PREVENTION OF RECURRENT CHOLESTEATOMA: EXCLUSION TECHNIQUES USING TITANIUM SHEETING

Bruce Black

Department of Otolaryngology, Royal Children’s Hospital, Brisbane, Australia

Introduction

Since its inception by Jansen,1 intact-canal-wall (ICW) mastoidectomy has become the treatment of choice for attico-mastoid cholesteatomas by many otologists. The technique seeks to restore the diseased ear back to the near normal anatomical and functional state. Compared with canal-wall-down (CWD)/open-cavity surgery, ICW is, however, often perceived as being more at risk to both residual and recurrent disease. This is partly due to flaws of previous ICW drum and canal-wall repair techniques. These left the ear prone to several forms of recurrent sac formation: through a patent or poorly repaired attic defect; via re-collapse of the pars tensa; through necrosis of the external canal wall.2 Failure to perform routine second stage also leads to residual disease difficulties.

Both ICW and CWD techniques are at risk from drum collapse and residual mesotympanic pearls. CWD encounters open-cavity problems whereas ICW may be troubled by persistent attico-mastoid disease, whether residual or recurrent.

Thus for ICW to be the preferred method, it must be designed to anticipate and overcome these latter problems.

Method

ICW surgery follows several general steps. The first is a trans-canal approach that is the optimal route to the stapes, in order to clear this key site of disease, adhesions, etc. Adequate exposure may necessitate a superficial meatoplasty, an anterior wall drill-back, or a scutum curettage. For the subsequent mastoid and attic exposure the author uses a hairline post-aural incision. A key step is a wide exposure of the zygomatic root that in turn facilitates the best trans-mastoid visualization of the attic. Similar ample exposure is required at second stage to allow re-inspection for small pearls of disease.

Prevention of recurrent disease demands an impenetrable barrier, extending from deep into the zygomatic root, along the plane of the facial nerve into the mastoid tip. To achieve this, fine titanium sheeting (0.125 mm thickness, 99.6% pure, annealed, Goodfellow, http://www.goodfellow.com) is used to line the under-surface of the EAC wall, in part or whole, using an aluminium foil template for precise size and shape

When an attic defect is small, an elliptoid 13–20 mm sheet suffices (Fig. 1). The sheeting may be further supported by a simple U-clip of sheeting for stability.3 To underlay the entire canal wall, the implant is a hemi-ellipse (divided longitudinally), approximately 30 mm x 13 mm wide, twisted to adapt to the canal wall and is fitted into slots cut into the zygomatic root and the mastoid tip.3 Any bony-wall defects are repaired with autograft cartilage inlay grafts.3 The titanium layer supports these grafts in situ. The cartilage inlays also prevent biomaterial contact with the canal squamous epithelium. Thinned areas of bony canal wall may be augmented further with either cartilage shavings or with bone pate, especially the area postero-superior to the pars tensa, where a tortuous canal may be inadvertently excessively thinned during attic access. In larger defect cases, vascular flaps (middle temporal4 or temporalis fascia variants) may be used to cover the grafts to provide greater viability of the site.

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Fig. 1. Closure of a limited attic defect, right side second stage ICW. The sheeting is applied to the underside of the attic defect, to the right, and stabilized by the U-clip (inverted, above). The far anterior attic can be viewed clearly for residual foci.

Results

The technique has been used in 185 attico-mastoid cholesteatoma ICW cases (2007–2011 inclusive). Pars-tensa patterns were present in 38%, attic origins in 44%, the remainder (12%) being combined attic and pars tensa collapse cases.5 Mean follow-up time was 2.5 years.

Cases were complicated by mesotympanic residual disease in 8% and attico-mastoid pearls in 9%. Of these, 30% were smaller than two mm diameter (and thus possibly MRI-invisible) at the 12-month second-stage surgery. Mesotympanic recurrences occurred in 4%. Invaginations penetrated or developed around the reconstructed wall in three cases, corrected at second stage procedures. There were no infections related to the use of the sheeting.

Discussion

Effective ICW surgery counters residual and recurrent disease. Staged surgery is effective in eliminating residual pearls; the author’s experience of persisting residual disease beyond a second stage is confined to only anecdotal cases over forty years experience. However, this necessitates adequate surgical access to the attic at both the first and second stages.

To prevent recurrent pockets, the reconstructed canal wall should resist further erosion and display no gaps or slits through which recurrent sacs may invaginate directly, around, beneath, or over the repaired wall. However, the reconstruction must not obstruct review of the previously cholesteatomatous areas. In recent years obliteration has been proposed in several works as an alternative to ICW, but the detection and management of residual (and recurrent) disease remains controversial. Residual pearls are often small and/or slow growing.6 Obliteration techniques risk these being missed by MRI scans;710 when and how often such scans are required is another difficulty. Revision of ossifying obliteration sites is fraught with problems of distorted landmarks; infection may persist undetected for long periods.

