Otology & Neurotology 34:1576Y1580 Ó 2013, Otology & Neurotology, Inc.
Factors Affecting Fenestration of the Footplate in Stapes Surgery: Effectiveness of Fisch’s Reversal Steps Stapedotomy *Hiromi Ueda, *Mayuko Kishimoto, *Yasue Uchida, and †Michihiko Sone *Department of Otorhinolaryngology, Aichi Medical University School of Medicine, Aichi; and ÞDepartment of Otorhinolaryngology, Nagoya University School of Medicine, Nagoya, Japan
Objective: To analyze the factors affecting the fenestration of the footplate in stapes surgery and to evaluate the effectiveness of Fisch’s reversal steps stapedotomy. Study Design: Retrospective study. Patients: A total of 191 patients with otosclerosis in whom 230 primary stapes surgeries were performed by 1 surgeon in 3 tertiary hospitals. Main Outcome Measure: Evaluation of factors affecting the fenestration of the footplate in stapes surgery by logistic regression analysis. Results: Stapedotomy (small hole in stapes footplate) was performed in 148 ears (64.3%). Partial stapedectomy (half removal of stapes footplate) was performed in 65 ears (28.3%). Total stapedectomy (total removal of stapes footplate) was performed in 17 ears (7.4%). Stapedotomy could be performed in 72.1% of cases (75/104) in which the stapes suprastructure was
removed after insertion of the prosthesis and in 57.9% of cases (73/126) in which the stapes suprastructure was removed before the insertion. Stapedotomy could be performed in 65.4% of cases (117/179) in which a 0.6-mm-thick Schuknecht-type Teflon wire piston was used and in 60.8% (31/51) in which a whole Teflon piston was used. Multivariate analysis of factors affect stapedotomy using logistic regression analysis showed that the surgical order of the removal of the stapes suprastructure and insertion of the prosthesis were the most important 2 factors. Conclusion: Fisch’s reversal steps technique was useful in performing stapedotomy in all otosclerosis patients. Manipulation of the prosthesis when crimping it to the incus is also important. The prosthesis should be crimped onto the incus and inserted in the footplate opening gently and atraumatically. Key Words: Footplate complicationsVOtosclerosisVStapedotomy. Otol Neurotol 34:1576Y1580, 2013.
In Japan, patients with otosclerosis were considered to be relatively rare compared with those in Western countries. However, the number of patients with otosclerosis has increased recently, and there has been a corresponding increase in the number of patients who have undergone stapes surgery. Lesions of otosclerosis in Japanese patients tend to be mild and less detectable on computed tomographic imaging compared with those in European countries (1,2). Footplate incidents (mobilized, floating, or fractured footplate) were reported to occur significantly more frequently when the computed tomographic scan was negative or doubtful (2). From this report, it is assumed that Japanese patients with otosclerosis would also tend to have footplate incidents. In classic stapedotomy, the stapes arch is removed first. Then, a small perforation is made in the footplate, and
finally, the prosthesis is inserted into the vestibule and placed on the incus. During these steps, footplate incidents such as floating or fracturing of the footplate may occur during removal of the stapes arch or when making a small hole in the footplate. In our early surgical period, we made a small hole in the stapes footplate before the removal of the stapes arch to allow easy treatment in case of footplate incidents (3). To prevent footplate incidents, Fisch (4) presented a complete reversal of the procedural steps of classical stapedectomy. He started with perforation of the footplate, then introduced the prosthesis, and finally, he removed the stapes arch by cutting the posterior crus and crushing the anterior crus. With his method, footplate incidents can be prevented when making a small hole in the footplate because the suprastructure of the stapes fixes the footplate. Total stapedectomy can be prevented when removing the stapes arch because the prosthesis fixes the footplate. However, the anterior part of the footplate is sometimes removed when crushing the anterior crus. We have usually used the Fisch method in our later surgical period.
Address correspondence and reprint requests to Hiromi Ueda, M.D., Department of Otorhinolaryngology, Aichi Medical University School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan; E-mail: [email protected] The authors disclose no conflicts of interest.
