Akitsugu Kawashima

BACKGROUND: Although intraluminal shunt insertion during carotid endarterectomy (CEA) is widely used to maintain cerebral perfusion, distal intimal injury of the internal carotid artery (ICA) can occur as a rare yet consequential complication. OBSERVATIONS: An 82-year-old man with an elongated styloid process who underwent CEA for left ICA stenosis at the C2 vertebral level developed a new progressive high-grade stenosis immediately distal to the endarterectomy site, likely associated with shunt manipulation. Preoperative images demonstrated that the distal ICA segment at the C1 vertebral level was positioned between the styloid process anterolaterally and the transverse process of C1 posteromedially, in closer proximity to these osseous structures than on the right side. The dissected segment corresponded to the region of closest proximity between the ICA and the transverse process of C1. The patient underwent carotid artery stent placement for the distal dissected stenosis without neurological sequelae. LESSONS: This case suggests that an Eagle syndrome–like osseous-vascular configuration may predispose the artery to shunt-related injury during CEA. Meticulous preoperative assessment of the relationship between the ICA and both the transverse process of C1 and the styloid process may help mitigate the risk of distal ICA dissection in high cervical lesions with an elongated styloid process. https://thejns.org/doi/10.3171/CASE26320

Bilateral vertebral artery dissection aneurysm (VADA) is a rare condition that leads to severe stroke. However, the surgical strategy for its treatment is controversial because the pathology is very complicated and varies in each case.

OBJECTIVE: Patients with pediatric moyamoya disease (PMMD) showing recurrent symptoms or decreased cerebral blood flow after initial revascularization therapy may require additional revascularization to improve their clinical condition. The authors evaluated the clinical and hemodynamic benefits of an occipital artery (OA)–middle cerebral artery (MCA) bypass for patients with PMMD who have undergone an initial revascularization procedure. METHODS: The authors retrospectively identified 9 patients with PMMD who had undergone OA-MCA bypass between March 2013 and December 2017, and who had received a previous superficial temporal artery–MCA bypass. The following clinical data were collected: initial revascularization procedure, symptoms (presence or recurrence), pre- and postoperative cerebral blood flow and cerebrovascular reactivity (CVR) changes, posterior cerebral artery (PCA) stenosis, PCA-related and nonrelated symptoms, and latest follow-up. RESULTS: Preoperatively, all patients (n = 9) suffered non–PCA-related recurrent symptoms, and 4 had PCA-related symptoms. At 1-year follow-up, all patients with PCA-related symptoms showed complete recovery. Additionally, 8 (89%) patients with non-PCA symptoms experienced improvement. Only 1 (11%) patient showed no improvement after the surgical procedure. The mean pre- and postoperative CVR values of the MCA territory were 14.8% and 31.3%, respectively, whereas the respective mean CVR values of the PCA territory were 22.8% and 40.0%. CONCLUSIONS: The OA-MCA bypass is an effective rescue therapy to improve the clinical condition and hemodynamic changes caused by PMMD in patients who experience recurrent symptoms after initial revascularization.

Introduction: Moyamoya disease (MMD) is a rare cerebrovascular disease associated with cerebral infarction or hemorrhage. Hyperperfusion is the most significant complication of direct bypass surgery. Previous research has shown that an increase in cerebral blood flow (CBF) is strongly related to symptomatic hyperperfusion and highlighted the importance of postoperative assessment of CBF. Objective: The principal aims of this study were to quantitatively analyze the relationship between intraoperative graft flow and increase in CBF and to evaluate the effectiveness of intraoperative graft flow measurement during bypass surgery for patients with MMD. Methods: This study included 91 surgeries in 67 consecutive adult patients with MMD who underwent direct revascularization surgery at our institution between November 2013 and September 2018. Intraoperative graft flow of the branches and main trunk was measured in all patients, after anastomosis had been established. Postoperative CBF measurements were performed under sedation, immediately after surgery. Radiological hyperperfusion was defined as focal high uptake, as determined by CBF imaging immediately after surgery. Patients were divided into two groups (radiological hyperperfusion and nonradiological hyperperfusion groups), and the relationship between intraoperative graft flow and radiological hyperperfusion was analyzed. Results: Significant differences were observed between the radiological hyperperfusion and nonradiological hyperperfusion groups in terms of intraoperative graft flow of both the branch (median 72 vs. 42 mL/min, respectively; p < 0.01) and main trunk (median 113 vs. 68 mL/min, respectively; p < 0.01). A receiver-operating characteristic analysis was performed to test the utility of intraoperative flow as a quantitative measure. We set the cutoff values for the intraoperative branch and main trunk flow at 57 mL/min (sensitivity: 0.707, specificity: 0.702; area under the curve [AUC]: 0.773; 95% confidence interval [CI]: 0.675–0.871) and 84 mL/min (sensitivity: 0.667, specificity: 0.771; AUC: 0.78; 95% CI: 0.685–0.875), respectively. Conclusions: Measuring intraoperative graft flow during bypass surgery may be an effective means of predicting hyperperfusion and could serve to facilitate early therapeutic intervention such as strict blood pressure control.

Background: Superior cerebellar artery (SCA) aneurysms are rare. Current treatments include: direct clipping, trapping ± bypass, and endovascular methods (coiling, stenting, or flow diversion). Due to specific characteristics (wide base, location, and shape), a major challenge while dealing with SCA aneurysms is to preserve the flow of the parent artery and perforators. This video demonstrates a revascularization procedure, and clip reconstruction of a large unruptured basilar artery (BA)/SCA aneurysm performed through the subtemporal approach. Case Description: A 60-year-old woman presented with dizziness and headaches. Computed tomography angiography (CTA) and digital subtraction angiography showed a right unruptured large BA/SCA aneurysm. After multidisciplinary discussion, and considering gender, age, risk factors of the patient. Endovascular treatment was considered with a high risk of ischemic complications. Therefore, the patient was consented for a superficial temporal artery (STA)-SCA bypass through subtemporal approach followed by direct clipping/ trapping of the aneurysm. Postoperative CTA showed occlusion of the aneurysm and patency of the parent vessels. Postoperatively, the patient experienced immediate transient left mild monoparesis and right IV nerve palsy, which recovered completely at 6-months follow-up. Results: Surgical treatment of SCA aneurysms is decreasing due to the existence of endovascular therapies such as stents and flow diverters. However, some cases may necessitate surgical treatment and revascularization procedures to maintain the blood flow of the parent artery and to treat the previous lesion. Conclusion: The STA-SCA bypass through the subtemporal approach is a feasible option to maintain the blood flow of the parent artery in cases of SCA requiring surgical treatment and trapping/direct clipping of the aneurysm.

もやもや病治療の研究の進歩は著しく, 2015年には診断基準が改定された. 直接血行再建術は治療の中心であり, 虚血発症例だけでなく, 出血発症例に対しても有効性が証明された. 後方循環系への出血例は再出血しやすく, 直接血行再建術による再発予防効果は顕著であった. 未解決問題も数多く残っている. もやもや病と動脈硬化性疾患の鑑別はときに困難であり, 急速進行例への治療には難渋している. 直接血行再建術術後, さまざまな画像変化が報告されているが, 過灌流症候群を中心とした術後合併症との関係は明らかでない. もやもや病症例の高次脳機能障害の正確な評価, 無症候性例の自然歴の解明から, 血行再建術の新たな適応の構築が期待される.