Search

Background The availability of magnetic resonance imaging (MRI) has led to an increase in the detection of pituitary incidentaloma (PI). However, there are no robust data on surgical treatment of PI on which to base therapeutic recommendations. This study was performed to investigate the significance of surgery for asymptomatic nonfunctioning pituitary adenoma (NFPA) among PIs. Methods A total of 180 patients that underwent tumor resection of pituitary adenoma via the transsphenoidal approach between 2005 and 2017 were reviewed. Thirty-three consecutive patients with subjectively asymptomatic NFPA were included in this study. Our surgical indications for asymptomatic NFPAs were categorized as follows: macroadenoma with optic chiasma compression (group A, n = 14), solid tumor ≥2 cm in size (group B, n = 7), and tumor growth on follow-up MRI (group C, n = 12). The clinical outcomes were analyzed accordingly. Results Seven patients (50%) in group A showed subjective improvement of visual function after tumor resection even though they had no complaints preoperatively. On the other hand, no changes occurred in any cases in group B or group C. Although there were no critical complications in this series, the incidence of nonnegligible nasal complications was relatively high (24.2%) and may decrease the patient's quality of life. Conclusions Surgery should be recommended for asymptomatic NFPA with optic chiasma compression to improve visual outcome. On the other hand, immediate intervention for other asymptomatic NFPA to reduce the likelihood of the appearance of tumor-related symptoms remains questionable considering its invasiveness to the nose.

The older adult population in developed countries is rapidly increasing, as is the number of older adults with cervical spondylosis. Previous studies on the surgical outcomes of older adults with cervical spondylosis have reported contradictory results. This study aimed to compare the surgical outcomes in adults with cervical spondylosis who were

In patients with carotid bifurcation stenosis co-existing with ipsilateral intracranial artery stenosis, combined treatment with carotid artery stenting (CAS)/carotid endarterectomy (CEA) and extracranial-to- intracranial (EC-IC) bypass can be a useful option to prevent future ischemic stroke events. EC-IC bypass requires a sufficient antegrade flow in the ipsilateral external carotid artery. However, standard CAS/CEA occasionally lead to external carotid artery occlusion. Herein, we present a case of successful one-stage endovascular revascularization of both the antegrade internal and external carotid artery flow using the carotid T-stent technique for carotid bifurcation stenosis co-existing with ipsilateral middle cerebral artery stenosis.

It is generally accepted that dopamine agonists (DA) represent the first-line treatment for most patients with prolactinoma, and patients become candidates for surgical intervention when DA is contraindicated. Surgical indication for cystic prolactinoma remains controversial. This study was performed to investigate the significance of surgery for cystic prolactinoma. A total of 28 patients that underwent transsphenoidal resection of prolactinoma between February 2004 and May 2016 were reviewed. Five consecutive patients with cystic prolactinoma were included in this study. Our surgical strategy for cystic prolactinoma was categorized as follows: first, when the purpose of surgical resection was normalization of the prolactin level, aggressive resection was performed; second, when volume reduction was essential to relieve the visual symptoms and headache, internal decompression was performed followed by DA therapy. The clinical outcomes were analyzed accordingly. All cystic prolactinoma were resected via the transsphenoidal approach without any complications, and all symptoms including visual impairment and hypogonadal activity were finally relieved combined with medication. Surgery for cystic prolactinoma could be a better option. Transsphenoidal surgery is relatively safe to remove the cystic prolactinoma, additionally it can normalize the prolactine level and achieve adequate and rapid decompression of optic chiasm. The risk of transsphenoidal surgery is highly dependent on the skill of the surgeon and treatment decision for cystic prolactinoma needs to be individualized for each patient.

Background and Purpose Few studies have described regression of white matter hyperintensities (WMHs); however, no studies have described their recurrence or fluctuation. Thus, we aimed to study the course of WMHs on fluid-attenuated inversion recovery (FLAIR) magnetic resonance image (MRI) after extracranial-intracranial (EC-IC) bypass surgery and its correlation with the clinical outcome. Methods We enrolled perioperative FLAIR MRIs of 12 patients with WMHs who underwent EC-IC bypass surgeries because of ischemic-vascular stenosis with postoperative improvement of the cerebral blood flow confirmed by 123 I-iodoamphetamine single-photon emission computed tomography. Correlation between WMHs and cerebral blood flow was confirmed by perioperative single-photon emission computed tomography and diffusion-weighted imaging MRI. The WMHs were assessed visually with meticulous volumetric grading. Depending on postoperative changes among different grades, the WMHs course was determined to be improved, fluctuating, worsened, or unchanged. A statistical analysis was performed on the course of WMHs over time. Results Imaging analysis was done with FLAIR MRI in 12 patients. The course of WMHs over time was 41.7% improvement, 33.3% fluctuation, 16.7% unchanged, and 8.3% worsening of the deep WMHs. After unilateral bypass surgery, 80% of the improved WMHs occurred bilaterally. Among patients with improved clinical outcomes, 16.7% showed improvement and 33.3% showed fluctuation, whereas in patients with unchanged clinical outcomes, 25% showed improvement of their WMHs on follow-up FLAIR MRIs. Conclusions This study might be considered the first step to find a relationship between successful EC-IC bypass surgeries and the course of ischemic WMHs. It could also open the door for further studies to make more solid conclusions.

Surgery for ventrally seated thoracic tumors requires an anatomically specific approach that is distinct from cervical or lumbar spinal cord surgery as the narrower spinal canal of the thoracic spinal cord makes it sensitive to surgical procedures. However, reports describing this operative technique are few. To obtain a wide operative field and minimize thoracic spinal cord retraction, we employed a posterolateral transpedicular approach in ventral-located tumors and investigated the efficacy and limitations of this technique. Eighteen patients with lesions (meningioma or neurinoma) located in the ventral intradural thoracic region were surgically treated between 2009 and 2014. The relationship among the clinical outcome, tumor location, and postoperative spinal alignment was analyzed. Postoperative neurological function improved in all patients, namely those with meningioma (p = 0.012) and schwannoma (p = 0.018). One patient who underwent removal of two facet joints suffered a postoperative compression fracture. Removal of two facet joints and pedicles resulted in a worsening of spinal alignment (p = 0.03), while this was not the case for the removal of one facet joint and pedicle (p = 0.72). This case series clarified the benefits of the posterolateral transpedicular approach for resection of ventral intradural extramedullary tumors. Removal of one pedicle and facet joint seems to be more beneficial.

