Surgical Outcomes of Low-Flow Bypass Surgery in Intracranial Atherosclerotic Steno-Occlusive Diseases.

BACKGROUND AND OBJECTIVES: The role of bypass surgery in intracranial atherosclerotic steno-occlusive diseases (ICADs) remains controversial. We aimed to analyze the surgical outcomes of bypass surgery in patients with the ICADs in a single tertiary institution. METHODS: Among 1018 cases of low-flow bypass surgery between 2003 and 2022, 215 patients with the ICAD refractory to medical treatment were finally enrolled in this study. Clinical and radiological outcomes were retrospectively evaluated, with survival analyses. RESULTS: All strokes, cerebral infarctions, and intracranial hemorrhages occurred in 12.1% (n = 26), 9.8% (n = 21), and 2.3% (n = 5), respectively, during the clinical follow-up of 54.6 ± 47.6 months (range, 0.6-237.8 months). Among all stroke events, 84.6% (n = 22) occurred within 30 postoperative days. The 2-year and 5-year cumulative risks of all strokes were 12.1% each. The mean modified Rankin Scale scores were 1.6 ± 1.1 (range, 0-5) preoperatively and 0.8 ± 1.2 (range, 0-6) at last (P < .01). The patency of direct bypass was 99.1% (n = 213) just before discharge and 96.3% (n = 184 of 191 patients with available tests) at the last angiographic follow-up of 27.0 ± 27.3 months (range, 2.3-97.3 months). All the patients with available data (n = 190) showed hemodynamic improvement on acetazolamide-challenged single-photon emission computed tomography with 99mTc-hexamethylpropyleneamine oxime during the follow-up of 38.6 ± 36.7 months (range, 2.3-158.6 months). CONCLUSION: Low-flow bypass surgery showed acceptable treatment outcomes in the prevention of recurrent stroke.

Natural course of hemodynamically stable hemispheres contralateral to operated hemispheres in adult patients with ischemic moyamoya diseases.

The necessity of bilateral bypass in adult moyamoya disease (MMD) remains unclear despite its recommendation for pediatric and hemorrhagic cases. We aimed to investigate the natural course of hemodynamically stable unoperated hemispheres after bypass surgery for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD. Among 288 patients, the mean age at the first operation of the unstable hemispheres was 40.8 ± 12.2 years. The mean follow-up period was 62.9 ± 46.5 months. 45 patients (15.6%) experienced stroke events in the unoperated hemisphere, consisting of hemorrhagic stroke in 8 (2.8%) and ischemic stroke in 37 (12.8%), including progressive transient ischemic attack in 25 (8.7%) and infarction in 12 (4.2%). Among them, 39 patients (13.5%) underwent bypass surgery. The annual risk of total stroke is 3.0%/patient-year, with 2.5% for ischemic stroke and 0.5% for hemorrhagic stroke. The 5- and 10-year cumulative risks of ischemic stroke were 13.4% and 18.3%, respectively, and those of hemorrhagic stroke were each 3.2%. The natural course of hemodynamically stable hemispheres contralateral to the operated ones appeared fairly good. Additional bypass surgery on the unoperated hemispheres should be considered for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD during the follow-up.

Surgical Thrombectomy for Extensive Cerebral Venous Sinus Thrombosis after COVID-19 Vaccination : A Novel Surgical Technique and Literature Review.

