Effects of long-term induced ostial obstruction in the rabbit maxillary sinus.

One of the widely proposed theories for mucocele formation is sinus ostial obstruction. Accordingly, this study was undertaken to investigate the long-term effects of ostial obstruction in the rabbit maxillary sinus and its potential role in the pathogenesis of mucoceles. Maxillary sinus ostial obstruction was induced on one side in eight Pasteurella-free White New Zealand rabbits using Histoacryl. The rabbits were housed in a Pasteurella-free zone for 24 weeks. At re-exploration, only three of the eight maxillary sinuses where ostial obstruction was induced showed pressure recording consistent with ostial obstruction. Mucociliary clearance activity was assessed using India ink. Swabs for culture were taken from the infected maxillary sinuses. Mucosal specimens for histopathological examination were harvested from one of the maxillary sinuses with obstructed ostium as well as from another sinus with nonobstructed ostium. The three maxillary sinuses with obstructed ostia showed gross evidence of infection and deranged mucociliary clearance, but no mucocele formation. Based on the findings of this study it is concluded that long-term ostial obstruction indeed plays a role in the pathogenesis of chronic sinusitis, but it did not induce mucocele formation in the rabbit maxillary sinus.