[Kamiyama-Style STA-MCA Bypass Surgery].

The primary objective of bypass surgery is the long-term patency of bypass vessels, but shortening occlusion time during anastomosis is also required to avoid ischemic complications. Bypass surgery is associated with variations in the procedure depending on a surgeon's preference. However, regardless of technical variations, success of bypass surgery depends on some universal aspects. Surgical field preparation before anastomosis and implementation of adequate steps for confirmation of the procedure are important determinants of a successful bypass surgery.

Evaluation of the hemostatic effect of a combination of hemostatic agents and fibrin glue in a rabbit venous hemorrhage model.

BACKGROUND: In neurosurgery, it is important to use local hemostatic agents. We have explored a more powerful method of hemostasis by the combination of commercially available hemostatic agents with fibrin glue in the hopes of synergistic effects. METHOD: A bleeding model was constructed by puncturing the rabbit posterior vena cava with a needle. After applying the sample to the bleeding point, compression was performed for 10 s. If temporary hemostasis was achieved after pressure release, a 30 s wash was performed to confirm that ultimate hemostasis was achieved. Up to three hemostasis attempts were performed on the same bleeding point until hemostasis was achieved, and the number of attempts required for hemostasis was counted. If hemostasis was not achieved after three attempts, it was counted as four times. Four groups were evaluated: (1) gelatin sponge alone, (2) gelatin sponge + fibrin glue, (3) oxidized cellulose alone, and (4) oxidized cellulose + fibrin glue; each group was tested 16 times. RESULTS: The median value (range minimum value-maximum value) of the number of hemostatic attempts in Group 1 to Group 4 was 3 (1-4), 1 (1-1), 4 (4-4), and 4 (2-4). In Group 2, there were two test exclusions owing to deviations of the test procedure. CONCLUSIONS: The compatibility of gelatin sponge and fibrin glue was very good, with a very strong and rapid hemostatic effect compared to other methods, showed its usefulness. This combination method may be effective for a variety of venous hemorrhages in neurosurgery.

ADAPT First-Line Strategy for MCA Mainstem Occlusion; Analysis for Optimal Salvage Therapy and its Related Factor.

OBJECTIVES: A direct first-pass aspiration technique (ADAPT) is an attractive interventional technique for mechanical thrombectomy (MT), which could achieve recanalization quickly and safely at a small amount of material resources. To clarify its usefulness, our ADAPT first-line strategy for middle cerebral artery (MCA)-mainstem occlusion was retrospectively analyzed. MATERIALS AND METHODS: We reviewed 54 consecutive patients who underwent MT for MCA-mainstem occlusion using ADAPT first-line strategy. A salvage procedure was concurrently conducted in cases that failed to achieve successful recanalization by ADAPT attempt alone. Procedural and clinical outcome were assessed in both ADAPT alone and Salvage groups. Further investigation was performed in cases that required salvage procedure to determine the reason, risk factors, and optimal procedure. RESULTS: Forty-one patients (75.9%) were able to achieve successful recanalization with ADAPT technique alone. In salvage group, the procedural time was longer, and rates of successful recanalization were lower than in ADAPT-alone group. No significant difference in the rates of favorable outcomes was observed. Among 13 patients who required salvage therapy, the major reason (eight cases) was intra-procedural "thrombus distal migration". Failure of recanalization was seen in two cases due to "inaccessibility". In patients who had "thrombus distal migration", occlusion in the proximal portion was more frequently observed than in patients who did not (p = 0.032, 63.6% vs. 23.3%). CONCLUSIONS: Our ADAPT first-line strategy for MCA-mainstem occlusion demonstrated favorable procedural and clinical outcomes, even in cases that required additional procedures. Further investigation and better understanding are required to refine this promising procedure.

A Direct Aspiration First Pass Technique for Vertebra-Basilar Occlusion: A Retrospective Comparison to Stent Retriever.

