Revascularization of the Anterior Inferior Cerebellar Artery Using Extracranial and Intracranial Donors: A Morphometric Cadaveric Study

Treatment strategies for saccular anterior inferior cerebellar artery aneurysms: a systematic review

INTRODUCTION

The anterior inferior cerebellar artery (AICA) plays a crucial role in cerebellar blood supply, and AICA aneurysms are relatively rare, comprising less than 1-1.5% of all brain aneurysms. Understanding their clinical scenarios, management approaches, and outcomes is essential. This systematic review analyzes data from 86 studies to comprehensively explore AICA aneurysms.

MATERIALS AND METHODS

The process of obtaining relevant research, which includes patients with AICA aneurysms, was carried out using the PubMed, Web of Science, and Scopus databases. This review exclusively included extensive papers written in English. The search included the MeSH phrases "Anterior inferior cerebellar artery aneurysm" and "AICA aneurysm." Microsurgical and endovascular treatments were compared using statistical analysis, exploring demographics, risk factors, treatment modalities, and clinical outcomes.

RESULTS

The review includes 85 case reports and one retrospective study, totaling 140 patients. The study reveals a diverse patient profile with a slight female predominance (65%), a mean age of 50.7 years, and an 82.86% prevalence of no identified risk factors. Ruptured aneurysms accounted for 55%, with microsurgery and endovascular procedures accounting for 70.71% and 27.86%, respectively. The mortality rate was 2.86%, and no significant differences were found in rebleed, recurrence, or mortality rates between treatment groups.

CONCLUSION

Microsurgical and endovascular interventions demonstrate comparable effectiveness, with microsurgery showing superiority in specific situations. Therefore, tailoring treatment is crucial to individual patient needs. Subgroup analyses highlight demographic-specific trends, guiding clinicians in managing this rare pathology.

Three types of end-to-side microvascular anastomosis training models using rat common iliac arteries

Background

: Instead of only practicing these perfectly matched end-to-side anastomoses in microsurgical laboratories, we must learn how to perform these so-called “imperfect” end-to-side anastomoses in the laboratory.

Methods

Three types of end-to-side microvascular anastomoses using the rat common iliac artery (CIA), one with the proximal end of the CIA to the contralateral side of the CIA, another with the distal end of the CIA to the contralateral side of the CIA, and the third with the distal end of the CIA to the ipsilateral side of the common iliac vein (CIV), were presented to simulate different end-to-side anastomosis situations in a microsurgical laboratory. Diameters of CIA and CIV, distances between temporary clips, the length of arteriotomy or venotomy, and the distribution of stitches were recorded. The patency rates were evaluated immediately after the anastomosis was completed and 30 min later. After animal euthanasia, the donor vessel was cut close to the anastomotic site, and the orifice size and intimal attachment were evaluated by inspecting them through inside the vessel.

Results

The diameters of the CIA and CIV were 0.8–1.2 mm and 1.2–1.5 mm, respectively. The end-to-side microvascular anastomosis arteriotomy or venotomy is approximately 2.00–2.50 mm, the distance between the aneurysm clips on the recipient CIA or CIV is approximately 4.00–7.00 mm, and the distance between the corner of the arteriotomy or venotomy and the temporary aneurysm clip was 1.00–3.00 mm. Three types of end-to-side anastomoses using the CIA were successfully performed, and 100% patency rates were achieved immediately and 30 min postoperatively. Good distribution of stitches, wide orifice, and intimal attachment were recorded in the study in all groups.

Conclusions

Three types of end-to-side anastomoses using rat CIAs could be efficiently used to mimic three different anastomotic situations.

Endovascular treatment of anterior inferior cerebellar artery trunk aneurysms

BACKGROUND

The anterior inferior cerebellar artery (AICA) is a very slender and anatomically variable artery that gives off many important perforating arteries that feed the brainstem and nerve-related arteries that feed the inner ear and labyrinth. AICA trunk aneurysms are rare entities that are also difficult to manage. At present, endovascular treatment (EVT) is the preferred choice; however, the understanding of EVT for AICA trunk aneurysms is limited.

METHODS

In this article, we present a literature review on EVT for AICA trunk aneurysms. To promote understanding, we would also provide some illustrative educational cases of our institute.

RESULTS

Aneurysms along the AICA trunk can occur alone (isolated AICA aneurysm) or secondary to cerebrovascular shunts (flow-related AICA aneurysm). According to their anatomical location, they can also be divided into proximal and distal types. At present, EVT is the mainstream treatment, mainly including selective coiling with parent artery preservation and parent artery occlusion. Both coils and liquid embolization materials can be used.

CONCLUSIONS

For AICA trunk aneurysms, EVT is a reasonable choice and should be based on the specific anatomical location, pathology, and collateral circulation. However, there is still controversy as to the specific type of treatment that should be chosen.

