Acoustic Mechanisms

1998 ◽  
Vol 118 (6) ◽  
pp. 751-761 ◽  
Author(s):  
KENNETH R. WHITTEMORE ◽  
SAUMIL N. MERCHANT ◽  
JOHN J. ROSOWSKI
Keyword(s):  
Middle Ear ◽  
Sound Transmission ◽  
Canal Wall ◽  
Air Space ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
Temporal Bones ◽  
Head Neck ◽  
Canal Wall Up ◽  
Space Volume

The contribution of the middle ear air spaces to sound transmission through the middle ear in canal wall-up and canal wall-down mastoidectomy was studied in human temporal bones by measurements of middle ear input impedance and sound pressure difference across the tympanic membrane for the frequency range 50 Hz to 5 kHz. These measurements indicate that, relative to canal wall-up procedures, canal wall-down mastoidectomy results in a 1 to 5 dB decrease in middle ear sound transmission below 1 kHz, a 0 to 10 dB increase between 1 and 3 kHz, and no change above 3 kHz. These results are consistent with those reported by Gyo et al. (Arch Otolaryngol Head Neck Surg 1986;112:1262-8), in which umbo displacement was used as a measure of sound transmission. A model analysis suggests that the reduction in sound transmission below 1 kHz can be explained by the smaller middle ear air space volume associated with the canal wall-down procedure. We conclude that as long as the middle ear air space is aerated and has a volume greater than 0.7 ml, canal wall-down mastoidectomy should generally cause less than 10 dB changes in middle ear sound transmission relative to the canal wall-up procedure. (Otolaryngol Head Neck Surg 1998;118:751-61.)

scholarly journals A New Stapes-Head Coupler for the Vibrant Soundbridge System

2021 ◽  
pp. 1-8
Author(s):  
Birthe Warnholtz ◽  
Merlin Schär ◽  
Pascale Cuny ◽  
Kathrin Sonntag ◽  
Dirk Beutner ◽  
...  
Keyword(s):  
Middle Ear ◽  
Medical Electronics ◽  
Vibrational Motion ◽  
Canal Wall ◽  
Vibrant Soundbridge ◽  
Active Middle Ear Implant ◽  
Middle Ear Implant ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
Temporal Bones

Introduction: The Vibrant Soundbridge (MED-EL Medical Electronics, Austria) is an active middle ear implant with a floating mass transducer (FMT) for patients with conductive, sensorineural, or mixed hearing loss. While the FMT is vertically aligned above the stapes head (SH) with the current Vibroplasty Clip coupler (MED-EL Medical Electronics), the new SH coupler was developed to mount the FMT on the inferior side of the stapes and to fit in the reduced middle ear space after canal-wall-down mastoidectomy. Methods: Using 11 human cadaveric temporal bones (TBs), placements of the new SH couplers on the stapes were examined, and effective stimuli to the cochlea were evaluated by measuring piston-like motion of the stapes footplate with a current of 1 mA on the FMT. The results were assessed in comparison with the Vibroplasty Clip coupler. Results: The new SH coupler showed perfect coupling on the stapes in 9 out of 11 TBs. A small gap between the SH and the plate of the connection link part was unavoidable in 2 TBs but had negligible effect on vibrational motion of the stapes. Vibrational motion of the stapes with the new SH coupler was reduced at frequencies above 3 kHz compared to the corresponding motion with the current Vibroplasty Clip coupler, but the relative attenuation over all 11 cadaveric temporal bones was <10 dB. Conclusions: The new SH coupler provides an alternative with more stable fixation when placement of the current Vibroplasty Clip coupler is limited due to insufficient space after canal-wall-down mastoidectomy, while still delivering effective stimuli to the cochlea.

scholarly journals Correlation between functional outcome and the SAMEO-ATO framework

2021 ◽  
Author(s):  
Vito Pontillo ◽  
Marialessia Damiani ◽  
Giusi Graziano ◽  
Nicola Quaranta
Keyword(s):  
Functional Outcome ◽  
Middle Ear ◽  
Petrous Bone ◽  
Canal Wall ◽  
Hearing Results ◽  
Tertiary Referral Center ◽  
Ossicular Reconstruction ◽  
Canal Wall Down ◽  
Mastoid Surgery ◽  
Canal Wall Up

