Ossicular Reconstruction Prosthesis Research Articles

Are postoperative hearing results better with titanium ossicular reconstruction prostheses?

Soler ZM, Smith TL. (2009) What is the Role of Long-Term Macrolide Therapy in the Treatment of Recalcitrant Chronic Rhinosinusitis? The Laryngoscope DOI: 10.1002/lary.20549. Morris LGT, Myssiorek D. (2009) When is Surgery Indicated for Asymptomatic Primary Hyperparathyroidism? The Laryngoscope DOI: 10.1002/lary.20560. Zeitler DM, Lalwani AK. (2009) Are Postoperative Hearing Results Better with Titanium Ossicular Reconstruction Prostheses? The Laryngoscope DOI: 10.1002/lary.20573. The above articles, published online July 1, 2009, have been retracted by agreement between the authors, the Journal Editor-in-Chief, Jonas Johnson, and John Wiley & Sons, Inc. These retractions have been agreed as the articles were incorrectly formatted for Early View publication and inaccurately represent The Triological Society's Trio BP article series. These articles will be reformatted for publication in the November issue of The Laryngoscope, and will be given new DOI numbers.

Experimental middle ear surgery in rabbits: a new approach for reconstructing the ossicular chain

This experimental animal study aimed at evaluating a new prosthesis to replace the ossicular chain; we developed a new technique for surgical implantation into the middle ear of rabbits. The rabbit middle ear is, owing to the relative anatomical dimensions involved, an ideal environment for implantation procedures involving the ossicles, as the surgical conditions are similar to those of the human middle ear. This study included a total of 34 approximately six-month-old female white rabbits (New Zealand) weighing between 3.2 and 4.4 kg. The implants used were constructed of ceramic materials (titania, TiO(2)) of various pore sizes. Directly prior to implanting the total ossicular reconstruction prostheses (TORPs), as well as at 28, 84 and 300 days after implantation, electric response audiometry was used to determine the hearing thresholds of the animals (bone conduction; click stimulus nHL). An erbium:YAG laser was used to excise the original ossicular chain. Following implantation, we were unable to detect any stenosis of the outer ear canal or perforation of the tympanic membrane. The conductive hearing threshold was in the range of 4.21 +/- 6.68 dB nHL (n = 131). The hearing level showed no significant difference before and after surgery (P < 0.05).

Ossiculoplasty with intact stapes: analysis of hearing results according to the middle ear risk index

Conclusions. In ossiculoplasty with intact stapes, using autologous incus, cortex bone chips and plastipore partial ossicular reconstruction prostheses, improvement in hearing was nearly equal. In patients who had mild risk scores, the incus had better gain values compared with patients who had severe scores. Objective. We aimed to prove the utility of the middle ear risk index score and its predictive value in hearing outcome. We also evaluated hearing results for different reconstruction materials. Patients and methods. This was a retrospective chart review of 189 patients who had ossiculoplasty with intact stapes using autologous incus, cortex bone chips and plastipore partial ossicular reconstruction prostheses. Hearing outcomes and the average improvement in hearing with different reconstruction materials were analysed by using middle ear risk index scores. Results. The average hearing improvements for incus, cortex and partial ossicular reconstruction prostheses were 12.77±14.58 (p<0.001), 12.34±15.98 (p=0.005) and 14.10±13.87 dB (p<0.001), respectively. The postoperative air–bone gap levels were 20.42±14.54 dB in incus, 17.33±16.86 dB in cortex and 17.59±11.66 dB in partial ossicular reconstruction prostheses. When the preoperative middle ear risk index scores and postoperative air–bone gap and gain values were compared, in the incus group, statistically significant associations were demonstrated between scores and hearing outcomes (p=0.009).

Kurz titanium prostheses in paediatric ossiculoplasty—Short term results

The objective of this study is to assess the efficacy of ossiculoplasty procedures in the paediatric population when the Kurz titanium ossicular prosthesis is used. Data was collected prospectively upon 14 ossiculoplasty cases using Kurz titanium prostheses. Audiological parameters using four frequency average (FFA(0.5, 1, 2 and 4kHz)) were assessed pre- and post-operatively. In the case of patients reconstructed using partial ossicular reconstruction prostheses, 7/9 (78%) achieved an air bone gap (<20dB) using FFA criteria. Parameters at 12-month follow-up suggested 4/5 (80%) patients reconstructed using total ossicular reconstruction prostheses achieved an air bone gap (<20dB) using FFA. The question of age and presence of co-existing cholesteatoma or tympanic membrane perforation does not appear to mitigate against performing ossicular reconstruction in this age group. Consequently, the results of this study suggest that the use of Kurz titanium prostheses is a feasible option to augment hearing in paediatric cases involving chronic otitis media. This is a significant finding especially in view of the added psychological burden of hearing difficulties carried by the paediatric population.