Previous ICW techniques were been troubled by attic retractions if closure of an attic defect was not done routinely, or of closure material was poorly fitted or resorbed. Other problems were related to canal wall resorption.1113 Further difficulties occurred when a pars tens collapse ‘underflanked’ an intact or repaired scutum to enter the attic and beyond.

Other problems arose from the type of wall repairs used. These could be classified as onlay, inlay or underlay techniques. Each had particular difficulties. Onlay repairs were stable, but did not prevent underflanking pockets, and obscured adequate inspection of the deep EAC. Inlay methods were difficult to shape exactly to fit the defect, and were unstable, lacking support. They were also prone to adjacent defects if bony wall resorption occurred. Underlay repairs were likewise unstable, requiring supporting material that obstructed second stage re-inspection. A previously employed hydroxylapatite-plate technique2 overcame many of these problems, but the plates tended to partially occlude the attic, necessitating thinning or removal at the second stage. Sporadic long-term infections occurred, and the plates were too small to adapt to the largest defects. Grote hydroxylapatite wall implants14 were cumbersome in this role and fitted poorly into the attic behind an intact wall.

Conversely, the study method stabilizes the inlay grafts, is durable, adaptable to most situations, and permits best possible re-inspection, as the sheeting is applied closely to the canal wall and thus allows best access to the attic (Fig. 2). Titanium sheeting as above is simple to fashion with heavy scissors. It has excellent biomaterial qualities and can be molded to adapt to the curves of the canal. A template affords an exact fit into retaining grooves, promoting fixation and avoiding small chinks around the sheet edges. As the sheeting is applied closely to the horizontal facial nerve, the repair precludes ‘underflanking’ by pars tensa retractions, further avoided by routine reinforcement of the posterosuperior pars tensa quadrant with a composite graft that also shields the ossiculoplasty site (Fig. 3). The combination provides an effective barrier to invagination.

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Fig. 2. Titanium sheeting used for wall repair. From top left, clockwise: Section used for limited attic defects; Larger section used to ‘underwrap’ the entire EAC wall; Section curved to adapt to the EAC wall; U-clip used to stabilize sheeting if required.

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Fig. 3. Attic and drum repair, post-operative appearances of the attic defect repair and the postero-superior pars tensa composite graft.

Conclusion

ICW is the optimal technique to return best anatomical and functional results from cholesteatoma surgery. The method used must adequately anticipate and prevent the problems of residual and recurrent disease.

The above titanium sheeting technique is presented as a relatively simple, but versatile and reliable method of ICW management.

References

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2.Black B. Prevention of recurrent cholesteatoma: use of hydroxylapatite plates and composite grafts. Am J Otol 13:273–278, 1992

3.Black B. Use of titanium in repair of the external auditory canal defects. Otol Neurol 30:930–935, 2009

4.Black B. The use of vascular flaps in middle ear surgery. Am J Otol 19(4):420–427, 1998

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6.Gristwood RE, Venables WN. Growth rate and recurrence of residual epidermoid. Clin Otolaryngol 1:169–182, 1976

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9.Jindal M, Riskalla A, Jiang D, Connor DS, O’Connor AF. A systemic review of diffusion-weighted MR imaging in the assessment of post-operative cholesteatoma. Otology and Neurotology 32:1243–1249, 2011

10.Stassolla A, Magliulo G, Parrotto D, Luppi G, Marini M Detection of opstoperative relapsing/residual cholesteatoma with diffusion-weighted echo-planar magnetic resonance imaging. Otology and Neurotology 25:879–884, 2004

11.Weinberg J, Sade J. Posterior wall atrophy: a late silent complication of combined approach tympanoplasty. Am J Otol 3:315–317, 1982

12.Weinberg J, Sade J. Postoperative cholesteatoma recurrence through the posterior wall. J Laryngol Otol 85:1189–1192, 1971

13.Sanna M, Gamoletti R, Bartesi G, Jemmi G, Zini C. Posterior canal wall atrophy after intact canal wall tympanoplasty. Am J Otol 1:74–75, 1986

14.Black B. Mastoidectomy elimination. Laryngoscope 105 (Supplement 76):1–30, 1995

Address for correspondence: Dr Bruce Black, 6/101 Wickham Terrace, Spring Hill, Brisbane, Queensland, Australia 4000. bruceblackmd@bigpond.com

Cholesteatoma and Ear Surgery – An Update, pp. 367–370

Edited by Haruo Takahashi

2013 © Kugler Publications, Amsterdam, The Netherlands