Reconstruction of hearing when malleus is absent: Torp vs. Homograft tmmi

Abstract

To study the most appropriate ossicular reconstruction of patients with an absent malleus, a comparison was made utilizing a homograft tympanic membrane with attached malleus and shaped incus (TMMI) columella and the alternative use of underlay fascia tympanoplasty with a cartilage covered TORP. Forty-six patients were reconstructed with a homograft TMMI and 38 with cartilage covered TORP and underlay fascia technique; 4.5 years postoperatively, 84% of those patients reconstructed with a homograft TMMI maintained an average A/B gap of 25 dB or better. Though 1 year postoperatively the TORP hearing results were satisfactory, only 18% of the TORP patients maintained a hearing level within 25 dB A/B gap at 4 years postoperatively. Primary causes of failure of the TORP were instability with migration off the stapes footplate, protrusion or extrusion through the TM and finally, long-term softening and bending secondary to biodegradation of the Plastipore. The discouraging long-term hearing results found in the TORP patients in this study confirm similar findings reported in 1982 by Smyth in a 5 year follow-up on 116 TORP patients.