Evaluation of ostium size following endoscopic dacryocystorhinostomy as a predictive factor of outcome: A prospective study.

INTRODUCTION

Endonasal dacryocystorhinostomy (DCR) is a surgical procedure that aims to increase tear drainage to treat epiphora caused by nasolacrimal obstruction by creating a bypass through the bone between the lacrimal sac and the nasal cavity. A silicone stent is temporarily put in place for 2 months to avoid early obstruction of the rhinostomy. One of the causes of surgical failure is related to progressive stenosis of intranasal ostium, due to fibrosis and new bone growth, inducing a relapse of epiphora and/or dacryocystitis. Few studies have described changes in the size of the intranasal ostium on direct post-DCR measurement or kinetics of its shrinkage. The purpose of this study is to determine whether changes in the size of intranasal ostium might be a predictor of final functional efficacy.

MATERIALS AND METHODS

A prospective cohort of eighteen consecutive patients undergoing endonasal DCR for chronic epiphora or chronic dacryocystitis between January 2017 and April 2018 was analyzed. Eight patients who underwent bilateral DCR, and twenty-six intranasal ostia were finally analyzed. Follow-up took place every two months for 1 year, with the silicone tube removed at 2 months. Functional success was defined as absence of recurrent epiphora or dacryocystitis. Ostium size was systematically measured on photos taken during intranasal endoscopy performed every 2 months for 1 year.

RESULTS

At 2 months after endonasal DCR, 23 of the 26 ostia (88.5%) were functional, but only 19 (73.1%) of them were directly measurable. The mean horizontal diameter at 2 months was 1.44 (SD 0.61) mm, and the mean vertical diameter was 0.86 (SD 0.37) mm, which corresponded to a mean area of 10 (SD 0.84)mm. We noted a statistically significant decrease in ostium size and area between 2 and 4 months after the procedure (P -0.001), followed by a stabilization period with no statistical correlation between the size of the ostium and its final functional efficacy. At 6 months after DCR, of the 7 ostia that were not initially measurable, 3 were immediately non-functional at 2 months, 3 had a relapse of epiphora at 4 months, and 1 had a relapse of dacryocystitis at 6 months, i.e., 100% clinical failures at 6 months. The other procedures all remained functional after 1 year of follow-up.

CONCLUSION

The intranasal ostium of an endonasal DCR shrinks significantly within the 2 months after removal of the silicone tube and remains stable thereafter. There is no correlation between the size or area of intranasal ostium and its final functional efficacy. However, when the ostium is not measurable at the time of 2-month stent removal, all patients experienced a relapse of epiphora or dacryocystitis within 6 months.