Surgical treatment of refractory and extensive cerebral venous sinus thrombosis (CVST) has limited applications. Here, we describe an open, direct sinus thrombectomy in the early phase of extensive CVST. A 49-year-old man with extensive CVST that occurred after the coronavirus disease 2019 (COVID-19) vaccination and affected the drainage of the Labbé vein presented with clinical deterioration and left temporal hemorrhagic infarction. Since the patient had extensive CVST, we determined that systemic anticoagulation and endovascular treatment were not suitable treatment options. Therefore, we decided on an emergency surgical treatment and performed direct surgical thrombectomy. We followed extended suboccipital approach and made multiple incisions on the sinuses, exposing the posterior superior sagittal sinus to the transverse sigmoid junction. Consequently, the clinical condition of the patient dramatically improved, resulting in a favorable outcome with a modified Rankin Scale score of 0. Performing emergency open surgical thrombectomy was a technically feasible treatment option that recanalized obstructed sinuses. Importantly, the patient recovered with a good clinical outcome. Early maximal surgical thrombectomy is an effective and lifesaving method to treat extensive CVST with hemorrhagic infarction.

Clinical significance of "periventricular collateral enhancement sign" in symptomatic moyamoya disease: A vessel wall imaging study.

BACKGROUND: Periventricular collaterals are associated with high risk of hemorrhagic stroke in adult moyamoya disease (MMD). However, the clinical significance of the periventricular collateral enhancement sign (PCES), which indicates wall enhancement of periventricular collaterals on contrast-enhanced vessel wall imaging (VWI), has yet to be determined. METHODS: Thirty-seven patients with MMD with acute neurological symptoms were consecutively recruited. Periventricular collaterals including lenticulostriatal artery, thalamic artery, and choroidal artery collaterals were evaluated on digital subtraction angiography, and then PCES was detected on pre- and postcontrast VWI. First, the association between PCES and hemorrhagic presentation was evaluated using multivariate analyses. Second, two raters investigated the culprit vessels responsible for bleeding in hemorrhagic MMD using the Cohen kappa statistic. RESULTS: Fifteen sites of PCES on postcontrast VWI were observed in 15 patients. Multivariate analysis revealed that hemorrhagic presentation was the only independent factor for PCES (OR = 37.3, 95%CI = 3.9-113, p =.002). In patients with hemorrhagic presentation (n = 20), the identification rate of the ruptured vessel was 80% by rater 1, with excellent agreement. (inter-rater, κ = 0.86, 95%CI = 0.59-1.00; intra-rater, κ = 0.83, 95%CI = 0.50-1.00). Choroidal (50%) and thalamic artery collaterals (15%) were the most common and the second most common types of culprit vessels. Inter-rater and intra-rater reliabilities for the classification of culprit vessels were also excellent (intra-rater, κ = 0.86, 95%CI = 0.67-1.00; inter-rater, κ = 0.93, 95%CI = 0.79-1). CONCLUSION: Acute hemorrhagic stroke in MMD is independently associated with PCES on postcontrast VWI. PCES can help to detect the culprit vessels that are responsible for hemorrhage in patients with MMD.

Can Trigeminal Schwannoma-Related Symptoms be Controlled With Gamma Knife Radiosurgery?

OBJECTIVE: The effectiveness of gamma knife radiosurgery (GKRS) for the management of trigeminal schwannomas (TS) has been established. Although GKRS has been shown to inhibit tumor growth, the effect of GKRS on the symptoms caused by TS has not been sufficiently studied. In this study, symptomatic changes following GKRS for the management of symptomatic TS were investigated using long-term follow-up results. METHODS: A retrospective analysis was performed on 32 patients with TS who underwent GKRS between May 1994 and December 2016. Clinical charts, radiographic results, and surgical records were reviewed. To evaluate whether symptoms improved after GKRS, patient demographics, GKRS profile, radiological tumor size change, and tumor location were analyzed. RESULTS: Tumor control after GKRS for symptomatic TS was 87%. The improvement rates for facial pain at 6, 12, and 24 months after GKRS were 46%, 72%, and 86%, respectively. For the same time intervals, facial hypesthesia improved by 12%, 46%, and 52%, respectively. Of the patients with diplopia, 17% had improved symptoms 12 months after GKRS, and 50% of the patients improved after 24 months. CONCLUSIONS: GKRS can be an effective treatment modality for TS tumor control and shows favorable results in improving TS-related symptom, especially facial pain.