How does prosthesis head size affect vibration transmission in ossiculoplasty?

The transmission of vibrations from the tympanic membrane to the stapes footplate by an ossicular reconstruction prosthesis is affected by the size of the prosthesis head. We sought to determine if augmenting or reducing the head size of prosthesis had a systematic effect on transmission of vibrations to the stapes. We conducted a fresh cadaveric temporal bone middle ear study. The incus was replaced with a prosthesis using a tympanic membrane to stapes head (TASH)-type hydroxyapatite prosthesis in nine fresh cadaveric temporal bones. Three prosthesis head sizes were created: unaltered, reduced, and augmented. Stapes vibrations were measured with a laser Doppler vibrometer in response to acoustic frequency chirps at 90 dB SPL. All three head size prostheses resulted in smaller stapes vibrations than the intact ear. There was no difference in the vibration transmission between the three different head sizes. All prostheses showed a vibration loss of 10 to 15 dB compared to the intact ear. Within the range of sizes tested, prosthesis head size had little impact on vibration transmission to the stapes footplate.

Effect of Adhesion on the Acoustic Functioning of Partial Ossicular Replacement Prostheses in the Cadaveric Human Ear

Adhesion formation following ossiculoplasty surgery has been implicated as a cause of the progressive deterioration of an initially good postoperative hearing result. Scar tissue between the partial ossicular reconstruction prosthesis (PORP) and adjacent middle ear structures is a common finding at revision surgery. This study aims to investigate the effects of simulated scarring on the microacoustic transmission characteristics of a PORP in the fresh cadaveric human temporal bone. Cortical mastoidectomy and extended posterior tympanotomy permitted access to reflective markers placed on the stapes footplate. A sound stimulus at 80 to 95 dB was presented to the closed external ear canal and displacements were measured with the laser Doppler vibrometer. PORPs were placed in cadaveric specimens, and the shaft of the prosthesis was cemented to the adjacent promontory using dental cement. Serial measurements were made from the stapes footplate as the adhesive was allowed to harden, a process that we have taken to simulate the gradual fixation of the prosthesis by scarring in the live patient. There was a consistent reduction in stapes footplate displacement as the cement hardened. The gradual adhesion of a PORP to the promontory produces a consistent reduction in microacoustic transfer to the stapes footplate in the fresh human cadaveric model.

Management of congenital atresia of the external auditory canal.

The management of a unilateral congenital atresia of the external auditory canal is nonuniform and debated. Various surgical approaches, timing, coordination with microtia repair, and variable hearing improvements all contribute to the debate regarding management of this entity. This paper outlines our craniofacial team approach to the congenital unilateral atresia and microtia in children. Selection criteria, timing of repair, coordination with microtia repair, surgical results, and pitfalls will be discussed. The results of surgery in 16 patients with unilateral congenital atresia of the external auditory canal and 2 children with bilateral atresia will be presented. Repair of the atresia was undertaken in children 5 years or older who had pneumatized mastoids and middle ears. Replacement of the malleus/incus complex with a partial ossicular reconstruction prosthesis improved closure of the air-bone gap. Drawbacks included meatal stenosis and deepithelization of the split thickness skin graft lining the external auditory canal. Repair of the unilateral congenital atresia is a demanding and challenging problem but one in which excellent results are achievable.

Malleus-to-Footplate versus Malleus-to-Stapes-Head Ossicular Reconstruction Prostheses: Temporal Bone Pressure Gain Measurements and Clinical Audiological Data

