Services for ear
Chronic Ear Infection
Principles :
(1) Squamous epithelium must be excised in Toto or Exteriorized.
A Cholesteatoma is an epithelial cyst in the mastoid. The treatment of a cyst is total excision but if complete excision is not possible incomplete excision will result in recurrence so exteriorization (Marsupialisation) has to be done.(2) Endothelium must be excised in toto or interiorized i.e. put into communication with the Eustachian tube.
Unaerated endothelium will secrete mucus as in serous otitis media. If endothelium is buried under the skin lining of an open mastoid cavity, or under the muscle secretion will result in a discharging cavity. In a well-pneumatized mastoid as in invasive cholesteatoma in a child it is impossible to eliminate all the endothelia (perilabyrinthine cells) so an open mastoid cavity or an Obliterative Muscleplasty is not the solution.(3) Va./s Ratio
Squamous epithelium of the ear canal must be adequately aerated. The ratio of volume of air (Va.) circulating in the ear canal to the surface area (s) of the skin of the ear canal must be correct- if not, the skin will repeatedly break down. In an open cavity (canal wall down technique) the Va. can be increased by a meatoplasty or a conchoplasty & the S decreased by an obliteration muscleplasty.(4) Skin can only grow from skin & Endothelium can only grow from endothelium.
Raw area will granulate.Raw area in the ear canal if large must be grafted. Small raw areas can be covered by silastic or teflon sheeting raw areas in the middle ear must be covered with silastic if large or gelfilm if small.
Polypoidal metaplastic mucosa of the promontory must be removed with gelfilm there is no risk of extrusion but it if get absorbed in a few days, adhension will form with silastic there is a 2-3 % risk of extrusion. This risk can be minimized by
- Wash the silastic in acctone
- With my cartilage technique, silastic cannot come in contact with the fascia.
- Purulent sinusity must be treated & caused before tympanosplasty.
Thick silastic to the removed at a 2 nd stage reinforced silastic (dacron mesh) will not curl up with adramcing fibrosis because granulation grow into the dacron mash but in case of extrusion, removal requires surgery.
Over the years surgeons all over the world have had poor hearing results with tympanosclerosis and even world famous authorities who performed direct t.p. at a second stage had upto 10% S-NHL so they advocate closure of the perforation and recommend a hearing aid. Ossicular fixation by tympanosclerosis in large central perforations is common.
The 2 opposing raw areas will unite by fibrous or bony ankylosis so mobilization, however meticulously done, will be followed by refixation. In cases of triple ossicle fixation, manipulation of the stapes is fraught with danger if the stapediovestibular joint is violated at the time of initial surgery. Therefore such cases must always be done in 2 stages.
Any violation of the stapedio-vestibular joint will result in SNHL.
So if the stapes is fixed, a 2-stage operation is required.
In the bilateral case, it also helps to select the side to be done first. We do the side with the better patch test.
Using a mini-endaural incision, an extended cortical mastoidectomy is performed and Tympanosclerosis is cleared from the mastoid, attic and aditus.
Special care is taken to remove the tympanosclerosis deep & anterior to the malleus head & deep to the incus & the fossa incudis.
To facilitate removal of tympanosclerosis deep to the HOM and incus, or if there is a risk of excessive mobilization of the ossicular chain during removal of tympanosclerosis, the incus is removed and placed in saline.
All raw areas are lined with silastic.
If the stapes is mobile, the M/I are bypassed and a 2-cartilage technique is performed. Not a M-S assembly.
If the stapes is fixed, The incus is disarticulated and the malleus head rotated out of the attic on the axis of the tensor tympani and tympanosclerosis is cleaned deep to it. If the incus is normal, it is removed and replaced in its normal anatomic position on a bed of Silastic and gelfoam. If the incus is necrotic, it is removed and reshaped in such a way that the short process resembles the long process and a notch is drilled to articulate with the head of the malleus. This is then articulated with the malleus and the stapes on a bed of Silastic and gelfoam. The perforation is closed by interlay.
