Myringoplasty and Various Graft Materials

Dr Vaibhav Lahane

Definition :-

Myringoplasty is a procedure used to repair a perforated tympanic membrane using a graft material , without need to examine the middle ear.

The idea of tissue grafting is to replace the missing fibrous element of the TM and to allow normal epidermis and mucosa to regenerate over the graft.

Advantages :-

1. Restoring the hearing loss2. Checking repeated infections from EAC and ET3. Checking aeroallergens reaching the exposed middle ear mucosa l / t persistent ear

discharge.

Myringoplasty should not be confused with type I tympanoplasty.Though both refer to TM perforation repair , T plasty entails exposure of the middle ear to inspect and also ensure ossicular integrity.

Indications :-

1. Central perforation which has been dry atleast for a period of 6 weeks.2. As a follow up to mastoidectomy procedure to recreate the hearing mechanism.

Contraindications :-

1. Active discharge from middle ear2. Nasal allergy 3. Otitis externa4. Ingrowth of squamous epithelium in middle ear5. When other ear is dead or not suitable for hearing aid rehabilitation6. Children below 3 years.

Prerequisite :-

1. Central perforation which has been dry for atleast 6 weeks2. Normal middle ear mucosa3. Intact ossicular chain4. Good cochlear reserve5. Patent eustachian tube6. There should be no focus of infection in PNS , nose or nasopharynx

Pre operative evaluation :-

1. Detail history of patient 2. Physical examination3. Otoscopic examination - Ear canal

TM - Perforation – location, size - Retraction pockets, granulation tissue - Status of middle ear through perforation

4. Tuning fork test 5. Audiometry6. Tympanometry – eustachian tube patency 7. Facial nerve

Preparation :-

• Proper I/V/W consent .• XST and inj T.T 005 cc i.m• A small portion of the hair is shaved just above the pinna, if a temporalis graft is to be used.

Anesthetic Considerations :-

• In children, the procedure is performed under general anesthesia.In addition, infiltration of a local anesthetic (1% lidocaine with 1:100,000epinephrine) into the ear canal and the graft site is preferred.• In adults , sedation with fortwin and phenargan is given along with local anaesthetic

infiltration.

Position of patient :-

Supine position with head turned towards the opposite side with head touching the edge of table.The ear to be operated is up.

Instruments required in myringoplasty :-

Surgical approaches for myringoplasty :-

1. Endomeatal or transcanal approach 2. Endaural approach 3. Post aural approach

By going through these approaches , we raise the tympanomeatal flap to enter into middle ear.

1. Endomeatal approach (Rosen’s incision) :-

Requires wide meatus and EAC.It consists of two parts –a. A small vertical incision at 12 o’clock

position near annulusb. A curvilinear incision starting at 6 o’clock

position to meet 1st incision in the posterosuperior regions of the canal , 5-7 mm away from the annulus.

2. Endaural approach :-

Made through Lempert’s incision. It consists of two parts :-Lempert I – It is semicircular incision , made from 12 ;o’clock to 6 o’clock position in the posterior meatal wall at the bony cartilaginous junction.

Lempert II – Starts from 1st incision at 12 o’clock & then passes upwards in a curvilinear fashion between tragus & crus of helix.

3. Post aural or Wilde ‘s incision :-

Starts at the highest attachment of the pinna , follows the curve of retro auricular groove , lying 1 cm behind it , ends at mastoid tip.

Procedure :-

Under all aseptic precautions , P and D done.• Local anesthetic agent (2 % xylocaine

mixed with 1 in 10,000 adrenaline injection.) is injected in four quadrants of cartilagenous canal & bony external canal is injected in subperiosteal plane at 6 and 12 o’clock.

• The anesthetic agent is also injected above the pinna, the tragus, or the lobule, when a graft is to be harvested from one of these sites.

• When a fascia graft is desired, an incision is made superior to the pinna just above the hairline , and the graft is excised.

