Skull base anatomy and surgical safety in isolated and CHARGE-associated bilateral choanal atresia.

INTRODUCTION

Bilateral choanal atresia (BCA) is associated with a high incidence of congenital abnormalities that include skull base anomalies and defects. Surgical repair of BCA is necessary in the early neonatal period and any altered anatomy of the adjacent skull base will heighten the risk of intracranial injury. This risk may be further increased in patients with CHARGE syndrome.

OBJECTIVES

To measure surgically relevant nasal and skull base dimensions in neonates with BCA in order to determine whether any difference exists between isolated and CHARGE syndrome associated subgroups, thereby optimizing the safety of surgical repair.

METHODS

A retrospective review of medical charts and computed tomography was undertaken at a tertiary pediatric hospital of all neonates diagnosed with BCA between 2004 and 2016. Isolated and CHARGE syndrome subgroups of BCA were identified from clinical records and CT data was analyzed and compared between the two. The skull base parameters measured were choanal width, choanal height, mid-nasal skull base height and skull base slope.

RESULTS

Of the 13 patients included, 3 had CHARGE syndrome and 10 had isolated BCA. Whilst the difference in mid-nasal height approached significance for the two groups, numbers were too small for a statistical difference to be identified. The mean value for choanal width in the isolated BCA group was significantly less the largest series of normative data available in the literature for comparison (p < 0.001). No skull base anomalies were noted in either group.

CONCLUSION

While this is a small study with limited numbers, it is the first that has attempted to identify and measure the posterior nasal and skull base anatomy most pertinent to avoiding skull base injury in the surgical management of BCA.