Titanium Piston Research Articles

Impact of manual crimping on stapedotomy outcomes.

The impact of tight stapes crimping on hearing is a matter of debate. Several studies postulate that tight crimping is essential for lifelong success, whereas others have debated whether firm attachment leads to incus necrosis. Several types of prostheses with different coupling mechanisms have been developed, and manual crimping remains the most frequently used technique. This study investigates whether tightness really does affect hearing outcome. The hearing results of patients who underwent primary stapedotomies using three different titanium pistons were analysed. The surgeons categorised the firmness of the piston attachment into 'tight' and 'loose' crimping groups. Hearing outcome and reasons for revision surgical procedures were investigated. The mean post-operative air-bone gap for frequencies of 0.5-4 kHz was 8.80 dB for the tight crimping group (n = 308) and 9.55 dB for the loose crimping group (n = 39). No significant difference was found (p = 0.4650). Findings at revision procedures were comparable (1.6 per cent vs 5 per cent). Although firm crimping is strongly advised, a movable loop upon palpation does not lead to unsatisfactory hearing results, and does not mandate piston replacement or bone cement use.

An experimental and thermodynamic study of sphalerite solubility in chloride-bearing fluids at 300–450 °C, 500 bar: implications for zinc transport in seafloor hydrothermal systems

The solubility and speciation of zinc (Zn) in chloride-bearing aqueous fluids at high temperature and pressure are important for understanding Zn transport in natural hydrothermal systems and associated mineralizing processes. Here, we measured sphalerite solubility in NaCl-HCl-H2O fluids using a fixed-volume titanium alloy hydrothermal reactor equipped with a newly designed gas-tight titanium piston sampler. This novel reactor-sampling system is capable of acquiring internally filtered fluids at high temperature and pressure. The experiments were conducted at 300–450 °C, 500 bar, in fluid with 0.5 m and 1 m NaCl, respectively. The measured sphalerite solubilities are consistent with predicted values using previous thermodynamic data at 300–400 °C, but diverge significantly above 400 °C. To resolve this discrepancy, we adjusted the solubility product of Zn minerals by modifying the heat capacity and Born coefficients that describe the Gibbs Free Energy of formation from the elements of the Zn2+ aqua ion based on the new solubility data. The refined Helgeson-Kirkham-Flowers (HKF) equation of state (EoS) of Zn2+ empirically reproduces the solubility data of Zn minerals from previous experimental studies well over the covered T-P range (25–600 °C, Psat to 2 kbar), but extends accurate predictions to conditions typical of deep sea hydrothermal systems, down to fluid densities of 0.35 g/cm3. Thermodynamic modelling using the revised EoS of Zn2+ shows that higher temperatures, chlorinity and lower pH increase Zn solubility, and that Zn chloride complexes are the predominant species. The influence from salinity on Zn solubility is less significant in fluids with low pH. Applied to seafloor hydrothermal systems, our results suggest that in addition to temperature, pH and total dissolved chloride, fluid/rock ratio may be an important factor contributing to Zn concentrations in vent fluids at Mid Ocean Ridges.

To compare the efficacy of Titanium versus Teflon piston on hearing outcome in terms of Air conduction gain and Air Bone Gap closure in LASER Stapedotomy – A retrospective study

