7 Canal Wall Down Tympanoplasty



10.1055/b-0039-169411

7 Canal Wall Down Tympanoplasty



Indications




  • Cholesteatoma in cases of




    • Contracted mastoid



    • Large epitympanic erosions



    • Recurrence after the closed tympanoplasty



    • Bilateral cholesteatoma



    • Cleft palate and Down’s syndrome



    • Only hearing ear



    • Large labyrinthine fistula



    • Severe sensorineural hearing loss


When marked attic erosion is present in cholesteatoma, especially in adults, we perform a canal wall down (CWD; open) technique to avoid cholesteatoma recurrence that can occur due to absorption of the material used for reconstruction of the attic defect. In cases with sclerotic mastoids, or when middle ear atelectasis is present, a CWD tympanoplasty is also performed. The number of CWD techniques performed in our center is gradually increasing. As described, we now use canal wall up (CWU; closed) technique only in limited cases (< 10%) due to its higher percentage of recurrence and residual cholesteatoma. Today, we mainly apply CWD techniques in cholesteatoma surgery. According to our experience, a well-performed CWD cavity has more chance to prevent second operation with minimal declination of hearing and quality of life.


In CWD tympanoplasty, execution of correct technique is the key for successful surgery. In this technique, since posterior wall of the external auditory canal is removed, the mastoid and the external auditory canal became common communicating cavity exposed to outside after surgery. To avoid postoperative complications, it is very important to create an ideal cavity in the first surgery by following correct procedures such as sufficient saucerization of the cavity and appropriate meatoplasty. Saucerization of the entire cavity and removal of any overhang edges not only increase the working space but also allow soft tissue to fill in the bony defect. That makes the cavity smaller without using any material for obliteration. We always perform meatoplasty in CWD techniques, since this technique allows reduction of raw surface and further makes the cavity relatively small and shallow by enlarging its opening. An adequate meatoplasty is an essential prerequisite to obtain constant success in CWD tympanoplasties. If all procedures are properly performed, the cavity appears small, shallow, rounded in shape, dry, and well epithelized.


On the other hand, a badly performed cavity may appear wet, irregular, and difficult-to-reach periphery. The cavity may be lined with granulation tissue covered by accumulated debris. We have found that technical mistakes commonly seen in the failed cavity are a very narrow meatus and insufficient bone removal such as a high facial ridge, an overhanging edge, and a prominent mastoid tip. Each of these factors impedes self-cleansing of cerumen and debris from the cavity, resulting in inflammatory reaction. In addition, possibility of residual and recurrent cholesteatoma is higher in such cavity.


In this chapter, we describe three techniques used in our center.




  • If the ossicular chain is severely insulted or the middle ear is involved, we use a CWD tympanoplasty that consists of eradication of the disease from the middle ear with CWD and ossicular chain reconstruction.



  • For early epitympanic cholesteatoma in which continuation of articulations between the ossicles is preserved, modified Bondy technique yields best result in a single stage according to postoperative hearing, residual and recurrence rate.



  • For elderly patients with nonserviceable hearing and for cholesteatoma in difficult-to-reach area such as deep tympanic sinus, a safe, dry, self-cleaning ear may be the final goal. In such cases, we sacrifice middle ear function by applying radical mastoidectomy that consists of plugging of the eustachian tube and elimination of air space medial to the tympanic membrane.


The patients who have recurrent cholesteatoma tend to have either poor physiologic function of eustachian tube or the most difficult-to-manage disease status. Revision surgery by preserving the canal wall is likely to expense the patient and family to face new surgery. Therefore, once recurrence occurred, we do not hesitate to convert the procedure to CWD technique by removing the posterior canal wall.



7.1 Canal Wall Down Tympanoplasty



7.1.1 Surgical Steps



Removal of the Posterior Canal Wall



  1. If CWD tympanoplasty has been planned preoperatively, the mastoidectomy can be performed in two ways. After completing mastoidectomy, the shape of the cavity obtained with two procedures should be the same.




    1. Transcortical


      Simple mastoidectomy and atticoantrostomy is completed from the posterior cavity just like closed technique. Thinned posterior wall may be removed with either burrs or a rongeur.



    2. Transmeatal


      Identify first the middle fossa plate. Enlarge the external auditory canal by following the middle fossa plate posteriorly toward the sinodural angle. The sigmoid sinus is identified at this point. The mastoid cavity is gradually opened from anterior to posterior.



  2. The cavity must always be saucerized and gradually deepened. Bony overhangs should be removed from the edges. A round-shaped cavity should be obtained at the end of the drilling.



  3. All the bone covering the middle fossa dura and the sigmoid sinus is thinned with large burrs moved parallel to these structures (▶Fig. 7.1). If bone is appropriately removed, middle fossa dura is clearly identified through the thinned bone by its pinkish color, and the sigmoid sinus is clearly identified by its bluish color (▶Fig. 7.2).



  4. Removal and exteriorization of all air cells posterior to the mastoid segment of the facial nerve and the sigmoid sinus is carried out.



  5. Sufficient bone removal from the sinodural angle is also a part of the procedure.



  6. The facial ridge is lowered evenly by drilling the posterior canal wall with a large cutting burr, with continuous suction irrigation. The burr should be moved always parallel to the course of the facial nerve. Diamond burrs are reserved for final drilling to thin the bony coverage of the nerve. In this procedure, the nerve is skeletonized laterally until the nerve becomes visible through a thin bony shell, but never exposed (▶Fig. 7.3).



  7. In the area of the facial bridge, a burr is moved parallel to the middle fossa plate so as not to hit it accidentally with the burr.



  8. In poorly pneumatized mastoid frequently seen in chronic otitis media, level of the ideally drilled facial ridge is almost in the same plane of the drilled mastoid cavity.



  9. If there is prominent protrusion in anterior or inferior wall, canalplasty should be carried out. The anterior attachment of the facial bridge is lowered sufficiently (▶Fig. 7.4). The anterior meatal skin is cut laterally and detached from the bone toward the annulus. The medially folded meatal skin flap is protected with an aluminum sheet (▶Fig. 7.5). The anterior and/or the inferior meatal walls are drilled to obtain round-shaped cavity. Care should be taken not to expose the temporomandibular joint beneath the anterior wall.



  10. The final shape of the cavity is a reversed pyramid with rounded external edges with no bony overhang in the cavity. Drilling to correct the shape of the cavity should be carried out to such extent.