Background In reverse bypass that used a naturally formed "bonnet" superficial temporal artery, intraoperative volume flow measurement quantifies flow augmentation after revascularization, confirms flow preservation, and identifies inadvertent vessel compromise. Case Description A 75-year-old man presented with transient ischemic attacks attributed to right internal carotid artery stenosis. He underwent successful reverse bypass via a naturally formed "bonnet" superficial temporal artery middle cerebral artery bypass. As the result of proper intraoperative volume flow evaluation, a successful reverse bypass was achieved. Conclusions Modification of the intraoperative stroke risk and prediction of the long-term patency after reverse bypass can be achieved by meticulous intraoperative blood flow evaluation.

OBJECT The nonpenetrating titanium clip has been successfully used in peripheral arterial bypass surgery. The purpose of this study was to evaluate the leakage pressures and patterns of nonpenetrating titanium clips using a simple model that mimicked spinal surgery. In addition, the authors describe their surgical experience with these clips and the follow-up results in 31 consecutive patients. METHODS The authors compared nonpenetrating titanium clips and expanded polytetrafluoroethylene (ePTFE) sutures in relation to the water pressure that could be tolerated by sutured ePTFE sheets, and the leakage pressure patterns were determined. The changes in leakage pressures at 5 minutes, 30 minutes, and 12 hours were examined when the clips and sutures were used in combination with the mesh-and-glue technique in an in vitro study. Thirty-one patients underwent spinal intradural procedures using nonpenetrating titanium clips to suture the dura maters using the meshand-glue technique, involving fibrin glue and polyglycolic acid-fibrin sheets. RESULTS A significant difference was apparent between the ePTFE suture group and the nonpenetrating titanium clip group, with the latter showing a leakage pressure that could be sustained and was 1508% higher than that of the former (p = 0.001). In relation to leakage patterns, the nonpenetrating titanium clips did not make any suture holes in the ePTFE sheet and fluid leakage occurred between the clips, whereas fluid leakage was associated with the pressure elevation that occurred at the suture holes made by the ePTFE sutures. Of the 31 patients who underwent spinal intradural procedures using nonpenetrating titanium clips, 1 (3.2%) experienced cerebrospinal fluid (CSF) leakage postoperatively. No other complications—for example, allergic reactions, adhesions, or infections—were encountered. CONCLUSIONS The interrupted placement of nonpenetrating titanium clips enables dural closure without creating any holes. These clips facilitate improvements in the initial leakage pressure and reduce postoperative CSF leakage following spinal surgery. The authors conclude that it is very beneficial to suture the spinal dura mater using nonpenetrating titanium clips given the anatomical characteristics of the spinal dura mater and the fact that the clips do not create suture holes.

Introduction: Cerebral edema is the most frequent adverse event of BCNU wafer, which is used as local chemotherapy of malignant glioma. However, predictive factor of this event is unknown. Moreover, there is no consensus about cerebral edema and perioperative seizure, which is often observed in glioma. Here, we report risk factor of cerebral edema with BCNU placement and relationship with perioperative seizure in malignant glioma cases. Material and Method: Thirty-one case of adult malignant glioma who underwent BCNU placement in our institute between March 2013 to March 2019 were investigated. The patients were dichotomized to two groups; patient with postoperative transient cerebral edema (CE+ group) and patient without postoperative transient cerebral edema (CE- group). Result: Postoperative cerebral edema associated with placement of BCNU was observed in 9 out of 31 patients (29%). Tumor malignancy was significant parameter for postoperative cerebral edema (p=0.003). Other factors such as, age, gender, laterality, tumor location, primary or recurrent, number of BCNU wafers, duration of recurrence were not significant for postoperative cerebral edema. Seizure was seen in 14 patients (45%), and cerebral edema was not significant parameter for seizure. Tumor malignancy was significant parameters for postoperative cerebral edema. Tumor malignancy was significant parameters for seizure (p=0.0004). Although postoperative seizure was observed in 4 patients (44%) with CE+ group, neither maximum volume (mean 61.1 ml) nor change ratio (mean 354%) of FLAIR-high-intensity region were not related with postoperative seizure. Conclusions: Tumor malignancy was important factor for patients who underwent placement of BCNU wafer with postoperative cerebral edema and seizure. On the other hand, there were no relationship between postoperative cerebral edema and perioperative seizure in patients treated with BCNU wafer.

Background There is still a controversy for low-flow extracranial–intracranial or high-flow extracranial–intracranial bypass with proximal occlusion in the treatment of unclippable giant internal carotid artery aneurysms. Case Description A 61-year-old woman presented with a 1-month history of double vision. Neuroimages revealed an unclippable giant internal carotid artery aneurysm located from the cavernous sinus to proximal site of the posterior communicating artery. Ipsilateral A1 of the anterior cerebral artery was hypoplastic, and posterior communicating artery was patent. Intraoperative proximal test occlusion at cervical internal carotid artery under neurophysiological monitoring, instead of preoperative balloon test occlusion, was performed to assess whether low-flow bypass was sufficient. The monitoring was unchanged during test occlusion, and the aneurysm was successfully trapped without high-flow bypass. Neither ischemic lesion nor neurologic deficits were found postoperatively. Conclusions Intraoperative proximal test occlusion is useful to decide on the surgical procedure of revascularization in patients with unclippable internal carotid aneurysm.

INTRODUCTION Although 95% of meningiomas are benign tumor (WHO grade I), they rarely exist malignant transformation. It is well known that WHO II or III meningiomas rapidly grow and recurrent frequently. However, there are no common sense about duration of malignant transformation between previous reports. Here we report a case of anaplastic meningioma which showed malignant transformation in 18 years. CASE The patient was 77-year-old man. He was pointed out as having a 20-mm mass in the left occipital convexity at brain checkup 19 years before. After 6 months, the mass was totally removed (Simpson grade I) at previous hospital. Histopathological diagnosis revealed meningioma with psammoma body, whose Ki-67 index was below 1 %. Postoperative course was good and periodic follow up was abandoned. The patient presented with consciousness disturbance and right hemiparesis after 18 years from the first operation. CT scan showed a 30-mm mass with intratumoral hemorrhage and perifocal edema in the left occipital lesion. Tumor removal was performed. The border of the tumor was clear and the macroscopic view was compatible with meningioma at intraoperative findings. The tumor was removed as much as possible, but partially remained which were extended to superior sagittal sinus (Simpson grade III). Histopathological findings were anaplastic meningioma with sarcoid change, whose Ki-67 index was 70%. His neurological abnormality improved postoperatively. DISCUSSION In the previous report, anaplastic meningioma is a rare tumor, which is 1% of whole meningioma. The rate of malignant transformation is reported 12–38%. The cause of malignant transformation is reported to be radiation therapy, mechanical stimulation by surgical manipulation, viral infection, and loss of chromosome. Although recurrence rate is low at total resection of meningioma, there rarely exists malignant transformation after a long period of time like our case.

