Round-window anatomical considerations in intratympanic drug therapy for inner-ear diseases.
Our aim was to elucidate the importance of anatomical aspects in planning local therapies for inner-ear diseases. The study undertakes the anatomical evaluation, from a surgical-approach perspective, of the relationship between the false and true round-window membranes. As our design, we chose a human temporal bone dissection study, for which we used 20 fresh temporal bones. After an exploratory tympanotomy and atticotomy, we drilled the anterosuperior (promontory) edge of the round-window niche until the true round-window membrane was completely exposed. We registered the presence or absence and the extent of the false round-window membranes on the round-window niche. We found false round-window membranes obstructing the round-window niche partially or completely in five temporal bones (25%). Complete obstruction was present in one temporal bone (5%). We found mucoperiosteal folds obstructing the round-window niche partially or completely in a significant proportion of the ears. These anatomical particularities could account, at least partially, for the great variability of the results of intratympanic therapies for inner-ear diseases.
Penha
Rui
R
Department of Otolaryngology, New University of Lisbon, Lisbon, Portugal. np46ab@mail.telepac.pt
Escada
Pedro
P
D006801:Humans; D036502:Infusions, Intralesional / Q000379:methods; D007759:Labyrinth Diseases / Q000188:drug therapy*; D012405:Round Window, Ear / Q000033:anatomy & histology* / Q000473:pathology*; D013701:Temporal Bone