OSSICULOPLASTY CHAPTER 4. James S. Batti, MD Charles D. Bluestone, MD

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1 CHAPTER 4 OSSICULOPLASTY James S. Batti, MD Charles D. Bluestone, MD This chapter reviews methods for reconstructing the ossicular chain from tympanic membrane to oval window, with emphasis on specific techniques for children with ossicular fixation or discontinuity. Information is also provided regarding outcomes and prognostic factors, with the caveat that most published data relate to adults. Lastly, the major reasons for failure are discussed and the current knowledge of ossiculoplasty in children is summarized. OSSICULAR RECONSTRUCTION Etiology of Ossicular Abnormalities Ossicular-related causes of conductive hearing loss can be congenital or acquired, and are mainly due to discontinuity or fixation: Ossicular discontinuity occurs in the following scenarios presented in order of decreasing frequency: eroded incudostapedial joint, absent incus, absent incus and stapes superstructure, and absent incus and stapes including the footplate. 1 Austin 2 defined four groups in the absence of an intact incus: (1) malleus handle present, stapes superstructure present, (2) malleus handle present, stapes superstructure absent, (3) malleus handle absent, stapes superstructure present, and (4) malleus handle absent, stapes superstructure absent. Ossicular fixation most commonly occurs when the malleus head is ankylosed to the attic wall or when tympanosclerosis of the attic is present. Kartush 3 modified Austin s classification of ossicular defects by adding two other groups related to ossicular fixation: (1) ossicle head fixation with all ossicles present, and (2) stapes fixation with all ossicles present. Moretz 4 added still another category, nonclassifiable, to describe unusual situations requiring ossiculoplasty that are not easily included in the other categories. These include lateralized tympanic membrane and some congenital abnormalities.

2 76 Surgical Atlas of Pediatric Otolaryngology Options for Ossicular Reconstruction The many options for ossicular chain reconstruction can be classified into three groups: 1. Autograft prostheses include tissue harvested from the patient and used for reconstructing the ossicular chain. Examples include the patient s own ossicles or cartilage. 2. Homograft prostheses are derived from human donor tissue, screened and treated to avoid transmission of disease, and preserved for later use. Examples include tympanic membrane, ossicles, and cartilage. 3. Allograft prostheses are synthetic and biocompatible. Examples include high density polyethylene sponge (Plasti-Pore), aluminum oxide, ceramic, and hydroxyapatite. 5 Recommended methods of ossicular chain reconstruction are listed in Tables 4 1 to 4 3. Many of the preferred methods attempt to utilize the patient s own tissue; however, when this is not possible, prosthetic devices can be used depending on the remaining ossicle(s). Prosthetic devices are classified according to the desired reconstruction: Incus prostheses are used when the malleus and stapes are present. Incus-stapes prostheses are used when the stapes footplate is present along with an intact malleus. Partial ossicular replacement prostheses (PORPs) are used when the stapes superstructure is intact. Total ossicular replacement prostheses (TORPs) are used when only the stapes footplate is available.

3 Ossiculoplasty 77 Table 4 1 Reconstructive options for ossicular chain discontinuity with ossicles present Site of discontinuity Tympanic membrane / malleus Malleus / incus Incus / stapes Stapes superstructure / footplate Stapes footplate / oval window Recommended reconstructive options Advancement flap Incus interposition Incus interposition Cartilage autograft Mobilization Stapedectomy, tissue graft, and prosthesis Table 4 2 Reconstructive options for ossicular chain discontinuity with ossicles absent Absent ossicle(s) Malleus Incus Stapes superstructure Malleus and incus Incus and stapes superstructure Malleus, incus, and stapes superstructure Recommended reconstructive options Autograft incus Type II tympanoplasty* Autograft cartilage Incus prosthesis Type III tympanoplasty* Autograft incus Incus-stapes prosthesis Autograft cartilage Type III tympanoplasty* PORP Autograft cartilage Incus-stapes prosthesis Autograft cartilage TORP PORP = partial ossicular replacement prosthesis; TORP = total ossicular replacement prosthesis * See Chapter 3 Table 4 3 Reconstructive options for ossicular chain fixation Site of fixation Malleus / incus Incus / stapes Stapes superstructure / footplate Stapes footplate / oval window Recommended reconstructive options Incus interposition Mobilization Incus interposition Mobilization Mobilization Stapedectomy with prosthesis Mobilization Stapedectomy with prosthesis

