Endoscopic Endonasal Dacryocystorhinostomy with Ostial Stent Intubation Following Nasolacrimal Duct Stent Incarceration

We read with great interest the study by Wang et al. describing a novel ostial stent for using in dacryocystorhinostomy (DCR) surgery.1 In our clinic, we have also been conducting studies on new stents in order to increase the success rate of DCR surgery. As it is known, the success rate of DCR surgery is associated with new ostium survival. Therefore, various ostial implants (lacrimal silicone tube, T-tube ostial stent) or anti-fibrotic agents (mitomycin C, 5-fluorouracil) have been used to maintain the patency of the neo-ostium.2–7 Since a long time, silicone tube intubation is applied in DCR surgery to prevent the closure of ostium. However, it bears several complication risks including infection, granulomatous reactions, conjunctiva and punctum injury, intranasal discomfort, prolapse, extrusion, conjunctival irritation and poor cosmesis.8 It is also considered that the silicone adversely affects the physiological pump functioning in the lacrimal drainage system.9 These other applications also have different advantages and disadvantages. Therefore, it is still an ongoing quest for the ideal treatment for nasolacrimal duct obstruction.

In this current article, the main focus was to compare the bicanalicular silicone implantation with local novel ostial stent application in cases for which the DCR surgery failed. All cases were chronic dacryocystitis patients suffering sustained inflammation due to previously implanted nasolacrimal duct stent (NDS). Both the already-present inflammation and the application of this novel silicone ostial stent aggravate further inflammation and granulation. The intranasal part of this novel ostial stent is designed as a wide (18–20 mm) fan-like element to help the scar tissue re-extend and close the ostium; however, this again enhances risks of inflammation and granulation. Silicone-induced granulation formation is one of the major causes of surgical failure in DCR surgery with silicone tube/stent intubation. Therefore, in this study, it would have been a more appropriate approach to apply first an additional treatment to alleviate the inflammation following NDS removal, and consequently implant the stent as a second step. It seems quite difficult to discover an ideal stent material which is both biocompatible and functional in DCR surgery.

Silicone is an inherently soft material and thus, there is the possibility that silicone stent could move out from the implanted ostium. Hence, it would be difficult to stabilize the stent, which is implanted to the intra-ostium drilled to the bone, especially during primary DCR surgery. On the other hand, it would be easier and less traumatic to apply the stent in a special injecting system, since it is difficult to implant stent with a pen in a tight nasal cavity for some patients. Lastly, we also conclude that the intraoperative application of an additional antifibrotic agent (such as mitomycin C) would be beneficial, especially for patients with significant inflammation and fibrous tissue formation, such as those mentioned in this study.

DECLARATION OF INTEREST

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.