2010 Copyright @ Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited. Revision Stapedotomy: Operative Findings and Hearing Results. A Prospective Study of 652 Cases From the Otology-Neurotology Database *Robert Vincent, †Maroeska Rovers, ‡Narayan Zingade, §John Oates, kNeil Sperling, ¶Arnaud Deve `ze, and †Wilko Grolman *Causse Ear Clinic, Traverse de Be ´ziers, Colombiers, France; ÞDepartment of Otorhinolaryngology and Rudolf Magnus Institute of Neuroscience, University Medical Center, Utrecht, The Netherlands; þDepartment of ENT, JN Medical College, Belgaum, India; §Queen’s Hospital Burton upon Trent, U.K.; kDepartment of Otolaryngology, State University of New York Downstate Medical Center, Brooklyn, New York, U.S.A.; and ¶Department of Otorhinolaryngology, Hopital Nord, University of La Mediterrane ´e, Marseille, France Objective: To identify the causes of failure of primary stapes surgery and to evaluate the hearing results of revision stapes surgery in a consecutive series of 652 cases. Study Design: Prospective nonrandomized clinical study. Setting: Tertiary referral center. Patients: Six hundred thirty-four patients who underwent 652 consecutive revision stapes operations from April 1992 to December 2007 were enrolled in this study. Main Outcome Measures: Preoperative and postoperative au- diometric evaluation using conventional audiometry, namely, air- bone gap (ABG), bone-conduction thresholds, and air-conduction thresholds, were assessed. Postoperative audiometry was per- formed at 3, 6, 9, 12, 18, and 24 months and then annually for 15 years. Results: The most frequently identified reason for primary surgery failure was incus erosion (27.6%) and prosthesis dis- placement (18.2%). The postoperative ABG was closed to 10 dB or less and 20 dB or less in 63.4 and 74.6% of cases, respectively. The mean 4-frequency postoperative ABG was 11.5 dB as compared with 28 dB preoperatively (mean differ- ence, 16.5 dB; 95% confidence interval [CI], 15.1Y17.9 dB, p G 0.0001). The mean 4-frequency postoperative air-conduction thresholds were 45.7 dB compared with 58.7 dB preoperatively (mean difference, 13 dB; 95% CI, 11.4Y14.6 dB, p G 0.0001). The mean 4-frequency postoperative bone-conduction thresholds were 34 dB compared with 30.6 dB preoperatively (mean dif- ference, j3.5 dB; 95% CI, j4.4 to j2.5 dB, p G 0.0001). A significant postoperative sensorineural hearing loss (915 dB) was observed in 2.9% of cases in this series. Conclusion: Improvement of a conductive hearing loss after initial unsuccessful primary or revision stapes surgery can be accomplished with further revision but is occasionally modest. Key Words: Hearing resultsVOtology-Neurotology DatabaseV OtosclerosisVRevision surgeryVStapedotomyVStapes surgery. Otol Neurotol 31:875Y882, 2010. Surgical outcome after revision stapes surgery has con- sistently been reported as less favorable when compared with that after primary surgery. Revision surgery is also associated with a higher risk of postoperative sensorineural hearing loss (SNHL) (1Y3). Hearing results seem to be determined by the primary surgical techniques used, the cause of failure identified at revision surgery, and the revision technique (1). During the period of April 1992 to December 2007, 4,508 operations for otosclerosis were performed by the same surgeon (first author) in the same tertiary referral center. Of these 4,508 operations, 652 were revisions. The first aim of this prospective study was to evaluate the causes that led to the failure of the previous surgery. The second aim was to report hearing results of the revision surgery in a series of 652 consecutive surgical revisions performed by the same surgeon. MATERIALS AND METHODS Patients This is a prospective study of 634 patients who underwent 652 revision stapes surgeries. All patients treated between April 1992 and December 2007 were included in this study and were operated on by the same surgeon. A serial assessment of hearing Address correspondence and reprint requests to Robert Vincent, M.D., Causse Ear Clinic, Traverse de Be ´ziers, 34440 Colombiers, France; E-mail: robvinc@aol.com The authors have no conflict of interest to declare. No funding from any organization was received for this work. Otology & Neurotology 31:875Y882 Ó 2010, Otology & Neurotology, Inc. 875