Abstract Purpose To evaluate the recently proposed SAMEO-ATO framework for middle ear and mastoid surgery, by correlating it with the functional outcome in a large cohort of patients operated for middle ear and mastoid cholesteatoma in a tertiary referral center. Methods We retrospectively included all surgeries for middle ear and mastoid cholesteatoma undergone in our Department between January 2009 and December 2014, by excluding revision surgeries, congenital and petrous bone cholesteatoma. All surgeries were classified according to the SAMEO-ATO framework. The post-operative air bone gap (ABG) was calculated and chosen as benchmark parameter for the correlation analysis. Results 282 consecutive surgeries for middle ear and mastoid cholesteatoma were released in the study period on a total of 273 patients, with a mean age of 41.2 years. All patients were followed for an average period of 55.3 months. 54% of patients underwent M2c mastoidectomy (Canal Wall Down, CWD), while the remaining underwent Canal Wall Up (CWU) procedures, being M1b2a mastoidectomy the most common one (33%). Mean pre-operative and post-operative ABGs were 29.2 and 23.5 dB, with a significant improvement (p < 0.0001). ‘Mastoidectomy’ and ‘Ossicular reconstruction’ parameters of SAMEO-ATO showed significant association with postoperative ABG, with smaller residual gaps for the classes Mx and On, and worse hearing results for M3a and Ox. Conclusion Our results show the utility of SAMEO-ATO framework, and in particular of ‘M’ (Mastoidectomy) and ‘O’ (Ossicular reconstruction) parameters, in predicting the hearing outcome.

scholarly journals The depth of the facial nerve in the mastoid bone

2018 ◽  
Vol 4 (3) ◽  
pp. 666
Author(s):  
B. Y. Praveen Kumar ◽  
K. T. Chandrashekhar ◽  
M. K. Veena Pani ◽  
Sunil K. C. ◽  
Anand Kumar S. ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Significant Variation ◽  
Canal Wall ◽  
Stylomastoid Foramen ◽  
Cortical Mastoidectomy ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
The Mean ◽  
Temporal Bones

<p class="abstract"><strong>Background:</strong> The hallmark of the temporal bone is variation. Various important structures like the facial nerve run in the temporal bone at various depths which can be injured during mastoidectomy.</p><p class="abstract"><strong>Methods:</strong> Twenty wet cadaveric temporal bones were dissected. A cortical mastoidectomy was performed followed by a canal wall down mastoidectomy and the depth of the vertical segment of the facial nerve in the mastoid was determined.  </p><p class="abstract"><strong>Results:</strong> The mean depth of the second genu was 13.82 mm. The mean depth of the stylomastoid foramen was 12.75 mm and the mean distance from the annulus at 6’0 clock to the stylomastoid foramen was 10.22 mm.</p><p><strong>Conclusions:</strong> There is significant variation in the average depth of the facial nerve in the mastoid. </p>

scholarly journals Management of Benign Middle Ear Tumors: A Series of 7 Cases

2017 ◽  
Vol 96 (10-11) ◽  
pp. 426-432
Author(s):  
Z. Jason Qian ◽  
Amy M. Coffey ◽  
Kathleen M. O'Toole ◽  
Anil K. Lalwani
Keyword(s):  
Surgical Management ◽  
Middle Ear ◽  
Ossicular Chain ◽  
Clinical Findings ◽  
Mastoid Cavity ◽  
Canal Wall ◽  
Tumor Excision ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
Rare Group

Benign middle ear tumors represent a rare group of neoplasms that vary widely in their pathology, anatomy, and clinical findings. These factors have made it difficult to establish guidelines for the resection of such tumors. Here we present 7 unique cases of these rare and diverse tumors and draw from our experience to recommend optimal surgical management. Based on our experience, a postauricular incision is necessary in nearly all cases. Mastoidectomy is required for tumors that extend into the mastoid cavity. Whenever exposure or hemostasis is believed to be inadequate with simple mastoidectomy, canal-wall-down mastoidectomy should be performed. Finally, disarticulation of the ossicular chain greatly facilitates tumor excision and should be performed early in the procedure.

scholarly journals Canal wall down versus canal wall up surgeries in the treatment of middle ear cholesteatoma

