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Laser-assisted tympanoplasty for preservation of the ossicular chain in cholesteatoma
Laser-Assisted Tympanoplasty for Preservation of the Ossicular Chain in Cholesteatoma Kazunori Nishizaki, MD, Koji Yuen, MD, Teruhiro Ogawa, MD, Shigenobu Nomiya, MD, Mitsuhiro Okano, MD, and Kunihiro Fukushima, MD We report the use of potassium titanyl phosphate laser-assisted tympanoplasty in amputations of the malleus and incus in 2 patients with cholesteatoma medial to those ossicles that had not destroyed the ossicular chain continuity. In both cases, the laser successfully removed portions of the ossicles to allow removal of the cholesteatoma; importantly, the laser preserved certain ossicular ligaments, thus keeping the ossicular chain continuous. Postoperatively, both patients showed satisfactory hearing. Although the prevalence of cholesteatoma medial to the ossicles with maintained ossicular continuity is limited, the laser-assisted procedure described here is useful for maintaining hearing ability in these cases. (Am J Otolaryngol 2001;22:424-427. Copyright © 2001 by W.B. Saunders Company)
When performing tympanoplasty for cholesteatoma treatment, removal of the disease is of the utmost importance, with consideration for hearing function. If the cholesteatoma does not destroy the ossicular chain, hearing impairment is often minimal. However, removing cholesteatoma medial to the ossicles presents a special problem. For such cases, generally the malleus and/or incus are removed, and then ossiculoplasty using a columella is performed. For some, hearing restoration does not occur. Tos1 stated that his policy for middle ear surgery for chronic otitis with cholesteatoma is to consistently keep the ossicular chain intact. If the ossicular continuity is maintained, hearing deterioration should be prevented. Here we report treatment of two patients with cholesteatoma medial to the ossicles, using laser-assisted tympanoplasty. This procedure maintained the ossicular chain, and postoperative hearing function was maintained or improved.
postulated that, if the anterior mallear ligament and either the superior mallear ligament or the posterior incudal ligament were preserved, the ossicular chain could work normally. Given this hypothesis, we performed the following operative procedures under general anesthesia. Without damaging the ossicular ligaments, the incus alone or the incus and malleus were amputated using a potassium titanyl phosphate (KTP) laser. This technique preserved the ossicular chain continuity. Specifically, bone tissue was vaporized with the laser using a spot size of 0.4 mm with a power setting of 4 to 5 Watts for 0.2 seconds in pulse mode. Vaporized bone formed char, which was resected carefully by a pick and middle ear scissors, so as not to damage inner ear function. After amputation of the ossicles, the cholesteatoma was resected easily under a wider field of operation. During this procedure, 4 mg of dexamethasone was administered prophylactically.
SURGICAL TECHNIQUE From our experience of cholesteatoma surgery in cases like that shown in Figure 1, we From the Department of Otolaryngology, Okayama University Medical School, Okayama, Japan. Address reprint requests to Nishizaki Kazunori, MD, Department of Otolaryngology, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan. Copyright © 2001 by W.B. Saunders Company 0196-0709/01/2206-0011$35.00/0 doi:10.1053/ajot.2001.28081 424
CASE REPORTS Case 1 A 42-year-old man who complained of left otalgia and left ear hearing loss since the age of 40 was referred to our department. A large aural polyp originating from the pars flaccida was discovered; this polyp covered the superior half of the tympanic membrane and the remaining tympanic membrane was an amber
American Journal of Otolaryngology, Vol 22, No 6 (November-December), 2001: pp 424-427
LASER-ASSISTED TYMPANOPLASTY
425
3). A CT scan showed a diffuse shadow from the attic to the mastoid. The patient was diagnosed as having cholesteatoma. Intraoperative findings showed cholesteatoma invading from the attic to the mastoid. Cholesteatoma medial to the incus was accessed and resected after amputating the posterior half of the incus body by using the KTP laser. The posterior incudal ligament was resected, whereas the anterior and superior mallear ligaments were preserved. A postoperative audiogram closed
Fig 1. In this case, both the posterior part of the incus body (I) and the posterior incudal ligament were destroyed by cholesteatoma, but the ossicular chain was continuous. Chorda tympani (C), Horizontal facial canal (F).
