TORP Versus PORP in Austin Type A Ossicular Defects: Which is the Right Choice?

Abstract

Ossicular defects due to chronic ear disease are common and continuous problem for otologic surgeon. Ossicular reconstruction prostheses are widely used to restore ossicular continuity when the incus is eroded or missing, for example, in chronic otitis media or cholesteatoma. In this regard; the total and partial ossicular replacement prosthesis (TORP and PORP) have been enthusiastically endorsed. Traditionally, either PORP or TORP is applicable, depending primarily on whether there is an intact stapes superstructure or only a stapes footplate. Laser interferometer studies on the mechanics of the reconstructed human middle ear have shown that, from a mechanical viewpoint, the malleus to footplate type of reconstruction gives a more favourable result compared with a malleus to stapes superstructure reconstruction even in presence of intact stapes suprastructure. However, it is still unclear whether ossicular reconstruction has a better long-term outcome with PORP or TORP in the presence of stapes suprastructure. A prospective randomised trial of 60 patients with Austin type A defects divided into two groups was conducted. In one group TORP was used and in other group PORP. Outcomes were studied in terms of hearing gain, AB gap closure and stability of the prosthesis. Preoperative PTA of Moderate Conductive Hearing loss (40-55 db) was most found followed by severe conductive hearing loss (> 55 db) with standard deviation of 7.155 and mean hearing loss was 46.30 db in TORP group. In this group post operative pure tone averages improved to mild hearing loss (26-30 db) in about 90 percent of patients with mean of 32 db and standard deviation of 7.06. Preoperative PTA of severe Conductive Hearing loss (> 55 db) was most found followed by moderate Conductive Hearing loss (45-55 db) with standard deviation of 6.471 and mean hearing loss was 47 db in PORP group. Post operative Pure Tone averages improved to Mild Hearing loss (26-30 db) in about 90 percent of patients with mean of 33 db and standard deviation of 5.431 in PORP group. ABG reduction in TORP group was 22.603 ± 12.34 while in PORP group was17.79 ± 10.743. Hearing gain and ABG closure is almost comparable with both TORP and PORP, however because of increased stability of TORP we recommend TORP for better long-term outcomes in Austin type A ossicular defects.