Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Incus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2002

[Diagnosis and therapy of stapes fractures and luxations].

BACKGROUND: Injuries of the ossicular chain have various etiologies. Skull traumas from blows to the temporal, parietal or occipital region with or without fracture of the temporal bone are the main causes of the ossicular injury; other modes of injury are rare. It depends on the type of trauma which kind of injury occurs. Mainly subluxations, luxations and fractures are to be observed. The incus is the ossicle which is the most often injured. Mostly, only one ossicle is injured, rarely two or all of them. PATIENTS: From January 1997 to June 1999 we operated 19 patients with traumatic lesions of the membrane and the middle ear. In 4 cases the reason for the operation was an injury of the stapes. We observed 2 cases with broken stapes crura, 1 case with an impression of the stapes into the vestibulum with perilymphatic fistula and 1 case with subluxation of the stapes in the direction of the promontorium. By presenting 4 cases we want to point out the diagnostic possibilities and the operative management of such rare injuries. In all cases we applied the transmeatal approach for the operation of the middle ear. In 2 cases it was possible to place the stapes back in their anatomic position in order to re-establish the ossicular chain. In the other 2 cases we had to use middle ear prostheses which were interpositioned between the manubrium of the malleus and the footplate of the stapes. RESULTS: In all cases the immediate post-operative hearing results and the long-term hearing results after 10 to 28 months were satisfying. We did not notice any post-operative complications, especially no vestibular symptoms. One patient's tinnitus was the same as before the operation. CONCLUSIONS: The diagnosis of a stapes injury is despite the use of sophisticated technology, especially the CT-scan of the temporal bone, often very difficult. A sensitive anamnesis seems to be very important. It depends on the kind of injury which operative technique is to be applied in order to re-establish the ossicular chain. In our opinion, it is useful to take - if it is possible - the autolog stapes for the surgical re-establishment of transmission.

Adult↗
PubMed2005

Cadaveric dissections based on observations of injuries to the temporal bone structures following head trauma.

One hundred temporal bones obtained from forensic autopsies were dissected to expose injured structures. Longitudinal fractures were present in 82%, transverse fractures in 11%, and mixed fractures in 7% of the cases. Facial canal injuries were present in almost half of the bones with longitudinal fractures (36/82), although cuts of the facial nerve stem were rarely encountered. Damages to the facial canal associated with longitudinal fractures were most frequently seen in the region of the geniculum. However, transverse fractures with facial canal involvement (7/11) most frequently occurred in the labyrinthine portion, causing a complete cut of the facial nerve. Injuries to the jugular bulb were also common (21/100) and associated with all types of temporal bone fractures. Observed damages to the auditory ossicles included disconnection of their joints or fractures of the malleus or stapes. Fractures of the incus were not observed. Injuries to the carotid canal were common (52/100), although an injury to the arterial wall was observed in only one specimen. The frequency and nature of damage in temporal bone fractures strictly reflect the type of fracture, especially in terms of facial nerve disorders: the most serious damage is observed with fractures that involve the otic capsule.

Journal Article↗
PubMed1999

[The Nucleus Double Array Cochlear Implant: a new concept in obliterated cochlea].

