Posterior fontanelle approach for uncinectomy and middle meatal antrostomy in endoscopic sinus surgery.

INTRODUCTION The concept of functional endoscopic sinus surgery (FESS) was established by Stammberger in 1986. When FESS is performed, the first encountered anatomical structure in the sinonasal tract is the uncinate process. Resection of the uncinate process is one of the important procedures in FESS, because the natural ostium of the maxillary sinus is located behind this process in most patients, and the maxillary, frontal, and anterior ethmoid sinuses can be entered under good visualization after its complete removal. Surgically, two methods are most widely used for uncinectomy: the classical uncinectomy technique described by Stammberger and the swing-door technique described by Wormald and McDonogh. Although the incidence is low, some complications occur with these two methods. The most common complication of the classical method is orbital penetration, because the uncinate process is incised in the anteroposterior direction without knowledge about the depth of the infundibulum. In particular, the risk may increase when the uncinate process is lateralized and the infundibulum is contracted. With regard to the swing-door technique, nasolacrimal duct injury is the most common complication. The risk may increase when the uncinate process is short and small. In addition, with both techniques, beginners may find it difficult to identify the natural ostium of the maxillary sinus if it is situated in a difficult location. In general, uncinectomy is followed by middle meatal antrostomy, which involves widening of the natural ostium mainly toward the posterior fontanelle. The posterior fontanelle of the maxillary sinus is located between the tails of the middle and inferior turbinate, behind the hiatus semilunaris and under the ethmoid bulla. It is mainly composed of soft tissue as a part of the medial wall of the maxillary sinus. Because it can be easily identified medial to the middle turbinate, we hypothesized that antrostomy through the posterior fontanelle followed by uncinectomy would be a safe and effective alternative to conventional uncinectomy and middle meatal antrostomy. The present study aims to introduce this new surgical approach.