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Copyright © 2013 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
FACTORS AFFECTING STAPES SURGERY In this study, we retrospectively investigated the surgical findings of our patients with otosclerosis and analyzed factors affecting fenestration of the footplate in stapes surgery by logistic regression analysis. MATERIALS AND METHODS From August 1, 1991, through December 31, 2011, 230 ears of 191 patients with otosclerosis underwent stapes surgery performed by a single surgeon at Nagoya University Hospital and Japanese Red Cross Nagoya Daiichi Hospital, Nagoya, Japan, or Aichi Medical University Hospital, Nagakute City, Japan. Of the patients, 124 (64.9%) were women, and 67 (35.1%) were men. Postoperative audiometric data were obtained 3 to 12 months after surgery. Calculation of hearing results was in accordance with the 1995 American Academy of OtolaryngologyYHead and Neck Surgery guidelines (5). The mean of the thresholds at 2 and 4 kHz was used to represent thresholds at 3 kHz. The surgeon (H. U.), the approach (transcanal), and the atticotomy with a chisel were the same for all patients. In our early surgical period until 1999, the order of manipulation at surgery was as follows. First, a control hole was made in the stapes footplate to prevent the footplate from floating. Then, the incudostapedial joint was separated, the stapedial tendon was severed, the posterior crus was cut with a skeeter drill or a crurotomy scissors, the anterior crus was fractured with a hook, and the suprastructure of the stapes was removed. Next, a small fenestra of 0.8 mm was made using a Fisch’s manual microperforator (stapedotomy). Finally, a 0.6-mm-thick Schuknecht-type Teflon wire piston (Gyrus, MA, USA) was inserted into the footplate opening and crimped onto the incus. Small pieces of connective tissues were placed around the piston and sealed with fibrin glue when either one half (partial stapedectomy) or all (total stapedectomy) of the footplate was removed. In our later surgical period, from 1999 on, the reversal steps technique devised by Fisch (4) was mainly performed. First, a small fenestra of 0.8 mm was made using a Fisch’s manual microperforator, and the Teflon wire piston was inserted and crimped onto the incus. Then, the suprastructure of the stapes was removed. However, in patients with a narrow oval niche, the stapes suprastructure was removed first. In some of the surgeries, a KTP laser or CO2 laser was used to cut the posterior crus and make a small fenestra. After 2007, a whole Teflon piston (Gyrus) was mainly used instead of the wire piston. We used the W2 test to compare postoperative success rates and logistic regression analysis to predict which factors affected stapedotomy. We evaluated postoperative hearing results 3 to 12 months after surgery. The variables included in the logistic regression analysis were sex (male versus female), patient age (e50 versus 950 yr), side (right versus left), laterality (bilateral versus unilateral), order of removal of the stapes suprastructure (before prosthesis insertion versus after prosthesis insertion), prosthesis (wire piston versus piston), laser use (yes versus no), and preoperative air-bone gap (e30 dB versus 930 dB). A value of p G 0.05 was considered to indicate statistical significance. Statistical analyses were performed with StatFlex version 6 statistical software (Artech Co., Osaka, Japan).
RESULTS Demographic and clinical characteristics of the patients and the 230 ears are shown in Table 1. Stapedotomy (small hole in the stapes footplate) was performed in 148 ears
TABLE 1.
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Demographic and clinical characteristics of the patients (230 ears)
Characteristic
No. (%)
Sex Male Female Age (yr) Mean (range) e50 950 Side Right Left Laterality Bilateral Unilateral Size of fenestra Small hole Half removal Total removal Removal of stapes suprastructure Before insertion After insertion Prosthesis Wire piston Piston Laser use Yes No Preoperative air-bone gap Mean (range) e30 dB 930 dB
79 (34.3) 151 (65.7) 45.6 (10Y75) 148 (64.3) 82 (35.7) 130 (56.5) 100 (43.5) 179 (77.8) 51 (22.2) 148 (64.3) 65 (28.3) 17 (7.4) 126 (54.8) 104 (45.2) 179 (77.8) 51 (22.2) 15 (6.5) 215 (93.5) 29.5 (6.9Y60.6) 124 (53.9) 106 (46.1)
(64.3%). Partial stapedectomy (half removal of the stapes footplate) was performed in 65 ears (28.3%), and total stapedectomy (complete removal of the stapes footplate) was performed in 17 ears (7.4%). Removal of the stapes suprastructure before prosthesis insertion was performed in 126 ears (54.8%), whereas that after prosthesis insertion was performed in 104 ears (45.2%). Of all cases in which the stapes suprastructure was removed before prosthesis insertion, a fractured footplate occurred together with stapes suprastructure removal in 34 cases or with creation of a hole in the stapes footplate in 19 cases. Of all cases in which the stapes suprastructure was removed after prosthesis insertion, half of the stapes footplate (mainly the anterior portion) was removed together with the stapes suprastructure in 28 cases. Air-bone gap closure to within 10 dB was achieved in 76.4% of cases (113/148) after stapedotomy, in 78.5% of cases (51/65) after partial stapedectomy, and in 82.4% of cases (14/17) after total stapedectomy (Table 2), and the difference between these 3 patient groups was not significant. Air-bone gap closure to within 10 dB was achieved in 75.4% of cases (95/126) in which the stapes suprastructure was removed before insertion of the prosthesis and in 79.8% of cases (83/104) in which the stapes suprastructure was removed after the insertion (Table 3). The latter cases showed slightly better, but not significantly different, results. Results of univariate analysis of factors affecting stapedotomy using logistic regression analysis are shown Otology & Neurotology, Vol. 34, No. 9, 2013
