Evaluating failed dacryocystorhinostomy using computed tomography dacryocystography: a preliminary analysis of bony ostium characteristics in an Asian population.

Background: Although dacryocystorhinostomy (DCR) is the standard treatment for nasolacrimal duct obstruction, some surgeries are unsuccessful, and the reasons are not fully understood. By comparing successful and unsuccessful cases, this study investigated how computed tomography dacryocystography (CT-DCG) can help explain why these surgeries fail. Methods: This retrospective study included 34 failed and 16 successful DCR cases. The bony ostium was analyzed using CT-DCG with 3-dimensional (3D) reconstructions. The ostium position, dimensions (width, height, total area, and shortest side), shape regularity, and presence of obstructing residual bone were measured and assessed. Preoperative nasal endoscopy was performed, and intraoperative findings were documented to supplement the CT-DCG data. Results: Properly sized and positioned ostia were found in only 14.7% of unsuccessful cases, compared to 100% in successful cases (P<0.001). Failed cases showed higher rates of irregular ostium shapes (47.1% Conclusions: CT-DCG provides valuable insights into ostium characteristics in failed DCR cases, including irregular ostium shape and residual obstructing bone. Although findings from nasal endoscopy and surgical observations were found to be supportive, more detailed and quantifiable information was provided by CT-DCG. These findings highlight the importance of comprehensive preoperative assessment and meticulous surgical technique in DCR procedures.