OBJECTIVEThe aim of this study was to predict postoperative facial nerve function during pontine cavernous malformation surgery by monitoring facial motor evoked potentials (FMEPs).METHODSFrom 2008 to 2017, 10 patients with pontine cavernous malformations underwent total resection via the trans–fourth ventricle floor approach with FMEP monitoring. House-Brackmann grades and Karnofsky Performance Scale (KPS) scores were obtained pre- and postoperatively. The surgeries were performed using one of 2 safe entry zones into the brainstem: the suprafacial triangle and infrafacial triangle approaches. Six patients underwent the suprafacial triangle approach, and 4 patients underwent the infrafacial triangle approach. A cranial peg screw electrode was used to deliver electrical stimulation for FMEP by a train of 4 or 5 pulse anodal constant current stimulation. FMEP was recorded from needle electrodes on the ipsilateral facial muscles and monitored throughout surgery by using a threshold-level stimulation method.RESULTSFMEPs were recorded and analyzed in 8 patients; they were not recorded in 2 patients who had severe preoperative facial palsy and underwent an infrafacial triangle approach. Warning signs appeared in all patients who underwent the suprafacial triangle approach. However, after temporarily stopping the procedures, FMEP findings during surgery showed recovery of the thresholds. FMEPs in patients who underwent the infrafacial triangle approach were stable during the surgery. House-Brackmann grades were unchanged postoperatively in all patients. Postoperative KPS scores improved in 3 patients, decreased in 1, and remained the same in 6 patients.CONCLUSIONSFMEPs can be used to monitor facial nerve function during surgery for pontine cavernous malformations, especially when the suprafacial triangle approach is performed.

Arterial injury related to stent strut is rare during stent-assisted coil embolization. The patient underwent stent-assisted coil embolization for a right middle cerebral artery aneurysm. At this time, the parent arterial injury at M1 portion of the middle cerebral artery resulted in subarachnoid hemorrhage. The arterial penetration caused by the stent strut was repaired with wrap-clipping. Postoperative angiograms demonstrated the complete obliteration of the arterial injury. The patient was discharged without neurological deficits. Neither recurrence nor stenosis was observed after surgery. Wrap-clipping is a useful procedure to repair the arterial injury due to the stent strut.

Background Inflammatory lesions of the pituitary gland including hypophysitis are poorly understood, and it is difficult to make a correct diagnosis on the basis of only clinical and radiologic findings. Case Description An otherwise healthy 68-year-old man presented with sudden onset of headache, visual impairment, and pituitary insufficiency. Magnetic resonance imaging revealed a pituitary mass with cystic component showing changing intensity on follow-up images. Also, changing density of the lesion was demonstrated on computed tomography over a short period of time. These findings suggested a hemorrhagic lesion, and a preoperative diagnosis of pituitary apoplexy associated with a preexisting pituitary adenoma was made on the basis of clinical and radiologic findings. In the endoscopic endonasal approach for tumor resection, there was neither hematoma nor adenoma. Histopathologic diagnosis was lymphocytic hypophysitis. Conclusions To the best of our knowledge, this is the first case report of hypophysitis with radiologic signal changes over a short period. Vigilant attention regarding the clinical diagnosis of such rare entity is paramount.

Venous anastomosis is one of the most difficult techniques in vascular neurosurgery. We present a simple technique of end-to-end venous anastomosis for reconstruction of accidentally injured vein. A venous catheter was used for the stent during the end-to-end anastomosis. The venous catheter as the stent facilitated confirmation of the ostium of the vein. The venous end-to-end anastomosis was successfully performed. Accidental venous injury can be reconstructed with the present simple technique.

This surgical video emphasizes the nuances that needed to overcome daunting challenges of clipping of paraclinoid carotidophthalmic and superior hypophyseal artery (SHA) aneurysms. To avoid hazardous manipulations, scarifying the ipsilateral SHA under visual evoked potential (VEP) guidance can be done without risk of postoperative visual decline. This technique is associated with better visual outcome.1 A 66-yr-old woman presented with gradually enlarging right paraclinoid carotidophthalmic and SHA aneurysms. The relationship between those aneurysms and the critical neurovascular structures made us facing a daunting challenge to preserve the visual function. To preserve the patency of the ophthalmic artery (oph.A), endovascular intervention was abandoned and a direct clipping surgery was selected. Following VEP settings, exposure of the cervical internal carotid artery for proximal control and right frontotemporal craniotomy, a subfrontal approach was used. To get adequate accessibility and safe maneuverability, the anterior clinoidectomy and unroofing of the optic canal were completed, then, the falciform ligament and the distal dural ring were carefully opened. Under VEP guidance, the oph.A and SHAs were temporarily occluded. VEP had been stable under repeated occlusions. The carotidophthalmic aneurysm was clipped with preservation of the oph.A. Besides, 1 ipsilateral SHA was sacrificed to achieve complete clipping of the SHA aneurysm. Final indocyanine green videoangiography confirmed obliteration of the paraclinoid aneurysms and patency of the oph.A, the other SHA and the tiny arterioles around the optic nerve. The postoperative course was uneventful. There was no evidence of postoperative visual disturbances. The patient has consented to the submission of the case report to the journal.

Anterior cerebral artery (ACA)-related ischemia is a rare entity in patients with atherosclerosis. Some surgical treatments are reported to date. We present the modification of intracranial-intracranial and intracranial-extracranial bypasses for symptomatic bilateral ACA steno-occlusive disease. The A3-A3 bypass followed by the superficial temporal artery-ACA bypass using the ipsilateral free superficial temporal artery graft is useful without harvesting of the radial artery. Bilateral ACA steno-occlusive induced ischemia can be treated with tailored bypass procedures.