OBJECTIVES: This study aimed to assess the clinical usefulness of a direct aspiration first pass technique as a first-line strategy for mechanical thrombectomy in posterior circulation. MATERIALS AND METHODS: We examined 34 consecutive patients treated with mechanical thrombectomy for acute vertebrobasilar artery occlusion. Procedural and clinical outcomes were assessed and compared between patients treated with a direct aspiration first pass technique first-line strategy (ADAPT group) and stent retriever system first-line strategy (stent retriever group). RESULTS: Overall, successful reperfusion, complete reperfusion, and first-pass effects were achieved in 94.1%, 61.8%, and 50% of patients with acute ischemic stroke in vertebra-basilar artery occlusion treated with mechanical thrombectomy, respectively. The ADAPT group required a significantly shorter procedural time (p=.015) and fewer attempts (p=.0498) to achieve successful recanalization than the stent retriever group. The ADAPT group also tended to show better recanalization rates and first-pass effects than the stent retriever group. The rates of favorable outcomes seemed to be better, although insignificant, in the ADAPT group than in the stent retriever group (52.2% vs. 27.3%, p=.217). However, a significant correlation between the time required for reperfusion and clinical outcome was detected, and this will serve as the rationale for encouraging a direct aspiration first pass technique as a first-line strategy in the acute vertebra-basilar artery. CONCLUSIONS: The a direct aspiration first pass technique first-line strategy for mechanical thrombectomy in posterior circulation may achieve successful recanalization with fewer attempts and shorter durations than the stent retriever first-line strategy.

Eicosapentaenoic acid prevents the progression of intracranial aneurysms in rats.

BACKGROUND: As subarachnoid hemorrhage due to rupture of an intracranial aneurysm (IA) has quite a poor outcome despite of an intensive medical care, development of a novel treatment targeting unruptured IAs based on the correct understanding of pathogenesis is mandatory for social health. METHODS: Using previously obtained gene expression profile data from surgically resected unruptured human IA lesions, we selected G-protein coupled receptor 120 (GPR120) as a gene whose expression is significantly higher in lesions than that in control arterial walls. To corroborate a contribution of GPR120 signaling to the pathophysiology, we used an animal model of IAs and examine the effect of a GPR120 agonist on the progression of the disease. IA lesion was induced in rats through an increase of hemodynamic stress achieved by a one-sided carotid ligation and induced hypervolemia. Eicosapentaenoic acid (EPA) was used as an agonist for GPR120 in this study and its effect on the size of IAs, the thinning of media, and infiltration of macrophages in lesions were examined. RESULT: EPA administered significantly suppressed the size of IAs and the degenerative changes in the media in rats. EPA treatment also inhibited infiltration of macrophages, a hallmark of inflammatory responses in lesions. In in vitro experiments using RAW264.7 cells, pre-treatment of EPA partially suppressed lipopolysaccharide-induced activation of nuclear factor-kappa B and also the transcriptional induction of monocyte chemoattractant protein 1 (MCP-1), a major chemoattractant for macrophages to accumulate in lesions. As a selective agonist of GPR120, TUG-891, could reproduce the effect of EPA in RAW264.7 cells, EPA presumably acted on this receptor to suppress inflammatory responses. Consistently, EPA remarkably suppressed MCP-1 expression in lesions, suggesting the in vivo relevance of in vitro studies. CONCLUSIONS: These results combined together suggest the potential of the medical therapy targeting GPR120 or using EPA to prevent the progression of IAs.

Recurrence of surgically treated parasagittal meningiomas: a meta-analysis of risk factors.

BACKGROUND: As the predictive role of many risk factors for parasagittal meningioma (PM) recurrence remains unclear, the objective of the meta-analysis was to make a comprehensive assessment of the predictive value of selected risk factors in these lesions. METHODS: Studies including data on selected risk factors, such as histology, tumor and sinus resection, sinus invasion, tumor localization, and immediate postoperative radiotherapy for PMs recurrence, were searched in the NCBI/NLM PubMed/MEDLINE, EBM Reviews/Cochrane Central, ProQuest, and Scopus databases, and analyzed using random effects modeling. RESULTS: Thirteen observational studies involving 1243 patients met the criteria for inclusion in the meta-analysis. WHO grading of meningiomas was identified as the most powerful risk factor for recurrence. WHO grade II meningiomas (OR 11.61; 95% CI 4.43-30.43; P < .01; I2 = 31%) or composite group of WHO grades II and III (OR 14.84; 95% CI 5.10-43.19; P < .01; I2 = 48%) had a significantly higher risk of recurrence than benign lesions. Moreover, an advanced sinus involvement (types IV-VI according to the Sindou classification) (OR 3.49; 95% CI 1.30-9.33; P = .01; I2 = 0%) and partial tumor resection (Simpson grades III-V) (OR 2.73; 95% CI 1.41-5.30; P = .03; I2 = 52%) were associated with a significantly higher risk of recurrence than their counterparts. CONCLUSION: Among the selected risk factors, high-grade WHO lesions, advanced sinus invasion, and partial tumor resection were associated with a higher risk of PM recurrence, with WHO grading system being the most powerful risk factor.

