[Reconstruction of the auditory canal wall with bone chips from the temporal squama--preliminary results]

The canal wall down-technique in cholesteatoma surgery with the creation of an open mastoid cavity offers many disadvantages as prolonged healing time, necessity for periodic cleaning and subsequent infections. Therefore reconstruction of the posterosuperior canal wall is the more and more preferred technique to restore the physiologic anatomy of the external auditory canal without lacking a good surgical exposure to the tympanal and retrotympanal spaces. Cartilage is the mainly used material for this technique, as cartilage is easy to prepare and to fit into the defect with good viability. However, cartilage resorption and retraction is observed increasing the risk for recurrent cholesteatoma. In contrast, by the use of bone chips from the temporal squama a stable and close restoration of the auditory canal wall can be achieved.

In 23 patients (17 attic and 6 sinus cholesteatomas including two recurrences in each group) we have performed an anterior atticoantrostomy with retrograde cholesteatoma removal and reconstructed the posterosuperior wall of the auditory canal with bone chips harvested from the temporal squama by chisels. The bone chips and remaining gaps in the reconstructed wall were covered by bone paté and temporal fascia. In 4 cases the ossicular chain could be conserved (type-1 tympanoplasty [TP]), type-3 TP with PORP was performed in 13 and TORP-TP in 6 cases. The mean follow-up was 12.1 months (range 4 - 34 months). 8 patients had undergone a second-look procedure.

On follow-up all patients showed a good healing of the external ear canal with no graft insufficiency. In one case we observed a slight ear canal narrowing due to bone excess, three patients developed retraction pockets of the attic. Recurrent cholesteatoma was not seen yet. Second-look tympanotomy revealed complete ingrowth of the transplanted bone chips into the surrounding bony structures in all cases. One residual cholesteatoma had to be removed and the canal wall had to be reconstructed again with bone chips. The average postoperative air-bone gap was 7.0 +/- 8.2 dB HL for type-1 TP, 8.6 +/- 3.0 dB HL for PORP-TP (83 % [100 %] of the patients < or = 10 dB HL [< or = 20 dB HL]) and 19.3 +/- 9.2 dB HL for TORP-TP (66 % of the patients < or = 20 dB).

Osteoplastic atticoantrostomy allows adequate anatomic and physiologic restoration of the auditory canal even after extensive cholesteatoma removal. Bone stability may reduce recurrent cholesteatoma. However, due to the underlying impaired tubal function long-time results must be further evaluated.