Aim: To determine the efficacy of Titanium versus Teflon piston on hearing outcome in terms of Air Conduction Threshold (ACT) gain and Air Bone Gap (ABG) closure in patients undergoing LASER Stapedotomy. Methods: This retrospective study was conducted at the department of ENT and Head and Neck Surgery, AIIMS Patna. 40 patients underwent LASER stapedotomy. Both Teflon (0.4mm and 0.6mm D, Grace Medical Devices) and Titanium (0.4mm D, Kurz Medical Devices) pistons were inserted randomly. Crimping of titanium Kurz piston was not required due to its unique design which fits on to the incus long process like a clip whereas all the Teflon pistons required crimping.Titanium (Kurz Medical Devices) pistons are costlier in comparison to Teflon (Grace Medical Devices) pistons. Preoperative and 3 monthly postoperative Pure Tone Audiograms (PTA) wereobtained. ACT (Air conduction threshold) gain and ABG (Air Bone Gap) closure were measured.Data was analyzed with IBM SPSS Statistics software Version 20. Descriptive analysis,paired and unpaired t-tests were applied. P-value of <0.05 at 95% confidence levels was considered statistically significant. Results: 40 patients (M: F: 3:7) underwent LASER stapedotomy.Titanium piston was utilized in 11and Teflon in 29 patients. Patients with titanium piston experienced a mean ACT gain of 21.51±05.42dBand mean ABG closure of 12.27±05.18 dB. Those with Teflon piston gained a meanACT gain of 18.54±04.43 dB and mean ABG closure of11.96±06.12 dB.Both groups experienced statistically significant hearing gain (p <0.05).Both groups were however comparable and the difference between these parameters was statistically insignificant (p>0.05).Conclusion: Both titanium and Teflon pistons are equally efficacious in improving postoperative hearing gain in LASER stapedotomy patients in terms of ACT gain and ABG closure. Titanium Kurz pistons do not require crimping making it easier to use in comparison to the Teflon pistons which needs to be crimped every time though cost may be a limiting factor in the usage of Titanium pistons.Both types of pistons can be satisfactorily employed in this surgical procedure if we consider the hearing gain post operatively. Study design: A retrospective observational study Keywords: Otosclerosis, Teflon, Titanium, Air Conduction Threshold (ACT), Air Bone Gap (ABG) closure

Comparative study between Teflon and Robinson stainless steel Prostheses in ototsclerosis surgery

BACKGROUND: The main cause of conductive hearing loss in the presence of a completely normal tympanic membrane is otosclerosis. There are different types of prostheses that could be used in the operation with different materials, designs, and shapes. The prostheses utilized in this study including both Teflon and Robinson are assessed. The aim of our work is to match and determine the surgical steps, postoperative results, and surgical complications of both Teflon piston and Robinson titanium prosthesis in line with the improvement in hearing and therefore the ability to decrease the air-bone gap.Results: stapedotomy done for 40 patients with Teflon piston and Robinson stainless steel piston prosthesis, 20 patients for each type. Both groups were matched based on age and preoperative bone-conduction scores. Follow up for all patients were done up to 6 months postoperatively. We have excluded all revision cases. A comparison between both prostheses was assessed by differences in the Air Bone (AB) Gap and surgical difficulties and complications. Both groups showed no significant difference either in hearing improvement or postoperative decrease of an air-bone gap. The Robison titanium piston needs more surgical skills than Teflon one. Both groups had no surgical complications.Conclusions: There is an equal benefit to patients with the use either of Teflon piston or Robinson protheses and there is no statistically significant difference between both of them. We need a long time of follow up the results to be analyzed.Keywords: Teflon prosthesis, Robinson prostheses, otosclerosis, stapedectomy.

Titanium and Platinum-Fluoroplastic Stapes Prostheses Visualization on Cone Beam Computed Tomography and High-Resolution Computed Tomography.