4 78 Surgical Atlas of Pediatric Otolaryngology ADVANCEMENT FLAP Indications Lateralized tympanic membrane following any method of tympanoplasty, but more often following the lateral graft technique (see Chapter 3 under Tympanoplasty) Anesthetic Considerations In children, the procedure is performed under general anesthesia. Local anesthetic (1% lidocaine with 1:100,000 epinephrine) is infiltrated into all four quadrants of the ear canal (6, 9, 12, and 3 o clock) just lateral to the bony-cartilaginous junction for hemostasis and to enhance the anesthesia. Procedure Coronal view demonstrating the lateralized tympanic membrane (Figure 4 1). A transcanal incision is made just medial to the bony-cartilaginous junction (Figure 4 2A). The wide tympanomeatal flap is elevated (Figure 4 2B). The middle ear is entered by elevating the annulus (Figure 4 3A). The tympanomeatal flap and lateralized tympanic membrane are elevated to expose the entire middle ear space; the flap is attached only to the anterior canal wall (Figure 4 3B). Figure 4 1 Advancement flap for lateralized tympanic membrane. Coronal view showing that the grafted tympanic membrane does not connect to the malleus, which usually results in mild to moderate conductive hearing loss.

5 Ossiculoplasty 79 A B Figure 4 2 A, A wide tympanomeatal flap incision (dashed line) is made just medial to the bony-cartilaginous junction (right ear). B, The tympanomeatal flap is elevated. A B Figure 4 3 A, Middle ear is entered. B, Tympanomeatal flap and lateralized tympanic membrane are elevated to expose the entire middle ear; the flap is only attached to the anterior canal wall.

6 80 Surgical Atlas of Pediatric Otolaryngology The tympanomeatal flap is advanced medially against the malleus, leaving bare bone in the ear canal medial to the bony-cartilaginous junction (Figure 4 4). Gelfoam is placed lateral to the flap and two strips of Adaptic (with antibiotic ointment) are inserted into the medial and lateral canal as packing (Figure 4 5). An addition to the method described above is to incise part of the tympanomeatal flap and insert the handle of the malleus through the incision. This holds the flap against the malleus, but the incision is generally unnecessary if the packing in the external canal rests firmly against the flap. Postoperative Care The packs are removed in 1 week, and the child is re-examined in about 1 month. Figure 4 4 Tympanomeatal flap is advanced medially against the malleus, which leaves exposed bone in the canal wall medial to the bony-cartilaginous junction. Figure 4 5 Coronal view showing tympanomeatal flap advanced onto the tympanic membrane; Gelfoam is placed lateral to the flap and two strips of Adaptic (with antibiotic ointment) are inserted into the medial and lateral ear canal.

7 Ossiculoplasty 81 INCUS INTERPOSITION Indications The most commonly encountered abnormality with the ossicular chain involves the incus. The incus interposition procedure can be utilized when there is either discontinuity or fixation involving the incudomalleal or incudostapedial joint. Anesthetic Considerations The anesthesia is the same as that described for the advancement flap. Procedure A transcanal incision is made just medial to the bony-cartilaginous junction (see Figure 4 2A). The wide tympanomeatal flap is elevated (see Figure 4 2B). The middle ear is entered by elevating the annulus (see Figure 4 3A). Utilizing a right angle or curved needle, the incus is disarticulated from any remaining attachments in the attic. The incus is removed and sculpted (Figure 4 6A). A groove for the malleus handle is created in the articulating surface of the incus body. The facet for the stapes is then created in the body of the incus near its junction with the long process. The incus is inserted between the malleus and stapes superstructure, completing the interposition (Figure 4 6B). Gelfoam is placed lateral to the flap and the ear canal is filled with antibiotic ointment. Postoperative Care After an initial postoperative visit, the child is followed up in 1 month. A B Figure 4 6 Incus interposition. A, The incus is removed and sculpted. B, The sculpted incus is inserted between the malleus and head of the stapes.

8 82 Surgical Atlas of Pediatric Otolaryngology PARTIAL OSSICULAR REPLACEMENT PROSTHESIS (PORP) Indications Ossicular chain abnormality in which an intact stapes superstructure is bridged with a synthetic biocompatible prosthesis to the tympanic membrane, graft, or malleus Anesthetic Considerations The anesthesia is the same as that described for the advancement flap. Procedure A transcanal incision is made just medial to the bony-cartilaginous junction (see Figure 4 2A). The wide tympanomeatal flap is elevated (see Figure 4 2B). The middle ear is entered by elevating the annulus (see Figure 4 3A). The PORP is inserted on the stapes (Figure 4 7). A notch can be made in the prosthesis to secure the PORP and accommodate the stapedial tendon. A cartilage graft can be placed lateral to the prosthesis to aid in prevention of extrusion of the prosthesis. Gelfoam is placed lateral to the flap and the ear canal is filled with antibiotic ointment. Postoperative Care After an initial postoperative visit, the child is followed up in 1 month. A postoperative audiogram is obtained in 2-3 months. A Figure 4 7 Placement of a partial ossicular replacement prosthesis (PORP). A, Surgeon s view of PORP in place. B, Lateral view of the PORP positioned on the stapes head. B

