652KB Sizes 1 Downloads 63 Views


0030-6665/99 $8.00 + .OO

OTITIS MEDIA WITH EFFUSION AND EARLY SEQUELAE Flexible Approach Matthew Patterson, MD, and Michael M. Paparella, MD

Clearly defining the terminology used in a discussion of otitis media (OM)is essential to accurately conveying information about this disease process. This has been recognized by many investigators; in their article "Pathology of chronic otitis media," Meyerhoff et a110 described a classification system for OM that was first proposed by Paparella and Juhn.I2This system recognizes that forms of this disease can be interrelated and occur in a continuum. Paparella and JuhnI2recognized three forms: (1) OM with effusion (OME), (2) chronic OM (COM), and (3) silent OM. They further differentiated OM with effusion into serous (SOM), purulent (POM), and COM, and subdivided serous OM into acute, chronic (CSOM), and mucoid (MOM) disease? 1. OME A. SOM a. Acute b. CSOM c. MOM B. POM 2. COM A. Active B. Inactive 3. Silent OM

From the Cannon Falls Community Hospital, Cannon Falls (MP); and the Minnesota Ear, Head, and Neck Clinic, Minneapolis (MMP), Minnesota ~~







Serous OM is the result of collection of transudative fluid in the middle ear space. This condition may be either acute or chronic. MOM is the result of active secretion by secretory cells, goblet cells, and subepithelial glands. Although these secretions are nonpurulent, they produce effusions in the middle ear (MEE) that are thicker than in other SOM.IoPOM involves suppuration of the middle ear cleft, with erythema and bulging of the tympanic membrane. COM is an inflammatory process within the middle ear cleft and is associated with irreversibly pathologic tissue. This process may be active and may involve a continuing suppuration, or it may be inactive and demonstrate sequelae of a previous infection.12 Histopathologic studies of OM led to a publication by Paparella et all4 that described the characteristics of the continuum of various conditions in patients with OM. This 1991 publication in La yngoscope detailed morphometric studies that supported the hypothesis that early forms of OM can evolve into more chronic forms. This group recognized that OME usually, with proper treatment, completely resolves to normality but that chronic forms, especially MOM, can lead to sequelae in both the middle ear and inner ear. These sequelae may include hearing loss, pathologic ossicular changes, and tympanosclerosis. Furthermore, they recognized that MOM can evolve into COM, CSOM, and mastoiditis. In that study, Paparella et all4also described the condition of silent OM, first described by Paparella et all5in 1980. They reported that their investigations had revealed that COM and MOM could lead to a condition that they termed silent OM. Investigators had long recognized that mastoiditis resulted from COM and MOM. In addition to being associated with a chronic perforation of the tympanic membrane and a history of otorrhea, this condition is classically identified by the chronically pathologic tissue present in the middle ear and mastoid air cells. Silent OM, Paparella et all4reported, is a condition that can also result from COM and MOM. This condition is characterized by intractably pathologic tissue (i.e., cholesteatoma, granulation tissue, and cholesterol granuloma) behind an intact tympanic membrane.14 Paparella et a l l 3 described that the clinical symptoms of this condition may include conductive hearing loss, sensorineural hearing loss, mixed hearing loss, pressure, pain, acute exacerbations of OM, labyrinthine fistulas, or endolymphatic hydrops.I3


The various types of OM have been classified by Paparella et all4according to the characteristics of effusions in the middle ear and the presence or absence of irreversibly pathologic changes in mucosa of the middle ear (i.e., granulation tissue, cholesterol granuloma, cholesteatoma, or ossicular erosion). These investigators recognized that combinations of these various types of OM were often simultaneously present in the temporal bones that they examined. In their 1990 publication in Annals of Otology, Rhinology and La yngology, Yoon et all9 reported the results of morphometric studies of the continuum of OM that indicated that mucoid effusions can develop from COM. They identified numerous examples of patients with MOM who had histories of CSOM and recurrent POM. This concept of a continuum of OM had first been proposed in 1977 by Juhn et aL8In their 1977 presentation to the American Otological Society in Boston, they reported the results of longitudinal and parallel animal and human studies that supported this hypothesis. These studies focused on the chemical and pathologic evaluation of three essential components in OM: (1) fluids in the middle ear, (2) epithelium of the middle ear, and (3) subepithelium of the middle ear. The



