Recanalization of the Obstructed Nasolacrimal Duct System

IN this and other recent issues of the Journal, Lee et al (1), Lanciego et al (2), and Pabon et al (3) published studies detailing their efforts to reestablish lacrimal drainage through obstructed nasolacrimal ducts (NLD) (and obstructed canaliculi in the paper by Lee et al [1]) with use of minimally invasive techniques. Although the obstructed NLDs of children respond well to methods such as balloon catheter dilation (dacryocystoplasty), recanalization of the NLD in adults with acquired NLD obstruction has proven to be much more difficult (4–7). Repeated probing procedures with a variety of different sized probes were used in the 19th and early 20th centuries (7). Toti (8) introduced external dacryocystorhinostomy (DCR) in Italy in 1904, and modifications by Dupuy-Dutemps (9) and Mosher (10) over the ensuing 20 years led to the modern DCR procedure with success rates of 90% or higher. Although external DCR has a high success rate, the potential for bowstring scars, hemorrhage, sinusitis, and prolonged recovery time has caused physicians to look for less invasive ways of treating NLD obstruction (11). New techniques of lacrimal surgery have been aided by the development of endoscopes that allow detailed visualization of relevant intranasal anatomy. Transnasal and transcanalicular laser DCR have been described by several authors. Patency rates have varied widely among different series, ranging from 50% to 100% (11–14). Expensive equipment is required, and the procedure may be technically challenging (11–16). For these reasons, laser DCR has lost favor (15). Balloon catheter DCR has less associated morbidity than external DCR, does not require an incision, is technically simple, and does not use expensive equipment (17). I believe that balloon catheter DCR, aided by effective stents, will play a significant future role in the treatment of acquired NLD obstruction. Recanalization of the obstructed NLD is appealing in that it restores the integrity of the natural lacrimal drainage system, avoids the necessity of making new openings through the medial lacrimal sac wall, lacrimal fossa, and lateral nasal wall, and eliminates the need for anterior middle turbinectomy, all of which may be required in endoscopic DCR procedures (11–18). Therefore, recanalization of the NLD should be the least invasive of all these techniques. Acquired NLD obstruction may be caused by trauma, surgical procedures, sarcoidosis, Wegener granulomatosis, or polyps, but the etiology is not known in the majority of cases (19–22). Linberg and McCormick (23) found varying degrees of inflammation and fibrosis of the NLD in patients with primary acquired NLD obstruction. However, all but two of their patients had dacryocystitis, making it unclear whether the inflammation was causative or solely a result of infection. Primary acquired NLD obstruction is more common in women than men by a multiple of 1.7–7, depending on the study, and peaks in the 51–70-year age group (24–27). Blacks rarely have primary acquired NLD obstruction (7). Differences in diameter of the bony nasolacrimal canal have been suggested as an explanation for these sex and ethnic differences (7,27– 29). This hypothesis was disputed by Phillips (30), who found no difference in diameter of the bony nasolacrimal canal between patients with NLD obstruction and those without it. This lack of understanding of the pathophysiology of primary acquired NLD obstruction has hindered efforts to recanalize the NLD. In the April issue of the Journal, Lee et al (1) described their results of balloon catheter dacryocystoplasty in 350 patients. Fifteen of 16 lacrimal systems with congenital NLD obstruction had a successful outcome, consistent with the high success rate found previously (4). Dacryocystoplasty with a 3-, 4-, or 5-mm balloon was performed in 155 lacrimal systems with NLD or lacrimal sac obstruction. The initial success rates were 41.1% in obstructions of the junction of the sac and duct, 51.1% in obstructions of the lacrimal sac, and 82.2% in obstructions of the NLD. Canalicular obstruction must be evaluated separately, because it is genFrom the Department of Ophthalmology, Orbital and Ophthalmic Plastic Surgery Division, Jules Stein Eye Institute and Department of Ophthalmology, University of California Los Angeles School of Medicine, Los Angeles, California. Address correspondence to B.B.B., 5363 Balboa Blvd., Suite 246, Encino, CA 91316; E-mail: brisbeee@aol.com The author has disclosed the existence of a potential conflict of interest.