72 h following admission. Hematoma and PHE volumes were calculated using a semi-automatic method. The absolute PHE volume at each time point and changes in PHE volume (ΔPHE) were calculated. Neutrophil to lymphocyte ratio (NLR) and serum C-reactive protein (CRP) levels were measured from the obtained blood samples. Neurological deterioration (ND) was assessed in all patients. Results Infectious complications were associated with ΔPHE72-24 (P Conclusions This study revealed a correlation between ΔPHE72-24 and infectious complications after spontaneous ICH, which was associated with markers of systemic inflammation. This phenotype linkage is a negative cascade that drives ND.

Background The Delphi consensus statements on the management of germ cell tumors (GCTs) failed to reach agreements on the statement that the cases with (i) pineal and neurohypophyseal bifocal lesion, (ii) with diabetes insipidus, and (iii) with negative tumor markers can be diagnosed as germinoma without histological verification. To answer this, multicenter retrospective analysis was performed. Methods A questionnaire on clinical findings, histological diagnosis, and details of surgical procedures was sent to 86 neurosurgical and 35 pediatrics departments in Japan. Results Fifty-one institutes reported 132 cases that fulfilled the 3 criteria. Tissue sampling was performed in 91 cases from pineal (n = 44), neurohypophyseal (n = 32), both (n = 6), and distant (n = 9) lesions. Histological diagnosis was established in 89 cases: pure germinoma or germinoma with syncytiotrophoblastic giant cells in 82 (92.1%) cases, germinoma and mature teratoma in 2 cases, and granulomatous inflammation in 2 cases. Histological diagnosis was not established in 2 cases. Although no tumors other than GCTs were identified, 3 (3.4%) patients had non-germinomatous GCTs (NGGCTs). None of the patients developed permanent complications after endoscopic or stereotactic biopsy. Thirty-nine patients underwent simultaneous procedure for acute hydrocephalus without permanent complications, and hydrocephalus was controlled in 94.9% of them. Conclusion All patients who fulfilled the 3 criteria had GCTs or granulomatous inflammation, but not other types of tumors. However, no fewer than 3.4% of the patients had NGGCTs. Considering the safety and the effects of simultaneous procedures for acute hydrocephalus, biopsy was recommended in such patients.

This study aimed to assess whether T-lymphokine-activated killer cell-originated protein kinase (TOPK) can be a potent novel biomarker to predict the outcome in patients with primary central nervous system lymphoma (PCNSL). This study enrolled 20 patients who were histologically diagnosed as having diffuse large B-cell type PCNSL between 2005 and 2015. Using surgical specimens, the expression of TOPK and phosphorylated TOPK (p-TOPK) was analyzed on immunohistochemistry. Clinical features such as age, sex, Karnofsky performance status (KPS), ocular involvement, deep brain structure involvement, the number of lesions, chemotherapy and radiation therapy were also collected. Impacts of TOPK/p-TOPK expression on their progression-free survival (PFS) and overall survival (OS) were examined with multivariate analysis. Median PFS/OS were 24.2 and 39.0 months, respectively. On immunostaining, the mean percentage of TOPK-positive cells was 35.5 ± 20.8%, and the mean number of p-TOPK-positive cells was 13.7 ± 15.7 cells/mm2 . The higher expression of p-TOPK was significantly related to multiple lesions (P = 0.003). Multivariate analysis demonstrated that only the higher expression of p-TOPK was an independent predictor to shorten both PFS (P = 0.029; hazard ratio (HR), 5.5; 95% confidential interval (CI), 1.2-25.3) and OS (P = 0.014; HR, 7.7; 95% CI, 1.5-41.3). These findings strongly suggest that p-TOPK may be a potent biomarker to determine the outcome of patients with PCNSL and to develop novel drugs to treat PCNSL.