study recognized that POM, SOM, MOM, and COM affect not only the epithelium but also subepithelial tissues. Edema and capillary engorgement are particularly important in the development of POM and SOM. This study also recognized that defense mechanisms of the body seem to originate largely from the subepithelium. An initial increase in the population of neutrophils occurs in this area because of increased phago-c activity. A subsequent increase in plasma cells and lymphocytesoccurs. These lymphocytes release immunoglobulinsinto subepithelial tissue. Epithelial changes, such as hyperplasia and metaplasia and promotion of production of secretory cells, are most prominent in MOM and COM. These epithelial changes are most often seen in cases of chronic infection. Friedman4was one of the first investigators to characterize changes in mucoperiosteum of the middle ear associated with OM. The release of lactate dehydrogenase and lysozymes seems to correlate with the degree of infection in the middle ear. Production of mucopolysaccharides from goblet cells is also characteristically a result of OM. Goycoolea et a16and Juhn et als reported further animal studies demonstrating the continuum of events from serous or purulent effusion to mucoid effusion and, finally, to chronic pathologic conditions or sequelae. The 1990 human histopathologic study by Yoon et all9 revealed that epithelial and subepithelial layers of mucoperiosteum of the middle ear are actively involved in all stages of OM. Furthermore, they indicated that acute inflammatory changes are usually seen in patients with POM and SOM, whereas chronic inflammatory changes are more severe in patients with MOM and COM. Finally, these studies showed overlaps in histopathologic findings among the various types of OM that suggest a continuum of types, with POM or SOM progressing to become MOM and eventually COM. Chemical and cellular activity in the fluids, epithelium, and subepitheliumof the middle ear underlies all forms of OM. The extent of involvement in one or the other of these areas dictates the type of OM present in the middle ear cleft. Evidence for a continuum of OM has been demonstrated in animal models and in human studies. A progression of disease beginning as SOM, developing into MOM, and finally becoming COM has been demonstrated by Juhn et a1.8 These investigators identified many factors in the pathogenesis of OM, including virulence of the offending organism, the role of the eustachian tube (ET), genetics, environmenta1conditions, and allergies. FLEXIBLE SURGICAL TECHNIQUES

Patients who suffer from COM may have other concurrent conditions, including dysfunction of the ET, cholesteatoma or granulation tissue in the middle ear, chronic adenoid hypertrophy, congenital abnormalities of the ear, chronic sinusitis, chronic nasal obstruction, nasal and sinus sequelae of allergies, septa1deviation, or hypertrophied nasal turbinates. The ET is a link between the middle ear cleft and the nasopharynx, nasal passages, and sinuses. This interconnection must be considered when medical or surgical therapy for chronic ear disease is planned. Myringotomy and Tubes, and Adenoidectomy When Indicated

”Acute otitis media and otitis media with effusion are the most commonly diagnosed diseases in infants and children” according to Bluestone in his chapter



entitled “Otitis media,” found in Current Therapy in Otolayngology/Head and Neck Surgery.’ Bluestone continues that when the OM is recurrent or chronic, further evaluation is required, including an evaluation of respiratory allergies and evaluation for chronic sinusitis. He further states that, because some individuals continue to have recurrent episodes of acute OM and chronic OME despite the use of prophylactic or repeated doses of acute antibiotic therapy, myringotomy and the placement of tubes may be necessary. He indicates that adenoidectomy may also play a role in therapy for patients with recurrent acute OM or chronic OME but that it should be used selectivelyand performed in conjunctionwith myringotomy tubes in patients with both OM and chronic nasal obstruction. Paparella and Froymovich1’concur with many of the concepts put forth by Bluestone; in the 1994 Annals of Otology, Rhinology, and Layngology, they proposed guidelines for the placement of myringotomy tubes and use of adenoidectomy. For patients afflicted with recurrent acute POM, especially those 5 years of age or less, these investigators support the use of myringotomy tubes. Like Bluestone, they support the performance of a simultaneous adenoidectomy procedure when clinical symptoms of chronic nasal obstruction and physical evidence of adenoidal hypertrophy are present. For patients suffering from CSOM, they also advocate use of myringotomy tubes. They suggest that conservative therapy be used for 2 months or more before the use of this surgical treatment modality. For the treatment of patients with MOM, Paparella and Froymovichll advocate conservative medical therapy for at least 2 months. If the condition persists, they advocate myringotomy and the insertion of tubes. Adenoidectomy is recommended if findings such as mouth breathing, adenoidal facies, and adenoidal hypertrophy (evidenced by lateral radiograph) are identified. In their 1996 publication in Operative Techniques in OtolaryngologylHead and Neck Surgery, Lee and Lee2 proposed the following guidelines for placement of myringotomy and tubes. Myringotomy and tubes, according to these investigators, should be considered in patients with OME or COM when associated with the following conditions: chronic hearing loss of greater than 30 dB, vertigo, tinnitus, atelectasis of the tympanic membrane, effusions persistent for 3 months or longer, or recurrent acute infections numbering six or more during the past year. The authors’ method for myringotomy and procedure for insertion of tubes is performed by making a radial incision in the anterosuperior quadrant of the tympanic membrane adjacent to the malleus and above the umbo. The tube is placed in this area so as to avoid contact with the ossicular chain that is located behind the posterosuperior aspect of the tympanic membrane and so as to place the tube in approximation to the opening of the ET into the middle ear cleft. It is placed with space beneath it near the protympanum and in a “valley,” not on a “hill,“ such as the promontory, to avoid rapid extrusion. Also, placing the tube medially and as close as possible to the manubrium delays radial migration of the tube so that it may not occur too soon. The authors’ policy, in general, is not to remove tubes but to allow natural healing to occur.

