Perioperative Antiplatelet Management in the Flow-Diverter Treatment for Unruptured Cerebral Aneurysms: A Single-Center, Retrospective Analysis.

BACKGROUND: Although periprocedural antiplatelet therapy for the treatment of unruptured intracranial aneurysms (UIAs) using flow-diverter stents (FDSs) is necessary to avoid thromboembolic complications, a definite antiplatelet therapy has not been established. We aimed to evaluate the safety and efficacy of periprocedural antiplatelet management in UIA treatment with FDS. METHODS: A single-center retrospective analysis of consecutive patients with UIAs treated with FDSs between September 2013 and January 2022 was conducted. Patients received dual antiplatelet therapy (DAPT) (aspirin and clopidogrel) for 14-day before and 3-6 months after FDS placement. Platelet aggregation was evaluated prior to treatment using light transmission aggregometry, which was classified into 3 grades; 1-3: promoted, 4-6: appropriate, and 7-9: non-responder, for adenosine diphosphate (ADP) and collagen. By this classification, the antiplatelet regimen was modified. Outcome included hemorrhagic and ischemic events. RESULTS: 193 patients with 200 UIAs underwent 213 FDSs placement. The median platelet aggregability grade before treatment was 5 for ADP and 4 for collagen. Antiplatelet therapy modification was performed in 62 patients (32.1%). The median postoperative DAPT duration was 94 days. Antiplatelet medicine-related hemorrhagic events occurred in 4 patients (2.1%) and ischemic events occurred in 6 patients (3.1%). These patients had no morbido-mortality. CONCLUSIONS: Periprocedural antiplatelet management based on the value of platelet aggregability was relatively safe and effective for treating UIA with FDS.

3D phase-sensitive inversion recovery sequence for intracranial vertebrobasilar artery dissection.

BACKGROUND: T1-weighted 3D turbo spin echo (T1W-3D-TSE) sequences with variable refocusing flip angle are commonly used to diagnose intracranial vertebrobasilar artery dissection (iVAD). However, magnetic susceptibility artifacts of the cavernous sinus may cause loss of the basilar and vertebral arteries. This study investigated the effectiveness of a 3D phase-sensitive inversion recovery (3D-PSIR) sequence in reducing magnetic susceptibility artifacts in the cavernous sinus, and its imaging findings for iVAD. METHODS: Twelve volunteers and eleven patients with iVAD were included. Magnetic resonance imaging (MRI) was performed using a 3.0-T MRI system. 3D-PSIR and T1W-3D-TSE sequences were used. Vessel wall defects and contrast-to-noise ratio (CNR) were evaluated. The MRI findings were visually evaluated. RESULTS: In the 3D-PSIR images, one volunteer (8 %) had vessel wall defects, and five (42 %) had vessel wall defects (p = 0.046) in the T1W-3D-TSE images. CNR was higher in 3D-PSIR images for vessel wall-to-lumen, whereas it was higher in T1W-3D-TSE images for vessel wall-to-CSF (p < 0.001). Visual evaluation revealed similar MRI findings between the two sequences. CONCLUSIONS: The 3D-PSIR sequence may be able to improve the vessel wall defects and achieve MRI findings comparable to those of the T1W-3D-TSE sequence in iVAD. The 3D-PSIR sequence can be a useful tool for the imaging-based diagnosis of iVAD.

Distal Transradial Approach in Mechanical Thrombectomy: Technical Note.

Objective: We report a case of mechanical thrombectomy (MT) via the distal transradial approach (dTRA) and technical tips. Case Presentation: An 89-year-old woman was transferred to our hospital due to back pain after a fall and sudden-onset left hemiparesis. We performed MT because three-dimensional computed tomography angiography (3D-CTA) revealed right middle cerebral artery (MCA) occlusion. The access route was Type 3 aortic arch. The abdominal aorta and common iliac artery were tortuous and partially dissected, and she had a lumbar vertebra fracture. We selected dTRA in consideration of safety, ease of access, and less postoperative postural restriction. The first pass resulted in complete recanalization using an aspiration catheter and stent retriever. Her symptoms rapidly improved and she was discharged with a modified Rankin Scale score of 1. Conclusion: dTRA in MT may be a treatment option.

