EFFECTIVENESS OF CARTILAGE TYMPANOPLASTY AFTER EROSION OF THE INCUS IN CHILDREN WITH CHOLESTEATOMA

Thileeban Kandasamy, Adrian L. James, Blake C. Papsin, Sharon L. Cushing

Department of Otolaryngology – Head and Neck Surgery, University of Toronto; Hospital for Sick Children, Toronto, ON, Canada

Introduction

Cholesteatoma affects three in 100,000 children worldwide and can result in significant morbidity and mortal-ity.1 This disease can be locally destructive and is one of the most common causes of permanent conductive hearing loss in children secondary to incus erosion and/or removal in cholesteatoma surgery. Therefore, one of the goals of cholesteatoma surgery is the restoration of conductive hearing by reconstruction of the os-sicular chain.

Hearing reconstruction is typically achieved with one or more of many reconstruction techniques which include myringostapediopexy (MS), cartilage myringostapediopexy (CMS), incus interposition (II), or synthetic material (titanium, ceramic, cement). Unfortunately, the literature offers little information regarding which choice of reconstruction is the best for children.

In this paper, we evaluate and compare hearing outcomes in children with erosion or absence of the incus from cholesteatoma and reconstructed with a myringostapediopexy, cartilage myringostapediopexy, or incus interposition.

Materials and methods

A prospective cohort analysis of all consecutive children undergoing cholesteatoma surgery between 2001 and 2012 at Sick Children’s Hospital in Toronto, Ontario, Canada was performed. The procedures were performed by two paediatric otologic surgeons. The study was approved by the research ethics board at the University of Toronto. To be included in the study, an intact-canal-wall procedure was performed and an eroded incus with an intact stapes and handle of malleus was identified intra-operatively. All revision cases and patients with fixed stapes were excluded from the study.

Hearing reconstruction was achieved by a myringostapediopexy, cartilage myringostapediopexy, or incus interposition graft (Fig. 1). The choice of the reconstruction was made at the discretion of the surgeon. Tragal cartilage was used for cartilage myringostapediopexy and temporalis fascia was used for reconstruction of the tympanic membrane.

Four-frequency pure tone average (4PTA) air conduction audiograms (0.5, 1, 2, & 4 kHz) were completed on all patients pre-operatively and one year post-operatively. Serviceably normal hearing was defined as a 4PTA of less than 30dB HL.

Comparisons of means were done using unpaired Student’s t-test for variables with Gaussian distribution, and Mann-Whitney for non-Gaussian variables. Comparison of binomial variables (normal versus abnormal hearing) was done using χ2 analysis. All statistical analysis was performed using SPSS (statistical package version 14.0; SPSS, Inc., Chicago, IL).

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Fig. 1. A: Intra-operative image of a cartilage myringostapediopexy reconstruction. B: Post-operative image (18 months) of a cartilage myringostapediopexy reconstruction. C: Post-operative image of an incus interposition reconstruction.

Results

A total of 76 patients were included in the study: 14 patients with MS, 19 with CMS, and 43 with II (Table 1). No significant differences were found between groups with respect to mean age, sex, percentage of incus erosion, or Mills stage. Pre-operative 4PTA in the MS group (29.5dB) was significantly lower than the II group (36.0dB) (p < 0.05). No difference was found in the pre-op 4PTA between the CMS and II groups.

Table 1. Demographics

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Demograpic data for study groups.The only significant difference was found in the pre-op 4PTA between the MS group and the II groups.

Post-operatively, all groups had a significant change in their one-year 4PTA (Fig. 2). The post-operative 4PTA significantly improved in the CMS group (34dB to 23dB; p < 0.05) and II group (35dB to 26dB; p < 0.05). Interestingly, post-operative hearing significantly worsened in the MS group (26dB to 36dB; p < 0.05). The post-operative 4PTA in the MS group was significantly worse than both the CMS and II groups. No difference was found between the post-operative 4PTA in the CMS and II groups.

The percentage of patients who obtained post-operative normal serviceable hearing (4PTA of less than 30dB) was 21.4% with MS, 78.9% with CMS, and 60.5% with II (Fig. 3). The MS group was significantly worse than both the the CMS and II groups. There was no significant difference between the CMS and II groups (p = 0.2).