Fig. 7.1 Bone covering the middle fossa dura and sigmoid sinus it thinned using large burrs which should move parallel to those structures.
Fig. 7.2 When enough bone is removed, the middle fossa dura will look pink through the bone and the sigmoid sinus blue.
Fig. 7.3 The facial ridge is drilled using a large cutting burr moving parallel to the nerve.
Fig. 7.4 If protruding, the anterior attachment of the facial bridge (1) and the anterior canal wall (2) should be drilled.
Fig. 7.5 The meatal skin flap and the tympanic membrane should be protected by aluminum when drilling the canal wall.


Management of the Tympanic Cavity



  1. Management of the tympanic cavity should be conducted as soon as possible after sufficient and safe access is established. In this way, hemostasis in the tympanic cavity is achieved before starting reconstruction. Bloodless field is very important for correct arrangement of the reconstruction materials. For that sake, some bone work away from the tympanic cavity may be carried out after managing the tympanic cavity.



  2. The fibrous annulus is detached from the tympanic sulcus posteriorly, and the tympanomeatal flap is elevated to explore the middle ear.



  3. The facial bridge, and then the anterior and posterior buttresses are removed, preferably using a curette (▶Fig. 7.6). Removal of the anterior buttress produces a continuous plane between the middle fossa plate and the anterior canal wall (▶Fig. 7.4).



  4. A bony overhang of the anterior epitympanic recess should be removed to ensure complete control of this area after the surgery. Air cells in this area are removed as much as possible.



  5. Pathology should be carefully dissected from the middle ear not to damage the underlying fragile structures such as the facial nerve, the oval and round windows, the stapes, and the labyrinth. If view of such structures is obstructed by the facial ridge, it may be further lowered (▶Fig. 7.7, ▶Fig. 7.8). The skin of the external auditory canal, the annulus, tympanic membrane, the incus, and/or the malleus may be removed depending on the status of the lesion (▶Fig. 7.9).



  6. When ossiculoplasty is planned, the handle of the malleus and the tendon of the tensor tympani muscle are preserved if possible. Those structures give adequate support to the columella and provide better hearing result.



  7. If the body of the incus is involved but the incudostapedial joint remains intact, cutting the incus in the long process is preferred (▶Fig. 7.10). The remaining portion of the incus may serve as a columella if the facial ridge is lowered sufficiently (▶Fig. 7.11).



  8. To stop bleeding for reconstruction procedures, the tympanic cavity is momentarily packed with small cottonoids after completing management of it.

Fig. 7.6 Landmarks for the facial nerve are shown. 1, short process of the incus; 2, lateral semicircular canal; 3, digastric ridge.
Fig. 7.7 If obstructing the view, the facial ridge (green area) should be lowered.
Fig. 7.8 View of the extent of lowering the facial ridge. RW, round window.
Fig. 7.9 Removal of middle ear structures depends on the pathology in this case. The long process of the incus is eroded and thus removed.


Management of Pneumatized Temporal Bones



  1. In highly pneumatized mastoid, any invaginated areas and air cells, especially perilabyrinthine and retrofacial cells (▶Fig. 7.12) and cells in attic, should be drilled to complete removal of matrix and to avoid postoperative accumulation of skin debris.



  2. The retrofacial cells are exenterated completely. During this maneuver, care should be taken not to damage the mastoid segment of the facial nerve. Sometimes, in a highly pneumatized mastoid, the retrofacial cells reach the area of the jugular bulb, medial to the facial nerve.



  3. In some cases, the retrofacial cells go far medially to the facial nerve, making complete exteriorization impossible. That area must be obliterated with autologous conchal cartilage.



  4. A prominent, well-pneumatized mastoid tip should be removed to reduce volume of the mastoid cavity (▶Fig. 7.13). Drilling starts from the level of the stylomastoid foramen, and continues posteriorly in a rotatory fashion parallel to the digastric ridge until the tip is undermined. It is important to create a fracture line lateral to the stylomastoid foramen to avoid any traction of the facial nerve in the following process. The remaining bony shell is mobilized and pulled out in a rotatory fashion with a bone rongeur, and detached from the muscle using electrocautery. This amputation of the mastoid tip not only reduces the cavity volume, but also prevents “sink trap effect” that may cause postoperative accumulation of skin debris.



  5. In well-pneumatized bone, large retrosigmoid air cells should also be removed if they are present (▶Fig. 7.14).



  6. Conchal cartilage harvested in meatoplasty, bone paté mixed with blood, and subcutaneous connective tissue are the materials for the obliteration. If the head of the malleus and the body of the incus are not present or removed, the attic may be obliterated with a piece of cartilage and bone paté.



  7. Sometimes, a retroauricular soft tissue flap based anteroinferiorly is used to obliterate the area of the mastoid tip (see ▶Fig. 7.53).

Fig. 7.10 When the body of the incus is involved but the incudostapedial joint is intact, we cut the incus at the long process.
Fig. 7.11 The remnant of the incus may act as a columella to restore hearing.
Fig. 7.12 Perilabyrinthine and retrofacial air cells are shaded in yellow.
Fig. 7.13 When prominent and well pneumatized, the mastoid tip should be removed.
Fig. 7.14 Highly pneumatized mastoid with anteriorly located sigmoid sinus. To obtain a good cavity, removal of the air cells posterior to the sigmoid sinus (arrow) is required in this case. MF, middle fossa; SS, sigmoid sinus.
Fig. 7.15 The fascia is cut longitudinally at the edge. One tongue is placed over the attic and the other inferior to the tendon of the malleus muscle in the middle ear cavity.


Reconstruction



  1. Before reconstructing the tympanic membrane, bleeding should be completely stopped. If tubal dysfunction is suspected, a Silastic sheeting designed to cover the medial wall of the tympanic cavity including the tubal orifice is placed. The eustachian tube and the tympanic cavity are packed with Gelfoam.



  2. The temporalis fascia is grafted underlay whenever it is possible. The overlay technique is used when the anterior annulus is not present. The graft must have abundant extension posteriorly to cover attic and obliterated cells, especially if an ossiculoplasty is performed in the same stage. Another piece of graft may be placed to cover exposed bone. Epithelization is facilitated if the exposed bone is covered with the fascia.



  3. If the tendon of the tensor tympani with the manubrium is preserved, a longitudinal cut is made in the edge of the temporalis fascia. One tongue is placed on the attic and goes into the protympanum, superiorly to the tendon. The other tongue is inserted inferiorly to the tendon, and placed in the tympanic cavity (▶Fig. 7.15).