Ruptured Dissecting Aneurysm of the Carotid Artery 12 Years after Gamma Knife Therapy for Pituitary Adenoma.

Objective: We report a rare case of carotid artery dissection leading to fatal epistaxis 12 years after Gamma knife surgery. Case Presentation: A 65-year-old woman underwent Gamma knife surgery for remnant pituitary adenoma adjacent to the left cavernous sinus after transsphenoidal tumor removal. After 12 years, she developed repetitive critical hematemesis subsequent to cardiopulmonary arrest, and a dissecting aneurysm of the cavernous segment of the left internal carotid artery (ICA) was identified by cerebral angiography after resuscitation and massive blood transfusion. Effective hemostasis was confirmed by endovascular embolization to occlude the affected carotid artery. She was transferred to a rehabilitation facility 1 month after onset. Conclusion: The etiology of this pathology may have been a collapsed vasa vasorum or fibrosis of adventitia on the carotid wall adjacent to the irradiated site. We need to suspect this rare but serious pathology in patients with histories of irradiation of the cavernous region who develop massive hematemesis of unknown origin.

[A Case Report of Brain Metastasis from Anal Canal Carcinoma].

A 55-year-old female with adenocarcinoma of anal canal(stage IV with lung, bone, and lymph node metastasis)underwent total pelvic exenteration surgery and chemotherapy. Chemotherapy was continued after the surgery. One month later, she presented to the emergency room with gait disorder and cognitive dysfunction. CT and MRI demonstrated metastatic brain tumor in the right cerebellar hemisphere. Craniotomy and CyberKnife surgery were performed. Histological examination revealed adenocarcinoma with atypical cells forming a papillary arrangement. She died 35 weeks after the surgery. Brain metastasis from anal carcinoma is very rare, but recent advances in chemotherapy are achieving favorable results of long-term survival, and this is likely to increase in the future. Early detection, early treatment, and combined therapy may improve the long-term outcome for patients.

[A Case of Primary Intracranial Malignant Melanoma Mimicking a Traumatic Brain Contusion].

Primary intracranial malignant melanoma(PIMM)is a rare neoplasm of the central nervous system, accounting for 1% of cases of malignant melanomas and 0.1% of cases of brain tumors. Here, we report a case of PIMM that was initially considered to be a traumatic brain contusion. A 44-year-old man was transferred to a local hospital because of general tonic convulsion after falling while riding a bike. CT showed an irregular high-density area in the left temporal pole, which was diagnosed as a traumatic contusion. MRI performed 3 months after the initial episode revealed an enlarged temporal lesion with surrounding edema, suggestive of a neoplasm. The MRI showed the lesion as mixed signal intensity, suggesting both solid and cystic components. Subtotal resection was performed, except for the tumor adhering to the peripheral middle cerebral arteries(MCAs). The definitive diagnosis was made based on pathological findings and no evidence of extracranial lesions. Gamma knife surgery was performed for the remnant tumor adjacent to MCAs. The radiologically positive tumor chronologically regressed, and the patient remained progression-free for 18 months. Radiological findings of PIMM vary but typically include high density on CT and hyperintensity on T1-weighted MRI. Close observation enabled early diagnosis based on the suspicion of a neoplasm according to atypical radiological findings. PIMM has a poor prognosis with an overall survival of 12.0 months without confirmative treatment. Gamma knife surgery might achieve suppression of this highly progressive tumor.

[Hemifacial Spasm Caused by Vertebral Artery Fusiform Aneurysm and the Anterior Inferior Cerebellar Artery].