We report the application of a three-dimensional skull model with vascular structures for occipital expansion in a patient who had developed occipital emissary veins. A 15-year-old boy visited a dentist for orthodontic treatment and was diagnosed with midface hypoplasia. He had undergone a ventriculo-peritoneal shunt at the age of 10 months. On visiting our institution, he was diagnosed with exophthalmos, low visual acuity, reversed bite, and developmental retardation. Moreover, he had sleep apnea and was supported with continuous positive airway pressure at night. Computed tomography and magnetic resonance imaging demonstrated brachycephalus, chronic tonsillar herniation, midface hypoplasia, and well-developed occipital emissary veins. We chose occipital expansion for lowering intracranial pressure and created a three-dimensional skull model with vascular structures and shunt tube. On this model, we wrote scalp incision and craniotomy lines avoiding injury to the veins and shunt tube. The operation was completed using this plan. Patients with syndromic craniosynostosis frequently have developed emissary veins and previous shunt operation. The three-dimensional skull model with vascular structures will be expected to reduce the risks of surgery.

Ultrasound-aided fixation of a biodegradable cranial fixation system called SonicWeld RxThis study included 11 pediatric patients(10 boys, 1 girl), who underwent craniotomy for moyamoya disease, brain tumor, and arachnoid cyst. Their mean age was 6.4 years, ranging from 4 to 10 years. LactoSorbThe time required for screw fixation was significantly shorter in the SonicWeld group(6.5±1.4sec)than in the LactoSorb group(13.4±2.8sec), with p0.05. The quality of fixation strength was adequate in both groups. There were no perioperative complications related to the absorbable fixation device. A 3-D skull CT detected no malposition of the bone flap 3 months postoperatively. There were no scalp complications noted for an average of 21 months.SonicWeld Rx

Radiotherapy is a useful modality for the treatment of brain tumors, but may induce brain degeneration, tumor formation, and vasculopathy in the irradiated field. We describe a rare case of a pediatric patient who presented multiple different types of vascular events consecutively in the irradiated field including lacunar stroke because of occlusion of perforating artery, intraventricular hemorrhage from cavernoma, and subarachnoid hemorrhage because of the rupture of fusiform aneurysm, 6 years after radiotherapy against pilocytic astrocytoma. The life-threatening aneurysm was resected, and its histologic findings revealed the radiation-induced vasculopathy. We should avoid irradiation, and repeat surgical resection for the pediatric cases with pilocytic astrocytoma. Once irradiation was indicated for them, however, we should carefully follow-up not only tumor recurrence but also angiograms to predict any cerebrovascular events.

This study aimed to evaluate the biological features of T-lymphokine-activated killer cell-originating protein kinase (TOPK) in vitro and to assess clinical impact of TOPK on the outcome in patients with malignant glioma. TOPK protein level and TOPK mRNA and protein levels in six glioma cell lines were examined using Western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. Immunohistochemistry was performed to examine their subcellular localization of TOPK. Using surgical specimens from 57 patients with gliomas, TOPK and Ki-67 expressions were examined by immunohistochemistry. Their co-localization was also examined with double immunofluorescence immunohistochemistry. Impacts of TOPK/Ki-67 expression on the overall survival (OS) and progression-free survival (PFS) in 32 patients with glioblastoma multiforme (GBM) were examined, using Kaplan-Meier and Cox proportion hazard models. Immunohistochemistry revealed that approximately 20-30% of glioma cells were positive for TOPK in vitro. TOPK mRNA was identified in all glioma cell lines on RT-PCR. The value of TOPK/GAPDH was 0.27 ± 0.11. TOPK and Ki-67 expressions were significantly higher in GBM patients than in non-GBM patients. A majority of TOPK-positive cells were also positive for Ki-67 and vice versa. Multivariate analysis revealed that a low TOPK expression (≤ 12.7%) was an independent predictor of longer OS (P = 0.0372), and that gross total removal and a low TOPK expression (≤ 12.7%) were independent predictors of longer PFS (P = 0.0470 and P = 0.0189, respectively). The findings strongly suggest biological and clinical importance of TOPK expression in gliomas, indicating a novel therapeutic potential of TOPK inhibitors to treat malignant gliomas.

