Safety and efficacy of the endoscopic transsphenoidal transclival approach performed using direct cortical stimulation for pontine cavernous malformations.

OBJECTIVE: Surgical treatment of brainstem cavernous malformations (CMs) is challenging. Surgery using the endoscopic transsphenoidal transclival approach (eTSTCA) is reported as a useful alternative for ventral brainstem CMs. However, CMs located in the ventral midline of the brainstem are rare, and only a small number of case reports on these CMs treated with the eTSTCA exist. The efficacy and safety of the eTSTCA have not yet been fully examined. METHODS: A retrospective analysis was performed for 5 consecutive patients who underwent surgery via the eTSTCA for treating ventral pontine CMs. RESULTS: The average maximum CM diameter was 26.0 mm (18-38 mm). All patients underwent MR-diffusion tensor imaging, which confirmed that the corticospinal tract (CST) deviated posteriorly or laterally to the CM. Direct brainstem cortical stimulation was performed to localize the CST before making the cortical incision. After the excision of the CM, the cavity was filled with artificial CSF to make an aqueous surgical field (wet-field technique) for observing the tumor cavity and confirming complete hemostasis and resection. Total removal was achieved in all patients. The preoperative modified Rankin Scale score was 3 in 3 patients and 4 in 2 patients, whereas it was 1 in 2 patients and 0 in 3 patients 3 months after surgery. Postoperative CSF leakage was observed in 1 patient, and transient abducens nerve palsy was observed in 1 patient. No other intra- or postoperative complications were observed. CONCLUSIONS: MR-diffusion tensor imaging and direct brainstem cortical stimulation were useful to ascertain the proximity of the CST to the CM. The endoscope provides a clear view even underwater, and it was safe and effective to observe the entire CM cavity and confirm complete hemostasis without additional retraction of the brainstem parenchyma, including the CST. The eTSTCA provides a direct access point to the lesion and may be a safer alternative treatment for patients whose CST deviates laterally or posteriorly to the CM.

Endoscopic Trans-Mini-Cylinder Biopsy for Intraparenchymal Brain Lesions.

OBJECTIVE: The biopsy procedure is intended to obtain an adequate specimen volume from the targeted area while ensuring minimal damage to the normal brain. We performed navigation-guided endoscopic biopsy using a small-diameter cylinder to reduce the invasiveness of the biopsy procedure and ensure a sufficient amount of tissue is collected. We examined whether it is possible to reduce brain tissue injury by using a small-diameter cylinder and improve safety and effectiveness by using an endoscope to directly observe the lesion and achieve hemostasis. METHODS: Patients who underwent endoscopic biopsy surgery using a 6-mm-diameter cylinder for intraparenchymal lesions were enrolled in this study. Postoperative hematoma formation and the extent of trajectory scarring were assessed. RESULTS: Fifty-two procedures performed on 51 patients were analyzed in this study. Postoperative neurological deterioration was not observed in any patient. A pathological diagnosis was made for all patients. Postoperative computed tomography revealed no hematoma after 49 procedures and a small hematoma after 3 procedures, and no patients required additional treatment. A postoperative trajectory scar less than 5 mm in diameter was observed after 30 procedures, a scar of 5-10 mm was observed after 19 procedures, a scar larger than 10 mm was observed after 3 procedures at 1 week after surgery, and 40, 6 and 0 scars were observed at 3 months after surgery. CONCLUSIONS: Endoscopic biopsy using a small-diameter cylinder is a possible alternative biopsy technique for intraparenchymal lesions. This surgical technique is useful, especially in patients at risk of hemorrhagic complications.

Case of a Pregnant Woman with Capillary Hemangioma of the Parasellar Region.

