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Endoscopic management of cholesteatoma
Endoscopic management of cholesteatoma: Long-term results MUAAZ TARABICHI, MD, Dubai, United Arab Emirates
OBJECTIVES: This report evaluates long-term results of transcanal endoscopic management and surveillance of cholesteatoma. METHODS: Sixty-nine ears with acquired cholesteatoma underwent endoscopic transcanal tympanotomy and atticotomy to access and completely remove the sac. Reconstruction with a composite tragal graft was performed in 38 ears, and the cavities were packed open in 31 ears. Office-based endoscopic surveillance and follow-up were performed. RESULTS: Forty-three ears were operated on with the patient under local anesthesia, and 58 were done on an outpatient basis. Three cases were converted into postauricular tympanomastoidectomy. There were no iatrogenic facial nerve injuries. Bone thresholds were stable, except in 1 patient with perilymphatic fistula. Mean follow-up was 41 months, and 19 ears underwent 5 years of follow-up. Six ears required revision surgery, and 9 required officebased minor procedures. CONCLUSIONS: An endoscopic technique allows transcanal, minimally invasive management and surveillance of cholesteatoma with long-term results that compare well to those of postauricular methods. (Otolaryngol Head Neck Surg 2000;122: 874-81.)
T
he use of the endoscope in ear surgery has been gaining acceptance as an adjunct to traditional microscopic surgery, and many investigators have reported their experience on the subject.1-8 During the last 6 years I have relied on the endoscope as the central instrument to perform middle ear9 and cholesteatoma surgery.10 From the Division of Otolaryngology, American Hospital-Dubai. Presented at the Annual Meeting of the American Academy of Otolaryngology–Head and Neck Surgery, San Antonio, TX, September 13-16, 1998. Reprint requests: M. Tarabichi, MD, Division of Otolaryngology, American Hospital-Dubai, PO Box 5566, Dubai, United Arab Emirates. Copyright © 2000 by the American Academy of Otolaryngology– Head and Neck Surgery Foundation, Inc. 0194-5998/2000/$12.00 + 0 23/77/102111 doi:10.1067/mhn.2000.102111 874
This follow-up report discusses the long-term results with endoscopic management of acquired cholesteatoma. METHODS Instrumentation The endoscopes used were primarily 4-mm, wide-angle (20-cm-long) 0° and 30° sinuscopes. Other smaller diameter scopes were used sparingly. Video equipment included a 3-chip videocamera and monitor. All of the procedures were performed directly off the monitor and were recorded. As for instruments, initially, most picks, elevators, and curettes were modified with a 20° deflection at 1 cm from the tip of the instrument. During the past year, Otoview instruments (Smith & Nephew Richards, Memphis, TN) were used in conjunction with routine microscopic ear surgery instruments. Operating room setup was as follows. The monitor was placed on the other side of the table across the patient’s head. A Mayo stand was used to hold the camera and the scope clear from the patient’s head (most of these procedures were done with the patient under local anesthesia). An absorbent pad soaked with antifog solution was pasted on the drapes above the patient’s ear. Preoperative Evaluation Patients underwent traditional microscopic examination and audiometric studies. Also, an office-based endoscopic examination was performed. This experience extended over a few years, and initially, CT scanning of the temporal bone was used sporadically. During the past 2 years, almost all patients have undergone preoperative CT, mainly to determine the extent of disease, the possible need for a postauricular approach, and whether the patient should be offered the option of local anesthesia. Surgical Technique Patients are advised that local anesthesia with intravenous sedation is preferable but are given the option of general anesthesia. The ear canal is infiltrated with lidocaine 1% with 1/60,000 epinephrine. All surgical tasks are performed with the endoscope. A wide posterior tympanomeatal flap is elevated with the superior limb in the 1 o’clock position and the inferior limb in the 6 o’clock position. As the annulus is elevated and the middle ear is entered, the cholesteatoma sac is
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Fig 1. Endoscopic examination showing severe retraction and accumulation of cholesteatoma in the left ear.
elevated off the middle ear structures in continuity with the flap when possible. The sac is then pursued under direct vision, with the bony rim curetted or drilled just enough to continue the dissection process under direct vision. The drilling is usually done either with a microdrill system (Skeeter drill; Xomed-Treace, Jacksonville, FL) or with different sized bone curettes under continuous monitoring with the endoscope. The surgical field is irrigated frequently, and all drilling and curetting are confined to the area superior to an imaginary line that runs over the horizontal segment of the facial nerve and extends posteriorly into the ear canal. The body of the incus and the head of the malleus are preserved or removed based on the extent and location of disease. Depending on the comfort level with the complete removal of cholesteatoma and the health of the middle ear mucosa, the decision is made whether to delay ossicular reconstruction and plan a second-look operation; otherwise, appropriate ossicular chain work is performed, and the attic defect is closed with a composite tragal graft. If the sac extends beyond the attic, aggressive bone removal is carried out to provide open endoscopic access into the attic and all the way posteriorly into the antrum. All squamous epithelium is removed, and the attic and antral defect are packed open. Tympanic membrane defects inferior to the horizontal segment of the facial nerve (including atelectatic areas) are reconstructed with a composite tragal graft, which is placed directly on, and up to, the horizontal segment of the facial nerve superiorly and on a bed of Gelfoam that is packed in the middle ear inferiorly. The
ear canal, along with the open attic, is then packed with Gelfoam. Continuous office-based endoscopic examination and follow-up are performed. Patients who have extensive disease where the antrum and the attic are packed open undergo routine cleaning of the cavities with continuous surveillance for recurrent cholesteatoma and any significant narrowing of the neck of cavity. Office-based procedures include limited curetting of bone and removal of soft tissue, which are performed as needed. The hospital’s ethics committee approved this study, and informed consent was obtained from patients. RESULTS
All patients had severe retraction with bony erosion, and complete removal of dermal debris could not be accomplished under the microscope. None of the patients had previous ear surgery on the involved ear. Endoscopic office-based examination was incorporated into all routine office evaluations and follow-ups. Sixty-nine ears had acquired cholesteatoma and underwent endoscopic transcanal tympanotomy with extended atticotomy to access and completely excise the cholesteatoma sac. Forty-three procedures were performed with the patient under general anesthesia, and 58 procedures were done on an outpatient basis. None of the patients had previous surgery in the involved ear. Three procedures were converted intraoperatively into traditional postauricular tympanomastoidectomy after an initial endoscopic approach. There were 2 distinct groups of patients.