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TABLE 2. Success rate (closure of postoperative air-bone gap to within 10 dB) by size of the fenestra Size of fenestra Small hole Half removal Total removal Total
No. of ears (%)
No. of successful ears (%)
148 (64.3) 65 (28.3) 17 (7.4) 230 (100)
113 (76.4) 51 (78.5) 14 (82.4) 178 (77.0)
in Table 4. Surgical order of the removal of stapes suprastructure and insertion of the prosthesis was only the significant factor for whether stapedotomy could be performed. Results of multivariate analysis of factors affecting stapedotomy using logistic regression analysis are shown in Table 5. Two indicators, order of removal of stapes suprastructure and type of piston used, were found to be the significant factors for whether stapedotomy could be performed. Stapedotomy could be performed in 72.1% of cases (75/104) in which the stapes suprastructure was removed after insertion of the prosthesis and in 57.9% of cases (73/126) in which the stapes suprastructure was removed before prosthesis insertion. Stapedotomy could be achieved more frequently in cases in which the stapes suprastructure was removed after insertion of the prosthesis. The other factor showing a statistically significant effect was the type of prosthesis used. Stapedotomy could be performed in 65.4% of cases (117/179) in which the 0.6-mm-thick Schuknecht-type Teflon wire piston was used and in 60.8% of cases (31/51) in which the whole Teflon piston was used, indicating that stapedotomy could be achieved more frequently in cases in which the Schuknecht-type Teflon wire piston was used. Other than these 2 factors, no other factors significantly affected stapedotomy. DISCUSSION Stapedotomy is reported to yield more stable hearing results over a long period and is considered to be the method of choice (6Y8). Therefore, we always try to create a small hole in the stapes footplate during stapes surgery. Sometimes, however, partial or total stapedectomy was performed as a result. Our results show that the incidence of stapedotomy was significantly increased in the patients with insertion of the prosthesis before removal of the stapes suprastructure compared with insertion of the prosthesis after removal of the suprastructure. This result agreed with that of Szymacski et al. (9), although they recommended
TABLE 3. Success rate (closure of postoperative air-bone gap to within 10 dB) by order of removal of stapes suprastructure Removal of stapes suprastructure Before insertion After insertion Total
No. of ears (%)
No. of successful ears(%)
126 (54.8) 104 (45.2) 230 (100)
95 (75.4) 83 (79.8) 178 (77.0)
TABLE 4.
Univariate logistic regression analysis of 230 ears
Factors Removal of stapes suprastructure Preoperative air-bone gap Sex Surgical period Prosthesis Laterality Side Laser use Age (yr)
Contrast
p
After versus before e30 dB versus 930 dB Male versus female First versus latter half Piston versus wire piston Unilateral versus bilateral Left versus right Yes versus no e50 versus 950
0.026 0.061 0.075 0.271 0.547 0.578 0.708 0.717 0.946
the use of a CO2 laser to create the small hole in the stapes footplate. We also used a CO2 or KTP laser to create this small hole and to cut the posterior crus of the stapes in some of our surgeries. However, we could detect no difference in our findings in relation to laser use. We could not cut the anterior crus of the stapes with the laser after insertion of the prosthesis because the prosthesis blocked manipulations, and therefore, we had to crush the anterior crus. Furthermore, the anterior part of the stapes footplate was rarely removed together with the stapes footplate during manipulations to remove the stapes suprastructure. We believe this was the reason why laser use was not so effective. In 2008, Malafronte et al. (10) reported that patients with otosclerosis were differentiated into 2 groups by footplate color, and the incidence of footplate complications was higher in patients with white versus blue otosclerosis. In addition, they indicated that the use of the reversal steps technique by Fisch was not recommended in patients with white otosclerosis because the technique did not avoid incus luxation and footplate complications such as fracture and luxation of the anterior half (11). Sometimes, we could not judge whether the otosclerosis was white or blue, and even if the anterior half of the footplate was removed together with the stapes suprastructure, we placed connective tissue around the piston and sealed it with fibrin glue instead of replacing the prosthesis. There were no incidences of perilymphatic fistula postoperatively. We could apply
TABLE 5. Factors Removal of stapes suprastructure Prosthesis Sex Laterality Preoperative air-bone gap Surgical period Laser use Side Age (yr)
Multivariate logistic regression analysis of 230 ears Contrast
p
OR (95% CI)
After versus before
0.010
6.80 (1.59Y29.14)
Piston versus wire piston Male versus female Unilateral versus bilateral e30 dB versus 930 dB First versus latter half Yes versus no Left versus right e50 versus 950
0.046
0.41 (0.17Y0.99)
0.058 0.074
1.83 (0.98Y3.43) 0.56 (0.29Y1.06)
0.133
0.64 (0.36Y1.15)
0.250
0.65(0.31Y1.35)
0.412 0.562 0.974
0.61 (0.19Y1.97) 1.19 (0.66Y2.18) 1.01 (0.55Y1.86)
CI indicates confidence interval; OR, odds ratio.
