Ossiculoplasty in Difficulty: A Method to Improve Stability of TORP

Kim, Chang Woo; Kim, Sang Cheol; Lee, Won Sang

Abstract

BACKGROUND AND OBJECTIVES
Primary goals of surgery for chronic ear disease are infection control and hearing restoration. When performing ossiculoplasty with total ossicular replacement prosthesis (TORP), it is difficult to keep the prosthesis stable. We intended to establish a method for stabilizing TORP in ossiculoplasty and to evaluate the results of the procedure. SUBJECTS AND METHOD: Thirty nine cases of ossiculoplasty performed between January 2000 and February 2003 were analyzed. The follow-up period was from 6 to 31 months (mean 13.1). The pure tone average threshold of the frequencies of 0.5, 1, 2, 3 kHz was used to evaluate results. The degree of hearing improvement, previous mastoid operation method, disease, and extrusion rate of prosthesis were analyzed. To stabilize the TORP, we made a hole in the tragal cartilage and put the shaft of the prosthesis into the hole. RESULTS: A successful hearing gain was defined as a postoperative air-bone gap of < or = 20 dB. According to this criteria, the success rate was 43.6%. Averages of pre and postoperative air conduction were 57.6 dB and 47.1 dB, respectively. The degree of hearing improvement according to the types of mastoid surgery were 48.1% and 33.3% for intact canal wall mastoidectomy and open cavity mastoidectomy, respectively. Four patients underwent reoperation. The findings were 2 cases of short TORP and 2 cases of empty middle ear space, but prostheses were stable in each case. There was one case of extruded prosthesis (2.6%). CONCLUSION: With our method, TORP was kept stable in the oval window niche. However, for hearing improvement, other factors such as middle ear mucosa status or Eustachian tube function are important and further investigation is needed.