Background A case of dural arteriovenous fistula (dAVF) developed after radical neck dissection for lymph node metastasis 2 years after oral surgery for tongue cancer. Methods The patient was asymptomatic during follow-up visits with no evidence of metastasis on follow-up CT scan of the neck. However, diagnostic angiography showed left internal carotid artery (ICA) stenosis and dAVF involving the posterior meningeal artery and transverse sinus at the left posterior fossa with cortical venous reflux (Cognard type III). They were treated with carotid stenting and surgery, respectively. Results The postoperative course was uneventful. Follow-up angiography revealed obliteration of the dAVF. Conclusion This was a rare case of iatrogenic dAVF after surgical ligation of venous outflow during radical neck dissection. The surgical plan is presented along with a literature review regarding the development of iatrogenic dAVFs induced by direct surgical trauma. © 2015 Wiley Periodicals, Inc. Head Neck, 2015

Surgically treated patients with arteriovenous malformations (AVMs) are considered cured when the postoperative angiogram proves complete resection. However, despite no residual nidus or early draining vein on postoperative angiogram, rare instances of AVM recurrence have been reported in adults. In this paper, the authors present a case of a 24-year-old woman with asymptomatic double recurrence of her cerebral AVM after angiographically proven complete resection. To the authors' knowledge, this patient represents the first case with double de novo asymptomatic recurrence of Spetzler-Martin grade I AVM. Also, she represents the first case with unique AVM criteria in each recurrence.

During microsurgical procedures, manipulations are often performed using a foot switch while the surgeon stands on one foot. This position can easily result in body axis instability and greater musculoskeletal loading. To support the surgeon's posture, we have developed a tool called the "Surgeon's Body Support Device." The objective of this study was to determine the efficacy of this device by analyzing surgeons' kinematics and musculoskeletal loading during simulated operations undertaken while standing. Fourteen surgeons volunteered to perform simulations of surgery while standing. To analyze motion kinetics and musculoskeletal loading with and without this device, a three-axis accelerometer and surface electromyography (SEMG) sensors were attached to the subjects. Compared with not using the supportive device, the axis of the surgeon's body was significantly more stable when the support device was used (P = .001). The evenness of motion also tended to be superior when the device was utilized (P = .009). Simulations performed using the device significantly reduced the musculoskeletal loading on the ventral side of the left foot by 70 % compared with simulations performed not using the device (P = .001). Data from SEMG sensor placed on the right hand, which performs the surgical manipulations, indicated that simulations performed using the device generated approximately 10 % of the musculoskeletal load generated when the device was not used (P = .001). The Surgeon's Body Support Device appears to improve maneuverability and reduce musculoskeletal loading during simulated surgical procedures undertaken while standing.

The surgical strategies and methods used to treat dumbbell-shaped tumors located in the lumbar-foraminal region are controversial. Although a total facetectomy and combined intra- and extraspinal canal approach provide a wide operative field, facet fusion is required, which can be rather invasive. Here, we report a successful removal of a lumbar dumbbell-shaped schwannoma using a combined laminoplastic laminotomy with Wiltse’s paraspinal surgical approach. This was performed under an operating microscope without a complete facetectomy, fusion, and posterior fixation. Briefly, we treated two patients with lumbar foraminal tumors, both dumbbell-shaped schwannomas located in the intra- and extradural portion. After a laminoplastic laminotomy, the intradural tumor was removed. The tumor located at the extracanalicular site was removed after drilling the pars interarticularis of the lamina, which was performed to enlarge the intervertebral foramen via Wiltse’s paraspinal surgical approach. During surgery, facetectomy with posterior fixation was not needed to remove the intraforaminal component. There was no lumbar instability or complication after surgery. Our results suggest that a combined posterior laminoplastic laminotomy and Wiltse’s paraspinal surgical approach is useful and less invasive for treating patients with lumbar foraminal tumors.

Cervical spinal neurinomas are benign tumors that arise from nerve roots. Based on their location, these tumors can also take the form of a dumbbell-shaped mass. Treatment strategies for these tumors have raised several controversial issues such as appropriate surgical indications and selection of surgical approaches for cervical dumbbell-shaped spinal neurinomas. In this report, we review previous literature and retrospectively analyze cervical spinal neurinoma cases that have been treated at our hospital. Surgical indications and approaches based on tumor location and severity are discussed in detail. Thus, with advances in neuroimaging and neurophysiological monitoring, we conclude that appropriate surgical approaches and intraoperative surgical manipulations should be chosen on a case-by-case basis.

Background Migraineurs exhibit pain hypersensitivity throughout the body during and between migraine headaches. Migraine is classified as a central sensitivity syndrome, typified by fibromyalgia showing widespread pressure hyperalgesia determined by a tender point. This study was performed to examine whether: 1) there is a subgroup of episodic migraineurs with widespread pressure hyperalgesia during and between attacks; 2) if such a subgroup exists, what is the prevalence and what is the difference between groups with interictal widespread hyperalgesia and acute allodynia regarding the demographic and clinical characteristics of migraine. Methods This was a cross-sectional study. A total of 176 consecutive episodic migraineurs and 132 age- and sex-matched controls were recruited. The presence of widespread pressure hyperalgesia was investigated using manual tender point survey. To classify a subject’s response as widespread pressure hyperalgesia, the cutoff value for responders was defined as the positive tender point count below which 95% of controls responded. Results Based on the number of positive tender points in controls, the cutoff value of tender point count for pressure hyperalgesia responders was 7. Of the 176 subjects, interictal widespread pressure hyperalgesia and acute allodynia were observed in 74 (42%) and 115 (65.3%) patients, respectively. Univariate analysis indicated that risk factors associated with interictal widespread pressure hyperalgesia were female gender, younger age at migraine onset, higher frequency of migraine attacks, severe headache impact, cutaneous allodynia and depression. Multivariate logistic regression analysis confirmed that independent risk factors associated with interictal widespread pressure hyperalgesia were female gender, higher frequency of migraine attack and younger age at onset. Conclusion Interictal widespread pressure hyperalgesia was common (42%) in the episodic migraineurs and was associated with younger age at onset, female gender, and higher frequency of headache, but not duration of migraine illness. Presence of interictal widespread pressure hyperalgesia is assumed to be an indicator of genetic susceptibility to migraine attacks. We expect that a tender point count, as an alternative to quantitative sensory testing, will become useful as a diagnostic indicator of interictal hyperalgesia in migraineurs to predict susceptibility to migraine attacks and to permit tailored treatment. Electronic supplementary material The online version of this article (10.1186/s10194-017-0824-0) contains supplementary material, which is available to authorized users.

