Anatomical requirements for dacryocystorhinostomy ostium patency.

Purpose: To identify anatomical factors affecting the outcome of dcryocystorhinostomy (DCR).

Methods: The study included the results of dacryocystography in 73 patients after DCR: 37 cases of failed DCR and 36 cases of successful DCR. Biometric characteristics of the formed ostium were evaluated: the horizontal size of the bony "window" and the soft tissue part of the ostium, the vertical size of the bony "window" and soft tissue ostium, the height of the fragment of the remaining bone above and below the line of the common canaliculus, and the height of the "pocket" formed below the lower edge of the ostium. Statistical analysis was performed using parametric and non-parametric statistical methods. Differences were considered significant at p ≤ 0.05.

Results: Intergroup differences were identified in the values of the maximum horizontal size of the bony "window" (p = 0.015), the maximum horizontal size of the soft tissue "window" (p < 0.001), the maximum vertical size of the soft tissue "window" (p < 0.001), and the height of the fragment of the remaining bone below the level of the common canaliculus to the edge of the formed ostium (p = 0.004).

Conclusion: The stage of forming the bony "window" influences the success of DCR. Not only the position of the "window" is important, but also the geometric properties of the formed ostium.