Factors and brain imaging features associated with cognition in oldest-old patients with Alzheimer-type dementia.

BACKGROUND: The underlying pathophysiology of cognitive dysfunction in oldest-old patients with Alzheimer-type dementia (AD) has not been clarified to date. We aimed to determine the factors and brain imaging features associated with cognition in oldest-old patients with AD. METHODS: We enrolled 456 consecutive outpatients with probable AD (145 men and 311 women, age range: 51-95 years). Demographic factors, such as education level, disease duration at initial visit, body mass index, comorbidities, frailty, and leisure activity, and brain imaging features, including severity of medial temporal lobe (MTL) atrophy, white matter lesions and infarcts, and frequency of posterior cerebral hypoperfusion were compared among pre-old (≤ 74 years), old (75 to 84 years), and oldest-old (≥ 85 years) subgroups. RESULTS: The oldest-old subgroup showed significantly longer disease duration, lower education level, more severe frailty, less leisure activity, worse cognitive impairment, a tendency of slower progression of cognitive decline, greater MTL atrophy, more severe white matter hyperintensities and infarcts, and lower frequency of posterior hypoperfusion than the younger age subgroups. Regarding the brain imaging subtypes, there were significantly more patients with the limbic-predominant subtype and fewer patients with the hippocampal-sparing subtype in the oldest-old AD group than the pre-old AD group. CONCLUSIONS: Oldest-old patients with AD show different factors and brain imaging features associated with cognition from pre-old and old patients. Our results are expected to provide useful information towards understanding the pathophysiology of oldest-old patients with AD, and for determining their clinical diagnosis and appropriate management methods.

Mechanical thrombectomy for occlusion of the fenestrated middle cerebral artery M1 segment: A case report and review of the literature.

It is impossible to predict underlying anomalies in acute large vessel occlusion and it could be a problem when performing mechanical thrombectomy (MT). We report a case of MT for occlusion of the fenestrated middle cerebral artery (MCA) M1 segment. A 49-year-old woman presented to our hospital with dysarthria and left hemiparesis. Acute ischemic stroke due to right occluded MCA was diagnosed. During performing emergent MT, a part of the M1 segment was revealed to be slit-shaped by digital subtraction angiography, suggesting a fenestrated MCA. The aspiration catheter could not be advanced through the narrow limb of the fenestration, and the distal thrombus was retrieved using a stent retriever, additionally. Postoperatively, the patient's symptoms improved without complications. When occlusion of the fenestrated MCA is suspected, it is necessary to consider converting the strategy from an aspiration catheter alone to the combined use of a stent retriever.

Efficacy and Safety of Dual Antiplatelet Therapy with the Routine Use of Prasugrel for Flow Diversion of Cerebral Unruptured Aneurysms.

PURPOSE: Prasugrel is not approved for patients treated with flow diverters, which have a high metal coverage ratio. However, robust antiplatelet therapy with prasugrel may prevent thromboembolic complications. We administered prasugrel and aspirin to all patients treated with flow diverters and reported the safety of the antiplatelet therapy regimen. METHODS: This retrospective, single-center study evaluated the angiographic and clinical data of consecutive patients treated with flow diverters for cerebral unruptured aneurysms between June 2020 and May 2022. All patients received dual antiplatelet therapy, including prasugrel and aspirin. The administration of prasugrel ended 3 or 6 months after the procedure, whereas aspirin use continued for at least 12 months. Periprocedural complications (< 30 days post-procedure) and delayed complications (> 30 days post-procedure) were recorded. RESULTS: During the study period, 120 unruptured aneurysms were treated with flow diverters in 110 patients. All patients, except one, survived longer than 12 months after the procedure. The rate of thromboembolic complications was 6.4%, and more than half of the patients had transient symptoms; one (0.9%) had a major ischemic stroke. One patient (0.9%) each had an asymptomatic, small subarachnoid hemorrhage and significant hemorrhagic complications with melena. The rate of permanent neurological deficits was 1.8%, and the mortality rate was 0.9%. CONCLUSIONS: Dual antiplatelet therapy comprising routine use of prasugrel and aspirin for flow diverter-implanted patients possibly contributed to a low rate of thromboembolic complications and low risk of hemorrhagic complications.