It is often difficult to definitively diagnose dural lesions with hypertrophy as they exhibit nonspecific imaging findings and clinical symptoms. Most cases require histopathological evaluation with surgical intervention (such as biopsy). However, complications related to surgical interventions remain as matter of concern. Herein, we analyzed and verified the significance of surgery in 39 patients with hypertrophic dural lesions who were histopathologically diagnosed with surgical interventions. Specimens of dural lesions were obtained successfully, and it was possible to make a definitive diagnosis for each case based on histopathological findings. All patients tolerate the procedures well, and there were no evidences of surgery-related complications during surgical approach to the dura mater. Preoperative and pathological diagnoses varied in eight cases. Our results indicate that histopathological evaluation is important for distinguishing diseases showing dural hypertrophy even if surgical invasiveness is concerned. Neurosurgeons should not hesitate to perform surgery for management of dural lesions with hypertrophy in order to achieve accurate diagnosis.

The development of hydrocephalus following aneurysmal subarachnoid hemorrhage (SAH), a well-known sequela of the SAH, was firstly documented by. Many investigators have well established the relationship between SAH and hydrocephalus, and two stages of the hydrocephalus have been recognized: acute one, observed immediately after onset, and chronic one. The incidence of post-SAH hydrocephalus has been reported to be 9–67%, and this wide range may be caused by the variation of the defining criteria of hydrocephalus as well as the effect of the different treatments for ruptured aneurysm. Several mechanisms have been proposed to explain the development of hydrocephalus following SAH. Cerebrospinal fluid (CSF) dynamics is of importance for the development of the hydrocephalus. Hydrocephalus in patients with SAH may be induced mainly by obstructive mechanisms after the sudden increase in the arterial blood into the subarachnoid space lead to resist CSF outflow or block CSF circulation within the ventricular system in acute stage and also may be caused mainly by absorptive problems attributable to impaired CSF absorption in chronic stage. Acute hydrocephalus is more frequent in patients with poor clinical grade and higher Fischer Scale scores. The insertion of external ventricular drainage (EVD) has been the standard care in the management of the acute post-SAH hydrocephalus, purposing primarily immediate improvement of the clinical condition, leading more suitable objection for curative surgical or endovascular intervention. Chronic hydrocephalus influences cognitive deficits and poorer neurological outcome and requires permanent CSF diversion.

Long titanium aneurysm clips have recently been released. In the present study, comparative study of long titanium and cobalt alloy clips was performed. Two kinds of Sugita long clips (straight clips of 25- and 35-mm blade length) made of titanium and cobalt alloys were tested by measuring the closing force, the anti-scissoring torque, and the maximum opening width. There were some differences between the two materials. In the 25-mm blade length clip, closing force and maximum opening width of titanium alloy clip were greater than those of cobalt alloy clip. By contrast, the anti-scissoring torque of 35-mm blade length titanium clip was stronger than that of the cobalt. The long titanium clips would have equivalent endurance to long cobalt clip and are safe for clinical use., Article, NEUROLOGIA MEDICO-CHIRURGICA.54(3):176-179(2013)

Object Several materials, such as polyethylene glycol (PEG) hydrogel and fibrin glue, have been used to seal dural incisions after brain and spinal surgeries. Although the use of PEG sealant is gaining popularity, it can be associated with postoperative cerebrospinal fluid leakage and infection. However, the reasons for this association are currently unknown. The present study aimed to investigate the effects of PEG sealant and fibrin glue on wound healing and brain damage in vivo. Methods Oval-shaped bone defects and dural defects were created bilaterally over the parietal lobes of 22 Japanese white rabbits. The dural defects were covered with 0.5 ml of fibrin glue on one side and 0.5 ml of PEG sealant on the other side. Dural regeneration and brain damage were investigated in each harvested brain and dura mater using light microscopy. Results Dural regeneration was more effective in the presence of fibrin glue than it was with PEG sealant (p = 0.014). Of the 22 rabbits, 11 showed thick (Grades ++ and +++) dural regeneration by 28 days postsurgery in the hemisphere where fibrin glue was used, whereas Grade +++ dural regeneration was not observed in the PEG hydrogel hemisphere, and only 4 rabbits showed Grade ++ regeneration. Abscess and granulation formation also tended to be more severe when PEG hydrogel sealant was used. No Grade ++ granulation/abscess formation was observed with fibrin glue, and Grade + was only observed in 13 of 22 rabbits. Conversely, with PEG hydrogel sealant, only 2 rabbits did not show granulation/abscess formation, and Grade +, ++, and +++ granulation/abscess formation was observed in 8, 7, and 5 rabbits, respectively. The extent of cortical damage was significantly greater in rabbits with abscesses and granulations, compared with rabbits without these lesions (p = 0.007). Conclusions Dural regeneration tended to occur more rapidly with fibrin glue, whereas granulation was more likely with PEG hydrogel sealant, which led to postoperative complications. Histological analysis indicated that PEG hydrogel sealant inhibited the normal tissue healing process and that outcomes were improved by the use of fibrin glue.

