Comparison of efficacy between clazosentan and fasudil hydrochloride-based management of vasospasm after subarachnoid hemorrhage focusing on older and WFNS grade V patients: a single-center experience in Japan.

Subarachnoid hemorrhage often leads to poor outcomes owing to vasospasm, even after successful aneurysm treatment. Clazosentan, an endothelin receptor inhibitor, has been proven to be an effective treatment for vasospasms in a Japanese randomized controlled trial. However, its efficacy in older patients (≥ 75 years old) and those with World Federation of Neurosurgical Societies (WFNS) grade V has not been demonstrated. We retrospectively evaluated the efficacy of clazosentan in older patients and those with WFNS grade V, using real-world data. Patients with subarachnoid hemorrhage treated before and after the introduction of clazosentan were retrospectively evaluated. The patients were categorized into two groups (clazosentan era versus pre-clazosentan era), in which vasospasm management and outcomes were compared. Vasospasms were managed with fasudil hydrochloride-based (pre-clazosentan era) or clazosentan-based treatment (clazosentan era). Seventy-eight patients were included in this study: the clazosentan era (n = 32) and pre-clazosentan era (n = 46). Overall, clazosentan significantly reduced clinical vasospasms (clazosentan era: 31.3% versus pre-clazosentan era: 60.9%, p = 0.01), delayed cerebral ischemia (DCI) (9.4% versus 39.1%, p = 0.004), and vasospasm-related morbidity and mortality (M/M) (3.1% versus 19.6%, p = 0.03). In subgroup analysis of older patients or those with WFNS grade V, no significant difference was observed in clinical outcomes, although both DCI and vasospasm-related M/M were lower in the clazosentan era. Clazosentan was more effective than fasudil-based management in preventing DCI and reducing vasospasm-related M/M. Clazosentan could be used safely in older patients and those with WFNS grade V, although clinical outcomes in these patients were comparable to those of conventional treatment.

Horizontal stent deployment via extracranial-intracranial bypass in coil embolization of basilar apex aneurysms: technical report.

BACKGROUND: The endovascular treatment of large, wide-necked basilar apex aneurysms (BAAs) remains challenging. Although horizontal stent deployment across both P1 segments of the posterior cerebral arteries (PCAs) would be an optimal strategy in coil embolization of wide-necked BAAs, this is only feasible in cases with anatomically favorable access. In rare circumstances, large-diameter conduits of extracranial-intracranial (EC-IC) bypass can also provide a good access route for endovascular treatment of complex intracranial aneurysms. METHODS: We describe the technique of accessing the PCA via EC-IC bypass grafts and deploying a stent horizontally across the neck of BAA and its coil embolization. We provide a detailed technical review and describe some pitfalls of the procedure. RESULTS: Two patients underwent EC-IC bypass surgery prior to the treatment of a large, wide-necked BAA. The radial artery and saphenous vein were used as grafts, respectively. To facilitate coil embolization for a large BAA, a PCA-to-PCA horizontal stent was deployed via the bypass graft. Trans-cell and jailing techniques were used, respectively. Both aneurysms were completely occluded, and the patients were discharged without any neurological deficit. CONCLUSION: Horizontal stent deployment via EC-IC bypass grafts can be performed safely, providing proper closure of the aneurysmal neck and apposition to both PCAs, facilitating complete coil embolization.

A case of idiopathic extracranial carotid artery pseudoaneurysm with a rare clinical course and pathological features.

Extracranial carotid artery aneurysms (ECAAs) are rare, with the etiology mainly classified as degeneration or dissection. Pseudoaneurysms in the region are even rarer and are seen following trauma, iatrogenic injury, or infection. We report a case of extracranial carotid artery pseudoaneurysm (pseudo-ECAA) with a rare clinical course and pathological features. A 58-year-old man presented with swelling and purpura on the left side of his neck after sneezing. Radiological examinations suggested a ruptured left common carotid artery aneurysm. The operative findings were consistent with a pseudoaneurysm. Pathological examination revealed disarrangement and degeneration of smooth muscle fibers in the media, in addition to scattered foci of mucoid accumulation and irregular-shaped cavitation in the medial extracellular matrix, raising the possibility of an intrinsic dysfunction of the vascular wall in the pathological process of pseudoaneurysm formation.

