Pseudoaneurysm formation or dural arteriovenous fistula formation at the middle meningeal artery following revascularization surgery in Moyamoya disease

Moyamoya disease (MMD) is a rare progressive steno-occlusive cerebrovascular disorder. Currently, revascularization surgery is used as optimal treatment to overcome MMD. However, revascularization for MMD has reported several complications. Also, iatrogenic complications such as pseudoaneurysms formation or dural arteriovenous fistulas (dAVFs) formation—has been identified in rare cases after the surgical intervention for revascularizations.We describe two cases. In first case, the patency of the anastomosis site was good and saccular type pseudoaneurysm formation was found at parietal branch of posterior middle meningeal artery (MMA) in transfemoral cerebral angiography (TFCA) performed on the twelfth day after surgery. We decided to treat pseudoaneurysm by endovascular embolization the next day, but the patient was shown unconsciousness and anisocoria during sleep at that day. Computed tomography showed massive subdural hemorrhage at the ipsilateral side, thus we performed decompressive craniectomy and hematoma evacuation.In second case, the patency of the anastomosis site was good and dAVF formation at right MMA was found in TFCA performed on the sixth day after surgery. We performed endovascular obliteration of the arteriovenous fistula under local anesthesia.Pseudoaneurysm formation or dAVF formation after revascularization surgery is an exceptional case. If patients have such complications, practioner should carefully screen the patients by implementing digital subtraction angiogram to identify anatomic features; as well as consider immediate treatment in any way, including embolization or other surgery

Middle meningeal artery embolization for chronic subdural hematoma in elderly patients at high risk of surgical treatment

Objective@#The purpose of this study was to evaluate the effectiveness of middle meningeal artery embolization (MMAE) in elderly high-risk patients with symptomatic chronic subdural hematoma (CSDH) in terms of reduction in hematoma volume and recurrence rate. @*Methods@#We retrospectively reviewed data prospectively collected from nine patients who underwent 13 MMAE for CSDH between June 2017 and May 2022. The volume of the subdural hematoma was measured using a computer-aided volumetric analysis program. Hematoma volume changes during the follow-up period were analyzed and clinical outcomes were evaluated. @*Results@#The mean follow-up period was 160 days (range, 46−311 days). All procedures were technically successful and there were no procedure-related complications. Of the 13 MMAE, 84% (11 out of 13 hemispheres) showed mean 88% of reduction on follow-up volumetric study with eight cases of complete resolution. There was one refractory case with MMAE which had been performed multiple burr-hole trephinations, for which treatment was completed by craniotomy and meticulous resection of multiple pseudomembranes. There was no recurrent case during the follow-up period, except for refractory case. @*Conclusions@#MMAE for CSDH in selected high-risk elderly patients and relapsed patients might be effective. Despite the small cohort, our findings showed a high rate of complete resolution with no complications. Further prospective randomized trials are warranted to evaluate its usefulness as a primary treatment option for CSDH.

Revisiting the Role of Surgical Resection for Brain Metastasis

Brain metastasis (BM) is the most common type of brain tumor in adults. The contemporary management of BM remains challenging. Advancements in systemic cancer treatment have increased the survival of patients with cancer. Although the treatment of BM is still complicated, advances in radiotherapy, including stereotactic radiosurgery and chemotherapy, have improved treatment outcomes. Surgical resection is the traditional treatment for BM and its role in the surgical resection of BM has been well established. However, refinement of the surgical resection technique and strategy for BM is needed.Herein, we discuss the evolving role of surgery in patients with BM and the future of BM treatment.

Survival Outcomes and Predictors for Recurrence of Surgically Treated Brain Metastasis From Non-Small Cell Lung Cancer