Here we report a rare case of capillary hemangioma (CH) in a 28-year-old woman suffering from gradual worsening diplopia at 28 weeks of pregnancy. Magnetic resonance imaging (MRI) showed a mass lesion (about 3 cm in diameter) in the right parasellar region. We decided to observe as she was pregnant, and had no symptoms other than right abducent nerve palsy. Fortunately, her symptoms did not worsen until delivery. Computed tomography, enhanced MRI, and angiography after delivery revealed that the lesion was highly calcified and vascularized. A dorsum sellae meningioma or highly calcified pituitary adenoma was suspected and the endoscopic transsphenoidal approach was used for tumor removal. The postoperative course was uneventful. The histological diagnosis was CH. Intracranial CHs or CHs of skull are rare vascular tumors. These tumors are reportedly more common in female patients and may change in size in adults according to menstrual cycle and pregnancy. Only six cases, including that of the present study, were diagnosed during the perinatal period. Some of them experienced rapid symptom progression and tumor growth in their course; thus, we should pay further attention to pregnant or peripartum patients with brain tumor, suspected hemangiomas.

Importance of Hydrostatic Pressure and Irrigation for Hemostasis in Neuroendoscopic Surgery.

Recently neurosurgical operations have been carried out with water irrigation such as endoscopic third ventriculostomy and tumor resections in ventricles. Water irrigation is one of several published methods that promote hemostasis; however, not enough experimental evidence exists on its efficacy. In this study, we investigate whether hydrostatic pressure and persistent irrigation promote hemostasis in neuroendoscopic surgery. We dissected tails of 12-16-week-old C57BL/6 male mice at 5 mm proximal from the tip and checked for bleeding times under dry and wet conditions at pressures of 0 cmH2O, 10 cmH2O, 15 H2O, and 20 cmH2O without persistent irrigation to bleeding point and 10 cmH2O with persistent irrigation. We then examined the dissected edge with hematoxylin-eosin staining and measured the size of vessels. The average bleeding time of each group is as follows: dry: 203.4 sec, wet: 164.4 sec, 5 cmH2O: 138.6 sec, 10 cmH2O: 104.6 sec (P <0.001), 20 cmH2O: 56 sec (P <0.001), and 10 cmH2O with persistent irrigation: 72.8 sec (P <0.01 compared to 10 cmH2O without persistent irrigation). The maximum caliber of mice's tail artery was 50-60 µm. Hydrostatic pressure and irrigation are important factors contributing to hemostasis.

A Case of Primary Leptomeningeal Lymphoma Presenting with Hydrocephalus Characterized by Disproportionately Large Fourth Ventricle.

Primary leptomeningeal malignant lymphoma (PLML) is a rare variant of primary central nerve system malignant lymphoma (PCNSL) which is restricted to leptomeninges. The lesions of PLML can often be detected as abnormal enhancement on the surface of central nervous system or the ventricular wall on magnetic resonance imaging (MRIs). Cerebrospinal fluid (CSF) evaluation together with such MRI findings provides the definitive diagnosis of PLML. Here, we present a 45-year-old female case of PLML in which hydrocephalus with disproportionately large fourth ventricle was observed at presentation with gait instability. Head MRI revealed no abnormal enhancement and CSF cytology was negative, leaving the cause of hydrocephalus undetermined. Endoscopic third ventriculostomy (ETV) was effectively performed for hydrocephalus and her symptoms disappeared. Nearly 2 years later, she was brought to emergent room due to unconsciousness with the recurrence of hydrocephalus. MRI showed expanded fourth ventricle and abnormal enhancement on the ventricular wall. The endoscopic surgery for improving CSF flow was successful and inflammatory change was endoscopically observed on the ventricular wall involving aqueduct. Pathological diagnosis of the specimen from the ventricular wall proved B-cell lymphoma. Because neither brain parenchymal masses nor systemic tumors were identified, she was diagnosed with PLML and treated by high-dose methotrexate. She was in a stable state 2 years after the diagnosis of PLML. We report and discuss the characteristics of this case.

Fully Endoscopic Transcylinder Trans-Magendie Foraminal Approach for Fourth Ventricular Cavernoma: A Technical Case Report.