We report a case of hemifacial spasm in which the root exit zone(REZ)of the facial nerve was compressed by both the vertebral artery(VA)aneurysm and the anterior interior cerebellar artery(AICA). A 60-year-old female had suffered left hemifacial spasm for 2 years. Three-dimensional rotational angiography with selective arterial infusion of contrast medium(3DRA-IA)revealed that a distal part of the left AICA looping at the cisternal region was contacting the dome of the left VA aneurysm, although other imaging modalities did not show the exact course of the ipsilateral AICA. Constructive interference steady state magnetic resonance imaging revealed that both the left VA aneurysm and the left AICA had compressed the REZ of the left facial nerve. She underwent aneurysm clipping and decompression of the REZ by transposition of both the clipped aneurysm and the AICA using TachoSil®. Her hemifacial spasm disappeared immediately after surgery without complication. Some fine arteries might compress the REZ in patients with hemifacial spasm associated with VA aneurysms. 3DRA-IA was more effective for accurate evaluation than other imaging modalities. Transposition of vascular structures using TachoSil® is safe and effective for microvascular decompression surgery in such complicated cases.

[Surgical Treatment for Traumatic Acute Subdural Hemorrhage in the Posterior Cranial Fossa:Three Cases Reports and Review of the Literature].

Acute subdural hemorrhage(ASDH)in the posterior cranial fossa is rare. Extremely unfavorable outcomes are reported among cases accompanied by supratentorial hematoma, brainstem contusion, or intracerebellar contusion. We report three cases surgically evacuated several times for traumatic ASDH in the posterior cranial fossa simultaneously accompanied by supratentorial hematomas. In our three presented cases, the mean age was 72.3 years, and all patients were male. The mechanisms of injury included traffic accidents in two cases and fall in one. The median Glasgow Coma Scale score on admission was 6. On admission, the patients had traumatic ASDH in the posterior cranial fossa accompanied by supratentorial hematoma, so they first underwent external decompression or ICP sensor insertion for the supratentorial lesions. However, after their first surgery, all patients developed upward herniation, and subsequently underwent suboccipital craniotomy and evacuation of hematomas. Glasgow Outcome Scales were death in one case, persistent vegetable state in one case, and severe disability in one case. The patients with ASDH in the posterior cranial fossa accompanied by supratentorial hematoma should immediately undergo suboccipital craniotomy and supratentorial decompression simultaneously when the hematomas compress the brainstem and upward herniation develops.

[Surgical Treatment of a Giant Olfactory Groove Schwannoma:A Case Report].

Schwannomas originating from the olfactory nerve are extremely rare because the olfactory nerve does not normally contain Schwann cells. We describe a case of a giant schwannoma of the olfactory groove. A 73-year-old woman presented with anosmia persisting for 10 months. Head computed tomography(CT)for head trauma at another hospital demonstrated a tumor lesion located in the left frontal lobe and paranasal sinus. She had never suffered epilepsy, and past medical history and family history identified no indicators. Neurological examination revealed anosmia and dementia. Head CT demonstrated a tumor lesion with bone erosion, causing a defect of about 5cm in the frontal base. Head magnetic resonance(MR)imaging with contrast medium indicated a lesion that was 6cm in diameter, with heterogeneous enhancement and severe perifocal edema in the left frontal base, extending into the paranasal cavity. The tumor was resected through a left extradural subfrontal approach with bicoronal frontal craniotomy. The endoscopic approach was also performed simultaneously to remove the tumor in the paranasal sinus. The cystic tumor was soft and easy to bleed. Intraoperatively the right olfactory nerve was confirmed, but the left olfactory nerve could not be identified because of replacement by the tumor, suggesting that the tumor had originated from the left olfactory nerve. The defect of the dura was repaired with femoral fascia, the pedunculated periosteal flap was laid over the frontal base, and the bone defect was repaired with the inner plate of the frontal calvaria. Postoperative head MR imaging with contrast medium revealed no residual lesion. The patient was discharged 25 days after surgery, without new neurological deficits. Histological examination identified mixed Antoni type A and Antoni type B schwannoma on hematoxylin and eosin staining and S-100 protein on immunostaining.

Surgical Microanatomy of the Posterior Condylar Emissary Vein and its Anatomical Variations for the Transcondylar Fossa Approach.

