Surgical and Anatomic Considerations in Endoscopic Revision of Failed External Dacryocystorhinostomy

Abstract

Objectives: Identify key clinical and anatomic considerations in endoscopic revision DCR (r-EnDCR) following failed external dacryocystorhinostomy (ExDCR). Study Design: Case series. Methods: A retrospective review was performed of patients undergoing r-EnDCR after failed ExDCR over the past 6 years. Those with primary or previous EnDCR, proximal nasolacrimal procedures, and nasolacrimal lesions were excluded. All patients had pre-operative maxillofacial computed tomography (CT). Data were collected on patient demographics, clinical characteristics, and radiographic findings. We developed a classification system for the anterior ethmoid-lacrimal fossa complex. Results: Twenty-five r-EnDCRs were performed on 22 patients (18 female, 4 male; average age 50.0 yrs) after failed ExDCR. Concurrent sinusitis and previous maxillofacial trauma was seen in 8% (2/25) and 12% (3/25), respectively. CT analysis demonstrated agger nasi pneumatization in 88% (22/25), of which 77% (17/22) partially overlapped the medial aspect of the lacrimal fossa, resulting in a DCR ostium located within the middle meatus. The presence of ipsilateral septal deviation, concha bullosa, and middle turbinate lateralization or scarring to the lateral nasal wall was seen in 24% (6/25). Conclusions: ExDCR is a highly successful operation for nasolacrimal duct obstruction. When failures do occur, variability of the anterior ethmoid anatomy often plays an important role. CT imaging and endoscopy, which are not routinely performed prior to ExDCR, can help define the pattern of agger nasi pneumatization as it relates to the failed surgical DCR ostium. An understanding of the relationship between the agger nasi cells and the lacrimal fossa is essential for successful r-EnDCR.