Aneurysms of the Posterior Inferior Cerebellar Artery

ABSTRACT

Aneurysms of the posterior inferior cerebellar artery are uncommon, comprising between 0.5 and 0.7% of all intracranial aneurysms and are usually tightly confined to the medulla oblongata, the anterolateral base of the skull, and the lower cranial nerves. During the period from January 1983 to December 1997, about 1,600 aneurysms were operated on the department of neurosurgery, Pusan Paik hospital, Inje University. Of these, there were 8 cases of aneurysms in the posterior inferior cerebellar artery(PICA). The average age was 43.2 years, with a range from 11 months to 56 years, and male to female ratio was equal. Presenting signs and symptoms on admission were mental deterioration and/or headache after subarachnoid hemorrhage in 7 cases and suboccipital headache due to mass effect in 1 case. The locations of these aneurysms were in the anterior-medullary segment in 4 cases, in the lateral medullary segment in one case, and telovelotonsillar segment in 3 cases. Surgical methods were as followed; unilateral suboccipital craniectomy or craniotomy(right side in 3 cases and left side in 2 cases) in lateral or park bench position was performed in 5 cases and suboccipital craniectomy in prone position was in 3 cases. Direct neck clipping were done in 5 cases, proximal ligation in 1 case, coating and trapping in 1 case each. Surgical results were good in 5 cases, fair in 2 cases, dead in a case. Although clipping of the aneurysm neck was preferable in the aneurysm of PICA, trapping was useful when neck clipping was impossible in segments distal to the choroidal arch.