The Collagen Structure of the Tympanic Membrane

Abstract

To analyze the distribution of 3 collagen types in healthy tympanic membranes, during healing of a perforation, and during infection. Design: Immunohistochemical study of collagen types I, II, and III in the tympanic membranes of healthy rats as well as during healing of a perforation and in the presence of infection with Streptococcus pneumoniae at various time points. Setting: Laboratory research center at a university hospital. Results: Type II collagen was a main constituent of the lamina propria of the pars tensa, whereas type I collagen was found mainly in the pars flaccida. Collagen types I and III were found at the insertion to the malleus handle and in the loose connective tissue surrounding the main collagen layer of the pars tensa. After myringotomy, collagen types I and III were found at the perforation border and around dilated blood vessels early in the healing phase. During infection, the collagen layer was thickened and stained

Analysis of gene expression profiles in tympanic membrane following perforation using PCR Array in rats—Preliminary investigation

“…After myringotomy at the perforation border collagen II was not detected, while abundance of collagen types I and III was found in the healing area [21]. In our studies up-regulation of a1 chains of collagen I, III and IV was also revealed and was accompanied by the high expression of genes for all chains of collagen V. It has been shown that collagen type V is the main constituent of the fetal membranes and placenta and plays the regulatory role in fibril and matrix assembly during the development and growth of tissues [22,23].…”

“…The lamina propria of TM pars tensa is mainly made up of type II collagen, whereas type I collagen is found in the pars flaccida [20,21]. After myringotomy at the perforation border collagen II was not detected, while abundance of collagen types I and III was found in the healing area [21].…”

Fibrinogen-Based Collagen Fleece Graft Myringoplasty for Traumatic Tympanic Membrane Perforation

“…Collagen type I and III are present in the acute healing phase after myringotomy and infection, and the collagen content of the TM is modified during the inflammatory and healing processes [7]. TMP is generally located in the pars tensa.…”

“…For example, muscular fascia, which is commonly used to repair perforated tympanic membrane (TM) tissue during myringoplasty, consists primarily of collagen type I [6]. In addition, collagen types I and III have been found at the perforation border and around dilated blood vessels early in the healing phase after myringotomy in rats [7]. We decided to use the fibrinogen-based collagen fleece as a patch material because it has 1) good tissue affinity, 2) water-proofing properties, and 3) abundant type I collagen.…”

Atropic Tympanic Membrane and Hearing Assessment

“…The mesenchymal cells proliferate. The graft is thinned and possibly degraded and replaced when new collagen is produced [5]. Such a TM is adequate for purpose of conduction of sound [6].…”