Fig. 3.

( A ) Transnasal rigid endoscopic view of the left middle meatus with instrument (*) against lateral nasal sidewall anterior to U. ( B ) Flexible endoscope passed through choana to obtain retrograde view visualizing the same instrument and the medial aspect of the MT. ( C ) Combined image with the retrograde view assist shown as a picture-in-picture window, allowing the surgeon to look behind uncinate under the E toward the maxillary ostium. The tips of the R and F endoscopes are visible within each image. E, ethmoid bulla; F, flexible; MT, middle turbinate; R, rigid; U, uncinate.