The Postoperative Outcome of the Cartilage -perichondrium Complex Reconstructed Tympanic Membrane Perforation in Guinea Pig / 听力学及言语疾病杂志

ABSTRACT

Objective To observe the thickness and histologic changes of cartilage -perichondrium complex (CP) and vascular density changes in perichondrium after repairing perforated eardrum .Methods Forty -five male guinea pigs were randomly divided into three groups ,and were used to create left TM perforation .The left cavum conchae cartilage-perichondrium was immediately used to repair the perforation .The observation time for group A was two weeks ,group B was six weeks and group C was twelve weeks .The thickness of the composite was meas-ured before and after the implantation .The histologic changes of implants and the vascular change in perichondri were observed .Results The healing time for the left ear was 3 .8 ± 0 .84 ,and the right ear 7 .2 ± 0 .84 .The thick-ness of the composite for group A increased by 14 .4% (P0 .05) .Group C decrease by 14 .2% (P<0 .05) .After implantation ,the thickness of cartilage in group C was decreased by 34 .2% compared to that in group A (P<0 .05) .At the 2nd week in post -implantation ,the number of vessels within the unit area of fiber -perichondrium was up to 13 .28 ± 2 .49 ,while the above number reached to 7 .71 ± 2 .49 at the 6th week after implantation .The final histological structure of recon-structed tympanic membrane at the 2nd week and 6th week was composed of squamous epithelial layer ,fibrous -perichondrium layer ,cartilaginous layer and mucous layer .The above histological structure at 12th week was com-posed of squamous epithelial layer ,cartilaginous layer and mucous layer .Conclusion The healing time of the recon-structed tympanic membrane is shorter than the time spent on healing on its own .The thickness of the composite in post-implantation in three groups first increased and then decreased compared to that in pre -implantation .The number of blood vessels of fiber -perichondrium in the reconstructed tympanic membrane first increased and then re-duced .The layers of final histological structure of reconstructed tympanic membrane are similar to those of normal tympanic membrane .From the perspective of histology ,the cartilage-perichondrium composite is the suitable ma-terial for repairing tympanic membrane .