color. Staphylococcus simulans was detected in aural discharge. A pure tone audiogram showed an approximately 30 dB conductive hearing loss on the left side (Fig. 2). A computed tomography (CT) scan showed a diffuse shadow from the tympanic cavity to the mastoid. From these findings, cholesteatoma was strongly suspected. Intraoperative findings showed cholesteatoma invading from the attic to the mastoid. Cholesteatoma medial to the malleus and incus was accessed and resected after amputating the superior halves of the malleus head and incus body with the KTP laser. The superior mallear ligament was resected, while the anterior mallear ligament and the posterior incudal ligament were preserved. A postoperative audiogram closed the air-bone gap (Fig 2), and postoperative endoscopy showed the amputated malleus and incus as well as the air-fluid line in the tympanic cavity (Fig 2). Case 2 A 21-year-old man who had left aural discharge for a year and left ear hearing loss since childhood was referred to our department. Bone erosion with granulation was present in the attic, and debris from there was aspirated. Methicillin-sensitive Staphylococcus aureus was detected in aural discharge. A pure tone audiogram found an approximately 15 dB conductive hearing loss on the left side (Fig
Fig 2. Case 1 (A) An audiogram shows the preoperative hearing function (measured October 13, 1998) with a solid line and the postoperative hearing function (measured March 3, 2000) with a dotted line. An airbone gap by secretory otitis media was still present postoperatively. (B) Postoperative endoscopic findings show the amputated malleus (M) (superior half of the head is missing) and the amputated incus (I) (superior half of the body is missing) through the tympanic membrane. Air-fluid lines (arrows) are also apparent.
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laser to amputate the ossicles while preserving ossicular chain continuity in 2 cases of cholesteatoma. The malleus and incus have 4 ligaments: the anterior, superior, lateral mallear ligaments, and the posterior incudal ligament. We devised 2 procedures that allowed ossicle amputation while leaving certain ligaments intact (Fig 4). In both cases reported here, the anterior mallear ligament was always preserved. In addition, the posterior incudal ligament was preserved in Case 1 and the superior mallear ligament was preserved in Case 2. This procedure maintained ossicular chain continuity, and postoperative hearing function was preserved in both cases. Facial palsy and inner ear damage are potential complications of laser stapes surgery.4,5 In cases of cholesteatoma medial to the ossicles, however, the cholesteatoma itself prevents laser damage to the facial nerve and inner ear function. Bone necrosis of the ossicles may eventually occur, although excess bone loss was not found postoperatively. Moreover, by preserving the ossicular ligaments, the vessels supplying the ossicles also remain intact. This condition may prevent postoperative necrosis of the ossicles.
Fig 3. Case 2 (A) An audiogram shows the preoperative hearing function (measured February 2, 2000) with a solid line and the postoperative hearing function (measured July 17, 2000) with a dotted line. (B) Postoperative endoscopic findings show the amputated incus body (I) (missing its posterior half) through the tympanic membrane.
the air-bone gap (Fig 3), and postoperative endoscopy showed the amputated incus (Fig 3). DISCUSSION Although most procedures in chronic ear surgery can be performed without use of a laser,2 laser techniques offer the advantage of minimizing vibration trauma to the inner ear, especially when manipulating lesions near the ossicles.3 Given this advantage, we used a
Fig 4. Illustration of the lines used to guide ossicle amputation in the procedure described here. Line 1 is for amputating the superior halves of the malleus head and incus body. The anterior mallear ligament and inferior incudal ligament are preserved. Line 2 is for amputating the posterior half of the incus body. The anterior and superior mallear ligaments are preserved.
LASER-ASSISTED TYMPANOPLASTY
A disadvantage of using a KTP laser in this procedure is that it is extremely time-consuming; 30 minutes was often required to amputate the ossicles. Recently Er:YAG (erbium yttrium aluminum garnet) lasers have been reported to be more appropriate for amputating the ossicles because of their explosive vaporization.6,7 Currently, the surgical outcomes and the frequency of complications are similar between the different laser systems.5,8,9 However, the invention of new laser systems may eventually extend the possibilities of laser surgery for the treatment of chronic middle ear disease in the future. CONCLUSION Although patients with cholesteatoma medial to the ossicles that does not destroy ossicular continuity account for a small portion of all cases of cholesteatoma, the laser-assisted procedure described here is useful for
427
potentially maintaining the hearing function of such patients. REFERENCES 1. Tos M: Manual of Middle Ear Surgery (vol 3) Stuttgart, Germany, Thieme, 1997 2. McGee TM: Laser applications in ossicular surgery. Otolaryngol Clin North Am 23:7-18, 1990 3. Thedinger BS: Applications of the KTP laser in chronic ear surgery. Am J Otol 11:79-84, 1990 4. Saeed SR, Jackler RK: Laser in surgery for chronic ear disease. Otolaryngol Clin N Am 29:245-255, 1996 5. Vernick DM: Laser applications in ossicular surgery. Otolaryngol Clin N Am 29:931-941, 1996 6. Nagel D: The Er:YAG laser in ear surgery: First clinical results. Laser Surg Med 21:79-87, 1997 7. Lenarz T, Heermann R, Kemph H-G: Erbium YAG laser in middle ear surgery, in Huttenbrick K-B (ed): Middle Ear Mechanics in Research and Otology. Proceedings of the internal workshop on middle ear mechanics in research and otosurgery, Dresden, Germany, 1996 8. Lesinski SG, Palmer A: Lasers for otosclerosis: CO2 vs. Argon and KTP-532. Laryngoscope. 99:1-8, 1989 (suppl 46) 9. Vernick DM: A comparison of the results of KTP and CO2 laser stapedotomy. Am J Otol 17:221-224, 1996
When performing tympanoplasty for cholesteatoma treatment, removal of the disease is of the utmost importance, with consideration for hearing function. If the cholesteatoma does not destroy the ossicular chain, hearing impairment is often minimal. However, removing cholesteatoma medial to the ossicles presents a special problem. For such cases, generally the malleus and/or incus are removed, and then ossiculoplasty using a columella is performed. For some, hearing restoration does not occur. Tos1 stated that his policy for middle ear surgery for chronic otitis with cholesteatoma is to consistently keep the ossicular chain intact. If the ossicular continuity is maintained, hearing deterioration should be prevented. Here we report treatment of two patients with cholesteatoma medial to the ossicles, using laser-assisted tympanoplasty. This procedure maintained the ossicular chain, and postoperative hearing function was maintained or improved.