• Still another highly successful alternative is to remove a small piece of fat from the ear lobule. The incision is made on the posterior surface of the lobule to hide the scar, but caution should be exercised while dissecting the fat with scissors so as to prevent a “button hole” perforation of the Lobule.

• As an alternative to a fascia graft, a perichondrial graft can also be used. An incision for the perichondrial graft is made in the tragus, slightly toward the meatus, which leaves the tiny scar hidden and perichondrial graft is excised

Techniques of myringoplasty :-

1. Underlay :-

This is a simpler and commonly used technique. Ideal to repair small and easily visualized perforations Here the graft is placed under the tympano meatal flap which has been elevated. Major advantage - it is easy to perform with a good success rate.

2. Overlay :-

Difficult technique to master. Typically reserved for total perforations, anterior perforations, or failed underlay

surgery. Here the graft material is inserted under the squamous layer of the ear drum. It is a difficult task , peeling only the skin layer away from the tympanic membrane,

placing the graft over the perforation and redraping the skin layer.

Underlay technique :-

1. Freshening the margins of perforation using a sickle knife of an angled pick.

2. A vascular strip is created in the external auditory canal by making incision at tympanomastoid and tympano squamous suture line corresponding roughly to 6 o clock and 12 o clock positions. The incision extend upto the annulus.

3. Elevation of tympano meatal flap up to the level of the annulus.

4. Elevation of the annulus and incising the middle ear mucosa.

5. Freeing the tympano meatal flap from the handle of malleus by sharp dissection of the middle ear mucosa.

6. Placement of graft - middle ear is packed with gel foam soaked with antibiotic. A proper sized graft is placed so that its edges extend under the margins of perforation all around and small part also extends over the posterior canal wall.

7. TM flap is reposited. Bits of gelfoam is placed around the edges of the raised flap. One gel foam bit is placed over the sealed perforation.

8. Closure and dressing done.

Video – myringoplasty

Underlay myringoplasty

Post operative care :-

1. Patient is discharged on post of day 1.2. Mastoid dressing is changed on next day morning.3. Showering is allowed provided the patient places a cotton ball soaked with

petroleum ointment in outer ear canal.4. Water should be kept away from postauricular incision for 2 days.5. Nose blowing should be avoided. If snizzing is unavoidable , then mouth should be

kept open.6. Medications in the form of antibiotics , antihistaminics and analgesics are

prescribed.7. 1st post op visit – after 1 week – suture removal is done8. 2nd visit –after 3 to 4 weeks – gel foam over graft is gently suctioned away.9. Audiogram is obtained 4 to 6 months after surgery.

Complications of underlay myringoplasty :-

1. Middle ear becomes narrow.2. Graft may get adherent to promontary.3. Anteriorly graft may loose contact from remnant of tympanic membrane l / t

antrior perforation.

Advantages and disadvantages of underlay technique –

Advantages :-

1. Simple and easy to perform when perforation is small.

2. Avoids extensive dissection of anterior meatal skin, thus preventing blunting of anterior recess.

3. Ensures healing of drum at correct level relative to fibrous annulus and osseous remnant.

Disadvantages :-

1. Reduction of middle ear space.

2. Limited bed of raw area for graft reception.

3. Difficult graft placement if perforation extends more anteriorly.

4. Three layer formation of TM is unlikely.

5. Anterior reperforation.

6. Anterior tympanomeatal cholesteatoma.

7. Blunting of anterior tympanomeatal angle.

Overlay technique :-

Graft is harvested.

Incision is made over meatal skin (shown in figure ) & meatal skin raised along with all epithelium from the outer surface of tympanic membrane remnant preserved to be used later.

Graft placed on the outer surface of tympanic membrane. A slit is made in the graft to tuck it under handle of malleus.

Meatal skin removed earlier is now replaced , covering the periphery of the graft. Graft is supported with gelfoams in EAC.