Validation of Efficacy and Safety of TachoSil ® Tissue Sealant for Vessel Transposition in Microvascular Decompression.

BACKGROUND AND OBJECTIVES: Use of TachoSil ® as the transposition material of microvascular decompression (MVD) for hemifacial spasm (HFS) and trigeminal neuralgia (TN) is easy and safe to perform, but the efficacy and safety of this technique are unknown. This study attempted to validate the efficacy and safety of TachoSil ® as a transposition material of MVD. METHODS: A retrospective study of the surgical results and complications of 63 patients (35 HFS and 28 TN) treated by the TachoSil ® technique between January 2011 and December 2021 was conducted. The efficacy of the treatment was evaluated by Kaplan-Meier survival analysis. Magnetic resonance imaging follow-up study was performed to detect any adverse events including a mass formation. RESULTS: The rate of complete disappearance of HFS was 91.4% at 1 year and estimated to be 85.7% after a 10-year follow-up. The rate of no pain without medication for TN was 85.4% at 1 year and estimated to be 69.0% after a 9-year follow-up. These surgical results are comparable with those previously reported. Flaking of TachoSil ® releasing the offending artery was only recognized in one case (1.6%). Therefore, TachoSil ® can be considered as an effective transposition material for MVD. TachoSil ® did not increase the rate of acute and subacute adverse events such as inflammation and delayed facial palsy. Magnetic resonance imaging follow-up identified no abnormalities including mass that suggested granuloma formation. CONCLUSION: The efficacy of the TachoSil ® technique for HFS and TN and the reliability of TachoSil ® as an adhesive material in MVD were verified. No adverse events associated with TachoSil ® use in MVD were found. We conclude that the TachoSil ® technique has relatively long efficacy and safety for MVD.

Longitudinal patterns of Alzheimer's disease subtypes: A follow-up magnetic resonance imaging and single-photon emission computed tomography study.

AIM: Alzheimer's disease (AD) is a biologically heterogenous disease. In a previous study, we classified 245 patients with probable AD into the typical AD (TAD), limbic-predominant (LP), hippocampal-sparing (HS) and minimal-change (MC) subtypes based on their medial temporal lobe atrophy on magnetic resonance imaging and posterior hypoperfusion on single-photon emission computed tomography, and described differences in clinical features among the patients with different AD subtypes. This study aimed to clarify the longitudinal patterns of changes in patients with the various AD subtypes by follow-up brain imaging analyses. METHODS: Follow-up magnetic resonance imaging or single-photon emission computed tomography data obtained 12-48 months after the first brain imaging were investigated in 79 patients with probable AD, comprising 25 of the TAD subtype, 19 of the LP subtype, 17 of the HS subtype and 18 of the MC subtype. RESULTS: All patients of the TAD subtype remained as the same subtype at follow up. Approximately 37% of patients of the LP subtype and 29% of patients of the HS subtype progressed to the TAD subtype, and 17%, 33% and 6% of the MC subtype progressed to the TAD, LP and HS subtypes, respectively. The group of patients showing subtype progression was associated only with a longer follow-up duration. CONCLUSIONS: There might be different progression patterns and progression rates of changes among the atypical AD subtypes. Further longitudinal brain imaging studies might provide information regarding the pathophysiological association between the various AD subtypes, and might be helpful for determining appropriate therapies and management methods. Geriatr Gerontol Int 2023; 23: 919-924.

Factors influencing early obliteration during flow diverter treatment of cerebral aneurysms: Establishment of an early obliteration inhibition score.