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Fig 2. Tympanomeatal flap is elevated and middle ear is entered (A). Cholesteatoma sac is identified over the posterosuperior part of the tympanic cavity extending into the antrum and mastoid cavity.
Group 1 included 38 patients with endoscopically accessible disease in which the sac could be easily elevated off the ossicles, middle ear, and attic. The decision to proceed with any needed ossiculoplasty was based on the degree of certainty of the complete removal of disease and the health of the middle ear mucosa. Residual attic and tympanic membrane defects were reconstructed with a composite tragal graft. Group 2 included 31 patients with extensive disease within the mastoid cavity proper. Wide transcanal atticotomy was performed, and the bony defect was enlarged into the antrum and was packed and left open. Residual tympanic membrane defects inferior to the horizontal segment of the facial nerve were reconstructed with composite tragal graft in 9 patients. The tympanic cavity was packed with Gelfoam inferior to the horizontal segment of the facial nerve, and the graft was positioned on top of the Gelfoam inferiorly and immediately on top of the facial nerve and medial wall of the attic superiorly. There were no untoward intraoperative events. The size of the ear canal was not a limiting factor. None of the patients had worsening of sensorineural hearing loss (defined as > 10 dB change in bone conduction thresholds at 500, 1000, 2000, or 3000 Hz), except for 1 patient who had a 15-dB worsening of bone conduction at 3000 Hz. This particular patient had severe sensorineural hearing loss and dizziness that lasted for 1
week before initial evaluation. This patient did have a lateral semicircular canal fistula. There were no incidents of iatrogenic facial nerve injuries in this series. Mean follow-up was 41 months, with 19 ears observed for 5 years. Six ears required revision surgery, with 4 patients undergoing revision endoscopic procedures to convert into an open attic and antrum cavity and 2 patients undergoing classic canal wall down postauricular procedures. All recurrences were mastoid, attic, and antrum recurrences, and there was only 1 case of tympanic cavity disease, which manifested as a small incidental pearl attached to the underlayer of the tympanic membrane. Only 1 operating room– based revision procedure occurred in group B. Nine ears in group B required office-based minor procedures, which included removal of some disease from the open attic, minimal curetting of bony regrowth to open up the closed antrum and attic, and incision of scarred skin and soft tissue (limiting access to the cavity) and deflecting the edges into the underlying open bony cavity. Narrowing of the neck of the cavity was observed only during the first 8 months after surgery, and all 9 office-based procedures were performed during that period of time. There was only 1 case in which the open attic was closed significantly and the ear continued draining. This was addressed with postauricular canal wall down mastoidectomy. All other patients had healthy-looking shallow cavities. There were 19 ears with 5 years’ follow-up
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Fig 3. Sac was removed off the medial wall of the tympanic cavity (oval window, A; facial nerve, B). Sac remnant (C) is left over the lateral semicircular canal.
after an endoscopic approach for removal of a cholesteatoma. Only 2 cases needed operating room–based revision surgery in this group, and this actually occurred during the first 2 years after surgery. In this group of patients, there were 9 cases in which the attic was packed open at the time of surgery, and the residual cavities proved to be shallow, benign, and problem-free areas. CASE REPORT A 52-year-old man had a 1-week history of severe dizziness and hearing loss. He reported a previous history of ear problems but no ear surgery. An audiogram revealed severe sensorineural hearing loss on the left side. Fistula test results were negative. Endoscopic examination of the left ear showed severe retraction of the tympanic membrane and cholesteatoma (Fig 1). With the patient under local anesthesia, a wide tympanomeatal flap was elevated, and a large cholesteatoma sac was identified (Fig 2). The sac was elevated off the middle ear cavity, the medial wall of the middle ear and the round and oval windows were inspected for fistulas, and a remnant of the sac was left over the lateral semicircular canal (Fig 3). The area of the lateral semicircular canal was palpated, and then the sac was carefully removed. A small lateral canal fistula was identified (Fig 4). A graft was positioned over the area, and a composite tragal graft was used to reconstruct the upper part of the tympanic membrane (Fig 5). The attic was packed open. Follow-up examination at 33 years showed a healthy attic and antrum, and the patient did not report any major dizziness symptoms (Fig 6).
DISCUSSION
The introduction of the binocular operating microscope was a landmark event in the development of modern otology, and it clearly changed the scope and character of ear surgery. Despite continuous technical improvements, the basic optical principles, and their limitations, have stayed the same for the last 3 decades. With the introduction of the endoscope into other branches of surgery, there have been attempts to use it in otology. The diagnostic, mostly photographic, role of the endoscope for examining the tympanic membrane and the ear canal has been widely publicized.3 Transtympanic middle ear endoscopy was initially reported by Nomura4 and Takahashi et al.5 Poe and Bottrill6 described transtympanic endoscopy for the confirmation of perilymphatic fistula as well as the identification of other middle ear pathology. McKennan7 described second-look endoscopic inspection of mastoid cavities through a small postauricular incision. Thomassin and Korchia1 reported operative ear endoscopy for mastoid cavities and designed an instrument set to be used in these settings. Other investigators looked at the role of the endoscope in neurotologic procedures.8 Safety Concerns with Endoscopic Ear Surgery Excessive heat dissipation. This was evident only when a xenon light source was used. Adequate illumination of the middle ear space can be accomplished
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Fig 4. Sac is completely removed and lateral canal fistula (E), oval window (G), and facial nerve (D) are identified.
with lower settings on the regular light source (because of the size of the cavity) without the need for xenon systems. Also, the tip of the endoscope requires continuous cleaning with an antifog solution, which probably helps in cooling the endoscope.
wide-angle 0° endoscopes provide excellent visualization of structures such as the ear canal.
