Dr. Ajay Manickam MS ENT PGTR.G. Kar Medical college & Hospital

• Light Amplification by Stimulated Emission of Radiation

• Quantum Theory – interaction of light & matter

• 4 lasers FDA approved• Visible spectrum1. Argon laser (514nm)2. Potassium titanyl phosphate KTP (532nm)• Infra red spectrum1. Carbon dioxide CO2 (10600nm)2. Erbium yttrium aluminium garnet YAG

(2960nm)

• Laser stapedotomy and laser revision stapedectomy• 4 Requirements 1.Precise optics2.Efficient absorption by bone & collagen3.Minimal heating of perilymph4.No damage to inner ear or facial nerve structures from

photons transmitted through perilymph

• Mechanical stapedotomy do not produce a round symmetrical stapedotomy

• 81% failure of stapes surgery – prosthesis migrated out of oval window fenestration onto solid fixed stapes footplate.

• Few hits of pulsed co2 laser beam focussed to a 0.6 mm spot size

• 0.6 mm Fisch trocar used to freshen the margins – PRECISION – eliminates collagen seal

• Improved stapedotomy prosthesis – should measure 0.25 mm longer- resists displacement out of stapedotomy during valsalva

• Post op contracture can lift prosthesis – commonest complication

• 3 indications for seal1. Perilymph gusher2. Footplate fracture or mobilization3. Stapedotomy too large for prosthesis

• Has a profound advantage• Ant tympanotomy • Determine margins & depth of the

oval window• Any residual stapes footplate• Relationship of prosthesis to the

vestibule

• Vaporize the collagen neomembrane – until margin of oval window precisely identified

• Tissue surrounding prosthesis is vaporized

1.Identify residual stapes footplate2.To determine exact length required for

new footplate3.Stabilize new prosthesis in the centre of

oval window

• Incus eroded lippy moon Robinson offset prosthesis• Incus too short – Leinski malleus to oval window

prosthesis – titanium aerial prosthesis -sterile allograft collagen membrane placed between TM and prosthesis

• Haemostasis – inaccessible to bipolar cautery• Meticulously vaporize unwanted soft tissue – less

damage to inner ear- exposure to infection is reduced• Oval window obliterated by cholesteatoma, granulation

tissue, hyperplastic mucosa and adhesions.

• Acoustic neuroma, glomus tumours, skull base tumour• Epidermoid carcinoma off adventia of carotid artery• Benign tumours off a dehiscent facial nerve

• EM energy of lasers • Emission spectroscopy – cancer cell specific great

degree of accuracy• Inner ear endoscopy and spectroscopy – cannulate the

ear with tiny optical fibres and perform emission spectroscopy at various sites in vestibular and cochlear partitions.