Endonasal endoscopic dacryocystorhinostomy

Local anaesthesia is achieved as previously described (Chapter 15), but with particular attention paid to establishing vasoconstriction of the nasal mucosa (Figure 16.2); it is often necessary to directly infiltrate the submucosal space, anterior to the middle turbinate, using lidocaine 2% with 1:80,000 adrenaline. During the procedure localised haemorrhage may be treated with 1:1000 adrenaline solution applied to the bleeding points with neurosurgical patties.

Middle meatus

Middle meatus

Nasal floor

Septum

Figure 16.2 Right nasal space; topical anaesthesia and vasoconstrictive medications (both spray and packing) should be applied to these areas before surgery.

Septum

Nasal floor

Figure 16.2 Right nasal space; topical anaesthesia and vasoconstrictive medications (both spray and packing) should be applied to these areas before surgery.

Hartikainen CO2 or Nd: YAG

Endonasal dacryocystorhinostomy may be performed solely with surgical instrumentation, or with laser-assistance.

Endoscopic surgical dacryocystorhinostomy

After punctal dilation, a 21-gauge vitrectomy light pipe is inserted (unilluminated) into the lacrimal sac, along either canaliculus, and directed infero-medially at an angle of about 40° to the vertical. When illuminated, the light is usually visible on the lateral nasal wall, close to the middle turbinate (Figure 16.3a and 16.3b) and typically anterior to the uncinate process, behind the lacrimal ridge; it may be visible just inside the middle meatus, but sometimes the middle turbinate has to be pushed medially to create adequate operating space. The nasal mucosa overlying the light source is injected with further local anaesthetic.

A flap of nasal mucosa overlying the light source is raised using a Freer elevator (Figure 16.4a and 16.4b) and excised using Blakesley forceps (Figure 16.5a), or the mucosa curetted away with a J-curette, and the thin lacrimal bone pierced and elevated with the Freer elevator and removed with Blakesley forceps (Figure 16.5b).The heavy bone of the frontal process of the maxilla, lying anterior to the area of lacrimal bone removal, should be removed with a Kerrison rongeurs, fine chisel or drill - care being taken not to damage the mucosa of the underlying lacrimal sac or nasolacrimal duct. The light pipe may be used to tent the lacrimal mucosa and feel for residual overlying bone fragments.

The medial wall of the nasolacrimal duct and sac, tented over the light source, is readily opened with an angled keratome and any debris, such as mucopus or dacryoliths, may then be evacuated (Figure 16.6a and 16.6b). Transcanalicular silicone intubation is passed, care being taken not to damage the nasal mucosa whilst withdrawing the bodkins from the nose, and the ends of the intubation either knotted or clipped together within the nasal space (Figure 16.7a and 16.7b).

Endoscopic laser-assisted dacryocystorhinostomy

Two lasers are in common use for endoscopic laser-assisted dacryocystorhinostomy: the Holmium:YAG (2100nm pulsed) laser is used at 6-8 W for mucosa and 10 W for bone, although the shallow (0^4mm) tissue penetration of this laser is inadequate for removal of the frontal process of the maxilla. The potassium-titanyl-phosphate (KTP) laser, a 532nm superpulsed 15 W laser, is effective for the removal of thicker bone due to good tissue penetration (up to 4mm) and is very well absorbed by haemoglobin, generating excellent haemostasis during surgery.

After local anaesthesia has been induced, the transcanalicular illumination is set-up as for solely surgical endonasal dacryocyst-orhinostomy. Using a non-contact probe, the laser is used to ablate the nasal mucosa overlying the area of transillumination (Figure 16.8) and, if the laser is of adequate power, the underlying lacrimal bone; all laser-assisted endonasal surgery requires continuous intraoperative aspiration of the smoke plume. It may be necessary to manually remove chips of charred bone from the operative site, and it is often much quicker to remove thick bone (such as the frontal process of the maxilla) using rongeurs. When an adequate rhinostomy has been fashioned, the lacrimal sac and upper duct should be opened with a keratome and silicone intubation placed.

Was this article helpful?

0 0
How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

Get My Free Ebook


Post a comment