In the overlay technique, the graft is placed lateral to the annulus and any remaining fibrous middle layer after the squamous layer has to be carefully removed.

In this technique, there is an excellent visualization of the anterior meatal recess, which is important in cases of anterior perforations reaching the anterior annulus.

A modification of overlay technique is to place the anterior edge of fascia graft under the annulus after removing the epithelium from its undersurface. This prevents blunting of anterior canal is seen as a complication of overlay technique.

Complications of overlay technique :-

1. Blunting of anterior sulcus.

2. Epithelial pearls – they are epidermal cyst , when squamous epithelium is buried under the graft.

3. Lateralization of graft – graft loses contact from the malleus handle resulting in conductive loss. It is prevented by tucking the graft under the handle.

Advantages and disadvantages of overlay technique :-

Advantages :-

1. Anterior recess can be visaulized

2. Anterior overhang can be drilled out

3. Middle ear space is not reduced

4. Take up rate should be high as graft bed is broad

Disadvantages :-

1. Poor exposure of vital areas of tympanic cavity

2. Delayed healing 3. Epithelial pearls from remanants of drum

epithelium4. Lateral displacement of graft5. Inclusion or residual cholesteatoma6. Retraction pocket due to ET dysfunction7. Blunting of anterior meatal recess due to;• Accumulation and organization of

blood deep to graft• Inadequate removal of anterior canal

hang

Causes of failure of myringoplasty :-

1. Upper air way infection2. Type of surgical procedure3. Type of tissue used to graft the perforation4. Trapped epithelial seed cells post operatively

Type of surgical procedure –

1. Exposure of ear drum – in some cases Prominent bulge in the anterior canal wall obscuring the anterior rim of the ear drum and the anterior portion of the annulusis present. Myringoplasty performed under these conditions may fail because the graft could medialize in the anterior recess area. This scenario can be prevented by elevation of Wright Guilford flap in these patient. This flap is raised from over the bulge of the anterior canal wall through an incision made circumferentially lateral to the ear drum

2. Preparation of drum head before grafting:

This involves freshening the edges of the perforation. The under surface of the tympanic membrane must be scraped using a instrument called drum scraper. The aim is to create raw area on the undersurface of the ear drum facilitating a better graft take.

3. Positioning of graft –

In underlay technique of myringoplasty , the graft must be positioned in such a way that it lies under the handle of malleus. The handle of malleus is exteriorised. This method prevents lateralisation of the graft due to pull by the migating squamous epithelium.Gelfoam packs must be placed in the middle ear cavity inorder to enhance the nutritional status of the graft material, it also helps to prevent medialisation of the graft

Presence of secondary pathology in the middle ear:

The following disorders of the middle ear can lead to graft rejection:

1. Tubal obstruction2. Presence of cholesteatoma3. Presence of tympanosclerosis4. Presence of adhesions binding the handle of malleus to the promontory5. Ossicular chain necrosis

Various Graft materials used :-

Are classified as –

1. AUTOGRAFT : same person 2. ISOGRAFT: genetically identical twins3. HOMOGRAFT: Another person( SAME SPECIES) 4. HETEROGRAFT: Another species like: fetal serosa, bovine jugular vein

ADVANTAGES OF AUTOGRAFT

5. No immunological reaction6. Inexpensive7. No risk of HIV or other infections

TYPES OF AUTOGRAFT:

1. Temporalis fascia2. Tragal cartilage3. Conchal perichondrium4. Tragal/conchal cartilage5. Periosteum6. Vein7. Fatty tissue from ear lobule8. Fascia lata9. External auditory canal skin10. Dura11. Heterotropic skin : full thickness and split thickness

• Temporalis fascia, tragal & conchal perichondrium and fascia lata free grafts provide viable autograft material for myringoplasty.

• These materials are mesodermal in origin which excludes the risk of iatrogenic cholesteatoma.

