A simple and evolutional approach proven to recanalise the nasolacrimal duct obstruction

Abstract

Aim: To evaluate a new approach of recanalisation of nasolacrimal duct obstruction (RC-NLDO) in the treatment of the nasolacrimal duct obstruction (NLDO) and chronic dacryocystitis.

Methods: 583 patients with 641 eyes suffering from NLDO and chronic dacryocystitis were enrolled in this study. The RC-NLDO was performed in 506 eyes, with 135 eyes undergoing external dacryocystorhinostomy (EX-DCR) as controls. Patient follow-up for 54 months was evaluated by symptoms, dye disappearance test, lacrimal irrigation and digital subtraction dacryocystogram. The RC-NLDO was also performed in 12 rhesus monkeys for histopathological examination.

Results: The clinical success rates were 93.1% in 506 cases of RC-NLDO and 91.11% in 135 cases of EX-DCR. The success rates for second surgery were achieved in 85.19% on RC-NLDO and 40.0% on EX-DCR. No major intra- or postoperative complications were observed in the RC-NLDO group. The mean operative duration was 12.5 min for RC-NLDO and 40.3 min for EX-DCR (p<0.001). A pathological study in rhesus monkeys demonstrated that the RC-NLDO wounded epithelium in nasolacrimal duct healed completely within 1 month without granulation tissue formation.

Conclusion: The findings demonstrate that the RC-NLDO is a simple and effective approach proven to recanalise the obstructed nasolacrimal duct with a comparable success rate to EX-DCR.

Figure 1

Lacrimal canaliser (model WZC-III) with accessories. (I) Main instrument containing an on/off switch (A), an output power control (B) and a reset button (C) with three cable connectors (1, 2 and 3) for connections to accessories: a positive electrode cable that links to the high-frequency lacrimal probe (see part II), negative electrode tongs (D) and foot pedal (E), respectively. (II) Lacrimal probe images showing: (A) its 2.0 mm long, naked (without an insulating coat on the surface) and conducting tip 1.2 mm in diameter; (B) an 80 mm long and 1.2 mm diameter probe body with a thin layer of non-toxic and insulating coat on the surface; (C) a 60 mm long and 5 mm diameter head part of the probe covered by a rubber layer; (D) a special “buckle” structure of the probe top.

Figure 2

Digital subtraction dacryocystogram. (A) Completely obstructed right nasolacrimal duct and a normal left one before recanalisation of nasolacrimal duct obstruction (RC-NLDO) surgery. (B) Free flow of the contrast medium through the recanalised nasolacrimal duct to the inferior meatus 3 weeks after RC-NLDO operation.

Figure 3

Representative images showing histomorphological structures of the nasolacrimal duct mucosa in cross-sections of rhesus monkeys before and after recanalisation of nasolacrimal duct obstruction (RC-NLDO) surgery. (A, B) Normal morphological structure of nasolacrimal duct mucosa in rhesus monkey; (C, D) nasolacrimal duct mucosa in rhesus monkey immediately after RC-NLDO surgery, showing almost total loss of epithelium in nasolacrimal duct with a few residual cells on the basal membrane. (E, F) Notable migration of cells from adjacent residual epithelia, 1 week after surgery. The epithelial cells formed a single layer and loosely covered the surface of the basement membrane. Scattered or focal infiltrations of inflammatory cells were visible in the lamina propria. (G, H) Completely healed epithelium with two layers of cells similar to the normal controls, 1 month after surgery. There was no visible inflammatory cell infiltration in lamina propria. (I, J) Two months after surgery. (K, L) Three months after surgery. The epithelia in specimens from 2 to 3 months later became morphologically and histologically normal. Magnification: ×200 in images A, C, E, G, I and K; ×400 in B, D, F, H, J and L.