Endovascular treatment of A1 segment aneurysms of the anterior cerebral artery

Surgery Versus Endovascular Treatment for Proximal Anterior Cerebral Artery Aneurysms: A Meta-Analysis

BACKGROUND

Proximal anterior cerebral artery (PACA) aneurysms account for less than 1% of all intracranial aneurysms. These aneurysms possess a challenge to surgeons due to their small size, wide base, fragile wall, and accompanying vascular anomalies. Surgery and endovascular treatment are both effective treatment options for PACA aneurysms but there is currently no consensus on which is the method of choice.

OBJECTIVE

A systematic review and meta-analysis was conducted to investigate treatment strategies for aneurysms at proximal anterior cerebral artery.

MATERIAL AND METHODS

The Cochrane Library, EMBASE, PubMed, and Web of Science databases were systematically searched for studies published between January 01, 2000 and December 01, 2020 that investigated surgery and/or endovascular treatment for patients with PACA.

RESULTS AND CONCLUSIONS

Nineteen retrospective studies involving 358 patients met the inclusion criteria. Among these patients, 150 were treated surgically and 208 were treated using an endovascular technique. Preoperative morbidity was significantly greater in the surgical patients compared with the endovascular treated patients but there was no difference between groups in procedural related morbidity. The rates of favorable clinical outcome at time of discharge and at follow-up were statistically significantly greater in the endovascular group compared with the surgical group. Procedural related mortality was 8.7% for the surgical group and 1% in the endovascular group. In summary, our meta-analysis emphasized the safety and efficiency of endovascular treatment, and concluded that it was superior to surgery in acquiring favorable clinical outcome and reducing the perioperative complications. However, surgery was still the preferred treatment strategy for ruptured PACA aneurysms. Preoperative evaluation seems to be of great vital.

Microneurosurgical management of aneurysms of the A1 segment of the anterior cerebral artery: Anatomy and surgical technique

Background:

Aneurysms of the A1 segment of the anterior cerebral artery (ACA) are rare and have characteristics differentiating them from other intracranial aneurysms. Their microsurgical management is challenging and requires different strategies. In this article, we review the surgical anatomy of the A1 segment of the ACA with cadaveric dissections and describe the microsurgical management of complex A1 aneurysms with illustrative cases.

Methods:

A right pterional craniotomy and Sylvian dissection were performed on a formalin-fixed and silicone-injected cadaver head to depict the key anatomic structures and surgical corridors for microsurgical clipping of A1 segment aneurysms. The microneurosurgical management of ruptured and unruptured aneurysms of the A1 segment of the ACA is described with case illustrations.

Results:

The A1 segment of the ACA can be subdivided into proximal, middle, and distal subsegments, the former having abundant perforating branches. Both patients treated with microsurgical clipping had excellent and durable outcomes and postoperative cerebral angiograms showed complete aneurysm occlusion.

Conclusion:

Small A1 aneurysms may require early treatment as their rupture risk appears to be higher. A1 aneurysms are usually embedded in perforators, especially those arising from the proximal A1 subsegment, and require careful distal to proximal microdissection and strategic placement of the aneurysm clip blades. The approach, arachnoid dissection, and angles of attack are carefully planned after accounting for the aneurysm dome projection, precise location of the aneurysm neck and perforators, and the presence or absence of subarachnoid hemorrhage.

Anterior perforated substance region aneurysms: review of a series treated with microsurgical technique