Objective: This retrospective study aimed to investigate factors associated with inhibition of early aneurysm obliteration after flow diverter (FD) treatment. We also created the early obliteration inhibition (EOI) score for pre-operative evaluation. Methods: We examined 110 cerebral aneurysms in 104 patients who underwent FD treatment. The following parameters were investigated: age, sex, symptoms, aneurysm location and type, maximum aneurysm diameter, parent vessel diameter, neck diameter, and dome-neck ratio. We also noted aneurysm location relative to the curvature of the parent artery and any branches arising from the aneurysm dome. Procedural factors such as FD diameter and length, number of FDs placed, type of FD, and use of adjunctive coiling were also investigated. Aneurysm obliteration was evaluated using digital subtraction angiography 3 months after the procedure. Adequate obliteration was defined as grade C or D on the O'Kelly-Marotta scale. Results: The following factors inhibited early obliteration: 1) extradural location, 2) saccular aneurysm, 3) aneurysm neck located at the outer convexity of the parent artery, and 4) arterial branch arising from the aneurysm dome. Odds ratios were used to create an EOI score. Receiver operating characteristic curve analysis showed that the optimal cut-off EOI score for adequate obliteration was 1.5 (area under the curve, 0.81; 95% confidence interval, 0.73-0.9; sensitivity, 0.9; specificity, 0.57). Conclusion: The EOI score, which is based on factors that inhibit early obliteration, may predict early treatment outcomes of FD placement.

Decision-making tree for optimal Woven EndoBridge device sizing with ideal Woven EndoBridge-aneurysm volume (iWAVe) ratio.

PURPOSE: Optimal size selection is important for successful Woven EndoBridge (WEB) treatment. Conventional recommendations for WEB sizing based on aneurysm width and height sometimes require device exchange. We aimed to design a novel volume-based parameter, the ideal WEB-aneurysm volume (iWAVe) ratio, for optimal WEB sizing. METHODS: Consecutive patients who underwent WEB treatment for wide-neck bifurcation aneurysms between January 2021 and May 2022 were retrospectively reviewed. Aneurysm volume was automatically calculated using software. We measured the aneurysm volume based on the expected position of the device within the aneurysm. The WAVe ratio was defined as the ratio of the aneurysm volume to WEB volume. We dichotomized aneurysms treated with a successful sizing or unsuccessful sizing for WEB (successful group and unsuccessful group, respectively). RESULTS: Thirty-five patients were eligible for study enrollment. Ten patients (28.6%) needed to exchange the WEB on the first attempt and required another WEB on the second attempt resulting in deployment success. Hence, 35 aneurysms were in the successful group and 10 were in the unsuccessful group. The median WAVe ratio was 1.0 (range 0.76-1.31) in the successful group and 1.27 (0.58-1.89) in the unsuccessful group. Using logistic regression, iWAVe ratio was from 0.90-1.16 to secure a >80% probability of success by the 95% lower confidence limit. The sensitivity and specificity of the iWAVe ratio for optimal size selection on the first attempt were 0.60 and 1.00, respectively. CONCLUSION: Decision-making based on aneurysm width and the iWAVe ratio could promote optimal WEB sizing.

Persistent contrast-filling in the woven endobridge device three months after its implantation for cerebral aneurysm: Incidence, predictive factors, and outcome.

