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Efficacy of mastoidectomy on MRSA-infected chronic otitis media with tympanic membrane perforation
Auris Nasus Larynx 34 (2007) 9–13 www.elsevier.com/locate/anl
Efficacy of mastoidectomy on MRSA-infected chronic otitis media with tympanic membrane perforation§ Toshihiko Mutoh *, Osamu Adachi, Kojiro Tsuji, Mieko Okunaka, Masafumi Sakagami Department of Otolaryngology, Hyogo College of Medicine, 1-1 Mukogawa, Nishinomiya City, Hyogo 663-8501, Japan Received 10 February 2006; accepted 26 May 2006 Available online 21 August 2006
Abstract Objectives: To retrospectively evaluate the efficacy of mastoidectomy on methicillin-resistant Staphylococcus aureus (MRSA)-infected chronic otitis media in comparison with methicillin-susceptible Staphylococcus aureus (MSSA)-infected otitis media. Methods: Between January 1998 and October 2003, 18 ears underwent surgery for MRSA-infected chronic otitis media with tympanic membrane perforation at the Department of Otolaryngology, Hyogo College of Medicine. Another 33 ears underwent surgery for MSSAinfected chronic otitis media with tympanic membrane perforation during the same period. The postoperative results of graft success rate, hearing results and other complications were compared between MRSA-infected and MSSA-infected ears with or without mastoidectomy, and discharging or dry ears. Results: In MRSA, the mastoidectomy group tended to have a better graft success rate than the non-mastoidectomy group. In MSSA, there were almost the same graft success rate and hearing results between the mastoidectomy and non-mastoidectomy groups regardless of the presence of discharge. In MRSA-infected discharging ears, the rate of postoperative complications (ear drum perforation, persistent otorrhea, and dehiscence of skin incision) were significantly lower in the mastoidectomy group than in the non-mastoidectomy group ( p = 0.046). Conclusion: Mastoidectomy had significantly better results concerning postoperative complications in discharging ears with MRSA-infected chronic otitis media. We recommend performing tympanoplasty with mastoidectomy in MRSA-infected chronic otitis media. # 2006 Elsevier Ireland Ltd. All rights reserved. Keywords: Mastoidectomy; MRSA; MSSA; Chronic otitis media; Tympanic perforation
1. Introduction Recently, hospital-acquired infection and antibiotics abuse have led to the increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in various fields in many countries [1–5]. MRSA-infected chronic otitis media has also increased [6,7]. It is difficult to eradicate bacteria from MRSA-infected chronic otitis media, and otorrhea continues in spite of antibiotic treatment for MRSA and washing out the tympanic cavity with a physiological saline solution. It remains controversial whether or not surgical therapy is necessary in MRSA§ This study was partly presented at the 105th Annual Meeting of the OtoRhino-Laryngological Society of Japan, May 13–15, 2004, Hiroshima. * Corresponding author. Tel.: +81 798 456493; fax: +81 798 418976. E-mail address: [email protected] (T. Mutoh).
infected ears. Operation for cholesteatoma with MRSA infection is an accepted course because of possible complications such as intracranial complication, labyrinthine fistula and facial palsy. On the other hand, some surgeons refuse operations for MRSA-infected otitis media with tympanic membrane perforation. It has been commonly believed that mastoidectomy is an effective procedure for the control of middle ear inflammation [8–12]. However, recent clinical studies have given rise to questions and reported that there is no significant difference in the rate of perforation closure and in hearing results between with and without mastoidectomy [13,14]. We perform tympanoplasty with mastoidectomy when otorrhea is persistent, and perform tympanoplasty without mastoidectomy when it is absent. In MRSA-infected chronic otitis media, we have also actively performed tympanoplasty after controlling otorrhea as much as possible with medical
0385-8146/$ – see front matter # 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.anl.2006.05.017
10
T. Mutoh et al. / Auris Nasus Larynx 34 (2007) 9–13
treatment. In this study, we retrospectively compared postoperative results between MRSA-infected chronic otitis media and methicillin-susceptible Staphylococcus aureus (MSSA)-infected chronic otitis media and evaluated the efficacy of mastoidectomy in MRSA-infected chronic otitis media.
