A giant partially thrombosed aica aneurysm

Abstract

Aneurysms of the anteroinferior cerebellar artery (AICA) are rare, comprising far less than 1% of all intracranial aneurysms. By 1989, only 33 cases had been reported in the literature [1][2][3][4] . Subsequently, numerous case reports and small series of AICA aneurysms have been reported 1,2,[5][6][7][8][9][10][11][12][13][14][15] . Giant aneurysms of proximal portion of AICA are even more uncommon, being difficult to estimate their actual incidence. These aneurysms constitute formidable surgical challenge and a judicious preoperative planning is mandatory since surgical nuances often determined the final outcome.We present a case of giant partially thrombosed AICA aneurysm and discuss operative nuances required to minimize the morbidity associated with such surgically challenging lesions. CASEA 62 years old female presented sudden headache. At emergency room, neurological examination revealed meningismus. TC scan disclosed subarachnoid hemorrhage. Angiographic evaluation diagnosed three aneurysms at left middle cerebral artery, posterior communicating artery and a small left AICA aneurysm (Fig 1). Anterior circulation aneurysms were treated trough a left pterional approach. Postoperative course was uneventful. After two years, she returned complaining of trigeminal disestesias. Neurological examination displayed mild left facial paresis and right hemiparesis. TC scan revealed image suggestive of a thrombosed aneurysm compressing brainstem. This finding was confirmed by angiotomography and digital angiography that demonstrated giant thrombosed AICA aneurysm (Fig 2). Occlusion balloon test was carried out and patient stood asymptomatic after thirty minutes of occlusion.A right transcocclear approach was performed and the facial nerve was skeletomized and mobilized. Vertebral arteries, basilar trunk and AICA were identified and dissected (Fig 3). Temporary clips were applied proximal and distally, aneurysm sac was incised. Thrombus was removed in order to deflate the aneurysm. Two fenestrated clips were applied to the neck to preserve AI-CA (Fig 4). Two temporary clipping (thirty minutes each) were necessary to performing these maneuvers. Abdominal fat pad was harvested and used to pack the petrosal space and a catheter for lumbar drainage was inserted.Definitive deficits were deafness in the right side and right facial paresis. Postoperative angiogram disclosed adequate surgical result (Fig 5). The patient has agreed with this case publication. DISCUSSIONThe surgical exposure of AICA aneurysms is difficult due to distance of the lesions from the cranial base and their close relationship to the brainstem and lower cranial