Maximum Nidus Depth as a Risk Factor of Surgical Morbidity in Eloquent Brain Arteriovenous Malformations.

BACKGROUND: Eloquent location of a brain arteriovenous malformation (BAVM) is known to increase the surgical risk. Surgical removal of such BAVMs is challenging. Useful indicators for the safe removal of eloquent BAVMs are needed. The aim of this study was to determine the surgical risk factors for these challenging entities. METHODS: The authors retrospectively reviewed 29 motor and/or sensory BAVM patients who underwent surgeries. The risk factors for surgical morbidity were analyzed. As a new risk factor, maximum nidus depth, was evaluated. RESULTS: Complete obliteration was achieved in 28 patients (96.6%). Postoperative transient and permanent neurological deteriorations were seen in nine patients (31.0%) and five patients (17.2%), respectively. In univariate analysis, maximum nidus depth (p = 0.0204) and asymptomatic onset (p = 0.0229) were significantly correlated with the total morbidity. In multivariate analysis, only maximum nidus depth was significantly correlated with total morbidity (p = 0.0357; odds ratio, 2.78598; 95% confidence interval, 0.8866-8.7535). The cut-off value for the maximum nidus depth was 36 mm for total morbidity (area under the curve [AUC], 0.7428) and 41 mm for permanent morbidity (AUC, 0.8833). The cutoff value of the maximum nidus size was 30 mm for total morbidity (AUC, 0.5785) and 30 mm for permanent morbidity (AUC, 0.7625). AUC was higher for the maximum nidus depth than it was for the maximum nidus size. CONCLUSIONS: Maximum nidus depth was significantly associated with surgical morbidity of eloquent BAVMs. The maximum nidus depth is a novel and a simpler indicator of the risk of surgical morbidity.

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.

Infantile Aspergillus fumigatus ventriculitis successfully treated with monitoring of plasma and cerebrospinal fluid voriconazole concentration level.

Aspergillosis is a rare fungal infection in newborns, and its morbidity and mortality are high. Voriconazole (VRCZ) is the first-line antifungal agent for invasive Aspergillus infection, but little data is available about its pharmacokinetics in infants. We report a case of a premature infant who developed ventriculitis due to Aspergillus fumigatus and received combination antifungal therapy including VRCZ. ß-D glucan and Aspergillus antigen index were elevated in the cerebrospinal fluid (CSF). We titrated the dose of VRCZ by monitoring plasma and CSF concentrations. The CSF to plasma concentration ratio of VRCZ ranged from 0.47 to 1.36 (median 0.71). While VRCZ adequately penetrates the blood-brain barrier, its concentration is highly variable in infants.

Do Direct Bypasses Really Resolve Capillary Vessels in Moyamoya Disease? Delayed Hemorrhage Potentially Relevant to Direct Bypasses: A Pathological Investigation.

OBJECTIVE: Moyamoya disease is a chronic but progressive obliterative cerebrovascular disease of bilateral internal carotid arteries (ICAs) causing hemorrhagic or ischemic cerebral strokes. Surgical revascularization has the potential for resolving the capillary vessels, but the effect on the occlusive ICA and the moyamoya vessels after a direct bypass remains unclear. PATIENT: A 2-year-old girl with a history of repeated transient ischemic attacks and direct bypasses but demonstrating improvement and associated anomaly is reported. A year and a half later, after a bilateral revascularization, an intracerebral capsulized hematoma growth was identified, and it was removed surgically. Neovascularization including many microvessels similar to capillary telangiectasia were identified by pathological investigation despite the reduction of moyamoya vessels on the repeated angiograms after the revascularization surgeries. In the present case, proliferation of capillary vessels was clearly confirmed by direct bypasses. CONCLUSION: There is no doubt that direct bypasses prevent further ischemic stroke by improving cerebral blood flow. However, they may result in failure in reducing the load of moyamoya vessels, albeit decreasing the potential risk of hemorrhagic strokes.

Can Moyamoya Disease Susceptibility Gene Affect Extracranial Systemic Artery Stenosis?