The fixed Stapes is always tackled at a second stage. Post-op., tympanometry is done to check adequate ventilation. After 6 months the second stage endomeatal tympanotomy is performed and the superstructure removed with a laser. There is a high incidence of SN loss with direct piston techniques as reported by various authors. Therefore a direc piston technique is NEVER used in Tympanosclerosis cases. A discrete 0.8 mm. Hole is made and a 0.4 mm. Dia. Piston placed with vein interposition, the Causse Technique.
If however it is not possible to create a discrete hole or if the neo-incus does not permit perfect anchor to the piston, a total platinectomy is performed. With a total platinectomy a piston is never used even with vein interposition, as late bulging of the endosteum will cause a perilymph fistula. So, cartilage with vein interposition is used wherein a precisely measured Y-shaped tragal cartilage is cut using the piston measuring jig.
In all cases intra-operative audiometry is performed with a sterile apparatus.
Pure malleus head fixation is dealt with by a small atticotomy & the entire HOM & incus are lined with silastic. The incudo-stapedial joint is disarticulated to prevent damage to the inner ear & then
re-articulated at the end of the procedure. The attic defect is reconstructed be cartilage. Usually otosclerosis involves the stapes or stirrup bone, the third bone of hearing in the middle ear. This bone rests in a small hollow, the oval window, in intimate contact with the inner ear fluids. This bone is attached to its surroundings by an elastic tissue, the stapedio-vestibular ligament, which allows the free vibration of the stapes while preventing the fluids of the inner ear from leaking out. Fixation of this third bone is called stapedial otosclerosis and is usually correctable by surgery. This enjoys a high success rate of over 96%.
Why is it so difficult?
Tympanosclerosis is sub-mucosal so peeling off the plaques leaves raw areas and bare bone.The 2 opposing raw areas will unite by fibrous or bony ankylosis so mobilization, however meticulously done, will be followed by refixation. In cases of triple ossicle fixation, manipulation of the stapes is fraught with danger if the stapediovestibular joint is violated at the time of initial surgery. Therefore such cases must always be done in 2 stages.
Any violation of the stapedio-vestibular joint will result in SNHL.
So if the stapes is fixed, a 2-stage operation is required.
How to warn the patient?
The gelfoam patch test is useful to predict to the patient the possibility of a 2-stage operation if the AC fails to improve when the perforation is closed by a moist piece of gelfoam.In the bilateral case, it also helps to select the side to be done first. We do the side with the better patch test.
Using a mini-endaural incision, an extended cortical mastoidectomy is performed and Tympanosclerosis is cleared from the mastoid, attic and aditus.
Special care is taken to remove the tympanosclerosis deep & anterior to the malleus head & deep to the incus & the fossa incudis.
To facilitate removal of tympanosclerosis deep to the HOM and incus, or if there is a risk of excessive mobilization of the ossicular chain during removal of tympanosclerosis, the incus is removed and placed in saline.
All raw areas are lined with silastic.
If the stapes is mobile, the M/I are bypassed and a 2-cartilage technique is performed. Not a M-S assembly.
If the stapes is fixed, The incus is disarticulated and the malleus head rotated out of the attic on the axis of the tensor tympani and tympanosclerosis is cleaned deep to it. If the incus is normal, it is removed and replaced in its normal anatomic position on a bed of Silastic and gelfoam. If the incus is necrotic, it is removed and reshaped in such a way that the short process resembles the long process and a notch is drilled to articulate with the head of the malleus. This is then articulated with the malleus and the stapes on a bed of Silastic and gelfoam. The perforation is closed by interlay.
The fixed Stapes is always tackled at a second stage. Post-op., tympanometry is done to check adequate ventilation. After 6 months the second stage endomeatal tympanotomy is performed and the superstructure removed with a laser. There is a high incidence of SN loss with direct piston techniques as reported by various authors. Therefore a direc piston technique is NEVER used in Tympanosclerosis cases. A discrete 0.8 mm. Hole is made and a 0.4 mm. Dia. Piston placed with vein interposition, the Causse Technique.
