Hyderabad technique of obliteration

Hyderabad technique of obliteration

By Dr.G.V.S Rau, Dr.D.S.Arun Kumar, Dr.S.Krishna Reddy

published in AOI APCON 2009 warangal pg.no.12,13,14

We need a technique of obliteration lasting for life in a patient which is both histo-pathologically proved, and with less chances of rejection.

In the materials and methods described in last five decades, there is no single technique sufficient for huge cavities/extensive disease in huge cellular mastoid bones, especially in children.

Hyderabad technique of obliteration is the best technique to obliterate the cavity in either first stage or second stage in recurrent cases with cavity problems.

Out of the 149 cases performed using this technique in the last ten years, no cavities were noticed and the anatomy of ears is maintained near normal except for slightly wide canal and meatus.

This technique involves natural tissues like:

1. Superior / inferior based musculoperiosteal /periosteal flaps

2. Bone pate

3. Cartilage

4. Korners flap

Size of flaps, quantity of cartilage/bone pate depends on variables like size of the cavity and age of patient.

History

The concept of obliteration was introduced by Mosher way back in 1911.

Aim of the procedure

1. to maintain middle ear space

2. to produce no cavity

3. to make the cavity self-draining

4. to provide good ventilation for the cavity

Types of cavity obliteration

1. Partial – obliterating the mastoid cavity in wall down procedures -Hyderabad technique of obliteration

2. Total – blind sac closure – Rambo’s technique

Materials used for obliteration in general:

1. Local flaps – muscle, periosteum, fascia

2. Free grafts – bone(bone chips, bone pate), diced cartilage, fat, hydroxyapatite crystals

3. Mosher’s flap – superior based post auricular soft tissue flap

4. Krish flap – pedicled temporalis muscle flap

5. Rambo – expanded temporalis muscle flap

6. Hong Kong flap – temporalis fascia

7. Muerman & Ojala flap – sternomastoid muscle

8. Popper – periosteal flap to line the mastoid bowl

9. Palva – modified Poppers flap. The technique uses musculoperiosteal flap, bone chips and bone pate to obliterate the mastoid bowl.

Causes of cavity problem:

1. Narrow external auditory canal

2. High facial ridge

3. Inadequate removal of anterior and posterior buttresses, posterior meatal wall

4. Deep tip

5. Inadequate saucerisation

6. Incomplete exenteration and exteriorisation of disease especially from sinodural angle, facial recess, sinus tympani, peri labyrinthine cells, oval window and hypo tympanum

Indications of cavity obliteration:

1. Debris – in canal wall down procedure (cwd), there is accumulation of cerumen and squamous debris.

2. Discharge – persistent otorrhea indicative of non-healing cavity

3. Deafness and difficulty in using hearing aid.

4. Dizziness from exposure of ear to warm or cool air/water

5. Susceptibility to infections.

6. Complete obliteration in cases of CSF otorrhea, Spontaneous and traumatic meningo encephalocele, 11% cases of post op acoustic neuroma (Trans labyrinthine approach), severe temporal bone fractures.

Special indications:

1. Cochlear implant patients with CSOM

2. Cochlear implantation requiring extensive drill out with removal of posterior meatal wall

3. Canal cholesteatoma causing erosion of external auditory meatus

4. In cases of CSOM with no useful hearing

Procedure in brief:

Approach – post aural approach

Anaesthesia – local/general anaesthesia, preferably under LA except in children and apprehensive patients

Harvesting temporalis fascia – take temporalis fascia of size more than one rupee coin and dry it for grafting

Incisions and flaps to be elevated – depending on availability of canal skin, Korner’s flap elevation is done. Other flaps like tympano meatal flap and any well epithelialized healthy flap covering mastoid cavity are to be elevated.

If there is any discontinuity during elevation, in the flaps, the flap can be treated as a free skin graft and should be preserved in saline which can be used later for reconstruction.

In first stage cases, one must do MRM and clear the disease

In second stage cases, clear the cholesteatoma and granulations from existing cavity

Maintaining middle ear space

Anterior and posterior buttresses removal and the facial ridge lowering will depend on disease, ossicular status and the type of ossiculoplasty you are planning for.

Clearance of the disease

Clear the disease and granulations from attic, sinodural angle, sinus plate, tip of mastoid, supra tubal and supra labyrinthine areas, facial recess, sinus tympani and hypo tympanum.

Saucerisation of cavity

Removal of cells from the root of zygoma, squamous part of temporal bone and the bone covering sigmoid sinus to the level of facial ridge and excision of the tip of the mastoid to make the mastoid cavity shallow.

Conchomeatoplasty

Depending on size of cavity, the technique of conchomeatoplasty will be selected and done. The cartilages removed during this procedure are preserved in sterile saline solution.

Reconstruction

1. Attic reconstruction with conchal cartilage and loose areolar tissue behind concha if cartilage is not sufficient

2. Cavity obliteration – Hyderabad technique of obliteration;

a) Depending on size of the cavity, superior or inferior based musculo periosteal flap is elevated and placed in cavity.

b) Temporalis fascia graft is rehydrated and placed medial to the remnant of tympanic membrane and tympanomeatal flap.

c) Elevate the TM flap along with temporalis fascia as a single unit and place it anteriorly.

d) At this stage ossiculoplasty will be done.

e) Replace the flaps up to the horizontal part of facial nerve superiorly and to the level of facial ridge posteriorly.

f) Attic and facial ridge are reconstructed and augmented with conchal and tragal cartilages harvested during meatoplasty.

g) In between the superior/inferior pedicle flaps and the cartilages, the cavity will be filled up with bone pate. Be careful to prevent bone pate from slipping into middle ear.

h) Replace carefully the tympanomeatal flap with temporalis fascia elevated as a single unit onto the cartilages, bone pate and pedicle flaps

Placement of Korner’s flap:

Depending on the cavity, the Korner’s flap will be cut superiorly / inferiorly and placed on to the temporalis fascia to give strong support to the obliterated material, and to reconstruct the EAC.

Meatal packing:

Packed in 3 layers

1^st layer: gel foam impregnated with sofracort drops

2^nd layer: dry gel foam with Neosporin ointment

3^rd layer: BIPP / soframycin ointment impregnated ribbon gauze pack.

This meatal pack is to be removed only after 3 weeks.

Precautions

• · Care must be taken that the bone pate collected does not contain any cholesteatoma matrix.
• · After saucerisation, irrigate the cavity well to avoid any leftover bone pate/cholesteatoma matrix.
• · Change the gloves before harvesting the cartilage and grafting
• · In revision cases be cautious about exposed dura, sinus and facial nerve while giving the incisions and raising the flaps.

Conclusion

Hyderabad technique of obliteration is the best technique for obliterating huge cavities/extensive disease in huge cellular mastoid bones, especially in children, its main advantages being that it uses natural materials for obliteration which can be obtained from the same incision and it eliminates cavity problems. It can be performed as first stage/ second stage in recurrent cases

Address for correspondence

DR.RAU’S ENT SUPER SPECIALITY HOSPITAL

Behind Durga Malleswara Swamy Temple,

1/2 RT, Housing Board Colony,

Opp.Mosque, Panjagutta,

Hyderabad- 500 082

Ph.no.98490 85060