Accidental patient movement with secondary direct trauma by the tip of the endoscope. The rel-
sible even when using the 0° endoscope because of the wide angle view of the more recent endoscopes.
atively large diameter of the endoscope used (4 mm) and the anatomy of the ear canal and middle ear space will usually preclude the introduction of the endoscope beyond the tympanic ring. Even in endoscopic stapedectomy, there is less need for curetting the posterior and superior aspects of the canal for exposure; this provides a protective rim that prevents the advancement of the endoscope beyond the tympanic ring.
Ability to visualize past the shaft of larger surgical instruments such as drills and curettes. It is not
Visualization of hidden structures such as an anterior tympanic membrane perforation, sinus tympani, facial recess, attic, and hypotympanum. This is pos-
uncommon in microscopic surgery for the handle of the instrument to prevent visualization of the operative field (after the initial positioning and engagement) and for the surgeon to rely on the feel of the instrument rather than the continuous visualization of the operative field. Disadvantages of Endoscopes
Advantages of Endoscopes Wide angle of view. The endoscopic view usually
includes the whole tympanic ring and ear canal at the same time. In contrast, the field of the microscope is defined by the narrowest segment in the ear canal, therefore requiring continuous manipulation of the microscope and/or the patient’s head. Better visualization of structures that are parallel to the axis of the microscope. It is usually necessary
to position structures at a right angle to the axis of the microscope for adequate visualization, which is difficult or impossible in certain situations. The 30° and the
Loss of depth perception and binocular vision.
This is easily compensated for with experience. In operative endoscopy, the introduction of the instrument into the field and the way it is visualized on the monitor provide tactile and visual cues that are used by the experienced endoscopist to reconstruct a 3-dimensional view of the operative site. Even though newer endoscopes might provide depth perception, this issue is more related to the experience of the surgeon than to the limitations of present day technology. One-handed surgical technique. This is probably the most important issue to deal with in endoscopic ear
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Fig 5. Tragal composite graft (L) is used to reconstruct the upper part of the tympanic membrane over a bed of Gelfoam (E), and the attic and antrum are packed open after the fistula is covered with a fascial graft (not shown).
surgery. Meticulous attention to hemostasis is essential and is easier given the excellent visualization of the ear canal and the ability to cauterize bleeding points along the edges of the incised skin in the canal, the most common site of bleeding in middle ear procedures. With experience, the tip of the endoscope can be used to push or lift certain structures. Further development of endoscopic ear surgery might be enhanced by incorporating other functions into the endoscope. Physician training. Although there is a definite learning curve, acquiring the necessary skills should not be too difficult for the experienced nasal endoscopist. It might be rather hard for established otologists who lack endoscopic training to make the necessary transition. Cost of equipment. Most of the equipment used is available in most operating rooms. The only extra instruments involve very minor modifications of the existing instruments. Fogging and smearing of the tip of the endoscope. This can be handled very easily by rubbing the
tip against the antifog pad that is pasted close to the ear. The fact that the endoscope is used in close contact to the surgical field (to obtain magnification) has never interfered with the surgical task being performed. The surgical management of cholesteatoma has been designed around the advantages and limitations of the surgical microscope, with postauricular exposure as a
critical direct line access into the advancing sac as it reaches the antrum and mastoid cavity. The wide-angle view of the endoscope transforms the surgeon’s perception of the advancing cholesteatoma sac into a mere extension of middle ear and attic disease, with the ability to pursue the sac and remove it through a transcanal approach. The endoscope provides an excellent means of evaluating the middle ear space along with its hard to visualize extensions, including the sinus tympani, facial recess, sinus tympani, and hypotympanum. This represents a clear advantage over the microscopic technique and could be complementary to it when evaluating and treating cholesteatoma with the traditional and timehonored postauricular approach. For most patients the endoscopic technique transformed the ultimate surgical approach and allowed the surgeon to think of the disease process as a retraction pocket rather than a developing cholesteatoma; also, it enabled the surgeon to eradicate disease, reconstruct the sound-conduction mechanism, and close any residual bony or tympanic membrane defect. Thirty-one patients had extensive disease involving the antrum, which was pursued and grossly eradicated. Definitive treatment was accomplished by leaving the attic and mastoid cavity open to the ear canal superiorly and posteriorly while reconstructing the tympanic membrane up to the level of the horizontal segment of the facial nerve with the graft
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Fig 6. Endoscopic examination of the left ear 3 years after surgery showing a manageable and clean cavity.
resting against Gelfoam inferiorly and immediately on top of the medial wall of the attic and facial nerve superiorly. The rationale for the surgical approach in these patients is based on the good results reported by Tos in 1982, when he proposed a different approach to attic cholesteatoma, which he summarized as follows: Since 1970 I have applied my own modification of CAT (Combined-Approach Tympanoplasty) that is based on other surgical principles than the classic CAT and on a new philosophy, i.e., to create such conditions in the attic that the retraction does not necessarily lead to recurrent cholesteatoma requiring reoperation, but most often to a peaceful small cavity with an acceptably wide access. Furthermore, any residual cholesteatoma can be observed through the atticotomy opening, replacing a second look operation.”11
The endoscope offers a better opportunity to accomplish these objectives through a transcanal approach. Given the wide angle of view of the endoscope, it is not necessary to take down the whole posterior wall to maintain the mastoid cavity. These cavities could easily be maintained and inspected with the endoscope in the office, like the open mastoid cavity after canal wall down procedures. It is my experience that such a limited cavity has proved to be manageable and benign and does not require continuous cleaning.
