CHOLESTEATOMA SURGERY, THE ENDAURAL APPROACH. WALL-DOWN TECHNIQUE WITH OBLITERATION OF PARATYMPANIC SPACES

S. Kosyakov, V. Korshok, A. Kurlova

Russian Medical Academy of Postgraduate Education, Moscow, Russia

Introduction

Unsatisfactory results found even in cases of radical surgery, many patients presenting with cavities, and further problems: all these made us search for a way to minimize the rate of residual cholesteatoma and recurrence of the disease.

From our point of view, the most understandable definition of cholesteatoma was suggested by Jacques Magnan who said at the 2000 Conference on Cholesteatoma and Middle Ear Surgery in Cannes that cholesteatoma is a case of skin in the wrong place. As we know, cholesteatoma can be congenital or acquired and that about 80% of cholesteatomas are developed from retraction pockets. If some piece of the matrix is left after surgery we call it residual cholesteatoma. Recurrent cholesteatoma occurs when all the specific pathogenic mechanisms are repeated (for example negative pressure in the middle ear – retraction pocket – atelectasis) that finally leads to cholesteatoma of external ear canal.

There are some important features which we must mention to understand and justify our approach better. First of all, the balance of middle-ear pressure. The most sensible and clear scheme was published in the book of B. Ars1 about the chronic otitis media pathogenesis. As such, the anterior-inferior part of the temporal bone is compared with the nose (presence of ciliated respiratory epithelium, mucociliary clearance and so on) and its posterior-superior part is compared with the lungs (alveolar-like structure, rich with superficial vessels). This scheme is very important for a clear understanding of the gas-exchange mechanisms in the middle ear and how its impairment participates in the development of cholesteatoma. In the normal ear, the main gas exchange goes through the blood vessels of the aerated mastoid cavity. In cases of inflammation, the blood flow increases and the pressure of oxygen and nitrogen decreases which leads to an increase of carbon dioxide in the middle-ear cavity and, as a result, to negative pressure. This causes retraction pockets or atelectasis formation, which can be considered as pre-cholesteatoma. The ratio between the volume of the mastoid and the area of the air cells surface in the normal ear is quite large. However, due to inflammation, this ratio decreases, which leads to further reduction of gas exchange. Even several episodes of acute otitis media can lead to a gas-exchange reduction, fibrosis of aerated spaces and predispose to cholesteatoma development. In chronic otitis media with cholesteatoma we usually find a small antrum and poor mastoid pneumatization as a result of inflammation which reduces the middle-ear gas exchange. Recent investigations in molecular biology have revealed the mechanisms of cholesteatoma perimatrix activity which is the main reason of bone resorption.2,3 The perimatrix is rich in blood vessels. In particular, the perimatrix is active in the attraction of osteoclasts and bone resorption under the cholesteatoma. This means that you can always expect bone resorption of the facial-nerve canal, even fistula of the lateral semicircular canal, or resorption of other structures of the middle ear. The evidence of perimatrix activity can be illustrated by the following case of a patient who underwent radical surgery 20 years ago. The surgeon had left a part of the cholesteatoma matrix in the cavity, presumably concluding that this was just skin. Now we know that this was ‘wrong skin’ and it was active. After 20 years, the patient developed a fistula of the lateral semicircular canal and residual cholesteatoma in the radical cavity.

Surgery

Currently there are two main techniques for cholesteatoma surgery: closed technique (wall up) and open technique (wall down). Advantages of the wall-up technique are better hygienic status and better functional outcome. But there are some disadvantages, namely a possibly narrow surgical field (not always), and the need for long-term follow up. This technique is associated with a higher rate of residual disease (about 20%), a higher rate of recurrent disease (about 13%). It is also time consuming. However, there are some published results which demonstrate zero recurrence and low residual rate after the closed technique.4,5 It must be noted that these results were achieved with the obliteration of paratympanic spaces. Advantages of the wall-down technique are a lower rate of residuals (about 7%), a lower rate of recurrence (about 5%) and a wide surgical field. Disadvantages include the need for regular cleaning, a higher infection risk, water intolerance, hearing aid fitting problems, vertigo and decreased functional outcome. The post-operative cavity can be considered as a social stigma.

Even stalwarts of the closed technique have, after years of experience, moved to the open technique (wall down) as a better method. The data presented by the Mario Sanna group in Parma in 2010 proved this point of view. But as we mentioned above, the open technique leads to a cavity with all the associated problems. This is why we suggest a modification of the open technique to the closed.

There are several reasons why we uphold the presented approach. The first reason is the conservative tradition. For a long time, the open technique was the only one that was approved for chronic otitis media surgery with cholesteatoma. This is the result of stable conservative traditions, which depend on the educational level. In many cases, surgeons were only taught to perform the open-technique surgery.

