General Characteristics of Tympanic Membrane Perforations Tympanic membrane perforations are usually present at the pars tensa. Pars flaccida perforations are generally associated with epitympanic cholesteatoma. If a tympanic membrane perforation does not heal spontaneously, the epithelial and mucosal layers creep and meet along the borders of the perforation. This pathological communication between the middle and external ear can be considered a true “air fistula.” In the presence of a tympanic membrane perforation, the patient is subjected to recurrent infections and ear discharge. Whenever tympanic membrane perforations are diagnosed, the following three assessments must be performed: (1) at the level of the perforation, the site, size, and state of the remainder of the tympanic membrane around the perforation should be determined; (2) at the level of the middle ear, the state of the mucosa, the condition of the ossicular chain (if possible), and the presence or absence of epithelialization should be evaluated; (3) the otoscopic examination has to be complemented with pure tone audiometry to obtain a better understanding of the ossicular chain (possible erosion of the incus, fixity of the chain). Pars tensa perforations can be either central or marginal. Marginal perforations lie at the periphery of the tympanic membrane with absence of the fibrous annulus. Marginal perforations are considered “unsafe” because the skin of the external auditory canal, in the absence of the annulus, can easily advance toward the middle ear, giving rise to cholesteatoma. Otoscopic examination can often define the junction between the skin and the mucosa at the borders of the tympanic membrane perforation. At this junction, the squamous epithelium has a “velvety” appearance. The presence of a red de-epithelialized ring along the perforation rim indicates the evagination of the mucosa toward the external surface of the tympanic membrane residue. However, invagination of the skin toward the inner surface of the tympanic membrane residue is more difficult to diagnose. This inward skin migration is favored by the atrophy of the mucosa which occurs as a result of the perforation. At the time of myringoplasty, freshening of the edge of the perforation not only promotes the attachment of the graft but also greatly reduces the risk of leaving entrapped skin on the undersurface of the drum, which may lead to iatrogenic cholesteatoma. Conductive hearing loss caused by tympanic membrane perforation has two main causes: (1) reduction of the tympanic membrane surface area on which the acoustic pressure exerts its action and (2) reduction of the vibratory movements of the cochlear fluids, because sound reaches both windows at nearly the same time without dampening and phase-changing effect of the intact tympanic membrane. The site of the perforation cannot be correlated to a particular audiometric pattern. However, it is generally observed that hearing loss occurs more in the low frequencies and that, for perforations of the same size, hearing loss occurs more in the posterior perforations than in anterior ones. The majority of posttraumatic and postotitic perforations heal spontaneously. When large portions of the tympanic membrane are lost or when chronic or recurrent infections occur, the perforation may become permanent. In these cases, the tympanic membrane must be repaired (myringoplasty) to restore the normal physiology of the ear. These type of perforations have been shown in ▶ Fig. 7.1, ▶ Fig. 7.2, ▶ Fig. 7.3, ▶ Fig. 7.4, ▶ Fig. 7.5, ▶ Fig. 7.6, ▶ Fig. 7.7, ▶ Fig. 7.8, ▶ Fig. 7.9, ▶ Fig. 7.10. Fig. 7.1 Left ear. The tympanic membrane is very thin due to atrophy of the fibrous layer. A posterosuperior marginal perforation is seen. This perforation is risky because the skin of the external auditory canal can easily advance into the middle ear, forming a cholesteatoma. In this case, a myringoplasty using an endomeatal approach is indicated. Fig. 7.2 Left ear. Perforation of the posterosuperior quadrant of the tympanic membrane. Visualized through the perforation are the incudostapedial joint, the stapes, the stapedius tendon, the pyramidal process, the promontory, and the round window. The residue of the tympanic membrane is very thin due to absence of the