Cauterization of Inferior Turbinates and Dilatation of the Sinus Ostia

In a 1996 publication of Operative Techniques in Otolayngologylffead and Neck Surgery, DeSouza and coworkers3state that the effects of changes in the nose and paranasal sinuses are often felt in the middle ear and that OM is frequently secondary to dysfunction of the ET resulting from such nasal and sinus disease. They



conclude that it is logical to treat nasal and paranasal sinus disease when it is clinically evident that these processes are a contributing cause of OM. These investigators proposed that surgery to correct nasal and paranasal sinus problems restores the normal functioning of the nose and paranasal sinuses, prevents these problems from affecting the ET, and assists in the treatment of patients with OME or COM. DeSouza and colleagues3also proposed that pathologic nasal conditions can cause OM as a result of edema in proximity to the ET and subsequent obstruction of this orifice and by insufflation of contaminated nasal secretions into the middle ear. These investigators support the use of surgical procedures, such as septoplasty, turbinoplasty, creation of nasal antral windows, and endoscopic sinus surgery, to correct anatomic conditions that result in chronic and recurrent nasal and sinus disease and thereafter in OM. Use of Paparella Type 2 Tubes

Myringotomy tubes usually remain in position for 9 to 12 months or longer. In many cases, this period of time is sufficient to allow for the return of normal functioning in the ET and a healthy middle ear. In other cases, functioning of the ET may remain abnormal, and these patients may require more prolonged treatment for disease in the middle ear, especially in obstinate cases of intractable MOM. In such circumstances, a Paparella type 2 myringotomy tube (Smith and Nephew, Bartlett, Tennessee) may be useful. Paparella and Froymovich" found that such tubes infrequently caused chronic perforations of the tympanic membrane and that their ability to maintain ventilation of the middle ear cleft for a prolonged period of time greatly assisted in the treatment of patients with chronic dysfunction of the ET.12 Frequently, the authors trim the inner phalange of the tube to a smaller, butterfly shape to suit individual anatomic and pathologic circumstances. Myringoplasty

Perforations of the tympanic membrane may occur as a sequela of OM. Myringoplasty can be performed under certain circumstances in an effort to repair such a sequela in clean, dry ears with no evidence of underlying disease in the middle ear. This transcanal procedure can be performed with the patient under local or general anesthesia. Indications for Endaural Tympanoplasty for Atelectasis, Perforated Tympanic Membranes, and Retraction Pockets

The first described attempt to close a perforation of the tympanic membrane was reported in medical literature of the seventeenth century by Banzer.'* Since that time, a variety of techniques and approaches have been developed to achieve this objective. Materials used for the grafting of perforations of the tympanic membrane indude fascia temporalis, tragal perichondrium, retroauricular connective tissue, and retroauricular periosteum. The approaches that can be used for performing tympanoplastic procedures include the postauricular, transcanal, and endaural approaches. Paparella and Froymovich" advocate use of the endaural approach to tympanoplasty because of the flexibility of the approach. Using such a technique, the



