Validity about Diameter of Guiding Catheter for Posterior Circulation Derived by MRA Study.

Objective: The development of large-bore aspiration catheters (ACs) has advanced the treatment of mechanical thrombectomy (MT) and their use requires larger guiding catheters (GCs). However, due to the small vessel diameter of the vertebral artery (VA), it can be difficult to cannulate large-bore GC to the VA. This study aims to determine the percentage of VAs that are amenable to GC placement based on the use of a large-bore AC and to clarify the diameters of VAs in the general population using neck MRA. Methods: Left and right VA diameters were measured in 1394 consecutive adult patients who underwent neck MRA at our hospital between April 2020 and June 2021. Sex and left/right differences in the VA diameters, as well as the conformity ratios of GCs (6, 7, and 8 French) to right and left VAs, were examined. Results: The patients ranged in age from 18 to 98 years (mean 70.8 ± 13.5 years), with 770 (55.2%) males. The left and right VA mean diameters were 2.82 ± 0.75 mm (range 0-5.1 mm) and 2.65 ± 0.75 mm (range 0-5.3 mm), respectively. The conformity ratios of 6, 7, and 8 French GC to left and right VAs were 85.3% and 79.9%, 74.9% and 68.4%, and 60.9% and 53.7%, respectively. Conclusion: When performing MT for the posterior circulation system, a large-bore AC of 0.060 inches or larger is usually required, and GC placement of 7-French or larger is necessary. The results of this study showed that 7-French GC placement is achievable in approximately 70% of these cases.

Sagittal splitting of the temporalis muscle for encephalo-myo-synangiosis to prevent ischemic complications due to a swollen temporalis muscle without inhibiting collateral developments in patients with moyamoya disease.

OBJECTIVEEncephalo-myo-synangiosis (EMS) is an effective revascularization procedure for the treatment of moyamoya disease (MMD). However, the temporalis muscle used for EMS sometimes swells and causes ischemic complications by compressing the underlying brain. This study aimed to elucidate the effect of sagittal splitting (SS) of the muscle for prevention of ischemic complications and its impact on the postoperative development of collateral vessels.METHODSIn this historical case-control study, we analyzed 60 hemispheres in adult patients with MMD who underwent EMS using the temporalis muscle from December 1998 to November 2017. The muscle was divided anteroposteriorly by coronal splitting, and the anterior, posterior, or both parts of the muscle were used for EMS in 17, 4, and 39 hemispheres, respectively. In cases performed after 2006, the muscle was halved by SS, and the medial half was used for EMS to reduce the muscle volume (n = 47). The degree of postoperative muscle swelling was evaluated by measuring the maximum thickness of the muscle on CT scans obtained 3 to 7 days after surgery. The collateral developments of the anterior deep temporal artery (aDTA), posterior deep temporal artery (pDTA), and middle temporal artery (MTA) were assessed using digital subtraction angiography and MR angiography performed 6 months or more after surgery.RESULTSSS significantly reduced the temporalis muscle thickness from 12.1 ± 5.0 mm to 7.1 ± 3.0 mm (p < 0.01). Neurological deterioration due to the swollen temporalis muscle developed in 4 of the 13 hemispheres without SS (cerebral infarction in 1, reversible neurological deficit in 2, and convulsion in 1) but in none with SS. There were no significant differences in the postoperative collateral developments of the aDTA, pDTA, and MTA between hemispheres with and without SS. The MTA more frequently developed in hemispheres with EMS in which the posterior part of the muscle was used (30/37) than those in which this part was not used (4/16) (p < 0.01).CONCLUSIONSSS of the temporalis muscle might prevent neurological deterioration caused by the swollen temporalis muscle by reducing its volume without inhibiting the development of the collateral vessels.

Postoperative Cerebral Ischemia Due to Hypotension in Moyamoya Patient with Autonomic Dysfunction.

BACKGROUND: Hypotension is a significant risk factor for the development of ischemic complication following revascularization surgery for moyamoya disease (MMD). However, it is currently unknown whether autonomic dysfunction also plays a role. CASE DESCRIPTION: Here we report a case of MMD in which hypotension due to autonomic dysfunction caused postoperative cerebral ischemia. A 30-year-old female patient with MMD had a history of transient right hemiparesis following laughter. Single-photon emission computed tomography showed impaired cerebral blood flow (CBF) in both cerebral hemispheres, so she underwent revascularization surgery in her left cerebral hemisphere. She awoke from anesthesia uneventfully; however, 1 hour after the surgery her blood pressure suddenly dropped to 90/40 mm Hg and she became comatose. A perfusion computed tomography scan demonstrated a widespread reduction in CBF in the left hemisphere. Bezold-Jarisch reflex was thought to be the cause of the hypotension. Following treatment with a vasopressor agent, her BP increased and her consciousness rapidly recovered. The reduced CBF had almost completely recovered the next day. Head-up tilt test conducted 2 weeks after surgery demonstrated latent vasopressor-type autonomic dysfunction, which was possibly another cause of the hypotension. She was discharged from the hospital, and the laughter-induced hemiparesis gradually resolved. CONCLUSION: Situational neurologic deterioration in patients with MMD suggests latent autonomic dysfunction, which may be a risk factor for postoperative ischemic complications.