BACKGROUND: Neuroendoscopy offers wide and close surgical views with fine illumination, even in deep surgical sites. Furthermore, transcylinder surgery has the advantage that a tubular retractor can protect critical neurovascular structures in the surgical corridor. These advantages of neuroendoscopy and transcylinder surgery can contribute to safer and less invasive surgical approaches for deep-seated fourth ventricular lesions, for which various critical neurovascular structures exist along the surgical route. CASE DESCRIPTION: A 54-year-old man with a fourth ventricular cavernoma underwent tumor resection via the endoscopic transcylinder trans-Magendie foraminal approach. A 6.8-mm transparent sheath (cylinder) was introduced into the fourth ventricle via the foramen of Magendie without incisions in the inferior medullary velum or the tela choroidea, resulting in the minimal retraction of and trauma to critical neurovascular structures in the surgical corridor. Under the view of a 2.7-mm rigid neuroendoscope, the lesion was completely removed with preservation of a venous anomaly on the ventral side of the aqueduct of Sylvius. Neuroendoscopy could offer a fine surgical view even under continuous irrigation with artificial cerebrospinal fluid; it prevented collapse of the fourth ventricle and facilitated anatomic understanding by the surgeons. The postoperative course was uneventful. CONCLUSIONS: Our novel approach can be an effective surgical option for fourth ventricular lesions with minimal cerebellar retraction and injury.

Peel-off resection of the pituitary gland for functional pituitary adenomas: pathological significance and impact on pituitary function.

PURPOSE: Functional pituitary adenomas (FPAs) lacking a well-defined pseudocapsule can invade the adjacent pituitary gland. In such situations, peel-off resection of the adjacent pituitary gland after selective adenomectomy might lead to complete tumor removal, resulting in optimal endocrinological outcomes. Here, we present the significance of peel-off resection of the pituitary gland in patients with FPA in whom complete extracapsular tumor removal cannot be achieved. METHODS: We performed a retrospective review of 21 patients with FPA who underwent transsphenoidal surgery (TSS). After selective adenomectomy, peel-off resection of the adjacent pituitary gland was performed in 13 patients because complete extracapsular resection could not be achieved, while peel-off resection was not performed in the remaining 8 patients because complete extracapsular resection was accomplished. The clinical outcomes of these groups were compared. The pituitary tissues obtained by peel-off resection were pathologically examined for tumor cells. RESULTS: Early postoperative biochemical remission was achieved in 20 patients (95.2%). Anterior pituitary functions were not aggravated postoperatively in any patient: however, transient diabetes insipidus (DI) occurred in 2 patients. There were no statistically significant differences in the clinical outcomes of the two groups. A pseudocapsule was pathologically detected in the adjacent anterior pituitary even in patients in whom no pseudocapsule was intraoperatively detected. Tumor cells were pathologically detected in 7 (58.3%) of 12 pituitary tissues examined. CONCLUSIONS: Peel-off resection of the pituitary gland, which can remove a small tumor cell remnant in the adjacent pituitary, might maximize the effectiveness of TSS with minimal impact on postoperative pituitary function.

Removal of the Medial Wall of the Cavernous Sinus for Functional Pituitary Adenomas: A Technical Report and Pathologic Significance.

BACKGROUND: Removal of the medial wall of the cavernous sinus (MW) is challenging for neurosurgeons. We describe a practical method of endoscopic MW removal via endonasal transsphenoidal approach to minimalize intraoperative blood loss and postoperative morbidities. We also present the pathologic significance of this technique for functional pituitary adenomas (FPAs). METHODS: We performed MW removal in patients with FPA with no well-defined pseudocapsule and a tumor in direct contact with the MW. The MW was judged to have tumor invasion based on the intraoperative appearance, and it was removed regardless of the appearance of MW involvement. Intraoperative findings and postoperative clinical, endocrinologic, and pathologic outcomes were retrospectively reviewed. RESULTS: Fourteen patients underwent MW removal for FPA, including 12 patients with acromegaly and 2 with Cushing disease. Mean intraoperative blood loss was 170 mL (range, 32-400 mL), and none of the patients required blood transfusion. Among the 7 patients without intraoperative apparent MW involvement, 4 (57.1%) had pathologically confirmed tumor invasion into the MW (occult invasion). Biochemical remission by surgery alone was achieved in 13 patients (92.9%). Transient oculomotor palsy occurred in 1 patient (7.1%). CONCLUSIONS: Occult tumor invasion into the MW was often detected in patients with FPA without a well-defined pseudocapsule but in direct contact with the MW. Our technique can enhance the effectiveness of surgery with minimal postoperative morbidities.