Cerebral perfusion monitoring is an important component of hyperacute stroke treatment. Arterial spin labeling (ASL) perfusion magnetic resonance (MR) imaging provides a noninvasive method of cerebral perfusion observation. Rapid changes in cerebral perfusion were demonstrated in two patients admitted one hour after onset of hyperacute stroke who underwent recombinant tissue plasminogen activator (rt-PA) treatment. Serial MR images and ASL images were taken on admission and after rt-PA administration. Cerebral blood flow (CBF) values were obtained using the CBF workstation and analysis software. Interpretable ASL images were taken in both patients. Perfusion deficits were consistent with symptoms and/or MR angiography imaging abnormalities. Delayed arterial transit effect was present in one patient; serial imaging showed improvement of CBF after rt-PA treatment in both patients. ASL perfusion MR imaging can provide rapid noninvasive multislice imaging in hyperacute ischemic stroke, and can depict early perfusion deficit and quantify regional CBF concomitantly., Article, NEUROLOGIA MEDICO-CHIRURGICA. 53(4):213-216 (2013)

The authors report on a new method for removing dumbbell-shaped spinal tumors that avoids the risk of postoperative cerebrospinal fluid (CSF) leakage. Adequate visualization of the intra- and extradural components of the tumor is achieved with the use of separate dural incisions. First, the dura mater is opened along the dural theca to provide adequate visualization of the intradural portion of the mass; then, a second incision is made along the nerve root to remove the extradural component. Meticulous suturing is essential in intradural lesion cases; however, the dura mater is usually thin and fragile in such cases. During suturing with a needle and thread, the dura mater can become lacerated proximal to the needle holes and result in CSF leakage. In the authors' technique, instead of using a needle and thread, nonpenetrating vascular clips were used to close the dural incisions. When operating on dumbbell-shaped spinal tumors, the authors found that the “separate-dural-incision method” was preferable to the conventional T-shaped dural incision method because no dural defects occurred after the intradural procedure and meticulous dural closure with vascular clips was achieved. The authors conclude that the novel separate-dural-incision method for removing dumbbell-shaped tumors and the use of nonpenetrating vascular clips permits reliable dural closure, prevents postoperative CSF leakage, and promises good postoperative clinical results.

Background Paraclinoid carotid aneurysm is widely treated with coil embolization. However, all paraclinoid carotid aneurysms cannot be obliterated by the endovascular approach.

Although closing force of cobalt alloy clip is well studied, there is only little information of titanium alloy clip available in the literature. In the present study, we examined and compared closing forces of various types and points of cerebral titanium and cobalt aneurysm clips for cerebral aneurysms. Straight, temporary, bayonet, angled, and fenestrated titanium or cobalt alloy clips were tested by measuring the closing forces at various points along their blade length. Closing forces of all the tested clips linearly increased from tip to base of clip blades. Sugita Titanium II clips had bigger closing forces than Elgiloy clips in all type clips except for the temporary clips. The closing forces of Sugita Titanium II and Yasargil titanium clips were similar in straight permanent type clip although there were some differences in closing forces between other types of Sugita and Yasargil clips. Our data showed that the closing forces differed depending not only on manufacturers but also on materials and shapes., Article, NEUROSURGICAL REVIEW. 36(1):133-137 (2013)

Although the cerebral aneurysm clip "scissoring" phenomenon is known to occur due to twisting of the aneurysm clip blades during surgery, there have been few previous studies of scissoring. In the present study, we examined the in vitro endurance of clip twisting to assess clip scissoring. To evaluate the clip-scissoring effect, we measured torque at the rotating aneurysm clip head (Sugita and Yasargil clips) using our own manufactured product. A silicon sheet 1 mm thick was clipped at several depths (3, 6, and 9 mm), and the clip head was mechanically rotated. Straight and fenestrated clips of titanium alloy were used in the present study. Cobalt alloy straight clips were also examined. Preliminary experiments indicated that torque values during clip head rotation dropped when the blades crossed. In addition, torque values before blade crossing showed resistance to slippage of the blades. Torque values of both Sugita and Yasargil clips were directly proportional to the blade depth. There were no differences between straight and fenestrated Sugita clips. Although the torque was greater in cobalt alloy than titanium alloy Sugita clips, the torque values of Yasargil cobalt and titanium clips were identical. We found some differences in torque values during clip head rotation between Sugita and Yasargil clips. Based on the results of twisting experiments, scissoring is likely to occur when occluding the neck of the aneurysm only with the tips of long clip blades., Article, NEUROSURGICAL REVIEW. 35(2):219-224 (2012)

Involuntary movement is an uncommon manifestation of moyamoya disease. We describe a 12-year-old boy who suffered from involuntary movement after the first surgery but it improved dramatically after the second surgery. Initially, the patient underwent an encephalo-duro-arterio-myosynangiosis on the right side and encephalo-duro-periostealsynangiosis on the bifrontal side, which ameliorated his motor weakness in his left upper extremity. However, involuntary movement appeared in his right upper extremity. Secondly, the patient underwent encephalo-duro-arterio-myo-periostealsynangiosis on the left side. Thereafter, the patient’s involuntary movement completely resolved. The involuntary movement might occur due to the unequal distribution of the blood flow in the basal ganglia.

Background Histopathologic studies of dural arteriovenous fistulas (dAVFs) are important for clarifying the pathogenesis. We present a case of Cognard type IV dAVF with detailed histopathologic studies in correlation with radiologic and intraoperative findings. Case Description An otherwise asymptomatic 53-year-old man presented with chronic headache. Neurologic examination revealed no abnormalities. Neuroimaging and cerebral catheter angiographic studies disclosed a left frontoparietal dAVF close to the middle third of the superior sagittal sinus, fed by the left superficial temporal and bilateral middle meningeal arteries and draining into ectatic cortical and dural veins. No evidence of superior sagittal sinus thrombosis or occlusion was seen. Intraoperatively, the parietal branch of the left superficial temporal artery penetrated the skull vault to feed the fistula; arterialized cortical and draining dural veins were also noted. Complete obliteration of the dAVF with removal of the affected dura mater was achieved safely. Histopathologic studies in serial sections documented a shunt point between the dural artery and the dural vein within the dura mater and a draining point between the dural and cortical veins. Conclusions On the basis of clinical, angiographic, intraoperative, and histologic findings in our case, we strongly excluded acquired etiologies.

