Kento Sasaki

Ruptured dissecting aneurysms (DAs) of the anterior cerebral artery (ACA), particularly at the A1–A2 junction, are rare and diagnostically challenging, especially in young patients. Conventional treatment options may be limited due to anatomical constraints and the lesion's fragility. We report the case of a 23-year-old male who presented with diffuse subarachnoid hemorrhage and seizure. Initial imaging failed to identify the bleeding source. On follow-up, computed tomography angiography revealed subtle findings suggestive of a dissection at the right A1–A2 junction, which was subsequently confirmed by digital subtraction angiography. Considering the lesion's morphology and location, the aneurysm was treated with a flow diverter (Pipeline Flex with Shield Technology) following clinical stabilization. The patient recovered without neurological deficits and was discharged in good functional condition. This case highlights the potential of flow diversion as an effective treatment strategy for ruptured DAs in the distal ACA. Early recognition through repeat imaging and individualized multidisciplinary planning may contribute to favorable outcomes in anatomically complex lesions.

Background: The surgical treatment of third ventricular craniopharyngiomas (CPs) is challenging due to their deep location and proximity to critical neurovascular structures. This report presents the use of the extended endoscopic endonasal approach for the resection of a third ventricular CP. Case Description: A 48-year-old male patient was admitted to the hospital with visual disturbances and weight gain (body mass index 42.6 kg/m²) over the past 12 months. Preoperative contrast-enhanced magnetic resonance imaging revealed a 30-mm solid mass located within the third ventricle. The patient underwent an extended endoscopic endonasal transplanum transtuberculum approach, providing direct access to the tumor. The postoperative period was uneventful, with no cerebrospinal fluid (CSF) leakage observed. Conclusion: The extended endoscopic endonasal approach is a safe and effective technique for the resection of suprasellar and third ventricular CPs, offering direct access while avoiding brain retraction. Dural suturing plays a key role in skull base reconstruction, reducing the risk of postoperative CSF leakage.

Background: This report presents a rare case of trigeminal neuralgia (TN) caused by a radicular arteriovenous fistula (AVF). Case Description: A 58-year-old woman presented with severe pain in the right lower jaw, typical of TN. Magnetic resonance imaging showed a vascular signal near the trigeminal nerve. Direct surgery revealed tortuous vessels on the dorsal surface of the nerve, with no offending vessels identified at the root entry zone. Digital subtraction angiography (DSA) confirmed a radicular AVF fed by the trigeminocerebellar artery, with venous drainage into the superior petrosal sinus through the petrosal vein. Endovascular embolization with n-butyl cyanoacrylate resulted in complete obliteration of the fistula and symptom resolution. Although a small pontine infarction occurred, no long-term deficits were observed. Follow-up DSA confirmed no recurrence. Conclusion: To the best of our knowledge, this represents the first documented case of a trigeminal radicular AVF, highlighting the importance of recognizing vascular anomalies and efficacy of endovascular treatment in managing TN.

Background: Aneurysmal subarachnoid hemorrhage caused by cerebral aneurysm rupture has a poor prognosis, with mortality exceeding 30% despite treatment advancements. Surgical neck clipping remains the standard for preventing rupture, but intraoperative rupture rates vary significantly (3–50%) and are influenced by vascular complexity and technical challenges. Thinning of the vascular wall near the aneurysm neck, particularly with microaneurysm formation, has emerged as a significant risk factor, yet these changes often go undetected in preoperative imaging.Objective: This study aimed to evaluate the utility of computational fluid dynamics (CFD) analysis for predicting microaneurysm formation in the parent artery adjacent to unruptured cerebral aneurysms, using the parent artery radiation sign (PARS) as a predictive marker.Methods: We conducted a single-center, retrospective observational study of 89 patients with unruptured middle cerebral artery (MCA) aneurysms treated with neck clipping from May 2020 to April 2022. Based on preoperative three-dimensional computed tomography angiography (3D-CTA), CFD analysis identified PARS through specific hemodynamic indicators. Intraoperative findings were analyzed and compared between PARS-positive and PARS-negative groups. The sensitivity and specificity of PARS for predicting microaneurysm formation were investigated.Results: Of the 87 aneurysms analyzed, 25 (28.7%) were PARS-positive, and 62 (71.3%) were PARS-negative. Microaneurysms were identified intraoperatively in nine cases, eight of which were in the PARS-positive group. The sensitivity and specificity of PARS for detecting microaneurysms were 89 and 78%, respectively. The positive likelihood ratio was 4.1, while the negative likelihood ratio was 0.142.Conclusion: CFD analysis using PARS offers a reliable method for predicting microaneurysm formation in the parent artery, potentially guiding surgical planning and reducing intraoperative rupture risk. While promising, these findings are limited by the retrospective, single-center design, highlighting the need for further research in larger, multicenter cohorts. Incorporating CFD analysis into preoperative assessment could significantly enhance the safety and outcomes of neck clipping procedures for unruptured cerebral aneurysms.