Temporalis fascia :-

Temporalis muscle fascia was first used in myringoplasty by Ortegren (1958-59), Heermann (1961) and Storrs (1961).Temporalis fascia remains the most commonly used material for tympanic membrane reconstruction, with a success rate of 93% to 97% in primary surgery.

ADVANTAGES OF TEMPORALIS FASCIA :

1. Location of donor site2. Easy to harvest3. Close biological and segmental kinship4. LOW BMR – requires less nutrition ----- high survival5. No size limitation6. The only suitable autologus memberane for reconstruction of tympanic cavity and

ear canal7. It can be used as onlay /intermediate/underlay grafting8. It can be used as more than one piece , overlapping the other .9. It can be used in sandwich techniques as one of the grafts with canal skin on the

fascia.

Disadvantages of temporalis fascia :-

1. Can eventually become thin and atrophic. 2. It lacks elasticity and resistance to pressure changes in the external ear canal.

Video

Cartilage and perichondrial graft :-

Advantages over temporalis fascia –

1. More rigid and resistant to pressure changes in EAC2. Good long-term survival.3. Nourished largely by diffusion.4. Relatively resistant to infection.5. Feasibility of assiculat reconstruction at the time of grafting.

It was always a point of debate that whether cartilage graft is superior to fascia graft.Some studies showed better morphological results with cartilage myringoplasty, whichis statistically significant. However, there was statistically no significant difference seen in the hearing levels. (1).

However some studies showed similar results between cartilage and fascia myringoplasty both morphologically and audiologically. (2)

Differentiation between cartilage and fascia graft is important in the pediatric group, because the eustachian tube has a significant role on the success of myringoplasty.

Two studies show better morphological outcome with the use of cartilage when compared with fascia grafts. (3)Because one of effects of the eustachian tube dysfunction in the pediatric populationis the negative pressure in the middle ear cavity, which can cause retraction of the tympanic membrane with resultant failure of myringoplasty. The effect of this negative pressure can be counteracted by the use of cartilage which is more stiff and resilient when compared with temporalis fascia.

Kazikdas et al and Zahnert et al. Concluded that both tragal and conchal cartilage materials are useful for the reconstruction of tympanic membrane from the perspective of their acoustic properties. Reducing the cartilage size to 500 micrometer is regarded by the authors as a good compromise between sufficient mechanical stability and providing adequate and comparable hearing levels when compared with normal tympanic membrane.

• Tragal perichondrium and fascia lata are thicker and stiffer than temporalis fascia. They are easier to manipulate in the middle ear as they do not get folded on itself, thus have ideal handling qualities.

• However, graft preparation time for tragal perichondrium was longer and fascia lata needed preparing, painting, and draping of a second surgical site increasing the overall time of the surgery.

• Normal translucent appearance of neotympanum in the postoperative period was seen only with temporalis fascia while in tragal perichondrial and fascia lata grafts the neotympanum was whitish, thicker, and translucent to opaque

Cartilage graft techniques

Perichondrium/ Cartilage island flap

Cartilage shield technique

Palisade technique Inlay Butterfly graft

Tragal cartilage Conchal cartilage Tragal cartilage Tragal cartilage Conchal cymba

Tragal Cartilage Harvest – • Cut on posterior surface

of tragus• Leave 2 mm tragal

cartilage for cosmesis• Abundance: 15 x 10 mm• Flat• Approx - 1 mm thickness• Perichondrium is

reflected from the surface of the cartilage.

Perichondrium/ Cartilage Graft

Postop Perichondrium/ Cartilage Island Graft

Cartilage Shield technique : -

• Preferred for total replacement of tympanic membrane.• Less technically demanding and less time consuming.

• Cartilage is harvested and wedge is removed to fit manubrium .• Tight fitting oversized graft should be avoided because of reduction in eventual

vibrational properties.• Concha cymba cartilage has an average thickness of 0.8mm ;its concave

contour resembles the normal shape of TM.• This thickness of cartilage is similar to fossa triangularis and thinner than tragal

cartilage.