Medullary Compression Due to Ectatic Vertebral Artery-Case Report and Review of Literature.

Medullary compression syndrome due to anomalous course of blood vessels is a rare disease most commonly seen in the adult population. The offending vessels causing this syndrome are mostly posterior inferior cerebellar artery or the vertebral artery. The symptoms of this syndrome vary from most common hypertension to various other neurologic deficits like hemiplegia, dysesthesia, and dysarthria. Intractable dizziness is a rare symptom of this disease. The definite management plan for this disease is microvascular decompression. We present our case of medullary compression syndrome which manifested as intractable dizziness. We describe our experience in the management of this patient as well as present a review of literature of this rare disease.

Safe and bloodless exposure of the third segment of the vertebral artery: a step-by-step overview based on over 50 personal cases.

Craniovertebral junction surgery usually requires the exposure of the third segment of the vertebral artery (V3). However, the complexity of musculature, a relatively high incidence of anomalies in the course of the vertebral artery (VA), and the presence of a rich venous plexus in this region make the V3 exposure challenging with a high risk of serious complications while taking down the suboccipital muscles in a single layer. A muscle dissection in interfascial layers, however, overcomes the drawbacks inherent in a blind dissection of the V3 as each of the muscles represents substantial landmark aiding subsequent step of the procedure and thus helping identify underlying anatomical structure early and safely. Moreover, along with a bloodless VA dissection off its surrounding venous plexus, it permits a safe and comfortable V3 exposure during the surgically demanding procedures.

State-of-art in surgical treatment of dissecting posterior circulation intracranial aneurysms.

Vertebrobasilar (VB) intracranial dissecting aneurysms (IDAs) pose difficult therapeutic issues and are especially among the most difficult to manage surgically. There are, however, some cases where selective aneurysm obliteration by endovascular approach is impossible or is associated with an unacceptable risk of morbidity. This is particularly true when the aneurysm is dissecting, giant, or has a large neck. In such cases, surgical treatment may be the only alternative. Optimal management of these lesions is therefore challenging and treatment decisions have to be made on a case-by-case basis. Ideal treatment should be a complete surgical excision of the lesion; however, this procedure might only be possible after distal and proximal vessel wall occlusion which might not be tolerated by the patient depending on the location of the aneurysm. Therefore, formulation of recommendations concerning the surgical strategy remains still difficult due to inconsistency of surgical outcomes. The literature describing surgical strategy of VB IDAs is varying in quality and content, and many studies deal with only a few patients. In the presented review, the authors summarize the current knowledge on the incidence, pathogenesis, clinical presentation, and diagnostic procedures with special emphasis on surgical treatment of IDAs in posterior circulation.

Management strategy for bilateral complex vertebral artery aneurysms.

Bilateral complex vertebral artery aneurysms (BCoVAAns) have no established strategy of management. We retrospectively reviewed five consecutive patients with unruptured BCoVAAns between January 2006 and December 2012. Considering surgical risks of lower cranial nerve (LCN) injuries and eventual growth of an opposite side lesion after unilateral vertebral artery (VA) occlusion, we proposed a strategy of combined open and interventional treatment using revascularization. We applied the following several specific techniques: (1) proximal clipping and occipital artery-posterior inferior cerebellar artery (OA-PICA) and/or superficial temporary artery (STA)-superior cerebellar artery (SCA) bypasses; (2) Distal blood pressure, motor evoked potentials (MEPs), and somatosensory evoked potentials (SEPs) monitoring after parent artery temporary occlusion for safe permanent occlusion of the proximal portions of VA and PICA; (3) V3 to V4 bypass using radial artery (RA) graft with proximal clipping or trapping, two of them combined with OA-PICA bypass; (4) VA fenestration as an opportunity to preserve the flow of the parent artery. Two patients were treated bilaterally and 3 unilaterally, with modified Rankin scale assessed at 39 months postoperatively in average 0 in 2, 1 in 2, and 2 in 1, respectively, and the untreated opposite side lesions without regrowth or bleeding. Two patients with patent V3-RA-V4 bypass complained of dysphagia due to LCN palsies. One of them however suffered a cerebellar infarction due to occlusion of the OA-PICA bypass. When BCoVAAns require surgical treatment, revascularization or preservation of the VA should be considered at the first operation. By doing so, the opposite aneurysm can be effectively occluded by coil embolization, even with VA sacrifice if required.