Background@#There are numerous factors to consider in deciding whether to undergo surgical treatment for brain metastasis from lung cancer. Herein, we aimed to analyze the survival outcome and predictors of recurrence of surgically treated brain metastasis from non-small cell lung cancer (NSCLC). @*Methods@#A total of 197 patients with brain metastasis from NSCLC who underwent microsurgery were included in this study. @*Results@#A total of 114 (57.9%) male and 83 (42.1%) female patients with a median age of 59 years (range, 27–79) was included in this study. The median follow-up period was 22.7 (range, 1–126) months. The 1-year and 2-year overall survival (OS) rates of patients with brain metastasis secondary to NSCLC were 59% and 43%, respectively. The 6-month and 1-year progression-free survival (PFS) rates of local recurrence were 80% and 73%, respectively, whereas those of distant recurrence were 84% and 63%, respectively. En-bloc resection of tumor resulted in better PFS for local recurrence (1-year PFS: 79% vs. 62%, p=0.02). Ventricular opening and direct contact between the tumor and the subarachnoid space were not associated with distal recurrence and leptomeningeal seeding. The difference in PFS of local recurrence according to adjuvant resection bed irradiation was not significant. Moreover, postoperative whole-brain irradiation did not show a significant difference in PFS of distant recurrence. In multivariate analysis, only En-bloc resection was a favorable prognostic factor for local recurrence. Contrastingly, multiple metastasis was a poor prognostic factor for distant recurrence. @*Conclusion@#En-bloc resection may reduce local recurrence after surgical resection. Ventricular opening and contact between the tumor and subarachnoid space did not show a statistically significant result for distant recurrence and leptomeningeal seeding. Multiple metastasis was only meaningful factor for distant recurrence.

Extraventricular Neurocytoma: Clinical Investigation of Heterogenous Prognosis

Background@#Extraventricular neurocytoma (EVN) is an extremely rare neuronal neoplasm that arises outside the ventricle. The clinical implication of the heterogenous prognosis of this rare tumor has not yet been clarified. Herein, we analyzed our institutional series of EVN. @*Methods@#A total of eight consecutive cases were enrolled and investigated. The prognosis of EVN was analyzed and compared to that of central neurocytoma (CN). @*Results@#There were two male and six female patients, and the median age was 36.5 years. The median tumor size was 38 mm, and the most common location of the tumor was the frontal lobe (3, 37.5%), followed by the parietal and temporal lobes. In brain imaging, four (50%) tumors showed peritumoral edema and three (37.5%) tumors showed calcification. All patients underwent gross total resection, and two (25%) underwent adjuvant radiotherapy. The 5-year overall survival (OS) was 55.6%, and the 2-year progression-free survival (PFS) was 42.9%. The OS and PFS of EVN were poor compared to those of CN. Although EVN is a single disease entity, individual patients showed varying prognosis. One patient showed no recurrence during the 7-year follow-up period; however, another patient had a recurrence 4 months after surgery and died 2 years later. @*Conclusion@#EVN may be a heterogenous disease entity. Additional cases with long-term followup are needed to develop optimal management protocols.

A Rare Case of Metastatic Brain Tumor From Classic Biphasic Pulmonary Blastoma Presented as Intracerebral Hemorrhage

Pulmonary blastoma is a rare type of primary lung cancer that accounts for only 0.25%-0.5% of all lung malignancies. Pulmonary blastoma consists of three subgroups: classic biphasic pulmonary blastoma (CBPB), pleuropulmonary blastoma, and well-differentiated fetal adenocarcinoma. Due to the rarity of the tumor, metastatic brain tumor from CBPB is extremely rare, and only 13 cases, including our case, have been reported. A 60-year-old woman who underwent left upper lobectomy of the lung because of pathologically diagnosed as CBPB 5 months ago, suddenly lost consciousness and presented with stupor mental status. The emergent CT scan showed a large, 51 mL, intracerebral hemorrhage on left parieto-occipital lobe with midline shifting. The patient underwent emergent craniotomy, and a hypervascular tumor was identified during the operation. Histopathologic examination reported metastatic pulmonary blastoma, CBPB. The patient has been in a vegetative state, but there has been no evidence of recurrence over a 6-month follow-up period. We report a rare case of brain metastasis from CBPB presenting with altered mentality due to massive tumor bleeding. This is the only reported case of brain metastasis from CBPB presenting with acute intracerebral hemorrhage.