Otology & Neurotology, Vol. 34, No. 9, 2013
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FACTORS AFFECTING STAPES SURGERY the reversal steps technique by Fisch in all patients with otosclerosis except for those with a narrow oval window. Even in cases with a narrow oval window, Fisch (8) recommended the use of a 0.4-mm wire Teflon piston by reversal steps stapedotomy because it achieved better hearing results and was less traumatic to the inner ear than stapedectomy. However, some patients with a very narrow oval window because of overhang of the facial nerve require insertion of the prosthesis after removal of the stapes suprastructure because even making a small hole in the stapes footplate is difficult if the stapes suprastructure is not removed. The influence of prosthesis diameter in stapes surgery has generated some controversial reports. Hu¨ttenbrink (12) reported that pistons with a diameter of 0.4 mm and above should have similar sound transmission properties and that a large diameter might have a small but clinically insignificant effect on hearing results. He also indicated that reduced potential inner-ear trauma with a smaller diameter piston had to be considered. In contrast, Laske et al. (13) concluded from their meta-analysis that a 0.6-mm diameter piston prosthesis was associated with significantly better results than those with a 0.4-mm prosthesis, and it should be used if the surgical conditions allow it. Now, we think that the use of a 0.4-mm prosthesis might be considered in patients with a narrow oval window. As for postoperative hearing results, rate of air-bone gap closure to within 10 dB in the cases in which the stapes suprastructure was removed after insertion of the prosthesis was slightly but not significantly better than that in the cases in which the stapes suprastructure was removed before the insertion. Hughes (14) reported that there was a significant learning curve associated with stapes surgery in terms of postoperative hearing results. In fact, we removed the stapes suprastructure before insertion of the prosthesis in our early surgical period, and this may be one reason why attainment of air-bone gap closure to within 10 dB in the cases in which the stapes suprastructure was removed after insertion of the prosthesis was slightly better than that in the cases of stapes suprastructure removal before insertion. Sargent (15) indicated that stapedotomy has led to reliable results with a learning curve that seems less protracted than that with the mostly stapedectomy technique performed by Hughes. In addition, our results showed that surgical period was not a significant factor affecting stapedotomy (Tables 4 and 5). We think that a learning curve is not a factor affecting stapedotomy. The second significant factor was the type of prosthesis used. In Japan, only 2 kinds of the prostheses are permitted by the medical insurance system. The use of a whole Teflon piston significantly decreased the incidence of stapedotomy. When we crimp a whole Teflon piston onto the long process of the incus, we need to push the piston onto the long process. Sometimes, the footplate is mobilized with this manipulation, and then the anterior part of the stapes footplate is removed together with the stapes footplate in manipulations to remove the stapes suprastructure. The use of the wire piston is favorable at
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this point, but the wire piston has ferromagnetic properties. Syms (16) reported that performing magnetic resonance imaging (MRI) with a 1.5- or 3.0-Tesla system on patients with stapes prostheses was safe as indicated by survey results and animal experiments. However, MRI systems of higher Tesla strength will be used in the future. In addition, crimping the wire piston by a single maneuver with a microforceps sometimes causes incomplete adhesion of the prosthetic loop and erosion of the long process of the incus (17). It seems that the use of a whole Teflon piston or a prosthesis without ferromagnetic properties and which allows complete adhesion of the prosthetic loop together with easy crimping to the incus is most desirable. When using a whole Teflon piston, care should be taken to fit the piston to the incus and to insert it in the footplate opening gently and atraumatically.
CONCLUSION Fisch’s reversal steps technique was useful in performing stapedotomy in all of our otosclerosis patients except for those with a narrow oval window. In cases in which the anterior portion of the footplate is extracted together with removal of the stapes suprastructure, we recommend packing connective tissue around the hole of the oval window instead of removing the prosthesis and sealing with fibrin glue. Manipulation of the prosthesis when crimping it to the incus is also important. The prosthesis should be crimped onto the incus and inserted in the footplate opening gently and atraumatically.
REFERENCES 1. Kiyomizu K, Tono T, Yang D, Haruta A, Kodama T, Komune S. Correlation of CT analysis and audiometry in Japanese otosclerosis. Auris Nasus Larynx 2004;31:125Y9. 2. Lagleyre S, Sorrentino T, Calmels M, et al. Reliability of highresolution CT scan in diagnosis of otosclerosis. Otol Neurotol 2009;30:1152Y9. 3. Ueda H, Miyazawa T, Asahi K, Yanagita N. Factors affecting hearing results after stapes surgery. J Laryngol Otol 1999;113:417Y21. 4. Fisch U. Tympanoplasty, Mastoidectomy and Stapes Surgery. New York, NY: Thieme Medical Publishers, 1994:214Y27. 5. Committee on Hearing and Equilibrium guidelines for the evaluation of results of treatment of a conductive loss. Otolaryngol Head Neck Surg 1995;113:186Y7. 6. Somers T, Govaerts P, Marquet T, Offeciers E. Statistical analysis of otosclerosis surgery performed by Jean Marquet. Ann Otol Rhinol Laryngol 1994;103:945Y51. 7. Persson P, Harder H, Magnuson B. Hearing results in otosclerosis surgery after partial stapedectomy, total stapedectomy and stapedotomy. Acta Otolaryngol 1997;117:94Y9. 8. Fisch U. Stapedotomy versus stapedectomy. Am J Otol 1982;4: 112Y7. 9. Szymacski M, Gol&bek W, Morshed K, Siwiec H. The influence of the sequence of surgical steps on complications rate in stapedotomy. Otol Neurotol 2007;28:152Y6. 10. Malafronte G, Filosa B, Cantone E. New macroscopic classification of stapedio-ovalar otosclerosis: a simplified rating for training in stapedotomy. Otol Neurotol 2008;29:889Y92. 11. Malafronte G, Filosa B. Fisch’s reversal steps stapedotomy: when to use it? Otol Neurotol 2009;30:1128Y30. Otology & Neurotology, Vol. 34, No. 9, 2013
Copyright © 2013 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
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12. Hu¨ttenbrink KB. Biomechanics of stapesplasty: a review. Otol Neurotol 2003;24:548Y59. 13. Laske RD, Ro¨o¨sli C, Chatzimichalis MV, Sim JH, Huber AM. The influence of prosthesis diameter in stapes surgery: a meta-analysis and systemic review of the literature. Otol Neurotol 2011;32:520Y28. 14. Hughes GB. The learning curve in stapes surgery. Laryngoscope 1991;101(12 Pt 1):1280Y4.