If however it is not possible to create a discrete hole or if the neo-incus does not permit perfect anchor to the piston, a total platinectomy is performed. With a total platinectomy a piston is never used even with vein interposition, as late bulging of the endosteum will cause a perilymph fistula. So, cartilage with vein interposition is used wherein a precisely measured Y-shaped tragal cartilage is cut using the piston measuring jig.
In all cases intra-operative audiometry is performed with a sterile apparatus.
Pure malleus head fixation is dealt with by a small atticotomy & the entire HOM & incus are lined with silastic. The incudo-stapedial joint is disarticulated to prevent damage to the inner ear & then
re-articulated at the end of the procedure. The attic defect is reconstructed be cartilage. Usually otosclerosis involves the stapes or stirrup bone, the third bone of hearing in the middle ear. This bone rests in a small hollow, the oval window, in intimate contact with the inner ear fluids. This bone is attached to its surroundings by an elastic tissue, the stapedio-vestibular ligament, which allows the free vibration of the stapes while preventing the fluids of the inner ear from leaking out. Fixation of this third bone is called stapedial otosclerosis and is usually correctable by surgery. This enjoys a high success rate of over 96%.
There are 4 methods of dealing with mastoid pathology.
The Cholesteatoma is after all an epithelial cyst involving the mastoid. If you can excise a cyst in toto, it is not necessary to exteriorize it. With modern techniques it is possible to excise it totally and perfectly so you do not have to exteriorize the mastoid cavity. After this operation, you get an endothelium-lined air containing closed mastoid cavity as in normal ears. The air containing cavity is a reservoir to guard against Eustachian catarrh and the hearing result is, therefore, not liable to be affected by a cold. However the technique requires a very high order of skill and a lot of painstaking effort. Under high at the same time preserving a thin posterior meatal wall. Arrangements are also made for mastoid aeration using cartilage and silastic sheet to maintain the path of aeration. Unless done perfectly there is a risk of residual or recurrent cholesteatoma. In case of doubtful clearance a second look may be required. In case of a huge invasive cholesteatoma (difficult pathology) or difficult anatomy (low dura or forward lateral sinus) a C. A. T. may be difficult. Instead of struggling in a difficult situation it is better to take down the bridge & reconstruct it. In case of doubtful clearance a second look may be required.
Complete clearance of the disease is easy because of good visualization obtained by lowering the posterior canal wall. I have my own technique using fascia supported by cartilage struts. Silastic sheeting is used to maintain aeration. Combining a tympanoplasty with ossiculoplasty restores hearing.
b. Minimum postoperative care no cavity problems make it ideal for patients coming from long distance.
Advantages of posterior canal wall reconstruction with cartilage :
1. Complete clearance of disease is easy because of good visualization obtained by lowering the bony posterior canal wall.
2. The Reconstructed posterior canal wall is a thin membrane so there is no risk of a retraction pocket (recurrent cholesteatoma) & no risk of a residual cholesteatoma growing undetected as in a C.A.T. In case if for any reasons the path of aeration were to fail, the thin, membranous posterior canal wall would retract outwards & line the cavity.
3. Residual endothelium is aerated down the Eustachian tube.
4. Normal anatomy is simulated; this is ideal for pilots and divers, who are able to carry out their professions.
5. An adequate reservoir of air is preserved in the middle ear & mastoid, and this maintains the hearing result even in spite of recurrent upper respiratory infections.
6. One stage healing-Both hearing restoration & clearance of disease are achieved in one operation which is important in our country, where financial & social restrictions as well as poor travel facilities prevent frequent follow up visits for open carities & second look operation for C.A.T.