Diseases associated with the RNF213 gene include moyamoya disease, with the p.R4810K (c.14429G>A, rs112735431) homozygous variant thought to be the most pathogenic and significantly associated with severe manifestation such as early onset or cerebral infarction at onset. We report a case of a unique Japanese pedigree associated with RNF213. A 53-year-old woman with no arteriosclerotic risk factors experienced coronary artery disease, followed by coronary artery bypass surgery. In 8 years, she suffered sudden abdominal pain. Her abdominal contrast computed tomography revealed stenosis of abdominal artery and superior mesenteric artery. Though her 2 children and uncle had a typical moyamoya disease with RNF213 p.R4810K heterozygous variant, she has had no clinical and radiological evidence of moyamoya disease. Due to a family history of moyamoya disease, a genetic investigation was performed and revealed RNF213 p.R4810K homozygous variant. A possible role of RNF213 influencing systemic artery stenosis can be further be understood from this rare case harboring the homozygous variant carrier.

[Advantages and Pitfalls of the Lateral Supraorbital Approach as Less Invasive Surgery for Unruptured Anterior Circulation Aneurysms].

The lateral supraorbital approach(LSOA)is widely accepted as a less invasive surgical technique compared with the conventional pterional approach(PA). However, only a few studies have reported less invasiveness associated with LSOA. To evaluate this issue, we retrospectively investigated the surgical outcomes in 133 patients who underwent LSOA and 28 patients who underwent PA for unruptured anterior circulation aneurysms. We analyzed operation time, postoperative symptoms and complications, and the length of postoperative hospitalization(in days)for each method. All aneurysms were successfully clipped regardless of the approach. The operation time was significantly shorter, the postoperative headache rate was lower, resumption of oral intake was more rapid, and length of hospitalization was shorter in the LSOA group. Statistical significance was not observed in the postoperative complication rates. Compared with conventional PA, LSOA was associated with less invasiveness and better patient satisfaction. LSOA is a safe and effective alternative to conventional PA, following optimal patient selection.

Genotype-Phenotype Correlation in Long-Term Cohort of Japanese Patients with Moyamoya Disease.

BACKGROUND: Homozygosity of this p.R4810K founder variant of RNF213moyamoya disease (MMD) susceptibility gene is known to influence the severity of the clinical disease phenotype at disease onset. However, the association between this genotype and long-term clinical manifestations has remained unclear. OBJECTIVES: The principal goal of this study was to investigate whether and how the p.R4810K variant of RNF213influences the long-term phenotype in Japanese patients with MMD. METHOD: This retrospective cohort study included 94 Japanese patients with MMD who underwent direct or combined bypass for revascularization with the p.R4810K genotype determined in our hospital. The following phenotypic parameters were analyzed at disease onset and over a long-term period: age and initial presentation at onset, recurrent stroke after initial revascularization, and final modified Rankin Scale. RESULTS: The p.R4810K genotype was significantly associated with the phenotype at onset, especially in younger patients. Over a median follow-up period of 100 months, recurrent stroke occurred in 6 out of 94 patients: none out of 5 patients with the homozygous variant, 5 out of 64 with the heterozygous variant, and 1 out of 25 in the wild-type group. There were no significant differences among the genotypes. In particular, recurrent cerebral hemorrhage occurred in 5 patients, all possessing the heterozygous variant. The log-rank test showed no difference between the genotypes in the stroke-free survival rate. Furthermore, the p.R4810K genotype was not associated with a poor functional condition. CONCLUSIONS: The p.R4810K founder variant of RNF213 affects the phenotype at disease onset. However, the optimal revascularization may be effective, regardless of the genotype, even for the homozygous variant, which has been thought to be the most pathogenic. This genotype may not strongly influence the long-term clinical manifestations or poor prognosis in MMD.

Efficacy of superficial temporal artery-middle cerebral artery double bypass in patients with hemorrhagic moyamoya disease: surgical effects for operated hemispheric sides.