Several clinical reports suggest that if the stapes superstructure is intact, ossicular reconstruction should be made to the stapes head rather than the footplate to achieve a better hearing outcome. To test this hypothesis, we compared the in situ mechanical performance of hydroxylapatite (HA) malleus-to-stapes-head (MSH) ossicular reconstruction prosthesis (ORP) with malleus-to-footplate (MFP) ORP, both manufactured by Project HEAR. ORPs are commonly used to replace a missing or deficient incus. However, hearing outcomes are highly variable, depending on the ORP material, design, surgical technique, and ORP positioning. Cochleo-vestibular pressure measurements in human cadaveric temporal bones for the HA MFP ORP have been reported by Puria et al. (2005). In the present study, the ear canal pressure Pe and cochleovestibular pressure Pv were measured in cadaveric temporal bones with intact incus, removed incus, and MSH ORP reconstruction. The relative loss in gain, Lmsh, is defined as the ratio of Pv with reconstructed MSH ORP to intact incus and compared with Lmfp. A retrospective clinical audit of the pre- and postoperative audiologic results of patients who had undergone ossiculoplasty with either MSH or MFP ORP was conducted for comparison. For the 0.5 to 3 kHz frequency range, Lmsh magnitude is 6.2 dB lower than the Lmfp magnitude (p = 0.05). The retrospective audit of audiologic results after ossiculoplasty with either MSH or MFP ORP revealed a similar difference in gain between the two ORP designs with air-bone gap differences of 7.6 dB (p = 0.04) and air conduction threshold differences of 8.0 dB (p = 0.13) for these patients. The MFP ORP showed better average pressure gain compared with the MSH ORP across the speech frequencies. Surgeons performing ossiculoplasty with designs similar to Project HEAR HA ORPs, where there is direct columella-like connection between the malleus and stapes, should consider using the MFP ORP design to achieve a better postoperative audiologic result, even when the stapes superstructure is intact.

How do cartilage and other material overlay over a prosthesis affect its vibration transmission properties in ossiculoplasty?

Objective The prosthesis/eardrum interface is often deliberately modified by cartilage overlay, or by soft tissue in-growth. We examined the effects of vibration transmission to the footplate of inserting cartilage of varying sizes, and materials of varying rigidities. Study design and setting Using fresh human cadaveric temporal bones, stapes vibrations were measured. A partial ossicular reconstruction prosthesis was covered with differing materials and cartilage sizes. Materials used included glass (rigid), cartilage (intermediate), and Merocel® (soft). Cartilage sizes varied in size relative to the prosthesis head. Results Rigidity of material had little impact. Cartilage size had an impact, with smaller cartilage covers performing best. Conclusion Larger cartilage sizes performed worse. This could be a result of increased tension on the eardrum from larger cartilage size. There is little impact stiffness of interposed material stiffness. Significance Cartilage of the size used clinically has little impact on vibration transmission to the footplate. A wide range of materials could clinically be interposed over the prosthesis.

Ossiculoplasty with total hydroxylapatite prostheses anatomical and functional outcomes.

To evaluate the results of partial and total ossicular reconstruction prostheses entirely made of hydroxylapatite. A retrospective review of cases followed-up between 1997 and 2000. Tertiary referral center. One hundred adult patients (60 men and 40 women) were studied. The mean age was 55 years (range, 25 to 65 years). Fifty patients had a previous tympanoplasty. The series included 45 cholesteatomas (45%), 37 chronic otitis media without cholesteatoma (37%), 13 retraction pockets (13%), and 5 posttraumatic ossicular displacements (5%). A one-stage ossiculoplasty with a partial ossicular reconstruction prosthesis (n = 65) or a total ossicular reconstruction prosthesis (n = 35) was performed. This was associated with a simple mastoidectomy in 70 cases and a radical mastoidectomy in 10 cases. All patients were followed-up at 1 year, and 50 were reexamined 2 years after surgery. Clinical and audiometric data were collected in a database at each visit. A prosthetic extrusion was noted in two cases (2%). A prosthetic displacement occurred in 10 cases (10%). A revision surgery was carried out in 10 cases because of an ossiculoplasty failure or a disease recurrence. At 1 year, the residual air-bone gap was lower in cases with a partial ossicular reconstruction prosthesis than those with a total ossicular reconstruction prosthesis (16 +/- 9.3 versus 23 +/- 13.7 dB, p < 0.05). The gain in mean air conduction threshold was 21 +/- 12.8 dB in cases of partial ossicular reconstruction prosthesis and 19 +/- 11.3 dB in cases of total ossicular reconstruction prosthesis (not significant). Revision surgery, canal wall-down mastoidectomy, or cholesteatoma yielded poorer functional results. Partial ossicular reconstruction prosthesis and total ossicular reconstruction prosthesis entirely made of dense hydroxylapatite yielded high rates of air-bone gap reduction and high anatomic stability.

Wie verhalten sich metallhaltige Mittelohrimplantate in der Kernspintomographie?