procedure can be adapted most easily when addressing various disease processes as they may be identified during the operation. If significant disease is identified extending into the mastoid air cells, the procedure can easily be converted to a tympanomastoidectomy. If a canalplasty is needed to properly visualize the middle ear space, this can easily be accomplished using the flexible appr0a~h.I~ When OME leads to atelectasis of the tympanic membrane, the flexible surgical approach can be used to perform a tympanoplasty. Paparella described this technique in a 1979 article in Laryngoscope: ”Tympanoplasty for atelectatic ears.”I6 He advocated widening the middle ear cleft by carefully drilling down the posterior bony wall of the canal at its medial extent. The attic is carefully explored, and the thin epithelium that has often collapsed onto the promontory of the middle ear is carefully preserved. If necrosis of the lenticular process is identified, then an ossiculoplasty is performed. If the tensor tympani tendon is fixed, then it is severed. This allows for mobilization of the malleus and widening of the mesotympanic space. The malleus is often adherent to the promontory. When the ossicles have been reconstructed and the thin tympanic membrane elevated, a cresent-shaped piece of silicone sheeting is placed in the middle ear, extending from the opening of the ET to the sinus tympani to the round window niche. The graft of the tympanic membrane is laid beneath the thin layer of epithelium that was previously elevated from the promontory. A myringotomy tube is placed in the anterior remnant of the drumhead. This procedure not only addresses the functional deficits present but also prevents further progression of the disease process.I6 The repair of chronic perforations of the tympanic membrane resulting from OM can also be effected using the flexible surgical approach described by Paparella.I6This approach is particularly appropriate because disease that was not recognized during preoperative examination of the patient is not uncommonly identified intraoperatively when repairing such perforations. The flexible approach allows for the procedure to be easily modified to allow for the appropriate treatment of previously unrecognized disease processes. The flexible approach allows for grafts on the tympanic membrane to be laid as underlays, as double-layered grafts, or as lateral grafts, depending on the needs of the particular situation. When performing repair of a perforation of the posterior tympanic membrane, an underlay graft is often appropriate. The edges of the perforation are trimmed, the undersurface of the membrane is gently scraped, and the membrane is de-epithelialized in the area where the graft is to come in contact with the tympanic membrane around the perforation. For perforations of the anterior tympanic membrane where only the annulus remains, anteriorly, support for the fascia1 graft is provided by gelatin sponge packing placed beneath the graft. Raising an anterior skin flap may aid in properly positioning the graft, and the graft is positioned beneath this flap and beneath the remnant of the annulus in a manner identical to the placement of an underlay graft for a posterior perforation. A retraction pocket is a medial displacement of a portion of the tympanic membrane that may eventually result in the formation of a cholesteatoma and may promote the growth of granulation tissue, chronic purulent infection, and otorrhea. Deep retraction pockets harboring squamous debris and infection often result in erosion of the ossicles. Levinsongadvocates surgical intervention for the treatment of retraction pockets when one or more of the following conditions occur: persistent or recurrent otorrhea; persistent granulation tissue; a conductive hearing loss of more than 20 dB; development of a noncleansing pocket, the limits of which cannot be adequately assessed; or identification of overt cholesteatoma. Levinson supports the use of a cartilage perichondrial graft to support and stiffen the retraction pocket structurally.



A flexible approach can be used to perform repair of the tympanic membrane, and it is ideal for allowing additional procedures to be performed in the event that previously unrecognized pathologic conditions are observed during the surgical procedure. After the retracted region of the tympanic membrane and all associated diseased tissue has been elevated and removed, a graft is harvested from tragal cartilage. The perichondrium is stripped from the convex side of the cartilage, and the composite graft is thinned as needed. In the usual case in which the retraction pocket involves the posterosuperior quadrant of the tympanic membrane, the graft is fitted to bridge the area from the manubrium to the posterior wall of the canal. If the retracted area extends anteriorly to the manubrium or inferiorly into the hypotympanum, the graft is positioned to address these areas. Flexible (Conservative Surgical) Approach for Chronic Otitis Media