The effects of superficial temporal artery to middle cerebral artery (STA-MCA) double bypass on recurrent hemorrhage in the operated hemisphere in hemorrhagic moyamoya disease (HMD) have not been clearly demonstrated. This study evaluated the effectiveness of STA-MCA double bypass in the prevention of further hemorrhagic or ischemic events in the operated hemispheric sides in comparison to the conservatively treated non-operated sides. We retrospectively analyzed 52 hemispheres of 36 patients with adult-onset HMD treated with STA-MCA double bypass. Twenty and 16 patients underwent unilateral (unilateral group) and bilateral (bilateral group) surgery, respectively. In addition, the perioperative and long-term outcomes of the 52 operated sides and 20 non-operated sides in the unilateral group were compared. All bypass surgeries were successful, but 21% of the operated sides showed hyperperfusion as estimated by our methods. Perioperative mortality and morbidity rate were 0% and 5.6%, respectively. Concerning long-term follow-up, the annual rebleeding rate (ARR) in the unilateral and bilateral group was 2.7% and 2.6%/person-year, respectively (p = 0.256). The ARR in the operated and non-operated sides was 1.1% and 1.8%/side-year, respectively (p = 0.163). Two of 20 non-operated sides suffered from ischemic infarction during the follow-up period, while none of the 52 operated sides experienced ischemic events (p < 0.05). Although the long-term rebleeding rate in the operated hemisphere tended to be lower after STA-MCA double bypass compared with that in the non-operated hemisphere, the difference was not statistically significant. In conclusion, while STA-MCA double bypass could not clearly prevent rebleeding, it can prevent further ischemic attacks in patients with HMD.

Correction to: Efficacy of superficial temporal artery-middle cerebral artery double bypass in patients with hemorrhagic moyamoya disease: surgical effects for operated hemispheric sides.

Table 2 of the original version of this article contained an added data. Correct Table 2 is presented here.

Clinical factors influencing the development of extracranial-intracranial bypass graft for steno-occlusive cerebrovascular disease.

OBJECTIVEEffectively retaining the patency of the extracranial-intracranial (ECIC) bypass is one of the most important factors in improving long-term results; however, the factors influencing bypass patency have not been discussed much. Therefore, the authors investigated factors influencing the development of the bypass graft.METHODSIn this retrospective study, the authors evaluated 49 consecutive hemispheres in 47 adult Japanese patients who had undergone ECIC bypass for chronic steno-occlusive cerebrovascular disease. To evaluate objectively the development of the ECIC bypass graft, the change in the area of the main trunk portion of the superficial temporal artery (STA) from before to after bypass surgery (postop/preop STA) was measured. Using the interquartile range (IQR), the authors statistically analyzed the factors associated with excellent (> 3rd quartile) and poor development (< 1st quartile) of the bypass graft.RESULTSThe postop/preop STA ranged from 1.08 to 6.13 (median 1.97, IQR 1.645-2.445). There was a significant difference in the postop/preop STA between the presence and absence of concurrent diabetes mellitus (p = 0.0432) and hyperlipidemia (0.0069). Furthermore, logistic regression analysis revealed that only concurrent diabetes mellitus was significantly associated with poor development of the bypass graft (p = 0.0235).CONCLUSIONSDiabetes mellitus and hyperlipidemia influenced the development of the ECIC bypass graft. In particular, diabetes mellitus is the only factor associated with poor development of the bypass graft.

Early surgical treatment benefits early staged pediatric moyamoya disease--single case report.

PURPOSE: Surgical revascularization for pediatric moyamoya disease improves cerebral blood flow (CBF) and consequently may prevent further ischemic events. However, the timing of the treatment is controversial especially for patients with no ischemic symptom and normal CBF. The purpose of this case report is to inform and infer the surgical treatment timing for pediatric moyamoya disease patients. CASE REPORT: A 10-year-old female patient with unilateral moyamoya disease complaining of only headache as a symptom and whose Suzuki stage was II or in transition to III by angiography and CBF was almost normal was admitted to Tokyo Women's Medical University Hospital. We performed superficial temporal artery-middle cerebral artery (STA-MCA) double anastomoses for the patient because we estimated her headache was derived from low perfusion in the brain. STA-MCA bypass surgery was not only effective for relief of her severe headache but also valid for her cerebral perfusion. Her angiography showed much supply from external carotid artery to intracranial arteries via bypass grafts in 7 months. CONCLUSION: Our case showed early surgical treatment was beneficial for relief of severe headache even for early staged pediatric moyamoya disease patients by improving perfusion pressure and cerebral circulation.