Aneurysms arising from the distal carotid, proximal A1, and proximal M1 that project posteriorly and superiorly toward the anterior perforated substance (APS) are rare. Their open surgical treatment is particularly difficult due to poorly visualized origin of the aneurysm and the abundance of surrounding perforators. We sought to analyze the anatomical and clinical characteristics of APS aneurysms and discuss surgical nuances that can optimize visualization, complete neck clip obliteration, and preservation of adjacent perforators. Thirty-two patients with 36 APS aneurysms were surgically treated between November 2000 and September 2017. Patients were prospectively enrolled in a cerebral aneurysm database and their clinical, imaging, and surgical records were retrospectively reviewed. Twenty-seven aneurysms originated from the distal ICA, 7 from the proximal A1, and 2 from the proximal M1; 15 patients presented with subarachnoid hemorrhage. Careful intraoperative dissection revealed 4 aneurysms originating at the takeoff of a perforator; another 25 had at least 1 adherent perforator. All aneurysms were clipped except for one that was trapped. Postoperatively, 3 patients had radiographic infarctions in perforator territory with only 1 developing delayed clinical hemiparesis. Good outcome (modified Rankin Scale, 0-2) was achieved in 28 patients (88%). APS aneurysms present a challenging subset of aneurysms due to their complex anatomical relationship with surrounding perforators. These should be identified on preoperative imaging based on location and projection. Successful microsurgical clipping relies on optimization of the surgical view, meticulous clip reconstruction, preservation of all perforators, and electrophysiological monitoring to minimize ischemic complication.

Endovascular treatment for aneurysms at the A1 segment of the anterior cerebral artery: current difficulties and solutions

Aneurysms located at the A1 segment of the anterior cerebral artery are considered rare and unique entities. Endovascular treatment (EVT) is effective in preventing aneurysmal bleeding. However, EVT for A1 aneurysms is difficult due to their distinctive configurations. A current review of EVT for A1 aneurysms is lacking. Therefore, we focused on the available literature on this specific issue. To more clearly expound this entity, we also provided some illustrative cases. The A1 segment can be equally divided into the proximal, middle, and distal segments. Proximal aneurysms are most common and difficult to treat via EVT. The A1 segment has a complex anatomy and many important branches. Due to the small size, predominant posterior direction, and sharp upturn of the microcatheter from the parent artery, microcatheter positioning and support is difficult for A1 aneurysms. EVT for A1 aneurysms mainly includes reconstructive and deconstructive strategies. The complications of EVT for A1 aneurysms include aneurysmal perforation, thromboembolic events, and coil protrusion related to stent-assisted embolization. A1 aneurysms represent rare and difficult vascular lesions. EVT is quite challenging for A1 aneurysms due to their distinctive configurations. The outcomes are acceptable.

Safety and efficacy of different therapeutic strategies in the endovascular treatment of anterior cerebral artery aneurysms with different features: A single centre experience

BACKGROUND

Outcomes of endovascular treatment of anterior cerebral artery (ACA) aneurysms are still not well-characterized.

OBJECTIVE

The study aimed to review the clinical effect, procedure-related complications and follow-up outcomes and to evaluate the safety and efficacy of endovascular treatment of ACA aneurysms in our center experience.

METHODS

From August 2014 to August 2018, a total of 75 consecutive patients with 77 ACA aneurysms were treated via the endovascular approach after providing informed consent. A retrospective review of the clinical, radiological, and endovascular details of these patients was conducted.

RESULTS

The mortality and the morbidity in this study were 4% and 9.3%, respectively. Compared with A1 and A2 aneurysms, intraoperative rupture was more common in A3 aneurysms (P = 0.029). Difference between the ruptured and unruptured aneurysms in the distribution of therapeutic strategy (P = 0.003) and immediate embolization degree (P = 0.004) was also significant. Statistical analysis demonstrated that the larger aneurysm (P = 0.031) was, the greater the ratio of aneurysm size to parent artery diameter (P = 0.029) was, the more likely the unruptured aneurysms were to occur ischemic events. Higher Hunt-Hess grade (P = 0.0066) was an independent risk factor for poor clinical outcome.

CONCLUSION

Endovascular treatment is feasible and effective for ACA aneurysms.

