Intranasal location of lacrimal sac in Thai cadavers

Background: Many current literatures have described that the lacrimal sac is located just anterior to the anterior attachment (axilla) of the middle turbinate. However, there was no data on the exact boundary of the sac, especially the distance related with a permanent landmark such as the middle turbinate attachment. Objective: Determine the intranasal location of the lacrimal sac related to the middle turbinate attachment in Thai fresh cadavers. Methods: The study was performed in 26 Thai fresh cadavers, donated to Khon Kaen University, Thailand between July 2006 and July 2007. The height and width of the lacrimal sac were recorded, as well as the distances from the upper, lower, anterior and posterior border of the lacrimal sac to the axilla of the middle turbinate were measured. Results: The mean height and width of 52 lacrimal sacs were 11.2 and 6.2 mm. The mean distances from the upper, lower, anterior, and posterior border of lacrimal sac to the axilla of the middle turbinate were 4.9 mm (95%CI=4.4-5.4), 5.6 mm (95%CI=5.1-6.1), 3 mm (95%CI=2.4-3.6), and 2.9 mm (95%CI=2.3-3.5), respectively. The upper border of all lacrimal sacs were located superior to the axilla of the middle turbinate (95%CI=93.1-100), and posterior border of 44 sacs (85%, 95%CI=72.5-92.0) were located posterior to the axilla. Additionally, the anterior wall did not extend anterior to the anterior attachment of the middle turbinate in 21% of the sac. Conclusion: This study revealed the more exact intranasal location of lacrimal sacs. This is useful for surgeons to perform adequate endoscopic dacryocystorhinostomy to prevent postoperative lacrimal sump syndrome.