A submucosal esophageal fish bone foreign body surgically removed using intraoperative ultrasonography.

A 68 year-old female was referred to our department with a history of swallowing a fish bone, she reported continuous pain when swallowing. The bone was not evident on endoscopic examination; however, on CT scans a foreign body was identified in the upper esophagus. The bone was buried in the mucosa of the upper esophagus and an emergent rigid esophagoscopy was performed under general anesthesia in order to remove it. The fish bone was successfully removed with the use of intraoperative cervical ultrasonography.

An Autopsy Case of COVID-19 with New Diffuse Pulmonary Ossification.

We present the case of a 61-year-old man who developed coronavirus disease 2019 (COVID-19) and died during treatment for relapsing polychondritis. The patient was intubated and treated with steroid pulse therapy, remdecivir, antibacterial agents, baricitinib, and tocilizumab. However, his respiratory condition worsened, and he died 108 days after disease onset. An autopsy revealed diffuse alveolar damage in the fibrotic phase in all lung lobes, diffuse pulmonary ossification, and cytomegalovirus-infected cells in the middle lobe of the right lung. We herein discuss the clinical features and pathological findings of COVID-19 in immunosuppressed patients.

Cardiac Tamponade as an Initial Manifestation of Diffuse Large B-cell Lymphoma One Year after IgG4-related Disease in Remission.

A 65-year-old man with multiple lymphadenopathies was diagnosed with IgG4-related disease (IgG4-RD) based on findings of a cervical lymph node biopsy and an elevated serum IgG4 level. Treatment was initiated after the onset of autoimmune pancreatitis, and he achieved remission. He developed diffuse large B-cell lymphoma one year later. Pericardial involvement of lymphoma resulted in cardiac tamponade, and he died before histopathological confirmation of lymphoma was made due to a lethal arrhythmia caused by massive involvement of lymphoma into the myocardium. Because patients with IgG4-RD might have an increased risk of malignant diseases, including lymphoma, histopathological examinations should be considered at any time during the course of IgG4-RD.

Allogeneic Stem Cell Therapy for Acute Ischemic Stroke: The Phase 2/3 TREASURE Randomized Clinical Trial.

Importance: Cell therapy is a promising treatment approach for stroke and other diseases. However, it is unknown whether MultiStem (HLCM051), a bone marrow-derived, allogeneic, multipotent adult progenitor cell product, has the potential to treat ischemic stroke. Objective: To assess the efficacy and safety of MultiStem when administered within 18 to 36 hours of ischemic stroke onset. Design, Setting, and Participants: The Treatment Evaluation of Acute Stroke Using Regenerative Cells (TREASURE) multicenter, double-blind, parallel-group, placebo-controlled phase 2/3 randomized clinical trial was conducted at 44 academic and clinical centers in Japan between November 15, 2017, and March 29, 2022. Inclusion criteria were age 20 years or older, presence of acute ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score of 8-20 at baseline), confirmed acute infarction involving the cerebral cortex and measuring more than 2 cm on the major axis (determined with diffusion-weighted magnetic resonance imaging), and a modified Rankin Scale (mRS) score of 0 or 1 before stroke onset. Data analysis was performed between May 9 and August 15, 2022. Exposure: Patients were randomly assigned to either intravenous MultiStem in 1 single unit of 1.2 billion cells or intravenous placebo within 18 to 36 hours of ischemic stroke onset. Main Outcomes and Measures: The primary end points were safety and excellent outcome at day 90, measured as a composite of a modified Rankin Scale (mRS) score of 1 or less, a NIHSS score of 1 or less, and a Barthel index score of 95 or greater. The secondary end points were excellent outcome at day 365, mRS score distribution at days 90 and 365, and mRS score of 0 to 1 and 0 to 2 at day 90. Statistical analysis of efficacy was performed using the Cochran-Mantel-Haenszel test. Results: This study included 206 patients (104 received MultiStem and 102 received placebo). Their mean age was 76.5 (range, 35-95) years, and more than half of patients were men (112 [54.4%]). There were no between-group differences in primary and secondary end points. The proportion of excellent outcomes at day 90 did not differ significantly between the MultiStem and placebo groups (12 [11.5%] vs 10 [9.8%], P = .90; adjusted risk difference, 0.5% [95% CI, -7.3% to 8.3%]). The frequency of adverse events was similar between treatment groups. Conclusions and Relevance: In this randomized clinical trial, intravenous administration of allogeneic cell therapy within 18 to 36 hours of ischemic stroke onset was safe but did not improve short-term outcomes. Further research is needed to determine whether MultiStem therapy for ischemic stroke has a beneficial effect in patients who meet specific criteria, as indicated by the exploratory analyses in this study. Trial Registration: ClinicalTrials.gov Identifier: NCT02961504.

