Paediatric small cavity mastoid surgery: second look tympanotomy.

OBJECTIVE: Following surgery for retraction pocket/cholesteatoma there is risk of residual disease, after canal wall up surgery a second look tympanotomy is routinely recommended. After canal wall down (CWDM) surgery this is not routine. In certain situations the senior author recommends second look tympanotomy. This report examines the outcome of this management paradigm applied to small cavity mastoid surgery for children.

METHOD: A retrospective review of small cavity mastoid surgery for children with cholesteatoma or discharging retraction pocket disease. The primary procedure and surgical findings at second look tympanotomy are reported as well as the pre- and 1 year post-operative air and bone conduction thresholds and air-bone gap averaged across frequencies 0.5, 1, 2 and 4kHz and the mean pre- and post-operative bone conduction threshold at 4kHz. A Student t-test was used to compare hearing results.

RESULTS: Forty five were children reviewed at 1 year. Twelve (27%) were recommended second look tympanotomy, of which 10 had surgery; all were free of residual disease. At second look two children had ossiculoplasty performed, four had adhesions divided. Six children had formed a myringostapediopexy after their first surgery. The mean pre-op bone conduction threshold was 6.3dB for those having single stage surgery and 5.6dB for those having a second look and the post-operative thresholds were 7.8 and 10.2dB, respectively. The mean preoperative air conduction threshold was 32.6dB for single stage surgery and 31.1dB for staged surgery and at 1 year 29.2 and 40.8dB. This was a significant difference. After second look, the air conduction threshold was 34.5dB, and not significantly different from those who had single stage surgery. The mean pre-treatment 4kHz bone conduction threshold was 6.3 and 5.6dB for single stage surgery and second look tympanotomy and after surgery, respectively, 9.8 and 14.5dB. These changes are not statistically significant.

CONCLUSION: The small cavity mastoidectomy approach allows meticulous removal of disease from the middle ear and for certain indications second look tympanotomy is recommended. Planned second look tympanotomy has demonstrated excellent early disease control as well as allowing timely management of any pathology affecting the middle ear sound transformation mechanism.