7. In Deaf and discharging mastoid Cavities previously operated upon by old techniques of Radical and Modified Radical Mastoidectomy a one stage healing is achieved.
- Exteriorization operation: the classic radical & modified radical mastoidectomy.
- Obliteration: Muscleplasty
- Combined approach tympanoplasty: Air-containing mastoid cavity with preservation of the posterior canal wall & posterior tympanotomy.
- Posterior canal reconstruction.
A. Exteriorization: the classic radical & modified radical mastoidectomy.
In the old days, without the use of an operating microscope, the surgeon could not be sure of complete excision of the cholesteatoma so the mastoid had to be exteriorized. The posterior wall of the ear canal is removed & the skin of the ear canal is incised & turned down over the facial ridge to help line the mastoid cavity, thus removing the barrier between the external ear canal & the mastoid cavity, & exteriorizing it. With this technique, before healing can occur skin has to creep & line the entire mastoid cavity giving rise to granulations & healing by secondary Intention). If infection occurs, hypertrophic granulations may develop over which epithelium will not creep, resulting in secretion of more discharge which accumulates and causes more hypertrophic granulations to develop, till the vicious circle results in a complete breakdown of the whole lining and a persistently discharging mastoid cavity develops. (Fig 4). If any endothelium has not been eliminated (as in a well pneumatized mastoid) when the skin lines the cavity, the endothelium is not aerated so it will secrete mucous which will cause discharge and the same vicious cycle. A large cavity may not be self-cleaning and desquamated epithelium and wax accumulations have to be removed six monthly by an E.N.T. Surgeon. If this is not done, epithelium may break down underneath the wax accumulations, produce granulations and the vicious circle starts again. In the best hands in the world, in 20% of cases the discharge did not stop with this technique. The reservoir of air is absent, so the patient is very susceptible to eustachian catarrh, & an initial good hearing result may be affected by a bad cold & serous otitis media. In short, this operation renders the ear safe from the risk of intracranial complications, but as far as hearing improvement and stopping the discharge are concerned, the results are unsatisfactory.B. Obliterative Technique-Muscleplasty.
- In order to reduce the size of the mastoid cavity, pedicled muscle flaps may be swung in to obliterate the cavity. There are five disadvantages:
- If any epithelium is buried, a cholesteatoma may form underneath the muscle and may burst into the brain.
- If any endothelium is buried ( in well pneumatized mastoid, it may be impossible to remove all the endothelium from perilabyrinthine cell) it will secrete mucus as it is not aerated. The accumulated mucus will cause discomfort & may periodically discharge.
- After some years, parts of the muscle atrophy and retraction pockets may from.
- The reservoir of air in an air containing mastoid is absent, so the patient is very susceptible to Eustachian catarrh and an initial good hearing result may be affected by a bad cold & serous otitis media.
- The healing here also is by secondary intention, as the skin has to creep over the whole muscles mass.
C. Posterior Tympanotomy and Combined Approach tympanoplasty. (C.A.T.) Mastoidectomy with preservation of the posterior wall of the external ear canal-Air containing mastoidectomy techniques.
Magnification the cholesteatoma metrix is completely removed is an intact sac (not piecemeal).The Cholesteatoma is after all an epithelial cyst involving the mastoid. If you can excise a cyst in toto, it is not necessary to exteriorize it. With modern techniques it is possible to excise it totally and perfectly so you do not have to exteriorize the mastoid cavity. After this operation, you get an endothelium-lined air containing closed mastoid cavity as in normal ears. The air containing cavity is a reservoir to guard against Eustachian catarrh and the hearing result is, therefore, not liable to be affected by a cold. However the technique requires a very high order of skill and a lot of painstaking effort. Under high at the same time preserving a thin posterior meatal wall. Arrangements are also made for mastoid aeration using cartilage and silastic sheet to maintain the path of aeration. Unless done perfectly there is a risk of residual or recurrent cholesteatoma. In case of doubtful clearance a second look may be required. In case of a huge invasive cholesteatoma (difficult pathology) or difficult anatomy (low dura or forward lateral sinus) a C. A. T. may be difficult. Instead of struggling in a difficult situation it is better to take down the bridge & reconstruct it. In case of doubtful clearance a second look may be required.