Microsurgical treatment of lateral cavernous sinus wall dural arteriovenous fistula with large venous aneurysm: A case report

We report a case of lateral cavernous sinus wall dural arteriovenous fistula (DAVF) accompanied large venous aneurysm which is presented intracerebral hemorrhage (ICH). A 58-year-old male patient came to emergency department for acute onset of headache and dysarthria. In brain computed tomography scan, large left temporal lobe ICH was noted. In transfemoral cerebral angiography, multiple arteries from external carotid artery and left internal carotid artery (ICA) fed arteriovenous shunt. This shunt was drained through cavernous sinus with enlarged multiple cortical veins. One large venous aneurysm was estimated as bleeding focus for ICH. Considering ICH and high flow shunt, we planned urgent treatment to reduce flow of arteriovenous shunt. However, transvenous embolization was failed due to tortuous venous anatomy. Therefore, we planned craniotomy and microsurgical treatment. There was engorged small vessel in lateral wall of cavernous sinus and vascular trunk which is fistulous connection was noted. Fistula connection was obliterated and disconnected after coagulation. In postoperative image, fistula was completely disappeared and there was no cortical venous reflux, also large venous aneurysm was disappeared. Patient recovered very well without new neurological deficits. We reported successfully treated lateral cavernous sinus wall DAVF by combined endovascular and transcranial-microsurgical treatment.

Microsurgical treatment of lateral cavernous sinus wall dural arteriovenous fistula with large venous aneurysm: A case report

We report a case of lateral cavernous sinus wall dural arteriovenous fistula (DAVF) accompanied large venous aneurysm which is presented intracerebral hemorrhage (ICH). A 58-year-old male patient came to emergency department for acute onset of headache and dysarthria. In brain computed tomography scan, large left temporal lobe ICH was noted. In transfemoral cerebral angiography, multiple arteries from external carotid artery and left internal carotid artery (ICA) fed arteriovenous shunt. This shunt was drained through cavernous sinus with enlarged multiple cortical veins. One large venous aneurysm was estimated as bleeding focus for ICH. Considering ICH and high flow shunt, we planned urgent treatment to reduce flow of arteriovenous shunt. However, transvenous embolization was failed due to tortuous venous anatomy. Therefore, we planned craniotomy and microsurgical treatment. There was engorged small vessel in lateral wall of cavernous sinus and vascular trunk which is fistulous connection was noted. Fistula connection was obliterated and disconnected after coagulation. In postoperative image, fistula was completely disappeared and there was no cortical venous reflux, also large venous aneurysm was disappeared. Patient recovered very well without new neurological deficits. We reported successfully treated lateral cavernous sinus wall DAVF by combined endovascular and transcranial-microsurgical treatment.

Clinical Outcomes of Large (>10 mm) Unruptured Posterior Circulation Aneurysms and Their Predictors

Objective@#: The treatment of large aneurysms of the posterior circulation is complicated and remains challenging. We here analyzed our institutional clinical outcomes of large unruptured aneurysms of the posterior circulation. @*Methods@#: This study included 56 patients who presented with a large (>10 mm) unruptured aneurysm of the posterior circulation between 2002 and 2018. @*Results@#: There were 18 (32.1%) male and 38 (67.9%) female patients, with a mean age of 53.4 years. The most common location was the vertebral artery, followed by the basilar tip and posterior cerebral artery. The median follow-up duration was 29 months. Eighteen patients (32.1%) were treated by transcranial surgery and 38 (67.9%) were treated by endovascular treatment (EVT). Posttreatment complications occurred in 16 patients (28.6%), with there being no significant difference between the transcranial surgery and EVT groups. Complete obliteration was achieved in 30 patients (53.6%), with there being no statistically significant difference between the transcranial surgery and EVT groups. Recurrence occurred in 17 patients (30.4%), and the rate of recurrence was higher in the EVT group than in the transcranial surgery group (39.5% vs. 11.1%, p=0.03). Forty-four (84%) of 56 patients showed a favorable functional outcome. In saccular aneurysm, EVT was negative predictor of worsening of functional status. @*Conclusion@#: Treatment of these aneurysms harbors an inherent high risk of morbidity. No superiority was found between transcranial surgery and EVT in terms of complications and complete obliteration, but transcranial surgery showed a higher treatment durability than EVT.