The average operating time was shorter than with the traditional postauricular approach. This could be easily explained by the fact that the pathology is accessed directly through the canal without the need to drill a large cavity as in postauricular mastoidectomy. Good transcanal endoscopic access into the attic and antrum could be provided by removal of a rather limited amount of bone, mostly with a curette or microdrill. The safety of the facial nerve is ensured by the direct identification of the horizontal segment of the facial nerve and by limiting any drilling in the posterior canal to the area superior that. The facial recess is easily explored with the endoscope through a transcanal approach without any drilling or manipulation close to the facial nerve. I have observed 19 ears for 5 years after an endoscopic approach for removal of cholesteatoma and have found only 2 cases in which there was a need for revision surgery in this group, and this actually occurred during the first 2 years after surgery. In this group of patients, there were 9 cases in which the attic was packed open, and the residual cavities proved to be shallow, benign, and problem-free areas. An essential part of the management is continuous outpatient endoscopic follow-up and examination of these cavities; if the neck of the cavity is closing, office-based debridement and curetting should be done to prevent closure. This nar-
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rowing in the neck of the cavity usually occurs during the first year, and if adequately managed, will subside and improve during the following years. Given the ultimate shallowness of these cavities and their benign course, I have been more inclined to leave the attic open rather than reconstruct the attic defect. The lack of any recurrence in the tympanic cavity (only 1 case had a small pearl in the tympanic cavity) testifies to the ability of the endoscopic technique to identify and eradicate disease within this space and its extensions, including the facial recess, sinus tympani, and hypotympanum. There are 2 distinct areas of clear advantage for the endoscope which could be incorporated immediately into any practice. First is office-based evaluation of patients with possible cholesteatoma and retraction pockets as well as routine follow-up of cholesteatoma patients. The endoscope provides a much clearer idea regarding the extent of the disease process and damage to the ossicular chain and gives an all-encompassing picture of the tympanic membrane, ear canal, and whole retraction pocket, along with its extensions, which are usually hidden from microscopic view. Second is operative evaluation and treatment of disease within the facial recess, hypotympanum, sinus tympani, attic, and anterior part of the tympanic cavity. Ultimately, it is quite difficult to use the endoscope and microscope to perform different tasks during the same procedure, and surgeons will ultimately choose their instrument of choice based on their comfort level. I started integrating the endoscope into my middle ear surgery practice almost 8 years ago and have used it consistently in ear surgery for the past 6 years. There were few voices in the otologic community (mainly in the United States, where I have practiced for most of these years) who viewed this exercise as unnecessary and redundant. Most otologists have been supportive and have reserved their judgment until more data are available and until they gain the necessary experience and skills needed for endoscopic surgery. My enthusiasm for the endoscope in ear surgery has not waned over the years. I believe that it not only changed my technique but also changed my perception and approach to cholesteatoma from an antrum and attic disease process into a mere extension of middle ear disease that could be treated through a transcanal approach. Many
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of our teachers have ingrained in our minds that the postauricular approach is not a particularly invasive approach and that we should not hesitate to use it to gain better exposure. The wisdom of this attitude is evident to anybody who operates on the ear with the microscope and who knows how limiting the anatomy of the ear canal can be and who knows the value of good exposure to accomplish a technically adequate operation. However, most patients would view a 10-cm incision with alarm if similar results could be accomplished through a transcanal approach. Other considerations, such as the opportunity to use local anesthesia and for outpatient surgery, amplify the distinction between transcanal and postauricular approaches. CONCLUSION
The endoscopic technique allows transcanal, minimally invasive management and surveillance of cholesteatomas with long-term results that compare well to those of postauricular methods. Continuous postoperative office-based endoscopic surveillance and procedures are critical to the success of this approach. REFERENCES 1. Thomassin JM, Korchia D, Doris JMD. Endoscopic guided otosurgery in the prevention of residual cholesteatoma. Laryngoscope 1993;103:939-43. 2. Prescott R. Optical principles of endoscopy. J Med Primatol 1976;5:137-47. 3. Hawke M. Telescopic otoscopy and photography of the tympanic membrane. J Otolaryngol 1982;11:35-9. 4. Nomura Y. Effective photography in otolaryngology–head and neck surgery: endoscopic photography of the middle ear. Otolaryngol Head Neck Surg 1982;90:395-8. 5. Takahashi H, Honjo I, Fujita A. Transtympanic endoscopic findings in patients with otitis media with effusion. Arch Otolaryngol Head Neck Surg 1990;116:1186-9. 6. Poe DS, Bottrill ID. Comparison of endoscopic and surgical explorations for perilymphatic fistulas. Am J Otol 1994;15:7358. 7. McKennan KX. Endoscopic “second look” mastoidoscopy to rule out residual epitympanic/mastoid cholesteatoma. Laryngoscope 1993;103:810-4. 8. Rosenberg SI, Silverstein H, Willcox TO. Endoscopy in otology and neurotology. Am J Otol 1994;15:168-72. 9. Tarabichi M. Endoscopic middle ear surgery. Ann Otol Rhinol Laryngol 1999;108:39-46. 10. Tarabichi M. Endoscopic management of acquired cholesteatoma. Am J Otol 1997;18:5444-9. 11. Tos M. Modification of combined-approach tympanoplasty in attic cholesteatoma. Arch Otolaryngol 1982;108:772-8.
