Nonaneurysmal subarachnoid hemorrhage secondary to transsphenoidal surgery for pituitary adenomas.

Nonaneurysmal subarachnoid hemorrhage (SAH) is a rare and severe complication of transsphenoidal surgery for pituitary adenoma(PA). To improve recognition of this complication, we reviewed and examined 4 patients with nonaneurysmal SAH secondary to transsphenoidal surgery for PAs. Furthermore, possible causes contributed to the SAH, and the attention on preventing the occurrence of SAH is reviewed and stressed.