BACKGROUND: It is essential to identify and be aware of the anatomy of the posterior condylar emissary vein (PCEV) for achieving an adequate operative field for the transcondylar fossa approach (TCFA). OBJECTIVE: To describe the variations in the drainage patterns of PCEVs and the technical issues encountered in such cases. METHODS: This was a retrospective analysis of the anatomy of PCEVs in 104 sides in 52 cases treated by the TCFA. Preoperative findings of multidetector-row computed tomography (CT) and CT venography (CTV) were compared with the intraoperative findings. The drainage patterns were classified as 5 types: the sigmoid sinus (SS), jugular bulb (JB), occipital sinus (OS), anterior condylar emissary vein (ACEV), and marginal sinus (MS). RESULTS: The SS, JB, ACEV, and OS types were observed in 33 (31.7%), 42 (40.3%), 8 (7.7%), and 1 (1.0%) side(s), respectively. One side (1.0%) each had combined drainage from MS and JB, and ACEV and JB, respectively. In 17 sides (16.3%), the PCEVs and posterior condylar canals could not be identified on CT and CTV. CONCLUSIONS: Preoperative CT and CTV findings correlated well with the intraoperative findings. To make a sufficient operative field for TCFA, PCEVs should be appropriately dealt with based on the preoperative knowledge of their running course, pattern, and origin.

Impacts of pressure bonding fixation on a bone flap depression and resorption in patients with craniotomy.

Fixation of bone flaps after craniotomy is a routine part of every neurosurgical procedure. Common problems encountered are bone flap depression and resorption. Authors performed the pressure-bonding bone flap fixation (PBFF) using absorbable craniofix (AC) and hydroxyapatite wedge (HW). The aim of the present study is to evaluate the efficacy of PBFF to prevent a bone flap depression and resorption in patients treated with craniotomy. Four-hundred fifty-four patients underwent craniotomies. Authors collected the following data: age, sex, type of craniotomy, what kind of surgery, whether bypass surgery was performed, whether surgery was the initial, whether AC and the HW were used, bone flap depression and resorption at 6-month after the craniotomy. PBFF was defined as a bone flap fixation using both AC and HW to impress a bone flap to forehead. The mean age was 62±13years and 404 (89%) patients were women. PBFF was performed in 71 patients (16%), either AC or HW was used in 141 (31%), only AC was used in 116 (25%), and only HW was used in 25 (5.5%). At 6-month after the surgery, a bone flap depression was seen in 38 patients (8.4%), and a bone flap resorption was seen in 66 (15%). Multivariate analysis showed that only a PBBF showed a negative correlation with bone flap depression (p=0.044) and resorption (p=0.011). The results of the present study showed that PBFF reduced a bone flap depression and resorption and provided excellent postoperative cosmetic results.

A Contralateral Transcondylar Fossa Approach with Bilateral V3 Segment Exposure for Repairing Complex Vertebral Artery Aneurysms.

BACKGROUND AND IMPORTANCE: Microsurgical treatment for vertebral artery aneurysms can be approached through the lateral aspect of the brainstem and cerebellum. A contralateral approach may be selected in complex aneurysms with tortuous running and the intracranial vertebral artery distal to the aneurysm located in the contralateral cerebellopontine angle. When repairing the aneurysm, exposing the V3 segment before craniotomy is advantageous. We describe the detailed surgical procedures of the contralateral transcondylar fossa approach with bilateral V3 segment exposure for the repair of a complex vertebral artery aneurysm. CLINICAL PRESENTATION: A 48-year-old woman presented with a 23-mm unruptured thrombosed fusiform aneurysm in the right vertebral artery. The aneurysm and the V4 segment distal to it deviated to the left, and the aneurysm was compressing the left anterior aspect of the medulla oblongata. We treated the patient with trapping and thrombectomy, using a contralateral transcondylar fossa approach with bilateral V3 exposure. During the procedure, proximal vascular control was achieved by occluding the contralateral V3 segment and distal control was achieved by occluding the V4 segment. The aneurysm was successfully trapped and decompressed. The patient's postoperative course was good and she was discharged with a modified Rankin Scale score of 0. CONCLUSIONS: The contralateral transcondylar fossa approach with bilateral V3 exposure is feasible for the repair of complex vertebral artery aneurysms showing a deviated and difficult to access V4 segment proximal to the aneurysm. Bilateral V3 exposure may also facilitate aneurysm bypass procedures such as those using a V3-V4 anastomosis.