fibrous layer. Tympanosclerosis can be seen in the marginal part of the drum residue. From the surgical point of view, posterior perforations are the easiest to repair, especially when partial reconstruction of the tympanic membrane is all that is required. When the residue of the tympanic membrane is transformed into a rigid tympanosclerotic plaque, it is advisable to remove it, conserving the epidermal layer to be laid over the graft. Fig. 7.3 Right ear. Large perforation of the posterior quadrants. Normal middle ear mucosa. The incudostapedial joint is intact. The oval window with the annular ligament surrounding the footplate can be seen. The pyramidal eminence, the stapedius tendon, the round window, and Jacobson’s nerve running on the promontory are also visible. The remaining anterior quadrants of the tympanic membrane are tympanosclerotic and rigid, blocking the mobility of the malleus. Fig. 7.4 Right ear. Presence of chronic otitis media. Dry perforation of the posterior quadrants of the tympanic membrane, through which the head of the stapes and the round window are visible. The long process of the incus is necrosed. The middle ear mucosa is normal. The tympanic membrane residue shows tympanosclerosis with alternating areas of calcification and areas of thinned membrane due to atrophy of the fibrous layer. The operation, performed through a postauricular incision, will also include the reconstruction of the ossicular chain using the autologous incus. Fig. 7.5 Left ear. Posterior nonmarginal perforation. The incudostapedial joint, the promontory, and the round window are all discernible. Fig. 7.6 Right ear. Presence of a simple chronic otitis media; a posteroinferior drum perforation. The middle ear mucosa is normal. The round window and Jacobson’s nerve running on the promontory are seen. The incus can also be appreciated posterior to a retromalleolar tympanosclerotic plaque. The tympanic membrane residue shows areas of atrophy alternating with areas of tympanosclerosis. Fig. 7.7 Right ear. Perforation of the posteroinferior quadrant of the tympanic membrane. The anterior quadrants show slight myringosclerosis. The oval window and the promontorium are visible. Middle ear mucosa is normal. In this case, underlay myringoplasty with endocanalar approach is indicated. Fig. 7.8 Left ear. Perforation of the posterior quadrants of the tympanic membrane. The skin advances along the posterosuperior border of the perforation toward the incudostapedial joint. The middle ear mucosa appears hypertrophic. Mucoid discharge is also present. A tympanosclerotic plaque can be seen in the residue of the tympanic membrane. Fig. 7.9 Left ear. Perforation of the posterior quadrants of the tympanic membrane. The perforation borders are irregular with epithelialization toward the middle ear. A small mesotympanic cholesteatoma could be suspected. In this case, retroauricular-approach myringoplasty with mastoid exploration is the treatment of choice. Fig. 7.10 Right ear. Marked posterior marginal perforation through which the skin penetrates into the middle ear. The incudostapedial joint is not visible. These type of perforations have been shown in ▶ Fig. 7.11, ▶ Fig. 7.12, ▶ Fig. 7.13, ▶ Fig. 7.14, ▶ Fig. 7.15, ▶ Fig. 7.16, ▶ Fig. 7.17. Fig. 7.11 Left ear. Small anterior perforation of the tympanic membrane. Hearing function is normal. Surgical treatment of this case depends on patient’s symptoms (i.e., recurrent otorrhea). Anterior hump of the external auditory canal can be seen, preventing total visualization of the annulus. In this case, myringoplasty should be performed with canalplasty. Fig. 7.12 Right ear. Anterior perforation of the tympanic membrane. Middle ear mucosa is normal and the tubal orifice is visible. The rest of the tympanic membrane is tympanosclerotic, resulting in moderate conductive hearing loss (see ▶ Fig. 7.13). In this case, mobility of the ossicles should be checked during the myringoplasty. Fig. 7.13 Audiometry of the previous case. Fig. 7.14 Left ear. Anterior perforation of the tympanic membrane with inferior and posterior extension. The tubal orifice, as well as Jacobson’s nerve and inferior tympanic artery, is clearly visible. Posteriorly, a tympanosclerotic plaque is present. The mass can be confused with a