Possibility of Pseudo-Obstruction in Lacrimal Canalicular Obstruction Diagnosed with Dacryocystography

Abstract

<b><i>Introduction:</i></b> Endoscopic dacryocystorhinostomy (DCR) is the treatment of choice for patients with lacrimal drainage system obstruction. Dacryocystography (DCG) is one of the most common preoperative studies and considered as a useful test demonstrating the anatomy of lacrimal drainage systems. <b><i>Objective:</i></b> This study was designed to evaluate the diagnostic efficacy of DCG for canalicular obstruction and to compare surgical outcomes between true-obstruction versus pseudo-obstruction diagnosed with DCG. <b><i>Methods:</i></b> A retrospective study was performed on 45 consecutive patients with lacrimal canalicular obstruction who had underwent endoscopic DCR with silicone tube insertion from January 2009 to December 2014 at a single tertiary hospital. A review of medical records included demographic data, preoperative symptoms and signs, results of intraoperative canalicular probing, and surgical outcomes including the postoperative symptom improvement and endoscopic finding. <b><i>Results:</i></b> Of 45 patients, 34 patients (75.6%) had true-canalicular obstructions and 11 patients (24.4%) had pseudo-canalicular obstructions. The success rate of endoscopic DCR was 50% (17 of 34) in cases with true-canalicular obstruction while 90.9% (10 of 11) in pseudo-canalicular obstruction (<i>p</i> value <0.05). No intraoperative or postoperative complications including sinusitis or synechia were found. <b><i>Conclusions:</i></b> About a quarter of lacrimal canalicular obstruction cases diagnosed with DCG seem to be pseudo-obstruction. The success rate of endoscopic DCR in pseudo-canalicular obstruction is similar to that of saccal and nasolacrimal ductal obstruction.

Soft stop on syringing and probing may have a high false-positive rate in diagnosing pre-sac obstruction

“…On the other hand, there was a single case of false-positive common canalicular stenosis on DCG. CLS-MFs may appear as an area of common canalicular stenosis on DCG [ 26 ], and distal kinking of the canaliculus may manifest as a pseudo-obstruction [ 27 ]. Taken together, these results suggest that there may be value in confirming equivocal syringing/probing findings on DCG.…”