Thromboelastography 6s for assessment of platelet function during coil embolization of unruptured intracranial aneurysms.

OBJECTIVES: Methods for assessing platelet function in patients with neurovascular disease remain controversial and poorly studied. This study aimed to assess associations between thromboelastography 6s (TEG6s) measurements and postoperative ischemic complications in patients with unruptured intracranial aneurysms (UIAs) treated by coil embolization. METHODS: Eighty-four patients with UIAs taking a combined aspirin and clopidogrel protocol were retrospectively reviewed from January 2021 to May 2022. Blood samples were obtained for TEG6s to assess platelet function on the day of coil embolization. To identify acute ischemic complications, diffusion-weighted imaging (DWI) was performed within 24 h after coil embolization. Multivariate logistic regression analysis was conducted to identify potential risk factors for postoperative positive DWI (DWI (+)) lesions. RESULTS: Forty-three of the 84 patients (51%) with DWI (+) lesions were identified. Compared with patients without DWI (+) lesions, Adenosine diphosphate (ADP)-induced platelet-fibrin clot strength (MAADP) was significantly higher (53.6 mm [Interquartile range (IQR): 48.3-58.3 mm] vs 46.7 mm [IQR: 36.8-52.2 mm]; p=0.001) and ADP inhibition rate (ADP%) was significantly lower (19% [IQR: 11-31%] vs 31% [IQR: 21-44%]; p=0.001) in DWI (+) patients. Multivariate analysis identified MAADP, ADP%, and procedure time as significant independent predictors of subsequent DWI (+) lesions (odds ratios: 1.07, 0.96, and 1.02, respectively). Based on receiver operating characteristic curve analysis, MAADP >50.9 mm and ADP% <28.8% were associated with postoperative DWI (+) lesions in patients undergoing coil embolization for UIAs. CONCLUSIONS: MAADP and ADP% as assessed by TEG6s can offer reliable parameters to predict postoperative ischemic complications after coil embolization of UIAs. Lower MAADP values and higher ADP% may decrease the risk of postoperative ischemic complications.

Surgical aspects using an exoscope for corpus callosotomy: initial experience for epilepsy surgery.

The exoscope is a new form of optic device that has begun to be used in the last decade. The exoscope provides high-quality magnification and illumination at depth, allowing easy manipulation of surgical instruments even in narrow surgical fields. Exoscopic corpus callosotomy (CC) has not been reported. We report herein our initial experience with the utility of exoscopic CC. A 3-year-old boy diagnosed with West syndrome at 4 months old was referred to our hospital. As the seizure spasms were considered to carry a risk of severe traumatic injury, we performed exoscopic CC as palliative therapy. An EX VITOM 3D exoscope and 4K-3D surgical monitor were used during the procedure. No surgical complications that could be related to exoscope use were noted. Operative time for exoscopic CC was comparable to that for microscopic CC, despite a lack of previous experience with the equipment. Stereoscopic vision was easily obtained. The exoscope was perceived as providing higher quality magnification. We report our first clinical experience of exoscopic CC. The exoscope appears useful in the field of epilepsy surgery.

Experience using mTOR inhibitors for subependymal giant cell astrocytoma in tuberous sclerosis complex at a single facility.

BACKGROUND: Subependymal giant cell astrocytoma (SEGA) is occasionally seen in tuberous sclerosis complex (TSC). Two main options are currently available for treating SEGA: surgical resection or pharmacotherapy using mammalian target of rapamycin inhibitors (mTORi). We hypothesized that opportunities for surgical resection of SEGA would have reduced with the advent of mTORi. METHODS: We retrospectively reviewed the charts of patients treated between August 1979 and July 2020, divided into a pre-mTORi era group (Pre-group) of patients treated before November 2012, and a post-mTORi era group (Post-group) comprising patients treated from November 2012, when mTORi became available in Japan for SEGA. We compared groups in terms of treatment with surgery or mTORi. We also reviewed SEGA size, rate of acute hydrocephalus, recurrence of SEGA, malignant transformation and adverse effects of mTORi. RESULTS: In total, 120 patients with TSC visited our facility, including 24 patients with SEGA. Surgical resection was significantly more frequent in the Pre-group (6 of 7 patients, 86 %) than in the Post-group (2 of 17 patients, 12 %; p = 0.001). Acute hydrocephalus was seen in 1 patient (4 %), and no patients showed malignant transformation of SEGA. The group treated using mTORi showed significantly smaller SEGA compared with the group treated under a wait-and-see policy (p = 0.012). Adverse effects of pharmacotherapy were identified in seven (64 %; 6 oral ulcers, 1 irregular menstruation) of the 11 patients receiving mTORi. CONCLUSIONS: The Post-group underwent surgery significantly less often than the Pre-group. Since the treatment option to use mTORi in the treatment of SEGA in TSC became available, opportunities for surgical resection have decreased in our facility.

