[Endonasal anatomy of lacrimal sac to endoscopic transnasal dacryocystorhinostomy].

OBJECTIVE

To provide clinical guidance for the endoscopic transnasal dacryocystorhinostomy.

METHOD: Fifteen adult cadavers (30 sides) were studied on the projection anatomy of lacrimal sac on the lateral wall of nasal cavity and the relationship between lacrimal sac and inner canthal ligament were studied, too.

RESULT: A major portion of the sac (2/3) was located above the insertion anterior to the middle turbinate and, quite a part (1/3) of the sac lied above the entry point of the common canaliculus. Inner canthus ligament almost projected on the middle of the sac. The insertion of the front of the middle turbinate could pass the posterior facies (11 sides) even the long axis (1 side) of lacrimal sac. A localization method based on inner canthus ligament showed the degree of accuracy of 80%.

CONCLUSION

Dacryocyst iodized oil opacification CT scan should be performed. Surgical stoma location is about 1. 5-2. 0 mm above and slightly anterior to the insertion of the middle turbinate. A localization method based on inner canthus ligament shows a high accuracy. The common canaliculus entry point is comparatively permanent, a laser optical fiber should be used for lacrimal passages exploration on the surgery, and the light spot directed toward lacrimal bone on the nasal lateral wall is exactly as an identification marker.