Iatrogenic Bony NLD Dehiscence

Abstract

The course of nasolacrimal duct is directed downward, posterior, and lateral, and this is very important on the lateral wall topography. Nasolacrimal duct injury has been reported as a consequence of numerous surgical procedures including uncinectomy, endoscopic sinus surgery, frontal sinusotomy, maxillary osteotomy, external or endoscopic medial maxillectomy, rhinoplasty, inferior turbinectomy, and maxillofacial trauma repair [1–3]. The NLD passes anterior to hiatus semilunaris in the wall of the middle meatus, and in here the distance between NLD and maxillary ostium varies from 3 to 6 mm. This close anatomical relationship predisposes it to iatrogenic injury during uncinectomy and middle meatal antrostomy. The incidence of dehiscence reported varies from 3.6 to 15% [1–3]. It is also important to note that preoperative or preexisting dehiscence has also been reported. It is equally important to distinguish postoperative reactive osteitis form a frank NLD trauma [1]. Otolaryngologists themselves should become familiar with the radiological course of the NLD and variants in its bony anatomy in the hope of predicting patients at risk of iatrogenic injury. Other factors that may reduce the incidence of injury during FESS include clear visualization of the surgical field, appreciation of regional anatomy, controlled enlargement of maxillary ostium, posteroinferior direction of back biter punch, and avoiding bone engagement anterior to uncinate process. NLD injury following FESS is uncommon but does occur, and so all patients should be consented appropriately preoperatively.