Removal Of Incus Research Articles

Monograph on Tympanosclerosis-Clinico-Pathological Corelation and Surgical Outcome: A Retrospective Study.

A retrospective study was conducted at a tertiary ENT care hospital with following aims, methodology and results: (1) To know the incidence of tympanosclerosis. (2) To classify tympanosclerosis surgically as well as histologically. (3) To know the long term hearing outcome of Tympanosclerosis surgery. It is a retrospective study at an ENT Hospital Centre in eastern India. Hospital ethical board clearance was duly obtained. All cases of tympanosclerosis were documented with special reference to surgical procedure, areas of involvement and postoperative hearing outcome. In this study, 90 cases of tympanosclerosis was found in 1880 cases of tympanomastoidectomies in 8years and had been divided into (1) Myringosclerosis (60 cases, 66.6%), (2) Ossicular Tympanosclerosis without involvement of footplate (23 cases, 25.6%), (3) Ossicular Tympanosclerosis with involvement of footplate (7 cases, 7.8%). Treatment options included osssicular mobilization keeping ossicular integrity and mobility, Total or partial ossicular prosthesis after removal of incus & stapes suprastructure, stapedectomy with Long malleus-footplate piston. Overall good hearing outcome (i.e., postoperative air-bone gap less than 20dB) was noticed in 85.5% of cases of Tympanosclerosis. Removal of tympanosclerosis with keeping the osssicular chain intact is the key to success; results are not favourable if footplate is totally fixed with disease.

The Effect of the Status of the Ossicular Chain and Choice of Graft Material on Hearing Outcomes in Pediatric Cholesteatoma Surgery

Objective: Compare hearing benefit of incus preservation in primary cholesteatoma surgery versus cartilage-myringostapediopexy.Methods: Prospective cohort study in a tertiary referral center. Tympanoplasty utilizing cartilage or other grafts, with or without intact incus was performed in 195 ears (187 children) with intact stapes. Outcome measures were pre and post-operative four-tone air conduction (AC) threshold (0.5, 1, 2, 4 kHz) and proportion with normal hearing (AC ≤ 30 dB HL) at 12 months.Results: Ears with intact ossicles had better post-operative AC thresholds than those with incus eroded or removed (median 20 dB HL vs. 30 dB HL, Mann–Whitney P < .001). The normal hearing rate was 81/106 (74%) with intact incus and 46/89 (52%) without (Fisher’s exact P = .001). Ears without intact incus and a cartilage-myringostapediopexy had better post-operative thresholds than those with a non-cartilage graft (28.8 dB HL vs. 36.3 dB HL, Mann–Whitney P = .005). Of ears without intact incus, 37/59 (63%) with a cartilage-myringostapediopexy and 9/30 (30%) with a non-cartilage graft had normal hearing post-operatively (Fisher’s exact P = .007). By preserving the incus in 12 ears, 1 more ear would have normal hearing than with incus removal plus cartilage-myringostapediopexy (NNT = 12 (CI 3.6-); Fisher’s exact = 0.1).Conclusion: Preserving an intact ossicular chain conveys a small but significant hearing benefit in cholesteatoma surgery, the magnitude of which should be considered before deciding to remove the intact incus. Cartilage-myringostapediopexy provides a significant gain in hearing when the incus is absent, even without a partial ossicular replacement prosthesis.

Image-guided surgical navigation for bone-conduction hearing device implant placement

IntroductionFor pediatric patients, bone-conduction hearing devices (BCHD) have demonstrated excellent outcomes. Unique to this population, BCHD implant surgeries can be technically challenging in children due to thinner, developing bone and syndromes with atypical anatomy. Image-guided surgical navigation (IGSN) clarifies underlying skull structure, potentially improving outcomes. IGSN is commonly used in otorhinolaryngologic surgeries, but current use in BCHD placement surgeries remains unprecedented. We report favorable results of IGSN in BCHD implantation for three children with complex otologic anatomy: two syndromic patients with variable temporal bone thickness, and one with prior mastoidectomies. The three patients each underwent a successful hearing implant surgery without significant intra- or post-surgical complications. All patients had good audiologic outcomes. Methods and materialsWe report using IGSN to assist in BAHA or BONEBRIDGE™ implant surgery for three medically complicated patients. For stereotactic imaging, the patients each received pre-operative high-resolution CT scans using the paranasal sinus fusion protocol without contrast.The first patient was a 6-year-old male with CHARGE-associated abnormal temporal bone anatomy, atretic left auditory nerve, and bilateral chronic tympanic membrane perforation and otorrhea resulting in bilateral mixed conductive and sensorineural hearing loss. The patient thus was unable to consistently tolerate hearing aids.The second patient was an 18-year-old male with Rosai-Dorfman disease, history of bilateral chronic mastoiditis and middle ear infections, bilateral mastoidectomies, and bilateral malleus and incus removal resulting in mixed conductive and sensorineural hearing loss.The third patient was an 11-year-old male with Treacher Collins Syndrome, bilateral microtia, and bilateral atresia of the external auditory canals resulting in bilateral conductive hearing loss. ResultsThe patients each underwent a successful hearing implant surgery without significant intra- or post-surgical complications. All patients had good audiologic outcomes. ConclusionIntraoperative IGSN can be a beneficial adjunct to BCHD implant placement surgeries for pediatric patients with abnormal temporal bone anatomy. IGSN can help identify the optimal surgical implantation sites, thereby reducing the risk for major morbidities associated with BCHD implantations. Furthermore, our findings expand application of IGSN use to placement of both BAHA and BONEBRIDGE™.