OBJECTIVE: The Woven EndoBridge (WEB) was developed to treat wide-neck bifurcation intracranial aneurysms. Occasionally, persistent contrast-filling has been observed in the WEB after treatment. The purpose of our study was to investigate its incidence, predictive factors, and clinical impact. METHODS: All patients treated with the WEB between January 2021 and September 2021 at our institute were reviewed. Age, gender, antiplatelet therapy, and angioarchitecture were compared between the persistent-filling group and the no-filling group at the three-month follow-up angiography. RESULTS: We included 20 patients with 20 unruptured aneurysms. Ten of the 20 intracranial aneurysms (50 %) showed contrast-filling in the WEB after three months. Two of the 10 had contrast not only inside, but around the device. Statistically significant differences were observed between the persistent-filling group and the no-filling group in neck size (median: 4.5 mm vs. 3.8 mm), deviation of the aneurysm axis from the inlet flow line where the orifice of the bifurcated arteries overlaps (mean: 15.1° vs. 33.0°), and postoperative dual antiplatelet therapy (DAPT) for at least a month (90 % vs. 20 %). One case had additional coil embolization six months after the WEB implantation. Including this case, one year after the treatment or the re-treatment, the filling in the device had disappeared in nine of 10 cases. No bleeding was observed during the mean follow-up period of 24 months. CONCLUSION: Persistent contrast-filling was associated with postoperative DAPT for at least a month, a wide neck, and less deviation of the aneurysm axis from the inlet flow line. If the contrast-filling is only within the WEB and not between the aneurysmal wall and the WEB, we are not concerned. To further assess the clinical impact of this phenomenon, long-term follow-up will be needed.

Supraorbital keyhole approach for paraclinoid aneurysms clipping: A case series with literature review.

Background: Paraclinoid aneurysms (PcAs) are challenging aneurysms due to the complexity of their relation to the surrounding bony and neurovascular structures. Although over the past decade, their management strategy has shifted from transcranial to endovascular approaches; here, we try to revolve around a subcategory to which minimal invasive supraorbital keyhole (SOK) surgery is feasible depending on specific radiological criteria with a literature review. Methods: A group of unruptured PcAs was managed surgically, with a subset that was clipped through the SOK approach. They were selected by preoperative simulation images using 3D computed tomography (CT) angiography (CTA). We also conducted an extensive literature review based on a database available on PubMed and Google Scholar, the yielded cases from the literature review plus our cases were analyzed according to six parameters including their size, location, dome direction, need for clinoidectomy and proximal cervical control, and surgical outcome. Results: From February 2009 to August 2022, 49 cases of unruptured PcAs were managed by clipping, and of these, four cases were clipped by the SOK approach, in addition, four cases were yielded through the literature review. The sizes of the PcAs ranged from 3 to 8 mm. Their location fluctuated from anterior to the superomedial wall and their domes pointed superiorly except for one which points posteriorly. Six of eight cases required anterior clinoidectomy, the outcome was uneventful. Conclusion: A subset of unruptured PcAs are amenable to SOK with criteria such as unruptured small aneurysm (<10 mm) and projected superiorly. These characteristics can be determined preoperatively using CTA.

Atlantoaxial Stabilization Using C1 Lateral Mass and C2 Pedicle/Translaminar Screw Fixation by Intraoperative C1- and C2-Direct-Captured Navigation with Preoperative Computed Tomography Images.

In C1-C2 posterior fixation, the C1 lateral mass and C2 pedicle/translaminar screw insertion under spine navigation have been used frequently. To avoid the risk of neurovascular damage in atlantoaxial stabilization, we assessed the safety and effectiveness of a preoperative computed tomography (CT) image-based navigation system with intraoperative independent C1 and C2 vertebral registration. It is ideal when a reference frame can be linked directly to the C1 posterior arch for C1-direct-captured navigation, but there is a mechanical challenge. A new spine clamp-tracker system was implemented recently, which allows reliable C1- and C2- direct-captured navigation in nine patients with traumatic C2 fractures. In this way, there was no misalignment of C1-C2 screws. C1 lateral mass screws were used except for one case, and translaminar screws were primarily used as an anchor for C2. The C1 lateral mass screw locations, which are 19 mm laterally from the C1 posterior arch's center, are taken to be constant. However, there is one unusual circumstance in which using a C1 laminar hook instead of a C1 lateral mass screw appears to be a beneficial substitute. The increase of surgical accuracy for posterior C1-C2 screw fixation without cost constraints is significantly facilitated by intraoperative C1- and C2-direct-captured navigation with preoperative computed CT images.