  4. If the stapes superstructure is present and the facial ridge is sufficiently lowered, the fascia usually touches to the head of the stapes, and second-stage ossiculoplasty may not be required. A thin piece of cartilage placed over the stapes may be helpful. If the incudostapedial joint is left intact, additional height of the long process of the incus over the superstructure may give sufficient contact with the tympanic membrane. If the height is insufficient, a piece of cartilage may be interposed (▶Fig. 7.16).



  5. A meatoplasty should be performed in all the cases. (see Meatoplasty in this chapter).

Fig. 7.16 When the height of the left part of the incus is insufficient, it could be augmented using a cartilage graft.

An experienced surgeon can remove cholesteatoma with CWU technique. However, by removing the posterior wall, wide and safe access to the middle ear can be established without having a big cavity (see ▶Fig. 7.17 a, b)

Fig. 7.17 (a) A case of contracted mastoid. (b) Dissection of cholesteatoma through contracted mastoid.


Meatoplasty

After open techniques, the meatus and the mastoid become a common cavity that is much larger than the original meatus. That makes deep, difficult-to-reach area where self-cleansing or even cleaning in the outpatient clinic is difficult from the original meatus. Accumulation of epithelial debris may cause undesirable repetitive inflammation and even cholesteatoma. In our series of revision, open tympanoplasty formerly operated in elsewhere, meatal stenosis is found in about 60% of failed cavity. To avoid cavity problem, we always perform meatoplasty in open techniques. In this procedure, the meatal skin is folded medially and the opening is enlarged to obtain relatively small, shallow, and easy-to-access cavity. The procedure also covers the cavity with skin, which enhances postoperative healing. After complete epithelization, no special restriction is required including water sports and travel. We believe an adequate meatoplasty that suits the dimension of the cavity is an essential prerequisite to obtain successful result steadily in open tympanoplasties.




  1. Meatoplasty is performed after completing mastoidectomy in every case in which open technique is conducted to adjust the size of the meatus to the cavity.



  2. If conchal cartilage is required for reconstruction, the cavity is packed with cottonoids to achieve complete hemostasis and to prevent blood filling the cavity before starting meatoplasty. If reconstruction is completed, the cavity, especially in the area of tympanic membrane, should be partially packed with the Gelfoam to secure reconstructed structures. Small cottonoids are placed over it. After removing self-retaining retractors, folded gauze is placed on the retroauricular wound to prevent blood from falling down into the cavity. The auricle is positioned in its original place.



  3. Using a nasal speculum, the concha is stabilized. The conchal incision is made from the surface of the auricle (▶Fig. 7.18). The skin, conchal cartilage, and connective tissue are incised together from the middle of posterior meatal wall toward the anthelix, in parallel to the crus of helix (▶Fig. 7.19). Length of the incision required depends on the size of the cavity (larger cavity requires longer incision). At least, the digit finger should pass easily after removing conchal cartilage. The incision, however, never reaches the anthelix.



  4. The skin is held with forceps and dissected from the underlying cartilage using sharp tympanoplasty scissors (▶Fig. 7.20). Then, soft tissue beneath the cartilage is also detached from it (▶Fig. 7.21). After exposing sufficient amount of cartilage, it is removed, triangular in shape, from each side of the edges (▶Fig. 7.22). The amount of cartilage removed varies depending on the size and contour of the cavity. However, it is important to preserve cartilage in the crus of the helix. Otherwise, cosmetic deformity may follow.



  5. If the removal is insufficient, the cartilage can be removed from the retroauricular wound. The auricle is folded anteriorly and held by a scrub nurse. The cartilage is further trimmed by removing a crescent-shaped piece from the edge. Sufficient removal of the cartilage facilitates folding of the skin medially, which serves not only for reducing raw surface in the cavity but also for preventing postoperative perichondritis caused by inappropriate exposure of the resected edge in the wound. To further facilitate medial folding, the skin flaps may be thinned by trimming subcutaneous soft tissue.



  6. From the retroauricular wound, the meatal skin flaps are folded posteriorly (▶Fig. 7.23), and ideal position for the cavity is estimated. These flaps are finally sutured superiorly and inferiorly to the musculoperiosteal layer with 3/0 Vicryl (▶Fig. 7.24). Make sure that the raw surface in the edge of the cartilage is fully covered by conchal skin or soft tissue.



  7. After suturing the meatal skin flaps, center of the entire conchal cartilage may be pulled posterosuperiorly and posteroinferiorly. This may cause anterior rotation of the entire auricle, making the auricle prominent postoperatively. Useful technique to avoid this cosmetic problem is to put a couple of sutures deeply in soft tissue more lateral to the meatus, and retract the auricle posteriorly.

Fig. 7.18 A dotted line demonstrates the site of incision.
Fig. 7.19 The skin, conchal cartilage, and connective tissue are incised parallel to the crus of the helix.
Fig. 7.20 The skin is held with forceps and dissected from the underlying cartilage using sharp tympanoplasty scissors.
Fig. 7.21 Dissecting conchal cartilage from the underlying connective tissues.
Fig. 7.22 Triangular areas of cartilage are removed.
Fig. 7.23 The ideal position for the flaps is estimated.
Fig. 7.24 The shape of the meatoplasty after suturing skin flaps.


Case 7.1 (Right Ear): Procedures of Meatoplasty


See ▶Fig. 7.25, ▶Fig. 7.26, ▶Fig. 7.27, ▶Fig. 7.28, ▶Fig. 7.29, ▶Fig. 7.30, ▶Fig. 7.31, ▶Fig. 7.32.