AIM: In order to increase the number of intracochlear electrodes to be inserted into a totally obliterated cochlea a special implant has been developed in collaboration with Cochlear Ltd. The implant features two separate electrode carriers containing 11 and 10 active electrodes, respectively, and a reference electrode on the receiver stimulator package. The potential stimulation modes include monopolar and bipolar stimulation as well as stimulation between both arrays. SURGICAL TECHNIQUE: A cochleostomy at the round window provides access to the scala tympani. Newly formed bone is removed as far as the anterior portion of the basal turn. Care is taken to identify and preserve the osseous border of the cochlea. A second cochleostomy is performed immediately caudal to the cochleariform process after removal of the incus. New tissue can be removed here in the same way. The two electrode carriers are then placed into the first and the second turn respectively. The remaining procedure corresponds to the procedure for cochlear implantation in cases in which the cochlea is not obliterated. PATIENTS: For the purpose of a clinical study n = 10 patients aged between 32-66 years with an obliterated cochlea were fitted with a double array cochlear implant. All patients showed signs of total obliteration of the basal turn either in preoperative imaging or during surgery. Intraoperative inspection revealed that the second turn was not obliterated in 4 of 10 patients. POSTOPERATIVE RESULTS: Postoperatively, a standard test battery was used to determine auditory performance over a period of time. All patients achieved significantly better speech understanding due to the additional apical electrode array. No complications occurred. CONCLUSION: In cases involving an obliterated cochlea, the number of intracochlear electrodes can be increased with the double array implant. As a result, the patients achieve significantly better auditory results.

Adult↗
PubMed1996

[High resolution computerized tomography of middle ear abnormalities].

BACKGROUND: The aim of this study was to analyze malformed petrous bones with computed tomography and to develop a radiologic score which can help to judge the indication for operative reconstructions. METHODS: One hundred forty-two petrous bones in 71 patients with unilateral or bilateral microtia, atresia of the external auditory canal, and malformations of the middle ear were evaluated with high-resolution CT. RESULTS: In 97% of patients with severe auricular dysplasia, there was dysplasia of the middle ear ossicles; in 70% the stapes was malformed. In 32% the oval window was occluded, and in 7% the round window. In 75%, the canal of the facial nerve was displaced, and 16% also showed abnormalities of the labyrinth. A close correlation between the malformation of the auricle and of the middle ear was not found. CONCLUSIONS: High-resolution CT is necessary for the evaluation of malformed middle ears. Based on the abnormalities described, we propose a radiologic score for the assessment of malformed petrous bones. This consists of the following criteria: external auditory meatus, pneumatization of the mastoid and of the tympanic space, size of the tympanic space, facial nerve, vessels, malleus and incus, stapes, oval and round window. The graded points of each structure are added up to the score, which might range between 0 and 28. This score can help to judge the indication for reconstruction of the middle ear. In bilateral malformation we suggest a middle ear reconstruction of the better hearing ear if the score is greater than or equal to 15, and in unilateral malformation if it is at least 20. In patients with lower scores, we only suggest hearing aids.

Adolescent↗
PubMed1995

[Suitability of various lasers for interventions from the tympanic membrane to the foot plate (Er:YAG, argon, CO2 s.p.--, Ho:YAG laser].

The Erbium:YAG-laser is a good tool for microresection of bone and soft tissue from the ear drum, to the ossicles and extending to the footplate. The mechanism of ablation is based on the fact that the emission of infrared light is of the same wavelength at which water has its peak of optimal light absorption. 14% of bone is water, just sufficient force for ablation. At 50 mJ impulses the temperature in the centre stays below the coagulation point. 500 impulses of 50 mJoule definitely remain below the acoustic risk. In 44 guinea pigs 500 x 50 mJ caused a temporal threshold shift of maximal 38 dB at 2000 cps which recovered after 90-135 min. In 60 tympanoplasties neither tinnitus nor audiological side effects of the laser application were measured. The ear drum is perforated by 1 (-3) impulses. This can be done even in children after superficial anaesthesia (2% pantocaine drops) to drain the middle ear. The laser perforation of 0.3 mm [symbol: see text] will close after a day and has to be re-opened in the office to avoid tubes. We do not yet know how often general anaesthesia and removal by suction of too viscous mucus remain nevertheless necessary. With the Er:YAG laser parts of the ossicles can be cut out of the intact chain, without contact and trauma, nearly without loss of bone tissue. This allows better radicality in removing cholesteatomas or scars with less destruction. 500 impulses of 50 mJ ablate 32 mg of bone, i.e. the weight of an incus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[A short history of hearing research. II. Renaissance].

