To preserve some of the benefits of traditional clipping surgery such as treatment durability, while pursuing a less invasive approach, we have performed supraorbital keyhole clipping surgery over a 17-year period since 2005. This procedure was conducted in a total of 137 cases of relatively small (mean: 6.0 ± 1.8 mm) unruptured intracranial aneurysms (UIAs). In the anterior circulation, comprising 74 anterior cerebral artery aneurysms and 63 internal carotid artery aneurysms. The mean patient age was 62.6 ± 9.5 years, and the mean craniotomy size was 28.5 ± 3.2 mm. The complete obliteration rate was 94.2%. The mean hospitalization time was 2.8 ± 4.4 days. Postoperative complications were two cases of lacunar infarction (1.5%), one of which (0.7%) was symptomatic (modified Rankin scale [mRS] = 3). Morbidity (mRS ＞2 or mini-mental state examination ＜24) occurred in one case (0.7 %) at 3 months. The mean neurological follow-up period was 6.9 ± 4.0 years, and postoperative mRS did not differ significantly from preoperative mRS. However, cognitive testing and depressive state were significantly improved 3 months postoperatively. The mean radiological follow-up period was 7.6 ± 4.2 years. Regrowth of neck remnants was noted in one of the eight cases (12.5%, 1.4%/year), while aneurysm recurrence occurred in three cases (2.1%, 0.29%/year). Two patients required retreatment (1.5%, 0.20%/year). Treatment of relatively small anterior circulation UIAs by keyhole clipping surgery ensured a good complete clipping rate and durability comparable with that of conventional craniotomy. Hospitalization was short, similar to that of endovascular surgery, and early psychological recovery was assured. We conclude that keyhole clipping is a viable less invasive surgical option.

A 58-year-old man presented with cognitive dysfunction and visual field disturbances and underwent resection of a right temporal lobe glioblastoma. Magnetic resonance imaging (MRI) obtained 4 months after 60 Gy radiation therapy and chemotherapy with temozolomide did not show tumor recurrence or aneurysmal formation. One month later, the patient was transferred to our facility due to sudden-onset headache and nausea. Head computed tomography (CT) and CT angiography revealed an intracerebral hemorrhage in the tumor cavity and an 8 mm aneurysm adjacent to the hematoma at the M2 portion of the right middle cerebral artery. Bypass-assisted parental artery occlusion using the previous craniotomy was performed to prevent rebleeding from the aneurysm. The right Sylvian fissure was opened after harvesting the superficial temporal artery and performing a recraniotomy, securing the M2 portion proximal to the aneurysm. Indocyanine green (ICG) videoangiography under temporary occlusion of the M2 portion precisely detected the target recipient vessel at the surface, and a superficial temporal artery–to–middle cerebral artery bypass was performed. Subsequent removal of the hematoma caused bleeding from the defect of the vessel wall at the aneurysmal neck and demonstrated that the aneurysmal structure was a pseudoaneurysm without a proper aneurysmal wall. The vessel wall defect segment of the M2 portion was trapped using two aneurysmal clips and removed with a pseudoaneurysm. Pathological investigation revealed no vessel structures, such as elastic lamina or endothelial cells, suggesting a pseudoaneurysm. The patient’s postoperative course was uneventful, and he was discharged. In this article, we discuss the pathophysiological mechanisms of de novo aneurysm formation and rupture after the initial treatment of glioblastoma and the validity of surgical intervention when the tumor is well-controlled.

We report a case of spontaneous thrombosis of a ruptured intracranial aneurysm with an unruptured aneurysm in which we failed to recognize the ruptured aneurysm and treated the unruptured aneurysm, which resulted in its re-rupture.

A 61-year-old female with pain extending from the occiput to the back was admitted to the emergency department. She developed seizures in the emergency room and was referred to us because a head computed tomography (CT) scan revealed a diffuse subarachnoid hemorrhage. The 3D computed tomography (3DCTA) and catheter angiography revealed no lesions other than the left distal anterior cerebral artery (ACA) aneurysm, although the localization of the hematoma was atypical. We diagnosed a subarachnoid hemorrhage due to rupture of the distal ACA aneurysm and performed neck clipping. The patient presented with impaired consciousness on the 12th day of hospitalization. The 3DCTA and catheter angiography revealed an aneurysm of the right internal carotid artery, which was determined to be the lesion responsible for the first and second hemorrhages. Coil embolization was performed and the patient was transferred to a rehabilitation hospital with an modified Rankin Scale (mRS) score of 4.

Complete thrombosis of a small aneurysm following rupture is rare. Spontaneous thrombosis of ruptured aneurysms with multiple aneurysms is a risk factor for rebleeding because it circumvents further investigation. The existence of a thrombosed aneurysm should be considered when the pattern of hemorrhage is atypical, and appropriate imaging examinations should be repeated.

