Functional results of revision canal wall down mastoidectomy

In this retrospective study,we evaluated the preoperative and intraoperative findings and functional results of revision surgery after canal wall down mastoidectomy.We reviewed 34 patients(14 men,20 women;age,17–68 years)who underwent revision canal wall down mastoidectomy from March 2006 to March 2017 in the Department of Otology of the First Affiliated Hospital,Wenzhou Medical University,China.This study was approved by the Ethics Committee of the First Affiliated Hospital,Wenzhou Medical University,China(approval No.2008-05-02A11)on May 2,2008.The possible reasons for previous surgical failures were confirmed by the operative findings and included a narrow auditory meatus orifice(100%),recurrent or residual cholesteatoma(82%),high facial ridge(94%),residual air cells(47%),and labyrinthine fistula(12%).The mean time until achievement of dry ear after surgery was 5.8±2.4 weeks.After a mean 6-month follow-up,the mean postoperative air–bone gap decreased from 33.8±4.8 to 17.1±5.1dB in 30 patients who underwent mastoidectomy with simultaneous tympanoplasty.However,no significant postoperative hearing change had occurred in the other 4 patients with eustachian tube occlusion.All patients were followed up for>24 months with a disease-free dry ear and stable hearing results.The main reasons for lack of dry ears after mastoidectomy were a narrow auditory meatus orifice,recurrent or residual cholesteatoma,high facial ridge,and residual air cells.Early dry ear and hearing promotion are obtainable in most patients using revision canal wall down mastoidectomy.