Effectiveness of Goreisan in Preventing Recurrence of Chronic Subdural Hematoma.

BACKGROUND: Burr-hole irrigation surgery is now recognized as a widespread simple technique for the treatment of chronic subdural hematoma (CSDH). However, recurrence of CSDH is sometimes experienced after initial surgery. Recently, it has been reported that goreisan is effective in preventing CSDH recurrence. MATERIALS AND METHODS: Methods: We studied patients with CSDH who received burr-hole irrigation at our hospital between January 2011 and December 2014. We divided these patients into three groups. The first group was given goreisan during the early phase after burr-hole irrigation. The second group was given goreisan when there was a visual tendency of recurrence, as observed in the course of computed tomography imaging for outpatients. The third group was not given any drug. RESULTS: The recurrence rate was compared between each group. The recurrence rate was significantly lower in the early goreisan administration group (5% vs. 12%, P = 0.046). There was a decreased tendency of recurrence in the goreisan-administered group compared with the group that was not administered any drug, but this was not statistically different (6.1% vs. 12%, P = 0.082). The recurrence period in the goreisan-administered group was longer than that in the group that was not administered any drug (39.9 ± 12.1 vs. 27.45 ± 8.5, P = 0.017). CONCLUSIONS: Goreisan is effective in preventing recurrence of CSDH after burr-hole irrigation.

A Case of Acute Isolated Posterior Cerebral Artery Occlusion Successfully Treated with Endovascular Clot Aspiration.

Posterior cerebral artery (PCA) strokes produce various symptoms. Therefore, the diagnosis is often delayed and patients arrive late for thrombolytic therapy. We report a case of acute isolated PCA occlusion that was successfully treated with endovascular clot aspiration. A 63-year-old man presented with right complete homonymous hemianopia. Diffusion-weighted image (DWI) showed a high-intensity area (HIA) in the occipital lobe, and magnetic resonance angiography (MRA) showed PCA occlusion. Emergency endovascular clot aspiration was performed immediately after the diagnosis. Blood flow in PCA completely recovered 210 min after symptom onset. DWI after surgery showed partial disappearance of HIA, and the patient recovered from the symptom of right complete homonymous hemianopia. Endovascular recanalization is useful for acute PCA occlusion. This is the first reported case of acute isolated PCA occlusion successfully treated with endovascular clot aspiration. Prompt reperfusion results in a good clinical course in patients with PCA stroke. In this case, endovascular clot aspiration resulted in prompt recanalization in a patient with acute isolated PCA occlusion.

[A Novel, Less Invasive Protection Method for Carotid Artery Stenting].

Purpose: We present a novel, less invasive protection method for carotid artery stenting. Case presentation: A 67-year-old man presented with symptomatic severe left carotid artery stenosis. A transfemoral approach was dangerous because of an abdominal aortic aneurysm. A 6Fr Axcelguide Simmonds catheter was inserted into the right brachial artery, and advanced into the left common carotid artery. Next, a 6Fr Optimo 100-cm catheter was coaxially navigated into the left common carotid artery. A PercuSurge GuardWire 300-cm was coaxially navigated into the left external carotid artery. Under flow reversal with the 2 balloons, another PercuSurge GuardWire 300-cm was navigated into the distal left internal carotid artery through the lesion. After both PercuSurge GuardWire balloons were inflated, the 6Fr Optimo was deflated and retrieved using a catheter exchange technique. Then, under distal double-balloon protection, routine stenting was performed. Conclusions: This technique is safer and less invasive than previous methods, especially in cases with difficult femoral access and vulnerable carotid plaque.

Patterns of Recurrence After Resection of Malignant Gliomas With BCNU Wafer Implants: Retrospective Review in a Single Institution.

