PREVENTIVE MEASURES AGAINST CHOLESTEATOMA RECURRENCE IN CANAL-WALL-UP TYMPANOPLASTY: STAGING THE OPERATION AND CHOICE OF MASTOID OBLITERATION
Introduction
For the last 41 years, the senior author (NY) operated on 1053 new cases of middle-ear cholesteatoma at three institutions, where he followed up all these patients as long as possible. Since he saw the video of the planned staged tympanoplasy for cholesteatoma by Dr. Sheehy, Los Angeles, he has decided to adopt the staged canal-up operation and since 1970 he treated more than 500 fresh cases of advanced middle-ear cholesteatoma with this technique. Improvements of the surgical technique were presented to the international conference on cholesteatoma and mastoid surgery in Tel Aviv in 19811 and in Antalya in 2008.2
Based on the surgical experiences he has come to the conclusion that surgical management of cholesteatoma should satisfy the following four objectives: 1) To restore a normal external ear canal with self cleaning function; 2) To restore an aerated middle ear lined with normal mucosa; 3) To restore socially adequate hearing; and 4) To eliminate all possible causes of recurrence. As these four objectives are interdependent, only a canal-wall-up operation remains as a choice to achieve all four objectives. For this purpose, we have developed the staged canal-wall-up tympanoplasty with or without total mastoid obliteration.
Cholesteatoma recurrence
For a good understanding of the staged canal-wall-up tympanoplasty, we first describe why cholesteatoma recurs. Cholesteatoma recurrence is classified into two types: residual cholesteatoma that arises from a residue of the matrix, and recurrent cholesteatoma that originates from a post-operative retraction pocket.
Residual cholesteatoma
Complete elimination of residual cholesteatoma is not always easy because: 1) A tiny residual matrix is hidden in the area, difficult to observe directly; 2) A tiny matrix buried in the granulation tissue is difficult to identify; and 3) A tiny matrix of open-type cholesteatoma is difficult to differentiate from diseased thick mucosa. In our previous study, 40% of residual cholesteatoma was found in the tegmen of the attic and another 40% in the tympanic sinus and peristapedial area.3 With the aid of oto-endoscopy we must carefully clean these risky areas so as not to overlook even a very tiny residue of the matrix.
Retraction pocket is a precursor of recurrent cholesteatoma. We believe that at least three factors, i.e., chronic inflammation in the middle ear, hypoventilation of the tympanic cavity, and defect of the tympanic scute, are related to the development of a retraction pocket. Once self cleaning in the pocket is inhibited, cholesteatoma recurs. To prevent post-operative retraction pocket, therefore, chronic inflammation in the middle ear must be eliminated, an aerated tympanic cavity with ventilation function must be restored and a smooth and stable tympanic scute must be reconstructed.
Because background factors relating to cholesteatoma recurrence are many and complex in advanced cholesteatoma, we can not eradicate all of them with a one-stage canal-wall-up operation. For this reason, a carefully planned and individualized staged operation is needed to achieve the four operational objectives described above. The staged canal-wall-up tympanoplasty with or without mastoid obliteration as described below is a surgical method we have developed to treat the cases with high risk for recurrence due to destructive extension of cholesteatoma beyond the site of origin into the antrum and mastoid cavity involving the ossicular chain.4,5
Surgical method
The first-stage operation
Through a retroauricular incision along the auricular attachment a transcanal attico-tympanotomy and a transcortical mastoidectomy with posterior hypotympanotomy are carried out. While drilling the mastoid cortex bone paté is collected using a paté collector. To control chronic inflammation in the middle-ear granulation tissue and edematous mucosa in the mastoid antrum are cleaned as much as possible. With the combined transcanal and a transmastoid approach cholesteatoma is eliminated totally, together with the malleus and incus, as shown in Figure 1. Oto-endoscopic inspection of the total hidden area is important to minimize the risk of recurrence due to residual cholesteatoma. A sufficiently large silastic sheet of 0.3 or 0.5 mm in thickness is cut in oval shape and folded to insert into the tympanic cavity from the antrum through the aditus ad antrum. As shown in the Figure 2, the lateral side of the folded silastic sheet attaches to the bony edge of the external ear canal and the tympanic membrane to prevent pocket formation. Then the scutum defect is closed by covering over the defect with a plate of bone paté mixed with fibrin glue (Fig. 3). Using a piece of the temporalis fascia, the tympano-meatal defect is closed with an underlay technique. The defect of the mastoid cortical bone is closed using a plate of bone paté hardened with fibrin glue (Fig. 4).6 Then the retro-auricular wound is closed.
