Endonasal dacryocystorhinostomy - A report by the American Academy of Ophthalmology

Objective: This document describes endonasal dacryocystorhinostomy (DCR) an d examines the evidence to answer key questions about the effectiveness of the procedure compared with external DCR; the relative indications, contrai ndications, advantages, and limitations of the procedure; and patient selec tion, surgical technique, postoperative care, and complications. Methods: A literature search conducted for the years 1968 to 2000 retrieved 93 citations. The panel members reviewed 71 of these articles and selected 64 for the panel methodologist to review and rate according to the strengt h of evidence. A level I rating is assigned to properly conducted, well-des igned, randomized clinical trials; a level II rating is assigned to well-de signed cohort and case-control studies; and a level III rating is assigned to case series and poorly designed prospective and retrospective studies, i ncluding case-control studies. Results: The published literature includes two reports that describe clinic al trials comparing endonasal with external DCR with a 1-year follow-up. Th e success rate was 91% for the external DCR group in both reports and 63% a nd 75% for the endonasal DCR groups, defined by patency to irrigation. A lo ngitudinal cohort study included a control group of age-matched external DC R patients who were compared with a study group of endonasal DCR patients. The reported success rate at 9 months following surgery for the endonasal c ohort was 90% and was not statistically significantly different from the 94 % success rate noted in the external DCR control group. Remaining data on r eported success rates of primary and revision endonasal DCR were obtained f rom a collection of uncontrolled observational case studies with varying pe riods of follow-up and success rates ranging from 59% to 100%. Conclusions: It is difficult to make definite evidence-based determinations about the relative efficacy of endonasal and external DCR because of the d eficiencies in the reported literature. Based on level III evidence, the av ailable data suggest that endonasal DCR may be a viable option for the corr ection of acquired nasolacrimal duct obstruction and complex forms of conge nital dacryostenosis in selected patients. This procedure may be indicated on a primary basis or as revisional surgery following failed external or en donasal DCR. Some studies comparing endonasal DCR with external DCR suggest ed lower success rates in the endonasal group; other studies yielded succes s rates comparable with or exceeding those of external surgery. Reported co mplications of endonasal DCR do not generally appear to be greater in frequ ency or magnitude than those associated with external DCR. Disadvantages of endonasal DCR include the preferred use of general anesthesia by many surg eons, the high cost of expensive equipment and instrumentation, and the rel atively steep learning curve for this procedure. Depending on the preferenc e of the surgeon, more postoperative care may be required for patients unde rgoing endonasal DCR than external DCR. Both the advantages and the limitat ions of endonasal DCR relative to external DCR should be carefully discusse d with patients who are contemplating endonasal surgery. (C) 2001 by the Am erican Academy of Ophthalmology.