Recurrent or chronic infection and persistent hearing loss are but a few of the indications that a procedure more extensive than a myringotomy and insertion of tubes or than a tympanoplasty must be considered so as to treat the sequelae of OM.’] For many of these patients, mastoidectomy procedures are recommended. An alternative approach to this invasive form of therapy has been devised by Paparella et al.’ They advocate the use of a conservative, flexible technique because of its ability to provide sequential assessment of the pathologic and anatomic variables in the disease process, thus allowing the use of only those conservative surgical steps necessary in each case. Studies of the temporal bone have shown that the pathogenesis of COM can be influenced by anatomic variants or by pathologic sites of obstruction in the middle ear. Areas such as the protympanum, mesotympanum (prominent promontory or retracted malleal handle), isthmus, attic, aditus ad antrum, and the mastoid air cells can be sites of such pathologic conditions. In many patients with COM, the promontory may be especially lateral in its projection and the handle of the malleus retracted. This can lead to mesotympanic block. Histologically, the tensor tympani muscle has been shown to demonstrate inflammatory cell infiltration and fibroblastic reaction to COM. This may result in spasm or contracture of the muscle and retraction or fixation of the tympanic membrane and ossicles. Such a condition results in narrowing of the mesotympanum. Hypertrophic mucosal folds or granulation tissue in the isthmus and attic can obstruct the middle ear as well. Obstruction of the aditus ad antrum can lead to pathologic tissue in the mastoid cavity, a condition termed aditus block. Other developmental abnormalitiesin the temporal bone, such as a narrowed meatus and auditory canal, can also contribute to the progression of disease in the middle ear cleft by preventing proper visualization of the ear during examination. The middle ear cleft may be anatomically small, or a low-hangingtegmen tympani or tegmen mastoideum may be present. These conditions can contribute to anatomic obstruction in the middle ear space and development of OM.7The flexible surgical approach to the treatment of patients with COM and its sequelae, advocated by Paparella and others,” allows for the treatment of any of these contributing causes of OM as they are identified during the surgical procedure. Incisions An endaural approach via Lempert I, 11, and 111incisions is used to allow for adequate exposure.



Exploratory Tympanotomy

After a tympanomeatal flap has been elevated, the annulus is elevated and the middle ear is entered to look for obstructed sites, thickened mucosa, granulation tissue, and the like. If a retracted malleus has led to mesotympanic obstruction, the tensor tympani tendon is cut and the malleus and tympanic membrane are lateralized. In some patients with persistent COM, exploratory tympanotomy and reconstruction of the middle ear (with insertion of a myringotomy tube) is sufficient to allow for the resolution of disease in the middle ear?


A canalplasty is important in alleviating obstruction of the auditory canal that prevents proper visualization of the middle ear space. If the middle ear space cannot be properly visualized, then the extent of the disease process cannot be accurately assessed, and the condition cannot be surgically treated. In such cases, a canalplasty is useful in achieving proper visualization. The bony canal is drilled down to allow for proper exposure of the mesotympanum. The several mastoid air cells that may be encountered when drilling the posterior canal wall allow for an initial evaluation of pathologic conditions in this area. Anteriorly, a laterally based flap of canal skin is elevated retrograde to allow for drilling of the anterior bony canal wall. Care must be used to avoid violation of the capsule of the temporomandibular joint.7

A tticotomy

When sufficient visualization has been established and the tympanomeatal flap has been elevated, the middle ear cleft can be more adequately visualized. If disease is identified extending into the epitympanum and attic, then an atticotomy is appropriate. A stapedial curette can be used to remove the posterior canal wall at its medial extent. An atticotomy is performed according to the needs of the particular patient, allowing for full visualizationof the middle ear space, including the attic and the epitympanum.17


If disease is suspected in the mastoid cavity, and if the patient has adequate mastoid pneumatization (identified by preoperative radiographic evaluation), then the fossa mastoideum is identified and removed with a large burr. The aditus ad antrum is also cleared of all pathologic t i s s ~ e . ~


A canal wall-up, canal wall-down, or intact-bridgemastoidectomy(IBM)may be the next step in treatment of a diseased ear. The IBM was developed to maximize the advantages and minimize the disadvantages of the other two techniques. In the IBM, an open mastoidectomy leaves the bridge intact, along with its continuous facial buttress, sufficiently high to increase the posterior mesotympanic space.7



Reconstruction of the Middle Ear or Ossiculoplasty

The diameter of the middle ear is enlarged, as indicated, using an ample posterior bony atticotomy. The mesotympanum may be deepened by lateralizing the malleus. After all of the pathologic tissue is removed, ossiculoplasty is performed. Healthy, usable ossicles (when present) are mobilized, or partial or total ossicular replacement prostheses are placed. To prevent adhesions, silicone is placed between the undersurface of the grafted tympanic membrane and the medial wall of the middle ear cleft. A tube is placed in the remnant portion of the anterior aspect of the tympanic membrane. This is used to compensate for dysfunction of the ET.7 Meatoplasty