2. Materials and methods Three hundred and sixteen ears with chronic otitis media with tympanic membrane perforation were operated between January 1998 and October 2003 at the Department of Otolaryngology, Hyogo College of Medicine. Cholesteatoma and tympanic adhesion were not included. Twentytwo ears (7.0%) of 16 patients were infected with MRSA. Eighteen ears were fresh cases, and were examined retrospectively in this study. Seven ears were from male patients and 11 ears were from female patients. The patients’ mean age was 48.9 years (range, 6–64 years). The average follow-up period was 38.4 months (range, 6–74 months). On the other hand, 33 ears (10.4%) of 31 cases were infected with MSSA. Thirty-one ears were fresh cases, and were examined retrospectively in this study. Eleven ears were from male and 20 ears were from female patients. The patients’ mean age was 47.9 years (range, 5–73 years). The average follow-up period was 16.8 months (range, 6–63 months). We reviewed the postoperative results of 18 MRSA-infected ears and 31 MSSA-infected ears. In each group, the patients were divided into mastoidectomy and non-mastoidectomy groups. In MRSA ears, tympanoplasty with mastoidectomy consisted of 10 ears (55.6%), and that without mastoidectomy were 8 ears (44.4%); in MSSA ears, 11 ears (35.5%) and 20 ears (64.5%), respectively. Furthermore, they were divided into patients with discharging and dry ears. In MRSA ears, discharging ears at the time of operation numbered 13 ears (72.2%), and dry ears numbered 5 ears (27.8%); in MSSA Table 1 Characteristics of the patient group
ears, 26 ears (83.9%) and 5 ears (16.1%), respectively (Table 1). The postoperative results were compared between mastoidectomy and non-mastoidectomy groups concerning graft success rate, hearing results and other complications. The graft success was defined as closure of tympanic membrane perforation after operation. Non-parametric statistics were applied using Fisher’s exact test. A pvalue < 0.05 was considered significant. Operations were performed by three experienced surgeons. Basically, whether or not mastoidectomy should be done depends on surgeons’ decision during operation. Mastoidectomy was performed by intact canal wall technique with posterior tympanotomy, i.e. opening of facial recess. Antibiotics sensitive to MRSA or MSSA was used postoperatively in all ears. In discharging ears, antibiotics was used both pre- and postoperatively.
3. Results In 18 MRSA ears, the graft success rate was 90.0% in the mastoidectomy group, and 62.5% in the non-mastoidectomy group ( p = 0.410); in 13 ears with discharge at the time of operation, 88.9% was in the mastoidectomy group and 25.0% in the non-mastoidectomy group ( p = 0.098), with no significant difference between the two groups. In 31 MSSA ears, the graft success rate was 81.8% in the mastoidectomy group and 80.0% in the non-mastoidectomy group ( p = 0.725); in 26 ears with discharge at the time of operation, it was 81.8% in the mastoidectomy group, and 80.0% in the non-mastoidectomy group ( p = 0.698), with no significant difference between the two groups (Table 2). Hearing success rate was evaluated by guidelines of the Otological Society of Japan (2000) [15]. It has three parameters: air–bone gap (ABG) less than 15 dB, hearing gain more than 15 dB and hearing level less than 30 dB. When one of these parameters is qualified, it is termed
T. Mutoh et al. / Auris Nasus Larynx 34 (2007) 9–13
11
Table 2 Graft success rates
*
Not significant ( p = 0.098);
**
not significant ( p = 0.410);
***
not significant ( p = 0.698);
hearing success. The postoperative hearing must be assessed at least 6 months after surgery. According to the guidelines, the success rate of MRSA-infected ears was 100% in the mastoidectomy group and 87.5% in the non-mastoidectomy group ( p = 0.908). In the 13 ears with discharge at the time of operation, the success rate was 100% in the mastoidectomy group and 75.0% in the non-mastoidectomy group ( p = 0.665), with no significant difference between the two groups. On the other hand, the success rate of MSSAinfected ears was 81.8% in the mastoidectomy group and
****
not significant ( p = 0.725);
*****
not significant ( p = 0.899).
