RESULTS OF CANAL WALL DOWN TYMPANOPLASTY WITH SOFT-WALL RECONSTRUCTION FOR CHOLESTEATOMA

Seiichi Shinden,1 Koji Sakamoto,1 Fumihiro Ito,1 Takeyuki Kono,1 Takanori Nishiyama,1 Kaoru Ogawa2

1 Saiseikai Utsunomiya Hospital, Utsunomiya, Japan; 2 Keio University, Shinjuku-ku, Tokyo, Japan

Introduction

In cholesteatoma surgery, we use canal-wall-down tympanoplasty with soft-wall reconstruction for almost all cases. This method has the advantages of both canal-wall-up procedures, such as early wound healing, and canal-wall-down procedures, such as good radicality. There is another advantage, which is the relative ease with which this procedure can be performed. Furthermore, an even greater advantage of this procedure is that the soft posterior ear auditory canal skin changes its shape and position according to the residual capacity of the mastoid function of each individual patient after mastoid surgery, and this results in long-term safety and stability of the post-operative condition.

In the present study, we assessed incidence of the residual and recurrent cholesteatomas, postoperative conditions of the soft posterior meatal wall, post-operative aeration of middle ear cavity and hearing outcome.

Subject

The study subjects comprised 104 ears in 99 patients (56 males and 43 females) with acquired middle-ear cholesteatoma who had undergone canal-wall-down tympanoplasty with soft-wall reconstruction from 2004 to 2010.

The patients ranged in age from 15 to 84 years (mean 53 years). All the patients were followed for more than one year after surgery (ranging one year to seven years, mean three years and eight months). In 90 ears, post-operative aeration could be evaluated on CT scans. In 98 ears, post-operative hearing was assessed.

The type of cholesteatoma was attic cholesteatoma in 60 ears, sinus cholesteatoma in 24 ears, recurrent cholesteatoma in 17 ears and residual cholesteatoma in three ears.

Surgical technique

In all patients, canal-wall down and mastoidectomy were carried out, preserving the intact parts of the eardrum and external auditory canal (EAC) wall skin as much as possible. The defect on the eardrum or the posterior EAC wall skin after removal of cholesteatoma was covered (reconstructed) by a piece of temporalis fascia (soft-wall reconstruction). This method results in post-operative separation of the mastoid cavity from the EAC, making it different from the conventional CWD technique which opens the mastoid cavity to the EAC. No hard tissues or materials (e.g., cortical bone or cartilage) were used to reinforce or reconstruct the posterior EAC wall in any of the ears in this study.

At the same time, tympanoplasty was done in all of these ears except six. The ossicular chain was preserved in six ears (type I). In 92 ears, various kinds of columellas (incus, auricular cartilage, or artificial columella) were used for the reconstruction of the conductive system; on the stapes head in 64 ears (modified type III) and on the stapes footplate in 28 ears (modified type IV).

Evaluation

All data obtained from these patients were analyzed retrospectively:

Incidence of residual and recurrent cholesteatomas, crust accumulation.

Post-operative conditions of the soft posterior meatal wall. For analysis, the post-operative conditions of the soft posterior meatal wall were divided into four types according to a retracted extent: normal, slightly retracted, moderately retracted and like a radical mastoid cavity.

Post-operative aeration in the middle ear. Computed tomographic scans (CT) performed more than one year after surgery were used to assess aeration. For analysis, the middle-ear space was divided into five segments: Eustachian tube (ET), hypo-mesotympanum, epitympanum, antrum and mastoid cavity.

Hearing outcomes. Audiometric data were obtained at least 1 year after surgery by calculating the pure-tone average of 0.5, 1, 2kHz. Postoperative air-bone (A-B) gaps were calculated in each case.

Results

Incidence of residual and recurrent cholesteatomas, crust accumulation

Of the 104 ears operated on, seven ears (6.7%) had residual cholesteatomas and three ears (2.9%) had recurrent cholesteatomas, while crust accumulation was observed in five ears (4.8%).

Four residual cholesteatomas and all three recurrent cholesteatomas could be removed at the outpatient clinic, while three out of seven residual cholesteatomas were re-operated. Crust accumulation in five ears need to be removed at the outpatient clinic once every several months.

Post-operative conditions of the soft posterior meatal wall

image

Fig. 1. Post-operative conditions of the soft posterior meatal wall (n = 104).

The soft posterior EAC wall apparently retracted like a radical mastoid cavity in 45 of 104 ears (43.2%), moderately retracted in 48 ears (46.2%), slightly retracted in eight ears (7.7%), but showed no retraction in the remaining three ears (2.9%) (Fig. 1). In none of the ears, a defect or perforation occurred in the soft posterior EAC wall because of infection or necrosis of the graft after surgery.

