Objectives: Evaluate causes of surgical failure at time of revision endosco
pic sinus surgery, Study Design: Prospective review of 682 cases that had e
ndoscopic sinus surgery performed between 1991 and 1995, Methods: In all ca
ses, variables of age, sex, asthma, allergy, computed tomography stage, ass
ociated procedures, complications, and operative findings were collected. T
hose cases that had a failure after a previous endoscopic sinus procedure a
nd not an intranasal procedure or an external procedure were evaluated. Res
ults: Fifty-two patients (7.6%) were identified. The age range was 24 to 70
years. The most common cause of failure was residual air cells and adhesio
ns in the ethmoid area (30.7%), followed by maxillary sinus ostium stenosis
in 27%, frontal sinus ostium stenosis in 25%, and a separate maxillary sin
us ostium stenosis in 15% of the cases. Conclusion: Review of surgical caus
es of failure in endoscopic sinus surgery patients revealed that residual a
ir cells and stenotic maxillary or frontal sinus ostium were the most commo
n causes of failures.