Clin Exp Otorhinolaryngol.  2012 Mar;5(1):23-27.

Mastoid Obliteration with Silicone Blocks after Canal Wall Down Mastoidectomy

• Cho SW
• Cho YB
• Cho HH

Abstract

OBJECTIVES
To evaluate the usefulness of silicone blocks as graft material for mastoid cavity obliteration in the prevention of problematic mastoid cavities after canal wall down mastoidectomies.
METHODS
Retrospective evaluation of 20 patients who underwent mastoid obliteration with silicone blocks between 2002 and 2009 at the Chonnam National University Hospital. The cases consisted of 17 patients with chronic otitis media with cholesteatoma and 3 patients with adhesive otitis media. The postoperative follow-up period was an average 49 months (range, 6 to 90 months). The surgical technique used at our institution composed four major steps: First, the canal wall down mastoidectomy was performed and the middle ear procedure was completed. The silicone blocks were used to fill up the mastoidectomized cavity. Then, a cortical bone pate was used to cover the surface of the silicone blocks. Finally, temporalis fascia and a split musculoperiosteal flap were used to surround the bone pate for reinforcement of the reconstructed canal wall. We examined postoperative success rate and hearing outcomes.
RESULTS
In 19 cases (95%), the reconstructed canal wall maintained a cylindrical shape and the ear drum healed without perforation. In only 1 case (5%), the reconstructed canal wall was destroyed with ear drum perforation. The mean improvement in air-bone gap was about 12 dB (P<0.05), and the mean improvement in air-conduction was about 16 dB (P<0.05).
CONCLUSION
We suggest that silicone blocks could be valuable resources as graft materials for mastoid obliteration after canal wall down mastoidectomies.

Keyword

Cholesteatoma; Silicones; Mastoid; Reconstructive surgical procedures

MeSH Terms

Adhesives
Cholesteatoma
Ear
Ear, Middle
Fascia
Follow-Up Studies
Hearing
Humans
Mastoid
Otitis Media
Reconstructive Surgical Procedures
Reinforcement (Psychology)
Retrospective Studies
Silicones
Transplants
Adhesives
Silicones

Figure

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  Fig. 1 Silicone (Hansbiomed Co., Daejeon, Korea) is soft enough to be cut by scarpel and easy to be designed, but solid enough to exist in the mastoid lifelong.

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  Fig. 2 Schematic figures of operating technique. (A) A canal wall down mastoidectomy is performed for removing of diseases. (B) The epitympanic cavity is obliterated with piecemeal cartilage. (C) Mastoid cavity is obliterated with silicone blocks. (D) Coronal view. Silicone blocks are covered with bone pate and temporalis muscle fascia.

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  Fig. 3 Surgical procedures for mastoid obliteration with silicone blocks and bone pate. (A) After elevation of the anterior-based flap, a canal wall down mastoidectomy is performed. (B) The epitympanic cavity is obliterated with piecemeal cartilage. (C) Silicone blocks are used to fill the mastoid cavity. (D) Silicone blocks are fixed using fibrin glue and covered with bone pate. ★, piecemeal conchal cartilage; ◆, silicone block; ♣, bone pate.

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  Fig. 4 Group A, mastoid obliteration with piecemeal silicone blocks and filling with bone pate. Group B, mastoid obliteration with large silicone block and supplying the deficiency with piecemeal silicone blocks and bone pate. Dotted line, mastoid cavity; ★, piecemeal silicone blocks; ◆, large silicone block.

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  Fig. 5 Postoperative findings after mastoid obliteration (7 months after surgery). (A) Photograph of drum and external auditory canal. Reconstructed posterior wall is well maintained. (B, C) Axial and coronal temporal bone CT scan. The mastoid cavity is well obliterated by the silicone blocks (thick arrow) and bone pate (thin arrow).

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