Cerebral revascularization for complex middle cerebral artery aneurysms: surgical strategies and outcomes in a single center

Complex intracranial aneurysms: a DELPHI study to define associated characteristics

PURPOSE

Intracranial aneurysms present significant health risks, as their rupture leads to subarachnoid haemorrhage, which in turn has high morbidity and mortality rates. There are several elements affecting the complexity of an intracranial aneurysm. However, criteria for defining a complex intracranial aneurysm (CIA) in open surgery and endovascular treatment could differ, and actually there is no consensus on the definition of a "complex" aneurysm. This DELPHI study aims to assess consensus on variables defining a CIA.

METHODS

An international panel of 50 members, representing various specialties, was recruited to define CIAs through a three-round Delphi process. The panelists participated in surveys with Likert scale responses and open-ended questions. Consensus criteria were established to determine CIA variables, and statistical analysis evaluated consensus and stability.

RESULTS

In open surgery, CIAs were defined by fusiform or blister-like shape, dissecting aetiology, giant size (≥ 25 mm), broad neck encasing parent arteries, extensive neck surface, wall calcification, intraluminal thrombus, collateral branch from the sac, location (AICA, SCA, basilar), vasospasm context, and planned bypass (EC-IC or IC-IC). For endovascular treatment, CIAs included giant size, very wide neck (dome/neck ratio ≤ 1:1), and collateral branch from the sac.

CONCLUSIONS

The definition of aneurysm complexity varies by treatment modality. Since elements related to complexity differ between open surgery and endovascular treatment, these consensus criteria of CIAs could even guide in selecting the best treatment approach.

Clinical and Technical Outcomes of Intracranial-Intracranial Bypass for Treating Complex Intracranial Aneurysms: An Analysis of 255 Patients

BACKGROUND

Despite the recent increase in publications centered on intracranial-intracranial (IC-IC) bypasses for complex aneurysms, there is no systematic evidence regarding their outcomes. The purpose was to assess the outcomes of patients subjected to IC-IC bypass for aneurysms.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis, a systematic review was conducted. Criteria for inclusion entailed studies with a cohort of at least 4 patients having undergone IC-IC bypass for aneurysms, detailing at least one outcome, such as patency, clinical outcomes, complications, and procedure-related mortality. When the study included patients who had undergone extracranial-intracranial (EC-IC) bypass, the authors extracted the patency and clinical data to juxtapose them with the results of IC-IC.

RESULTS

Of the 2509 shortlisted studies, 22 met our inclusion criteria, encompassing 255 patients and 263 IC-IC bypass procedures. The IC-IC bypass procedure exhibited a patency rate of 93% (95% confidence interval [CI]: 89%-95%). The patency rate of IC-IC and EC-IC bypasses did not significantly differ (odds ratio=0.60 [95% CI: 0.18-1.96]). Concerning clinical outcomes, 91% of the IC-IC patients had positive results (95% CI: 85%-97%), with no significant disparity between the IC-IC and EC-IC groups (odds ratio=1.29 [95% CI: 0.43-3.88]). After analysis, the complication rate was 11% (95% CI: 5%-18%). Procedure-related mortality was 1% (95% CI: 0%-4%).

CONCLUSIONS

IC-IC bypass is valuable for the treatment of complex intracranial aneurysms, boasting high patency and positive clinical outcomes. Complications are unusual, and procedure-related mortality is minimal. Comparing IC-IC and EC-IC led to no significant differences.

Treatment Strategy of Intracranial Anterior Circulation Aneurysm Presenting with Cerebral Ischemia: A Single-Center Experience

OBJECTIVE

To investigate the clinical characteristics and treatment strategy of anterior circulation aneurysm presenting with cerebral ischemia.