Complete clearance of the disease is easy because of good visualization obtained by lowering the posterior canal wall. I have my own technique using fascia supported by cartilage struts. Silastic sheeting is used to maintain aeration. Combining a tympanoplasty with ossiculoplasty restores hearing.
b. Minimum postoperative care no cavity problems make it ideal for patients coming from long distance.
Advantages of posterior canal wall reconstruction with cartilage :
1. Complete clearance of disease is easy because of good visualization obtained by lowering the bony posterior canal wall.
2. The Reconstructed posterior canal wall is a thin membrane so there is no risk of a retraction pocket (recurrent cholesteatoma) & no risk of a residual cholesteatoma growing undetected as in a C.A.T. In case if for any reasons the path of aeration were to fail, the thin, membranous posterior canal wall would retract outwards & line the cavity.
3. Residual endothelium is aerated down the Eustachian tube.
4. Normal anatomy is simulated; this is ideal for pilots and divers, who are able to carry out their professions.
5. An adequate reservoir of air is preserved in the middle ear & mastoid, and this maintains the hearing result even in spite of recurrent upper respiratory infections.
6. One stage healing-Both hearing restoration & clearance of disease are achieved in one operation which is important in our country, where financial & social restrictions as well as poor travel facilities prevent frequent follow up visits for open carities & second look operation for C.A.T.
7. In Deaf and discharging mastoid Cavities previously operated upon by old techniques of Radical and Modified Radical Mastoidectomy a one stage healing is achieved.
Patient Information on surgery
Tympanoplasty or reconstruction of the middle ear hearing mechanism serves the purpose of rebuilding the ear drum and/or middle ear bones. Unless control of infection is the reason for surgery, tympanoplasty is an elective procedure.Tympanomastoid Surgery in India has to be planned in such a way that patients coming from long distances need not stay for long nor do they need to come back for frequent dressings. A technique has been evolved at our clinic that permits the patient to go back to his hometown the very next day following surgery. He is seen again after six weeks, by which time the ear should be healed.
An excellent result may be expected in over 90% of cases.
Care of the ear while awaiting surgery :
Till the ear drum perforation is repaired, ear plugs are recommended to protect the middle ear from contamination when bathing.A cotton ball should be used to prevent air-borne contamination. This may help to prevent infection and its complications.
The patient should not blow the nose hard when he/she has a cold.
Treatment:
Prophylaxis - early diagnosis and appropriate treatmentControl the infection - evaluate the Tonsils, Adenoids and para-nasal sinuses
Antibiotics - Local and Systemic antibiotics are administered, in accordance with culture and sensitivity reports.
Tympanosclerosis
Patient Information on surgery
All of the above investigations have a role to play in the diagnosis & management of CSOM, but the one investigation which should not be missed & which requires further elaboration is the gelfoam patch test.The gelfoam patch test
PATCH TEST • Good hearing prediction2 stages ( Tympanosclerosis )
• Which side first?
• Better masking efficiency
• Warning for decreased hearing post-op. (in pan-ossicular / stapedial fixation.)
• Salvage Surgery
In addition to the usual investigations, the gelfoam patch test is extremely useful. The audiogram is repeated after closing the perforation with a patch of moist gelfoam. If the ossicular chain is intact & mobile the hearing will improve.
Why not a paper patch test? If the incus is necrosed & the stapes is mobile the paper patch test will show no improvement but the gelfoam patch test will show improvement because the moist gelfoam pushed through the perforation will contact the mobile stapes in the posterosuperior quadrant.
If the gelfoam patch test shows no improvement there is a possibility of coincident stapes fixation, which might require a 2 nd stage stapes surgery, so the patient can be warned in advance.