Fig. 1. With the combined transcanal and transmastoid approach, cholesteatoma and diseased tissue are removed, together with the malleus and incus. Through the wide posterior hypotympanotomy opening the attic and tympanic sinus must be carefully cleaned not to miss residual cholesteatoma. The superstructure of the stapes is missing in this case.
The procedures illustrated in Figures 2, 3 and 4 are important to facilitate aeration of the middle ear and to prevent post-operative retraction of the ear drum.
Fig. 2. A sufficiently large silastic sheet of 0.3 or 0.5 mm in thickness is cut in oval shape. The sheet is folded and inserted into the tympanic cavity from the antrum through the aditus ad antrum.
Fig. 3. View after the scutum plasty. Bone paté mixed with fibrin glue is pasted over the silastic sheet to close the scutum defect.
Fig. 4. View after the mastoid cortex plasty. Using a bone paté plate hardened with fibrin glue, the defect of the mastoid cortical bone is closed. The tympanomeatal defect is closed with a piece of temporal fascia by an underlay technique.
Timing of the second-stage operation and choice of mastoid obliteration
The second-stage operation is performed one year after the first operation. A year of interval is needed for the following reasons: 1) Residual cholesteatoma, if any, grows to an appropriate size to remove easily and completely; 2) Chronic inflammation in the middle ear cures; 3) The middle-ear cavity is lined by mucosa and aerated. To assess healing of the middle ear and the grade of aeration, computed tomography (CT) of the temporal bone is indispensable.
The middle-ear aeration is graded as follows: Grade 1, only the mesotympanum is aerated; Grade 2, the entire tympanic cavity, including the attic, is aerated; Grade 3, the tympanic and mastoid cavities are aer-ated.7 Total mastoid obliteration is indicated for ears in which aeration is limited to the mesotympanum and attic (grade 1 and 2), whereas canal-wall-up tympanoplasty without mastoid obliteration is chosen for ears with grade-3 aeration.
Through the retro-auricular incision along the scar from the first operation, the reconstructed mastoid cortex is exposed and drilled out to open the mastoid cavity. Bone paté is collected again using a paté collector.
Canal-wall-up tympanoplasty without mastoid obliteration
In the well-aerated middle ear of grade-3 aeration, regenerated mucosa around the silastic sheet is thin and the mastoid antrum is aerated. The silastic sheet is pulled out of the tympanic cavity without difficulty and the aerated tympanic cavity is widely accessible through the hypotympanotomy opening. With the transcanal approach, the scutum reconstructed in the first operation is recruited with a piece of auricular cartilage. The ossicles are reconstructed using either a partial or a total ossicular replacement prosthesis (Fig. 5). The mastoid cortex plasty is carried out to keep good middle-ear aeration using bone paté.6,7 Finally, the retro-auricular wound is sutured.
Fig. 5. With transcanal approach, the scutum reconstructed in the first operation is recruited with a piece of auricular cartilage. The sound conduction system is reconstructed, using either a partial or a total ossicular replacement prosthesis. In this case TORP is used and a piece of cartilage is inserted between the top and the tympanic membrane.