Traumatic rupture of intracranial dermoid cyst with continuous fat droplet migration.

Background: The intracranial dermoid cyst (ICD) can be complicated by rupture and spilling of its contents with potentially dreadful consequences. Head trauma as a predisposing element for this phenomenon is extremely rare. Few reports address the diagnosis and management of trauma-related rupture of ICD. However, there is a pronounced knowledge gap related to the long-term follow-up and the fate of the leaking contents. Here, we present a unique case of traumatic rupture of ICD complicated by continuous fat particle migration within the subarachnoid space with its surgical implications and outcome. Case Description: A 14-year-old girl had an ICD rupture following a vehicle collision. The cyst was located near the foramen ovale with intra and extradural extensions. Initially, we opted to follow the patient clinically and radiologically as she had no symptoms, and the imaging showed no red flags. Over the next 24 months, the patient remained asymptomatic. However, the sequential brain magnetic resonance imaging revealed significant continuous migration of the fat within the subarachnoid space, with the droplets noticed to increase in the third ventricle. That is considered an alarming sign of potentially serious complications impacting the patient's outcome. Based on the above, the ICD was completely resected through an uncomplicated microsurgical procedure. On follow-up, the patient is well, with no new radiological findings. Conclusion: Trauma-related ruptured ICD may have critical consequences. Persistent migration of dermoid fat can be managed with surgical evacuation as a viable option to prevent those potential complications such as obstructive hydrocephalus, seizures, and meningitis.

Glioependymal cyst in the medulla oblongata - A case report.

Background: Glioependymal cysts (GECs) are rare benign lesions that can be found anywhere along the neuroaxis, with most of the reports denoting supratentorial location. Here, we introduce a rare case of successfully treated glioependymal cysts lying in an uncommon location, namely medulla oblongata. Case Description: A 69-year-old lady presented with progressive unsteadiness and swallowing disturbances, and brain magnetic resonance imaging showed a dorsally located lesion within the medulla oblongata; based on the presentation and radiological features, surgical intervention was deemed mandatory. The suboccipital midline approach was used to perform marsupialization of the cyst with shunting through a syringosubarachnoid shunt to prevent future recurrence, and the patient outcome was improved. Conclusion: Medulla Oblongata's location for glioependymal cysts proposed unique diagnostic and operative challenges that may require highlighting for practicing neurosurgeons.

The impact of the approval of prothrombin complex concentrates for vitamin K antagonist-related intracerebral hemorrhage: A retrospective study.

OBJECTIVES: This study aimed to determine the impact of the approval of prothrombin complex concentrates on the treatment of vitamin K antagonist-related intracerebral hemorrhage. MATERIALS AND METHODS: We retrospectively studied all patients with vitamin K antagonist-related intracerebral hemorrhage treated with prothrombin complex concentrate at our institutes between January 2010 and June 2021. Before approval, prothrombin complex concentrate was administered as either 500 or 1000 IU at the physician's discretion (previous dose group). After approval, we adopted the manufacturer's recommended regimen (recommended dose group). The primary outcome was post-administration international normalized ratio. Secondary outcomes were the amount of prothrombin complex concentrate administered and proportion of post-administration international normalized ratio <1.5, hematoma expansion, thrombotic events within 30 days, modified Rankin scale 0-3 at discharge, and in-hospital mortality. RESULTS: Thirty-two and 19 patients in the previous and recommended dose groups, respectively, were included. The post-administration international normalized ratio significantly differed between groups. The prothrombin complex concentrate dose and proportion of patients achieving post-administration international normalized ratio <1.5 were significantly higher in the recommended dose group than in the previous dose group (1500 IU vs. 500 IU, p<0.001 and 100% vs. 68%, p = 0.008). The proportions of hematoma expansion, thromboembolic events, modified Rankin scale 0-3, and mortality did not differ between groups. CONCLUSION: After prothrombin complex concentrate approval, prothrombin time-international normalized ratio correction was more effective with a significant increase in the prothrombin complex concentrates dose for vitamin K antagonist-associated intracerebral hemorrhage; however, there was no apparent difference in clinical outcomes.