The history of basic research on the function of the hearing organ is revisited. The present, second part of the review covers the period between the renaissance of anatomical research in the 16th century and the beginning of modern hearing research at the end of the 19th century. Andreas Vesalius gave the two ossicles malleus and incus their names. His scholar Philippus Ingrassia found 1546 the third ossicle, the stapes. The cochlea was discovered 1552 by Bartholomeus Eustachius and denoted as cochlea 1561 by Gabriel Falloppio. Thomas Willis speculated 1672 that different "tones" (species audibilis) may excite different fibres of the nervus acusticus. In collaboration with the physicist Edme Mariotte, Joseph Guichard DuVerney developed in 1683 a theory of the tonotopical organisation of the cochlea, the encoding of acoustic information by mechanical spectral analysis. The scholastic dogma of Aristotle's aer implantatus was contradicted by Domenico Cotugno as late as 1760. DuVerney's theory was, together with Georg Simon Ohm's law on the applicability of the Fourier analysis to sound waves, the basis of Hermann Helmholtz' famous theory of hearing of 1863. Due to the lack of detailed knowledge about the function of nerves, however, no clear ideas were developed about the acoustical information carried to the brain by the acoustic nerve. Also in the 19th century, Alphonso Corti discovered the organ that was named after him by Albert von Kölliker, and Flouren's experiments demonstrated the function of the vestibular organs. Furthermore, the foundations of auditory psychophysics were laid by Alfred M. Mayer and others.

Audiology↗
PubMed1989

[The value of high-resolution computerized tomography in abnormalities of the middle ear].

Middle ear malformations are common congenital disorders of the head and neck area. Recent advances in plastic and middle ear surgery have improved the prognosis of patients suffering from congenital hearing disorders. However, sophisticated preoperative procedures are mandatory. The development of HR-CT has improved the radiologic possibilities to evaluate middle ear disorders significantly. In the present study we examined by means of HR-CT twenty patients with congenital middle ear malformation. Our findings include different sizes of the middle ear as well as dysplastic alterations of the malleus and incus. The inner ear was normal in almost all cases. Our results indicate that preoperative HR-CT is a reliable diagnostic method to demonstrate middle ear disorders.

Ear Ossicles↗
PubMed2000

Revision stapedectomy.

OBJECTIVE: To evaluate results of revision stapedectomy with and without use of the laser and determine factors predictive of hearing outcome. STUDY DESIGN AND SETTING: Retrospective review of 356 revision stapedectomy operations performed at the House Ear Clinic, a tertiary neurotologic private practice, between 1983 and 1995. RESULTS: A postoperative gap of < or =10 dB was obtained in 60% of cases. Results were similar with and without the use of a laser. Sensorineural hearing loss of >10 dB occurred in 7.7%, with 3 (1.4%) ears with profound hearing loss. A poorer outcome was related to incus necrosis, multiple revisions, and indications for surgery other than conductive hearing loss. CONCLUSION: Revision stapedectomy can provide good gap closure in 60% of cases, with small risk of sensorineural hearing loss. SIGNIFICANCE: Although not as satisfactory as primary stapedectomy, revision stapedectomy can be offered to patients with reasonable expectations for good gap closure.

Adolescent↗
PubMed2001

Ventral approach to the rat middle ear for otologic research.

OBJECTIVE: To describe a simple approach to the rat middle ear because there are few clear descriptions of this technique with minimal morbidity and mortality. STUDY DESIGN AND SETTING: Six male Long-Evans rats were used in this study. We designed a cervical approach to the middle ear with the purpose of creating an experimental model of ossiculoplasty that permits the postoperative survival of the animal. RESULTS: It was possible in all cases to visualize the majority of structures of the tympanic cavity: promontory, round window, stapedial artery, stapes, incus, and tympanic membrane. There were no cases of postoperative infection or facial paralysis. CONCLUSIONS AND SIGNIFICANCE: The ventral approach to the rat middle ear is a rapid and simple technique that makes the rat the animal of choice for many otologic investigations.