Significance and Priority of Surgical Resection as Therapeutic Strategy Based on Clinical Characteristics of Brain Metastases from Renal Cell Carcinoma.

OBJECTIVE: To clarify a rational surgical priority, clinical characteristics were compared between brain metastases (BM) from renal cell carcinoma (RCC) and other cancers. METHODS: We reviewed 425 consecutive patients with BM who underwent treatments including surgery between January 2014 and December 2022. Primary cancers included lung (n = 220), breast (n = 46), digestive (n = 65), RCC (n = 25), and others (n = 69). Tumor volume (T), edema volume (E), and edema volume/tumor volume ratio (E/T ratio) were compared between RCC and other primary cancers. Cutoff T values for identifying both symptomatic tumors and tumors suitable for surgery were determined by receiver operating characteristic curves. Factors including E/T ratio, age, Karnofsky Performance Scale score, and tumor characteristics were statistically analyzed. RESULTS: Cutoff values of T and E to determine surgical suitability were 4.973 cm3 (sensitivity, 0.848; specificity, 0.74) and 23.088 cm3 (sensitivity, 0.894; specificity, 0.623), respectively. E/T ratio was significantly higher for RCC than for other cancers (P < 0.01). These results remained consistent after propensity score matching. RCC tended to show a significantly lower frequency of posterior fossa tumor (16%, P < 0.01) and higher rates of single lesions (72%, P = 0.03) and intratumoral hemorrhage (24%, P = 0.02). Subgroup analysis limited to surgical cases showed that E was consistent across tumors, T tended to be smaller, and E/T ratio was significantly higher in RCC. CONCLUSIONS: Generally, symptomatic BM were indicated for surgery. BM from RCC were characteristically single, low-volume lesions with expanding edema and intratumoral hemorrhage, causing symptoms. These results suggest that surgery should be a high priority for BM from RCC.

Comparative analyses of immune cells and alpha-smooth muscle actin-positive cells under the immunological microenvironment between with and without dense fibrosis in primary central nervous system lymphoma.

Histopathologic examinations of primary central nervous system lymphoma (PCNSL) reveal concentric accumulation of lymphocytes in the perivascular area with fibrosis. However, the nature of this fibrosis in "stiff" PCNSL remains unclear. We have encountered some PCNSLs with hard masses as surgical findings. This study investigated the dense fibrous status and tumor microenvironment of PCNSLs with or without stiffness. We evaluated by silver-impregnation nine PCNSLs with stiffness and 26 PCNSLs without stiffness. Six of the nine stiff PCNSLs showed pathological features of prominent fibrosis characterized by aggregation of reticulin fibers, and collagen accumulations. Alpha-smooth muscle actin (αSMA)-positive spindle cells as a cancer-associated fibroblast, the populations of T lymphocytes, and macrophages were compared between fibrous and control PCNSLs. Fibrous PCNSLs included abundant αSMA-positive cells in both intra- and extra-tumor environments (5/6, 87% and 3/6, 50%, respectively). Conversely, only one out of the seven control PCNSL contained αSMA-positive cells in the intra-tumoral area. Furthermore, the presence of extra-tumoral αSMA-positive cells was associated with infiltration of T lymphocytes and macrophages. In conclusion, recognizing the presence of dense fibrosis in PCNSL can provide insights into the tumor microenvironment. These results may help stratify patients with PCNSL and improve immunotherapies for these patients.

