Meningitis after trans-sphenoidal excision of pituitary tumours.

Between 1974 and 1986, eleven of 114 patients undergoing trans-sphenoidal removal of pituitary tumours developed meningitis despite prophylaxis, usually with chloramphenicol. Nine patients had cerebrospinal fluid rhinorrhoea and one died. A variety of pathogens was isolated, including enterobacteria, and four of the eleven were resistant to the antibiotics given as prophylaxis. Enterobacterial meningitis was always associated with infection of the sphenoidal sinus involving the muscle graft or nasal pack (five cases), and removal of the muscle graft was necessary in three cases despite the use of appropriate antibiotics.