90.0% in the non-mastoidectomy group ( p = 0.928). In 26 ears with discharge at the time of operation, the success rate was 81.8% in the mastoidectomy group and 86.7% in the non-mastoidectomy group ( p = 0.832), with no significant difference between the two groups (Table 3). When the hearing results were examined by ABG, ABG of all MRSA-infected ears was less than 20 dB. There was no the significant difference between the mastoidectomy group and the non-mastoidectomy group, and between discharging and dry ears. ABG of MSSA-infected ears was
Table 3 Hearing success rate using guidelines of the Otological Society of Japan (2000) [15]
*
Not significant ( p = 0.665);
**
not significant ( p = 0.908);
***
not significant ( p = 0.832);
****
not significant ( p = 0.928);
*****
not significant ( p = 0.742).
12
T. Mutoh et al. / Auris Nasus Larynx 34 (2007) 9–13
Table 4 Hearing results of air–bone gap
less than 30 dB except for 1 ear. There was no significant difference between the mastoidectomy group and the nonmastoidectomy group, or between discharging and dry ears (Table 4). We examined the rate of postoperative complications such as ear drum perforation, persistent otorrhea and dehiscence of the skin incision. It was 20.0% in the mastoidectomy group and 50.0% in the non-mastoidectomy group. There was no significant difference between the two groups ( p = 0.402). When the rate of complications was compared only in discharging ears, it was 2/9 (22.2%) in the mastoidectomy group and 4/4 (100%) in the non-
Table 5 Postoperative complication rates in discharging and dry ears (MRSA)
*
Significant ( p = 0.046);
**
not significant ( p = 0.402).
mastoidectomy group, which was significantly different ( p = 0.046) (Table 5).
4. Discussion Some surgeons prefer tympanoplasty with mastoidectomy, especially for discharging ears in chronic otitis media [9,10], and others recommend mastoidectomy whether the ear is discharging or not [11,12]. On the other hand, some surgeons have the opinion that it is unnecessary for all tympanoplasties [13,14]. However, the efficacy of
T. Mutoh et al. / Auris Nasus Larynx 34 (2007) 9–13
mastoidectomy on chronic otitis media caused by multiantibiotic resistant bacterium or MRSA has not yet been investigated. In this study, the efficacy of mastoidectomy was investigated in 18 ears of otitis media caused by MRSA with multiple resistance to antibiotics, and in 31 ears of otitis media caused by MSSA. MRSA and MSSA otitis media showed almost the same results in graft success rate and postoperative hearing between the mastoidectomy and nonmastoidectomy groups except for the following two points. First, in discharging MRSA ears, the mastoidectomy group had a significantly lower risk of postoperative complications than the non-mastoidectomy group. Second, the mastoidectomy group (8/9, 89.9%) tended to have a better graft success rate than the non-mastoidectomy group (1/4, 25.0%) in discharging MRSA ears. Therefore, it is suggested that mastoidectomy is an effective procedure in MRSA-infected chronic otitis media with otorrhea, while mastoidectomy is not necessary in MSSA-infected otitis media. In the present series, whether or not mastoidectomy is done depends on surgeons’ decision. Non-mastoidectomy group included four discharging ears with MRSA infection. In these four ears, preoperative bacterial culture was reported MRSA just after operation. Therefore, surgeons were not aware of MRSA infection at the time of operation, and they carried out operation according to their own decision. Non-mastoidectomy group also included 15 discharging patients with MSSA infection. In these 15 cases, surgeons decided necessity of mastoidectomy with their own decision. Anyway, the present study is a retrospective study and there was no criteria to perform mastoidectomy. The prevalence of MRSA has recently increased globally. In the USA, the incidence of MRSA was 2.4% of all S. aureus in 1975, 29% in 1991 and 40% in 1996 [1–3]. In Taiwan, MRSA was detected at 15.1% in chronic otitis media and the percentage of S. aureus isolates was 28.6% between 2000 and 2001 [6]. In Japan, the percentage of MRSA among S. aureus isolates in chronic otitis media was 22.3% in 80 university hospitals, 79 affiliated hospitals and 103 general practitioners between 1998 and 1999 [7]. In our hospital, MRSA was detected at 16.2% in chronic otitis media and MRSA was found at 40.0% among S. aureus isolates (data were not shown). As the rate of chronic otitis media caused by MRSA is increasing, we will have more opportunities to perform surgery. The present study showed that the tympanoplasty with mastoidectomy group had better results only in MRSAinfected otitis media with discharge at the time of operation. The possible reasons are as follows: when chronic otitis media is infected by bacteria sensitive to antibiotics, performing tympanoplasty without mastoidectomy normalizes middle ear cavity, and postoperative antibiotics can decrease the amount of bacteria; however, when chronic
13
otitis media is infected by multiple resistant bacteria, especially MRSA, performing tympanoplasty without mastoidectomy cannot remove granulation in the mastoid cavity, postoperative antibiotics are not sufficient to decrease bacterial numbers, inflammation persists.