OBJECTIVES: This report evaluates long-term results of transcanal endoscopic management and surveillance of cholesteatoma. METHODS: Sixty-nine ears with acquired cholesteatoma underwent endoscopic transcanal tympanotomy and atticotomy to access and completely remove the sac. Reconstruction with a composite tragal graft was performed in 38 ears, and the cavities were packed open in 31 ears. Office-based endoscopic surveillance and follow-up were performed. RESULTS: Forty-three ears were operated on with the patient under local anesthesia, and 58 were done on an outpatient basis. Three cases were converted into postauricular tympanomastoidectomy. There were no iatrogenic facial nerve injuries. Bone thresholds were stable, except in 1 patient with perilymphatic fistula. Mean follow-up was 41 months, and 19 ears underwent 5 years of follow-up. Six ears required revision surgery, and 9 required officebased minor procedures. CONCLUSIONS: An endoscopic technique allows transcanal, minimally invasive management and surveillance of cholesteatoma with long-term results that compare well to those of postauricular methods. (Otolaryngol Head Neck Surg 2000;122: 874-81.)
T
he use of the endoscope in ear surgery has been gaining acceptance as an adjunct to traditional microscopic surgery, and many investigators have reported their experience on the subject.1-8 During the last 6 years I have relied on the endoscope as the central instrument to perform middle ear9 and cholesteatoma surgery.10 From the Division of Otolaryngology, American Hospital-Dubai. Presented at the Annual Meeting of the American Academy of Otolaryngology–Head and Neck Surgery, San Antonio, TX, September 13-16, 1998. Reprint requests: M. Tarabichi, MD, Division of Otolaryngology, American Hospital-Dubai, PO Box 5566, Dubai, United Arab Emirates. Copyright © 2000 by the American Academy of Otolaryngology– Head and Neck Surgery Foundation, Inc. 0194-5998/2000/$12.00 + 0 23/77/102111 doi:10.1067/mhn.2000.102111 874
This follow-up report discusses the long-term results with endoscopic management of acquired cholesteatoma. METHODS Instrumentation The endoscopes used were primarily 4-mm, wide-angle (20-cm-long) 0° and 30° sinuscopes. Other smaller diameter scopes were used sparingly. Video equipment included a 3-chip videocamera and monitor. All of the procedures were performed directly off the monitor and were recorded. As for instruments, initially, most picks, elevators, and curettes were modified with a 20° deflection at 1 cm from the tip of the instrument. During the past year, Otoview instruments (Smith & Nephew Richards, Memphis, TN) were used in conjunction with routine microscopic ear surgery instruments. Operating room setup was as follows. The monitor was placed on the other side of the table across the patient’s head. A Mayo stand was used to hold the camera and the scope clear from the patient’s head (most of these procedures were done with the patient under local anesthesia). An absorbent pad soaked with antifog solution was pasted on the drapes above the patient’s ear. Preoperative Evaluation Patients underwent traditional microscopic examination and audiometric studies. Also, an office-based endoscopic examination was performed. This experience extended over a few years, and initially, CT scanning of the temporal bone was used sporadically. During the past 2 years, almost all patients have undergone preoperative CT, mainly to determine the extent of disease, the possible need for a postauricular approach, and whether the patient should be offered the option of local anesthesia. Surgical Technique Patients are advised that local anesthesia with intravenous sedation is preferable but are given the option of general anesthesia. The ear canal is infiltrated with lidocaine 1% with 1/60,000 epinephrine. All surgical tasks are performed with the endoscope. A wide posterior tympanomeatal flap is elevated with the superior limb in the 1 o’clock position and the inferior limb in the 6 o’clock position. As the annulus is elevated and the middle ear is entered, the cholesteatoma sac is
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Fig 1. Endoscopic examination showing severe retraction and accumulation of cholesteatoma in the left ear.
elevated off the middle ear structures in continuity with the flap when possible. The sac is then pursued under direct vision, with the bony rim curetted or drilled just enough to continue the dissection process under direct vision. The drilling is usually done either with a microdrill system (Skeeter drill; Xomed-Treace, Jacksonville, FL) or with different sized bone curettes under continuous monitoring with the endoscope. The surgical field is irrigated frequently, and all drilling and curetting are confined to the area superior to an imaginary line that runs over the horizontal segment of the facial nerve and extends posteriorly into the ear canal. The body of the incus and the head of the malleus are preserved or removed based on the extent and location of disease. Depending on the comfort level with the complete removal of cholesteatoma and the health of the middle ear mucosa, the decision is made whether to delay ossicular reconstruction and plan a second-look operation; otherwise, appropriate ossicular chain work is performed, and the attic defect is closed with a composite tragal graft. If the sac extends beyond the attic, aggressive bone removal is carried out to provide open endoscopic access into the attic and all the way posteriorly into the antrum. All squamous epithelium is removed, and the attic and antral defect are packed open. Tympanic membrane defects inferior to the horizontal segment of the facial nerve (including atelectatic areas) are reconstructed with a composite tragal graft, which is placed directly on, and up to, the horizontal segment of the facial nerve superiorly and on a bed of Gelfoam that is packed in the middle ear inferiorly. The
ear canal, along with the open attic, is then packed with Gelfoam. Continuous office-based endoscopic examination and follow-up are performed. Patients who have extensive disease where the antrum and the attic are packed open undergo routine cleaning of the cavities with continuous surveillance for recurrent cholesteatoma and any significant narrowing of the neck of cavity. Office-based procedures include limited curetting of bone and removal of soft tissue, which are performed as needed. The hospital’s ethics committee approved this study, and informed consent was obtained from patients. RESULTS
All patients had severe retraction with bony erosion, and complete removal of dermal debris could not be accomplished under the microscope. None of the patients had previous ear surgery on the involved ear. Endoscopic office-based examination was incorporated into all routine office evaluations and follow-ups. Sixty-nine ears had acquired cholesteatoma and underwent endoscopic transcanal tympanotomy with extended atticotomy to access and completely excise the cholesteatoma sac. Forty-three procedures were performed with the patient under general anesthesia, and 58 procedures were done on an outpatient basis. None of the patients had previous surgery in the involved ear. Three procedures were converted intraoperatively into traditional postauricular tympanomastoidectomy after an initial endoscopic approach. There were 2 distinct groups of patients.