cholesteatoma. Testing the consistency of the mass using an instrument under the microscope could be useful: in case of cholesteatoma, the mass is soft and will break, whereas tympanosclerosis is generally hard. Fig. 7.15 Right ear. Anterior perforation in a patient with anterior and posterior humps of the external auditory canal as well as osteoma of the superior canal wall. In this case, canalplasty should be performed at the same time as myringoplasty. Fig. 7.16 Case similar to that in ▶ Fig. 7.12. Left ear. Dry anteroinferior perforation. The middle ear mucosa is normal. The tympanic membrane residue shows tympanosclerosis, giving it a white appearance. The tubal orifice can be seen from the anterior margin of the perforation. Fig. 7.17 Left ear. Perforations of the anterior quadrants of the tympanic membrane. A small bridge of intact membrane separates the two perforations. The tubal orifice, as well as the supratubal recess and the hypotympanic area, is visible. The malleus handle is amputated with medial epithelialization. A mass similar to a small cholesteatoma is visible medial to the anterosuperior border of the perforation. In this case, careful examination of the middle ear should be performed. These type of perforations have been shown in ▶ Fig. 7.18, ▶ Fig. 7.19, ▶ Fig. 7.20, ▶ Fig. 7.21. Fig. 7.18 Left ear. Small tympanic membrane perforation. The whole tympanic membrane is tympanosclerotic, mainly on its posterior quadrants. Audiometry showed moderate conductive hearing loss, maybe due to ossicular fixation. Even in this case, myringoplasty should be performed with careful inspection of the ossicular mobility. Fig. 7.19 Right ear. Inferior perforation. The posterior and anterior residues of the tympanic membrane show tympanosclerosis. The hypotympanic cells are also visible. Fig. 7.20 Right ear. Anteroinferior perforation. Two tympanosclerotic plaques are observed: one anteromalleolar and the other retromalleolar. The middle ear mucosa is normal. The hypotympanic air cells are seen through the perforation. Fig. 7.21 Right ear. Inferior perforation. Even in this case the rest of the tympanic membrane is tympanosclerotic. The marginal tympanic perforation is unsafe, with epithelialization toward the inner surface of the tympanic membrane and the middle ear. These type of perforations have been shown in ▶ Fig. 7.22, ▶ Fig. 7.23, ▶ Fig. 7.24, ▶ Fig. 7.25, ▶ Fig. 7.26, ▶ Fig. 7.27, ▶ Fig. 7.28, ▶ Fig. 7.29. Fig. 7.22 Right ear. Large tympanic membrane perforation. The tubal orifice, the hypotympanic air cells, the promontory, the round and oval windows, and the intact stapes can be viewed. An onset of necrosis of the incus can be distinguished. Fig. 7.23 Right ear. Perforation of the inferior quadrants of the tympanic membrane. All the tympanic membrane residue shows dense tympanosclerosis. Removal of these sclerotic plaques during myringoplasty assures an adequate vascularity to the graft and thus a high success rate for the operation. Fig. 7.24 Right ear. Similar case. The promontory and the round window are visible. A tympanosclerotic plaque that engulfs the ossicular chain is seen at the level of the posterosuperior border of the perforation. Fig. 7.25 Left ear. Subtotal perforation. The annulus as well as a fibrous rim is visualized along the inferior border of the perforation. The handle of the malleus is medialized. The tubal orifice, the hypotympanic air cells covered with mucosa, Jacobson’s nerve on the promontory, and the long process of the incus are visible. The residue of the tympanic membrane is thickened. In cases in which only a small anterior residue of the tympanic membrane is found, an overlay technique in which the graft is put over the annulus is used, thus preventing detachment of the anterior part of the graft leading to reperforation. Fig. 7.26 Left ear. Total perforation of the tympanic membrane through which evolving tympanosclerotic plaques are visible. The long process of the incus is partially eroded. The handle of the malleus is medialized and adherent to the promontory. The tubal orifice and the hypotympanic air cells are also noted.
7.2 Posterior Perforations
7.3 Anterior Perforations
7.4 Inferior Perforations
7.5 Subtotal and Total Perforations
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