9 Ossiculoplasty 83 TOTAL OSSICULAR REPLACEMENT PROSTHESIS (TORP) Indications Ossicular chain abnormality in which an intact stapes footplate is bridged with a synthetic biocompatible prosthesis to the tympanic membrane, graft, or malleus Anesthetic Considerations The anesthesia is the same as that described for the advancement flap. Procedure A transcanal incision is made just medial to the bony-cartilaginous junction (see Figure 4 2A). The wide tympanomeatal flap is elevated (see Figure 4 2B). The middle ear is entered by elevating the annulus (see Figure 4 3A). The TORP is inserted on the stapes footplate (Figure 4 8). Figure 4 8 Placement of a total ossicular replacement prosthesis (TORP). A, Surgeon s view of TORP in place. B, Lateral view of the TORP positioned on the stapes footplate. A B

10 84 Surgical Atlas of Pediatric Otolaryngology A cartilage graft is placed between the TORP and tympanic membrane to reduce the chance of extrusion (Figure 4 9). Gelfoam is placed lateral to the flap and the ear canal is filled with antibiotic ointment. Postoperative Care After an initial postoperative visit, the child is followed up in 1 month. A postoperative audiogram is obtained in 2-3 months. Figure 4 9 Cartilage graft between the TORP and tympanic membrane.

11 Ossiculoplasty 85 OUTCOMES AND PROGNOSTIC FACTORS Table 4 4 presents a summary of the published data on hearing level and extrusion rate outcomes for various methods of ossicular reconstruction. 2,5 21 Several trends are apparent. Successful closure of the air-bone gap to less than 20 db hearing level is achieved by less than 80% of authors, with TORP results being generally poorer than those for PORP or incus interposition. Furthermore, hearing results tend to worsen with time in nearly all studies that reported serial outcome data. This observation, combined with the nontrivial extrusion rates in some studies, suggests a need for long-term follow-up of all patients after ossiculoplasty. Several prognostic factors for ossiculoplasty success have been reported. Bellucci 22 noted a relationship between outcomes and middle-ear status (never infected, intermittent discharge, unremitting discharge, and cleft palate or nasopharyngeal deformity) and Austin 2 emphasized the availability of the malleus handle and stapes superstructure. Black 23 proposed a combined system using the acronym SPITE for preoperative predictive factors of poor outcome: (S) Surgical complexity of surgery; necessity of scutum and drum repair (P) Prosthetic absence of malleus or stapes; presentation of a 50 db airbone gap (I) Infection chronic otorrhea; myringitis (T) Tissue poor general condition of tissue, referring to extremes of youth (under 5 years) or advanced age (over 70 years); meatoplasty required; poor mucosa of the middle ear (E) Eustachian tube dysfunction eustachian tube dysfunction / middleear effusion present; severely collapsed tympanic membrane Factors that failed to show statistically significant adverse effects in audiologic results included any prior failed surgery, scutum defect repair without tympanic membrane repair, myringoplasty, and staged surgery. Loss of the stapes superstructure was found by both Mills 24 and Smyth and Patterson 25 to be associated with a poorer outcome in ossiculoplasty. In order to achieve success in ossiculoplasty, Smyth and Patterson 25 concluded that the average postoperative air conduction over the speech frequencies (0.5, 1.0, 2.0, and 4.0 khz) must be < 30 db, or the interaural difference must be reduced to < 15 db. Fifteen db corresponds to the cross-attenuation effect of the skull. 26 If these criteria are not met, the patient will likely be unaware of any audiometric improvement. Reasons for Ossiculoplasty Failure Ossiculoplasty failure may occur because of problems with the prosthesis, middle ear, or eustachian tube. A common cause of ossiculoplasty failure is inadequate contact between the prosthesis and the graft, which may be caused by sliding or reabsorption of the cartilage. Additional causes of functional failure include: (1) improperly sized prosthesis (too short), (2) sliding of the prosthesis, (3) fracture of the stapes crura, and (4) contraction and movement of the healing tympanic membrane. Each of these results in poor contact between the footplate and the graft. 27