Endovascular Treatment of Ruptured Proximal Segment of the Anterior Cerebral Artery Aneurysms: Single-Center Experience and Literature Review

BACKGROUND

Proximal anterior cerebral artery (A1) aneurysms are rare among all intracranial aneurysms and are regarded as difficult to treat endovascularly. Treatment is even more challenging in patients with ruptured aneurysms and acute subarachnoid hemorrhage owing to the small size and proximity to perforators. Though challenging, endovascular treatment can provide favorable outcomes in such patients. We report our case series of endovascular treatment in ruptured proximal A1 aneurysms.

METHODS

Between January 2010 and December 2017, 1200 aneurysms were treated endovascularly at our center. There were 15 patients with 15 ruptured proximal A1 aneurysms who presented with subarachnoid hemorrhage. Five patients underwent simple coiling, 9 underwent balloon-assisted coiling, and 1 underwent catheter protective coiling. Medical records and angiographic results were obtained retrospectively.

RESULTS

All aneurysms were successfully treated with endovascular techniques. Multiplicity rate was 53.3% (n = 8). Initial complete obliteration rate was 93.3% (n = 14), with a 13.3% recurrence rate (n = 2). One patient experienced intraoperative bleeding; this was the only procedure-related complication. Eleven patients (73.3%) had a good clinical outcome. When excluding Hunt and Hess grade 4 patients, the good outcome rate was 81.8%.

CONCLUSIONS

Ruptured proximal A1 aneurysm is a rare condition and is highly associated with multiple aneurysms. Despite being a more difficult and complicated technique, endovascular coiling performed in high-volume, experienced medical centers is an effective modality with excellent clinical outcomes.

Management of Proximal Anterior Cerebral Artery Aneurysms: Anatomical Variations and Technical Nuances

OBJECTIVE

The proximal segment of the anterior cerebral artery (A1) is among the most uncommon locations for occurrence of an intracranial aneurysm. These aneurysms may be missed if small or misinterpreted when they are near the internal cerebral artery bifurcation or Anterior Communicating Artery region. The association with congenital vascular anomalies and multiplicity makes them unique.

METHODS

Seventeen A1 aneurysms were diagnosed in sixteen patients between January 2000 and October 2014 in our institution. A retrospective review of the clinical, radiological, and management (microsurgical and endovascular) details of these patients was conducted.

RESULTS

The incidence of A1 aneurysm was 1.71% of all patients harboring aneurysms and 1.19% of all aneurysms. Half of these patients exhibited subarachnoid hemorrhage. Fourteen aneurysms underwent microsurgical or endovascular intervention. All patients recovered well, except for one patient who died in the postoperative period.

CONCLUSIONS

A1 aneurysms are rare, with wide anatomic variations. In this article, we discuss those variations in detail with illustrative cases and pictures. We also discussed the microsurgical and endovascular strategies to encounter them highlighting the technical challenges.

Endovascular treatment of unruptured A1 segment aneurysms

Aneurysms of the A1 segment of the anterior cerebral artery (A1A) are rare and challenging to treat. Less information is available regarding their management by endovascular approach. We evaluated our experience of endovascular treatment in 15 patients with unruptured A1As. We retrospectively reviewed unruptured A1As treated by embolization at our hospital. The clinical data and angiographic results were reviewed. A special technique involving shaping microcatheter tips was used for catheterization. From September 2009 to December 2012, 15 patients presenting with unruptured A1As were identified. All the patients were treated by selective embolization including five patients with balloon-assisted coiling (BAC) or stent-assisted coiling (SAC). These adjunctive techniques were used to catheterize the sac safely or to protect a branch at the neck. According to the location and direction of the aneurysm, "Z-shaped", "S-Shaped" or "U-Shaped" microcatheter tip shaping was used for microcatheter positioning and stabilization. All patients showed an excellent clinical outcome. A complete aneurysm occlusion was obtained in all the patients. Endovascular treatment of A1As is feasible and associated with good results. Because of their location and close relationship with perforators, endovascular treatment of A1As sometimes requires the use of BAC or SAC. The microcatheter tip shaping technique is very important for coiling. Our results suggest that endovascular treatment is a suitable therapeutic option for unruptured A1As when the aneurysm size is optimal for embolization.