Objective: The aim of this study was to evaluate whether stapes prostheses can be visualized with less metal artifacts and therefore more accurately on cone beam computed tomography in comparison to computed tomography imaging. Recent studies have shown that cone beam computed tomography has advantages when imaging metal artifacts. Patients with hearing loss or vertigo, who have undergone stapedotomy, often present a challenge for otologic surgeons. Imaging studies can deliver crucial additional information. Methods: A retrospective analysis of imaging studies and clinical data in a tertiary care center were carried out. Forty-one patients with forty-five implanted ears were evaluated in the study. All included patients had been implanted with a platinum–fluoroplastic (n = 19) or titanium (n = 26) piston and subsequently had undergone imaging months or years after surgery for various reasons. Patients underwent computed tomography or cone beam computed tomography of the temporal bone depending on availability. Piston visualization, prosthesis length, vestibular intrusion and audiologic results were compared between the groups. Piston position on imaging studies were compared to intraoperative findings. Results: Functional length measurements of all prostheses were carried out with a mean error of −0.17 mm (±0.20). Platinum–fluoroplastic protheses were significantly underestimated in length compared to titanium prostheses. To analyze the material-dependent difference in the measurement errors of the imaging techniques the interaction was tested in an ANOVA model and showed no statistically significant result (p = 0.24). The blinded neuroradiologist viewed two implants, both platinum–fluoroplastic pistons, as located outside of the vestibule due to an underestimation of the prothesis length and the missing radiodensity of the lower end of the prosthesis. Conclusion: Surgeons and radiologists should be aware of the different types and radiologic features of stapes prostheses and the missing radiodensity of some protheses parts. Cone beam computed tomography is an imaging alternative with a potential advantage of reduced radiation in patients after stapes surgery suffering from vertigo or hearing loss to evaluate piston position.

Teflon implants vs titanium implants in stapedotomy - A comparative study

Objective: This study compares two types of implants- a Teflon piston and a titanium piston, used in stapes surgery for otosclerosis. Study Design: A non-randomised prospective study conducted on 40 patients, in 2 groups of 20 each, undergoing stapedotomy in a tertiary care hospital. Pure tone audiometry results were noted preoperatively and 3 weeks post-operatively.Results: Both Teflon and titanium prostheses provided almost equal benefits to patients in terms of Air-Bone gap closure.Conclusion: While there is statistically no significant difference in the results observed, surgical skill of the operating surgeon plays an important role in hearing improvement and long-term results would require long term evaluation.

Sulfidation of Electrospun Vanadium Oxide Fiber Mats for Lithium-Ion Battery Electrodes

Energy storage plays a fundamental part in fulfilling the necessity of a more efficient, renewable, and environmentally friendly energy supply chain. Lithium-ion batteries are currently the most widely portable storage devices and typically employ transition metal oxides or dichalcogenides as electrode materials that promote redox reactions with lithium ions by either insertion or conversion mechanisms. For the latter, metal sulfides are prominent electrode materials owing to their high electrical conductivity and redox reversibility and high specific capacity. Vanadium sulfides exist in a range of crystal structures that can promote insertion of different ions in both anode and cathode side. Besides, they can also take part in conversion mechanisms in lithium-sulfur batteries. However, slow diffusion of lithium ions through the structure and high volumetric expansion compromises the average performance and stability of these materials. One strategy commonly adopted is the synthesis of hybrid nanostructured particles that combine a large surface area with short ion and electron transport pathways. The presence of conductive carbon in the hybrid material constrains the material expansion and ensures a conductive network during the conversion mechanism. Compared to other synthetic approaches, electrospinning enables the production of fibers constituted of nanosized structured materials. The continuous network of fibers forms free-standing mats that can be directly used as electrodes with no post-processing, coating or binder additives. Such mats allow continuous electron transport across the material while the synthesis itself promotes the homogeneous distribution of the components along the fibers, preventing particle agglomeration. In this work, vanadium oxide (VOx) mats are produced by electrospinning and converted to vanadium sulfide by thermal sulfidation process. The VOx fibers were prepared by the previously optimized electrospinning process.[1] The fiber mats were thermally treated under H2S/Ar atmosphere in different conditions to convert VOx into VSx. Lower synthesis temperatures promote a high degree of conversion while keeping smaller VSx domain size,and a higher interfacial contact between the carbon and the VSx phase. The VSx/C hybrid mats were directly applied as Li-ion battery electrodes and tested in different potential ranges to evaluate conversion and insertion mechanisms. The electrodes were paired with Li-ion discs in standard LP30 electrolyte using custom-built cell using spring-loaded titanium pistons.[2] The different VSx fibers were tested regarding redox profile, rate handling, and cycle stability. For the fibers with smaller VSx domain size, capacities up to 900 mAh/g were achieved when evaluating the whole active potential window, yet rate handling was compromised. When restricted to intercalation side capacities ranging of 150-280 mAh/g were observed, with good rate handling up to 2 A/g and full recovery of the initial capacity.