Canal-wall-up tympanoplasty with mastoid obliteration
In the poorly-aerated middle ear of grade-1 or grade-2 aeration the regenerated mucosa around the silastic sheet is thick and little air space is observable in the middle ear. The thick, edematous mucosa in the mastoid and antrum is removed together with the silastic sheet and the narrow air space in the tympanum is opened. The scutum and the ossicules are reconstructed as shown in Figure 5. Then the mastoid cavity is obliterated completely in the following way: 1) Using fibrin glue, two or three small pieces of auricular cartilage are glued to the posterior external ear canal from behind to block communication between the antrum and tympanic cavity (Fig. 6); 2) The antrum is obliterated with bone paté. When there is insufficient bone paté, hydroxyapatite granules can be added to obliterate the cavity (Fig. 7). Finally, the rest of the mastoid cavity is obliterated completely with bone paté to reconstruct the mastoid cortex5 (Fig. 8) and the retro-auricular wound is closed.
Fig. 6. Using fibrin glue, two or three small pieces of auricular cartilage are glued to the posterior external ear canal from behind to block communication between the antrum and tympanic cavity.
Fig. 7. The antrum is obliterated with bone paté. When there is insufficient bone paté, hydroxyapatite granules can be added to obliterate the cavity.
Fig. 8. The rest of the mastoid cavity is obliterated completely with the bone paté plate to reconstruct the mastoid cortex.
Results
Between December 1995 and November 2006, we have performed the staged canal-wall-up tympanoplasty on 80 new cases with advanced cholesteatoma. All cases were followed up as long as possible more than a year after the second-stage operation. No post-operative complications such as ear drum perforation, infection, otorrhea and extrusion of the ossicular prosthesis has been noted in any one of the 80 ears. In 20% of the ears a small residual cholesteatoma was found at the second-stage operation, but was removed easily as a pearly mass. Thanks to the staged procedure none of the 80 ears had residual cholesteatoma at the last follow-up examination.
Table 1. Demographic data of the patients.
Obliteration | No Obliteration | |
(n=27) | (n=21) | |
age (yrs) | 46.3±15.0 (8–68) | 36.6±21.8 (10–71) |
gender | M:10, F: 17 | M: 13, F: 8 |
numbers of age <15 years | 1 | 8 |
Among the 80 cases we have completed follow-up examinations with otomicroscopy and otoendoscopy and a temporal bone CT in 48 cases (60%), 27 cases with mastoid obliteration and 21 without mastoid obliteration, for longer than five years after the second operation. Table 1 shows demographic data of the two groups of the patients. As to post-operative retraction pocket we classified eardrum finding into three categories as shown in Figure 9: without retraction pocket, with shallow retraction pocket and with deep retraction pocket. Table 2 summarizes the incidences of the pockets after the second-stage operation with and without obliteration. In total, 65% of the ears had no retraction pocket. They were totally free from fear of recurrence. Twenty-nine percent of the ears had a shallow but stable and self-cleaning pocket. They were also free from recurrence, but continuation of follow-up examinations once or twice a year was advised. Hence 94% of the cases restored trouble-free ears without fear of recurrence. While there was no ear with deep retraction and a result without retraction pocket was obtained more in the ears without obliteration, no statistically significant difference in the incidences of retraction pocket was verified between the groups with and without mastoid obliteration.
In our follow-up study, the incidences of retraction pocket three years and five years after the second-stage operation are the same. This result indicates that post-operative follow up for at least three years is mandatory to assess the surgical outcome.
Fig. 9. Classification of ear drum retraction three years after the second stage operation: no retraction (a); sallow retraction, shallow, smooth, innocent, and did not require cleaning (b); and deep retraction with a crust requiring cleaning (c).
Table 2. Incidence of retraction pocket in the ears with or without mastoid obliteration.
With obliteration | Without obliteration | Total | |
No retraction pocket | 15 (56%) | 16 (76%) | 31 (65%) |
Shallow retraction pocket | 9 (33%) | 5 (24%) | 14 (29%) |
Deep retraction pocket | 3 (11%) | 0 (0%) | 3 (6%) |
Total | 27 (100%) | 21 (100%) | 28 (100%) |
Comment
In this lecture we presented the staged canal-wall-up tympanoplasty that we have developed for the last 40 years aiming to eliminate all possible causes of recurrence of cholesteatoma and to restore a trouble-free ear, keeping the external ear canal intact. The updated surgical measures are described. We strictly limited the indication of the procedures to advanced middle-ear cholesteatoma extending from the attic or the tympanic cavity to the mastoid antrum involving the ossicular chain and destroying the tympanic scute. Careful otomi-croscopic and otoendoscopic examinations and occasionally a CT of the temporal bone were carried out for five years or more after the second operation in 60% of the cases operated on.