Compartment syndrome associated with vascular avulsion caused by transradial access in neurointervention for unruptured intracranial aneurysm: illustrative case.

BACKGROUND: Transradial access (TRA) has a lower risk of access-site complications than transfemoral access but can cause major puncture-site complications, including acute compartment syndrome (ACS). OBSERVATIONS: The authors report a case of ACS associated with radial artery avulsion after coil embolization via TRA for an unruptured intracranial aneurysm. An 83-year-old woman underwent embolization via TRA for an unruptured basilar tip aneurysm. Following embolization, strong resistance was felt during removal of the guiding sheath due to vasospasm of the radial artery. One hour after neurointervention via TRA, the patient complained of severe pain in the right forearm, with motor and sensory disturbance of the first 3 fingers. The patient was diagnosed with ACS causing diffuse swelling and tenderness over the entire right forearm due to elevated intracompartmental pressure. The patient was successfully treated by decompressive fasciotomy of the forearm and carpal tunnel release for neurolysis of the median nerve. LESSONS: TRA operators should be aware that radial artery spasm and the brachioradial artery pose a risk of vascular avulsion and resultant ACS and warrant precautionary measures. Prompt diagnosis and treatment are essential because ACS can be treated without the sequelae of motor or sensory disturbance if properly addressed.

Risk factors for radial artery occlusion after neurointervention for unruptured intracranial aneurysm via transradial access.

PURPOSE: Neurointervention via transradial access (TRA) is less invasive than via transfemoral access. However, radial artery occlusion (RAO) may occur with TRA. The purpose of this study was to explore risk factors for RAO after coil embolization of unruptured intracranial aneurysms (UIAs) via TRA. METHODS: Forty-two consecutive patients who underwent coil embolization for UIAs via TRA between March 2021 and March 2022 and were available for angiographic evaluation 1 year after treatment were retrospectively reviewed. Multivariate logistic regression analysis was conducted to identify potential risk factors for RAO. RESULTS: Seventeen (40%) of the 42 patients showed RAO. Compared with the non-RAO group, radial artery size was significantly smaller (2.2 mm [interquartile range (IQR): 2.1, 2.4 mm] vs 2.6 mm [IQR: 2.5, 2.7 mm]; p = 0.001) and the incidence of radial artery spasm (RAS) was significantly higher in the RAO group. Multivariate analysis identified radial artery size (odds ratio [OR] 4.9 × 10-3, 95% confidence interval [CI] 6.4 × 10-5-0.38) and incidence of RAS (OR 14.8, 95%CI 2.1-105) as significant independent predictors of subsequent RAO. Based on receiver operating characteristic (ROC) curve analysis, the optimal cutoff for radial artery size was 2.5 mm (sensitivity, 82.4%; specificity, 76.0%; area under the ROC curve, 0.80 [95%CI 0.66-0.95]). CONCLUSION: Radial artery size and RAS represent reliable parameters for predicting RAO 1 year after coil embolization for UIA via TRA. Prophylaxis against RAS and limiting neurointervention via TRA to patients with radial artery larger than 2.5 mm in diameter may reduce the risk of postoperative RAO.

Therapeutic efficacy and complications of radial versus femoral access in endovascular treatment of unruptured intracranial aneurysms.

