Fenestrated clipping of previously coiled posterior-superiorly projecting anterior communicating artery aneurysms: How I do it.

BACKGROUND: Anterior communicating artery (ACOM) aneurysms are among the most common aneurysms associated with aneurysmal subarachnoid hemorrhage (International Study of Unruptured Intracranial Aneurysms I (N Engl J Med 339:1725-1733, 1998), Wiebers (Lancet 362:103-110, 2003)). Surgical clipping of posterior-superiorly projecting ACOM aneurysms can be challenging, as the ipsilateral A2 can interfere with clip trajectory and ACOM perforating vessels obstructed from view. Intraluminal coils can further increase the difficulty of the procedure. METHOD: The relevant surgical anatomy with illustration is presented. A video detailing our technique on an illustrative case is provided. CONCLUSION: Surgical clipping of posterior-superiorly projecting ACOM aneurysms can require complex clip configurations. We describe the key steps of posterior-superiorly projecting ACOM aneurysm clipping through a lateral supraorbital craniotomy and fenestrated tandem clipping.

[Interhemispheric Approach for Ruptured Anterior Communicating Artery Aneurysms].

The interhemispheric approach is very useful for the safe and reliable clipping of ruptured anterior communicating aneurysms. This approach enables surgeons to directly visualize the aneurysm and the surrounding vessels, including perforators, and provides a wide surgical corridor for clip insertion from multiple directions. Furthermore, in challenging situations, this approach facilitates vascular reconstruction without the need for graft harvesting. However, because of the procedural difficulty, many young and inexperienced neurosurgeons may hesitate to perform this technique. Therefore, this study aimed to provide useful tips, based on intraoperative photography, for skin and dural incisions, prevention of cerebrospinal fluid leakage and olfactory impairment, and fundamental steps for opening tight interhemispheric fissures. Finally, representative challenging cases that were adequately managed using the advantages of this approach are presented.

[Treatment Choice for Ruptured Intracranial Aneurysm in the Hybrid Era].

Long-term follow-up results from the International Subarachnoid Aneurysm Trial suggest that coiling is preferable for ruptured aneurysms treatable with both modalities. This finding has led to a growing trend towards coiling for these patients. At our institute, coiling is now the first-line treatment for ruptured aneurysms, with exceptions for middle cerebral artery aneurysms. We also favor direct surgery for small ruptured aneurysms(<3 mm), cases with massive intracerebral hematoma, or situations requiring bypass surgery. While early rebleeding after coiling is uncommon, it carries a certain risk. Therefore, we sometimes choose clipping for ruptured anterior communicating artery or posterior communicating artery aneurysms if clipping poses minimal technical difficulty. To achieve optimal outcomes for ruptured aneurysms, a combined approach is crucial. This involves safe and effective endovascular treatment alongside necessary direct surgical interventions.

[Intraoperative Challenges in Endovascular Treatment for Ruptured Intracranial Aneurysms].

In aneurysmal subarachnoid hemorrhage, the highest therapeutic priority is to ensure immediate hemostasis without intraprocedural complications. This article outlines the possible intraoperative coil embolization complications for ruptured intracranial aneurysms and discuss strategies for their prevention and treatment.

[How We Do It (2)].

The treatment landscape for ruptured cerebral aneurysms is undergoing a paradigm shift. While endovascular therapy is increasingly favored, the future demands minimally invasive approaches that prioritize both safety and a definitive cure. At our center, we meticulously tailor the treatment strategy for ruptured aneurysms to each patient. This strategy considers the aneurysm's morphology, patient characteristics, and the crucial balance between invasiveness, safety, and achieving a cure. Notably, in the hybrid era, we strive to maintain a strong foundation in both direct surgical and endovascular techniques. This ensures that our surgeons can continue to provide future patients with safe and highly curative treatment options.

[Clipping via the Transsylvian Approach:From Basic to Advanced Surgical Techniques].

The transsylvian approach is one of the most commonly used approaches in neurosurgery and is essential for clipping aneurysms located in the anterior cranial circulation, such as the middle cerebral artery, internal carotid artery, and anterior communicating artery. Moreover, basilar artery aneurysms can be clipped using this approach, albeit with some modifications. Important tips for dissecting the Sylvian fissures include reliable visualization, anatomical recognition, and steady manipulation. The actual steps are as follows: determine the affiliation of the arteries and veins, gently move the brain to create a wide space, cut the arachnoid mater, and follow the course of the arteries. In case of subarachnoid hemorrhage, irrigation and flushing out the hematoma is the key step involved in recognizing the structure and safely performing surgery. Here, we describe the basic key operative techniques for performing clipping via the transsylvian approach.

[Neck Clipping via Subtemporal Approach].