METHODS

We performed a retrospective review of patients with intracranial anterior circulation aneurysms presenting with cerebral ischemia examined in the Fifth Ward of the Neurosurgery Department of Tianjin Huanhu Hospital between September 2016 and September 2023. Data were reviewed for age, sex, presentation, type and size, location, treatment modalities, postoperative complications, clinical and imaging outcomes, and follow-up outcomes.

RESULTS

Among the 13 patients, there were 8 males and 5 females (1.6:1). Their presentations included ischemic stroke (69.23%, 9/13) and transient ischemic attack (TIA) (30.77%, 4/13). The aneurysms were dissecting (46.15%, 6/13), saccular (30.77%, 4/13), and saccular combined with thrombosis (23.08%, 3/13) in shape. There were 6 giant aneurysms, 4 large aneurysms, and 3 microaneurysms. Three (23.08%, 3/13) aneurysms were located at the internal carotid artery (ICA) and 10 (76.92%, 10/13) were located in the middle cerebral artery (MCA). A preoperative magnetic resonance perfusion (MRP) examination was performed in all patients, and 9 (69.23%, 9/13) patients showed hypoperfusion. Treatment modalities included stent-assisted embolization, direct clipping, clipping combined with bypass, resection combined with bypass, isolated combined with bypass, proximal occlusion combined with bypass, and the internal carotid artery constriction combined with bypass. Twelve (92.31%, 12/13) patients had no postoperative complications, and temporary complications occurred in 1 (7.69%, 1/13) patient. Aneurysms disappeared in 11 cases and shrank in 2 cases postoperatively. All patients were followed up for 1 to 72 months. We found no new cerebral infarction, no subarachnoid hemorrhage, and no recurrence or enlargement of aneurysms during the follow-up.

CONCLUSIONS

Intracranial anterior circulation aneurysm presenting with cerebral ischemia is rare. Saccular aneurysms with wide neck or thrombosis and dissected aneurysms of the anterior circulation may result in cerebral ischemic attack caused by distal vascular embolism. Individualized treatment should be performed, and cerebral revascularization is an effective treatment for patients with intracranial anterior circulation aneurysms presenting with cerebral ischemia.

Maxillary artery utilization in subcranial-intracranial bypass procedures: a comprehensive systematic review and pooled analysis

The utilization of the internal maxillary artery (IMAX) in subcranial-intracranial bypass for revascularization in complex aneurysms, tumors, or refractory ischemia shows promise. However, robust evidence concerning its outcomes is lacking. Hence, the authors embarked on a systematic review with pooled analysis to elucidate the efficacy of this approach. We systematically searched PubMed, Embase, and Web of Science databases following PRISMA guidelines. Included articles used the IMAX as a donor vessel for revascularizing an intracranial area and reported at least one of the following outcomes: patency, complications, or clinical data. Favorable outcomes were defined as the absence of neurologic deficits or improvement in the baseline condition. Complications were considered any adverse event directly related to the procedure. Out of 418 retrieved articles, 26 were included, involving 183 patients. Among them, 119 had aneurysms, 41 experienced ischemic strokes (transient or not), 2 had arterial occlusions, and 3 had neoplasia. Furthermore, 91.8% of bypasses used radial artery grafts, and 87.9% revascularized the middle cerebral artery territory. The median average follow-up period was 12 months (0.3-53.1). The post-operation patency rate was 99% (95% CI: 97-100%; I2=0%), while the patency rate at follow-up was 82% (95% CI: 68-96%; I2=77%). Complications occurred in 21% of cases (95% CI: 9-32%; I2=58%), with no significant procedure-related mortality in 0% (95% CI: 0-2%; I2=0%). Favorable outcomes were observed in 88% of patients (95% CI: 81-96%; I2=0%), and only 3% experienced ischemia (95% CI: 0-6%; I2=0%). The subcranial-intracranial bypass with the IMAX shows excellent postoperative patency and considerable favorable clinical outcomes. While complications exist, the procedure carries a minimal risk of mortality. However, long-term patency presents heterogeneous findings, warranting additional research.