Aneurysm arising from the A1 segment of the anterior cerebral artery is rare. Aneurysm of the A1 segment even being small tend to rupture early. They tend to develop along the with various vascular anomalies of the vessels arising from the A1 segment. Use of computational fluid dynamics and hemodynamic consideration is of importance in this aneurysm. In this report we describe a 57-year-old woman with a small, unruptured A1 segment aneurysm arising from the proximal segment of the posterior surface of A1, and pointing posterior-inferiorly with multiple perforators entangling around for which microsurgical clipping was done. Intraoperative clipping of the aneurysm and salvaging the multiple perforators were challenging. We report a rare case of an A1 segment aneurysm arising from the posterior surface facing with multiple perforators. It is of significance to understand that a small, unruptured A1 aneurysm can arise from the posterior surface of the A1 segment with projection posterior-inferiorly making it deeper in location with multiple perforators entangling it; hence, it is challenging to treat without causing neurological deficits.

Introduction Acute subdural hematomas (ASDHs) have a high mortality rate and unfavorable outcomes especially in the elderly population even after surgery is performed. The conventional recommended surgeries by the Brain Trauma Foundation in 2006 were craniotomies or craniectomies for ASDH. As the world population ages, and endoscopic techniques improve, endoscopic surgery should be utilized to improve the outcomes in elderly patients with ASDH. Materials and Methods This was a single-center retrospective report on our series of six patients that underwent endoscopic ASDH evacuation (EASE). Demographic data, the contralateral global cortical atrophy (GCA) score, evacuation rates, and outcomes were analyzed. Results All patients' symptoms and Glasgow Coma Scale improved or were similar after EASE with no complications. Good outcome was seen in 4 (66.7%) patients. Patients with poor outcome had initial low Glasgow Coma Scale scores on admission. The higher the contralateral GCA score, the higher the evacuation rate (r = 0.825, p ≤ 0.043). All the patients had a GCA score of ≥7. Conclusion EASE is at least not inferior to craniotomy for the elderly population in terms of functional outcome for now. Using the contralateral GCA score may help identify suitable patients for this technique instead of just using a cut-off age as a criteria.

Contrast-induced encephalopathy (CIE) is a rare neurological complication that occurs after the use of contrast medium in various angiographic procedures. Symptoms can be different, from headache to severe neurological deficit and coma. In the articles published to date, symptoms appeared immediately after application of contrast agent or within 24 hours. Here we present two cases of patients in whom CIE developed delayed after endovascular treatment.

Objective This study compared intraoperative findings with preoperative computed tomography angiography (CTA) and computational fluid dynamics (CFD) analysis of perianeurysmal findings for the indication of possible vessel wall thinning. Materials and Methods Participants comprised 38 patients with unruptured middle cerebral artery aneurysms treated by surgical clipping at our hospital between May 2020 and April 2021. We defined parent artery radiation sign (PARS) as the presence of each of the following three findings in CFD analysis based on preoperative CTA: (1) impingement of the stream line on the outer parent vessel wall of the aneurysm; (2) radiation of wall shear stress vectors outwards from the same site; and (3) increased wall pressure compared with the surrounding area. CFD analysis showing PARS was compared with intraoperative findings. Results In all nine cases with PARS, no morphological abnormalities were found in the same area on CTA. However, intraoperative findings showed thinning of the parent artery wall in one of the nine cases and formation of a very small mass in three cases, differing from CTA findings. All nine patients underwent additional clipping and/or wrapping and coating at the site of PARS. Conclusion Detecting thinning of the vessel wall or the presence of a microaneurysm may be difficult in endovascular therapy, which is based on the visualization of the vessel lumen. CFD analysis suggests the necessity of confirming findings for the vessel wall around an aneurysm by direct manipulation, as the presence of PARS may indicate partial thinning of the vessel wall or formation of a microaneurysm.

Introduction Bypass surgery is a challenging operative procedure that requires surgical excellence. Achieving the skills required for vascular surgery is difficult to master in the operating room without intensive microsurgical training. Various models have been developed to provide training to young neurosurgeons and increase dexterity and patient safety. Bypass surgery requires complex microsurgical techniques. Methods Microanastomosis training was performed on plastic tubes and chicken wings for 2 months. Each microanastomosis was evaluated by a senior author. Results An improvement in the quality and patency of microanastomosis was observed. Conclusion Microsurgical simulation training can contribute to the improvement of surgical skills and dexterity.