The subtemporal approach offers the advantages of a wide surgical field in the anteroposterior direction and easy access to the proximal basilar artery. This approach can be adapted to treat low-positioned aneurysms using a tentorial incision, known as the subtemporal transtentorial approach. However, a disadvantage of the subtemporal approach is the risk of injury to the temporal lobe. To mitigate this risk, it is important to ensure proper positioning, adequate cerebrospinal fluid drainage, preservation of the bridging veins, and intermittent retraction of the temporal lobe.

[Microsurgery for Vertebral and Posterior Inferior Cerebellar Artery Aneurysms via Lateral Suboccipital Craniotomy].

Among ruptured intracranial aneurysms, aneurysms of the vertebral artery(VA) and posterior inferior cerebellar artery(PICA) are relatively rare, and they exhibit distinct characteristics. These include: 1) a high frequency of diverse aneurysmal morphologies, such as fusiform or dissecting aneurysms; 2) proximity to the lower cranial nerves; 3) the presence of perforators to the medulla oblongata; and, 4) obstruction to the surgical approach by specific bony structures, such as the occipital condyle and jugular tubercle. Consequently, these aneurysms often require interventions that are more complex than simple clipping or coiling, which is typical for anterior circulation aneurysms. Interventions include skull base techniques such as the far-lateral approach and revascularization procedures such as occipital artery(OA)-PICA bypass. Despite these complexities, the rarity of these aneurysms and the recent advancements in endovascular procedures pose challenges for young neurosurgeons in acquiring adequate microsurgical experience. This narrative review addresses the clinical features of VA and PICA aneurysms, the history and variations in the lateral suboccipital approach for these aneurysms, and several bypass techniques for reconstructing the PICA. Lastly, we illustrate our current microsurgical practices through a case presentation accompanied by a surgical video showcasing both the far-lateral approach and the OA-PICA bypass.

Study protocol of the ASTOP trial: A multicenter, randomized, double-blind, placebo-controlled trial of presurgical aspirin administration for the prevention of thromboembolic complications of coil embolization for ruptured aneurysms.

RATIONALE: Thromboembolism is a serious complication of endovascular treatment for ruptured cerebral aneurysms. The administration of antiplatelet agents before endovascular treatment for ruptured cerebral aneurysms may reduce the risk of thromboembolic complications. AIM: This study aimed to assess the safety and efficacy of preoperative aspirin administration in endovascular treatment for ruptured cerebral aneurysms. SAMPLE SIZE ESTIMATES: Assuming a 15% incidence rate of both intraoperative thromboembolic morbidity and symptomatic ischemic lesions on magnetic resonance imaging diffusion-weighted imaging scans assessed by an Independent Review Committee, a sample size of 484 will be required to detect a 10% improvement with aspirin administration with 90% power using the Pearson's chi-square test at a two-sided significance level of 2.5% for each primary outcome, after accounting for a 5% dropout rate. METHODS AND DESIGN: ASTOP is a multicenter, randomized, double-blind, placebo-controlled clinical trial. A total of 484 patients with ruptured cerebral aneurysms receiving coil embolization within 72 h of onset will be randomly assigned 1:1 to receive 200 mg of aspirin or placebo before the procedure. STUDY OUTCOMES: The primary outcomes will be the incidence rates of intraoperative thromboembolic complications and symptomatic ischemic lesions on magnetic resonance imaging diffusion-weighted imaging scans evaluated by the Independent Review Committee. The secondary outcomes will be the incidence rate of cerebral ischemic events and all bleeding events within 14 days of enrollment and functional outcomes defined by the modified Rankin Scale score at 90 days. DISCUSSION: This trial will provide valuable data on the role of antiplatelet agents during endovascular treatment for ruptured cerebral aneurysms. TRIAL REGISTRATION: Registration: Japan Registry of Clinical Trials, Identifier: jRCTs031210421.

Zygomatic Anterolateral Temporal Approach for P1/P2 segment complex posterior cerebral aneurysm: a single-center retrospective study.

Treating complex posterior cerebral artery (PCA) aneurysms, such as fusiform, giant, and dissecting aneurysms, poses significant challenges. Parent artery occlusion carries a risk of ischemic stroke and fails to alleviate mass effects. This study aims to analyze the technical nuances and patient outcomes of treating complex PCA aneurysms, ranging from the P1 to P2P segments, using a Zygomatic Anterolateral Temporal Approach(ZATA) combined with flow reconstruction. This study was a retrospective study. Surgical treatment was performed on twelve patients with complex PCA aneurysms located in the P1 to P2P segments. Ten patients underwent flow reconstruction including Superficial Temporal Artery(STA)-Middle Cerebral Artery(MCA),Internal Maxillary Artery(IMA)-Radial Artery(RA)-MCA,STA-PCA(P2), and IMA-RA-PCA(P2). The aneurysm occlusion rate, surgical complications, and patient prognosis, including stroke occurrence/ modified Rankin Scale(mRS), were recorded and analyzed. Using the ZATA, all twelve complex PCA aneurysms were successfully clipped/resected/trapped. This included two high-position aneurysms (> 3 mm above the posterior clinoid process) at the P1/P2 junction and three P2P aneurysms. The mass effects of six large or giant aneurysms were resolved or alleviated. Postoperative and follow-up CTA/DSA confirmed the patency of the bypass vessels. Four patients experienced strokes in the perioperative period, with three ischemic and one hemorrhagic. The median follow-up period was 28.5 months. At the last follow-up, the good prognosis rate (mRS ≤ 2) was 83.3%, and one patient had died. Clipping/resection/trapping of aneurysms via the ZATA, combined with flow reconstruction, is a feasible option for treating complex PCA aneurysms from the P1 to P2P segments. This approach helps maintain or improve cerebral perfusion in the affected vascular territory.