Network-based gene expression analysis of vascular wall of juvenile Moyamoya disease.

SUBJECTS: Little is known about the pathology and pathogenesis of the Moyamoya disease (MMD). To better understand the molecular processes involved in MMD gene expression analysis of Moyamoya artery tissue to a control artery, this study was conducted. METHODS: Tissue samples of two MMD and two non-MMD were profiled using oligonucleotide microarrays. Gene ontology classification of the differentially expressed genes was analyzed, and regulatory functional networks and pathways were identified with a network-based computational pathway analysis tool. Analysis of MMD and control tissue revealed 104 differentially expressed genes. RESULTS: The two major significantly associated gene ontology terms was cellular development and cellular movement. Further network-based analysis showed significant interaction between RNF213 downstream gene networks and the top 3 score gene networks of MMD. Three major nodes of this network were evident in the merged network and were showing interactions with downstream network of RNF213. CONCLUSIONS: Our results demonstrate that cellular development and cellular movement in MMD are the key role of mechanisms.

Moyamoya disease concurrent with Graves' disease treated by direct bypass: clinical features and treatment strategies.

BACKGROUND: Moyamoya disease (MMD) concurrent with Graves' disease (GD) is rare. There is no guideline about optimizing thyroid hormones and the appropriate timing of surgical treatment for MMD with GD. METHODS: We encountered eight patients with MMD and GD presenting with cerebral ischemia who were treated by direct bypass. Thyroid hormones [free thyroxin (fT4) and free triiodothyronine (fT3)], thyroid-stimulating hormone (TSH), and TSH receptor antibody (TRAb) were measured sequentially. After thyrotoxic conditions were medically optimized, revascularization surgery was performed by superficial temporal artery-middle cerebral artery (STA-MCA) double bypass in all cases. Clinical outcomes were estimated by modified Rankin scale (mRS) at discharge and 3 months after surgery. RESULTS: In six patients with thyrotoxicosis, the fT4, fT3, and TRAb (range) at the onset of cerebral ischemia were 4.81-10.30 pg/ml, 13.08-31.90 pg/ml, and 3.5-83.8 IU/l, respectively. At surgery, mean (range) fT3 and fT4 were optimized to 3.02 (1.01-4.87) pg/ml and 1.09 (0.41-1.68) ng/dl, respectively. In the thyrotoxic cases, it took 70-310 days (mean, 142 days) to optimize thyroid hormones before surgery. There was no neurological aggravation after surgery, and outcome was excellent at 3 months with mRS scores ≤2 in all cases. CONCLUSIONS: For MMD concurrent with GD, optimizing thyroid hormones followed by STA-MCA double bypass was successful to prevent cerebral ischemic events.

[Application of Silicone Rubber Stents in Intracranial Arterial Microanastomosis for Vessels with Intimal Dissection:A Technical Note].

Intracranial arterial microanastomosis remains an important neurosurgical technique. Intimal dissection of donor or recipient arteries can cause bypass failure. We used a silicone rubber stent while performing arterial microanastomoses, and achieved an excellent postoperative patency rate. In this study, we evaluated the efficacy of the stent in cases of extensive intimal dissection. In 5 cases involving extensive intimal dissection of vessels out of a total of 856 microanastomoses that were performed between November 2000 and August 2014, we placed a silicone rubber stent in the lumen of the recipient artery for donor to recipient suturing. Surgery was performed in 3 cases of cerebrovascular atherosclerotic disease and in 2 cases requiring cerebral revascularization for the treatment of aneurysm recurrence. In one of the 5 cases in which arterial microanastomosis was performed in the spasm period after subarachnoid hemorrhage, a patent anastomosis could not be confirmed. We observed the following advantages of silicone stent use: clear visualization of the orifice created in the vessel, avoidance of suturing or damaging the contralateral side vessel edges, and maintenance of the shape of the anastomosed vessel segment. These advantages made it easier to visualize the intima and to achieve fixation by using tacking sutures.