Objective: The incidence rate of aneurysmal subarachnoid hemorrhage (SAH) in the elderly is increasing. Although endovascular coiling has become a major form of treatment for SAH in elderly patients, not all ruptured aneurysms can be managed with an endovascular approach. Conventional surgical clipping still plays an important role in SAH treatment. The present study was performed to assess the outcome in patients older than 75 years of age in whom ruptured aneurysms were treated by clipping surgery. Methods: This retrospective study included patients 75 years of age or older who underwent clipping surgery for ruptured cerebral aneurysms between 1988 and 2009. Age, gender, preoperative grade, Fisher grade, size, and location of the ruptured aneurysm were compared between cases showing favorable and unfavorable outcomes. Results: A total of 333 patients were analyzed. There were significant differences in preoperative grade, Fisher grade, and location of the aneurysm between the favorable and unfavorable outcome groups. In multivariate logistic regression analysis, independent predictors of unfavorable outcome were poor grade and ruptured anterior cerebral artery aneurysm, but not age of 80 years or older. Conclusions: Advanced age did not represent a risk factor for poor outcome of clipping surgery in elderly patients. Although coil embolization has been shown to be a useful form of treatment, direct surgery should also be considered., Article, NEUROLOGICAL RESEARCH. 33(8):853-857 (2011)

BACKGROUND AND IMPORTANCE: Formation of cerebral de novo aneurysms (CDNAs) is rare, and the pathogenesis remains obscure. We analyzed factors involved in formation of CDNAs and suggest guidelines for follow-up of patients. CLINICAL PRESENTATION: We retrospectively reviewed intracranial aneurysms at our institute and published reports from 1964 to 2008. Eleven patients were found with CDNAs, and 138 patients were collected from the published literature. We assessed the clinical characteristics, such as sex, size, and site of CDNA, past history, and time to occurrence of CDNAs. Of 11 patients, 10 were female and 1 was male; the mean age of the first onset was 53 years (range, 25-69 years). The mean time between first aneurysms and CDNAs was 10.6 years (range, 3-29 years). The most common site of occurrence was anterior circulation. One patient experienced contralateral occurrence, and 2 patients changed from anterior to posterior circulation CDNAs. Six (54.5%) patients had a history of arterial hypertension. Results from analysis of the whole series from the literature revealed that the risk of rupture increased with a previous history of hemorrhage. Contralateral occurrence of CDNAs was related to previous location, and multiplicity, whereas the occurrence of anterior to posterior changes of CDNAs and shorter interval only correlated with an older age group. CONCLUSION: Although the formation of CDNAs is rare, several factors may contribute to its occurrence. Female patients with a history of arterial hypertension were at a higher risk for CDNA occurrence. We recommend follow-up imaging studies within 10 years after the initial aneurysms; therefore, at least 50% of CDNAs can be found before rupture.

A 14-year-old girl who presented with an endodermal cyst manifesting as severe neck and shoulder pain along with vesicorectal disturbances. Cervical magnetic resonance imaging showed a slightly enhanced intradural cyst at the C6-7 level in the ventral side of the spinal canal, with significant dorsal shortening and thinning of the spinal cord. Anterior corpectomy was chosen because of the dorsal effacement of the spinal cord. The cyst wall was subtotally removed to avoid damage to the normal spinal cord. After cyst removal, the iliac bone and an anterior cervical plate were used for anterior fusion. Postoperatively, her pain subsided without neurological deficits. The histological diagnosis was endodermal cyst. The cyst did not recur during a follow-up period of 18 months. Endodermal cysts are rare congenital lesions of the spine lined by endodermal epithelium. The natural history of this lesion is unclear, and the surgical strategy for the approach route and the extent of removal of the cyst wall remain controversial. We suggest that the anterior approach may allow a safer and more effective surgical route for the treatment of ventrally located endodermal cyst compared to the posterior approach.

Direct surgery remains important for the treatment of superficial cerebral arteriovenous malformation (AVM). Surgical planning on the basis of careful analysis from various neuroimaging modalities can aid in resection of superficial AVM with favorable outcome. Three-dimensional (3D) magnetic resonance (MR) imaging reconstructed from time-of-flight (TOF) MR angiography was developed as an adjunctive tool for surgical planning of superficial AVM. 3-T TOF MR imaging without contrast medium was performed preoperatively in patients with superficial AVM. The images were imported into OsiriX imaging software and the 3D reconstructed MR image was produced using the volume rendering method. This 3D MR image could clearly visualize the surface angioarchitecture of the AVM with the surrounding brain on a single image, and clarified feeding arteries including draining veins and the relationship with sulci or fissures surrounding the nidus. 3D MR image of the whole AVM angioarchitecture was also displayed by skeletonization of the surrounding brain. Preoperative 3D MR image corresponded to the intraoperative view. Feeders on the brain surface were easily confirmed and obliterated during surgery, with the aid of the 3D MR images. 3D MR imaging for surgical planning of superficial AVM is simple and noninvasive to perform, enhances intraoperative orientation, and is helpful for successful resection.

This study investigated the outcome of clipping surgery for ruptured aneurysms in patients older than 80 years of age. From 1988 to 2011 data were retrospectively reviewed, and 196 patients treated with clipping obliteration for aneurysmal subarachnoid hemorrhage were identified. Patients were divided into two age groups of 80–84 and ⩾85 years old. The Glasgow Outcome Scale score was assessed at discharge and classified as favorable (good recovery or moderate recovery) or unfavorable (severe disability, vegetative state, or dead). Radiological and clinical characteristics were compared between the two groups. A favorable outcome was achieved in 106 (54.1%) of the 196 patients. Preoperative grade and Fisher grade were significantly associated with unfavorable outcome, but age was not. Based on logistic regression analysis, poor preoperative grade and ruptured anterior cerebral artery aneurysm were the predictors of unfavorable outcome, but advanced age (⩾85 years old) was not. Advanced age itself did not affect the outcome of the elderly patients who underwent clipping surgery for aneurysmal subarachnoid hemorrhage.

Object The aim of this study was to evaluate cerebral aneurysm clips, and to know in more detail the characteristics of currently available clips in the 3-T magnetic field. Methods According to the protocol recommended by the American Society for Testing and Materials (ASTM), the authors conducted quantitative evaluation for displacement force and qualitative evaluation for torque in 52 aneurysm clips and 48 samples of raw materials in the 3-T environment. Results The largest displacement force occurred near the bore opening, and the force was directed to the isocenter. Deflection angles of all objects in this study were within 45°. The translational force in the peripheral position in the bore was larger than that in the center, and the translational force in the magnetic field was proportional to the weight of the objects. The proportion coefficients varied depending on the metallic materials. In the titanium alloy, the deflection angle was also detected to be approximately 2°, although no response was observed in titanium in a previous report. This behavior was similar to that of the Elgiloy and Phynox materials in the 1.5-T environment. No difference was observed among the groups of shapes (straight, bent, and fenestrated). The amount of torque that occurred was dependent on the clip's or material's loop and bent shape. The torque on the titanium was perpendicular to the torque on the other materials (which was perpendicular to the magnetic field). Conclusions Care must be taken with patients near the bore opening while moving them to the center of the magnet's bore on the MR imaging table. Although all the clips examined in this study met the ASTM requirements, the titanium alloy clips are preferable in the 3-T environment for safety's sake. Suitably sized clips should be selected for the aneurysm size, because the translational force increases proportionally to the object's weight.

