TRIO Best Practice articles are brief, structured reviews designed to provide the busy clinician with a handy outline and reference for day-to-day clinical decision making. The ENTtoday summaries below include the Background and Best Practice sections of the original article. To view the complete Laryngoscope articles free of charge, visit Laryngoscope.com.
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June 2015Background
Nasolacrimal duct obstruction is caused by a variety of acquired and congenital etiologies. The standard treatment is dacryocystorhinostomy (DCR), with the gold standard being the external DCR. Since the advent of the nasal endoscope, the transnasal endoscopic DCR has gained popularity and has several advantages over the external approach. Some potential advantages include the avoidance of a cutaneous scar, direct access to the rhinostomy site, the ability to inspect the intranasal anatomy at the time of surgery, the avoidance of disruption of the medial canthal anatomy and its role in the function of the nasolacrimal system, shorter operative time, and shorter postoperative recovery. Despite these advantages, external DCR is often cited as having a higher success rates when compared with the endoscopic approach. This article reviews some of the evidence regarding the success rates of the external DCR and the endoscopic DCR.
Best Practice
There is a lack of prospective randomized controlled trials addressing the outcomes of endoscopic versus external DCR. Nonrandomized trials introduce bias because the patients are either self-selected or surgeon-selected; it is unclear which of the factors in making this decision may also affect surgical outcome. Since the most recent randomized controlled trial in 1998, we have gained an improved level of understanding of the endoscopic anatomy of the lacrimal sac, as well as more experience with endoscopic DCR. There are likely to be many factors that affect outcomes not evident from these studies, including increased experience, adequacy of bone removal at the rhinostomy site, use of stent, involvement of an otolaryngologist in the endoscopic procedure, and postoperative surveillance. Based on the only randomized controlled trial, external DCR provides a superior outcome to endoscopic DCR with regard to symptoms at one-year follow-up. However, there is an abundance of nonrandomized studies suggesting that endoscopic DCR with the mechanical removal of bone is a viable alternative to external DCR, with comparable outcomes (Laryngoscope. 2015;125:2-4).