Endoscopic DCR, Dacryocystorhinostomy
It is advantageous to access the lacrimal sac through the nasal cavity. By this intranasal approach incision over the face is avoided, the lacrimal pump mechanism is preserved. This procedure is very safe and can be performed under local anesthesia as a day care procedure.
A 4mm 0 degree wide angled endoscope is passed through the nasal cavity. The cotton pledgets are removed. The middle turbinate is identified. This structure is crucial for the identification of the sac. 2% xylocaine mixed with 1 in 1 lakh adrenaline is used for infiltration. The following areas are infiltrated with 1/2 cc of this solution:
- The root of the middle turbinate
- The substance of the middle turbinate
- The lateral nasal wall just lateral to the tip of the middle turbinate
The most important landmark for the location of the lacrimal sac is now looked for i.e. Maxillary line. This is nothing but a mucosal projection present in the lateral nasal wall.
After localising the position of the sac endoscopically, the lateral wall mucosa is incised with a sickle knife and is elevated using a Freer elevator. It will be of immence help if this incision could be placed well anterior to the location of the sac as this will allow adequate exposure of bone. The incision is made vertically from inferior to superior. After elevation the mucosa is removed using a Blakesley forceps.
The bone over the lacrimal sac area can be removed either by a punch forceps or by chiselling out the area. The sac should be exposed adequately. The position of the sac can be confirmed by asking the assistant to apply intermittent pressure to the orbit and looking for transmitted pulsations in the lateral wall of the nasal cavity.
Incising the sac: The sac is then incised using a sickle knife. It is better to completly remove the medial wall of the sac to ensure trouble free drainage.