PURPOSE: The transradial approach (TRA) in neuroendovascular treatment is known to have a lower risk of complications than the transfemoral approach (TFA). However, little research has focused on assessments of efficacy and risk of complications in the treatment of intracranial aneurysms. This study aimed to compare the efficacy and complications of TRA and TFA in coil embolization of unruptured intracranial aneurysms (UIAs) at our institution. METHODS: Consecutive patients who underwent endovascular surgery via TRA or TFA at a single institution from 1 April 2019, to 28 February 2022, were retrospectively analyzed. Patients were classified into TRA and TFA groups and assessed using propensity-adjusted analysis for outcomes including fluoroscopy time, volume embolization ratio (VER), and complications. RESULTS: A total of 163 consecutive UIAs were treated with coil embolization during the 35-months study period. The incidence of minor access site complications (ASCs) was significantly higher with TFA (20%, 25/126) than with TRA (2.7%, 1/37; p = 0.01). Propensity-adjusted analysis (matched for age, sex, aneurysm volume, embolization technique, and sheath size) revealed that TRA was associated with a lower risk of minor ASCs (odds ratio, 0.085; 95% confidence interval 0.0094-0.78; p = 0.029). However, TRA did not differ significantly from TFA with respect to fluoroscopy time, VER, major ASCs, and non-ASCs. CONCLUSIONS: Coil embolization for UIAs via TRA can reduce risk of minor ASCs without increasing the risk of non-ASCs compared with conventional TFA, and can achieve comparable results in term of efficacy and fluoroscopy time.

Predicting difficult transradial approach guiding into left internal carotid artery on unruptured intracranial aneurysms.

Background: The transradial approach (TRA) is less invasive than the transfemoral approach (TFA), but the higher conversion rate represents a drawback. Among target vessels, the left internal carotid artery (ICA) is particularly difficult to deliver the guiding catheter to through TRA. The purpose of this study was thus to explore anatomical and clinical features objectively predictive of the difficulty of delivering a guiding catheter into the left ICA via TRA. Methods: Among 78 consecutive patients who underwent coil embolization for unruptured intracranial aneurysms through TRA in a single institution between March 1, 2021, and August 31, 2022, all 29 patients (37%) who underwent delivery of the guiding catheter into the left ICA were retrospectively analyzed. Clinical and anatomical features were analyzed to assess correlations with difficulty in guiding the catheter into the left ICA. Results: Of the 29 aneurysms requiring guidance of a catheter into the left ICA, 9 aneurysms (31%) required conversion from TRA to TFA. More acute innominate-left common carotid artery (CCA) angle (P < 0.001) and older age (P = 0.015) were associated with a higher conversion rate to TFA. Receiver operating characteristic analysis revealed that optimal cutoff values for the innominate-left CCA angle and age to distinguish between nonconversion and conversion to TFA were 16° (area under the curve [AUC], 0.93; 95% confidence interval [CI], 0.83-1.00) and 74 years (AUC, 0.79; 95% CI, 0.61-0.96), respectively. Conclusion: A more acute innominate-left CCA angle and older age appear associated with difficulty delivering the guiding catheter into the left ICA for neurointervention through TRA.

Feasibility of Mechanical Thrombectomy for Acute Ischemic Stroke Patients Aged 90 Years or Older Compared to Younger Patients.

Mechanical thrombectomy (MT) is a proven treatment for acute ischemic stroke (AIS). However, the efficacy of this treatment is uncertain for very elderly patients. This study aimed to investigate the safety and effectiveness of MT in 90 years or older patients compared with younger patients. We retrospectively reviewed AIS patients treated with MT between October 2018 and June 2020 in our institution. Patients were divided into two groups: aged ≥90 and <90 years. We compared the following factors: functional outcome at discharge, in-hospital death, successful recanalization, and complications. Multivariate logistic regression analysis for the good functional outcome was performed. In consideration of pre-stroke basic activities of very elderly patients, we defined the good functional outcome as modified Rankin Scale (mRS) 0-3. In all, 66 patients were included, and 19 patients (28%) were ≥90 years old. Pre-stoke mRS was higher in ≥90-year-old patients (p = 0.01). In ≥90-year-old patients, we achieved successful recanalization in 17 patients (90%), and only one patient experienced hemorrhagic complication related with the procedure. The good functional outcome (mRS: 0-3) at discharge were six patients (32%) in ≥90 years old versus 19 patients (40%) in <90 years old (p = 0.6). Three patients died in hospital in each group (16% versus 6%) (p = 0.3). Only the stroke severity was negatively related with the good functional outcome in a multivariate analysis. In conclusion, for ≥90-year-old patients compared with younger patients, MT is an equally feasible therapy. Patients should not be excluded from MT based on age alone.