A 24-year-old woman was diagnosed with a cerebral arteriovenous malformation(AVM)in the right parietal lobe(Spetzler-Martin grade I). The AVM was treated with stereotactic radiosurgery and was observed to have completely disappeared 3 years after radiosurgery. At the age of 35 years, the patient complained of a headache, and was referred to our hospital. A plain CT scan demonstrated a large cyst with niveau formation in the right parietal lobe. Cerebral angiography identified no recurrence of AVM. However, contrast MRI revealed an enhanced lesion on the surface of the cyst. The patient underwent cyst fenestration and total removal of the obliterated nidus through a right parietal craniotomy. Residual blood flow was confirmed in the obliterated nidus during surgery. The postoperative course was uneventful, and the headache was completely resolved. The patient was discharged without any neurological deficits. On pathological examination, a large number of small vessels were observed within the obliterated nidus. Immunohistochemistry demonstrated that these vessels were positive for CD31, CD34, and VEGFR-2, suggesting that endothelial progenitor cells may be involved in occult recurrence, cyst formation, and late bleeding after stereotactic radiosurgery targeting cerebral AVMs.

The authors report a rare case of an intracranial dermoid cyst found in Meckel's cave. A 63-year-old woman developed left oculomotor nerve palsy and was referred to their hospital. Magnetic resonance imaging revealed a cystic lesion in the left Meckel's cave and prepontine cistern, but her symptoms gradually improved during conservative observation. However, three years later she complained of left facial pain in the territory of the second branch of the trigeminal nerve. The left oculomotor nerve palsy exacerbated again. Although her trigeminal neuralgia improved after carbamazepine administration, her oculomotor nerve palsy did not recover. Therefore, she underwent direct surgery through the anterior transpetrosal approach, and the fat-containing tumor cyst was completely resected. The tumor was strongly compressing the left trigeminal nerve and its ganglion in Meckel's cave. After surgery, her facial pain completely resolved and her oculomotor nerve palsy gradually improved. Histological examination revealed that the cyst wall was composed of a single layer of squamous epithelium and contained hair and keratin. A pathological diagnosis of a dermoid cyst was made.

A 76-year-old man presented with a cavernous sinus (CS) dural arteriovenous fistula (AVF) associated with the development of a meningioma without venous sinus occlusion. Initial digital subtraction angiography did not reveal the CS dural AVF, which appeared simultaneously with the enlargement of the meningioma and lead to right oculomotor nerve paresis. In this case, the development of meningioma possibly increased the vascular tumor bed and affected the venous hemodynamic return, thus leading to the dural AVF.

We report a relatively rare case of a disseminated type of nocardiosis without lung involvement. A 75-year-old man developed moderate fever and disturbed consciousness and was admitted to our hospital. Laboratory examinations revealed signs of inflammation. Chest X-rays indicated no abnormalities, but brain MRI showed ring-like enhancement lesions in the right temporal and left frontal lobes. Similar lesions were identified in the left kidney and right leg. The brain lesions were purulent and were surgically irrigated. Gram- and Kinyoun-positive bacteria were identified, and the patient was diagnosed as suffering from a disseminated type of nocardiosis without lung involvement. He was treated with trimethoprim-sulfamethoxazole for over 10 months. The postoperative course was uneventful, and he was discharged without any neurological sequelae two months after surgery. Kinyoun staining was important in early diagnosis and hence providing appropriate therapy for life-threatening nocardiosis.

The efficacy of a neurosurgical navigation system using three-dimensional composite computer graphics (CGs) of magnetic resonance (MR) and computed tomography (CT) images was evaluated in skull base surgery. Three-point transformation was used for integration of MR and CT images. MR and CT image data were obtained with three skin markers placed on the patient's scalp. Volume-rendering manipulations of the data produced three-dimensional CGs of the scalp, brain, and lesions from the MR images, and the scalp and skull from the CT. Composite CGs of the scalp, skull, brain, and lesion were created by registering the three markers on the three-dimensional rendered scalp images obtained from MR imaging and CT in the system. This system was used for 14 patients with skull base lesions. Three-point transformation using three-dimensional CGs was easily performed for multimodal registration. Simulation of surgical procedures on composite CGs aided in comprehension of the skull base anatomy and selection of the optimal approaches. Intraoperative navigation aided in determination of actual spatial position in the skull base and the optimal trajectory to the tumor during surgical procedures.