postulated that, if the anterior mallear ligament and either the superior mallear ligament or the posterior incudal ligament were preserved, the ossicular chain could work normally. Given this hypothesis, we performed the following operative procedures under general anesthesia. Without damaging the ossicular ligaments, the incus alone or the incus and malleus were amputated using a potassium titanyl phosphate (KTP) laser. This technique preserved the ossicular chain continuity. Specifically, bone tissue was vaporized with the laser using a spot size of 0.4 mm with a power setting of 4 to 5 Watts for 0.2 seconds in pulse mode. Vaporized bone formed char, which was resected carefully by a pick and middle ear scissors, so as not to damage inner ear function. After amputation of the ossicles, the cholesteatoma was resected easily under a wider field of operation. During this procedure, 4 mg of dexamethasone was administered prophylactically.
SURGICAL TECHNIQUE From our experience of cholesteatoma surgery in cases like that shown in Figure 1, we From the Department of Otolaryngology, Okayama University Medical School, Okayama, Japan. Address reprint requests to Nishizaki Kazunori, MD, Department of Otolaryngology, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan. Copyright © 2001 by W.B. Saunders Company 0196-0709/01/2206-0011$35.00/0 doi:10.1053/ajot.2001.28081 424
CASE REPORTS Case 1 A 42-year-old man who complained of left otalgia and left ear hearing loss since the age of 40 was referred to our department. A large aural polyp originating from the pars flaccida was discovered; this polyp covered the superior half of the tympanic membrane and the remaining tympanic membrane was an amber
American Journal of Otolaryngology, Vol 22, No 6 (November-December), 2001: pp 424-427
LASER-ASSISTED TYMPANOPLASTY
425
3). A CT scan showed a diffuse shadow from the attic to the mastoid. The patient was diagnosed as having cholesteatoma. Intraoperative findings showed cholesteatoma invading from the attic to the mastoid. Cholesteatoma medial to the incus was accessed and resected after amputating the posterior half of the incus body by using the KTP laser. The posterior incudal ligament was resected, whereas the anterior and superior mallear ligaments were preserved. A postoperative audiogram closed
Fig 1. In this case, both the posterior part of the incus body (I) and the posterior incudal ligament were destroyed by cholesteatoma, but the ossicular chain was continuous. Chorda tympani (C), Horizontal facial canal (F).
color. Staphylococcus simulans was detected in aural discharge. A pure tone audiogram showed an approximately 30 dB conductive hearing loss on the left side (Fig. 2). A computed tomography (CT) scan showed a diffuse shadow from the tympanic cavity to the mastoid. From these findings, cholesteatoma was strongly suspected. Intraoperative findings showed cholesteatoma invading from the attic to the mastoid. Cholesteatoma medial to the malleus and incus was accessed and resected after amputating the superior halves of the malleus head and incus body with the KTP laser. The superior mallear ligament was resected, while the anterior mallear ligament and the posterior incudal ligament were preserved. A postoperative audiogram closed the air-bone gap (Fig 2), and postoperative endoscopy showed the amputated malleus and incus as well as the air-fluid line in the tympanic cavity (Fig 2). Case 2 A 21-year-old man who had left aural discharge for a year and left ear hearing loss since childhood was referred to our department. Bone erosion with granulation was present in the attic, and debris from there was aspirated. Methicillin-sensitive Staphylococcus aureus was detected in aural discharge. A pure tone audiogram found an approximately 15 dB conductive hearing loss on the left side (Fig
Fig 2. Case 1 (A) An audiogram shows the preoperative hearing function (measured October 13, 1998) with a solid line and the postoperative hearing function (measured March 3, 2000) with a dotted line. An airbone gap by secretory otitis media was still present postoperatively. (B) Postoperative endoscopic findings show the amputated malleus (M) (superior half of the head is missing) and the amputated incus (I) (superior half of the body is missing) through the tympanic membrane. Air-fluid lines (arrows) are also apparent.