15. Sargent EW. The learning curve revisited: stapedotomy. Otolaryngol Head Neck Surg 2002;126:20Y5. 16. Syms MJ. Safety of magnetic resonance imaging of stapes prostheses. Laryngoscope 2005;115:381Y90. 17. Fontana M, Ferri E, Lola L, Babighian G. A scanning electron microscopic study of crimping of stapedial prostheses. Auris Nasus Larynx 2011;39:461Y8.
Otology & Neurotology, Vol. 34, No. 9, 2013
Copyright © 2013 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
Factors Affecting Fenestration of the Footplate in Stapes Surgery: Effectiveness of Fisch’s Reversal Steps Stapedotomy *Hiromi Ueda, *Mayuko Kishimoto, *Yasue Uchida, and †Michihiko Sone *Department of Otorhinolaryngology, Aichi Medical University School of Medicine, Aichi; and ÞDepartment of Otorhinolaryngology, Nagoya University School of Medicine, Nagoya, Japan
Objective: To analyze the factors affecting the fenestration of the footplate in stapes surgery and to evaluate the effectiveness of Fisch’s reversal steps stapedotomy. Study Design: Retrospective study. Patients: A total of 191 patients with otosclerosis in whom 230 primary stapes surgeries were performed by 1 surgeon in 3 tertiary hospitals. Main Outcome Measure: Evaluation of factors affecting the fenestration of the footplate in stapes surgery by logistic regression analysis. Results: Stapedotomy (small hole in stapes footplate) was performed in 148 ears (64.3%). Partial stapedectomy (half removal of stapes footplate) was performed in 65 ears (28.3%). Total stapedectomy (total removal of stapes footplate) was performed in 17 ears (7.4%). Stapedotomy could be performed in 72.1% of cases (75/104) in which the stapes suprastructure was
removed after insertion of the prosthesis and in 57.9% of cases (73/126) in which the stapes suprastructure was removed before the insertion. Stapedotomy could be performed in 65.4% of cases (117/179) in which a 0.6-mm-thick Schuknecht-type Teflon wire piston was used and in 60.8% (31/51) in which a whole Teflon piston was used. Multivariate analysis of factors affect stapedotomy using logistic regression analysis showed that the surgical order of the removal of the stapes suprastructure and insertion of the prosthesis were the most important 2 factors. Conclusion: Fisch’s reversal steps technique was useful in performing stapedotomy in all otosclerosis patients. Manipulation of the prosthesis when crimping it to the incus is also important. The prosthesis should be crimped onto the incus and inserted in the footplate opening gently and atraumatically. Key Words: Footplate complicationsVOtosclerosisVStapedotomy. Otol Neurotol 34:1576Y1580, 2013.
In Japan, patients with otosclerosis were considered to be relatively rare compared with those in Western countries. However, the number of patients with otosclerosis has increased recently, and there has been a corresponding increase in the number of patients who have undergone stapes surgery. Lesions of otosclerosis in Japanese patients tend to be mild and less detectable on computed tomographic imaging compared with those in European countries (1,2). Footplate incidents (mobilized, floating, or fractured footplate) were reported to occur significantly more frequently when the computed tomographic scan was negative or doubtful (2). From this report, it is assumed that Japanese patients with otosclerosis would also tend to have footplate incidents. In classic stapedotomy, the stapes arch is removed first. Then, a small perforation is made in the footplate, and
finally, the prosthesis is inserted into the vestibule and placed on the incus. During these steps, footplate incidents such as floating or fracturing of the footplate may occur during removal of the stapes arch or when making a small hole in the footplate. In our early surgical period, we made a small hole in the stapes footplate before the removal of the stapes arch to allow easy treatment in case of footplate incidents (3). To prevent footplate incidents, Fisch (4) presented a complete reversal of the procedural steps of classical stapedectomy. He started with perforation of the footplate, then introduced the prosthesis, and finally, he removed the stapes arch by cutting the posterior crus and crushing the anterior crus. With his method, footplate incidents can be prevented when making a small hole in the footplate because the suprastructure of the stapes fixes the footplate. Total stapedectomy can be prevented when removing the stapes arch because the prosthesis fixes the footplate. However, the anterior part of the footplate is sometimes removed when crushing the anterior crus. We have usually used the Fisch method in our later surgical period.