Animals↗
PubMed2003

Task performance in stapedotomy: comparison between surgeons of different experience levels.

OBJECTIVES: Two steps in stapedotomy are particularly challenging: (1) micropick fenestration of the stapes footplate (SF) and (2) crimping of the stapes prosthesis (SP) to the incus. We conducted trials to determine if experience correlates with differences in performance for these tasks. METHODS: In a surgical model of stapedotomy, performance was measured for 3 experienced and 3 novice surgeons. For fenestration, we measured ability to target the fenestration and force applied to the SF. For crimping, we measured crimp quality, movement of the SP during crimping, and force applied to the SF. RESULTS: Experienced surgeons demonstrated significantly better ability to target the fenestration and, during crimping, caused less SP movement and a significantly lower rate of SP dislodgment. CONCLUSIONS: Clear differences in task performance are measurable between more and less experienced surgeons during critical steps of stapedotomy. CLINICAL SIGNIFICANCE: The observed differences in task performance may contribute to an understanding of maneuvers that increase the risk of inadequate prosthesis placement and cochlear trauma-factors likely responsible for variable hearing results with strapedotomy.

Clinical Competence↗
PubMed2002

Cochlear implantation without mastoidectomy: the pericanal electrode insertion technique.

OBJECTIVE: A new minimally invasive cochlear implantation method with direct electrode insertion through the external auditory canal (EAC) is presented. MATERIAL AND METHODS: Surgery begins with a retroauricular skin incision. The bony surface of the mastoid plane behind the ear is dissected free and the skin of the EAC is elevated together with the posterior part of the tympanic membrane. Cochleostomy is performed through the EAC with a microdrill anterior to the round window. A rim is drilled into the postero-superior region of the bony EAC immediately above the incus towards the outer border of the EAC and connected to the retroauricular surface by a short tunnel. The implant device is placed in the usual retroauricular area. The electrode is inserted through the tunnel and rim into the tympanic cavity and pushed into the cochleostomy hole. The electrode is immobilized in the rim using glass ionomer cement and covered with bone dust. After placement of the ground electrode, the retroauricular incision is closed. The tympano-meatal flap is replaced and a dressing is put into the EAC. RESULTS: The new method has been applied thus far in 15 adults and pre-adolescent deaf patients (8 females, 7 males). A MED-EL Combi 40 + device was used in 14 patients and a Nucleus CI24M in 1. Pericanal electrode insertion was easy, with insertion depths into the cochlea of > or = 30 mm with the MED-EL and of 20 mm with the Nucleus device. There were no surgical complications, infections or electrode extrusions during postoperative observation periods ranging from 6 months to > 2 years. The functional results were comparable to those obtained with cochlear implantation via mastoidectomy. The pericanal electrode insertion technique has several advantages, the most important being that the danger of facial nerve damage is minimized and that the operating time is reduced by up to 50%. CONCLUSION: Cochlear implantation with pericanal electrode insertion is a simple, fast and particularly safe option which may replace the classical transmastoidal cochlear implantation method in adults and older children.

Adolescent↗
PubMed2004

Phase III results with a totally implantable piezoelectric middle ear implant: speech audiometry, spatial hearing and psychosocial adjustment.