Subarachnoid hemorrhage (SAH) is usually elicited by cerebrovascular disease and infrequently by brain tumors. A 64-year-old woman presented with SAH with a left petrous meningioma and an unruptured left internal carotid-posterior communicating artery (IC-PcomA) aneurysm. She suffered sudden onset of headache and nausea followed by consciousness disturbance 7 days after onset. Computed tomography (CT) revealed diffuse SAH and a tumor at the petrous portion. Angiography demonstrated a left IC-PcomA aneurysm. Under a diagnosis of a ruptured aneurysm and a coincidental meningioma, we performed neck clipping of the aneurysm. However, intraoperatively we found that the aneurysm was unruptured and we subsequently performed tumor resection. Intraoperatively we could not find the cause of SAH during resection of the meningioma. The histological diagnosis was transitional meningioma with deposition of fibrin on the surface of the tumor. The findings of initial CT and magnetic resonance imaging, and pathological results could not conclude the definitive etiology of SAH in this case.

Donor artery dissection is a known cause of technical failure in microvascular anastomosis. A method for detection and direct repair of donor artery dissection before superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis is described using a high magnification operating microscope (maximum 50.4× magnification). Before STA-MCA anastomosis, the stump of the STA is stained using methylrosaniline chloride (pyoctaninum blue) and is observed under higher magnifications. Microsurgical suturing of the arterial dissection is performed before the anastomosis procedure under the high magnification microscope. This method was used in two patients with symptomatic hemodynamic cerebrovascular occlusive disease. Postoperative angiography revealed good patency and no complications occurred. This method may be useful for detection and direct repair of arterial dissection in small vessel walls before STA-MCA anastomosis.

Idiopathic hypereosinophilic syndrome (HES) is a leukoproliferative disorder that is characterized by sustained overproduction of eosinophils and a trend towards damage to specific organs, usually the cardiovascular system. We report the case of a 76-year-old woman who was affected by idiopathic HES, which had an unusual and rapidly fatal course. Sinus thrombosis in the transverse and sigmoid sinuses was evident on cranial CT and CT angiography. In our review of the English-language literature we were unable to find any previously published direct images of sinus thrombosis in idiopathic HES.

The etiology of dural arteriovenous fistula (AVF) remains uncertain. The authors present a case presenting with anterior fossa dural AVF, which developed after the resection of cerebellar arteriovenous malformation (AVM). The anterior fossa dural AVF, which was not observed on the preoperative angiography, was diagnosed on the follow-up angiography, after the resection of cerebellar AVM. A mechanism underlying the present case is not clearly understood. To the best of our knowledge, some cases of dural AVF secondary to craniotomy have been reported. It is postulated that intracranial vascular anomaly should be analyzed after the surgery.

A 19-year-old woman with a 3-year history of schizophrenia suddenly began to vomit, and rapidly developed a coma an hour after the onset of vomiting. A brain CT scan showed diffuse brain edema with compression of the ventricles. Laboratory tests showed a low serum sodium concentration of 117 mmol/L. She died 67 h after the onset of the first symptom. A postmortem examination showed diffuse swelling of the brain with bilateral uncal and tonsillar herniations. Histologically, no necrotic, hemorrhagic or encephalitic changes were seen. However, microvacuolar changes with lymphocytic infiltration were found in the venous walls (media and adventitia) mainly in the basal ganglia, thalamus and brainstem. To our knowledge, this is the first demonstration of venous alterations in fatal hyponatremic brain edema. These changes may have participated in the exacerbation of the brain edema due to functional disturbance of venous drainage.