The second reason is chimeras in the patient’s mind. Very often the patient is scared of ear surgery, because the brain is near, or an incision behind the ear must be made. Often they prefer to avoid such dangerous surgery. So the endaural approach is preferable and more easily accepted by the patient, because the patient is more confident that the surgeon will not perform trepanation.

The third reason is geographic. Large regions and consequently great distances which have to be covered give rise to problems with extensive follow up and second-look surgery. When they are far from central hospitals, surgeons naturally tend to concentrate on saving patients lives and consider the patient’s quality of life less important. However, this is not a satisfactory situation.

The fourth reason (the nature of what chronic otitis is) is the creation of the demarcation line around the inflammation, natural obliteration. By and large in chronic ears we find a small antrum and sclerotic mastoid cells. What advantage is there in drilling this solid bone which is not involved in inflammation? As we mentioned earlier, we can usually see the natural obliteration in chronic otitis media with cholesteatoma.

The fifth reason is that we cannot determine the edge of cholesteatoma with a CT scan and in most cases of chronic otitis it is not necessary to open the entire mastoid process. More bone can be left intact. If the surgeon has any doubts during the surgery, he can use an endoscope for inspection of the blind zones.

So taking into consideration the advantages of wall down, obliteration and endaural approach we can do the following.

Endaural approach, endaural incision. It is important not to leave in-situ overhangs over the mastoid cavity and high remnants of the external canal posterior wall. But in the case of endaural approach, if you are planning to obliterate the paratympanic spaces it is possible to leave more bone intact with, of course, the obligatory inspection of the blind zones with an endoscope.

Drilling, open technique. Cholesteatoma removing is produced with simultaneous collection of the bone paté. Closing of the tympanic cavity with the chondro-perichondrial flap is performed with simultaneous ossicculoplasty and paratympanic spaces obliteration with bone paté or bioglass and covering it with the chondro-perichondrial flap (Figs. 1 and 2).

We have been following up our patients for some years and then analyzed the results about residue and recurrence of cholesteatoma. So, from 2009 to 2011, we operated 82 ears (80 patients: 29 females and 51 males). Fifty-five operations (67%) were primary surgery, and 27 operations (33%) were revision and re-operations after surgery by other surgeons. The materials used for obliteration were cartilage (30,9%), bone paté (35,8%), bioglass (23,5%) and both bone paté and bioglass (9,9%). We did not observe any recurrence. The residue of cholesteatoma was diagnosed in three cases (3,7%).

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Fig. 1. Wall-down technique with obliteration.

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Fig. 2. Obliteration of paratympanic spaces with bioglass.

From 2009 to 2012, the total number of operations was 118 (116 patients: 45 females and 71 males). The primary surgery rate was 65,2%, revisions and re-operations were performed in 34,8%. The materials used for obliteration were cartilage (22,8%), bone paté (38,9%), bioglass (17,7%), both bone paté and bioglass (14,4%), both bone paté and cartilage (6%). There were no cases of recurrence. A residue of cholesteatoma was revealed in seven cases (5,9%).

If we have a big cavity with an opening of the middle and posterior fossa and the exposed facial nerve, how to obliterate it? Of course it is possible to use the soft-tissue flaps. But what if you need to revise such an ear? You will have a lot of problems to revise the scars, so it should be a solid obliteration and you should cover the most dangerous structures with pieces of cartilage. They can be landmarks during revision. If we have a big cavity evident in cases of revision surgery after radical surgery, when it is difficult to get enough bone paté we use the ‘bricks principle’. If something goes wrong you can remove the ‘bricks’ of conserved costal cartilage, correct the problem and use the ‘bricks’ again (Fig. 3).

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Fig. 3. Obliteration of a big cavity with cartilage ‘bricks’.

Finally, to control the situation and avoid second-look surgery, we use NON-Epi-DWI protocols which are very sensitive in cases of cholesteatoma.

It is important to note that the endaural approach is not a dogma. The choice of approach and technique is up to the surgeon.

References

1.Ars B. Chronic otitis media: Pathogenesis-oriented therapeutic management. The Hague/Amsterdam: Kugler Publications 2008

2.Sudhoff H, Tos M. Pathogenesis of attic cholesteatoma: clinical and immunohistochemical support for combination of retraction theory and proliferation theory. Am J Otol 21(6):786–792, 2000

3.Sudhoff H, et al. Angiogenesis and angiogenic growth factors in middle ear cholesteatoma. Am J Otol 21(6):793–798, 2000

4.Mercke U. The cholesteatomous ear one year after surgery with obliteration technique. Am J Otol 8(6):534–536, 1987

5.Vercruysse JP, 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

Address for correspondence: S. Kosyakov, serkosykov@yandex.ru

Cholesteatoma and Ear Surgery – An Update, pp. 341–344

Edited by Haruo Takahashi

2013 © Kugler Publications, Amsterdam, The Netherlands