Surgical outcomes of external dacryocystorhinostomy with flap versus without flap in acquired nasolacrimal duct obstruction

Epiphora is a common problem for which patients seek oculoplastic consultation, as it can hinder their day-to-day activities.[1,2] The most common cause for this symptom is nasolacrimal duct obstruction. The mainstay of treatment in nasolacrimal duct obstruction is dacryocystorhinostomy (DCR), which can be performed either externally or intranasally.[3,4] Various modifications in the DCR technique mushroomed over the past decade to bestow better surgical outcomes and to make this procedure less tedious and bloodless. Traditionally, external DCR with flaps is favored by the oculoplastic surgeon as chances of granulation tissue formation and fibrosis are less with mucosal apposition. However, fashioning of flaps and their anastomosis make this procedure cumbersome and sometimes result in torrential bleeding, which can negate the effectiveness of this procedure. To avoid insurmountable complications which are associated with flap DCR, external DCR without flaps has been advocated as it is a simpler procedure, requires less time to be completed, and causes less bleeding.[5,6] But there are very few studies which have commented on the productiveness of external DCR without flap. Hence, this study was undertaken at this center to compare the surgical outcomes of external DCR with or without flap in patients affected with nasolacrimal duct obstruction. A prospective, comparative, randomized interventional study was conducted from July 2021 to July 2023. A total of 116 patients diagnosed with nasolacrimal duct obstruction were included in the study. Fifty-eight patients in each group were randomly allocated after obtaining consent from all the participants. All patients underwent general ophthalmic examination, which included lacrimal irrigation test [Fig. 1a and b] and nasal assessment. In group A [Fig. 1c and d], external DCR with flap was done, whereas in group B, patients underwent external DCR without flap [Fig. 1e and f]. The Munk score was used to determine functional success, with an epiphora grade of 0 or 1 considered as successful and grade 3 or 4 considered as failure.[7]Figure 1: (a and b) Clinical image showing the procedure of modified lacrimal irrigation test through the upper punctum after punctal dilatation (black arrow) with a 27-G canula attached to a 1-ml insulin syringe (yellow arrow). (c and d) Intraoperative image of external dacryocystorhinostomy with flap surgery showing anastomosed anterior lacrimal sac flap (blue arrow) with nasal mucosal flap (yellow arrow). (e and f) Intraoperative image of the external dacryocystorhinostomy flapless surgery showing the common canaliculus facing the nasal cavity (yellow arrow) and the small lacrimal sac stump (yellow arrow) around the common canaliculus after excision of the lacrimal sac and nasal mucosal flapThe successful outcome measures were assessed by a subjective method (Munk score) as well as an objective method (patent lacrimal irrigation test). The clinicodemographic details of both groups are shown in Table 1. The anatomic success rate was 94.82% in group A as the lacrimal irrigation test was found patent in 55 patients out of 58 and 91.37% (53/58) in group B, and the difference was not statistically significant (P = 0.498, Chi-square test). The functional success rate was 89.65% in group A and 86.2% in group B, with no statistically significant difference (P = 0.49) between the two groups. Both resolution of epiphora and patent syringing at the end of 1 year were found in 86.2% (50/58) of cases in group A and in 81% (47/58) in group B (P = 0.46).Table 1: Clinicodemographic profile of the study populationOn literature review, we found that very few studies have compared the outcome of external DCR with flap and without flap and they had opined that DCR without flap anastomosis had the same surgical outcome as DCR with flap anastomosis [Table 2].[8-10]Table 2: Comparison of surgical outcome of our study with the outcomes of different studiesIt is concluded from our study that flapless external DCR is an effective treatment modality and is a viable alternative to conventional DCR as the current study found comparable successful outcomes between the two surgical techniques. External DCR without flaps is an easier technique to perform and learn, which can be performed by most general ophthalmologists and residents at any eye center without incurring any extra cost to the patients with less-steep learning curve. Failed DCR cases in which fashioning of mucosal flaps is a herculean task due to nonavailability of sufficient nasal and lacrimal sac tissue can be tackled effectively with flapless DCR technique.