Cadaveric Evaluation of the Canalicular-Lacrimal Sac-Mucosal Folds and Clinical Implications.

Purpose: The purpose is to study the anatomical variations of the characteristic mucosal folds at the canalicular-lacrimal sac junction and their potential clinical implications.

Methods: Twelve lacrimal drainage systems of six fresh frozen Caucasian cadavers were studied to assess the openings of the common canaliculus into the lacrimal sac. A standard endoscopic dacryocystorhinostomy was performed until complete lacrimal sac marsupialization and reflection of the flaps. All specimens were subjected to clinical assessment of lacrimal patency via irrigation. A high-definition nasal endoscopy assessed the internal common opening and the mucosal folds in its close vicinity. Probing at the internal common opening was performed to aid in the assessment of the folds. Videography and photo documentation was performed.

Results: All 12 specimens had a single common canalicular opening. Ten of the 12 specimens (83.3%) were noted to have canalicular/lacrimal sac-mucosal folds (CLS-MF). Anatomical variations were noted across these 10 specimens and included inferior 180° (n = 6), anterior 270° (n = 2), posterior 180° (n = 1), and 360° CLS-MF (n = 1). Cases were randomly chosen to demonstrate the clinical implications of misinterpreting them as canalicular obstructions or the potential to cause an inadvertent false passage.

Conclusion: The inferior 180° was the most common CLS-MF noted in the cadaveric study. It is helpful for clinicians to recognize the prominent CLS-MF and their clinical implications intraoperatively. Further fundamental work is needed to characterize the anatomy and the possible physiological role of CLS-MFs.