5. Conclusion Mastoidectomy produced significantly better results concerning postoperative complications in discharging ears with MRSA-infected chronic otitis media. Therefore, we recommend performing tympanoplasty with mastoidectomy in treating MRSA-infected otitis media.
References [1] Boyce JM. Increasing prevalence of methicillin-resistant Staphylococcus aureus in US. Infec Control Hosp Epidemiol 1990;11:639–42. [2] Panlilio AL, Culver DH, Gaynes RP, Banerjee S, Henderson TS, Tolson JS, et al. Methicllin-resistant Staphylococcus aureus in US hospitals. Infec Control Hosp Epidemiol 1992;13:582–6. [3] Fluckiger U, Widmer AF. Epidemiology of methicillin-resistant Staphylococcus aureus infection. Chemotherapy 1999;45:121–34. [4] Voss A, Milatovic D, Wallrauch-Schwarz C, Rosdahl VT, Braveny I. Methicillin-resistant Staphylococcus aureus in Europe. Eur J Clin Microbiol Infect Dis 1994;13:50–5. [5] Boyce JM. Understanding and controlling methicillin-resistant Staphylococcus aureus infection. Infec Control Hosp Epidemiol 2002;23:485–7. [6] Hwang JH, Chu CK, Liu TC. Changes in bacteriology of discharging ears. J Laryngol Otol 2002;116:686–9. [7] Suzuki K, Nishimura T, Baba S. Current status of bacterial resistance in the otolaryngology field: results from the Second Nationwide Survey in Japan. J Infect Chemother 2003;9:46–52. [8] Lau T, Tos M. Long-term results of surgery for chronic granulating otitis. Am J Otolaryngol 1986;7:341–5. [9] Tos M. Indications for surgery and preoperative management. In: Tos M, editor. Manual of middle ear surgery. New York: Raven Press; 1993. p. 5. [10] Vartiainen E, Kansanen M. Tympanomastoidectomy for chronic otitis media without cholesteatoma. Otolaryngol Head Neck Surg 1992;106:230–4. [11] Sheehy JL. Mastoidectomy: the intact canal wall procedure. In: Brackmann DE, editor. Otologic surgery. Philadelphia: Raven Press; 1994. p. 211–24. [12] McGrew BM, Jackson CG, Glasscock ME. Impact of mastoidectomy on simple tympanic membrane perforation repair. Laryngoscope 2004;114:506–11. [13] Balyan FR, Celikkanat S, Aslan A, Taibah A, Russo A, Sanna M. Mastoidectomy in noncholesteatomatous chronic suppurative otitis media: is it necessary? Otolaryngol Head Neck Surg 1997;117:592–5. [14] Mishiro Y, Sakagami M, Takahashi Y, Kitahara T, Kajikawa H, Kubo T. Tympanoplasty with and without mastoidectomy for non-cholesteatomatous chronic otitis media. Eur Arch Otorhinolaryngol 2001;258:13–5. [15] A guideline in reporting hearing results in middle ear and mastoid surgery (2000). Otol Jpn 2001; 11:62–3 [in Japanese].