Fig. 7.25 To obtain a dry self-cleaning canal wall down cavity constantly, meatoplasty is of tremendous importance, and it should be performed in all cases. After finishing all bone works, a piece of folded gauze is put over the cavity to prevent blood running into the cavity, and the auricle is placed back. The concha is stabilized with a nasal speculum. The dotted line indicates incision line in the concha.
Fig. 7.26 A cut is made with a Beaver’s blade including the underlying conchal cartilage. The cut runs almost parallel to the crus of the helix, toward the anthelix.
Fig. 7.27 The conchal cartilage is dissected from subcutaneous tissue with scissors to expose sufficient area. Since the cartilage is fragile, it is wise to hold the skin, not the cartilage during this procedure. The cartilage to be removed is indicated by the dotted line.
Fig. 7.28 Dissection of the cartilage from the skin of the concha is on the way.
Fig. 7.29 The conchal cartilage is resected from the inferior edge, and taken out. The cartilage in the superior edge will be removed in the same manner.
Fig. 7.30 The auricle is reflected anteriorly, and the concha is viewed from the retroauricular wound. If not enough cartilage has been removed from lateral, the removal can be augmented from this side. In this case, the conchal cartilage is sufficiently removed to open the meatus widely.
Fig. 7.31 To open the meatus widely, two flaps in the concha should be sutured (arrows) to the subcutaneous tissue at the end of the surgery. Suture of the superior flap is in progress. F, soft tissue flap.
Fig. 7.32 When adequately sutured, the meatus keeps its shape by itself. After suturing of the retroauricular wound in two layers, the enlarged meatus is packed with Gelfoam to ensure intimate attachment to subcutaneous tissue and underlying bone.


Packing and Closure


The cavity is packed with Gelfoam soaked in physiologic saline. Generally, no antibiotic ointment is used. The retroauricular incision is closed by suturing the skin in two layers, or in one layer with Steri Strip. Usually, after radical mastoidectomy and modified Bondy technique, second-stage operation is not necessary. Epithelization of the cavity is completed within 8 weeks in most of the cases.



7.1.2 One-Stage Surgery in Canal Wall Down Tympanoplasty

As mentioned, staged surgery where cholesteatoma is removed in the first stage and removal of residual disease, if any, and reconstruction of ossicular chain are performed in the second stage usually gives better hearing result. Status of mucosa around the oval window and stability of the previously reconstructed tympanic membrane mainly give such difference. The second-stage surgery can be carried out easily under an ear speculum under local anesthesia as far as the first-stage canal wall down procedure is conducted correctly giving sufficient access to the tympanic cavity. Main drawbacks of such strategy are necessity of the other surgery and postoperative hearing disturbance. In limited cases, one-stage surgery is preferred especially in better hearing ear with healthy mucosa in the tympanic cavity especially around the stapes. In marginal cases to which modified Bondy technique might be applied, actual surgical procedure is decided in the operating field. If there is any uncertainty of complete removal from the area medially to the ossicular chain, the surgeon should remove some part of ossicular chain. Since mucosa in the tympanic cavity usually keeps good condition, such cases are good candidates for one-stage surgery.



Case 7.2 (Right Ear)


See ▶Fig. 7.33, ▶Fig. 7.34, ▶Fig. 7.35, ▶Fig. 7.36, ▶Fig. 7.37, ▶Fig. 7.38, ▶Fig. 7.39, ▶Fig. 7.40, ▶Fig. 7.41, ▶Fig. 7.42, ▶Fig. 7.43, ▶Fig. 7.44, ▶Fig. 7.45, ▶Fig. 7.46, ▶Fig. 7.47, ▶Fig. 7.48, ▶Fig. 7.49, ▶Fig. 7.50, ▶Fig. 7.51, ▶Fig. 7.52, ▶Fig. 7.53, ▶Fig. 7.54, ▶Fig. 7.55, ▶Fig. 7.56, ▶Fig. 7.57, ▶Fig. 7.58.

Fig. 7.33 The surface of the mastoid is exposed through a retroauricular incision. The bluish area just posterior to the external auditory canal corresponds to the sigmoid sinus, and the pinkish area superior to it corresponds to the middle fossa dura. Very narrow area is left between two structures. The tympanomeatal flap is protected with aluminum sheeting. MFP, middle fossa plate; SS, sigmoid sinus.
Fig. 7.34 The posterior meatal skin is detached medially to reach the area of the tympanic membrane. Note that the sigmoid sinus and the middle fossa dura touch to the posterior canal wall. The orifice of the cholesteatoma eroding the attic is seen (arrow).
Fig. 7.35 After detaching the anterior meatal skin, canaloplasty is carried out. An aluminum sheeting is used to protect the meatal skin and the ossicular chain. Note that there is still some bone remaining in the anterior wall.
Fig. 7.36 Drilling of the anterior wall is advanced medially to visualize the fibrous annulus (arrow).
Fig. 7.37 The fibrous annulus is detached from the bony annulus to ensure absence of cholesteatoma.
Fig. 7.38 The orifice of the cholesteatoma is shown by pushing the matrix inferiorly. Note that the attic is not accessible without removing the posterior wall.
Fig. 7.39 With a cutting burr, the orifice of cholesteatoma is enlarged.
Fig. 7.40 The matrix is opened. The amount of the bone to be drilled is estimated, and location of the ossicular chain is verified with the dissector.
Fig. 7.41 The atticotomy is enlarged along the sinodural angle. To avoid touching to the ossicular chain, the drill should be moved from medial to lateral (arrow).
Fig. 7.42 The antrum is opened. Thin matrix covering the medial wall is seen. LSC, lateral semicircular canal; P, promontory.
Fig. 7.43 The air cells should be removed as much as possible to ensure removal of the cholesteatoma matrix. Note the narrow approach limited by the two major structures, the sigmoid sinus and the middle fossa dura. Great care should be taken not to damage the sigmoid sinus and the dura medially to the protrusions. The attic is packed with cottonoid for hemostasis. MFP, middle fossa plate; SS, sigmoid sinus.
Fig. 7.44 The matrix is removed from the antrum.
Fig. 7.45 The facial ridge is lowered with a diamond burr.
Fig. 7.46 The posterior buttress has been removed, to visualize the incus. Because of the extension of the cholesteatoma reaching anteriorly to the head of the malleus, the incudostapedial joint is disarticulated.
Fig. 7.47 Removal of the incus is completed. No cholesteatoma is seen medially to the incus. The cholesteatoma is seen invaginating the supratubal recess (arrow). FN, facial nerve; M, head of malleus; S, stapes.
Fig. 7.48 The head of the malleus is cut with the malleus nipper to open the supratubal recess.
Fig. 7.49 The bone covering the cholesteatoma is removed.
Fig. 7.50 The tendon of the tensor tympani is cut and the anterosuperior part of the fibrous annulus is detached. The tympanic membrane is reflected inferiorly to enhance access to the supratubal recess. The structures around the cochleariform process are shown. In such tight anatomical condition, maximal exposure of structures that gives appropriate orientation is of tremendous importance. CP, cochleariform process; FN, area of facial nerve; LSC, lateral semicircular canal; S, stapes; TT, tensor tympani.
Fig. 7.51 The anterior buttress should be removed to make the cavity rounded.
Fig. 7.52 Eradication of cholesteatoma from the middle ear is completed. CP, cochleariform process; FN, facial nerve; LSC, lateral semicircular canal; S, stapes; RW, round window niche.
Fig. 7.53 Meatoplasty is carried out, and conchal cartilage is utilized to obliterate the dips located medially to the sigmoid sinus and the middle fossa plate.
Fig. 7.54 A large piece of temporalis fascia is used to cover the medial wall of the cavity.
Fig. 7.55 The tympanomeatal flap is replaced over the fascia. The handle of the malleus attached to the tympanic membrane is clearly seen (arrow).
Fig. 7.56 The fascia is reflected anteriorly to visualize the stapes. FN, facial nerve; RW, round window; S, stapes.
Fig. 7.57 A thick piece of cartilage is placed over the head of the stapes. The tympanic cavity is packed with Gelfoam to support the cartilage and the reconstructed tympanic membrane. After replacing the fascia and the tympanomeatal flap, the cavity is packed with Gelfoam.
Fig. 7.58 The fascia is replaced, and the cavity is packed with Gelfoam.