Spontaneous Cerebrospinal Fluid Leakage at the Clivus: Minimally Invasive Surgery Without External Autograft Harvesting.

Spontaneous cerebrospinal fluid (CSF) leakage at the clivus is rare. In previous reports, reconstructive materials used to treat such leakage were typically autografts. Considering the pathology, rigid reconstruction is preferred. We here describe a case of spontaneous CSF leakage at the clivus with multiple bony defects. In this case, in addition to using artificial material instead of autografts, such as fat or fascia, that require additional extranasal invasive harvesting site, a rigid material layer of septal cartilage and bone was also used, enabling more stable multilayer reconstruction. One month postoperatively, computed tomography revealed that the bony defect at the clivus had been well reconstructed. All nasal structures were preserved, and the nasoseptal flap was well engrafted. At eight months post-surgery, the patient remained in good condition. This method allows minimally invasive repair of the leaking clivus, according to the underlying pathophysiology.

Possible Delayed Foreign Body Reactions against Titanium Clips and Coating Materials after Unruptured Cerebral Aneurysm Surgery.

Delayed foreign body reactions to either or both clipping and coating materials have been reported in several small series; however, studies in the titanium clip era are scarce. This study aims to survey the contemporary status of such reactions to titanium clips and coating materials. Among patients who received a total of 2327 unruptured cerebral aneurysmal surgeries, 12 developed delayed intraparenchymal reactions during outpatient magnetic resonance imaging (MRI) follow-up. A retrospective investigation was conducted. The patients' average age was 58.6 (45-73) years, and 11 were women. The aneurysms were located in the middle cerebral artery (n = 7), internal carotid artery (n = 4), or anterior communicating artery (AComA, n = 1). In 10 patients, additional coating with tiny cotton fragments was applied to the residual neck after clipping with titanium clips; however, only the clipping with titanium clips was performed in the remaining two. The median time from surgery to diagnosis was 4.5 (0.3-60) months. Seven (58.3%) patients were asymptomatic, and three developed neurological deficits. MRI findings were characterized by a solid- or rim-enhancing lobulated mass adjacent to the clip with surrounding parenchymal edema. In 11 patients, the lesions reduced in size or disappeared; however, in one patient, an AComA aneurysm was exacerbated, necessitating its removal along with optic nerve decompression. In conclusion, cotton material is a strongly suspected cause of delayed foreign body reactions, and although extremely rare, titanium clips alone may also induce such a reaction. The prognosis is relatively good with steroid therapy; however, caution is required when the aneurysm is close to the optic nerve, as in AComA aneurysms.

Closure of spontaneous cerebrospinal fluid leakage via fistula at the lateral wall of the sphenoid sinus using a bone pile.

This report describes a case of spontaneous cerebrospinal fluid leak through a narrow canal-like fistula in the lateral wall of the sphenoid sinus, which was managed through rigid reconstruction. Rigid reconstruction of the skull base was performed by fitting a pile-shaped bone into the fistula like the pile-driving technique.

Neuroendocrine Carcinoma at the Sphenoid Sinus Misdiagnosed as an Olfactory Neuroblastoma and Resected Using High-Flow Bypass.

In the diagnosis of olfactory neuroblastoma (ONB), the presence of S-100-positive sustentacular cells surrounding the tumor is important; however, these are also present in normal nasal sinus epithelium. Although ONB often has a different final diagnosis, complete resection of the tumor has a good prognosis and minimally affects the patient's treatment plan. When the tumor extends around the internal carotid artery (ICA), complete resection is difficult due to the high risk of vascular injury; revascularization using high-flow bypass can avoid this complication. In the present case, the tumor was located in the left sphenoid sinus and extended around the ICA. Preoperative biopsy tissue was positive for neuroendocrine markers and slightly positive for S-100 protein, leading to a diagnosis of ectopic ONB. High-flow bypass revascularization with trapping of the ICA allowed complete tumor resection. The postoperative histopathological diagnosis was neuroendocrine carcinoma, showing no S-100 protein-positive cells. There was no sign of recurrence at 30 months after surgery without additional treatment. This case demonstrates that the presence of S-100 protein-positive cells in ONB may be misleading. Although misdiagnosis of ectopic ONB should be anticipated, a complete resection of the tumor is an effective treatment strategy.