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease characterized by thrombocytopenia due to autoantibodies against platelet membrane proteins. Intracranial hemorrhage (ICH) is a rare but severe complication of ITP. We present a case of a 40-year-old female with ICH caused by a ruptured arteriovenous malformation (AVM) in the context of ITP and heart failure. Emergency craniotomy and hematoma evacuation were performed after the preoperative platelet transfusion. Perioperative management focuses on controlling venous bleeding and intracranial pressure complicated by elevated central venous pressure due to heart failure. AVM embolization was performed before cranioplasty to reduce the risk of rebleeding. Rigorous management of heart failure contributed to stabilizing the cerebral edema and bleeding. Persistent thrombocytopenia and multifocal cerebral hemorrhages were observed postoperatively. Corticosteroids and intravenous immunoglobulin therapy were administered, resulting in partial stabilization, and the patient was transferred to a rehabilitation facility. This case highlights the critical importance of a multidisciplinary and strategic approach in managing the interplay between ITP, ruptured AVM, and heart failure, particularly in the context of life-threatening complications.

We report two cases in which carotid endarterectomy was aborted because of the carotid plaque extending into the adventitia (outer layer of the artery). The medical team performed carotid artery stenting instead in both patients. A retrospective analysis of preoperative carotid artery ultrasonography revealed that the hypoechoic zone, usually found between the plaque and adventitia, was absent. In these cases, the plaque and adventitia appeared as a single continuous mass, suggesting that the plaque had infiltrated the adventitia. Although predicting adventitial carotid plaque extension remains challenging, careful attention to the hypoechoic zone on carotid ultrasonography may help to identify such pathological conditions before surgery.

The persistent primitive hypoglossal artery (PPHA) is the second most common of the remnant embryonic arteries. We describe a case of carotid endarterectomy for symptomatic internal carotid artery (ICA) stenosis with ipsilateral PPHA. A 68-year-old man presented to a local hospital with weakness in his left lower extremity and was referred to our hospital after carotid ultrasonography revealed severe stenosis of the right ICA. Head magnetic resonance imaging (MRI) revealed small infarcts in the right cerebellar hemisphere, bilateral occipital lobes, and right frontal lobe, whereas cervical vascular MRI revealed an unstable plaque at the site of stenosis. Angiography demonstrated 70% stenosis of the right ICA, according to North American Symptomatic Carotid Endarterectomy Trial criteria, with the PPHA branched posteriorly from the ICA and anastomosing with the vertebral artery. Under somatosensory evoked potential, electroencephalography, and auditory brainstem response monitoring, an internal shunt was placed between the distal end of the plaque and PPHA bifurcation, and carotid endarterectomy was performed. The patient was discharged postoperatively without any new findings of cerebral infarction or neurological deficits. There are several variations in ICA stenosis with the PPHA, including collateral blood circulation and the height of the PPHA bifurcation. Therefore, individual strategies should be determined to ensure safe treatment for each case.

In symptomatic vertebrobasillar artery stenosis, neither endovascular nor surgical interventions have proven efficacy, and revascularization may be necessary in cases in which the condition is refractory to medical therapy. We report the case of a 67-year-old male with hemodynamic cerebellar and brainstem infarctions due to left vertebral artery V4 occlusion and severe right V4 stenosis, causing repeated syncope with neck rotation to the left. Catheter insertion into the right V1 during digital subtraction angiography (DSA) induced immediate syncope. Despite receiving conservative therapy for 3 weeks, the patient’s syncope persisted. Concerns regarding ischemic risk during prolonged catheterization prompted the decision to perform bypass surgery, which successfully resolved the patient’s syncope.

We report a case of a ruptured basilar artery tip aneurysm in which the common carotid artery was occluded. The patent internal carotid artery distal to the occlusion was exposed via surgical cutdown and used as an access route, and endovascular treatment was performed using an adjunctive technique. An 88-year-old woman presented with subarachnoid hemorrhage caused by a ruptured basilar artery tip aneurysm, classified as WFNS Grade 2, for which endovascular treatment was performed. As it was a wide-neck aneurysm, an adjunctive technique was planned; however, both vertebral arteries showed severe wall irregularities, the right internal carotid artery had severe stenosis, and the left common carotid artery was occluded. Intracranial perfusion was primarily dependent on the posterior circulation. Due to concerns regarding widespread cerebral ischemia from cannulating both vertebral arteries, the patent left internal carotid artery was punctured directly. A microcatheter was guided to the right posterior communicating artery via the left posterior communicating artery, and horizontal stenting was performed, followed by intra-aneurysmal coil embolization. This case demonstrates that, even in challenging anatomical situations, an optimal access route can be established by thoroughly evaluating the vascular anatomy and considering direct puncture techniques.