ENDOSCOPE ASSISTED

MIDDLE EAR SURGERY

BY

RAMA RAJU

•“ endoscopy is an adjunct to microscope but never a substitute”

Endoscopes offer the surgeon the :

• capability of wide field visualization with minimal exposure,

• looking behind the obstructions or overhangs and

• peering into recesses with much less requirement for surgical exposure than demanded by conventional techniques.

• endoscopes help in angled vision at tip allowing off line-of-site visualization

Off Line-of-Sight Structures:

• Middle ear Epitympanic recess

• Facial recess

• Sinus tympani

• Eustachian tube

• Hypotympanum

MIDDLE EAR ENDOSCOPY – POTENTIAL INDICATIONS:

• Unexplained conductive hearing loss

• Trauma

• Cholesteatoma

• Perilymph fistula

• Follow-up (second look) cholesteatoma

FACIAL RECESS:

• Shallow depression on the posterior wall of tympanic cavity

Relations:

Medial wall : PE, vertical segment of FN

Lateral wall : bony annulus

SINUS TYMPANI:

• Relations:

Sup- ponticulus

Inf- subiculum

Lat – mastoid segment of facial nerve

SUPRA TUBAL RECESS:

ST CLASSIFICATION WITH ENDOSCOPY:• Classical shape:

medial to the facial nerve and to the pyramidal process

• Confluent shape: absent ponticulus

• Partitioned shape: when a ridge of bone extending from the third portion of the facial nerve to the promontory area is present, separating the sinus tympani into two portions (superior and inferior)

• Restricted shape: when a high jugular bulb is present thus reducing the size of ST

TRANSTYMPANIC ENDOSCOPY• Endoscopy through

perforation /myringotomy for a limited middle ear exploration.

TECHNIQUE:

• Position- supine

• Local anaesthetic- phenol solution

• Myringotomy incision : at site of pathology (PLF-half way b/w RWN shadow and distal end of long process of incus

ENDOSCOPY IN CHRONIC EAR SURGERY

• As a adjuvant for removal of cholesteatoma

• For cholesteatoma in deep recesses

• For ds limited to aditus ,antrum ,ST,FR (mastoidectomy avoided)

• Perform intact canal wall mastoidectomy +endoscopy(avoids canal wall down technique)

• Used if firm adhesions of cholesteatoma sac to recesses , blind elevation results in tearing the matrix and residual ds,

• Lessen the need for second look procedure

• Thomassin et .al:

Only canal wall up procedure: 47.7% has residual procedure and planned for second stage procedure

Canal wall up+endoscopic removal: only 5.5% required second stage procedure , results are on par with canal wall down procedure

DISADVANTAGES:

• One handed surgery

• Bleeding hard to manage

• Passing instruments past endoscope

• Fogging

• Cannot be very helpful if disease involves mastoid antrum

ENDOSCOPIC TYMPANOPLASTY

MOSTLY DONE IN

• Anterior perforation / anterior bony overhang

• Marginal perforation

ENDOSCOPIC ASSISTANCE IN STAPEDOTOMY:

• Anterior crus and anterior part of foot plate better visualised using endoscope than microscope

PERILYMPH FISTULA EXPLORATION:

• ME endoscopy proably improve the ability to identify true peri-lymph fistula and reduce the number of false positive examination whereas open surgical exploration cannot eliminate the artefactual pooling of infilitrated anaesthetics and surgery induced transudates

ENDOSCOPY OF EAC AND T.M

• Photo documentation

• T.M and medial E.A.C (canal stenosis/obstruction)

• Bony canal defects

• Recesses

• To determine depth and presence of cholesteatoma in retraction pockets