Management of anterior inferior cerebellar artery aneurysms: an illustrative case and review of literature

Abstract

<jats:p>Aneurysms of the anterior inferior cerebellar artery (AICA) are relatively rare among intracranial aneurysms. They can occur in 1 of 3 regions of the AICA: 1) craniocaudal (high or low riding), 2) mediolateral-premeatal (proximal), and 3) meatal-postmeatal (distal). The management strategies for treatment differ according to the location and configuration of the aneurysm. The existing body of neurosurgical literature contains articles published on aneurysms arising from the AICA near the basilar artery (BA), intracanalicular/meatal aneurysms, and distal AICA. Several therapeutic options exist, encompassing microsurgical and endovascular techniques. The authors describe a case of treatment involving a large BA-AICA aneurysm approached via exposure of the presigmoid dura using a retromastoid suboccipital craniectomy and partial petrosectomy. Treatment of these lesions requires detailed knowledge of the anatomy, and an anatomical overview of the AICA with its arterial loops and significant branches is presented, including a discussion of the internal auditory (labyrinthine) artery, recurrent perforating arteries, subarcuate artery, and cerebellosubarcuate artery. The authors discuss the various surgical approaches (retromastoid, far lateral, subtemporal, and transclival) with appropriate illustrations, citing the advantages and disadvantages in accessing these AICA lesions in relation to these approaches. The complications of these different surgical techniques and possible clinical effects of parent artery occlusion during AICA surgery are highlighted.</jats:p>

Petrosal approaches to posterior circulation aneurysms

“…14,52 In addition, most patients treated with complete petrosectomy suffered long-term facial nerve palsies. 6,18 These results reinforce the intuitive point that labyrinth-sacrificing approaches are less germane in cerebrovascular applications of the petrosal approaches, given the near-ubiquitous presence of serviceable preoperative hearing. Originally conceptualized by Hakuba, 21 a combined posterior petrosal and anterior petrosal approach may be used instead.…”

“…55 In our review of the literature, we found 34 cases of posterior circulation aneurysms treated via the standard retrolabyrinthine posterior petrosal approach reported in 14 studies over the course of 2 decades (Table 3). 3,6,11,12,14,22,24,32,40,42,43,50,54,56 All aneurysms were completely occluded. In addition, although early morbidity was high (62%; 41% in the form of cranial nerve deficits), it was often transient.…”

“…50 Sparse reports of extended posterior petrosal approaches to posterior circulation aneurysms, sacrificing all or part of the labyrinth, are present in the literature. 5,6,8,14,18,51,52,57 Approach-related morbidity in the form of cranial nerve deficits was seen in nearly all cases, even in cases of partial labyrinthectomy. 14,52 In addition, most patients treated with complete petrosectomy suffered long-term facial nerve palsies.…”

“…This summary excludes studies employing transsigmoid infratentorial approaches 12,17,46 and those with approaches sacrificing all or part of the labyrinth. 5,6,8,14,18,51,52,57 Anterior Petrosal Approach An extension of the middle fossa approach, 27 the anterior petrosal approach, originally described by Bochenek and Kukwa in 1975, 7 was initially applied to basilar aneurysms by Kawase in 1985. 31 Prior to the "Kawase approach," low-lying basilar apex and upper basilar trunk aneurysms would often be exposed via a subtemporaltranstentorial approach with added traction placed on the temporal lobe.…”

Management of Anterior Inferior Cerebellar Artery Aneurysms: Endovascular Treatment and Clinical Outcome

“…[9][10][11][12][13][14][15][16][17][18][19][20][21] Although various surgical approaches have been introduced to access these aneurysms, surgical treatment is often limited due to the complexity of the adjacent neurovascular structure, the presence of brain stem perforators, the narrow and deep surgical field, and the necessity of an experienced surgeon.…”