How will you perform endonasal DCR surgery with conventional instruments?
Carefully pre-operative assessment done. If needed the correction of septal deviation and osteomeatal complex disease is done.
Syringing and probing has to be done to R/o proximal obstruction where DCR is not helpful.
Lacrimal sac lies just lateral to the maxillary line (a body ride extending inferiorly from the anterior attachment of middle turbinate to the highest point of the inferior turbinate )
The lacrimal sac extends posteriorly up to the anterior border of the uncinate process.
It is located 5 cm posterior to anterior nasal spine.
Antiseptic dressing (with Betadine and spirit) and draping done.
Patient put in supine position c head slightly elevated and turn towards the surgeon.
General anesthesia given via oral endotracheal tube with pharyngeal pause.
Ask the patient to breath through mouth if operation is done under local anaesthesia to avoid fogging of the scope.
Apply cothons soaked in 10ml of 4% lignocaine mixed with 1 ml. 1 in 1000 adrenaline over the following areas:
Nasal cavity floor
Posterior end of the middle turbinate and
Anterior aspect of nasal roof
1.5 ml of 2% lignocaine 1:100000 adrenaline injected submucousally :
anterior to the middle turbinate (atrium of nose)
Anterior end of the middle turbinate
0.5 also injected externally just below the medial canthus to provide vasoconstriction around the lacrimal sac.
Incision is made in the mucosa overlying the anterior lacrimal crest. The incision is in the shape of a 1cm circle and with Freer’s elevater Mucosal Flap is removed with blakesley forceps.
Bone drilled with diamond burs to expose the complete anterior posterior extent of the medial wall of lacrimal sac.
Identification can be easier by passing the endoilluminator (0.9mm fibreoptic bundle) via the dilated inferior canaliculus into the nose.
Superior limit of bone drilling →Fundus of the lacrimal sac
Inferior limit → Up to level of insertion of anterior end of inferior turbinate.
Head of the middle turbinate may need trimming for adequate exposure.
Infundibulotomy may be required for pneumatized uncinate process or anterior ethmoidal disease.
Lacrimal canaliculi is dilated and a lacrimal probe is passed to it. Indentation on the medial wall of lacrimal sac, produce by the probe is visualized in the nasal cavity with the scope.This indentation is cauterized in a circular fashion with insulated ball probe.
Cruciate incision made over the cauterized area with sickle knife. Edges of incision is excised c through cutting 45º upturned forceps to create a 1 cm circular opening in the medial wall of lacrimal sac excised to produce a direct communication b/w lacrimal sac and nasal cavity .
Alternatively: Micro inscision are used both inferiorly and superiorly to create anterior and posterior flaps. There flaps of the sac mucosa are then placed in continuity with the mucosa of the nasal wall.
An adequate excision is considered if the common canaliculus opening can be clearly visualized by 30º endoscope.
Syringing done to check for patency or an external pressure applied on the lacrimal sac or if ↓LA, patient asked to blink his eyes to visualize the escape of lacrimal fluid. Syringing continued till clear saline flows from the sac.
Stenting c 0.4 mm silicone tube stent from the canalicular into the nasal cavity id optional.
Nasal cavity packed with Ab- steroid ointment soaked gauze/merocel for 12-24 hrs syringing done 48 hrs after operation to check for patency again.
Normal saline douching two times daily for 3 weeks.