Role of microsurgery for treatment of posterior circulation aneurysms in the endovascular era

Objective@#Several studies have reported that the outcomes of endovascular treatment were superior to those of microsurgical treatment for posterior circulation aneurysms. Thus, this study compared outcomes of endovascular and microsurgical treatment for posterior circulation aneurysms and assess the usefulness of microsurgery in these patients. @*Methods@#Outcomes were retrospectively evaluated after endovascular and microsurgical treatment of 621 posterior circulation aneurysms. The 621 aneurysms included 187 treated by surgical clipping and 434 treated by endovascular coiling. @*Results@#In patients with unruptured aneurysms the rates of residual lesions and retreatment were significantly lower in those who underwent microsurgical than endovascular treatment. However immediate postoperative and 6 month follow-up Glasgow outcome scale (GOS) scores did not differ significantly in the two groups. In patients with ruptured aneurysms, the rates of residual lesions and retreatment were significantly lower in the microsurgery than in the endovascular treatment group. Even so immediate postoperative and 6 month follow-up GOS scores did not differ significantly in the two groups. @*Conclusions@#Endovascular treatment has increasingly become an alternative modality for microsurgery in posterior circulation aneurysm, whereas the indication for microsurgery is greatly reduced. However, the absolute number of microsurgery is maintained showing that it is a still valuable technique, as advances in endovascular or stent-assisted coiling have not solved many of the challenges inherent in the management of complex aneurysms. Hence, the advantages and limitations of both modalities must be carefully concerned in posterior circulation aneurysm to obtain favorable outcome.

Thyroid-Stimulating Hormone-Secreting Pituitary Adenomas : Single Institutional Experience of 14 Consecutive Cases

Objective@#: Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (PA) is an extremely rare functioning form of PA that accounts for 0.7–2% of all such cases. The previously reported outcomes of the surgical removal of TSH-PA are poor. Owing to its extremely low incidence, most available reports on TSH-PA are case reports or small case series. Thus, we investigated the clinical and endocrinological outcomes of surgically treated TSH-PA through our institutional series. @*Methods@#: We retrospectively reviewed 14 consecutive cases of surgically treated TSH-PA, focusing on the clinical, radiological, surgical, and endocrinological data. @*Results@#: There were seven male (50%) and seven female (50%) patients. The mean age was 42.5 years (range, 19–63). The mean tumor size was 16.6 mm (range, 4–30). Optic chiasm compression was noted in six patients (42.9%), and no patient showed cavernous sinus invasion. Thirteen of 14 patients (92.8%) underwent transnasal transsphenoidal approach (TSA), and one patient underwent TSA followed by transcranial approach for residual tumor removal. Thirteen of 14 patients (92.8%) showed endocrinological remission; all patients who experienced remission showed subnormal levels of TSH (<0.4 μU/mL) on postoperative day 2. Recurrence occurred in two patients (14.2%). One patient underwent subsequent revision transnasal TSA for recurrent tumor removal, and the other patient underwent gamma knife radiosurgery for recurrence. @*Conclusion@#: Surgical treatment showed excellent surgical outcomes. The TSH level in the immediate postoperative period may be a predictor for endocrinological remission.

Radiosurgery for Cerebral Arteriovenous Malformation (AVM) : Current Treatment Strategy and Radiosurgical Technique for Large Cerebral AVM

Arteriovenous malformations (AVMs) are congenital anomalies of the cerebrovascular system. AVM harbors 2.2% annual hemorrhage risk in unruptured cases and 4.5% annual hemorrhage risk of previously ruptured cases. Stereotactic radiosurgery (SRS) have been shown excellent treatment outcomes for patients with small- to moderated sized AVM which can be achieved in 80–90% complete obliteration rate with a 2–3 years latency period. The most important factors are associated with obliteration after SRS is the radiation dose to the AVM. In our institutional clinical practice, now 22 Gy (50% isodose line) dose of radiation has been used for treatment of cerebral AVM in single-session radiosurgery. However, dose-volume relationship can be unfavorable for large AVMs when treated in a single-session radiosurgery, resulting high complication rates for effective dose. Thus, various strategies should be considered to treat large AVM. The role of pre-SRS embolization is permanent volume reduction of the nidus and treat high-risk lesion such as AVM-related aneurysm and high-flow arteriovenous shunt. Various staging technique of radiosurgery including volume-staged radiosurgery, hypofractionated radiotherapy and dose-staged radiosurgery are possible option for large AVM. The incidence of post-radiosurgery complication is varied, the incidence rate of radiological post-radiosurgical complication has been reported 30–40% and symptomatic complication rate was reported from 8.1% to 11.8%. In the future, novel therapy which incorporate endovascular treatment using liquid embolic material and new radiosurgical technique such as gene or cytokine-targeted radio-sensitization should be needed.