Magnetic resonance imaging (MRI) has gained in frequency and importance as a diagnostic procedure. In respect to the close anatomical relationship in the temporal bone it is necessary to know whether it is hazardous to patients with metallic middle ear implants regarding displacement and rise in temperature. For the MR image quality artefacts caused by metallic prostheses should be low. Four different stapes prostheses made from titanium, gold, teflon/platinum and teflon/steel, a titanium total ossicular reconstruction prosthesis (TORP) and two ventilation tubes (made from titanium and gold) were tested in a 1.5 Tesla MRI machine regarding their displacement. All objects were first placed in a petri dish, then suspended from a thread and finally immersed in a dish filled with Gadolinium. Temperature changes of the implants were recorded by a pyrometer. None of the implants moved when they were placed in the petri dish or suspended from the thread. On the water surface the teflon/platinum and the teflon/steel pistons adjusted their direction with their axis longitudinally to the MRI scanner opening and the teflon/steel piston floated towards the MRI-machine when put close enough to the scanner opening. No rise in temperature was recorded. All implants showed as little artefacts that would still make an evaluation of the surrounding tissue possible. Patients with any of the metallic middle ear implants that were examined in this study may undergo MRI-investigations without significant adverse effects.

Morphological and functional results of Palisade Cartilage Tympanoplasty

The application of cartilage in tympanoplasty has been generally accepted, because cartilage as a bradytrophic tissue allows stable and functionally reliable reconstruction of the eardrum even in difficult pathological conditions (such as subtotal defects, tympanosclerosis etc.). A special surgical technique using small cartilaginous chips for the reconstruction of the eardrum has been developed by J. Heermann, who introduced it as Palisade Cartilage Tympanoplasty (PCT). Although being increasingly applied in otosurgery, this technique has to date neither been evaluated regarding morphological and hearing results nor regarding its combination with titanium ossicular reconstruction prostheses. Therefore we reviewed 84 of 94 ears (92 patients, 58 female, 34 male) 12 to 36 months after PCT. A recurrent defect was seen in 2 ears (1 adhesive otitis, 1 subtotal defect). There were no extrusions of prostheses. Preoperatively an ear-bone-gap of 0-10 dB was seen in 2 ears, 11-30 dB in 48 and 31-59 dB in 34 ears. Postoperatively the corresponding numbers were 25, 50 and 9 ears. The low rate of recurrent tympanic membrane defects (2.4%) shows that palisade cartilage tympanoplasty is particularly appropriate for the management of difficult indications in middle ear surgery. Further, it could be demonstrated that the PCT can be combined safely with titanium ossicular reconstruction prostheses. Regarding postoperative hearing results the negative preselection of pathological conditions has to be considered.

Management of congenital atresia of the external auditory canal

The management of a unilateral congenital atresia of the external auditory canal is nonuniform and debated. Various surgical approaches, timing, coordination with microtia repair, and variable hearing improvements all contribute to the debate regarding management of this entity. This paper outlines our craniofacial team approach to the congenital unilateral atresia and microtia in children. Selection criteria, timing of repair, coordination with microtia repair, surgical results, and pitfalls will be discussed. The results of surgery in 16 patients with unilateral congenital atresia of the external auditory canal and 2 children with bilateral atresia will be presented. Repair of the atresia was undertaken in children 5 years or older who had pneumatized mastoids and middle ears. Replacement of the malleus/incus complex with a partial ossicular reconstruction prosthesis improved closure of the air-bone gap. Drawbacks included meatal stenosis and deepithelization of the split thickness skin graft lining the external auditory canal. Repair of the unilateral congenital atresia is a demanding and challenging problem but one in which excellent results are achievable. (Otolaryngol Head Neck Surg 1997;116:580-4.)

Congenital Absence of the Oval Window

From 1983 to 1987, seven patients with conductive hearing loss were found to have congenital absence of the oval window. Six of these patients underwent vestibulotomies and reconstruction with House wires or total ossicular reconstruction prostheses. Surgical findings included absent or rudimentary stapes in all cases, abnormal facial nerves in four cases, and abnormal long processes of the incus in four cases. All patients had normal external ear canals and tympanic membranes. Hearing initially improved 20 to 45 dB in four of the six patients reconstructed. Over time, however, much of this initial hearing gain was lost. A marked difference in hearing results was evident between this series of absent oval window cases and a recent series of major atresia cases.

Congenital absence of the oval window

From 1983 to 1987, seven patients with conductive hearing loss were found to have congenital absence of the oval window. Six of these patients underwent vestibulotomies and reconstruction with House wires or total ossicular reconstruction prostheses. Surgical findings included absent or rudimentary stapes in all cases, abnormal facial nerves in four cases, and abnormal long processes of the incus in four cases. All patients had normal external ear canals and tympanic membranes. Hearing initially improved 20 to 45 dB in four of the six patients reconstructed. Over time, however, much of this initial hearing gain was lost. A marked difference in hearing results was evident between this series of absent oval window cases and a recent series of major atresia cases.