Fig. 2

Illustration of the steps of the operation. (a) Remove the frontal process of the maxilla and move the sutura lacrimal maxillaris forward with the rongeur (black arrow). (b) Use an electric drill to grind the thicker parts of the maxilla frontal process upper bone, if needed (black arrow). (c) After producing the bone window, expose the inner wall of the lacrimal sac (black arrow). (d) From the lacrimal point, insert the lacrimal probe into the lacrimal sac (black arrow) after endoscopy has verified accurate exposure of the lacrimal sac (black arrow). (e) A longitudinal incision is made along the lacrimal sac wall, and a crosscut incision is then made at the top and bottom of the initial incision to form a base at the edge of the lacrimal sac wall and form the mucosal flap. Flip the mucosal flap backward to expose the front mucous membrane of the uncinate process, leaving the lacrimal sac cavity completely open (white outline). (f) Blood should be absorbed by stuffing gauze into the lacrimal sac (white arrow), and the lacrimal sac mucosal flap should be pinned to reduce movement and bleeding