Parameters for novel incus replacement prostheses.

Prostheses replacing the incus in its normal position and equipped with two joints might transfer sound as effectively as the intact ossicular chain and allow adjustment to quasi-static pressure changes. A prerequisite for prostheses development is the access to dimensions and distances of the ossicular chain which are necessary to conceptualize shape and size. Fifteen cadaveric human temporal bone specimens were investigated by means of micro-CT followed by 3D analysis. Each specimen was scanned three times: after removal of incus, after additional removal of the malleus head, and after approaching the umbo to the promontory. Artificial umbo medialization as a surrogate for quasi-static pressure changes leads to relevant variations in the distance between the upper part of the malleus and the stapes. Prostheses replacing the incus in its normal position should be equipped with a sliding ball joint or similar construction to allow adjustment to quasi-static pressure changes.

How to Eradicate CSF Leak in the Postoperative Course of Vestibular Schwannoma, Exclusively Using Transpetrosal Approaches

Objective: To report eradication of postoperative meningitis and cerebrospinal fluid (CSF) leak after vestibular schwannoma (VS) surgery. Methods: We analyzed a series of 400 consecutive patients who underwent surgical removal of VS via transpetrosal approaches (translabyrinthine approach [TLA] or widened retrolabyrinthine approaches [WRLA]). At the time of closing the surgical approach, all opened mastoid air cells surrounding the internal auditory meatus were filled with bone wax. In WRLA, the middle ear was preserved and the aditus blocked by a single thick piece of bone wax. In TLA, the eustachian tube was tightly closed through the epitympanum with several small pieces of the same material after incus removal. In both, fibrin glue was used to stabilize the fat graft and prevent CSF leakage. This graft consisted of two separate pieces of fat and secured with glue, before wound closure. Results: There were 191 men and 209 women. Mean age was 51.9 years (range, 11-80 years). Tumor size was Koos stage 1 in 35 cases, stage 2 in 128 cases, stage 3 in 84 cases, and stage 4 in 153. TLA was used in 281 patients and WRLA in 119 cases. Mortality was absent. No patient had a CSF fistula. Only one case of meningitis was observed, following a wound abscess. Conclusion: We have observed that postoperative complications related to the CSF fistulas were not a fatality and could be avoided in transpetrosal approaches with a very simple but cautions technique of closure.

Trans-Aditus Approach: An Alternative Technique for Cochlear Implantation

The objective of this study was to report our preliminary experience with an alternative technique for cochlear implantation. Twenty patients underwent cochlear implantation via a trans-aditus ad antrum approach to the round window. The main steps involved in the surgical procedure are cortical mastoidectomy, elevation of tympanomeatal flap, incudostapedial joint dislocation, incus removal, preparation of a bed for the implant, cochleostomy via the external auditory canal, and finally insertion of the electrode into the cochlea via the aditus. Twenty-five implants were performed on 20 patients, 18 children (mean age of 3.2years) and 2 adults. Twelve patients were males and eight were females. All the children were pre-lingual while the adults were post-lingual. Nucleus freedom cochlear implant system (Cochlear, Lane Cover, NSW, Australia) was used in four patients and a cochlear Nucleus 5 was used in six patients. A Med-el SONATA implant (MED-EL, Innsbruck, Austria) was used in 15 patients. The minimum follow-up was 5months. Here, we describe a new alternative technique for cochlear implantation and report our preliminary results. The procedure has advantages over the existing techniques and avoids the potential complications of posterior tympanotomy, transcanal, and transmeatal techniques.