426
NISHIZAKI ET AL
laser to amputate the ossicles while preserving ossicular chain continuity in 2 cases of cholesteatoma. The malleus and incus have 4 ligaments: the anterior, superior, lateral mallear ligaments, and the posterior incudal ligament. We devised 2 procedures that allowed ossicle amputation while leaving certain ligaments intact (Fig 4). In both cases reported here, the anterior mallear ligament was always preserved. In addition, the posterior incudal ligament was preserved in Case 1 and the superior mallear ligament was preserved in Case 2. This procedure maintained ossicular chain continuity, and postoperative hearing function was preserved in both cases. Facial palsy and inner ear damage are potential complications of laser stapes surgery.4,5 In cases of cholesteatoma medial to the ossicles, however, the cholesteatoma itself prevents laser damage to the facial nerve and inner ear function. Bone necrosis of the ossicles may eventually occur, although excess bone loss was not found postoperatively. Moreover, by preserving the ossicular ligaments, the vessels supplying the ossicles also remain intact. This condition may prevent postoperative necrosis of the ossicles.
Fig 3. Case 2 (A) An audiogram shows the preoperative hearing function (measured February 2, 2000) with a solid line and the postoperative hearing function (measured July 17, 2000) with a dotted line. (B) Postoperative endoscopic findings show the amputated incus body (I) (missing its posterior half) through the tympanic membrane.
the air-bone gap (Fig 3), and postoperative endoscopy showed the amputated incus (Fig 3). DISCUSSION Although most procedures in chronic ear surgery can be performed without use of a laser,2 laser techniques offer the advantage of minimizing vibration trauma to the inner ear, especially when manipulating lesions near the ossicles.3 Given this advantage, we used a
Fig 4. Illustration of the lines used to guide ossicle amputation in the procedure described here. Line 1 is for amputating the superior halves of the malleus head and incus body. The anterior mallear ligament and inferior incudal ligament are preserved. Line 2 is for amputating the posterior half of the incus body. The anterior and superior mallear ligaments are preserved.
LASER-ASSISTED TYMPANOPLASTY
A disadvantage of using a KTP laser in this procedure is that it is extremely time-consuming; 30 minutes was often required to amputate the ossicles. Recently Er:YAG (erbium yttrium aluminum garnet) lasers have been reported to be more appropriate for amputating the ossicles because of their explosive vaporization.6,7 Currently, the surgical outcomes and the frequency of complications are similar between the different laser systems.5,8,9 However, the invention of new laser systems may eventually extend the possibilities of laser surgery for the treatment of chronic middle ear disease in the future. CONCLUSION Although patients with cholesteatoma medial to the ossicles that does not destroy ossicular continuity account for a small portion of all cases of cholesteatoma, the laser-assisted procedure described here is useful for
427
potentially maintaining the hearing function of such patients. REFERENCES 1. Tos M: Manual of Middle Ear Surgery (vol 3) Stuttgart, Germany, Thieme, 1997 2. McGee TM: Laser applications in ossicular surgery. Otolaryngol Clin North Am 23:7-18, 1990 3. Thedinger BS: Applications of the KTP laser in chronic ear surgery. Am J Otol 11:79-84, 1990 4. Saeed SR, Jackler RK: Laser in surgery for chronic ear disease. Otolaryngol Clin N Am 29:245-255, 1996 5. Vernick DM: Laser applications in ossicular surgery. Otolaryngol Clin N Am 29:931-941, 1996 6. Nagel D: The Er:YAG laser in ear surgery: First clinical results. Laser Surg Med 21:79-87, 1997 7. Lenarz T, Heermann R, Kemph H-G: Erbium YAG laser in middle ear surgery, in Huttenbrick K-B (ed): Middle Ear Mechanics in Research and Otology. Proceedings of the internal workshop on middle ear mechanics in research and otosurgery, Dresden, Germany, 1996 8. Lesinski SG, Palmer A: Lasers for otosclerosis: CO2 vs. Argon and KTP-532. Laryngoscope. 99:1-8, 1989 (suppl 46) 9. Vernick DM: A comparison of the results of KTP and CO2 laser stapedotomy. Am J Otol 17:221-224, 1996