Cortical Venous Redness Represents Tissue Circulation Status in Patients With Moyamoya Disease.

BACKGROUND AND PURPOSE: Venous oxygen saturation (SO2) is measured in medical fields to assess tissue circulation insufficiency. This study aimed to elucidate the use of a cortical venous redness measurement to evaluate hemodynamic changes during revascularization surgery for patients with moyamoya disease. METHODS: In this retrospective case-series analysis, we first quantitatively measured and correlated SO2 and R intensity of 24-bit color digital red-green-blue pictures of blood samples from 3 volunteers. Subsequently, based on intraoperative digital pictures of 29 patients with moyamoya disease, we measured the R intensities of a cortical vein near the anastomosis site before and after anastomosis. Cerebral blood flow (CBF) at the site was measured using a single-photon emission computed tomography before and 1 to 3 days after surgery. Venous R intensity and CBF were measured twice by 4 raters, and their correlations were examined using generalized linear mixed effect model and linear regression analysis. RESULTS: A strong linear correlation was found between blood R intensity and its SO2 (coefficients, 0.522; 95% confidence interval, 0.364-0.680, using generalized linear mixed effect model). Venous R intensity before the anastomosis was not correlated with preoperative CBF (coefficients, 0.000352; 95% confidence interval, -0.000369 to 0.00107, by generalized linear mixed effect); however, the increases in venous R intensity after anastomosis were correlated with postoperative increases in CBF (R2, 0.367; 95% confidence interval, 0.116-0.618 to 0.548; 95% confidence interval, 0.331-0.764, by linear regression analysis). CONCLUSIONS: Cortical venous redness represented impaired CBF and could be a useful parameter for assessing hemodynamic changes during revascularization surgery.

Subcortical Low-Intensity Lesions on Fluid-Attenuated Inversion Recovery Images After Revascularization Surgery for Moyamoya Disease.

OBJECTIVE: Although uncommon, subcortical low-intensity (SCLI) changes on fluid-attenuated inversion recovery images are observed in various diseases, including cerebral ischemia. Here, we aimed to clarify the incidence and clinical implications of SCLI changes after revascularization surgery for moyamoya disease, focusing on the correlation with postoperative transient neurologic events (TNEs). METHODS: In this retrospective case series analysis, we included 10 hemispheres from 9 adults with moyamoya disease who underwent revascularization surgery. Subcortical signal intensity at the 5 gyri around the anastomosis point was quantitatively measured at 1 week and 3 months postoperatively. Changes in cerebral blood flow (CBF) were assessed using single-photon emission computed tomography. RESULTS: Images taken 1 week after surgery showed widespread SCLI changes below the operative fields in all 10 cases, but these changes normalized by 3 months. In addition, the changes in signal intensity at anastomoses negatively correlated with the changes in CBF (R2 = 0.36; P = 0.039). Postoperative TNEs occurred in 6 cases (60%) but were resolved within 17 days after surgery. Postoperative CBF increased in 9 of the 10 cases, with a median of 23%; however, these increases were not associated with the development of TNEs. The SCLI changes at the anastomosis points did not differ by the experience of TNEs. CONCLUSIONS: Early after surgery, SCLI changes are common findings below the operative fields but negatively correlate with increases in CBF. Although no significant association was found between TNEs and the SCLI changes, the synchronized development of these phenomena may suggest a common underlying pathogenesis.

Primary diffuse leptomeningeal gliomatosis followed with serial magnetic resonance images.

We report a case of primary diffuse leptomeningeal gliomatosis (PDLG) followed up with serial magnetic resonance images (MRI). A 45-year-old man manifested with bilateral abducens nerve palsy and meningisms. Repeated MRI revealed diffuse leptomeningeal enhancement throughout the central nervous system without intra-axial mass accompanied with the dilatation of ventricles and focally enlarged cerebral sulci. Brain biopsies showed a leptomeningeal gliomatosis. The MRI findings described here would contribute to the diagnosis of PDLG among other common diseases diffusely spreading along the leptomeningeal structures.