Challenges in Using the Posterior Inferior Cerebellar Artery for Revascularization of the Anterior Inferior Cerebellar Artery: A Microsurgical Anatomic Study

BACKGROUND

A bypass is usually required to prevent ischemia during the treatment of anterior inferior cerebellar artery (AICA) aneurysms. The intracranial (IC)-to-IC bypass provides several advantages over the extracranial-to-IC bypass in the posterior fossa. However, there are only 2 case reports about AICA revascularization with the posterior inferior cerebellar artery (PICA). We aimed to investigate the microsurgical anatomical challenges for PICA to AICA anastomosis.

METHODS

Ten cadaveric heads injected with colored silicone were inspected on both sides using a lateral transcondylar approach. After the donor and recipient arteries were examined from the posterior side, neurovascular contents of the posterior fossa were excised and the origin, course, and variations of both arteries were investigated from the anterior view. The diameters of the AICA and PICA segments and the intersegment distance were measured.

RESULTS

PICA variations and posteromedial origins from the vertebral artery were identified in 8 of the 20 right and 6 of the 20 left sides, and the first segment of the PICA was not present in 7 sides. Furthermore, in 18 sides, the PICA was trapped between the lower cranial nerves and dentate ligaments. Therefore the donor artery could not be brought closer than 1 cm to the recipient artery in 19 sides. Moreover, AICA variations were identified in 6 sides, and in 12 sides, the diameter of the recipient artery was <1 mm.

CONCLUSIONS

The mostly PICA-related issues made PICA-to-AICA anastomosis unfeasible in all cadaveric heads included in the study.

Intervention for symptomatic vertebrobasilar disease

Disease of the vertebral (VA) and basilar arteries (BA) can lead to stroke of the posterior circulation and may warrant management strategies which differ from the anterior circulation. The mechanism and location of the disease determine its natural history and therefore affect the relative risks and benefits of the possible treatment options. Vertebrobasilar (VB) atherosclerotic disease is a source of both hemodynamic and embolic posterior circulation stroke. Advances in medical therapy have decreased the rate of stroke after initial symptomatic presentation. Antiplatelet therapy, blood pressure control, and optimization of secondary risk factors can reduce recurrent stroke risk in both intracranial and extracranial VB disease. However, symptomatic intracranial disease is still associated with a high risk of subsequent stroke, particularly those with hemodynamic compromise who represent a higher risk population. Patients with hemodynamic impairment may benefit from judicious application of endovascular and microsurgical interventions to augment blood flow. Stenting, angioplasty alone, bypass surgery, and endarterectomy, represent endovascular and surgical tools available to address medically refractory VB disease. Apart from atherosclerotic disease, dissection is another etiology of VB stroke, most frequently affecting the extracranial VA. Treatment is predominantly antithrombotic therapy although surgical or endovascular intervention can be required in rare cases of persistent embolism or hemodynamic compromise. In contrast, extrinsic compromise of the VA represents a separate extracranial pathology and is best treated with mechanistically targeted surgeries or extracranial bypass.

A successful treatment of hemifacial spasm due to anterior inferior cerebellar artery aneurysm in adolescent: a case report and literature review

OBJECTIVE

Hemifacial spasm (HFS) is usually caused by compression of the facial nerve at the root exit zone (REZ), and is extremely rare in adolescents and even rarer in aneurysm compression.

CASE REPORT

We describe symptomatic hemifacial spasm caused by a saccular aneurysm of the anterior inferior cerebellar artery (AICA) that was treated by clipping. A 17-year-old adolescent developed left hemifacial spasm that had gradually worsened over a period of 1 year before admission to our department. During the course of MVD (microvascular decompression), saccular aneurysm of AICA was accidentally found to compress the facial nerve. The cause of the facial spasm was considered to be compression of the left facial nerve by the aneurysm. Clipping the aneurysm was performed. The hemifacial spasm disappeared immediately.

CONCLUSION

Our report indicates that HFS caused by saccular aneurysm of AICA can be treated by clipping, and that aneurysms should be considered in the treatment of adolescent HFS, especially those difficult to identify on imaging examination.

In situ suturing of a post-meatal segment of the anterior inferior cerebellar artery dissected by an aneurysm: A technical note

Aneurysms originating along the peripheral portion of the anterior inferior cerebellar artery (AICA) are rare entities. As a result of the small diameter of the AICA, it is very challenging to preserve the parent artery during endovascular treatment for a peripheral AICA aneurysm. In this report, we present a rare case of aneurysm in the a2 segment of the right AICA. During surgery, the aneurysm was found to be a dissecting aneurysm. As the tissue of the aneurysm neck had a similar thickness to that of the adjacent normal vessel, interrupted suturing of the vessel was performed after partial removal and trimming of the aneurysm wall. The patient experienced an uneventful postoperative recovery. No other neurological deficit was noted. Magnetic resonance imaging three days after surgery revealed no acute ischaemia in the brainstem and cerebellum. Catheter angiography nine months later showed no recurrence of the aneurysm or stenosis of the AICA. The a2 segment of the AICA runs tortuously along the subarachnoid space of the cerebellopontine angle, which permits higher vascular mobility. In selected cases, in situ suturing or re-anastomosis could be considered for a2 segment aneurysms.