Case 7.3 (Left Ear)


See ▶Fig. 7.59, ▶Fig. 7.60, ▶Fig. 7.61, ▶Fig. 7.62, ▶Fig. 7.63, ▶Fig. 7.64, ▶Fig. 7.65, ▶Fig. 7.66, ▶Fig. 7.67, ▶Fig. 7.68, ▶Fig. 7.69, ▶Fig. 7.70, ▶Fig. 7.71.

Fig. 7.59 The meatus is entered via retroauricular incision. A small erosion is identified in the pars flaccida (arrow).
Fig. 7.60 Before starting mastoidectomy, the tympanic cavity is opened to verify absence of cholesteatoma and continuity of the ossicular chain. The chorda tympani nerve (white arrow) and the incudostapedial joint (yellow arrow) are identified.
Fig. 7.61 Mastoidectomy is started with canal wall up procedure maintaining the posterior wall of the external auditory canal. The middle fossa plate and the sigmoid sinus are identified superiorly and posteriorly, respectively. Since the temporal bone is compact, no aircell is encountered before reaching the antrum. MFP, middle fossa plate; SS, sigmoid sinus.
Fig. 7.62 Since the antrum in the compact bone is completely filled with cholesteatoma, application of canal wall down procedure is decided. The posterior wall is removed with a large cutting burr.
Fig. 7.63 The drilling is advanced from lateral to medial taking care not to make any acute angle in the cavity. MFP, middle fossa plate; SS, sigmoid sinus.
Fig. 7.64 The sinodural angle should be opened widely. The burr should be moved from medial to lateral in this location as demonstrated by the arrow.
Fig. 7.65 Access to the attic is enlarged with a small cutting burr. Drilling around the attic should be carried out with maximal care, not to touch the ossicular chain.
Fig. 7.66 The attic is opened fully, and the majority of cholesteatoma around the chain has already been removed. The incus is heavily eroded. Cottonoid is used to remove matrix behind the chain.
Fig. 7.67 Cholesteatoma located anteriorly to the head of the malleus is started to be dissected.
Fig. 7.68 Anteriorly to the heavily eroded head, a deep invagination reaching inaccessible area (arrow) is identified. I, incus; M, malleus.
Fig. 7.69 After disarticulating the incudostapedial joint, the incus is removed. The head of the malleus is cut with scissors.
Fig. 7.70 The cholesteatoma is eradicated from the middle ear. The tendon of the tensor tympani muscle is cut to allow anterior reflection of the tympanic membrane. The procedure enlarges access to cholesteatoma invaginating the eustachian tube. ET, eustachian tube; S, stapes.
Fig. 7.71 A piece of cartilage is placed over the stapes. The cartilage serves as a columella and reinforcement material of the tympanic membrane. The cavity is covered with a large piece of temporalis fascia, and the tympanomeatal flap is replaced over it.


Case 7.4 (Right Ear)


See ▶Fig. 7.72, ▶Fig. 7.73, ▶Fig. 7.74, ▶Fig. 7.75, ▶Fig. 7.76, ▶Fig. 7.77, ▶Fig. 7.78, ▶Fig. 7.79, ▶Fig. 7.80, ▶Fig. 7.81.

Fig. 7.72 A case of cholesteatoma with prominent sigmoid sinus is shown. (a) The axial CT demonstrated that the protruded sigmoid sins narrow access to the antrum. (b) The more caudal slice demonstrates a large jugular bulb in the tympanic cavity. A, antrum; JB, jugular bulb; LSC, lateral semicircular canal; SS, sigmoid sinus.
Fig. 7.73 The surface of the mastoid is exposed for mastoidectomy. A bluish area (arrow) occupying posterior half corresponds to the prominent sigmoid sinus.
Fig. 7.74 An inflamed entrance of cholesteatoma is located in pars flaccida of the tympanic membrane (arrow).
Fig. 7.75 Canal wall down mastoidectomy is carried out taking care not to expose the protruded sigmoid sinus. To maximize access to the middle ear, the cavity should be saucerized from the beginning by skeletonizing both the middle fossa and the sigmoid sinus without creating sharp bony edges. SS, sigmoid sinus.
Fig. 7.76 The antrum filled with cholesteatoma is opened. Simultaneously, the posterior wall is lowered, and the bony meatus is calibrated. The tympanomeatal flap should be protected by aluminum sheeting. Some meatal skin or cottonoids should be present between the aluminum sheeting and the lateral process of the malleus to prevent sensorineural hearing loss. Ch, cholesteatoma.
Fig. 7.77 Access to the antrum is enlarged by thinning the bony plate covering the middle fossa and the sigmoid sinus. The perilabyrinthine cells where the matrix is invaginating need to be drilled. MFP, middle fossa plate; SS, sigmoid sinus.
Fig. 7.78 The attic filled with cholesteatoma is shown. The body of the incus is completely eroded.
Fig. 7.79 Exploration of the tympanic cavity revealed limited extension of cholesteatoma in the mesotympanum. A large jugular bulb occupying posteroinferior part of the tympanic cavity is shown (arrow). Note that the top of this jugular bulb is not covered by a bone. CT, chorda tympani.
Fig. 7.80 The incus and the head of the malleus are removed and cholesteatoma is eradicated from the middle. The tympanic segment of the facial nerve is exposed just posteriorly to the cochleariform process (yellow arrow). Very large jugular bulb almost touching to the stapes (white arrow) is seen. FN, facial nerve; JB, jugular bulb; LSC, lateral semicircular canal.
Fig. 7.81 The tympanic cavity is packed with Gelfoam, and a large piece of cartilage is placed over the stapes. A fascia is grafted underlay to reconstruct the tympanic membrane and to cover the medial wall of the mastoid.


