Contralateral Approach to Coil Embolization of Proximal A1 Aneurysms Using the Anterior Communicating Artery

Current state of endovascular treatment of anterior cerebral artery aneurysms

The locations of anterior cerebral artery (ACA) aneurysms vary, and various aneurysms can occur along the course of the ACA. Ruptured and some unruptured ACA aneurysms may require aggressive treatment to avoid bleeding or rebleeding. Although open surgery is an effective treatment for ACA aneurysms, endovascular treatment (EVT) is becoming an alternative treatment in select cases. EVT techniques for ACA aneurysms often vary and are performed on a case-by-case basis according to the nature and location of the aneurysm. To better understand the EVT strategy for ACA aneurysms, it is necessary to review EVT for ACA aneurysms. In this review, the following topics are discussed: ACA anatomy and anomalies, classifications of ACA aneurysms, the natural history of ACA aneurysms, open surgery and EVT statuses for ACA aneurysms, EVT techniques for various ACA aneurysms, and the prognosis and complications of EVT for ACA aneurysms. According to our review and experience, traditional coiling EVT is still the preferred therapy for most ACA aneurysms. For A1 aneurysms, EVT is challenging. After the selection of appropriate cases, deployment of a flow diverter and Woven EndoBridge device can result in a good prognosis for patients with ACA aneurysms. In addition, parent artery occlusion can be used to treat A1 aneurysms with good collateral circulation and some distal ACA aneurysms. In general, EVT is gaining popularity as an alternative treatment option for ACA aneurysms.

Endovascular management of saccular aneurysms of the proximal A1 segment: technical particularities and long term outcomes

BACKGROUND

Saccular aneurysms of the proximal A1 segment (SAPA1) are rare, but their treatment is challenging and scarcely described in the literature. We report the immediate and long term outcomes of their endovascular management.

METHODS

We retrospectively analyzed all consecutive SAPA1 cases treated endovascularly at our center between 2003 and 2023. Per procedural complications and radioclinical outcomes were prospectively recorded.

RESULTS

Among 2468 patients followed up for aneurysms, 12 (0.49%) had an SAPA1 (average age 53.8±9.6 years, 9 women). The SAPA1 averaged 3.3 mm, all posteriorly oriented. Ten were ruptured (83.3%). Initial treatments included conventional coiling or balloon assisted coiling (CC/BAC) for nine aneurysms, and proximal A1 segment focal occlusion (PA1FO) for three. Initial occlusion was deemed satisfactory in all instances: total occlusion in eight cases (67%) and subtotal occlusion in four cases (33%). Four aneurysmal perforations occurred (33%), all during CC/BAC on ruptured aneurysms. Over a 10.2 year average follow-up, six recanalizations (50%) were noted, all after initial CC/BAC: three were early (≤14 days), with one causing fatal rebleeding. No recanalizations after PA1FO was observed (five in total, two as a complement after CC/BAC). Favorable clinical outcomes (modified Rankin Scale score of 0-2) were seen in 91% of cases (11/12) at the last follow-up.

CONCLUSIONS

Selective coiling of the aneurysmal sac is technically difficult due to their small size and the complex microcatheterization pathway. This method presents a significant risk of aneurysmal perforation, especially in ruptured cases, and a high rate of recanalization. PA1FO, when collateralization permits, appears to be a reliable therapeutic alternative offering favorable long term outcomes.

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.

[Endovascular Treatment of Cerebral Aneurysms: Technical Options in Coil Embolization]

Since the endosaccular coil embolization technique was introduced as an alternative for treating selected patients with aneurysms, it has become a mainstay of treatment for cerebral aneurysms. In lesions with a neck larger than the aneurysmal body, an irregular shape, or arterial branches incorporated within the sac, endovascular treatment using detachable coils are traditionally contraindicated because of technical difficulties. Coil embolization has evolved as a result of both the development of related devices and the introduction of technical improvements using various devices. Use of various technical and device options can make endovascular treatment of cerebral aneurysms safer and can widen the treatment indications. Various technical options, including the technical modification of device-assisted techniques, will be presented, and the related practical points will be discussed in this issue.

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.