12 86 Surgical Atlas of Pediatric Otolaryngology Table 4 4 Clinical outcomes of ossicular reconstruction Achievement rate of hearing levels < 20 db (%) Type of prosthesis First author of paper After 1 year After > 1 year Extrusion rate (%) Autograft Incus interposition Nikolaou Jackson 7 68 PORP Incus replacement, Grote 8 83 hydroxyapatite Wehrs 9 85 Incudostapedial joint Schwetschenau Plasti-Pore Colletti Bayazit Goldenberg Jackson Brackmann Smyth Polyethylene Slater Nikolaou Daniels Ceramic Nikolaou Cartilage Chole Hydroxyapatite and Macias Plasti-Pore Chole Black TORP Incus / stapes, hydroxy- Chole apatite and Plasti-Pore Incus / stapes, Grote hydroxyapatite Plasti-Pore Colletti Brackmann Goldenberg Bayazit Polyethylene Nikolaou Slater Ceramic Nikolaou Cartilage Chole 5 65 Hydroxyapatite and Chole Plasti-Pore Macias Malleus / footplate, Colletti hydroxyapatite TM / footplate, Colletti hydroxyapatite Hydroxyapatite and Daniels fluoroplastic PORP = partial ossicular replacement prosthesis; TM = tympanic membrane; TORP = total ossicular replacement prosthesis

13 Ossiculoplasty 87 Middle-ear disease may also cause ossiculoplasty failure. There are many uncertainties in the hostile biological environment associated with surgery for chronic ear disease mucosal disease, middle-ear adhesions, and eustachian tube dysfunction that contribute to failure of the surgery. These abnormalities promote middle-ear effusion, retraction of the tympanic membrane, atelectasis of the middle ear, and extrusion of the graft or prosthesis. Perforation of the tympanic membrane, with or without extrusion of the prosthesis, may also occur. Eustachian tube dysfunction is also a common cause of tympanic membrane perforation and prosthesis extrusion, because of graft retraction and increased tension against the prosthesis. Sustained tension may break the prosthesis, or result in partial or complete extrusion. One proposed method to decrease failure is to cut the tensor tympani tendon during ossicular reconstruction. This may flatten and slightly lateralize the tympanic membrane, thereby facilitating placement of the prosthesis and decreasing the tendency of the tympanic membrane to medialize in patients with eustachian tube dysfunction. 16 RECOMMENDATIONS FOR OSSICULOPLASTY IN CHILDREN Few studies of ossicular reconstruction in children have been reported. Silverstein et al 28 reported 18 cases using Plasti-Pore PORPs and TORPs, but obtained poor results with a 44% failure rate and 17% extrusion rate. Conversely, Sheehy 29 and Kessler et al 30 reported using PORPs and TORPs in children with success rates similar to those in adults. In Kessler s study, for example, the mean patient age was 9.8 years and hearing results of an airbone gap < 20 db were noted in 54% of cases with an extrusion rate of 13%. Tos and Lau 31 evaluated autografts and homografts in children and found 58% had hearing results of an air-bone gap < 20 db which remained stable. Due to the lack of long-term use of middle-ear prostheses in children, autograft materials are primarily used to reconstruct the ossicular chain whenever possible. 32 The most effective method of managing ossicular chain abnormalities is disease prevention, ie, tympanic membrane retraction treated with placement of a ventilation tube, cartilage graft, or both (see Chapters 1 and 3). The hesitancy to perform ossiculoplasty in children is primarily related to eustachian tube dysfunction with difficulty in controlling middle-ear disease and cholesteatoma. With some reported failure rates higher in children than in adults, many argue that ossicular reconstruction should be be postponed. 10 The principles of successful tympanoplasty, however, are similar for adults and children. Once the child s ear is made safe and stable, ossicular reconstruction is the next goal and completes the restoration of normal middle-ear function. Some claim that children differ only in that they may be more likely to require postsurgical tympanostomy tube insertion to maintain a stable ear. 31,33 Despite a paucity of studies that have evaluated short- and long-term outcomes of ossiculoplasty in children, the surgeon must have some guidelines for procedure timing. A useful rule of thumb is that eustachian tube function may be considered adequate for ossiculoplasty when there has