Efficacy of mastoidectomy on MRSA-infected chronic otitis media with tympanic membrane perforation§ Toshihiko Mutoh *, Osamu Adachi, Kojiro Tsuji, Mieko Okunaka, Masafumi Sakagami Department of Otolaryngology, Hyogo College of Medicine, 1-1 Mukogawa, Nishinomiya City, Hyogo 663-8501, Japan Received 10 February 2006; accepted 26 May 2006 Available online 21 August 2006
Abstract Objectives: To retrospectively evaluate the efficacy of mastoidectomy on methicillin-resistant Staphylococcus aureus (MRSA)-infected chronic otitis media in comparison with methicillin-susceptible Staphylococcus aureus (MSSA)-infected otitis media. Methods: Between January 1998 and October 2003, 18 ears underwent surgery for MRSA-infected chronic otitis media with tympanic membrane perforation at the Department of Otolaryngology, Hyogo College of Medicine. Another 33 ears underwent surgery for MSSAinfected chronic otitis media with tympanic membrane perforation during the same period. The postoperative results of graft success rate, hearing results and other complications were compared between MRSA-infected and MSSA-infected ears with or without mastoidectomy, and discharging or dry ears. Results: In MRSA, the mastoidectomy group tended to have a better graft success rate than the non-mastoidectomy group. In MSSA, there were almost the same graft success rate and hearing results between the mastoidectomy and non-mastoidectomy groups regardless of the presence of discharge. In MRSA-infected discharging ears, the rate of postoperative complications (ear drum perforation, persistent otorrhea, and dehiscence of skin incision) were significantly lower in the mastoidectomy group than in the non-mastoidectomy group ( p = 0.046). Conclusion: Mastoidectomy had significantly better results concerning postoperative complications in discharging ears with MRSA-infected chronic otitis media. We recommend performing tympanoplasty with mastoidectomy in MRSA-infected chronic otitis media. # 2006 Elsevier Ireland Ltd. All rights reserved. Keywords: Mastoidectomy; MRSA; MSSA; Chronic otitis media; Tympanic perforation
1. Introduction Recently, hospital-acquired infection and antibiotics abuse have led to the increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in various fields in many countries [1–5]. MRSA-infected chronic otitis media has also increased [6,7]. It is difficult to eradicate bacteria from MRSA-infected chronic otitis media, and otorrhea continues in spite of antibiotic treatment for MRSA and washing out the tympanic cavity with a physiological saline solution. It remains controversial whether or not surgical therapy is necessary in MRSA§ This study was partly presented at the 105th Annual Meeting of the OtoRhino-Laryngological Society of Japan, May 13–15, 2004, Hiroshima. * Corresponding author. Tel.: +81 798 456493; fax: +81 798 418976. E-mail address: [email protected] (T. Mutoh).
infected ears. Operation for cholesteatoma with MRSA infection is an accepted course because of possible complications such as intracranial complication, labyrinthine fistula and facial palsy. On the other hand, some surgeons refuse operations for MRSA-infected otitis media with tympanic membrane perforation. It has been commonly believed that mastoidectomy is an effective procedure for the control of middle ear inflammation [8–12]. However, recent clinical studies have given rise to questions and reported that there is no significant difference in the rate of perforation closure and in hearing results between with and without mastoidectomy [13,14]. We perform tympanoplasty with mastoidectomy when otorrhea is persistent, and perform tympanoplasty without mastoidectomy when it is absent. In MRSA-infected chronic otitis media, we have also actively performed tympanoplasty after controlling otorrhea as much as possible with medical
0385-8146/$ – see front matter # 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.anl.2006.05.017
10
T. Mutoh et al. / Auris Nasus Larynx 34 (2007) 9–13
treatment. In this study, we retrospectively compared postoperative results between MRSA-infected chronic otitis media and methicillin-susceptible Staphylococcus aureus (MSSA)-infected chronic otitis media and evaluated the efficacy of mastoidectomy in MRSA-infected chronic otitis media.