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Fig 2. Tympanomeatal flap is elevated and middle ear is entered (A). Cholesteatoma sac is identified over the posterosuperior part of the tympanic cavity extending into the antrum and mastoid cavity.
Group 1 included 38 patients with endoscopically accessible disease in which the sac could be easily elevated off the ossicles, middle ear, and attic. The decision to proceed with any needed ossiculoplasty was based on the degree of certainty of the complete removal of disease and the health of the middle ear mucosa. Residual attic and tympanic membrane defects were reconstructed with a composite tragal graft. Group 2 included 31 patients with extensive disease within the mastoid cavity proper. Wide transcanal atticotomy was performed, and the bony defect was enlarged into the antrum and was packed and left open. Residual tympanic membrane defects inferior to the horizontal segment of the facial nerve were reconstructed with composite tragal graft in 9 patients. The tympanic cavity was packed with Gelfoam inferior to the horizontal segment of the facial nerve, and the graft was positioned on top of the Gelfoam inferiorly and immediately on top of the facial nerve and medial wall of the attic superiorly. There were no untoward intraoperative events. The size of the ear canal was not a limiting factor. None of the patients had worsening of sensorineural hearing loss (defined as > 10 dB change in bone conduction thresholds at 500, 1000, 2000, or 3000 Hz), except for 1 patient who had a 15-dB worsening of bone conduction at 3000 Hz. This particular patient had severe sensorineural hearing loss and dizziness that lasted for 1
week before initial evaluation. This patient did have a lateral semicircular canal fistula. There were no incidents of iatrogenic facial nerve injuries in this series. Mean follow-up was 41 months, with 19 ears observed for 5 years. Six ears required revision surgery, with 4 patients undergoing revision endoscopic procedures to convert into an open attic and antrum cavity and 2 patients undergoing classic canal wall down postauricular procedures. All recurrences were mastoid, attic, and antrum recurrences, and there was only 1 case of tympanic cavity disease, which manifested as a small incidental pearl attached to the underlayer of the tympanic membrane. Only 1 operating room– based revision procedure occurred in group B. Nine ears in group B required office-based minor procedures, which included removal of some disease from the open attic, minimal curetting of bony regrowth to open up the closed antrum and attic, and incision of scarred skin and soft tissue (limiting access to the cavity) and deflecting the edges into the underlying open bony cavity. Narrowing of the neck of the cavity was observed only during the first 8 months after surgery, and all 9 office-based procedures were performed during that period of time. There was only 1 case in which the open attic was closed significantly and the ear continued draining. This was addressed with postauricular canal wall down mastoidectomy. All other patients had healthy-looking shallow cavities. There were 19 ears with 5 years’ follow-up
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Fig 3. Sac was removed off the medial wall of the tympanic cavity (oval window, A; facial nerve, B). Sac remnant (C) is left over the lateral semicircular canal.
after an endoscopic approach for removal of a cholesteatoma. Only 2 cases needed operating room–based revision surgery in this group, and this actually occurred during the first 2 years after surgery. In this group of patients, there were 9 cases in which the attic was packed open at the time of surgery, and the residual cavities proved to be shallow, benign, and problem-free areas. CASE REPORT A 52-year-old man had a 1-week history of severe dizziness and hearing loss. He reported a previous history of ear problems but no ear surgery. An audiogram revealed severe sensorineural hearing loss on the left side. Fistula test results were negative. Endoscopic examination of the left ear showed severe retraction of the tympanic membrane and cholesteatoma (Fig 1). With the patient under local anesthesia, a wide tympanomeatal flap was elevated, and a large cholesteatoma sac was identified (Fig 2). The sac was elevated off the middle ear cavity, the medial wall of the middle ear and the round and oval windows were inspected for fistulas, and a remnant of the sac was left over the lateral semicircular canal (Fig 3). The area of the lateral semicircular canal was palpated, and then the sac was carefully removed. A small lateral canal fistula was identified (Fig 4). A graft was positioned over the area, and a composite tragal graft was used to reconstruct the upper part of the tympanic membrane (Fig 5). The attic was packed open. Follow-up examination at 33 years showed a healthy attic and antrum, and the patient did not report any major dizziness symptoms (Fig 6).
DISCUSSION
The introduction of the binocular operating microscope was a landmark event in the development of modern otology, and it clearly changed the scope and character of ear surgery. Despite continuous technical improvements, the basic optical principles, and their limitations, have stayed the same for the last 3 decades. With the introduction of the endoscope into other branches of surgery, there have been attempts to use it in otology. The diagnostic, mostly photographic, role of the endoscope for examining the tympanic membrane and the ear canal has been widely publicized.3 Transtympanic middle ear endoscopy was initially reported by Nomura4 and Takahashi et al.5 Poe and Bottrill6 described transtympanic endoscopy for the confirmation of perilymphatic fistula as well as the identification of other middle ear pathology. McKennan7 described second-look endoscopic inspection of mastoid cavities through a small postauricular incision. Thomassin and Korchia1 reported operative ear endoscopy for mastoid cavities and designed an instrument set to be used in these settings. Other investigators looked at the role of the endoscope in neurotologic procedures.8 Safety Concerns with Endoscopic Ear Surgery Excessive heat dissipation. This was evident only when a xenon light source was used. Adequate illumination of the middle ear space can be accomplished
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Fig 4. Sac is completely removed and lateral canal fistula (E), oval window (G), and facial nerve (D) are identified.
with lower settings on the regular light source (because of the size of the cavity) without the need for xenon systems. Also, the tip of the endoscope requires continuous cleaning with an antifog solution, which probably helps in cooling the endoscope.
wide-angle 0° endoscopes provide excellent visualization of structures such as the ear canal.