14 88 Surgical Atlas of Pediatric Otolaryngology been no otitis media (in an ear with an intact tympanic membrane) for at least four consecutive seasons (12 months). This should minimize the incidence of postoperative atelectasis or middle-ear effusion, which can result in failure or extrusion. Similarly, ossicular reconstruction in children who have had a cholesteatoma removed from the middle ear is usually withheld until the middle ear is found to be free of disease (eg, at the time of second look tympanotomy), because residual or recurrent cholesteatoma at the site of the reconstruction will usually result in failure of the graft or prosthesis. Nonetheless, the timing and treatment option chosen should be individualized for each child. REFERENCES 1. Hough J. Incudostapedial joint separation: etiology, treatment and significances. Laryngoscope 1959;69: Austin DF. Ossicular reconstruction. Otolaryngol Clin North Am 1972;5: Kartush JM. Ossicular chain reconstruction: capitulum to malleus. Otolaryngol Clin North Am 1994;27: Moretz WH Jr. Ossiculoplasty with an intact stapes: superstructure versus footplate prosthesis placement. Laryngoscope 1998;108: Chole RA, Skarada DJ. Middle ear reconstructive techniques. Otolaryngol Clin North Am 1999;32: Nikolaou A, Bourikas Z, Maltas V, Aidonis A. Ossiculoplasty with the use of autografts and synthetic prosthetic materials : a comparison of results in 165 cases. J Laryngol Otol 1992;106: Jackson CG, Glasscock ME III, Nissen AJ, et al. Ossicular chain reconstruction: the TORP and PORP in chronic ear disease. Laryngoscope 1983;93: Grote J. Reconstruction of the middle ear with hydroxyapatite implants: long-term results. Ann Otol Rhinol Laryngol 1990;144 Suppl: Wehrs RE. Incus interposition and ossiculoplasty with hydroxyapatite prostheses. Otolaryngol Clin NA 1994;27: Schwetschenau EL, Isaacson G. Ossiculoplasty in young children with the Applebaum incudostapedial joint prosthesis. Laryngoscope 1999;109: Colletti V, Fiorino FG, Sittoni, V. Minisculptured ossicle grafts versus implants: long-term results. Am J Otol 1987;8: Bayazit Y, Goksu N, Beder L. Functional results of Plasti-Pore prostheses for middle-ear ossicular chain reconstruction. Laryngoscope 1999;109: Goldenberg RA. Hydroxylapatite ossicular replacement prostheses: preliminary results. Laryngoscope 1990;100: Brackmann DE, Sheehy JL, Luxford WM. TORPs and PORPs in tympanoplasty: a review of 1042 operations. Otolaryngol Head Neck Surg 1984;92: Smyth GD. Five year report on partial ossicular replacement prostheses and total ossicular replacement prostheses. Otolaryngol Head Neck Surg 1982;90: Slater PW, Rizer FM, Schuring AG, Lippy WH. Practical use of total and partial ossicular replacement prostheses in ossiculoplasty. Laryngoscope 1997;107:

15 Ossiculoplasty Daniels RL, Rizer FM, Schuring AG, Lippy WL. Partial ossicular reconstruction in children: a review of 62 operations. Laryngoscope 1998;108: Macias JD, Glasscock ME III, Widick MH, et al. Ossiculoplasty using the Black hydroxyapatite hybrid ossicular replacement prostheses. Am J Otol 1995;16: Black B. Design and development of a contoured ossicular replacement prosthesis: clinical trials of 125 cases. Am J Otol 1990;11: Brackmann DE, Sheehy JL. Tympanoplasty with TORPs and PORPs. Laryngoscope 1979;89: Colletti V, Fiorino FG. Malleus to footplate prosthetic interposition: experience with 265 patients. Otolaryngology Head Neck Surg 1999;120: Bellucci RJ. Dual classification of tympanoplasty. Laryngoscope 1973;83: Black B. Ossiculoplasty prognosis: the SPITE method of assessment. Am J Otol 1992;13: Mills RP. The influence of pathological and technical variables on hearing results in ossiculoplasty. Clin Otolaryngol Allied Sciences 1993;18: Smyth GD, Patterson CG. Results of middle ear reconstruction: do patients and surgeons agree? Am J Otol 1985;6: Browning G. Clinical Otology and Audiology. London, England: Butterworths; Sellari-Franceschini S, Piragine F, Bruschini P, Berrettini S. TORPS and PORPS: causes of failure. Am J Otol 1987;8: Silverstein H, McDaniel AB, Lichtenstein R. A comparison of PORP, TORP, and incus homograft for ossicular reconstruction in chronic ear surgery. Laryngoscope 1986;96: Sheehy JL. Cholesteatoma surgery in children. Am J Otol 1985;6: Kessler A, Potsic WP, Marsh RR. Total and partial ossicular replacement prostheses in children. Otolaryngol Head Neck Surg 1994;110: Tos M, Lau T. Stability of tympanoplasty in children. Otolaryngol Clin N Am 1989;22: Bluestone CD, Stool SE, Kenna M. Pediatric Otolaryngology. 3 rd ed. Philadelphia: WB Saunders; Chandrasekhar SS, House JW, Devgan U. Pediatric tympanoplasty. A 10 year experience. Arch Otolaryngol Head Neck Surg 1995;121:873 8.

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