The authors analyzed retrospectively a group of 77 adult patients (112 maxillary sinuses) treated by functional endoscopic sinus surgery (FESS) on account of chronic maxillary sinusitis. The group did not include patients with nasal polyposis. In 6 patients of this group an unilateral revision was indicated on account of persisting symptoms of inflammation in the remainder the fenestra was patent and thus the cause of the persisting inflammation was not poor ventilation nor inadequate drainage of the sinuses. In three patients a revision of FESS was performed, in another three a combined approach was used involving endoscopy and sinotomy. In three patients a mycotic infection was deetected. The diagnosis of mycotic infection was established in two patients by cultivation, in one patient histologically. In another patient the diagnosis of mycosis was very probable. He had a typical surgical finding of lumpy dark secretion in the maxillary sinus and a CT image corresponding to mycotic sinusitis. In that patient the mycosis was not confirmed by cultivation nor by histological examination. In two patients mycotic infections was not suspected.

        Key words: functional endoscopic sinus surgery, revision, maxillary sinusitis, fungal sinusitis, mycetoma