Aneurysms arising from the cortical segment of the superior cerebellar artery--two case reports.

Two unusual cases of partially thrombosed or fusiform type aneurysm on the cortical segment of the superior cerebellar artery (SCA) with subarachnoid hemorrhage are described. A 71-year-old female had a partially thrombosed, multi-lobular aneurysm located at the marginal branch of the SCA. This aneurysm was successfully clipped and wrapped via a subtemporal transtentorial approach in the acute stage. A 52-year-old female had an atherosclerotic fusiform aneurysm located at the distal portion of the hemispheric branch of the SCA. This aneurysm was successfully trapped using an infratentorial supracerebellar approach in the acute stage. Both patients were discharged without neurological deficits. The subtemporal transtentorial or lateral suboccipital approach for the proximal cortical segment, and the infratentorial supracerebellar approach for the distal cortical segment of the SCA are recommended for surgical treatment of these aneurysms.