In our investigations in 1992, incidence of recurrent cholesteatoma was 40% following a canal-wall-up one-stage operation.8 As a result of improvements of the staged canal-wall-up procedures for the last 20 years,9 we have achieved the purpose of the operation in 100% of the new cases when the middle ear restored good aeration after the first operation. Even in the ears with continued poor middle-ear ventilation we could reduce incidence of deep retraction pocket from 37% to 10% of the ears thanks to the improvement of the staged surgical maneuver and the mastoid obliteration method. The present result shows the effect of the total mas-toid obliteration for tympanic aeration using sliced cartilage flap, bone paté and hydroxyapatite grain on one hand and importance of stable aeration of the tymapanic cavity to prevent post-operative retraction pocket on the other. Still, further study is needed to ameliorate middle-ear aeration and to stabilize it to prevent postoperative retraction pocket formation and eradicate the resultant cholesteatoma recurrence.
Post-operative hearing outcome is another important aspect of the surgery for cholesteatoma. Although it is out of the scope of the present lecture, we would like to mention that staging the operation and mastoid obliteration do not harm the hearing result. Post-operative hearing improvement also largely depends upon post-operative middle-ear aeration and mucosal condition at the second-stage operation.
References
1.Yanagihara N. Surgical treatment of Cholesteatoma: Problems in indications and technique. In: Sade J (ed.). Cholesteatoma and mastoid surgery, pp. 483–490. Amsterdam: Kugler Publications, 1982
2.Hiniohira Y, Yanagihara N, Komori M, Gyo K. Staging of tympanoplasty in cholesteatoma: Does the use of reconstruction techniques regarding the scutum defect and the mastoid cavity influence the staging? In: Özgirgen ON (ed.). Surgery of the ear – current topics, pp. 284–288. Ankara: Rєkmay Publishing Ltd., 2009
3.Gyo K, Sasaki Y, Hinohira Y, Yanagihara N. Residue of middle ear cholesteatoma after intact canal wall tympanoplasty – Surgical findings at one year. Ann Otol Laryngol 105: 615–619, 1996
4.Yanagihara N, Gyo K, Sasaki Y, Hinohira Y. Prevention of recurrence of cholesteatoma in intact canal wall tympanoplaty. Am.J Otol 14:590–594, 1993
5.Yanagihara N, Komori M, Hinohira Y. Total mastoid obliteration in staged canal-up tympanoplasty for cholesteatoma facilitates tympanic aeration. Otol Neurotol 30:766–770, 2009
6.Yanagihara N, Hinohira Y, Sato H. Mastoid cortex plasty using bone paté. Otol Neurotol 23: 422–424, 2002
7.Minoda R, Yanagihara N, Hinohira Y, Yumoto E. Efficacy of mastoid cortex plasty for middle ear aeration in intact canal wall tympanoplasty for cholesteatoma. Otol Neurotol 23:425–430, 2002
8.Gyo K, Hinohira Y , Hirata Y, Yanagihara N. Incidence of attic retraction after staged intact canal wall tympanoplasty for middle ear cholesteatoma. Auris-Nasus-Larynx 19: 75–82, 1992
9.Hinohira Y, Yanagihara N, Gyo K. Improvements to staged canal wall up tympanoplasty for middle ear cholesteatoma. Otolar-yngology-Head and Neck Surgery:137:913–917, 2007
Address for correspondence: Naoaki Yanagihara, yanagihara@takanoko-hsp.jp
Cholesteatoma and Ear Surgery – An Update, pp. 3–9
Edited by Haruo Takahashi
2013 © Kugler Publications, Amsterdam, The Netherlands