Endonasal Anatomy Of Lacrimal Sac To Andoscopic Transnasal Dacryocystorhinostomy

Objective: This study provided clinical guidance for the endoscopic transnasal dacryocystorhinostomy. Method: 15 adult cadavers (30 sides) were studied on projection anatomy of lacrimal sac on the lateral wall of nasal cavity and the relationship between lacrimal sac and inner canthal ligament. Result: A major portion of the sac (2/3) is located above the insertion of the anterior of the middle turbinate (the axilla of the middle turbinate) and, quite a part (1/3) of the sac lies above the entry point of the common lacrimal canaliculus. Inner canthal ligament almostly projects on the middle of the sac. The insertion of the anterior of the middle turbinate could pass the facies posterior(11 sides) even the long axis(1 sides) of lacrimal sac. A localization method based on inner canthal ligament shows the degree of accuracy of 80%. Conclusion: Dacryocyst iodized oil opacification CT scan should be performed, surgical stoma . location is about 1.5-2.0mm above and slightly anterior to the insertion of the anterior of the middle turbinate. A localization method based on inner canthal ligament shows a high degree of accuracy . The common lacrimal 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 exactly as a identification marker.