2. Materials and methods Three hundred and sixteen ears with chronic otitis media with tympanic membrane perforation were operated between January 1998 and October 2003 at the Department of Otolaryngology, Hyogo College of Medicine. Cholesteatoma and tympanic adhesion were not included. Twentytwo ears (7.0%) of 16 patients were infected with MRSA. Eighteen ears were fresh cases, and were examined retrospectively in this study. Seven ears were from male patients and 11 ears were from female patients. The patients’ mean age was 48.9 years (range, 6–64 years). The average follow-up period was 38.4 months (range, 6–74 months). On the other hand, 33 ears (10.4%) of 31 cases were infected with MSSA. Thirty-one ears were fresh cases, and were examined retrospectively in this study. Eleven ears were from male and 20 ears were from female patients. The patients’ mean age was 47.9 years (range, 5–73 years). The average follow-up period was 16.8 months (range, 6–63 months). We reviewed the postoperative results of 18 MRSA-infected ears and 31 MSSA-infected ears. In each group, the patients were divided into mastoidectomy and non-mastoidectomy groups. In MRSA ears, tympanoplasty with mastoidectomy consisted of 10 ears (55.6%), and that without mastoidectomy were 8 ears (44.4%); in MSSA ears, 11 ears (35.5%) and 20 ears (64.5%), respectively. Furthermore, they were divided into patients with discharging and dry ears. In MRSA ears, discharging ears at the time of operation numbered 13 ears (72.2%), and dry ears numbered 5 ears (27.8%); in MSSA Table 1 Characteristics of the patient group
ears, 26 ears (83.9%) and 5 ears (16.1%), respectively (Table 1). The postoperative results were compared between mastoidectomy and non-mastoidectomy groups concerning graft success rate, hearing results and other complications. The graft success was defined as closure of tympanic membrane perforation after operation. Non-parametric statistics were applied using Fisher’s exact test. A pvalue < 0.05 was considered significant. Operations were performed by three experienced surgeons. Basically, whether or not mastoidectomy should be done depends on surgeons’ decision during operation. Mastoidectomy was performed by intact canal wall technique with posterior tympanotomy, i.e. opening of facial recess. Antibiotics sensitive to MRSA or MSSA was used postoperatively in all ears. In discharging ears, antibiotics was used both pre- and postoperatively.
3. Results In 18 MRSA ears, the graft success rate was 90.0% in the mastoidectomy group, and 62.5% in the non-mastoidectomy group ( p = 0.410); in 13 ears with discharge at the time of operation, 88.9% was in the mastoidectomy group and 25.0% in the non-mastoidectomy group ( p = 0.098), with no significant difference between the two groups. In 31 MSSA ears, the graft success rate was 81.8% in the mastoidectomy group and 80.0% in the non-mastoidectomy group ( p = 0.725); in 26 ears with discharge at the time of operation, it was 81.8% in the mastoidectomy group, and 80.0% in the non-mastoidectomy group ( p = 0.698), with no significant difference between the two groups (Table 2). Hearing success rate was evaluated by guidelines of the Otological Society of Japan (2000) [15]. It has three parameters: air–bone gap (ABG) less than 15 dB, hearing gain more than 15 dB and hearing level less than 30 dB. When one of these parameters is qualified, it is termed
T. Mutoh et al. / Auris Nasus Larynx 34 (2007) 9–13
11
Table 2 Graft success rates
*
Not significant ( p = 0.098);
**
not significant ( p = 0.410);
***
not significant ( p = 0.698);
hearing success. The postoperative hearing must be assessed at least 6 months after surgery. According to the guidelines, the success rate of MRSA-infected ears was 100% in the mastoidectomy group and 87.5% in the non-mastoidectomy group ( p = 0.908). In the 13 ears with discharge at the time of operation, the success rate was 100% in the mastoidectomy group and 75.0% in the non-mastoidectomy group ( p = 0.665), with no significant difference between the two groups. On the other hand, the success rate of MSSAinfected ears was 81.8% in the mastoidectomy group and
****
not significant ( p = 0.725);
*****
not significant ( p = 0.899).
90.0% in the non-mastoidectomy group ( p = 0.928). In 26 ears with discharge at the time of operation, the success rate was 81.8% in the mastoidectomy group and 86.7% in the non-mastoidectomy group ( p = 0.832), with no significant difference between the two groups (Table 3). When the hearing results were examined by ABG, ABG of all MRSA-infected ears was less than 20 dB. There was no the significant difference between the mastoidectomy group and the non-mastoidectomy group, and between discharging and dry ears. ABG of MSSA-infected ears was
Table 3 Hearing success rate using guidelines of the Otological Society of Japan (2000) [15]
*
Not significant ( p = 0.665);
**
not significant ( p = 0.908);
***
not significant ( p = 0.832);
****
not significant ( p = 0.928);
*****
not significant ( p = 0.742).
