Dacryocystorhinostomy

Abstract

Obstruction of the nasolacrimal duct (NLDO) may be primary, in which case the cause is unknown, but consists of either a functional or a physical blockage to the path tears take in drainage, or acquired, in which case the drainage is blocked through infective, inflammatory or traumatic (fracture affecting facial bones) processes, or surgical interventions (such as those affecting the sinus, or maxillofacial oncological surgery). Acquired NLDO is the number one reason for epiphora. The lacrimal system can be obstructed anywhere along the entirety of its length. Obstruction is classified as pre-sac (affecting the common canaliculus), sac related, or post-sac, according to the anatomical location of the obstruction. Traditionally, acquired NLDO is treated by external dacryocystorhinostomy (DCR), but this procedure is reported to fail in 5-15% of cases. Advances in endonasal endoscopy for diagnostic and therapeutic use have enabled the development of endoscopic DCR (EDCR) as an alternative treatment for NLDO. As the technique is associated with a higher rate of success and less attendant morbidity than external DCR, EDCR has, in many cases, replaced the older technique both for initial treatment and where surgical revision is necessary. Use of the endoscope has led to greater surgical access to every part of the nasal cavity. Due to the possibility of obtaining angled views and the small-calibre design of the endoscope, the interior of the nose can be visualised in excellent detail and the lacrimal sac located and opened relatively easily.