OBJECTIVE: To evaluate the treatment efficacy of an electromechanical middle ear amplifier implant (AI) in patients with chronic moderate-to-severe sensorineural hearing loss (SNHL). The AI is a piezoelectric system with a sound processor and a rechargeable battery within a hermetically sealed titanium canister. Its titanium-sealed microphone is placed in the bony region of the ear canal. The incus-coupled transducer (actuator), which is also inside a titanium casing, is fastened to the adjacent bone. MATERIAL AND METHODS: This was a phase III study comprising 20 intention-to-treat patients. Telemetrical adjustments followed electromechanical amplifier implantations. We used a word recognition test as our primary efficacy measure (Freiburg Speech Recognition Test: DIN 45621). Secondary efficacy measures were the sentence comprehension test (Goettinger Satztest, 1996) for auditory orientation within noisy and quiet environments and a psychosocial adjustment test (Gothenburg Profile Test, 1998). The 6-month follow-up comprised a complete medical examination. Nineteen patients completed the study (per-protocol patients; 100% reference). RESULTS: Seventeen patients (89%) demonstrated improved binaural recognition of phonetically balanced monosyllables. Fourteen postoperative patients (74%) attained a perfect score (100%) on this test, compared to only 3 preoperative patients (16%). Thirteen patients (68%) reached the sentence recognition threshold at a 2:1 dB signal-to-noise ratio during noisy trials. Correct identification of the noise source direction in the horizontal plane occurred in 89% of the trials. The Gothenburg Profile Test scores showed that the subjective evaluation of hearing, orientation, social behavior and self-confidence increased from 48% to 88%. Three patients did not benefit from the implant. CONCLUSION: Treatment of SNHL with a totally implantable hearing system can be an efficient method for those patients unable to wear hearing aids. However, in order to avoid implantation in non-responders, there is a need for more specific audiological indication criteria.

Audiometry, Pure-Tone↗
PubMed2004

Tegmen tympani cerebrospinal fluid leak repair.

OBJECTIVE: To describe the transmastoid approach for closing cerebrospinal fluid leaks in the tegmen tympani using autologous materials (temporal muscle fascia and abdominal fat) and heterologous materials (bovine collagen), together with its advantages and disadvantages. MATERIAL AND METHODS: We present the cases of three patients who underwent closure of spontaneous cerebrospinal fluid leaks in the tegmen tympani in which we used the transmastoid approach and autologous and heterologous materials. The three patients underwent canal wall-up mastoidectomy, posterior tympanotomy, removal of the malleus head and incus and, consequently, exposure of the tegmen tympani and the cerebrospinal fluid leak. Closure was performed using temporal muscle fascia, abdominal fat and bovine collagen, fixed in place with fibrin glue. A lumbar shunt was established, as is routine. RESULTS: The cerebrospinal fluid leak was closed in all patients using the technique described, with a minimum follow-up of 14 months. CONCLUSION: The technique presented herein is an excellent option in cases of cerebrospinal fluid leakage in the tegmen tympani; it is easy to perform and results in minimal risk to patients.

Adipose Tissue↗
PubMed2004

Rapid prototyping of temporal bone for surgical training and medical education.

OBJECTIVE: The skills of ear surgery are best developed by dissecting a temporal bone. However, only a limited number of trainees can be afforded this opportunity because of the scarcity of available bones. The aim of this study was to investigate the validity of a prototype temporal bone model for surgical training and education. MATERIAL AND METHODS: A simulated 3D model of a human temporal bone was made using a selective laser sintering method. The powder layers were laser-fused based on detailed CT data and accumulated to create a 3D structure. Conventional surgical instruments were used to dissect the model under a microscope. RESULTS: The model was as hard as real bone and surface structures were accurately reproduced. The model could be shaved using a surgical drill, burr and suction irrigator in the same way as a real bone. The malleus and incus were reproduced. The semicircular canals and the oval and round window niches were identified. Cavity structures, such as the semicircular canal, vestibule, antrum and air cells, were filled with powder which had to be removed using a pick and suction irrigator during dissection. A magnified model was useful for educating medical students. CONCLUSION: This prototype 3D model made using selective laser sintering serves as a good educational tool for middle ear surgery.

Humans↗
PubMed2006

Treatment of mixed hearing losses via implantation of a vibratory transducer on the round window.