Accidental patient movement with secondary direct trauma by the tip of the endoscope. The rel-
sible even when using the 0° endoscope because of the wide angle view of the more recent endoscopes.
atively large diameter of the endoscope used (4 mm) and the anatomy of the ear canal and middle ear space will usually preclude the introduction of the endoscope beyond the tympanic ring. Even in endoscopic stapedectomy, there is less need for curetting the posterior and superior aspects of the canal for exposure; this provides a protective rim that prevents the advancement of the endoscope beyond the tympanic ring.
Ability to visualize past the shaft of larger surgical instruments such as drills and curettes. It is not
Visualization of hidden structures such as an anterior tympanic membrane perforation, sinus tympani, facial recess, attic, and hypotympanum. This is pos-
uncommon in microscopic surgery for the handle of the instrument to prevent visualization of the operative field (after the initial positioning and engagement) and for the surgeon to rely on the feel of the instrument rather than the continuous visualization of the operative field. Disadvantages of Endoscopes
Advantages of Endoscopes Wide angle of view. The endoscopic view usually
includes the whole tympanic ring and ear canal at the same time. In contrast, the field of the microscope is defined by the narrowest segment in the ear canal, therefore requiring continuous manipulation of the microscope and/or the patient’s head. Better visualization of structures that are parallel to the axis of the microscope. It is usually necessary
to position structures at a right angle to the axis of the microscope for adequate visualization, which is difficult or impossible in certain situations. The 30° and the
Loss of depth perception and binocular vision.
This is easily compensated for with experience. In operative endoscopy, the introduction of the instrument into the field and the way it is visualized on the monitor provide tactile and visual cues that are used by the experienced endoscopist to reconstruct a 3-dimensional view of the operative site. Even though newer endoscopes might provide depth perception, this issue is more related to the experience of the surgeon than to the limitations of present day technology. One-handed surgical technique. This is probably the most important issue to deal with in endoscopic ear
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Fig 5. Tragal composite graft (L) is used to reconstruct the upper part of the tympanic membrane over a bed of Gelfoam (E), and the attic and antrum are packed open after the fistula is covered with a fascial graft (not shown).
surgery. Meticulous attention to hemostasis is essential and is easier given the excellent visualization of the ear canal and the ability to cauterize bleeding points along the edges of the incised skin in the canal, the most common site of bleeding in middle ear procedures. With experience, the tip of the endoscope can be used to push or lift certain structures. Further development of endoscopic ear surgery might be enhanced by incorporating other functions into the endoscope. Physician training. Although there is a definite learning curve, acquiring the necessary skills should not be too difficult for the experienced nasal endoscopist. It might be rather hard for established otologists who lack endoscopic training to make the necessary transition. Cost of equipment. Most of the equipment used is available in most operating rooms. The only extra instruments involve very minor modifications of the existing instruments. Fogging and smearing of the tip of the endoscope. This can be handled very easily by rubbing the
tip against the antifog pad that is pasted close to the ear. The fact that the endoscope is used in close contact to the surgical field (to obtain magnification) has never interfered with the surgical task being performed. The surgical management of cholesteatoma has been designed around the advantages and limitations of the surgical microscope, with postauricular exposure as a
critical direct line access into the advancing sac as it reaches the antrum and mastoid cavity. The wide-angle view of the endoscope transforms the surgeon’s perception of the advancing cholesteatoma sac into a mere extension of middle ear and attic disease, with the ability to pursue the sac and remove it through a transcanal approach. The endoscope provides an excellent means of evaluating the middle ear space along with its hard to visualize extensions, including the sinus tympani, facial recess, sinus tympani, and hypotympanum. This represents a clear advantage over the microscopic technique and could be complementary to it when evaluating and treating cholesteatoma with the traditional and timehonored postauricular approach. For most patients the endoscopic technique transformed the ultimate surgical approach and allowed the surgeon to think of the disease process as a retraction pocket rather than a developing cholesteatoma; also, it enabled the surgeon to eradicate disease, reconstruct the sound-conduction mechanism, and close any residual bony or tympanic membrane defect. Thirty-one patients had extensive disease involving the antrum, which was pursued and grossly eradicated. Definitive treatment was accomplished by leaving the attic and mastoid cavity open to the ear canal superiorly and posteriorly while reconstructing the tympanic membrane up to the level of the horizontal segment of the facial nerve with the graft
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Fig 6. Endoscopic examination of the left ear 3 years after surgery showing a manageable and clean cavity.
resting against Gelfoam inferiorly and immediately on top of the medial wall of the attic and facial nerve superiorly. The rationale for the surgical approach in these patients is based on the good results reported by Tos in 1982, when he proposed a different approach to attic cholesteatoma, which he summarized as follows: Since 1970 I have applied my own modification of CAT (Combined-Approach Tympanoplasty) that is based on other surgical principles than the classic CAT and on a new philosophy, i.e., to create such conditions in the attic that the retraction does not necessarily lead to recurrent cholesteatoma requiring reoperation, but most often to a peaceful small cavity with an acceptably wide access. Furthermore, any residual cholesteatoma can be observed through the atticotomy opening, replacing a second look operation.”11
The endoscope offers a better opportunity to accomplish these objectives through a transcanal approach. Given the wide angle of view of the endoscope, it is not necessary to take down the whole posterior wall to maintain the mastoid cavity. These cavities could easily be maintained and inspected with the endoscope in the office, like the open mastoid cavity after canal wall down procedures. It is my experience that such a limited cavity has proved to be manageable and benign and does not require continuous cleaning.
