COMPARISON OF PRE AND POSTOPERATIVE HEARING RESULTS AFTER CARTILAGE AUGMENTATION TYPE III TYMPANOPLASTY

Abstract

Objective:

To compare the hearing results of cartilage augmentation type III tympanoplasty with canal wall down (CWD) mastoidectomy pre and post-operatively.

Materials and Methods:

It is a prospective, analytical, comparative and longitudinal study carried out from 1st October 2006 to 30th April 2008 in Ganesh Man Singh Memorial Academy of ENT and Head & Neck Studies, Institute of Medicine, Maharajgunj, Kathmandu, Nepal. Patients included were having >5years, both gender and diagnosis of chronic otitis media (squamous) with conductive or mixed hearing loss, needing canal wall down mastoidectomy in which stapes suprastructure present and no mastoid surgery was performed previously. Patients with sensorineural hearing loss and post-operative graft failure were excluded. Analysis of 34 ear surgeries was performed. Cartilage from conchal area and graft from temporal fascia was harvested. Pre and post-operative average air bone gap (ABG) at frequencies 500Hz, 1000Hz, 2000Hz and 4000Hz were compared. The post-operative hearing was assessed in terms of ABG closure.

 Results:

The comparison of pre and post-operative ABG in cartilage augmentation type III tympanoplasty at 500Hz was 46.6dB and 37.9dB (p<0.001), at 1000Hz it’s 39.7dB and 30.1dB (p=0.001), at 2000Hz it’s 29.9dB and 22dB (p=0.003) and at 4000Hz it’s 35dB and 29.2dB (p=0.062). The mean pre and post-operative ABG was 37.4dB and 29.7dB, which was statistically significant (p<0.001). The post-operative ABG ranges from 15-47.5dB. Similarly, the ABG closure was within 30dB in 26 (76%) patients.

Conclusion:

Hearing results after cartilage augmentation type III tympanoplasty showed improvement at individual and mean post-operative ABG and also significant improvement in ABG closure suggesting thin cartilage disc increased the effective vibrating area of tympanic membrane graft but there was a great variation, suggesting possibility of effect of multiple other factors.

Keywords: Air bone gap, canal wall down mastoidectomy, cartilage augmentation type III tympanoplasty, chronic media (squamous)