The GNC can be placed either by external or endonasal approaches [5, 6]. With the endonasal approach, once intubation is performed, the tubes are placed within the lumen of the catheter. The catheter is then advanced in the nostril with bayonet forceps until the proximal collar is in the lacrimal sac fossa. If an external approach is used, the catheter is placed into the rhinostomy without suturing of flaps.

The tubes and catheter may be removed in the office setting after remaining in place for 6 months. After removing the intubation tube, the catheter is grasped from the intranasal portion and removed from the nostril. Sedation may be needed for removal in pediatric patients, but topical anesthesia is usually sufficient for removal in adults.

The Modified Rains Stent (MRS) is created from a silicone Rains frontal sinus stent. The top of the bulbous end is cut with scissors so the ribs are separated, but remain in a bulb shape to prevent dislodgment. The tubular portion is trimmed to a length that avoids contact with nasal septum (Fig. 21.2). Once in place, the bulb collects tears and directs them through the tube into the nasal cavity.

The MRS is placed using an external approach. The anterior portion of the lacrimal sac is opened, and a small hole is created in the posterior aspect of the sac. Once a 4 mm diameter ostium is created, the device is placed in the lacrimal sac and the tubular end is placed through the ostium. The anterior lacrimal sac incision is closed and the overlying surgical incision site is closed in normal fashion.

The MRS has been left in place for extended periods of time without complication. Regular endoscopic exams to look for possible mucosal erosion and debridement of the tube may be required.

Previous reported success rates for primary and secondary DCR are 90–95 % [8, 9]. The GNC has been used in multiple studies for primary and secondary DCR with 100 % patency at 3 years and 98 % patency at 2.5 years respectively [6] without pyogenic granuloma formation in any cases.

The use of the GNC may also be indicated in patients with significant sinonasal disease or congenital nasolacrimal duct obstruction associated with craniofacial abnormalities, as these cases tend to develop cicatricial stenosis at higher rates than cases with relatively normal nasal mucosa.

The Modified Rains Stent, a potentially permanent silicone stent, has shown promise in these difficult cases with 8 of 9 patients asymptomatic at 2.5 years [7].

The GNC and MRS have been successful in maintaining ostium patency following DCR. Once the technique is learned, insertion of the GNC has more successful outcomes and reduces operative time versus suturing flaps. The biocompatibility and ease of in-office removal further supports the use of the GNC. Furthermore the GNC and the MRS can be useful in cases with significant sinonasal disease or congenital nasolacrimal duct obstruction due to craniofacial abnormalities; however, in these difficult cases, the MRS has shown high success rates.