Post-operative aeration in the middle ear

In 90 ears, post-operative aeration could be evaluated on CT scans. Re-aeration was noted in the mastoid cavity in 30%. The rate of re-aeration was 53% in the epitympanum and 89% in the tympanic cavity. Postoperative conditions of the soft posterior meatal wall were not always correlated with these post-operative aerations in the middle ear.

Hearing outcomes

In 98 ears, post-operative hearing was assessed. At the latest hearing test, the mean air-bone gap was < 15 dB in 63 of 98 ears (64.3%) and < 20 dB in 72 of 98 ears (73.5%). As for the mode of tympanoplasty, numbers of ears showing less than 15 dB of ABG were 48 out of 64 ears (75.0%) with type-III or modified type-III tympanoplasty (interposition of an ossicle or an autogenous auricular cartilage columella between the stapes head and the eardrum or manubrium of the malleus), nine out of 28 ears (32.1%) with modified type-IV tympanoplasty (interposition of an ossicle or an artificial columella between the stapes footplate and the eardrum), and five out of six ears (83.3%) with type I.

Discussion

As advantages of the soft-wall reconstruction method, Smith et al.1 stated early post-operative cure of the wound and its technical ease and little addition to operating time.

Hosoi et al.2,3 have pointed out the low incidence of retraction pocket and recurrent cholesteatoma among ears after surgery by this method. In this study, the incidence of post-operative recurrent cholesteatoma was as low as 2.9%. This incidence is considerably lower than those after surgery by ICWT reported previously.4,5 In three ears, a retraction pocket occurred in the soft posterior EAC wall to be a cholesteatoma in this study. The reason why this retraction occurred in such an extremely narrow portion of the soft wall may be partial vulnerability of the posterior EAC wall or ear drum. This suggests that even the soft-wall reconstruction method is not always perfect for the prevention of post-operative recurrent cholesteatoma.

The incidence of residual cholesteatoma was 6.7 %. This results indicate that the soft-wall reconstruction method may have at least an advantage similar to the canal-wall-down and open method in terms of the low incidence of the residual cholesteatoma.

In the present study, moderate retraction or large retraction like a radical mastoid cavity of post-operative soft posterior meatal wall was observed in more ears than those of previous studies.2,3,6 Takahashi et al.6 reported that the soft-wall reconstruction method let the mastoid cavity decide by itself which way to go (retract or not) after surgery according to its residual ventilatory function (gas exchange function). The reason why we had more retracted soft posterior EAC wall in most cases may be that we could not preserve enough intact mastoid mucosa during the surgery.

In this study, higher incidences of postoperative aeration were observed in the ET and hypo-mesotympanum followed by the epitympanum. This result suggests that post-operative recovery of aeration may begin in the ET and advance to the mastoid cavity through the hypo-mesotympanum, epitympanum, and antrum. The ventilation function of the ET is considered crucial for the post-operative recovery of aeration in the middle ear. Further studies of post-operative middle-ear aeration in relation to pre-operative ET ventilation function are needed.

Some studies have discussed which procedure, CWD and open (no aerated mastoid) or CWU, is beneficial with regard to hearing outcome.713 Tos and Lau7 and Stankovic8 reported better outcomes with CWU tympa-noplasty, whereas several studies indicated no differences in terms of post-operative hearing outcome between these two procedures.913 There are no differences between these two methods and CWD tympanoplasty with SWR, as presented here, in terms of post-operative hearing outcomes.

Conclusion

Canal-wall-down tympanoplasty with the soft-wall reconstruction method is found to be a versatile method for cholesteatoma surgery compared with the canal-wall-down method because of earlier wound healing, whilst it preserves the advantages of the latter method, such as low incidence of residual and recurrent cholesteatomas.

References

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2.Hosoi H, Murata K. Tympanoplasty with reconstruction of soft posterior meatal wall in ears with cholesteatoma. Auris Nasus Larynx (Tokyo) 21:69–74, 1994

3.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 112:131–135, 1998

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8.Stankovic MD. Audiologic results of surgery for cholesteatoma: short- and long-term follow-up of influential factors. Otol Neurotol 29:933–940, 2008

9.Cook JA, Krishnan S, Fagan PA. Hearing results following modified radical versus canal-up mastoidectomy. Ann Otol Rhinol Laryngol 105:379–383, 1996

10.Roden D, Honrubia VF, Wiet R. Outcome of residual cholesteatoma and hearing in mastoid surgery. J Otolaryngol 25:178–181, 1996

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13.Murphy TP, Wallis DL. Hearing results in pediatric patients after canal-wall-up and canal-wall-down mastoid surgery. Otolar-yngol Head Neck Surg 119:439–443, 1998

Address for correspondence: Seiichi Shinden, Department of Otolaryngology, Saiseikai Utsunomiya Hospital, 911–1, Takebayashimachi, Utsunomiya, Japan. seiichi_shinden@saimiya.com

Cholesteatoma and Ear Surgery – An Update, pp. 451–454

Edited by Haruo Takahashi

2013 © Kugler Publications, Amsterdam, The Netherlands