7.1.3 Staged Surgery in Canal Wall Down Tympanoplasty


In many cases of cholesteatoma, the tympanic cavity is involved and the tympanic membrane is retracted. The tympanic cavity may get scar or granulation tissue, or the tympanic membrane may be adherent to the medial wall. Closure of perforations may be required. In such situation, unpredictable factors such as rescarring of the tympanic cavity, adhesion of the reconstructed tympanic membrane, and displacement of the columella due to postoperative migration of the tympanic membrane may interfere postoperative sound transmission. To obtain more stable result, the surgery is often staged, and the ossicular chain is reconstructed in the second stage. In addition, residual disease, if any, can be removed and retraction pocket may be corrected in the second stage, to enhance curability of the entire surgery.



Case 7.5 (Left Ear)


See ▶Fig. 7.82, ▶Fig. 7.83, ▶Fig. 7.84, ▶Fig. 7.85, ▶Fig. 7.86, ▶Fig. 7.87, ▶Fig. 7.88, ▶Fig. 7.89, ▶Fig. 7.90, ▶Fig. 7.91, ▶Fig. 7.92, ▶Fig. 7.93, ▶Fig. 7.94, ▶Fig. 7.95.

Fig. 7.82 A case of cholesteatoma in contracted mastoid. The CT demonstrates large erosion in the attic. The head of the malleus can be seen in the attic, but the incus and the superstructure of the stapes are absent. C, cochlea; Ch, cholesteatoma; IAC, internal auditory canal; JB, jugular bulb; M, malleus.
Fig. 7.83 The middle fossa plate and the sigmoid sinus are identified superiorly and posteriorly, respectively. The tympanomeatal flap is protected with an aluminum sheeting. Note that the cavity is well saucerized. The anterior meatal wall is also calibrated. MFP, middle fossa plate; SS, sigmoid sinus.
Fig. 7.84 Drilling is advanced medially to reach the small antrum filled with cholesteatoma. Note that development of aircell system in the mastoid is very poor, and the small antrum is surrounded by compact bone.
Fig. 7.85 All sharp bony edges in the cavity should be removed to make the cavity rounded. The tympanomeatal flap is protected with a piece of aluminum sheet.
Fig. 7.86 To facilitate postoperative care and second-stage surgery, the anterior and the inferior meatal walls should also be calibrated.
Fig. 7.87 The calibration of the meatal wall should be carried out to such extent that the entire annulus (arrows) can be seen without moving microscope.
Fig. 7.88 The facial ridge is further lowered with a small cutting burr, and saucerization of the cavity is completed.
Fig. 7.89 The fibrous annulus is detached from inferior. Note that the anteriorly located very large jugular bulb forms the inferior wall of the tympanic cavity, and small part of it is exposed in the bony annulus (arrow). In such situation, inattentive dissection of the fibrous annulus may damage the bulb, and considerable bleeding may occur. Application of Surgicel over the small hole eventually stops such bleeding.
Fig. 7.90 Dissection of the fibrous annulus is advanced superiorly taking care not to leave cholesteatoma matrix covering the posterior wall of the tympanic cavity. The incus is completely eroded, and the superstructures of the stapes are completely eroded. The chorda tympani nerve (white arrow) and the footplate of the stapes (yellow arrow) can be seen.
Fig. 7.91 Dissection of the fibrous annulus is advanced superiorly taking care not to leave cholesteatoma matrix covering the posterior wall of the tympanic cavity. The incus is completely eroded, and the superstructures of the stapes are completely eroded. The chorda tympani nerve is sacrificed. The footplate of the stapes (arrow) can be seen inferiorly to the exposed facial nerve. FN, facial nerve; JB, jugular bulb; M, head of malleus.
Fig. 7.92 In higher magnification, the Jacobson’s nerve running over the promontory is seen (white arrow). The cochleariform process (yellow arrow) forms the anterosuperior rim of the oval window niche (black arrow), and the facial nerve courses just superomedial to it. FN, facial nerve; FP, footplate.
Fig. 7.93 Closer view of structures in the posterior mesotympanum. FN, facial nerve; FP, footplate; JB, jugular bulb; M, head of malleus; P, promontory; RWN, round window niche.
Fig. 7.94 A small piece of Silastic sheeting is placed in the tympanic cavity.
Fig. 7.95 A large piece of temporalis fascia is used to reconstruct the tympanic membrane and to cover the medial wall of the cavity which is partially obliterated with pieces of conchal cartilage and bone paste. The tympanomeatal flap with malleus is replaced over the fascia, and the cavity is packed with pieces of Gelfoam.


Second Stage of This Case


See ▶Fig. 7.96, ▶Fig. 7.97, ▶Fig. 7.98, ▶Fig. 7.99, ▶Fig. 7.100, ▶Fig. 7.101, ▶Fig. 7.102, ▶Fig. 7.103.

Fig. 7.96 Second-stage surgery of the same case. The cavity is well epithelized. The malleus left in the first stage can be identified (arrow). Note that the tympanic membrane is easily accessible as a result of sufficient bone work in the inferior and anterior bony meatus in the first-stage surgery.
Fig. 7.97 A U-shaped incision is made from the anterior wall to the posterior wall to open the tympanic cavity from inferior. A small piece of cottonoid is used to dissect the meatal skin so as not to damage it and also to control hemorrhage.
Fig. 7.98 The tympanic cavity is opened from inferior to sufficiently expose the area of the footplate. Silastic sheeting placed in the first stage is seen.
Fig. 7.99 The tympanic cavity is opened from inferior to sufficiently expose the area of the footplate, and the Silastic sheeting is removed. The promontory (P) is located between the round window niche (black arrow) and the oval window covered with mucosal fold (blue arrow).
Fig. 7.100 The mucosal fold covering the footplate is removed. The remnant of the anterior crus is seen (arrow).
Fig. 7.101 The tympanic cavity is partially packed with pieces of Gelfoam. The area of the footplate is left unpacked for following ossiculoplasty.
Fig. 7.102 The incus is molded to fit the distance between the tympanic membrane and the footplate.
Fig. 7.103 The molded incus is in position. The columella is supported with pieces of Gelfoam to avoid adhesion to the promontory located inferiorly and to the facial nerve located superiorly. To ensure appropriate alignment of the columella over the footplate, the area posterior to the columella is left unpacked at this moment. The space should be packed later to avoid adhesion of the columella to the posterior wall. The cavity will be closed by replacing the tympanomeatal flap.