2019 ◽  
Vol 49 (5) ◽  
pp. 1426-1432
Author(s):  
Recep KARAMERT ◽  
Fakih Cihat ERAVCI ◽  
Süleyman CEBECİ ◽  
Mehmet DÜZLÜ ◽  
Mehmet Ekrem ZORLU ◽  
...  
Keyword(s):  
Middle Ear ◽  
Canal Wall ◽  
Middle Ear Cholesteatoma ◽  
Canal Wall Down ◽  
Canal Wall Up

Canal wall down mastoidectomy: causes of failure, pitfalls and their management

1995 ◽  
Vol 109 (7) ◽  
pp. 583-589 ◽  
Author(s):  
Sanjaya Bhatia ◽  
Sandeep Karmarkar ◽  
Giuseppe DeDonato ◽  
Cemil Mutlu ◽  
Abdelkader Taibah ◽  
...  
Keyword(s):  
Middle Ear ◽  
Revision Surgery ◽  
Tympanic Membrane Perforation ◽  
Canal Wall ◽  
Revision Procedure ◽  
Primary Procedure ◽  
Membrane Perforation ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
Causes Of Failure

AbstractManaging patients with failed canal wall down mastoidectomy, requires a meticulous approach to control the disease and restore hearing. The present article reviews the causes of failure of the primary procedure and pitfalls encountered in 105 patients referred to our centre for revision canal wall down mastoidectomy. At post-revision surgery there were no cases with residual or recurrent cholesteatoma. The failures in our revision procedure were due to tympanic membrane perforation which occurred in five percent (n = 4) and intermittent otorrhoea in two percent (n = 2). A dry cavity with adequate middle ear space allowed for optimum audiological function even in revision canal wall down procedures.

scholarly journals Recidivous cholesteatoma: DWI MR after canal wall up and canal wall down mastoidectomy

2016 ◽  
Vol 117 (09) ◽  
pp. 515-520
Author(s):  
T. Bakaj ◽  
L. Bakaj Zbrozkova ◽  
R. Salzman ◽  
M. Tedla ◽  
I. Starek
Keyword(s):  
Canal Wall ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
Canal Wall Up

scholarly journals Comparison of Pre and Postoperative Hearing Results after Cartilage Augmentation Type III Tympanoplasty

1970 ◽  
Vol 1 (2) ◽  
pp. 3-5
Author(s):  
BL Shrestha ◽  
H Bhattarai ◽  
CL Bhusai
Keyword(s):  
Canal Wall ◽  
Hearing Results ◽  
Type Iii ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
Head Neck

Keywords: Air bone gap; chronic media (squamous); canal wall down mastoidectomy; cartilage augmentation type III tympanoplastyDOI: 10.3126/njenthns.v1i2.4752 Nepalese J ENT Head Neck Surg Vol.1 No.2 (2010) p.3-5

scholarly journals Hearing Benefit in Allograft Tympanoplasty Using Tutoplast Processed Malleus

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Anja Lieder ◽  
Wolfgang Issing
Keyword(s):  
Hearing Loss ◽  
Middle Ear ◽  
Conductive Hearing Loss ◽  
Canal Wall ◽  
Hearing Improvement ◽  
Safe Alternative ◽  
Hearing Thresholds ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
Conductive Hearing

Objectives.Tutoplast processed human cadaveric ossicular allografts are a safe alternative for ossicular reconstruction where there is insufficient material suitable for autograft ossiculoplasty. We present a series of 7 consecutive cases showing excellent air-bone gap closure following canal-wall-down mastoidectomy for cholesteatoma and reconstruction of the middle ear using Tutoplast processed malleus.Patients and Methods.Tympanoplasty with Tutoplast processed malleus was performed in seven patients to reconstruct the middle ear following canal-wall-down mastoidectomy in a tertiary ENT centre.Main Outcome Measures.Hearing improvement and recurrence-free period were assessed. Pre-and postoperative audiograms were performed.Results.The average pre operative hearing loss was 50 ± 13 dB, with an air-bone gap of 33 ± 7 dB. Post operative audiograms at 25 months demonstrated hearing thresholds of 29 ± 10 dB, with an air-bone gap of 14 ± 6 dB. No prosthesis extrusion was observed, which compares favourably to other commercially available prostheses.Conclusions.Tutoplast processed allografts restore conductive hearing loss in patients undergoing mastoidectomy and provide an excellent alternative when there is insufficient material suitable for autograft ossiculoplasty.

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