Materials and methods

In this retrospective, non-randomised study, 105 patients underwent modified primary endoscopic DCR at our centre, from May 2012 to March 2013, using powered instrumentation but with no stenting. The institutional ethical committee approved the study protocol.

Data collected included patient age, gender, laterality, pre-operative examination results, intra-operative findings and follow-up results.

All patients underwent pre-operative rigid nasal endoscopy, and were assessed using nasolacrimal system syringing and dacryocystography. The patients’ characteristics are described in Table I.

Table I

Patient characteristics

The modified powered endoscopic DCR technique used is described here. After consent and pre-operative evaluation of the patient, surgery was performed under general anaesthesia. After the induction of anaesthesia, the patient was placed in a supine position, with 20–30-degree head-end elevation and their head slightly rotated towards the right side.

A 0-degree 4 mm endoscope was used for the procedure. Any cases of anterior septum deviation or other anatomical variations were addressed at the initial step in the procedure.

Nasal packing was achieved using 1:1000 adrenaline-soaked pledgets to decongest the nose (Figure 1). Local anaesthetic infiltration was avoided, as oozing can fog the endoscope, obscuring vision. The packing was placed medial to the axilla of the middle turbinate and anterior to the uncinate process.

Fig. 1

Endoscopic image of left nasal cavity after decongestion with 1:1000 adrenaline. PU = uncinate process; MT = middle turbinate.

An inferiorly based flap was raised in the lateral nasal wall to expose the lacrimal bone and the frontal process of the maxilla using a knife. A superior incision was placed just above the axilla of the middle turbinate. An anterior incision was placed 8 mm anterior to the axilla of the middle turbinate, which was in front of the uncinate, posteriorly (Figure 2).

Fig. 2

Endoscopic image showing superior and anterior incisions (arrows) for inferiorly based flap.

A 0.5 × 0.5 cm section of the mucosa in the flap in front of axilla was incised and removed using a Rosen elevator or a blade (Figure 3). This was the mucosa overlying the lacrimal sac. The Rosen elevator was used to gently elevate the flap from the bone in an anterior to posterior direction. From the posterior edge, the flap was gently pulled in the inferior direction to free it from nasal mucosa using Blakesley forceps. The use of suction was avoided.

Fig. 3

Mucosa in the flap overlying the lacrimal sac was incised (0.5 × 0.5 cm incision inside the flap (arrows)) and removed.

Pledgets were used to secure haemostasis during flap elevation (Figure 4). The inferiorly based flap was rotated on itself and placed on the inferior turbinate. Any adhesions to the bone or nasal mucosa were cut using scissors.

Fig. 4

Endoscopic image of left nasal cavity showing elevation of the flap.

The frontal process of the maxilla was nibbled in a posterior to anterior direction, just above the flap, to the anterior edge, using a 2 mm Kerrison rongeur. The tip of the Kerrison rongeur was then engaged at the posterior-most edge of the frontal process of the maxilla and bone was nibbled in the same direction. Traction was maintained medially to prevent pressure injury to the lacrimal sac during this process.

Drilling was conducted using a DCR burr to remove the superior thick bone and expose the fundus of the sac, without applying pressure, thereby avoiding lacrimal sac injury (Figure 5). The thin lacrimal bone was gently elevated from the lacrimal sac. Complete bone removal was ensured.

Fig. 5

Endoscopic image showing bone removal with rongeur and drill using dacryocystorhinostomy burr.

After removal of bone, the endosteal layer was observed on the medial wall of the sac (Figure 6).

Fig. 6

Endosteal layer being removed.

In the modified technique, removal of the endosteal layer was performed separately from that of the endothelial layer of the sac. The endosteal layer was removed with a sickle knife, gently and in a downward direction (Figure 7).

Fig. 7

Endoscopic image showing endothelial layer of lacrimal sac completely exposed.

The medial wall was then incised using a number 11 blade, allowing the accumulated pus to drain. Anterior and posterior flaps of the medial wall of the sac were created, thus marsupialising the lacrimal sac. Canalicular openings were visualised. Syringing was performed to remove mucus plugs and ensure patency.

The inferiorly based flap was repositioned and approximated with the nasal mucosa so that no bone was left exposed. The anteriorly based flap was repositioned on the inferiorly based flap and the posterior flap was placed on the uncinate. Tissue glue was used to keep the flap in position. Nasal packing was avoided and antibiotic ointment was instilled using a syringe.

Post-operatively, the nose was irrigated using a sodium chloride solution. Antibiotic eye drops were instilled following irrigation. Intra-nasal debris was removed during the first post-operative visit. Syringing was conducted weekly for four weeks. Patients were followed up weekly for 1 month, then at 3 months, 6 months and 12 months (Figure 8).

Fig. 8

Post-operative endoscopic visualisation of ostium.