Canalicular Coronary Stent Recanalization: First Experience in Human Patients, Surgical Techniques, and Outcomes.

PURPOSE: To investigate the feasibility of implanting a drug-eluting cobalt-chromium alloy coronary stent in patients with extensive canalicular obstructions.

METHODS: The pilot study was carried out in 4 canaliculi of 4 patients with extensive canalicular obstructions in a setting of earlier failed dacryocystorhinostomy. All patients underwent preoperative dacryoendoscopy to characterize the canalicular obstruction. This was followed by full-length canalicular trephination and balloon dacryoplasty along with a revision dacryocystorhinostomy. Sirolimus-eluting coronary stents of 2 mm in diameter (when fully expanded) and 12 mm in length, mounted on balloon catheters, were used. The balloon catheters were introduced into the canaliculi under endoscopy guidance. The stents were delivered following dilatation of the balloon to 12 atmospheres and secured in a locked (spring-out) position. The balloon was then deflated, securely removed, and the stent position was reconfirmed with a dacryoendoscopy. Postoperative monitoring of the implanted stent was performed using dacryoendoscopy, nasal endoscopy, CT scans, and MRI imaging to assess its stability, outcomes, and complications.

RESULTS: The drug-eluting cobalt-chromium alloy coronary stents could be delivered and secured at a desired position within the canaliculi. The trephined canaliculi were uniformly dilated 360 degrees with a wide and uniform lumen. Intraoperatively, the edges and intervening patches of the freshly trephined canalicular lumen were uniformly distributed in spaces between the stent rings without any influence on the already expanded lumen. CT-dacryocystography (DCG) and MRI provided additional information on the stent position, angulation, and dye conductance through the stent. At 6 weeks, 2 of the canaliculi reoccluded, 1 partially reoccluded, and 1 was patent. The postoperative course provided several new learnings that would help further modify the procedure. The surgical learning curve is shallow if the surgeon is adept with canalicular trephination and balloon dacryoplasty techniques.

CONCLUSION: Drug-eluting cobalt-chromium alloy coronary stents can be precisely deployed and secured within a well-trephined canaliculus. The study is the first to demonstrate the surgical technique of canalicular coronary stent recanalization in human patients with canalicular obstructions. While there were some frustrating failures, this pilot study, nevertheless, lays the foundations of prophylactic or therapeutic techniques that have the potential to maintain canalicular patency in a wide range of canalicular disorders.