Pushed monocanalicular intubation: a preliminary report

To study the behavior of a "pushed" monocanalicular stent by means of nasal endoscopy.

Four children (six affected sides) with congenital nasolacrimal duct obstruction were treated with monocanalicular intubation with an anchoring plug. The children's mean age at the time of the operation was 33 months (range, 30-37 months). The procedure began with probing in order to verify (a) dacryostenosis (simple or extensive nasolacrimal duct impatency) and (b) the metal-to-metal contact in the lower nasal meatus. The stent was similar to a Monoka(TM), but the guide (a malleable stainless steel probe) is located inside the silicone stent rather than projecting from it. The silicone's total length is 40 mm and the external diameter 0.96 mm. Simultaneously, the guide acts to catheterize the nasolacrimal duct by pushing the silicone through the upper and lower parts of the outflow system. The guide is removed via a punctal approach. This mode of intubation dispenses with the nasal recovery step. Nasal endoscopy was used to monitor (a) the position of the stent in the lower nasal meatus (free or submucosal), (b) mucosal damage and bleeding, and (c) the behavior of the silicone tube during removal of the guide.

Because of the complexity of nasolacrimal ducts, two of the six sides were treated with the classical Monoka intubation method of pulling the silicone tubing out from the nasal exit of the duct (the pull technique). The pushed intubation method was used for the four simple nasolacrimal stenoses, with no problems whatsoever. In all four cases, endoscopic examination showed (a) no submucosal tunneling (false passage), (b) no noteworthy mucosal damage, and (c) no retraction (bunch-up) of the silicone tube during the metal guide removal. No particular complications were reported during the procedure or the intubation period, which lasted an average of 3 weeks. The stents were removed in the consulting room. Tearing ceased during the 1(st) week in two cases, during the intubation period. Tearing persisted throughout the intubation period in the other two cases, but ceased during the week following stent removal. The follow-up lasted 2 months.

The pushed procedure simplifies monocanalicular nasal intubation. Its indications remain to be determined.