Effects of clazosentan on cerebral vasospasm-related morbidity and all-cause mortality after aneurysmal subarachnoid hemorrhage: two randomized phase 3 trials in Japanese patients.

OBJECTIVE: Clazosentan has been investigated globally for the prevention of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). The authors evaluated its effects on vasospasm-related morbidity and all-cause mortality following aSAH in Japanese patients. METHODS: Two similar double-blind, placebo-controlled phase 3 studies were conducted in 57 Japanese centers in patients with aSAH, after aneurysms were secured by endovascular coiling in one study and surgical clipping in the other. In each study, patients were randomly administered intravenous clazosentan (10 mg/hr) or placebo (1:1) starting within 48 hours of aSAH and for up to 15 days after aSAH. Stratified randomization based on World Federation of Neurosurgical Societies grade was performed using a centralized interactive web response system. Vasospasm-related morbidity and all-cause mortality within 6 weeks post-aSAH, including new cerebral infarcts and delayed ischemic neurological deficits as well as all-cause mortality, were the first primary endpoint in each study. The second primary endpoint was all-cause morbidity (new cerebral infarct or delayed ischemic neurological deficit from any causes) and all-cause mortality (all-cause morbidity/mortality) within 6 weeks post-aSAH. The incidence of individual components of the primary morbidity/mortality endpoints within 6 weeks and patient outcome at 12 weeks post-aSAH (including the modified Rankin Scale scores) were also evaluated. The above analyses were also performed in the population pooled from both studies. RESULTS: In each study, 221 patients were randomized and 220 were included in the full analysis set of the primary analysis (109 in each clazosentan group, 111 in each placebo group). Clazosentan significantly reduced the incidence of vasospasm-related morbidity and all-cause mortality after aneurysm coiling (from 28.8% to 13.6%; relative risk reduction 53%; 95% CI 17%-73%) and after clipping (from 39.6% to 16.2%; relative risk reduction 59%; 95% CI 33%-75%). All-cause morbidity/mortality and poor outcome (dichotomized modified Rankin Scale scores) were significantly reduced by clazosentan after preplanned study pooling. Treatment-emergent adverse events were similar to those reported previously. CONCLUSIONS: Clazosentan significantly reduced the combined incidence of vasospasm-related morbidity and all-cause mortality post-aSAH with no unexpected safety findings. Clinical trial registration nos.: JapicCTI-163368 and JapicCTI-163369 (https://www.clinicaltrials.jp).

Effects of clinical outcomes by modification of patient selection protocol based on premorbid independence for mechanical thrombectomy in older adult patients.

OBJECTIVES: Since the beneficial effect attained by mechanical thrombectomy (MT) seems to be worse in older than in the younger population, the establishment of an ideal and distinctive patient selection protocol in older is warranted. Herein, we modified our patient selection protocol based on age and premorbid independence in older adult patients. MATERIALS AND METHODS: We retrospectively reviewed 141 consecutive patients with acute ischemic stroke who were treated with MT between 2015 and 2020. We started to restrict the indication of MT in very old patients (≥85-year-old) with severe premorbid functional independence (≥modified Rankin Scale [mRS] 3) in 2018. Clinical outcomes before the modification of protocol (period 1) were compared to after (period 2). RESULTS: Although there were no significant differences in median mRS at 90 days and the rates of favorable outcomes (mRS 0-2) between both periods, rates of poor outcomes (mRS 5, 6) significantly decreased (37.3% vs. 19.7%, P = 0.021) during period 2 compared with period 1. For older adults (≥80-year-old), median mRS was significantly better (P = 0.012) during period 2 than period 1. During period 1, rates of favorable outcomes were significantly lower (P = 0.004) in older than in younger. However, this significant difference was diminished (P = 0.28) during period 2. CONCLUSION: Our modified patient selection protocol in older adults, not only limited by age but also premorbid function, improved the therapeutic outcome of MT. In rapidly aging society, further investigations facilitating a better understanding are necessary to establish an optimal patient selection protocol.