A meatoplasty is performed as necessary to provide adequate visualization of the tympanic membrane postsurgically. Identification of recurrent disease is dependent on proper visualization of the ear, and creation of an external auditory canal and meatus adequate for this purpose is essential in the overall treatment of the disease process. A wide meatoplasty is essential in cases in which an opencavity or an IBM has been performed. Using sharp dissection, a generous piece of concha1 cartilage is removed. Little skin needs to be removed, and the skin can be appropriately used to line a mastoid bowl if this has been created.I9 Thiersch Graft

If significant unhealed areas remain 2 to 4 weeks after canalplasty or mastoidectomy, an outpatient Thiersch grafting may be performed to cover this area with an epithelial lining7 SUMMARY

Patients suffering from chronic otitis media often have a variety of associated disease processes and pathologic conditions. These conditionsand processesrange from cholesteatoma to eustacian tube dysfunction. The identification and recognition of the factors contributing to the disease process of chronic otitis media are critical to the effective treatment of the condition. Familiarization with conditions associated with chronic otitis media, the disease process, and the guidelines for surgical therapy is also essential. Furthermore, this surgical therapy is designed to provide surgeons with a technique that allows sequential assessment of the pathologic and anatomic variables in the disease process, thus allowing the use of only those conservative surgical steps necessary in each case. References 1. Bluestone C:Otitis media. In Gates G (ed): Current Therapy in Otolaryngology/Head

and Neck Surgery. St. Louis, Mosby-Year Book, 1994, pp 11-16 2. Lee CS, Lee HS: Tympanostomytubes: Use and problems. Operative Techniques in Otolaryngology Head and Neck Surgery 79-16,1996 3. DeSouza C, Bhaya M, Wagh SF: The role of nasal and sinus surgery in otitis media. Operative Techniquesin OtolaryngologyHead and Neck Surgery 716-17,1996 4. Friedman I: Pathology of the Ear. Oxford, Blackwell Scientific, 1974, p 128 5. Gooycoolea M, Paparella MM, Nissen R Tympanoplasty.In Atlas of Otologic Surgery. Philadelphia, Wl3 Saunders, 1989, pp 218-243 6. Goycoolea MV, Paparella MM, Carpenter AM, et al: A longitudinal study of cellular changes in experimental otitis media. Otolaryngol Head Neck Surg 87685-700,1979



7. Harvey S, Paparella MM, Sperling N, et al: The flexible (conservative surgical) approach for chronic otitis media in young children. Laryngoscope 102:1399-1403,1992 8. Juhn SK, Paparella MM, Kim CS, et al: Pathogenesis of otitis media. Ann Otol Rhinol Laryngol86:481-492,1977 9. Levinson RM: The management of granular myringitis and retraction pockets. In Nadol JB, Schuknecht HF (eds): Surgery of the Ear and Temporal Bone. New York, Raven Press, 1993, pp 139-144 10. Meyerhoff W, Kim C, Paparella Mh4: Pathology of chronic otitis media. Ann Otol Rhinol Laryngol87749,1978 11. Paparella MM, Froymovich 0 Surgical advances in treating otitis media. Ann Otol Rhinol Laryngol103 (suppl163):49-53,1994 12. Paparella MM, Juhn SK Otitis media: Definition and terminology. Presented at the Second National Conference on Otitis Media, Scottsdale, AZ,1978 13. Paparella MM, Kimberley BP, Alleva M: The concept of silent otitis media: Its importance and implications. Otolaryngol Clin North Am 24:763-774,1991 14. Paparella MM, Schachern PS, Sano S, et al: A histopathological study of the relationship between otitis media and mastoiditis. Laryngoscope 101:1050-1055,1991 15. Paparella MM, Shea D, Meyerhoff WL: Silent otitis media. Laryngoscope 90:1089,1980 16. Paparella MM. Tympanoplasty for atelectatic ears. Laryngoscope 89:1345-1246,1979 17. Sajjadi H, Paparella MM: Intact-bridge mastoidectomy: Operative techniques. Operative Techniques in Otolaryngology Head and Neck Surgery 716-55,1996 18. Shambaugh GE Jr: Surgery of the Ear, ed 2. Philadelphia, WB Saunders, 1967, p 430 19. Yoon TH, Schachem PA, Paparella MM, et al: Morphometric studies of the continuum of otitis media. Ann Otol Rhinol Laryngol99(suppl148):23-27,1990

Address reprint requests to Matthew Patterson, MD Cannon Falls Community Hospital 1116 West Mill Street Cannon Falls, MN 55009