Radical resection of a craniopharyngioma via the extradural anterior temporal approach with zygomatic arch osteotomy.

BACKGROUND: Though the extradural anterior temporal approach (EDATA) with zygomatic osteotomy is useful, there are only few reports of this approach being used for craniopharyngioma resection. Herein, we report our surgical case series and the technical importance of EDATA for the radical removal of a craniopharyngioma. METHODS: We report 7 cases of craniopharyngiomas treated surgically between April 1999 and October 2015. The surgical approaches, clinical presentation, pre and postoperative radiographic examination results, surgical outcomes, and morbidity were analyzed. RESULTS: The mean follow-up period was 89.1 months. The surgical approach was EDATA with zygomatic osteotomy in 4, combined interhemispheric translamina terminalis approach (IHTLA) and trans-sylvian anterior temporal approach (ATA) in 2, and IHTLA in 1 patient. Complete tumor resection was achieved in all cases, without any recurrence during the follow-up period. Transient morbidities were oculomotor nerve palsy in 2, and meningitis and hydrocephalus in 1 patient. There was 1 case of permanent morbidity due to hydrocephalus that needed a ventriculoperitoneal shunt, and 1 case of blindness on the operative side. Visual acuity and visual field improved in 4 cases, showed no change in 2 cases, and deteriorated in 1 case. Though the pituitary stalk was preserved in 2 cases, all 7 cases needed total hormone replacement therapy. CONCLUSION: EDATA with zygomatic osteotomy ensures sufficient mobility of the internal carotid artery, and provides a good lateral and look up operative view. Hence, it can be used effectively for radical resection of craniopharyngiomas through the opticocarotid space and retrocarotid space.

Surgical Strategy for Complex Anterior Cerebral Artery Aneurysms: Retrospective Case Series and Literature Review.

OBJECTIVE: Giant, or complex, aneurysms of the anterior cerebral artery (ACA) are rare, but their surgical treatment is important. The authors describe their experiences with bypasses for complex ACA aneurysms and discuss the new classification of ACA bypasses, the concept of using bypasses for insurance during the approach to the aneurysm, and simplifying the surgical algorithms for these complex ACA aneurysms. METHODS: Over a 19-year period, 7 cases of complex ACA aneurysm were treated with bypasses and reviewed retrospectively. The bypasses were classified into 4 groups according to donor blood flow: internal carotid artery-ACA, external carotid artery-ACA, communicating bypass, and reconstruction bypass of the ipsilateral postcommunicating ACA. RESULTS: The cases included 1 precommunicating aneurysm, 3 communicating aneurysms, 2 postcommunicating aneurysms, and 1 double aneurysm (communicating and postcommunicating). The types of bypass included 1 internal carotid artery-ACA, 6 communicating bypasses, 3 external carotid artery-ACAs, and 2 reconstruction bypass of the postcommunicating ACA. Postoperative modified Rankin Scale scores were 0 (6 cases) and 3 (1 case of a communicating aneurysm with complicated memory disturbance because of infarction). One case revealed asymptomatic infarction. CONCLUSIONS: Surgical treatment of complex ACA aneurysms requires knowledge of a variety of bypass techniques. Although the type of bypass should be selected according to patient-specific anatomy and the neurosurgeon's preference, the new classification of bypass-specified ACA aneurysms may alter the way surgeons think about ACA bypasses, and in combination with the concept of the protective bypass, can be used to establish a comprehensive algorithm for each type of complex ACA aneurysm.