NO MORE MASTOID CAVITIES – OBLITERATE THEM ALL
Introduction
Cholesteatoma surgery has been evolving, with canal-wall-down mastoidectomy, canal-wall-up mastoidec-tomy, small-cavity mastoidectomy, and obliteration, the aim being eradication of the disease, stopping the recurrence, and minimizing the problems caused by the open cavity. There have been various methods used to obliterate like flaps, free grafts, prosthetic materials, all of which have their own advantages and disadvantages. Generally, obliteration is done only for problem cavities.
Method
This is a retrospective study of 170 patients with cholesteatoma who underwent primary or revision mastoidec-tomy and had obliteration done between April 2005 and December 2009, with follow up of at least two years. Patients were reviewed at three weeks, six weeks, three months, six month, and 12 months, and then annually. Following clinical examination, patients have audiograms from month three onwards, and tympanograms done after 12 months. The tympanograms of the operated ear are compared with the patient’s other ‘normal’ ear.
My technique
I use endaural incision with laterally based posterior external auditory ear canal skin flap.
Fig. 1. Skin flap..Stage 1
Fig. 2. Skin flap...Stage 2
Fig. 3. Conchal cartilage
Mastoidectomy is done by the ‘inside-out’ method, resulting in minimum mastoid cavity. The bony external auditory canal is widened.
Fig. 4. Soft tissue.
I
Fig. 5a and 5b. Cartilage and slices.
Fig. 6. Cavity at the end of the operation.
Conchal cartilage is taken and the soft tissue is removed to expose the mastoid bone and then both are saved in saline for later use. All cholesteatoma is removed meticulously and hidden places like facial recess and sinus tympani, anterior attic, are inspected using an oto-endoscope to confirm complete removal of the disease.
Fig. 7. Obliterated cavity.
Fig. 8. Two years post-operatively.
The soft tissue removed earlier is saved in saline is used to fill the mastoid cavity. Cartilage slices are used to fill up the attic region and reinforce the tympanic membrane. Cartilage slices can also be used to cover exposed dura, exposed facial nerve, and any fistula in the semi-circular canal. The soft tissue in the mastoid bowl is also covered with cartilage slices, which is then covered with fascia. At the same time the ossicular chain is reconstructed, either with cartilage or a titanium prosthesis. We place the silastic strips in the external auditory canal, which is packed with BIPP impregnated half-inch ribbon gauze. The dressing is changed in three weeks in an outpatient clinic and the second dressing is removed at the six-week mark.
Outcome measures
The ears were assessed by improvements shown in symptoms, clinical examination, audiograms, and tym-panograms, and as mentioned the patients are seen at the following intervals: three weeks, six weeks, three months, six months, 12 months, and then annually.
Of the 164 patients included in this series, only 21 failed to continue attending the follow up after various intervals, while the remaining 143 patients, had follow up ranging from two to five years at least.
Of the 170 patients, only 164 are included in this study, as we could not get the notes for the remaining six patients.
Table 1 shows the comparison of my results with the UK Otology Audit Database.
Table 1.
It seems that the disease is more advanced in the patients presenting to us, as compared with the National database.
There were no recurrences, and no residual disease seen in any of 164 patients at last review. We have achieved our main aim resulting in dry ears in most of our patients (97 %).
Fig. 9. Outcome comparison of of dry ears with UK Otology Audit Base
Seven patients had granulation tissue up to six months. One child had meatal stenosis. One had infection at three months. One revision mastoid case had post-aural fistula through previous scar. Two patients had epithelial pearls, treated by enucleation.
Fig. 10. Tympanogram – Difference between operated and non-operated ears
All the ears have been self-cleaning, while 58.67 % patients had hearing gain. On tympanometry, ten patients had the same volume auditory canal as the non-operated ear, 81 cases had higher value in the operated ear than the non-operated ear, with a range of 0.1 to 2.8 ml, and an average difference of 0.72 ml. Thirty-three cases had lower value in the operated ear than the other ear, but some of these had previously had a mastoid cavity on the other side.
Discussion
Mosher15 described obliteration in 1911 and T. Palva suggested that mastoid obliteration should be done regularly.1 Since then there have been various methods tried; with musculoperiosteal flaps, free fat or tissue grafts, cartilage and other prosthetic materials like hydroxyapatite granules and ceramics. As mentioned, each method has its own advantages and disadvantages, for example, prosthetic materials are expensive and may be extruded, while musculoperiosteal flaps and free grafts may shrink in size.
The main objective is removal of all the disease with minimal self-cleaning cavity, thus avoiding accumulation of debris.
The main concern after obliteration is residual disease underneath the obliteration material, so meticulous removal of all the disease is a must. Residual disease is more commonly seen in epitympanum or mesotym-panum as shown by Syms2 and Kang3 in all types of mastoid surgery. The obliterating material does not hide the attic and middle-ear disease. Several authors have reported minimal or no residual disease.4–7 In this series there has been no residual disease or recurrence in any case.