Address correspondence and reprint requests to Hiromi Ueda, M.D., Department of Otorhinolaryngology, Aichi Medical University School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan; E-mail: [email protected] The authors disclose no conflicts of interest.
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Copyright © 2013 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
FACTORS AFFECTING STAPES SURGERY In this study, we retrospectively investigated the surgical findings of our patients with otosclerosis and analyzed factors affecting fenestration of the footplate in stapes surgery by logistic regression analysis. MATERIALS AND METHODS From August 1, 1991, through December 31, 2011, 230 ears of 191 patients with otosclerosis underwent stapes surgery performed by a single surgeon at Nagoya University Hospital and Japanese Red Cross Nagoya Daiichi Hospital, Nagoya, Japan, or Aichi Medical University Hospital, Nagakute City, Japan. Of the patients, 124 (64.9%) were women, and 67 (35.1%) were men. Postoperative audiometric data were obtained 3 to 12 months after surgery. Calculation of hearing results was in accordance with the 1995 American Academy of OtolaryngologyYHead and Neck Surgery guidelines (5). The mean of the thresholds at 2 and 4 kHz was used to represent thresholds at 3 kHz. The surgeon (H. U.), the approach (transcanal), and the atticotomy with a chisel were the same for all patients. In our early surgical period until 1999, the order of manipulation at surgery was as follows. First, a control hole was made in the stapes footplate to prevent the footplate from floating. Then, the incudostapedial joint was separated, the stapedial tendon was severed, the posterior crus was cut with a skeeter drill or a crurotomy scissors, the anterior crus was fractured with a hook, and the suprastructure of the stapes was removed. Next, a small fenestra of 0.8 mm was made using a Fisch’s manual microperforator (stapedotomy). Finally, a 0.6-mm-thick Schuknecht-type Teflon wire piston (Gyrus, MA, USA) was inserted into the footplate opening and crimped onto the incus. Small pieces of connective tissues were placed around the piston and sealed with fibrin glue when either one half (partial stapedectomy) or all (total stapedectomy) of the footplate was removed. In our later surgical period, from 1999 on, the reversal steps technique devised by Fisch (4) was mainly performed. First, a small fenestra of 0.8 mm was made using a Fisch’s manual microperforator, and the Teflon wire piston was inserted and crimped onto the incus. Then, the suprastructure of the stapes was removed. However, in patients with a narrow oval niche, the stapes suprastructure was removed first. In some of the surgeries, a KTP laser or CO2 laser was used to cut the posterior crus and make a small fenestra. After 2007, a whole Teflon piston (Gyrus) was mainly used instead of the wire piston. We used the W2 test to compare postoperative success rates and logistic regression analysis to predict which factors affected stapedotomy. We evaluated postoperative hearing results 3 to 12 months after surgery. The variables included in the logistic regression analysis were sex (male versus female), patient age (e50 versus 950 yr), side (right versus left), laterality (bilateral versus unilateral), order of removal of the stapes suprastructure (before prosthesis insertion versus after prosthesis insertion), prosthesis (wire piston versus piston), laser use (yes versus no), and preoperative air-bone gap (e30 dB versus 930 dB). A value of p G 0.05 was considered to indicate statistical significance. Statistical analyses were performed with StatFlex version 6 statistical software (Artech Co., Osaka, Japan).
RESULTS Demographic and clinical characteristics of the patients and the 230 ears are shown in Table 1. Stapedotomy (small hole in the stapes footplate) was performed in 148 ears
TABLE 1.
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Demographic and clinical characteristics of the patients (230 ears)
Characteristic
No. (%)
Sex Male Female Age (yr) Mean (range) e50 950 Side Right Left Laterality Bilateral Unilateral Size of fenestra Small hole Half removal Total removal Removal of stapes suprastructure Before insertion After insertion Prosthesis Wire piston Piston Laser use Yes No Preoperative air-bone gap Mean (range) e30 dB 930 dB
79 (34.3) 151 (65.7) 45.6 (10Y75) 148 (64.3) 82 (35.7) 130 (56.5) 100 (43.5) 179 (77.8) 51 (22.2) 148 (64.3) 65 (28.3) 17 (7.4) 126 (54.8) 104 (45.2) 179 (77.8) 51 (22.2) 15 (6.5) 215 (93.5) 29.5 (6.9Y60.6) 124 (53.9) 106 (46.1)
(64.3%). Partial stapedectomy (half removal of the stapes footplate) was performed in 65 ears (28.3%), and total stapedectomy (complete removal of the stapes footplate) was performed in 17 ears (7.4%). Removal of the stapes suprastructure before prosthesis insertion was performed in 126 ears (54.8%), whereas that after prosthesis insertion was performed in 104 ears (45.2%). Of all cases in which the stapes suprastructure was removed before prosthesis insertion, a fractured footplate occurred together with stapes suprastructure removal in 34 cases or with creation of a hole in the stapes footplate in 19 cases. Of all cases in which the stapes suprastructure was removed after prosthesis insertion, half of the stapes footplate (mainly the anterior portion) was removed together with the stapes suprastructure in 28 cases. Air-bone gap closure to within 10 dB was achieved in 76.4% of cases (113/148) after stapedotomy, in 78.5% of cases (51/65) after partial stapedectomy, and in 82.4% of cases (14/17) after total stapedectomy (Table 2), and the difference between these 3 patient groups was not significant. Air-bone gap closure to within 10 dB was achieved in 75.4% of cases (95/126) in which the stapes suprastructure was removed before insertion of the prosthesis and in 79.8% of cases (83/104) in which the stapes suprastructure was removed after the insertion (Table 3). The latter cases showed slightly better, but not significantly different, results. Results of univariate analysis of factors affecting stapedotomy using logistic regression analysis are shown Otology & Neurotology, Vol. 34, No. 9, 2013