The average operating time was shorter than with the traditional postauricular approach. This could be easily explained by the fact that the pathology is accessed directly through the canal without the need to drill a large cavity as in postauricular mastoidectomy. Good transcanal endoscopic access into the attic and antrum could be provided by removal of a rather limited amount of bone, mostly with a curette or microdrill. The safety of the facial nerve is ensured by the direct identification of the horizontal segment of the facial nerve and by limiting any drilling in the posterior canal to the area superior that. The facial recess is easily explored with the endoscope through a transcanal approach without any drilling or manipulation close to the facial nerve. I have observed 19 ears for 5 years after an endoscopic approach for removal of cholesteatoma and have found only 2 cases in which there was a need for revision surgery in this group, and this actually occurred during the first 2 years after surgery. In this group of patients, there were 9 cases in which the attic was packed open, and the residual cavities proved to be shallow, benign, and problem-free areas. An essential part of the management is continuous outpatient endoscopic follow-up and examination of these cavities; if the neck of the cavity is closing, office-based debridement and curetting should be done to prevent closure. This nar-
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rowing in the neck of the cavity usually occurs during the first year, and if adequately managed, will subside and improve during the following years. Given the ultimate shallowness of these cavities and their benign course, I have been more inclined to leave the attic open rather than reconstruct the attic defect. The lack of any recurrence in the tympanic cavity (only 1 case had a small pearl in the tympanic cavity) testifies to the ability of the endoscopic technique to identify and eradicate disease within this space and its extensions, including the facial recess, sinus tympani, and hypotympanum. There are 2 distinct areas of clear advantage for the endoscope which could be incorporated immediately into any practice. First is office-based evaluation of patients with possible cholesteatoma and retraction pockets as well as routine follow-up of cholesteatoma patients. The endoscope provides a much clearer idea regarding the extent of the disease process and damage to the ossicular chain and gives an all-encompassing picture of the tympanic membrane, ear canal, and whole retraction pocket, along with its extensions, which are usually hidden from microscopic view. Second is operative evaluation and treatment of disease within the facial recess, hypotympanum, sinus tympani, attic, and anterior part of the tympanic cavity. Ultimately, it is quite difficult to use the endoscope and microscope to perform different tasks during the same procedure, and surgeons will ultimately choose their instrument of choice based on their comfort level. I started integrating the endoscope into my middle ear surgery practice almost 8 years ago and have used it consistently in ear surgery for the past 6 years. There were few voices in the otologic community (mainly in the United States, where I have practiced for most of these years) who viewed this exercise as unnecessary and redundant. Most otologists have been supportive and have reserved their judgment until more data are available and until they gain the necessary experience and skills needed for endoscopic surgery. My enthusiasm for the endoscope in ear surgery has not waned over the years. I believe that it not only changed my technique but also changed my perception and approach to cholesteatoma from an antrum and attic disease process into a mere extension of middle ear disease that could be treated through a transcanal approach. Many
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of our teachers have ingrained in our minds that the postauricular approach is not a particularly invasive approach and that we should not hesitate to use it to gain better exposure. The wisdom of this attitude is evident to anybody who operates on the ear with the microscope and who knows how limiting the anatomy of the ear canal can be and who knows the value of good exposure to accomplish a technically adequate operation. However, most patients would view a 10-cm incision with alarm if similar results could be accomplished through a transcanal approach. Other considerations, such as the opportunity to use local anesthesia and for outpatient surgery, amplify the distinction between transcanal and postauricular approaches. CONCLUSION
The endoscopic technique allows transcanal, minimally invasive management and surveillance of cholesteatomas with long-term results that compare well to those of postauricular methods. Continuous postoperative office-based endoscopic surveillance and procedures are critical to the success of this approach. REFERENCES 1. Thomassin JM, Korchia D, Doris JMD. Endoscopic guided otosurgery in the prevention of residual cholesteatoma. Laryngoscope 1993;103:939-43. 2. Prescott R. Optical principles of endoscopy. J Med Primatol 1976;5:137-47. 3. Hawke M. Telescopic otoscopy and photography of the tympanic membrane. J Otolaryngol 1982;11:35-9. 4. Nomura Y. Effective photography in otolaryngology–head and neck surgery: endoscopic photography of the middle ear. Otolaryngol Head Neck Surg 1982;90:395-8. 5. Takahashi H, Honjo I, Fujita A. Transtympanic endoscopic findings in patients with otitis media with effusion. Arch Otolaryngol Head Neck Surg 1990;116:1186-9. 6. Poe DS, Bottrill ID. Comparison of endoscopic and surgical explorations for perilymphatic fistulas. Am J Otol 1994;15:7358. 7. McKennan KX. Endoscopic “second look” mastoidoscopy to rule out residual epitympanic/mastoid cholesteatoma. Laryngoscope 1993;103:810-4. 8. Rosenberg SI, Silverstein H, Willcox TO. Endoscopy in otology and neurotology. Am J Otol 1994;15:168-72. 9. Tarabichi M. Endoscopic middle ear surgery. Ann Otol Rhinol Laryngol 1999;108:39-46. 10. Tarabichi M. Endoscopic management of acquired cholesteatoma. Am J Otol 1997;18:5444-9. 11. Tos M. Modification of combined-approach tympanoplasty in attic cholesteatoma. Arch Otolaryngol 1982;108:772-8.