Nasolacrimal Duct Coronary Stent Recanalization (NCR): First Cadaver Experience and Its Potential as an Alternative to DCR

Purpose:To investigate the feasibility of implanting a drug-eluting cobalt-chromium alloy coronary stent in the nasolacrimal ducts (NLDs) of human cadavers.Methods:The pilot study was carried out in 5 NLDs of 4 adult human cadavers. Sirolimus-eluting coronary stents of 2 mm in width and lengths of 8 and 12 mm, which were mounted on balloon catheters, were used. Following dilatation of the NLDs, the balloon catheters were introduced into the NLDs under direct endoscopy guidance. The stents were delivered following dilatation of the balloon to 12 ATMs and secured in a locked (spring out) position. The balloon is then deflated and securely extubated. The dacryoendoscopy confirmed the stent position. The lacrimal system was then dissected to assess several key parameters like the uniformity of the NLD expansion, anatomical interactions of the NLD mucosa with the stent rings and struts, integrity of the soft and bony NLD, stent movement on mechanical push and pull, and ease of manual removal.Results:The cobalt-chromium alloy coronary stents could be delivered with ease and secured in the cadaveric NLDs. Its position was confirmed by a dacryoendoscopy and later by the direct NLD dissection. The NLD was uniformly dilated 360 degrees with a wide and uniform lumen. NLD mucosa was noted to be uniformly distributed in spaces between the stent rings without influencing the expanded lumen. Following the lacrimal sac's dissection, the NLD stent showed significant resistance to downward movement but could be easily retrieved with forceps. The 12-mm stents could reach the near total length of the NLD with good luminal expansion. The integrity of the bony and soft-tissue NLD was maintained. The learning curve is shallow if the surgeon is adept with the techniques of balloon dacryoplasty.Conclusion:Drug-eluting cobalt-chromium alloy coronary stents can be precisely deployed and secured within the human NLDs. The study is the first of its kind to demonstrate the technique of NLD coronary stent recanalization in human cadavers. It is a step forward in the journey to evaluate their use in patients with primary acquired NLD obstructions and other NLD disorders. Nasolacrimal duct coronary stent recanalization (NCR) appears to be a promising alternative to DCR in cadaveric studies. Further human in-vivo trials would help to assess the indications and limitations of this procedure.