In bilateral C.S.O.M. it helps in selecting the side to be done first.
In bilateral C.S.O.M., for salvage surgery, we can confidently advise surgery on the side where there is an improvement with the patch in position.
In bilateral severe mixed loss, where inadequate masking is a problem, the increased hearing with the patch in position on the better side gives better masking efficacy and helps to evaluate the cochlear function of the worse ear.
Warning for decreased hearing after the first stage in stapes fixation because the round window path is blocked.
2) Sinus evaluation is essential because post operative autoinflation exercise may cause silastic extrusion if chronic sinusitis is undetected and untreated.
Incision
The various approaches in use are the post-aural & endaural methods. At times in a wide canal where the mastoid pathology is not to be addressed, an endomeatal procedure can also be performed. At our clinic we use the endaural approach almost exclusively.A mini endaural incision is used which extends just half a centimeter above the tragus. By undermining, a mobile window is created, which can be moved on the outer surface of the mastoid & allows access form the attic to the tip.
Advantages:
• The incision is closed by a single sub cuticular catgut stitch so the patients do not have to come back for stitch removal.• The usual post aural incision cuts many nerves so there is pain and stiffness, which may last for many weeks. This tiny incision is almost as painless as a stapedotomy.
• Automatic meatoplasty
• Quick opening & closing.
• No risk of displacing musculoperiosteal flaps when closing.
• No risk of gaping of the post-aural incision or a post aural fistula.
• Direct access to the superior edge of the tragal cartilage (for ossiculoplasty)
• Thin almost invisible scar
Tympanic membrane reconstruction
Tympanic membrane reconstruction is commonly performed using temporalis fascia either by the onlay or underlay technique, although a wide number of materials have been reported in the medical literature.In our hands temporalis fascia is used by the interlay technique i.e. it is placed between the mucosal and fibrous layers of the drum remnant.
Onlay
The fascia is placed on the outer surface of the denuded drum remnant.The Disadvantages of onlay are as follows:
Blunting
Lateralization
Epithelial Cyst formation
Underlay
The fascia is placed underneath the drum remnant.This is the commonest technique in use the world over. The risk of burying epithelium is minimized, & since the anterior annulus is left undisturbed blunting does not occur; however this technique also has its disadvantages, which are:
Residual perforation :
Medialisation of the graft with adhesions to the promontory.
Chronic myringitis.
Tympanosclerosis cannot be cleared from the anterosuperior quadrant.
Interlay This is the technique of choice
The fascia is placed between the fibrous and endothelial layers of the drum remnant. AdvantagesNo Blunting
No lateralization
No Cyst formation
No Residual perforation
No Medialisation
Can clear Tympanosclerosis from the anterosuperior quadrant.
In case the fascia has been used up during previous surgery the temporalis muscle squeezed in a vein press acts equally well. Perichondrium also can be used.
In accordance with modern OSHA regulations we do not prefer to use other materials such as lyophilized dura, bovine/homograft fascia, etc
Ossicular reconstruction
Materials commonly used:Autografts- Bone
Homografts Bone/ossicles/teeth
Alloplasts
Bone Cartilage
Ossicles
Metallic
Non-Metallic
Precious Metals - Gold Platinum Titanium
Steel
Ceramics
Plastics
The materials used for ossiculoplasty should satisfy certain physical & structural characteristics in order to yield a satisfactory hearing result. Over the years a vast number of materials have been proposed, each having its proponents & detractors. It may be mentioned that there is no one ideal method or one ideal technique that can satisfactorily ameliorate all the possible situations. It must be remembered that the ossicles add approximately 25 dB to the hearing. The ossicular reconstruction should be rigid enough to transmit the high frequencies & yet must not be so firm as to allow the footplate to get subluxated into the vestibule when subjected to inward pressure. The ossicular replacement prosthesis should be at right angles to the footplate. A wide surface area should be presented at the drum-ossicular replacement prosthesis interface. It must not have lateral displacement at its junction with the stapes or footplate for fear of losing transmission efficiency. It must have a mass to density ratio equivalent to the natural ossicles. It must have excellent damping properties in order to avoid transmission of unwanted vibrations to the footplate.