Case 7.6 (Right Ear)


See ▶Fig. 7.104, ▶Fig. 7.105, ▶Fig. 7.106, ▶Fig. 7.107, ▶Fig. 7.108, ▶Fig. 7.109, ▶Fig. 7.110, ▶Fig. 7.111, ▶Fig. 7.112, ▶Fig. 7.113, ▶Fig. 7.114, ▶Fig. 7.115, ▶Fig. 7.116, ▶Fig. 7.117, ▶Fig. 7.118, ▶Fig. 7.119.

Fig. 7.104 Canal wall down mastoidectomy is carried out. The posterior end of cholesteatoma reaching the antrum is beginning to be seen. The tympanomeatal flap is detached from the bony meatus and protected with aluminum sheeting for canaloplasty.
Fig. 7.105 The canaloplasty is completed, and the scutum is removed with a curette after thinning the bony bridge lateral to the chain. The cholesteatoma in the attic is visualized.
Fig. 7.106 Debulking and piecemeal removal of cholesteatoma is of importance to visualize structures around the matrix, and to make room for dissection.
Fig. 7.107 Continuity of the ossicular chain is not compromised by the cholesteatoma. The tympanic membrane remains intact. Modified Bondy technique to preserve continuity of the chain may be indicated in this situation. I, incus.
Fig. 7.108 The facial ridge is further lowered to the level of the tympanic membrane to obtain good rounded cavity. The tympanomeatal flap should be protected by aluminum sheeting during drilling.
Fig. 7.109 The fibrous annulus is detached to verify absence of cholesteatoma in the tympanic cavity. The long process of the incus is seen (arrow).
Fig. 7.110 The cholesteatoma is detached from the incus. The lateral face of the incus is considerably eroded, but continuity of the ossicular chain is retained.
Fig. 7.111 Bony overhangs are removed with a cutting burr to expose the cholesteatoma extending anteriorly. To avoid contact to the ossicular chain, the drill should be moved either from the area near the chain to elsewhere, or parallel to the chain.
Fig. 7.112 Removal of the bone covering the supratubal recess revealed invagination of cholesteatoma into the supratubal recess.
Fig. 7.113 Debulking of the cholesteatoma reveals considerable invagination of the matrix anteriorly to the malleus. Since access to this area is blocked by the ossicular chain, removal of the malleus and the incus is indicated.
Fig. 7.114 After disarticulating the incudostapedial joint, the incus is removed.
Fig. 7.115 The head of the malleus is removed, and the tendon of the malleus is cut to widely open the area of the supratubal recess.
Fig. 7.116 The cholesteatoma is eradicated from the middle ear. Note that the transection of the tendon followed by inferior reflection of the tympanic membrane sufficiently enlarged the approach to the supratubal recess. The facial nerve is exposed, and protruded to touch to the stapes. CP, cochleariform process; FN, facial nerve; P, promontory; SH, head of stapes; ST, tendon of stapes.
Fig. 7.117 After partially packing the tympanic cavity with Gelfoam, Silastic sheeting is placed to avoid postoperative adhesion of the tympanic membrane to the structures in the medial wall.
Fig. 7.118 A large piece of temporalis fascia is grafted underlay., and the meatal skin is replaced over the fascia. Packing of the cavity with Gelfoam follows.
Fig. 7.119 A postoperative otoscopy. Second-stage surgery is planned within 1 year.


Case 7.7 (Right Ear)


See ▶Fig. 7.120, ▶Fig. 7.121, ▶Fig. 7.122, ▶Fig. 7.123, ▶Fig. 7.124, ▶Fig. 7.125, ▶Fig. 7.126, ▶Fig. 7.127, ▶Fig. 7.128, ▶Fig. 7.129, ▶Fig. 7.130, ▶Fig. 7.131, ▶Fig. 7.132, ▶Fig. 7.133.

Fig. 7.120 Canal wall down mastoidectomy is carried out, and part of cholesteatoma in the mastoid is removed. No cholesteatoma is seen medially to ossicular chain. The cholesteatoma going down to the posterior part of the mesotympanum is indicated by the arrow.
Fig. 7.121 To improve access to the tympanic cavity and to prevent postoperative open cavity problems, canaloplasty with lowering of the facial ridge is conducted. The tympanomeatal flap should be protected with aluminum sheeting.
Fig. 7.122 The tympanomeatal flap is elevated and the tympanic cavity is opened. The cholesteatoma descends to the tympanic cavity through the space between the incus (white arrow) and the chorda tympani nerve (black arrow).
Fig. 7.123 The matrix is detached from the lateral aspect of the incus. Continuity of the ossicular chain is disturbed by an erosion of the long process of the incus (arrow).
Fig. 7.124 The incus is removed. The long process is eroded (arrow). I, incus; M, malleus.
Fig. 7.125 Removal of the incus, enlarged access to the cholesteatoma. Dissection of the matrix is from the facial nerve (arrow) is shown. M, malleus
Fig. 7.126 The facial ridge is sufficiently lowered to remove the matrix is dissected from the posterior wall of the tympanic cavity. The tendon of the stapedial muscle emerging from the pyramidal eminence is seen (arrow). The superstructure of the stapes, if present, can be found by following the tendon anteriorly. P, promontory; RWN, round window niche.
Fig. 7.127 Dissected matrix is cut away to improve view of the fragile area and to facilitate dissection without adding excessive force to the remnant of the ossicular chain.
Fig. 7.128 The matrix is dissected from the stapes (arrow). The tip of the long process of the incus remains on the superstructure.
Fig. 7.129 The remnant of the matrix (arrow) covering the superstructure should be removed with great care.
Fig. 7.130 The tip of the long process remained on the superstructure can be removed with scissors.
Fig. 7.131 The head of the malleus is cut. The bone covering the supratubal recess (arrow) should be removed.
Fig. 7.132 Eradication of cholesteatoma is verified by opening the tympanic cavity fully. The tendon of the tensor tympani muscle (arrow) emerging from the cochleariform process is cut, and the tympanic membrane is reflected inferiorly. FN, facial nerve; LSC, lateral semicircular canal; M, malleus (handle); S, stapes.
Fig. 7.133 The tympanic cavity is packed with Gelfoam, and Silastic sheeting is placed over it. The supratubal recess (black arrow) and a dip over the superior semicircular canal (yellow arrow) will be obliterated with pieces of cartilage. The cavity will be covered with a large piece of fascia, and the tympanomeatal flap is replaced over it.


