The Effect of Maxillary Sinus Antrostomy Size on Xenon Ventilation in the Sheep Model

OBJECTIVE: A major goal of maxillary antrostomy is to increase sinus ventilation. Limited data exist regarding the effect of maxillary antrostomy size on sinus ventilation. We sought to quantify the effect of uncinectomy, small antrostomy, and large antrostomy on maxillary sinus ventilation using xenon-enhanced CT in the sheep model.

MATERIALS, STUDY DESIGN, AND METHODS: A xe-non-oxygen-air mixture was delivered to 8 fresh cadaveric sheep heads while repeated CT scans were performed through the maxillary sinuses. Baseline and postoperative studies were performed after an endoscopic uncinectomy, small antrostomy, or large antrostomy was created. Images were analyzed to measure the density of the xenon gas in the maxillary sinus as a function of time, generating a time constant.

RESULTS: The time constants for both small antrostomy and large antrostomy were significantly different compared to baseline (P = 0.003 for both). The time constant comparison between small antrostomy and large antrostomy was not significant (P = 0.948).

CONCLUSIONS: A small antrostomy produces a statistically significant increase in maxillary sinus ventilation over baseline. No significant further ventilation increase is obtained by creating a large antrostomy in the sheep model. This lends credence to the use of small antrostomies to improve maxillary sinus ventilation in human sinus surgery.