The purpose of this study was to evaluate cases of subarachnoid hemorrhage (SAH) from ruptured anterior (dorsal) paraclinoid aneurysms. Anterior paraclinoid aneurysms are defined as aneurysms arising from the anterolateral wall of the proximal internal carotid artery without any relationship to an arterial branch. Between 1991 and 2008, a total of 159 patients with 169 paraclinoid aneurysms were treated at the Shinshu University Hospital and its affiliated hospitals. A retrospective analysis was carried out using charts, operation records, operation videos, and neuroimagings. Twenty six patients had anterior paraclinoid aneurysm. Six patients presented with SAH. Three aneurysms were saccular and the others were blister-like aneurysms based on operative findings. Neck laceration or premature rupture frequently happened during the clipping surgery even though the aneurysm was saccular type. The treatment of a ruptured anterior paraclinoid aneurysm is quite difficult. Trapping and bypass would be recommended for such fragile aneurysms., Article, NEUROSURGICAL REVIEW. 34(1):49-54 (2011)

Background Symptomatic Tarlov cysts are extremely rare, and there is no consensus regarding their optimal surgical management. Here, we encountered a patient with a symptomatic sacral Tarlov cyst and reviewed the appropriate literature. Case description A 40-year-old male presented with right lower extremity pain and hypoesthesia in the right S2 dermatome. The lumbosacral MR demonstrated a right S2 Tarlov cyst compressing the S2-S3 perineural sheaths. After the patient underwent microscopic cystectomy with obliteration of the subarachnoid connection to the cyst, the patient's symptoms resolved. Here, we reviewed our operative approach, and others proposed in the literature for the surgical management of these lesions. Conclusions Here, we present a 40-year-old male who was symptomatic from a right S2 Tarlov cyst compressing the S2-S3 perineural sheaths and successfully underwent microscopic cystectomy with obliteration of the subarachnoid connection. Additionally, the appropriate Tarlov cyst literature was reviewed.

A 45-year-old woman presented with a rare case of metastatic cauda equina tumor from breast cancer without spinal column or brain metastasis. She had undergone resection of breast cancer 4 years previously. She presented with a 2-month history of severe low back pain. Magnetic resonance imaging showed a well-enhanced intradural extramedullary mass at the L1 level without other intradural lesions. At surgery, the tumor was partially removed to preserve the nerve root function under electrophysiological monitoring. The histological diagnosis was adenocarcinoma. The tumor was located in the subarachnoid space, suggesting hematogenous metastasis from the breast cancer. Postoperatively the pain subsided and no neurological deficit occurred. She underwent adjuvant therapy and rehabilitation. Cauda equina tumors may be relatively progressive regardless of imaging findings and clinical symptoms, so preoperative systemic investigation should be conducted, considering the possibility of metastatic tumor. A comprehensive therapeutic strategy involving adjuvant therapy after surgery is important to establish, considering the preservation of postoperative nerve function.

The radial artery and saphenous vein have been used as a useful free graft for neurosurgical revascularization surgery. Potential disadvantages of the radial artery compared with the saphenous vein include relative shortness, spasm, and functional occlusion. To compensate for the short length of the radial artery graft, the radial artery and the superior thyroid or occipital arteries were connected end-to-end. This method was applied in 3 cases of unclippable aneurysms, achieving adequate revascularizations. There were no complications related to this procedure. Radial artery graft bypass using the superior thyroid or occipital artery is a simple, safe, and useful method for cerebral revascularization.

Background: Ultrasonic surgical aspirators have been used mainly for removing brain tumors. Because of their longitudinal and torsional tip, they are used for cutting the bone structures in spinal surgery installing a scalpel-type tip. The purpose of this report is to describe the effectiveness and surgical pitfalls of an ultrasonic bone curette in laminoplastic laminotomy and hemilaminotomy. Methods: We present 12 patients who underwent laminoplastic laminotomy and hemilaminotomy. We used a SONOPET UST-2001 ultrasonic bone curette with HB-05S handpieces (M and M Co, Ltd, Tokyo, Japan). After a tumor was removed, titanium plates were used for the laminoplastic laminotomy and hemilaminotomy. The technical advantage of an ultrasonic bone curette and procedure-related complication were examined. Results: There were no major procedure-related complications such as cord injury. Wound infection and subcutaneous fluid collection caused by cerebrospinal fluid leakage did not occur for reconstruction of posterior bony structure. In 1 patient with calcified dura mater associated with tumor, dural tear occurred. The width of the tip was narrow enough for resected laminae to be fused postoperatively, and spinal instability did not occur in all cases. Conclusion: The scalpel-type ultrasonic bone curette is useful for cutting bone and effective for reconstruction of the laminae. Laminotomy with an ultrasonic bone curette is safe and minimally invasive. To prevent dural tear, we recommend drilling laminae to make the bone thin as the first step, followed by cutting the remaining laminae using a bone curette especially in cases with calcified or tense dura mater., Article, SURGICAL NEUROLOGY. 72(5):470-475 (2009)

Object The ophthalmic artery (OphA) usually arises from the intradural internal carotid artery (ICA), and the extradural origin has also been known. However, the interdural origin is extremely rare. The purpose of this paper was to clarify the origin of the OphA in patients with a paraclinoid aneurysm in the ICA based on intraoperative findings. Methods The authors retrospectively examined 156 patients who underwent direct surgical treatment for 166 paraclinoid aneurysms during a 17-year period. Based on intraoperative findings, 119 ophthalmic arteries were analyzed with respect to their origins. Results The OphA originated from the intradural ICA on 102 sides (85.7%), extradural on 9 (7.6%), and interdural on 8 (6.7%). Although the extradural origin might be recognized preoperatively, it was difficult to distinguish the interdural origin of the OphA from the intradural one. Conclusions The incidence of the interdural origin was 6.7% and was not as rare as the authors expected. Neurosurgeons should know the possible existence of the interdural origin of the OphA to section the medial side of the dural ring.