[Delayed Traumatic Intracerebral Hematoma during Antiplatelet Therapy after Operations for Ruptured Left ICPC Aneurysm and Right Traumatic Epidural Hematoma: A Case Report].

Delayed traumatic intracerebral hematoma (DTICH) is a rare complication of head injury that appears suddenly after an interval of several days or months. Here, we report a case of DTICH during antiplatelet therapy for vasospasm following surgeries for a ruptured left internal carotid-posterior communicating (ICPC) aneurysm and right acute epidural hematoma (EDH). A 77-year-old man with no medical history was diagnosed with a subarachnoid hemorrhage (SAH) due to rupturing of a left ICPC aneurysm and a right linear fracture of the right parietal bone due to a head injury following the rupture. On day 2, the patient underwent successful clipping of the left ICPC aneurysm. Computed tomography (CT) performed post-clipping revealed a right acute EDH below the linear fracture of the right parietal bone, which was removed immediately. A next-day CT revealed minor contusions in both temporal poles. Fasudil, ozagrel, and cilostazol were administered from Day 3 post-clipping and EDH evacuation to prevent vasospasm. The contusions did not enlarge until Day 10. On Day 11, the patient became comatose, and a huge hematoma was identified in the right temporal lobe to frontal lobe. Although the hematoma was removed immediately, the patient died on Day 13. The hematoma was considered to be a rare case of DTICH that developed from a minor contusion of the right temporal lobe during antiplatelet therapy for vasospasm. In cases of aneurysmal SAH with head injury and contusion, we must pay attention to DTICH and select more deliberate treatment for vasospasm.

A case report of a pediatric traumatic aneurysm with arteriovenous (A-V) fistula CASE-BASED UPDATE.

BACKGROUND: Traumatic intracranial aneurysms (TICAs) are rare, representing less than 5 % of all intracranial aneurysms. Most TICAs are located within the anterior circulation, and less than 10 % of TICAs occur in the posterior circulation. Histopathologically, most TICAs are false aneurysms and have a high risk of rupture or re-bleeding. When they are discovered, careful observation or treatment may be required. Once they are enlarged, they have a high risk of rupture, and immediate treatment is essential. CASE REPORT: For the first time in the literature, we report a rare case of an 8-year-old boy with a TICA in anterior inferior cerebellar artery (AICA) and arteriovenous (A-V) fistula after severe head trauma. Trapping of AICA and resection of the aneurysm was performed. Postoperatively, he has peripheral facial palsy but is otherwise neurologically normal. CONCLUSION: Surgical treatment for traumatic aneurysms is challenging because most of TICAs are histopathologically pseudoaneurysms. It may be technically difficult to perform direct surgery of aneurysms especially located in the posterior circulation, but when the treatment is successful, the outcome was favorable.

A case of bilateral vertebral artery dissection treated by bilateral surgical occlusion and low-flow bypass.

Background: 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. Here, we report a case of bilateral VADA that was successfully treated with staged bilateral VADA occlusion and low-flow bypass. Case Description: A Japanese man in his 40s presented with bilateral VADA with subarachnoid hemorrhage. He had only mild headaches without any other neurological deficits. Subsequently, the ruptured left VADA was surgically trapped. However, on postoperative day 11, the contralateral VADA enlarged. The right VADA was then proximally clipped via a lateral suboccipital approach. Furthermore, a superficial temporal artery-superior cerebellar artery bypass was performed through a subtemporal approach in advance to preserve cerebral flow in the posterior circulation. The bilateral VADA was obliterated, and the patient had an uneventful postoperative course during the 1-year and 6-month follow-up period. Conclusion: Bilateral VADA can be successfully treated with staged bilateral VADA obstruction and low-flow bypass. In this case, as the posterior communicating arteries were the fetal type and the precommunicating segments of the posterior cerebral arteries (P1) were hypoplastic, a low-flow bypass was used to supply the basilar and cerebellar arteries, except the posterior cerebral and posterior inferior cerebellar arteries. Furthermore, low-flow bypass is a less invasive option than high-flow bypass.