Endovascular Treatment for Ruptured Distal Anterior Inferior Cerebellar Artery Aneurysm

Abstract

A 42-year-old woman presented with Hunt and Hess grade (HHG) III subarachnoid hemorrhage (SAH) caused by a ruptured left distal anterior inferior cerebellar artery (AICA) aneurysm. Computed tomography showed a thin SAH on the cerebellopontine angle cistern, and small vermian intracerebral hemorrhage and intraventricular hemorrhage in the fourth ventricle. Digital subtraction angiography revealed the aneurysm on the postmeatal segment of left distal AICA, a branching point of rostrolateral and caudomedial branch of the left distal AICA. Despite thin caliber, tortuous running course and far distal location, the AICA aneurysm was obliterated successfully with endovascular coils without compromising AICA flow. However, the patient developed left side sensorineural hearing loss postoperatively, in spite of definite patency of distal AICA on the final angiogram. She was discharged home without neurologic sequela except hearing loss and tinnitus.Endovascular treatment of distal AICA aneurysm, beyond the meatal loop, is feasible while preserving the AICA flow. However, because the cochlear hair cell is vulnerable to ischemia, unilateral hearing loss can occur, possibly caused by the temporary occlusion of AICA flow by microcatheter during endovascular treatment.

Republished: Ruptured distal AICA pseudoaneurysm presenting years after vestibular schwannoma resection and radiation

“…Occasionally, distal AICA aneurysms arise secondary to hemodynamic stress associated with cerebellar arteriovenous malformations or hemangioblastomas 9 21 30. Distal AICA aneurysms are more frequently atypical in nature (eg, dissecting) compared with aneurysms at more common locations in the intracranial circulation 11 14 16 19 25 28 31 32…”

“…Distal AICA aneurysms often present with SAH,3–5 7 9 10 12 14–16 18 24–29 31 but can also present with other symptoms of mass effect such as headache,13 19 vomiting,19 dizziness,11 ataxia,9 19 vertigo,9 hearing loss,4 10 13 19 facial paresis,4 13 trigeminal neuralgia,6 and seizures 8 19. Axial imaging with CT angiography, MRI, or MR angiography should be obtained, but occasionally the aneurysm can be occult10 or mistaken for other cerebellopontine angle or intracanalicular masses 11 13.…”

“…The most commonly used endovascular treatment is PVO with coils 7 9 14 16 26 28. Other endovascular approaches include endovascular coiling of the aneurysm with AICA preservation14 31 and PVO with nBCA,28 although it should be noted that one case of coiling without PVO resulted in incomplete aneurysm occlusion, repeat SAH, and the ultimate need for a PVO 14. A combination approach of occipital to AICA bypass plus endovascular PVO has also been used 19…”

Anterior inferior cerebellar artery aneurysms: Segments and results of surgical and endovascular managements

“…Clinical data, angiograms in articles, management techniques, and patient outcomes were reviewed for 47 collected cases in 30 published reports. [1][2][3][4][5]7,8,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][31][32][33] AICA aneurysms associated with arteriovenous malformation (AVM) and Moyamoya disease were excluded.…”

“…Anterior inferior cerebellar artery (AICA) aneurysms are so rare that published experiences are limited to case reports and small patient series. 1–33 The description of AICA aneurysms in many of these reports is imprecise. 5,10–12,31–33 Several therapeutic options exist, encompassing microsurgical and endovascular techniques.…”