Surgical distance to the sphenoid ostium: a comparison of healthy patients and patients with cystic fibrosis.

OBJECTIVES To establish and compare the distance and angle from the limen nasi to the sphenoid ostium in pediatric patients with normal sinonasal anatomy vs pediatric patients with cystic fibrosis (CF). DESIGN Retrospective review of computed tomographic images. SETTING Tertiary university-based medical center. PARTICIPANTS Patients (newborn to age 20 years) with normal sinonasal anatomy (n = 117) or CF (n = 15). MAIN OUTCOME MEASURES We used a fourth-degree polynomial to curve-fit the distance to the sphenoid ostium vs age for patients with normal sinonasal anatomy, producing a coefficient of determination (R(2)) of 82%. With this regression curve, we produced a normative distance equation and a normative distance graph using age to predict the distance (95% confidence interval). We validated the normative distance curve fit among 30 new pediatric patients. RESULTS No significant difference in the distance to the sphenoid ostium was found between healthy patients and patients with CF. There was no correlation between age and angle in either patient group. The mean (SD) angle was statistically different between healthy patients (37.5 degrees [7.5 degrees]) and patients with CF (41.4 degrees [7.4 degrees]). CONCLUSIONS Using a normative distance graph and the mean angle, surgeons performing pediatric endoscopic sinus surgery can predict the distance to the sphenoid ostium for healthy patients and for patients with CF. These findings may decrease complications of endoscopic sinus surgery among the pediatric population.