Discussion

The challenges related to performing ossiculoplasty in children have been attributed to Eustachian-tube dysfunction, higher rates of recurrent infection, and the associated difficulty controlling middle-ear disease. These factors potentially result in higher rates of extrusion or failure. Unfortunately, the literature offers the surgeon very little in helping choose the appropriate method of reconstructing hearing following cholesteatoma surgery in children. Most studies look at the adult population and few studies in children compare different ossicular reconstructive methods.

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Fig. 2. Pre and post-operative 4PTA in MS, CMS, and II groups. All groups had significantly different hearing after surgery.

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Fig. 3. Percentage of patients who achieved serviceably normal hearing (air conduction 4PTA < 30dB). He MS group percentage was significantly lower than both the CMS and II groups.

Silverstein et al.2 evaluated 192 adults and 18 children looking at notched incus homografts and Plasti-Pore prostheses for reconstruction following surgery for chronic ear disease. Although they did find that both methods achieved good post-operative hearing results, the inadequate sample size in the children group did not allow significant conclusions to be drawn. It was noted that the Plasti-Pore extrusion rate was 17% in children and was advised against.

Iurato et al.3 compared myringostapediopexy to incus/malleus interposition in adults and children and found that myringostapediopexy achieved better air-bone gap (ABG) closure within 10db (81%) when compared to ossiculoplasty (55%). The authors did not stratify the results based on adults and children and, therefore, it is difficult to extrapolate these results to children alone.

Nevoux et al.4 looked at cartilage myringostapediopexy in 268 children following chronic ear surgery and found that 62.2% of patients achieved ABG closure within 20dB. Unfortunately, without a comparison group, it is unclear how this means of reconstruction compares to others.

One study by Daniels et al.5 did compare ossiculoplasty techniques in children: porous polyethylene partial ossicular replacement prosthesis (POPs) and Schuring ossicle cup prosthesis (SOCs). They did show that ABG closure within 10dB was achieved in 77% of POPs and 61% of SOCs at one year. They were not significantly different. Only one extrusion occurred in these groups. Unfortunately, no autologous grafts were evaluated and/or compared in this study.

Although ossicular reconstruction in children remains a secondary goal after establishing a safe, dry, and stable ear, post-operative hearing remains a significant concern to patients, parents, and surgeons. Given the potential for extrusion and failure in children, allografts remain a viable option for hearing reconstruction following cholesteatoma surgery, particularly when the stapes is intact. Our study found that in children with cholesteatoma and incus erosion, cartilage myringostapediopexy and incus interposition did improve postoperative hearing. Myringostapediopexy actually worsened hearing post-operatively.

Conclusions

This evaluation of children with intact stapes following cholesteatoma surgery demonstrated that cartilage myringostapediopexy and incus interposition can improve post-operative hearing. Myringostapediopexy may worsen hearing so should be avoided. As cartilage myringostapediopexy may help prevent recurrent pars tensa retraction following surgery, this has become our preferred method of reconstruction for incus erosion in children with cholesteatoma.

References

1.Nguyen CV, Parikh SR. In brief: cholesteatoma. Pediatr Rev 29(9):330–331, 2008

2.Silverstein H, McDaniel AB, Lichtenstein R. A comparison of PORP, TORP, and incus homograft for ossicular reconstruction in chronic ear surgery. Laryngoscope 96(2):159–165, 1986

3.Iurato S, Marioni G, Onofri M. Hearing results of ossiculoplasty in Austin-Kartush group A patients. Otol Neurotol 22(2):140–144, 2001

4.Nevoux J, Roger G, Chauvin P, Denoyelle F, Garabédian EN. Cartilage shield tympanoplasty in children: review of 268 consecutive cases. Arch Otolaryngol Head Neck Surg 137(1):24–29, 2011

5.Daniels RL, Rizer FM, Schuring AG, Lippy WL. Partial ossicular reconstruction in children: a review of 62 operations. Laryngoscope 108(11 Pt1):1674–1681, 1998

Address for correspondence: Thileeban Kandasamy, Department of Otolaryngology – Head and Neck Surgery, University of Toronto,Hospital for Sick Children 555 University Ave., Elm Wing 6103-A, Toronto, ON, M5G 1X8, Canada. thileep.kandasamy@mail.utoronto.ca

Cholesteatoma and Ear Surgery – An Update, pp. 459–462

Edited by Haruo Takahashi

2013 © Kugler Publications, Amsterdam, The Netherlands