Published online by Cambridge University Press: 20 March 2008
‘Over-under’ myringoplasty is a versatile and effective surgical technique for tympanic membrane repair. The main drawbacks are possible trauma to the inner ear, due to manipulation of the malleus, and graft detachment from the apical portion of the malleus during the healing process, with consequent reduction of sound transfer function. To obviate these disadvantages, we have modified the over-under myringoplasty by maintaining anchorage of the tympanic membrane to the umbus.
A total of 78 umbus-anchored over-under myringoplasties were performed from 2004 to 2006 in 63 patients. After elevation of the tympanomeatal flap, the malleus was freed from the tympanic membrane in a superior to inferior direction, up to the region immediately superior to the umbus. A large graft with a radial slit was distended under the tympanic remnants and annulus, and the two tongues were positioned to surround the umbus area and overlapped under a non-perforated portion of the tympanic membrane.
Graft take was obtained in 71 ears (91 per cent). The auditory results showed an average residual air–bone gap of 6.7 dB, which was significantly better (p = 0.04) in comparison to that obtained in ears undergoing traditional over-under myringoplasty (11.9 dB).
Modification of the over-under myringoplasty by anchoring the graft to the umbus preserves both lever and catenary effects of the tympano-ossicular system, reduces traumatising manoeuvres during dissection of the tympanic membrane from the malleus, and yields excellent results in terms of graft take and auditory outcome.