Hearing Loss,Conductive Clinical Trial
Official title:
Comparison of Half-thickness Tragal Cartilage Graft to Temporalis Fascia Graft
The rationale of this study is to find out the surgical outcome and success rates of tragal cartilage and temporalis fascia, subsequently to develop guide line in light of the results of this study for our department as our institute is going to follow one patient in one bed policy in future. The purpose of this study is to compare the graft success rate of cartilage versus temporalis fascia in tympanoplasty type I in our institute, as no such study has been conducted in our province before.
Tympanic membrane is forming lateral wall of the middle ear cleft which separates middle ear
from the external auditory canal. It is made of three layers except in the upper part (Pars
Flaccida). The outer layer of TM (Tympanic Membrane) is made of epithelium; middle layer is
fibrous tissue, while inner layer is mucosal lining. The thickness of TM measures 0.1 mm,
having diameter of 7-10 mm, weighing approximately 14 mg. The function of TM is to assist in
hearing and protection of middle ear from infection. Perforation in tympanic membrane is the
loss in continuity of TM layers. The causes of TM perforation may be trauma like blast,
accident and firearm or infection of the middle ear like acute or chronic suppurative otitis
media. It can also be iatrogenic as in case of placement of grommet for glue ear. The purpose
of Tympanoplasty is to reconstruct TM perforation and restores sound conducting mechanism. In
1955, Zoellner and Wullstein used different types of graft materials for tympanoplasty. Later
Heermann introduced cartilage palisade graft labeled as Simmering Technique. Similarly
Goodhill also introduced first cartilage perichondrium composite graft material. Different
graft materials can be used to close the TM defect. Some of these materials are temporalis
fascia, tragal cartilage, perichondrium and fat. Temporalis fascia and tragal perichondrium
had more anatomic proximity, compliance and translucency. The mode of action of these
biological graft materials is that it provides support for the membrane remnant to
proliferate and heal the defect. The temporalis fascia is thin, translucent and available in
sufficient amount; but due to its close resemblance with tympanomeatal flap in color it may
be displaced unintentionally during handling. However the reported success rate of temporalis
fascia graft in literature varies from 93 to 97%.
On the other hand cartilage is middle ear friendly and survives for comparatively longer time
due to the fact that its nourishment is based on diffusion process. Due to rigid nature of
cartilage it prevents medialization of the graft to promontory in case of severe eustachian
tube dysfunction. Cartilage graft is used in cases of chronically malfunction eustachian
tube, adhesive otitis media, recurrent perforation and large TM perforation. But its demerits
are its thick nature which hinders sound conduction and it is limited availability. The
success rate of the cartilage graft tympanoplasty varies in the literature from 43 - 100%.
Chronic suppurative otitis media is an endemic health problem in our society. The reasons
could be probably low literacy level, communities situated far flung from health facilities,
lack of specialist service to the public in outreach area and inappropriate treatment of the
middle ear infections. Sufficient number of patient suffering from inactive mucosal chronic
otitis media with decreased hearing are presenting to otolaryngology unit. Tympanoplasty is
the surgery of choice for chronic otitis media inactive mucosal type.
Hypothesis is that cartilage graft tympanoplasty is more successful than temporalis fascia
tympanoplasty.
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