BACKGROUND: Bis-chloroethylnitrosourea (BCNU) wafers have been demonstrated to be effective for prolonging survival for patients with malignant glioma and have been approved worldwide. BCNU wafers are implantable and have a unique feature of delivering chemotherapeutic drug at high concentration at tumor margin over time after resection. BCNU wafers presumably, by this mechanistic rationale, have a beneficial effect on local tumor control and thus could change the pattern of recurrence, which is most frequently local. However, no studies have demonstrated such phenomenon after BCNU wafer implants. METHODS: To investigate whether the surgeries with BCNU wafers alter the predominant tendency of local recurrence pattern, we retrospectively reviewed 8 malignant glioma patients treated with BCNU wafers (BCNU wafer group), together with 22 glioma patients who did not receive BCNU wafers (no-BCNU wafer group) for comparison. RESULTS: Out of 6 patients in BCNU wafer group who exhibited recurrence, 1 showed local, 2 showed diffuse, and 3 showed a distant recurrence pattern, which was away from resection cavity. On the other hand, out of 18 patients in the no-BCNU wafer group who exhibited recurrence, 10 showed a local pattern, 8 showed a diffuse pattern, and no cases showed distant pattern. Distant pattern was observed significantly more frequently in the BCNU wafer group than in the no-BCNU wafer group. CONCLUSIONS: These results suggest that BCNU wafers could have a beneficial effect on local tumor control and may provide BCNU wafers with a new profile that could be considered for establishing future chemotherapeutic strategy for glioma patients.

Preoperative embolization of meningiomas with low-concentration n-butyl cyanoacrylate.

The aim of this study was to determine the clinical safety and efficacy of preoperative embolization of meningiomas with low-concentration n-butyl cyanoacrylate (NBCA). Nineteen cases of hypervascular intracranial meningiomas were treated by preoperative embolization with 14% NBCA, using a wedged superselective catheterization of feeding arteries and reflux-hold-reinjection technique. Clinical data of the patients and radiological and intra-surgical findings were reviewed. All tumors were successfully devascularized without any neurological complications. Marked reduction of tumor staining with extensive NBCA penetration was achieved in 13 cases. Perioperative blood transfusion was only required in two cases. These results indicate that preoperative embolization of meningiomas with low-concentration NBCA is both safe and effective.

[A Case of Cavernous Sinus Dural Arteriovenous Fistula after Transverse-Sigmoid Sinus Dural Arteriovenous Fistula Treatment with Radical Transvenous Coil Embolization].

PURPOSE: We report a case of cavernous sinus dural arteriovenous fistula (dAVF) that developed after the treatment of a transverse-sigmoid sinus dAVF using transvenous embolization (TVE). CASE PRESENTATION: A 72-year-old woman presented with headache and left-sided tinnitus. Angiography demonstrated the presence of a left transverse-sigmoid sinus dAVF. After TVE, the patient's symptoms completely disappeared. Three years later, she complained of left-sided tinnitus and diplopia, and angiography revealed the presence of a left cavernous sinus dAVF. We performed transvenous coil embolization, and the dAVF disappeared. CONCLUSIONS: TVE has been widely recognized as an effective treatment for dAVF. However, dAVF may develop at a different location after TVE in a few cases. A long-term follow-up is therefore recommended.

A case of ruptured intrameatal aneurysm successfully treated with coil embolization.

Aneurysms within the internal acoustic canal are rare. We report the case of a 71-year-old female with subarachnoid hemorrhage resulting from a ruptured distal anterior inferior cerebellar artery which was not detected on initial radiological examination. A second rupture was detected by contrast-enhanced computed tomography and successfully treated by endovascular coil embolization. The patient recovered without neurological deficits. To the best of our knowledge, this is the first report of an intrameatal aneurysm treated by endovascular coil embolization. We suggest endovascular coil embolization as an alternative to open surgery, even in cases of deep intrameatal aneurysm.

[Case of an anterior communicating artery aneurysm with acute in-stent occlusion during coil embolization].

PURPOSE: We report a case of acute in-stent occlusion during a stent-assisted coil embolization of a communicating artery aneurysm. CASE PRESENTATION: A 58-year-old man presented with a regrowth of an anterior communicating artery aneurysm one year after the initial coil embolization. An acute in-stent occlusion occurred during coil filling through the stent strut. We performed a successful recanalization of the stent using antithrombotic agents. CONCLUSIONS: Acute in-stent occlusion is a possible complication of stent-assisted coil embolization of aneurysms, particularly in narrow parent arteries. Our patient was recovered using antithrombotic drugs and did not present any major ischemic symptoms.