The CT scans have been used to monitor residual disease following bone paté or prosthetic material obliterations. Yung found that the residual cholesteatoma were detected through clinical examination while they went undetected by the interval scanning at 12 months.8 However, it has been shown that it is not as useful with soft tissue obliterations. Vercruysee has stated that the benefits of using diffusion-weighted MRI scans may make them more useful in detecting residual disease in soft-tissue obliterations, given the ‘safe, noninvasive, selective, sensitive and comparatively cheap alternative to exploratory staged surgery’.9
To asses the success of obliteration it is essential to assess the volume of the operated ear. The only method we have found in literature to asses the canal volume is described by Ojala, who measured it by filling the bony part of the ear canal with sterile saline solution.10 Our method of comparing the volume of normal ear with that of the operated ear using tympanometry gives objective evaluation. The drawback of this method is that the operated ear canal is wider which requires the use of different sizes of ear pieces for tympanometry.
Autologous cartilage is useful in reconstructing the mastoid cavity due to its strength and non-absorbant qualities.11–13
Reconstruction of hearing is done primarily in every case. Our results have been encouraging with 58% showing hearing gain, which has been comparable with other studies. Furthermore, a study by Dornhoffer showed a significant improvement in quality of life following mastoid obliteration.14
Obliteration should become a part of all mastoid surgery. The technique described here is a simple and cost-effective method of achieving a self-cleaning dry ear, using tissues that are normally removed as part of mastoid surgery. Meticulous surgery is shown to reduce the residual disease, while strengthening the tympanic membrane may help in reducing the recurrence, with minimal complications and consistent overall results.
References
1.Palva T. Mastoid Obliteration, Acta Otolaryngol, Supl 360:152–154, 1979
2.Syms MJ, Luxford WM. Management of cholesteatoma: status of the canal wall. Laryngoscope 113(3)443–448, 2003
3.Kang MK, Ahn JK, Gu TW, Han CS. Epitympanoplasty with mastoid obliteration technique: A long-term study of results. Oto-laryngol Head Neck Surg 140(5):687–691, 2009
4.Yung MW. The use of hydroxyapatite granules in mastoid obliteration. Clinical Ototlaryngol 21(6):480–484, 1996
5.Ramsey MJ, Merchant SN, McKenna MJ. Postauricular periosteal-pericranial flap for mastoid obliteration and canal wall down tympanomastoidectomy. Otol Neurotol 25(6):873–878, 2004
6.Gantz BJ, Wilkinson EP, Hansen MR. Canal wall reconstruction tympanomastoidectomy with mastoid obliteration. Laryngoscope 115(10):1734–1740, 2005
7.Bagot D’Arc M, Daculsi G, Emam N. Biphasic ceramics and fibrin sealant for bone reconstruction in ear surgery. Annals Oto Rhino Laryngol 113(9):711–720, 2004
8.Yung MW, Smith P. Mid-temporal pericranial and inferiorly based periosteal flaps in mastoid obliteration. Otolaryngol Head Neck Surg 137(6):906–912, 2007
9.Vercruysee J, De Foer B, Somers T, Casselman JW, Offeciers E. Mastoid and epitympanic bony obliteration in pediatric Cho-lesteatoma. Otol Neurotol 29(7):953–960, 2008
10.Ojala K, Sorri M, Sipilä P, Palva A. Late changes in ear canal volumes after mastoid obliteration. Arch Otolaryngol 108(4):208–209, 1982
11.Hartwein J, Hörmann K. A technique for the reconstruction of the posterior canal wall and mastoid obliteration in radical cavity surgery. Am J Tol 11(3):169–173, 1990
12.Heermann J. Autograft tragal and conchal palisade cartilage and perichondrium in tmpanomastoid reconstruction. Ear Nose Throat J 71(8):344–349, 1992
13.Chao WY. The feasibility of cartilage graft for mastoid obliteration in cholesteatoma surgery. Chin Med J (Taipei) 65(11):515–516, 2002
14.Dornhoffer JL, Smith J, Richter G, Boeckmann J. Impact on quality of life after mastoid obliteration. Laryngoscope 118(8):1427–1432, 2008
15.Mosher HP. A method of filling the excavated mastoid with a flap from the back of the auricle. Laryngoscope 1911;21:1158–63, 2009
Address for correspondence: Ratnamala V. Kayarkar, Consultant ENT Surgeon, Mid Yorkshire Hospitals NHS Trust, Wakefeld, UK. ratan_kayarkar@yahoo.co.uk
Cholesteatoma and Ear Surgery – An Update, pp. 349–354
Edited by Haruo Takahashi
2013 © Kugler Publications, Amsterdam, The Netherlands