Letter to Editor, "Giant unruptured middle cerebral artery aneurysm revealed by intracranial hypertension: is a systematic decompressive hemicraniotomy mandatory?

This study by Aboukais et al. (2024) evaluates postoperative outcomes in patients with unruptured giant middle cerebral artery (MCA) aneurysms associated with intracranial hypertension and midline brain shift. Analyzing data from 2012 to 2022, the authors compare surgical approaches, emphasizing the potential benefits of systematic decompressive hemicraniotomy in improving patient outcomes. While the study's findings are valuable, the small sample size and absence of a control group limit its generalizability. The retrospective nature of the study introduces potential biases, and long-term cognitive outcomes are not fully explored. Future research should involve larger, prospective cohorts with control groups, incorporating advanced imaging and monitoring techniques to enhance surgical precision and long-term recovery assessments. This study provides important insights but underscores the need for further investigation to optimize treatment strategies for this complex condition.

Treatment factors to suppress delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage based on VASOGRADE: multicenter cohort study.

Delayed cerebral ischemia (DCI) is one of the most important outcome determinants for aneurysmal subarachnoid hemorrhage (aSAH). VASOGRADE, which combines World Federation of Neurological Surgeons grade and modified Fisher grade, is a useful scale for predicting DCI after aSAH. However, no studies have investigated whether VASOGRADE influences the treatment options. We retrospectively analyzed 781 aSAH patients who were prospectively enrolled in 9 primary stroke centers from 2013 to 2021. The total cohort consisted of 76 patients (9.7%) with VASOGRADE-Green, 390 patients (49.9%) with VASOGRADE-Yellow, and 315 patients (40.3%) with VASOGRADE-Red. Worse VASOGRADE had higher incidences of DCI, which occurred in 190 patients (24.3%). As only 5 patients (6.6%) with VASOGRADE-Green developed DCI, we searched for DCI-associated factors in patients with VASOGRADEs-Yellow and -Red. Multivariate analyses revealed independent treatment factors suppressing DCI as follows: no postoperative hemorrhagic complication, combined administration of fasudil hydrochloride and cilostazol, combination of clipping and cisternal drainage, and coiling for VASOGRADE-Yellow; and clipping, and administration of fasudil hydrochloride with or without cilostazol for VASOGRADE-Red. The findings suggest that treatment strategies should be determined based on VASOGRADE to prevent DCI after aSAH.

AB040. A complication of recurrent artery of Huebner infarction after resection of an anterior cerebral artery thrombotic giant intracranial aneurysm: case report and literature review.

BACKGROUND: Giant aneurysms, comprising 3-5% of all intracranial aneurysms, pose a considerable challenge due to their heterogeneity and complex vascular anatomy. Defined as aneurysms exceeding 2.5 cm in diameter, they often develop intraluminal thrombosis. Despite advancements in neurosurgical techniques, managing giant aneurysms remains complex and highly individualized. Thrombotic giant aneurysms are particularly problematic due to their size and thrombosis potential. This case report is unique as it presents the first documented instance of recurrent artery of Heubner (RAH) infarction following surgical resection of a giant thrombotic aneurysm. CASE DESCRIPTION: A 53-year-old man with no prior systemic presented to our emergency department due to progressive left-sided weakness and slurred speech. Magnetic resonance imaging (MRI) of brain revealed a thrombotic giant intracranial aneurysm on right anterior cerebral artery (ACA). Surgical resection was performed using a right pterional craniotomy. During surgery, the aneurysm was confirmed to be completely thrombosed and was excised. Postoperatively, the patient experienced a generalized seizure and was intubated. Brain MRI revealed a new infarction in the RAH territory. Despite initial complications, the patient showed significant recovery with rehabilitation, regaining most motor functions by the 6-month follow-up. CONCLUSIONS: This case emphasizes the critical importance of comprehensive preoperative evaluation, particularly in assessing small perforating branches and collateral circulation. It highlights the challenges in managing giant aneurysms and the necessity of anticipating potential postoperative complications. This report adds valuable insights into the clinical management and surgical planning for giant aneurysms, particularly those involving the ACA and RAH.