Early clinical findings are reported for subjects implanted with the Vibrant Med-El Soundbridge (VSB) device. The present criteria for the VSB, limiting its application to patients with normal middle ear function, have been extended to include patients with ossicular chain defects. Seven patients with severe mixed hearing loss were implanted with the transducer placed onto the round window. All had undergone previous surgery: six had multiple ossiculoplasties, and one had the VSB crimped on the incus with unsuccessful results. Round window implantation bypasses the normal conductive path and provides amplified input to the cochlea. Post-operative aided thresholds of 30 dB HL were achieved for most subjects, as compared with unaided thresholds ranging from 60-80 dB HL. Aided speech reception thresholds at 50% intelligibility were 50 dB HL, with most subjects reaching 100% intelligibility at conversational levels, while unaided thresholds averaged 80 dB HL, with only one subject reaching 100% intelligibility. These results suggest that round window implantation may offer a viable treatment option for individuals with severe mixed hearing losses who have undergone unsuccessful ossiculoplasties.

Acoustic Stimulation↗
PubMed1974

Ultrastructure of mitosis and cytokinesis in the multinucleate green alga Acrosiphonia.

The processes of mitosis and cytokinesis in the multinucleate green alga Acrosiphonia have been examined in the light and electron microscopes. The course of events in division includes thickening of the chloroplast and migration of numerous nuclei and other cytoplasmic incusions to form a band in which mitosis occurs, while other nuclei in the same cell but not in the band do not divide. Centrioles and microtubules are associated with migrated and dividing nuclei but not with nonmigrated, nondividing nuclei. Cytokinesis is accomplished in the region of the band, by means of an annular furrow which is preceded by a hoop of microtubules. No other microtubules are associated with the furrow. Characteristics of nuclear and cell division in Acrosiphonia are compared with those of other multinucleate cells and with those of other green algae.

Cell Division↗
PubMed1995

Value of computed tomography in patients with persistent vertigo after stapes surgery.

RATIONALE AND OBJECTIVES: The value of computed tomography was evaluated in 14 patients with persistent vertigo after otosclerosis operation. METHODS: High-resolution computed tomography was performed with 1-mm slice thickness and table feed in the axial and coronal planes. RESULTS: Computed tomography scans showed in 13 case findings that related to symptoms. An air bubble at the end of the prosthesis as a new, indirect sign of a perilymphatic fistula was found in 6 cases. An incorrect position of the stapes prostheses was diagnosed in 7 patients. One patient had recurrence of otosclerosis, and two others developed scarring around the prosthesis. In 1 case, an incus necrosis was found. Some patients showed two signs simultaneously. The computed tomography results were confirmed by retympanotomy in 12 cases. CONCLUSIONS: Computed tomography proved to be a valuable method in the diagnosis of persistent vertigo after otosclerosis operation. The indication for a repeat operation was facilitated by the use of computed tomography.

Follow-Up Studies↗
PubMedDate not supplied

Evaluation of high-resolution CT after tympanoplasty.

The temporal bones of 28 patients who underwent tympanoplasty were evaluated with high-resolution CT (HRCT). Seventeen patients had undergone tympanoplasty with a columella, used to form an ossicular reconstruction. The incus body was used as the columella in 4 patients and a prosthesis was used in 13 patients. No columella was used in the other 11 patients. After tympanoplasty, CT demonstrated normal appearance in 8 patients. Of the other 20 patients, 16 were diagnosed with chronic otitis media, and 4 were diagnosed with recurrent cholesteatoma on the basis of follow-up CT examinations. Seven underwent reoperation. In all 4 patients with recurrent cholesteatoma, the diagnosis was pathologically confirmed at reoperation. In 1 patient diagnosed with chronic otitis media, the pathological diagnosis was recurrent cholesteatoma. The columellae in 8 of the 17 patients could not be identified on CT because of surrounding soft tissue mass, but in the other 9 patients the condition of the ossicular reconstruction was well demonstrated. Prosthesis dislocation was apparent in 2 patients. We recommend HRCT examination in the follow-up of tympanoplasty patients.

Cholesteatoma↗