Cartilage palisade technique :-

• Curve cymba concha is considered more suitable.

• Useful in posterior perforations associated with ossicular disease.

• Cartilage is sectioned in slices which are then together used to reconstruct TM.

Preparation of slices

Palisade technique intraoperative and postoperative.

Modified palisade technique :-

Cartilage butterfly technique :-

Video

Fat graft myringoplasty :-

• Used to close small perforations.• Fat is harvested from inferior aspect of ear lobule.• Small piece of fat is plugged into the perforation like an hour glass. • Over a time , fat graft adheres and closes the perforation. • Overall success rate – 90- 95 %

Skin graft :-

• Skin area free from hairs and sweat gland is ideally used as graft material e.g. post auricular area , inner surface of arm , deep meatal skin (best for tympanum)

• Skin grafts do not behave well particularly in mastoid segment , the graft sometimes become beefy , may look raw or desqaumate excessively.

• This is d/t presence of glandular elements in skin resulting into recurrent episodes of constant discharge from mastoid cavity.

• Meatal skin will survive well when placed over the tympanum but can cause trouble in mastoid segment.

• Changes associated with skin grafts –1. Choleastetomatous changes 2. Keratosis

Vein graft :-

Fate of vein graft –Endothelium unites with middle ear mucosa , Muscles fibres of tunica media undergo atrophy and replacement fibrosis.Surviving graft is composed of endothelium , elastic and collegeous fibres.

Advantages of vein graft –1. Readily available from varicose clinics2. Sufficient quantity of tissue is available3. No danger of cholesteatoma.4. Hearing results are comparable with other graft materials

Vein graft is stored in clod storage and at the time of operation it is thawed to room temperature before trimming.

Other techniques for tympanic membrane perforation repair

Splintage :-

• Used in fresh traumatic perforations.• Torn edges of perforation are

everted , splinted with absorbable gelfoam within the middle ear through the tear.

• Smaller tears can be splinted on the outer surface with piece of cigarette paper , gel film or silicon sheet.

Cautery patching :-

• Useful in small long standing perforations with epithelised margins.

• Margins of perforation are cauterised with 50 % trichloracetic acid to remove the epithelised edge.

• Perforation is then supported with a cigerette paper moistened with 1 % phenol in glycerine.

• Repeated after 2 weeks interval.

References –

1. Cabra J, Monoux’ A. Efficacy of cartilage palisade tympanoplasty: randomised controlled trial. Otol Neurotol 2010;31:589Y95. Demirpehlivan IA, Onal, K, Aslanoglu S, et al. Comparison of different tympanic membrane reconstruction techniques in Type 1 tympanoplasty. Eur Arch Otorhinolaryngol 2011;268:471Y4 Albirmawy OA. Comparison between cartilage-perichondrium composite ‘ring’ graft and temporalis fascia in type one tympanoplastyin children. J Laryngol Otol 2010;124:967Y74. 2. Yung M, Vivekanandan S, Smith P. Randomized study comparing fascia and cartilage grafts in myringoplasty. Ann Otol Rhinol Laryngol 2011;120:535Y41 Mauri M, Neto JFL, Fuchs SC. Evaluation of inlay butterfly cartilage tympanoplasty: a randomised clinical trial. Laryngoscope 2001;111:1479Y85 3. Ozbek C, Ciftci O, Tuna EE, et al. A comparison of cartilage palisades and fascia in Type 1 tympanoplasty in children: anatomic and functional results. Otol Neurotol 2008;29:679Y83. Albirmawy OA. Comparison between cartilage-perichondrium composite ‘ring’ graft and temporalis fascia in type one tympanoplasty in children. J Laryngol Otol 2010;124:967Y74.

Thank you ….