Posterior condylar canal dural arteriovenous fistula treated with transvenous embolization through the deep cervical vein.

The posterior condylar vein is an emissary vein that connects the extracranial and intracranial venous systems through the posterior condylar canal (PCC). Dural arteriovenous fistulas (DAVF) of the PCC are rare, and only seven cases have been reported. Transvenous embolization (TVE) is the first-line treatment for PCC DAVF and is predominantly performed through the internal jugular vein. Herein, we report a case of PCC DAVF treated with TVE through the deep cervical vein. This is the first case report of a PCC DAVF treated with TVE through the deep cervical vein.

Delays in initial workflow cause delayed initiation of mechanical thrombectomy in patients with in-hospital ischemic stroke.

Objectives: The benefit of mechanical thrombectomy for acute ischemic stroke is highly time dependent. However, time to treatment is longer for in-hospital stroke patients than community-onset stroke patients. This study aimed to clarify the cause of this difference. Methods: A retrospective single-center study was performed to analyze patients with large vessel occlusion who underwent mechanical thrombectomy between January 2017 and December 2019. Patients were divided into in-hospital stroke and community-onset stroke groups. Clinical characteristics and treatment time intervals were compared between groups. Results: One hundred four patients were analyzed: 17 with in-hospital stroke and 87 with community-onset stroke. Patient characteristics did not significantly differ between groups. Median door (stroke recognition)-to-computed tomography time (36 min vs. 14 min, P<0.01) and door-to-puncture time (135 min vs. 117 min, P=0.02) were significantly longer in the in-hospital stroke group than the community-onset stroke group. However, median computed tomography-to-puncture time (104 min vs. 104 min, P=0.47) and puncture-to-reperfusion time (53 min vs. 38 min, P=0.17) did not significantly differ. Conclusions: Longer door-to-puncture time in in-hospital stroke patients was mostly caused by longer door-to-computed tomography time, which is the initial part of the workflow. An in-hospital stroke protocol that places importance on early stroke specialist consultation and prompt transportation to the computed tomography scanner might hasten treatment and improve outcomes in patients with in-hospital stroke.

Early spontaneous occlusion of a vertebral artery dissecting aneurysm caused by subarachnoid hemorrhage: A case report.

We report a case of vertebral artery dissecting aneurysm (VADA) that developed with subarachnoid hemorrhage and was found to be occluded based on subsequent digital subtraction angiography. Few reports have been published on ruptured VADA in which ipsilateral vertebral arteries are occluded. The proper management of this type of aneurysm is controversial. A 44-year-old woman developed a sudden onset headache. Computed tomography and three-dimensional computed tomography were immediately performed and showed subarachnoid hemorrhage and VADA distal to the right posterior inferior cerebellar artery bifurcation. We decided to treat the VADA immediately and performed digital subtraction angiography but found the VADA had spontaneously occluded. We performed coil embolization, including the aneurysm and the parent artery, with reference to the findings of three-dimensional computed tomography. On Day 16, recurrence was considered due to the finding of dilation of the distal end where the coil was embolized. An additional embolization was performed via the posterior communicating artery. No cases of endovascular treatment have been reported in VADA cases in which the rupture site is spontaneously occluded. In such cases, the treatment may be incomplete, so strict follow-up is required.

Characterization of Alzheimer's Disease Subtypes Based on Magnetic Resonance Imaging and Perfusion Single-Photon Emission Computed Tomography.