12
T. Mutoh et al. / Auris Nasus Larynx 34 (2007) 9–13
Table 4 Hearing results of air–bone gap
less than 30 dB except for 1 ear. There was no significant difference between the mastoidectomy group and the nonmastoidectomy group, or between discharging and dry ears (Table 4). We examined the rate of postoperative complications such as ear drum perforation, persistent otorrhea and dehiscence of the skin incision. It was 20.0% in the mastoidectomy group and 50.0% in the non-mastoidectomy group. There was no significant difference between the two groups ( p = 0.402). When the rate of complications was compared only in discharging ears, it was 2/9 (22.2%) in the mastoidectomy group and 4/4 (100%) in the non-
Table 5 Postoperative complication rates in discharging and dry ears (MRSA)
*
Significant ( p = 0.046);
**
not significant ( p = 0.402).
mastoidectomy group, which was significantly different ( p = 0.046) (Table 5).
4. Discussion Some surgeons prefer tympanoplasty with mastoidectomy, especially for discharging ears in chronic otitis media [9,10], and others recommend mastoidectomy whether the ear is discharging or not [11,12]. On the other hand, some surgeons have the opinion that it is unnecessary for all tympanoplasties [13,14]. However, the efficacy of
T. Mutoh et al. / Auris Nasus Larynx 34 (2007) 9–13
mastoidectomy on chronic otitis media caused by multiantibiotic resistant bacterium or MRSA has not yet been investigated. In this study, the efficacy of mastoidectomy was investigated in 18 ears of otitis media caused by MRSA with multiple resistance to antibiotics, and in 31 ears of otitis media caused by MSSA. MRSA and MSSA otitis media showed almost the same results in graft success rate and postoperative hearing between the mastoidectomy and nonmastoidectomy groups except for the following two points. First, in discharging MRSA ears, the mastoidectomy group had a significantly lower risk of postoperative complications than the non-mastoidectomy group. Second, the mastoidectomy group (8/9, 89.9%) tended to have a better graft success rate than the non-mastoidectomy group (1/4, 25.0%) in discharging MRSA ears. Therefore, it is suggested that mastoidectomy is an effective procedure in MRSA-infected chronic otitis media with otorrhea, while mastoidectomy is not necessary in MSSA-infected otitis media. In the present series, whether or not mastoidectomy is done depends on surgeons’ decision. Non-mastoidectomy group included four discharging ears with MRSA infection. In these four ears, preoperative bacterial culture was reported MRSA just after operation. Therefore, surgeons were not aware of MRSA infection at the time of operation, and they carried out operation according to their own decision. Non-mastoidectomy group also included 15 discharging patients with MSSA infection. In these 15 cases, surgeons decided necessity of mastoidectomy with their own decision. Anyway, the present study is a retrospective study and there was no criteria to perform mastoidectomy. The prevalence of MRSA has recently increased globally. In the USA, the incidence of MRSA was 2.4% of all S. aureus in 1975, 29% in 1991 and 40% in 1996 [1–3]. In Taiwan, MRSA was detected at 15.1% in chronic otitis media and the percentage of S. aureus isolates was 28.6% between 2000 and 2001 [6]. In Japan, the percentage of MRSA among S. aureus isolates in chronic otitis media was 22.3% in 80 university hospitals, 79 affiliated hospitals and 103 general practitioners between 1998 and 1999 [7]. In our hospital, MRSA was detected at 16.2% in chronic otitis media and MRSA was found at 40.0% among S. aureus isolates (data were not shown). As the rate of chronic otitis media caused by MRSA is increasing, we will have more opportunities to perform surgery. The present study showed that the tympanoplasty with mastoidectomy group had better results only in MRSAinfected otitis media with discharge at the time of operation. The possible reasons are as follows: when chronic otitis media is infected by bacteria sensitive to antibiotics, performing tympanoplasty without mastoidectomy normalizes middle ear cavity, and postoperative antibiotics can decrease the amount of bacteria; however, when chronic
13
otitis media is infected by multiple resistant bacteria, especially MRSA, performing tympanoplasty without mastoidectomy cannot remove granulation in the mastoid cavity, postoperative antibiotics are not sufficient to decrease bacterial numbers, inflammation persists.
5. Conclusion Mastoidectomy produced significantly better results concerning postoperative complications in discharging ears with MRSA-infected chronic otitis media. Therefore, we recommend performing tympanoplasty with mastoidectomy in treating MRSA-infected otitis media.
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