In our experience the material best satisfying the above criteria & having other advantages outlined below is tragal cartilage. Tragal cartilage is used with perichondrium retained on both sides. This is important in order to prevent late absorption or weakening as reported by many authors.
We use cartilage techniques in ossicular reconstruction as follows: Stapes Superstructure Present
The usual method of a reconstruction using a PORP or a reshaped ossicle from the Malleus / T. M. to the head of the stapes has 4 disadvantages.
• Extrusion unless a homograft or autograft ossicle has been used. However, interposing cartilage can minimize this.
• Subluxation of 1 edge of the foot plate into the oval window causing a fistula & late S. N. Loss if inward pressure is exerted on the drum or with a swab stick for impacted wax removal because the normal protection of the incudomalleolar joint is lost.
• Displacement- if the malleus is absent an ossicle or a PORP placed on the head of the stapes is unstable & liable to displacement during the healing process unless used at a second stage after the drum has attained a stable position.
• Ankylosis if the ossicle touches a raw area.
The two-cartilage technique described by us is used to overcome the disadvantages. The first cartilage extends from a depression drilled in the inferior annulus to the head of the stapes. The second cartilage extends from the superior annulus to a depression in the first cartilage for pressure contact.
Materials commonly used:
Autografts- BoneHomografts Bone/ossicles/teeth
Alloplasts
Bone Cartilage
Ossicles
Metallic
Non-Metallic
Precious Metals - Gold Platinum Titanium
Steel
Ceramics
Plastics
The materials used for ossiculoplasty should satisfy certain physical & structural characteristics in order to yield a satisfactory hearing result. Over the years a vast number of materials have been proposed, each having its proponents & detractors. It may be mentioned that there is no one ideal method or one ideal technique that can satisfactorily ameliorate all the possible situations. It must be remembered that the ossicles add approximately 25 dB to the hearing. The ossicular reconstruction should be rigid enough to transmit the high frequencies & yet must not be so firm as to allow the footplate to get subluxated into the vestibule when subjected to inward pressure. The ossicular replacement prosthesis should be at right angles to the footplate. A wide surface area should be presented at the drum-ossicular replacement prosthesis interface. It must not have lateral displacement at its junction with the stapes or footplate for fear of losing transmission efficiency. It must have a mass to density ratio equivalent to the natural ossicles. It must have excellent damping properties in order to avoid transmission of unwanted vibrations to the footplate.
In our experience the material best satisfying the above criteria & having other advantages outlined below is tragal cartilage. Tragal cartilage is used with perichondrium retained on both sides. This is important in order to prevent late absorption or weakening as reported by many authors.
We use cartilage techniques in ossicular reconstruction as follows:
Stapes Superstructure Present
The usual method of a reconstruction using a PORP or a reshaped ossicle from the Malleus / T. M. to the head of the stapes has 4 disadvantages.
• Extrusion unless a homograft or autograft ossicle has been used. However, interposing cartilage can minimize this.
• Subluxation of 1 edge of the foot plate into the oval window causing a fistula & late S. N. Loss if inward pressure is exerted on the drum or with a swab stick for impacted wax removal because the normal protection of the incudomalleolar joint is lost.
• Displacement- if the malleus is absent an ossicle or a PORP placed on the head of the stapes is unstable & liable to displacement during the healing process unless used at a second stage after the drum has attained a stable position.
• Ankylosis if the ossicle touches a raw area.
The two-cartilage technique described by us is used to overcome the disadvantages.
The first cartilage extends from a depression drilled in the inferior annulus to the head of the stapes. The second cartilage extends from the superior annulus to a depression in the first cartilage for pressure contact.