Case 7.8 (Left Ear)


See ▶Fig. 7.134, ▶Fig. 7.135, ▶Fig. 7.136, ▶Fig. 7.137, ▶Fig. 7.138, ▶Fig. 7.139.

Fig. 7.134 Via retroauricular incision, the meatus is entered and calibration of the meatal wall is completed. A mastoidectomy is carried out to expose the posterior end of the cholesteatoma reaching the antrum. An aluminum sheeting to protect the tympanomeatal flap is seen in the bottom of the meatus.
Fig. 7.135 Canal wall down mastoidectomy is carried out, and cholesteatoma invaginating from the posterosuperior quadrant is exposed. The incus is completely lost, and the superstructure of the stapes is eroded.
Fig. 7.136 Evacuation of debris permits the surgeon to push the cholesteatoma matrix inferiorly to dissect the matrix from the anterior wall of the attic. The head of the malleus (arrow) impeding view of this area should be removed for further dissection.
Fig. 7.137 The cholesteatoma is removed from the supratubal recess after cutting the head of the malleus.
Fig. 7.138 The facial ridge is further lowered, and the matrix covering the area of the facial nerve is carefully dissected. The footplate of the stapes without the superstructure can be identified clearly (arrow). FN, facial nerve.
Fig. 7.139 The tympanomeatal flap is reflected anteriorly and cholesteatoma matrix adherent to the structures in the posterosuperior part of the tympanic cavity is cleaned. Note the skin still covering the promontory (arrow). The matrix is removed from the promontory, and Silastic sheeting is placed in the tympanic cavity. FN, facial nerve; RWN, radial window niche.


Second Stage of This Case


See ▶Fig. 7.140, ▶Fig. 7.141, ▶Fig. 7.142, ▶Fig. 7.143.

Fig. 7.140 The second-stage surgery is carried out through transmeatal approach under an ear speculum. The tympanic cavity is entered by elevating a U-shaped skin flap (see ▶Fig. 7.97). A small pearl is found on the anterior part of the footplate (arrow). The tympanic cavity is covered with healthy mucosa. FN, facial nerve; RWN, round window niche.
Fig. 7.141 The pearl is removed taking care not to damage the exposed facial nerve and not to add excessive force to the footplate. To ensure complete removal, the pearl is elevated with the underlying scar tissue.
Fig. 7.142 The area of the footplate (arrow) cleaned is seen. FN, facial nerve; RWN, round window niche.
Fig. 7.143 A homologous incus is used for columella connecting the footplate and the tympanic membrane. The columella is supported by small pieces of Gelfoam. A small piece of Gelfoam (arrow) is placed between the posterior wall and the columella to avoid adhesion.


Case 7.9 (Left Ear)


See ▶Fig. 7.144, ▶Fig. 7.145, ▶Fig. 7.146, ▶Fig. 7.147, ▶Fig. 7.148, ▶Fig. 7.149, ▶Fig. 7.150, ▶Fig. 7.151, ▶Fig. 7.152, ▶Fig. 7.153, ▶Fig. 7.154, ▶Fig. 7.155.

Fig. 7.144 A case of cholesteatoma with suspicion of labyrinthine fistula and exposure of the middle fossa dura. (a) The axial CT shows heavy erosion of the ossicular chain. (b) The coronal CT indicates possibilities of exposed middle fossa dura (white arrow), and a fistula in the lateral semicircular canal (black arrow).
Fig. 7.145 The meatus is opened via retroauricular incision. Bone erosion is seen in the pars flaccida of the tympanic membrane (yellow arrow). Bony protrusions in the anterior and inferior walls narrow the meatus. To calibrate the anterior wall, the anterior meatal skin is cut circumferentially (black arrow).
Fig. 7.146 The sigmoid sinus and the middle fossa dura are identified, and mastoidectomy is advanced medially to open the antrum. Cholesteatoma occupying the antrum is started to be seen. Note that no acute angle is left on edges, and the cavity is well saucerized. MFD, middle fossa dura; SS, sigmoid sinus.
Fig. 7.147 The posterior meatal wall is removed, and the cholesteatoma is opened to evacuate debris. No fistula is identified in the lateral semicircular canal. Meatoplasty is carried out to obtain round-shaped cavity.
Fig. 7.148 The tympanic cavity is opened from posterior, and the chorda tympani nerve is cut. The cholesteatoma erodes the superior aspect of the body of the incus, and goes medially to the ossicular chain. I, incus; RWN, round window niche.
Fig. 7.149 Dissection of the matrix from the mastoid is advanced anteriorly. A small area of the middle fossa dura is exposed in the tegmen of the mastoid (arrows). The matrix is dissected from the dura without difficulty.
Fig. 7.150 After disarticulating the incudostapedial joint, the incus is removed to dissect the matrix behind the ossicular chain. The tympanic segment of the facial nerve is seen. No fistula is found in the lateral semicircular canal. CP, cochleariform process; FN, facial nerve.
Fig. 7.151 To remove cholesteatoma occupying the supratubal recess (arrow), the head of the malleus is cut with scissors.
Fig. 7.152 The supratubal recess is opened, and the cholesteatoma is eradicated from the middle ear. CP, cochleariform process; FN, facial nerve; S, stapes.
Fig. 7.153 The tympanomeatal flap is replaced, and the final shape of the cavity is shown. The pars tensa of the tympanic membrane remains intact.
Fig. 7.154 To prevent adhesion of the tympanic membrane, Silastic sheeting is placed over the Gelfoam.
Fig. 7.155 Cartilage harvested in meatoplasty and bone paste is used to obliterate the area of the mastoid tip, medial walls of the attic and the antrum, and the exposed middle fossa dura. The temporalis fascia is grafted underlay, and the tympanomeatal flap is replaced over the fascia.

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May 12, 2020 | Posted by in OTOLARYNGOLOGY | Comments Off on 7 Canal Wall Down Tympanoplasty
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