Subarachnoid hemorrhage following intranasal procedures.

Two cases of subarachnoid hemorrhage complicating intranasal ethmoidectomy are presented. In both, the bleeding was initally considered coincidental to the rupture of a congenital aneurysm or an arteriovenous malformation. A direct relationship between the surgical procedure and the subarachnoid hemorrhage only became evident after extensive studies or after delayed development of CSF rhinorrhea, pneumocephalus and meningitis.