A standard skin incision and soft tissue dissection are performed to expose the lacrimal sac. A Bowman’s lacrimal probe is placed into both the inferior and superior canaliculi, and an incision is made through existing scar and mucosa of the rhinostomy, creating a large anterior nasal flap. In most cases, the bony rhinostomy, sac, and/or duct are found to have been insufficiently opened to allow for an adequate rhinostomy. After the creation of an adequate bony osteum of at least 10–20 mm, the lacrimal and mucosal flaps are sutured. Silicone tubes are inserted if there is any canalicular pathology or if the sac is small, scarred, or inflamed. The tubes are removed 3–6 months postoperatively.

Mucoperiosteal flap surgery is performed under endoscopic visualization, in the projection of the lacrimal fossa to obtain a flap incision that is slightly more anterior over the frontal process of the maxilla. This mucosal incision allows the correct surgical plane to be established for the dissection of the mucosal flap. The flap is undermined and resected, and the medial bone wall of the lacrimal sac or its remnant is removed by drilling or using a Kerrison rongeur until complete sac exposure is obtained. The lacrimal sac is located by inserting a stent into the lacrimal canaliculi and is opened along its full vertical length using a sickle knife. Silicone tubes are inserted into the nasal cavity via the superior and inferior puncta, and are removed 3–6 months postoperatively (Fig. 18.2).

The reason for the failure of previous surgery may be attributable to an inadequately opened bone window [6, 7, 14]. In the case of bone formation, a suitable method for the endoscopic localization of the sac is important to avoid the recurrence of epiphora. The sac is localized on the anterior–superior region of the connection point of the middle concha, and variations are rarely encountered. An osteotomy should be performed exactly over the sac and the sac should be opened from the middle aspect, and not from the upper or lower aspects. The development of postoperative adhesions is a further reason for failure. Nasal pathologies, including septal deviations, concha bollosa, or concha hypertrophy, and hyperpneumatized ethmoid cells are factors that enhance adhesions. When these intranasal pathologies result in the failure of the previous operation, the subsequent adhesions can be readily determined during endoscopic revision surgery and be repaired during the same operation session. Another important point in revision cases is the usage of stents, which is relatively controversial. Although it has been reported in some studies that leaving the stents for an extended period may induce granulation formation, some authors still propose long-term use, particularly in revision case. In a literature review of revision cases, especially endoscopic revision, most authors used silicone stents for 3–6 months postoperatively.