TYMPANOPLASTY WITH SOFT POSTERIOR MEATAL WALL RECONSTRUCTION: CHANGING THE WAY OF THINKING FOR PREVENTION OF RETRACTION POCKET RECURRENCE
Introduction
There are a few reports of soft posterior wall reconstruction, but no report of tympanoplasty with soft wall reconstruction to prevent post-surgical retraction pocket formation before our short report.1 Smith et al.2 reported reconstruction using a Palva flap and a large piece of fascia, totally obliterating the middle ear and mastoid cavity with Gelfoam. Their purpose was not to prevent post-operative retraction pocket formation, but to simplify reconstruction. We changed our way of thinking and tried to make a soft posterior meatal wall without the aim of fortification but with the aim of preventing post-operative retraction pocket formation.1,3 With our technique, instead of a retraction pocket formation, a balloon-like retraction may occur on the soft posterior meatal wall when there is aeration disturbance of the middle ear. The purpose of this study was to assess the effectiveness of our surgical method for the prevention of retraction pocket formation and to study long-term post-operative results pertaining to reconstructed soft posterior meatal wall.
Surgical procedures
After eradication of the lesion by means of canal wall down technique, every effort is made to leave the posterior meatal skin as intact as possible in order to preserve the original cylindrical shape of the external auditory canal. Myringoplasty is performed using one end of the fascia sheet, and the posterior wall is reconstructed by gluing the other end of the fascia sheet to the reverse side of the peeled-off posterior meatal wall skin with fibrin adhesive1,3 (Fig. 1).
Fig. 1. Surgical procedures. Following the elevation of the meatal skin from the posterior bony wall, the bony wall is removed. This is followed by eradication of the lesion in the middle ear. The posterior meatal skin should be as intact as possible in order to keep original cylindrical shape of the canal. Myringoplasty is performed using one end of a fascia sheet, and the posterior meatal wall is reconstructed by gluing the other end of this fascia sheet to the reverse side of the peeled-off posterior meatal skin using fibrin adhesive.
Subjects of this study were 322 patients with unilateral cholesteatoma who were treated using this method of tympanoplasty between October 1989 and February 2011 and followed up more than fifteen months.
Observation was to determine whether or not the post-operative retractions in narrow-neck pockets occurred and what kind of changes occurred on the reconstructed soft posterior meatal wall. Since we observed that a balloon-like retraction occurred in some patients, the degree of retraction on the soft posterior meatal wall in each case was investigated by calculating the ratio of the volume of the post-operative external auditory canal and the canal on the normal side. The volume was measured by pouring water into the external auditory canal (Fig. 2A,B).
Fig. 2. Method of calculating the degree of retraction. Scheme for explaining the method of calculating the ratio of the volume of the post-operative external auditory canal and canal of the normal side. Volume is measured by pouring water into the external auditory canal. A: normal side; B: post-operative balloon-like retraction.
Results
None of the patients manifested retraction pocket formation, and whenever changes occurred on the soft posterior meatal wall, a balloon-like retraction was observed (Fig. 3A,B).
Fig. 3. Postoperative retraction due to postoperative middle ear aeration disturbance. A Hard wall: When the hard material is used for the posterior meatal wall reconstruction, negative pressure acts to form the retraction pocket which would lead cholesetatoma to recur. B Soft wall: When the wall is reconstructed with a soft material, negative pressure acts on the entire posterior meatal wall and pushes back the whole wall. Retraction cholesteatoma may not recur in such a balloon-like retraction wall.
Judging from the change in the ratio of the volume over time, retraction of the posterior meatal wall appears to occur mainly within one year of surgery.
Figure 4 shows the relationship between the degree of retraction of the posterior meatal wall at the final observation of each patient and the number of ears affected. Regarding the X axis, the larger the ratio of volume, the larger the degree of retraction. ‘The ratio of the volume is 1.0’ means no retraction. The soft posterior meatal wall was maintained in a normal position in 27 ears in which the ratio of the volume was 1.0. The remaining ears had various degrees of balloon-like retraction. However, in the majority of these cases, the degree of retraction was within the ratio of 2.0.
Fig. 4. Number of ears and degree of retraction of the posterior meatal wall at the final observation (322 cases).
Discussion
All other methods of tympanoplasty with canal wall up or canal reconstruction are performed based on the idea of fortification of the posterior meatal wall for prevention of retraction pocket recurrence. Changing this way of thinking, I could avoid the retraction pocket formation. What I would like to underline here is not the material of posterior meatal wall reconstruction but the way of thinking for prevention of cholesteatoma.
With this technique, instead of retraction pocket formation, a balloon-like retraction occurs on the soft posterior meatal wall when there is aeration disturbance of the middle ear, which prevents the recurrence of cholesteatoma.
In comparison to the mastoid obliteration technique, this method also has advantages. Mastoid obliteration is difficult to perform in patients with intracranial complications and metabolic disorders, such as diabetes mellitus. In addition to a wider range of applications, our method allows for easier exposure of residual cho-lesteatoma, and dry ears can be obtained in a shorter post-operative period.
After our previous papers,1,3,4 some papers concerning soft wall reconstruction were publishued.5,6 The number of ear surgeons who adopt this method is now increasing in Japan. I hope this way of thinking becomes widely used in the world.
References
1.Hosoi H, Murata, K. Tympanoplasty with reconstruction of soft posterior meatal wall for prevention of a retraction pocket formation. Otology Japan 2:456, 1992
2.Smith PG, Stroud MH, Goebel JA. Soft-wall reconstruction of the posterior external ear canal wall. Otolaryngol Head Neck Surg 94:355–359, 1986
3.Hosoi H, Murata K. Tympanoplasty with reconstruction of soft posterior meatal wall in ears with cholesteatoma. Auris Nasus Larynx 21:69–74, 1994
4.Hosoi H, Murata K, Kimura H, Tsuta Y. Long-term observation after soft posterior meatal wall reconstruction in ears with cho-lesteatoma. J Laryngol Otol 112:31–35, 1998
5.Takahashi H, Hasebe S, Sudo M, Tanabe M, Funabiki K. Soft-wall reconstruction for cholesteatoma surgery: reappraisal. Am J Otol 21:28–31, 2000
6.Haginomori S, Takamaki A, Nonaka R, Takenaka H. Residual cholesteatoma: incidence and localization in canal wall down tympanoplasty with soft-wall reconstruction. Arch Otolaryngol Head Neck Surg 134:652–657, 2008
Address for correspondence: Hiroshi Hosoi, hosoi@naramed-u.ac.jp
Cholesteatoma and Ear Surgery – An Update, pp. 47–49
Edited by Haruo Takahashi
2013 © Kugler Publications, Amsterdam, The Netherlands