BACKGROUND: Alzheimer's disease (AD) is a biologically heterogenous disease. Previous studies have reported the existence of various AD subtypes, and the various clinical features of the subtypes. However, inconsistent results have been obtained. OBJECTIVE: To clarify the clinical characteristics of the various AD subtypes, by classifying probable AD into subtypes based on magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) findings. METHODS: A total of 245 patients with probable AD were classified into the typical AD (TAD) subtype, limbic-predominant (LP) subtype, hippocampal-sparing (HS) subtype, and minimal-change (MC) subtype, based on the presence of medial temporal lobe atrophy on MRI and posterior cerebral hypoperfusion on SPECT. Demographics, including age, sex, body mass index, disease duration, education years, comorbidities, frailty, leisure activity, and neuropsychological findings were compared between the AD subtypes. RESULTS: he frequency of TAD, LP, HS, and MC subtypes was 49%, 20%, 18%, and 13%, respectively. Patients with the LP subtype were older and characterized by fewer major comorbidities, higher frailty, and slower progression of disease. Patients with the HS subtype were younger and characterized by shorter disease duration, lower frailty, and preserved memory, but had prominent constructional dysfunction. Patients of the MC subtype were characterized by shorter disease duration, lower education level, less leisure activity, less impaired memory and orientation, and slower progression. CONCLUSION: Patients with different AD subtypes differed in their demographic and clinical features. The characterization of patients' AD subtypes may provide effective support for the diagnosis, treatment, and care of AD patients.

Brainstem Infarctions Caused by a Proximal Marker of the PulseRider Device Obstructing the Origin of a Perforator.

The PulseRider (Cerenovus, Johnson & Johnson Medical Devices, New Brunswick, NJ, USA) is a neck reconstruction device that is used for the treatment of unruptured wide-necked bifurcation aneurysms. Herein, we describe the case of a 51-year-old male patient with a basilar apex aneurysm who was treated with PulseRider but had post-procedural brainstem infarctions caused by one of the proximal markers covering the origin of a perforator. In such cases, repositioning of the PulseRider should be performed to avoid infarctions.

Keyhole Approach in Cerebral Aneurysm Surgeries.

Pterional approach via standard fronto-temporal craniotomy and interhemispheric approach via bifrontal craniotomy are the gold standards for clipping of cerebral aneurysms in the anterior circulation. Endovascular treatment is now widely used, but subsets of aneurysms are still indicated for surgical clipping. Modern technological advances allow less invasive clipping techniques such as the keyhole approach. This chapter discusses the surgical indications, preoperative simulation, surgical techniques, and pros and cons of keyhole (supraorbital) clipping. Selection of standard craniotomy or keyhole craniotomy should be uncontroversial, but keyhole clipping requires definite surgical indications based on the characteristics of the target aneurysm for safe clipping.

Staged Hybrid Techniques With Straightforward Bypass Surgery Followed by Flow Diverter Deployment for Complex Recurrent Middle Cerebral Artery Aneurysms.

BACKGROUND: Recurrent complex middle cerebral artery (MCA) aneurysms after combined clipping and endovascular surgery are challenging, and if conventional techniques are adapted, advanced surgical, endovascular, and a combination of both techniques are often required. For such complex aneurysms, safe and effective straightforward techniques for all neurovascular surgeons are warranted. We describe the details of staged hybrid techniques with straightforward bypass surgery followed by flow diverter deployment in a patient with complex MCA aneurysm. ILLUSTRATIVE CASE: A 69-year-old woman presented with left recurrent large MCA aneurysm enlargement 25 years after direct surgery and coil embolization for ruptured aneurysm. The recurrent MCA aneurysm had large and complex morphology and was adhering to the brain tissues. Therefore, it was unsuitable to treat such aneurysm with conventional surgical and endovascular techniques with a high risk of morbidity. We performed (1) M2 ligation following superficial temporal artery-M2 bypass and (2) flow diverter deployment assisted with coil packing in two sessions. Three months after the second session, the aneurysm was completely occluded with endothelialization of the neck. Angiographic findings revealed no recurrence 12 months after the treatment. CONCLUSIONS: Staged hybrid techniques with straightforward bypass surgery followed by flow diverter deployment may be a safe and effective treatment for complex recurrent MCA aneurysms.