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TABLE 2. Success rate (closure of postoperative air-bone gap to within 10 dB) by size of the fenestra Size of fenestra Small hole Half removal Total removal Total
No. of ears (%)
No. of successful ears (%)
148 (64.3) 65 (28.3) 17 (7.4) 230 (100)
113 (76.4) 51 (78.5) 14 (82.4) 178 (77.0)
in Table 4. Surgical order of the removal of stapes suprastructure and insertion of the prosthesis was only the significant factor for whether stapedotomy could be performed. Results of multivariate analysis of factors affecting stapedotomy using logistic regression analysis are shown in Table 5. Two indicators, order of removal of stapes suprastructure and type of piston used, were found to be the significant factors for whether stapedotomy could be performed. Stapedotomy could be performed in 72.1% of cases (75/104) in which the stapes suprastructure was removed after insertion of the prosthesis and in 57.9% of cases (73/126) in which the stapes suprastructure was removed before prosthesis insertion. Stapedotomy could be achieved more frequently in cases in which the stapes suprastructure was removed after insertion of the prosthesis. The other factor showing a statistically significant effect was the type of prosthesis used. Stapedotomy could be performed in 65.4% of cases (117/179) in which the 0.6-mm-thick Schuknecht-type Teflon wire piston was used and in 60.8% of cases (31/51) in which the whole Teflon piston was used, indicating that stapedotomy could be achieved more frequently in cases in which the Schuknecht-type Teflon wire piston was used. Other than these 2 factors, no other factors significantly affected stapedotomy. DISCUSSION Stapedotomy is reported to yield more stable hearing results over a long period and is considered to be the method of choice (6Y8). Therefore, we always try to create a small hole in the stapes footplate during stapes surgery. Sometimes, however, partial or total stapedectomy was performed as a result. Our results show that the incidence of stapedotomy was significantly increased in the patients with insertion of the prosthesis before removal of the stapes suprastructure compared with insertion of the prosthesis after removal of the suprastructure. This result agreed with that of Szymacski et al. (9), although they recommended
TABLE 3. Success rate (closure of postoperative air-bone gap to within 10 dB) by order of removal of stapes suprastructure Removal of stapes suprastructure Before insertion After insertion Total
No. of ears (%)
No. of successful ears(%)
126 (54.8) 104 (45.2) 230 (100)
95 (75.4) 83 (79.8) 178 (77.0)
TABLE 4.
Univariate logistic regression analysis of 230 ears
Factors Removal of stapes suprastructure Preoperative air-bone gap Sex Surgical period Prosthesis Laterality Side Laser use Age (yr)
Contrast
p
After versus before e30 dB versus 930 dB Male versus female First versus latter half Piston versus wire piston Unilateral versus bilateral Left versus right Yes versus no e50 versus 950
0.026 0.061 0.075 0.271 0.547 0.578 0.708 0.717 0.946
the use of a CO2 laser to create the small hole in the stapes footplate. We also used a CO2 or KTP laser to create this small hole and to cut the posterior crus of the stapes in some of our surgeries. However, we could detect no difference in our findings in relation to laser use. We could not cut the anterior crus of the stapes with the laser after insertion of the prosthesis because the prosthesis blocked manipulations, and therefore, we had to crush the anterior crus. Furthermore, the anterior part of the stapes footplate was rarely removed together with the stapes footplate during manipulations to remove the stapes suprastructure. We believe this was the reason why laser use was not so effective. In 2008, Malafronte et al. (10) reported that patients with otosclerosis were differentiated into 2 groups by footplate color, and the incidence of footplate complications was higher in patients with white versus blue otosclerosis. In addition, they indicated that the use of the reversal steps technique by Fisch was not recommended in patients with white otosclerosis because the technique did not avoid incus luxation and footplate complications such as fracture and luxation of the anterior half (11). Sometimes, we could not judge whether the otosclerosis was white or blue, and even if the anterior half of the footplate was removed together with the stapes suprastructure, we placed connective tissue around the piston and sealed it with fibrin glue instead of replacing the prosthesis. There were no incidences of perilymphatic fistula postoperatively. We could apply
TABLE 5. Factors Removal of stapes suprastructure Prosthesis Sex Laterality Preoperative air-bone gap Surgical period Laser use Side Age (yr)
Multivariate logistic regression analysis of 230 ears Contrast
p
OR (95% CI)
After versus before
0.010
6.80 (1.59Y29.14)
Piston versus wire piston Male versus female Unilateral versus bilateral e30 dB versus 930 dB First versus latter half Yes versus no Left versus right e50 versus 950
0.046
0.41 (0.17Y0.99)
0.058 0.074
1.83 (0.98Y3.43) 0.56 (0.29Y1.06)
0.133
0.64 (0.36Y1.15)
0.250
0.65(0.31Y1.35)
0.412 0.562 0.974
0.61 (0.19Y1.97) 1.19 (0.66Y2.18) 1.01 (0.55Y1.86)
CI indicates confidence interval; OR, odds ratio.