A Self-Adjusting Ossicular Prosthesis Containing Polyurethane Sponge

Middle ear ossicular replacement prostheses whose length can adjust in vivo to changes in middle ear dimensions following insertion may have acoustic advantages. Optimal tension is an important factor in the acoustic performance of incus-stapes replacement prostheses. Length is the primary determinant of postinsertion tension with conventional prostheses. Postoperative changes in prosthesis tension may occur leading to a worsening of postoperative hearing. Testing of a self-adjusting prosthesis (SAP) containing a polyurethane sponge attached to the head of a titanium partial ossicular replacement prosthesis (PORP) was performed in 5 fresh temporal bones. This SAP was compared with optimal length PORPs at different tensions. Sound input was 80 dB sound pressure level at 0.1 to 10 kHz. Stapes footplate displacement was measured using a laser Doppler vibrometer before and after incus removal and after PORP and SAP insertion between the malleus and stapes. One to 3 glass shims were then inserted between the malleus and optimal length PORP and SAP to change prosthesis tension. Measurement of stapes displacement was repeated with increased prosthesis lengths of 0.15, 0.30, and 0.45 mm. There was a clear tendency in the optimal length PORPs for a decrease in footplate displacement below 1.0 kHz, in general proportional to the increasing length. The SAP provided equivalent transmission as the optimal length PORP below 4.0 kHz and better transmission below 1.0 kHz at the varying increased lengths. An SAP seems to decrease the effect of changes in prosthesis length between the malleus and stapes at lower frequencies.

How to Avoid CSF Leak or Meningitis in the Postoperative Course of Vestibular Schwannoma: Our Experience of 345 Cases over 6 Years

Purpose: To report eradication of postoperative meningitis and CSF leak after vestibular schwannoma (VS) surgery and understand why and how it is possible to avoid such complications. Methods: A retrospective review in a tertiary referral center. We analyzed a series of 350 consecutive patients who underwent surgical removal of VS from 1999 to 2006 via transpetrosal approaches (translabyrinthine approach (TLA) or widened retrolabyrinthine approaches (WRLA)). At the time of closing the surgical approach, all opened mastoid air cells were filled with bone wax, with particular attention to those surrounding the internal auditory meatus. In WRLA, the middle ear was preserved and the aditus blocked by a single thick piece of pericranium, harvested before drilling. In TLA, the eustachian tube was tightly closed through the epitympanum with several small pieces of the same material after incus removal. In both, fibrin glue was used to stabilize the fat graft and prevent CSF leakage. This graft consisted of two separate pieces of fat. The first one was inserted between the posterior dura and the otic capsule (WRLA) or the rest of the labyrinth (TLA). The second one, which was larger, was installed to fill up the remaining bone defect and was secured with glue before wound closure. Antibioprophylaxis with cefazolin was systematically used. No lumbar drainage was used. Results: There were 169 men and 176 women. Mean age was 51.9 years (11 to 80 yrs). Tumor size was Koos stage 1 in 28 cases, stage 2 in 107 cases, stage 3 in 80 cases, and stage 4 in 130. TLA was used in 221 patients and WRLA in 124 cases. Mortality was absent. No patient had a CSF fistula. No meningitis was observed. Conclusion: Postoperative complications due to CSF fistulas may be avoided in transpetrosal approaches with a very simple but cautious closure technique.

Long-term middle-ear effects of middle-ear/eustachian tube packing after translabyrinthine surgery.

The purpose of this study was to evaluate the long-term effect on middle ear and eustachian tube function following the packing of the middle-ear space to prevent cerebrospinal fluid rhinorrhoea at the termination of translabyrinthine vestibular schwannoma removal. This was an observational study of a sample of 14 patients examined between two and five years post-operatively. Photo-otoscopy and tympanometry were performed bilaterally to evaluate appearance and function. All operated middle ears were air-containing although eight out of 14 showed scarring as evidence of operative intervention. There were no drum retractions. Ten out of 14 middle-ear compliance peaks were lower in the operated ear with four flat traces. Two out of 14 were the same and two out of 14 showed high compliance. The middle-ear pressure was always within the normal range when determinable. This technique appears to have no detrimental effects on the middle ear and does not permanently obliterate the eustachian tube. The reduced compliance in the majority of cases is probably a result of scarring and fibrosis. When drum hypermobility is seen this is accounted for by incus removal.

Control of responding by the location of sound: role of binaural cues.

In auditory localization experiments, where the subject observes from a fixed position, both relative sound intensity and arrival time at the two ears determine the extent of localization performance. The present experiment investigated the role of binaural cues in a different context, the sound-position discrimination task, where the subject is free to move and interact with the sound source. The role of binaural cues was investigated in rats by producing an interaural imbalance through unilateral removal of the middle auditory ossicle (incus) prior to discrimination training. Discrete trial go-right/go-left sound-position discrimination of unilaterally incudectomised rats was then compared with that of normal rats and of rats with the incus of both sides removed. While bilateral incus removal affected binaural intensity and arrival times, the symmetry of sound input between the two ears was preserved. Percentage of correct responses and videotaped observations of sound approach and exploration showed that the unilateral rats failed to localize the sounding speaker. Rats with symmetrical binaural input (normal and bilaterally incudectomised rats) accurately discriminated sound position for the duration of the experiment. Previously reported monaural localization based upon following the intensity gradient to the sound source was not observed in the unilaterally incudectomised rats of the present experiment. It is concluded that sound-position discrimination depends upon the use of binaural cues.