Histological evaluation of maxillary sinus mucosa after functional endoscopic sinus surgery.

Background: This study was performed to evaluate the histological changes of the maxillary sinus mucosa of patients with chronic rhinosinusitis (CRS) after functional endoscopic sinus surgery (FESS).

Methods: In a cohort study, biopsy specimens were collected from the maxillary sinus of patients submitted for FESS. One year after surgery, patients were clinically reassessed. Patients showing recurrence of disease (group 1) required a revision surgery, through which a second biopsy specimen was collected. Patients showing a favorable clinical response (group 2) were submitted to an outpatient maxillary biopsy through the previous opened middle meatus antrostomy. Biopsy material from four cadavers was used as control. The histological and electron microscope findings were analyzed.

Results: At the initial surgery, patients presented many histopathological alterations, such as an inflammatory process infiltrating the submucosa, atypical respiratory epithelium with an important increase in goblet cells, metaplasia, or mixed epithelium. Group 1 patients persisted with the same alterations 1 year later, but ciliary dysmorphy was more accentuated. Group 2 patients presented a predominantly pseudostratified epithelium, but some areas contained an increased number of goblet cells and a reduction in the number of ciliated cells.

Conclusion: Recovery of the maxillary sinus mucosa of patients with CRS, observed by electron and light microscopy, was incomplete 1 year after endoscopic surgery, even in nonsymptomatic patients; nevertheless, these alterations were more important in symptomatic patients than in asymptomatic patients.