Otology & Neurotology, Vol. 34, No. 9, 2013
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FACTORS AFFECTING STAPES SURGERY the reversal steps technique by Fisch in all patients with otosclerosis except for those with a narrow oval window. Even in cases with a narrow oval window, Fisch (8) recommended the use of a 0.4-mm wire Teflon piston by reversal steps stapedotomy because it achieved better hearing results and was less traumatic to the inner ear than stapedectomy. However, some patients with a very narrow oval window because of overhang of the facial nerve require insertion of the prosthesis after removal of the stapes suprastructure because even making a small hole in the stapes footplate is difficult if the stapes suprastructure is not removed. The influence of prosthesis diameter in stapes surgery has generated some controversial reports. Hu¨ttenbrink (12) reported that pistons with a diameter of 0.4 mm and above should have similar sound transmission properties and that a large diameter might have a small but clinically insignificant effect on hearing results. He also indicated that reduced potential inner-ear trauma with a smaller diameter piston had to be considered. In contrast, Laske et al. (13) concluded from their meta-analysis that a 0.6-mm diameter piston prosthesis was associated with significantly better results than those with a 0.4-mm prosthesis, and it should be used if the surgical conditions allow it. Now, we think that the use of a 0.4-mm prosthesis might be considered in patients with a narrow oval window. As for postoperative hearing results, rate of air-bone gap closure to within 10 dB in the cases in which the stapes suprastructure was removed after insertion of the prosthesis was slightly but not significantly better than that in the cases in which the stapes suprastructure was removed before the insertion. Hughes (14) reported that there was a significant learning curve associated with stapes surgery in terms of postoperative hearing results. In fact, we removed the stapes suprastructure before insertion of the prosthesis in our early surgical period, and this may be one reason why attainment of air-bone gap closure to within 10 dB in the cases in which the stapes suprastructure was removed after insertion of the prosthesis was slightly better than that in the cases of stapes suprastructure removal before insertion. Sargent (15) indicated that stapedotomy has led to reliable results with a learning curve that seems less protracted than that with the mostly stapedectomy technique performed by Hughes. In addition, our results showed that surgical period was not a significant factor affecting stapedotomy (Tables 4 and 5). We think that a learning curve is not a factor affecting stapedotomy. The second significant factor was the type of prosthesis used. In Japan, only 2 kinds of the prostheses are permitted by the medical insurance system. The use of a whole Teflon piston significantly decreased the incidence of stapedotomy. When we crimp a whole Teflon piston onto the long process of the incus, we need to push the piston onto the long process. Sometimes, the footplate is mobilized with this manipulation, and then the anterior part of the stapes footplate is removed together with the stapes footplate in manipulations to remove the stapes suprastructure. The use of the wire piston is favorable at
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this point, but the wire piston has ferromagnetic properties. Syms (16) reported that performing magnetic resonance imaging (MRI) with a 1.5- or 3.0-Tesla system on patients with stapes prostheses was safe as indicated by survey results and animal experiments. However, MRI systems of higher Tesla strength will be used in the future. In addition, crimping the wire piston by a single maneuver with a microforceps sometimes causes incomplete adhesion of the prosthetic loop and erosion of the long process of the incus (17). It seems that the use of a whole Teflon piston or a prosthesis without ferromagnetic properties and which allows complete adhesion of the prosthetic loop together with easy crimping to the incus is most desirable. When using a whole Teflon piston, care should be taken to fit the piston to the incus and to insert it in the footplate opening gently and atraumatically.
CONCLUSION Fisch’s reversal steps technique was useful in performing stapedotomy in all of our otosclerosis patients except for those with a narrow oval window. In cases in which the anterior portion of the footplate is extracted together with removal of the stapes suprastructure, we recommend packing connective tissue around the hole of the oval window instead of removing the prosthesis and sealing with fibrin glue. Manipulation of the prosthesis when crimping it to the incus is also important. The prosthesis should be crimped onto the incus and inserted in the footplate opening gently and atraumatically.
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12. Hu¨ttenbrink KB. Biomechanics of stapesplasty: a review. Otol Neurotol 2003;24:548Y59. 13. Laske RD, Ro¨o¨sli C, Chatzimichalis MV, Sim JH, Huber AM. The influence of prosthesis diameter in stapes surgery: a meta-analysis and systemic review of the literature. Otol Neurotol 2011;32:520Y28. 14. Hughes GB. The learning curve in stapes surgery. Laryngoscope 1991;101(12 Pt 1):1280Y4.
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