Background Brainstem venous congestion is a rare but serious complication of the CS-dAVF (cavernous sinus dural arteriovenous fistual). Case Description A 71-year-old woman presented with right abducens nerve palsy. Brain MRI showed a solitary lesion in the right upper pons. Cerebral angiogram revealed the right CS-dAVF with retrograde venous drainage into the cerebellar cortical veins and the anterior pontomesencephalic vein. The patient was treated with stereotactic radiosurgery, resulting in complete resolution of the pontine lesion and the neurologic symptom. Conclusion A solitary brainstem lesion can be caused by CS-dAVF as a rare complication. Careful diagnosis and treatment are important to avoid permanent neurologic deficits.

Objective: The surgical anatomy of structures surrounding the anterior clinoid process (ACP) was examined in 39 cadavers to enable safe performance of selective extradural anterior clinoidectomy. Methods: The lateral portion of the optic canal (OC) at the end of the orbit was defined as point A, and the lateral margin of the dural insertion into the superior orbital fissure (SOF) as B. A vertical line from A to the lateral margin of the ACP was assumed to define a crossing, defined as C. Distances between A and B, C and B, and C and A were measured. The length and width of OC and the optic strut were also measured. Results: The mean distances between A and B, C and B, and C and A were 11.8, 8.9 and 6.3 mm, respectively. The mean length and width of OC were 8.9 and 5.7 mm, and those of the optic strut 5.4 and 2.4 mm, respectively. Conclusion: We propose a modified, efficient procedure for selective extradural anterior clinoidectomy, as follows. Drilling is started from the point approximately 9 mm posterior to the lateral margin of the dural insertion into the SOP, and pointed medially in the direction with a right angle to the lateral margin of the ACP. After drilling about 6 mm to reach the lateral border of the OC, unroofing of the OC is carried out to remove the ACP en bloc by fracturing of the optic strut. Using the present procedure, the distance of drilling of the lesser wing of the sphenoid bone is minimized.

Homocystinuria is a congenital metabolic disorder, and has been known as life-threatening risk factor of vascular disease including ischemic stroke. We report a case of cerebral infarction due to homocystinuria. The patient was a 21-year-old woman exhibiting left hemiparesis and a previous history of ectopia lentis. Magnetic resonance imaging showed multiple fresh infarctions in the right frontal and temporal lobes, basal ganglia, corona radiata, and internal capsule. The right common carotid angiogram demonstrated complete occlusion at the origin of the right internal carotid artery. Further investigation clarified increased level of serum methionine and homocysteine and urinary homocystin due to cystathionine beta-synthase deficiency. Homocystinuria was diagnosed as the cause of cerebral infarction. The patient was treated by low methionine diet and administration of folic acid, cobalamin, and aspirin. It should be recognized that some patients with homocystinuria are missed in the neonatal screening for congenital metabolic disorders. Recent studies indicated that the homocysteinemia is one of risk factors of ischemic stroke in the general population as well as in the patients of homocystinuria. We recommend metabolic screening for homocystinuria, when treating a juvenile patient with ischemic stroke of unknown etiology.

Superficial siderosis of the central nervous system (SS) is a rare clinical syndrome due to repeated intracranial hemorrhage. We report a case of SS occurring 19 years after subtotal removal of a non-functioning pituitary adenoma. The patient was a 37-year-old female, exhibiting progressive bilateral sensory neural hearing loss and cerebellar ataxia. T2 weighted magnetic resonance imaging demonstrated a rim of low intensity signal on the cerebellum, brain stem, and sylvian fissure. Immediate diagnosis based on characteristic symptoms and MRI findings is important for the prevention of irreversible progression of SS.

We report a case of hydrocephalus due to posterior cranial fossa subdural effusion. The patient was a 4-year-old boy, presenting headache and nausea, with a medical history of viral meningitis 2 months before. Cerebrospinal fluid provided no evidence of infection, and symptoms caused by increased intracranial pressure gradually deteriorated, although glycerol infusion was effective temporarily. Computed tomography revealed marked ventriculomegaly with subdural effusion in the right posterior cranial fossa. The subarachnoid space in the posterior fossa was very tight, and the cerebellum and brain stem were compressed anteriorly. Magnetic resonance imaging demonstrated stenosis of the aqueduct and foramens of Luschka and Magendie. The cerebeller tonsil was dislocated inferiorly, indicating impending herniation, so an emergency operation was performed. Ventriculoperitoneal shunt was undertaken after implantation of an Ommaya reservoir for the posterior fossa subdural effusion. The patient's postoperative course was uneventful, and the symptoms were improved. Although hydrocephalus and subdural effusion following viral meningitis is rare, neuroimaging studies such as CT and MRI should be examined when a young child suffers from symptoms of increased intracranial pressure.

A 61-year-old woman presented with progressive dementia over a period of 4 months. Computed tomographic (CT) scans and magnetic resonance (MR) imaging showed 2 meningiomas located at the left parasagittal region and the left sphenoid ridge. These tumors had distinct MRI findings; the left parasagittal tumour showed a clear peritumoral CSF space without brain oedema, but the sphenoid ridge tumour was large with marked peritumoral oedema. Total excision of these 2 tumours was attempted with favourable clinical improvement and histological studies revealed meningiomas of different histological types. The left parasagittal tumour was a fibrous meningioma and the left sphenoid ridge tumour was an anaplastic meningioma with typical brain invasion. These tumours showed a MIB-1 staining index of 1% and 30%, respectively. There was also a difference in the immunohistochemical findings for neurofibromin (NF1 product) expression; the left parasagittal tumour expressed neurofibromin but the left sphenoid ridge tumour lacked neurofibromin expression, suggesting an NF1-gene mutation. This case may be a rare example of the simultaneous occurrence of meningiomas with distinct genotypes.

Elongation and bending of the basilar artery are frequently observed in both normal and pathological subjects. However, their mechanism of generation remain unclear. In the present study, we measured basilar arteries in patients and normal subjects using magnetic resonance angiography (MRA) and estimated the relationships between these anatomical changes and some factors such as age, sex and vertebral artery dominance. A total of 510 subjects underwent MRA. Basilar artery length (BAL), bending length (BL), or side of bending of basilar artery was estimated on the plain images including the basilar artery in two groups with and without vertebral union. BAL was longer in males than in females (P = 0.0009) and correlated with age (P0.0001) in the population with vertebral union, while BL did not differ between genders and was not correlated with age in this population. Both BAL and BL were longer in subjects with vertebral artery dominance than in subjects with equivalent-sized vertebral arteries in the population with vertebral union (P0.0001 and P = 0.0005). No difference in the frequency of basilar artery bending was observed between males and females and no correlation was observed between the frequency of basilar artery bending and ages in subjects without vertebral artery union. A significant negative correlation between the side of bending of the basilar artery and dominant side of vertebral arteries was found for group of all patients (P0.0001). BAL growth may mainly depend on aging, and the presence of vertebral artery dominance may contribute to the growth of BAL while BL growth may depend on vertebral artery dominance mainly in the contralateral direction.

Objective We have developed a simple and easy modification of the orbitozygomatic approach using one-piece pedunculated craniotomy. This modification prevents atrophy of the temporal muscle, resulting in temporal fossa depression and atrophy of the free bone graft resulting in the occurrence of bone pits along the line of the craniotomy. Methods The key points of this modification are as follows. The scalp flap is elevated in the plane between the superficial and deep layers of the temporal fascia. The temporal muscle is dissected from the temporal plane by performing subperiosteal elevation with intact insertion to the superior temporal line of the temporal muscle, which results in the creation of a subperiosteal tunnel beneath the temporal muscle. The one-piece fronto-orbitozygomatic bone flap is hinged on the temporal muscle. Results After the surgeons had received full training in the procedures and anatomic findings related to this craniotomy in 10 cadaveric heads, surgery was performed for paraclinoid or parasellar tumors in five patients. Although temporary pulsatile exophthalmos occurred after surgery in one patient, no craniotomy-related complications occurred during or after surgery. Because the bone flap is fragile at the frontozygomatic suture, fixation with a small titanium plate was required in three of five patients at the end of the operation. All patients were pleased with the cosmetic results of surgery during a minimum follow-up period of 6 months. Conclusion The modifications described in this article reduce the risk of atrophy of the temporal muscle and improve the cosmetic results without limitation of operative exposure.