Malleostapedotomy with the self-fixing and articulated titanium piston

ObjectiveTo analyze the results of malleostapedotomy performed by applying the self-fixing and articulated titanium piston according to Häusler.Study designRetrospective case review.SettingTertiary referral center.Patients and interventionsThis study concerns a retrospective analysis of the results of malleostapedotomy with the use of a self-fixing articulated titanium piston in 16 ears of 16 consecutively treated patients between 2005 and 2009. The medical files were used for the acquisition of data on medical and surgical history and to obtain pre- and postoperative audiometry. Diagnosis and outcomes of mainly revision surgeries are presented and compared to the literature.Main outcome measuresEffect of (revision) malleostapedotomy by evaluating postoperative audiometry and air–bone gap closure.ResultsThe postoperative air–bone gap closure was ≤ 10 dB in 9/16 (56%) ears and within ≤ 20 dB in 13/16 (81%) ears. The mean postoperative air–bone gap was 14.3 dB HL (0.5–2.0 kHz) and 17.3 dB HL (0.5–4.0 kHz). Postoperatively, there was no increase in bone conduction thresholds larger than 3 dB (0.5–2.0 kHz) and postoperative dizziness was absent or very limited and transient.ConclusionsThe malleostapedotomy procedure has become surgically less demanding over time by the technical improvements present in the nowadays available pistons. The design of the self-fixing and articulated titanium piston used in the present group of patients allows a safe and straight-forward malleostapedotomy procedure. Present hearing outcomes match with results presented in the literature.

MPR-CT Imaging for Stapes Prosthesis: Accuracy and Clinical Significance.

The aims of this article are: 1) to re-evaluate the accuracy of multiple planar reconstruction computed tomography (MPR-CT) imaging on stapes-prosthesis parameters, and 2) to clarify possible relationships between prosthesis intravestibular depth and postoperative hearing outcomes. Seventy patients (46 women and 24 men; 32 right and 38 left sides) with the mean age of 40 years (range, 19-62 yr) with clinical otosclerosis. All patients underwent stapedotomy and were implanted with the same type of titanium piston prosthesis by the same surgeon. Postoperative MPR-CTs were obtained at patients' follow-up visits. The length and intravestibular depth of the stapes prosthesis (including absolute and relative depth) were calculated from the MPR-CT imaging. Relationships between the intravestibular depth of the prosthesis and hearing outcomes (pre- and postoperative audiograms) were analyzed using Spearman correlation analyses. The length of the prosthesis was overestimated by 1.8% (0.1 mm) by the MPR-CT imaging. Axial and coronal measurements were significantly correlated (p < 0.05). There was great intersubject variability in hearing outcomes differed insignificantly, regardless of intravestibular depth within the security range. No relationships were found between the intravestibular depth of the stapes prosthesis, as measured with MPR-CT, and postoperative hearing results. MPR-CT can provide an accurate estimation of stapes prosthesis parameters. However, the prosthesis intravestibular depth did not seem to affect postoperative hearing outcomes.

Teflon Implants Versus Titanium Implants in Stapes Surgery.

Otosclerosis is the most common cause of bilateral gradually progressive conductive hearing loss with normal tympanic membrane and Eustachian tube. Otosclerosis surgical treatment is one of the most gratifying operations in Otorhinolaryngology. It is not only the surgical techniques but also the prosthesis which are evolving in the attempt of providing best hearing results. Teflon piston is the most commonly employed prosthesis in stapes surgery. Titanium pistons are relatively the new development in the evolution of stapes prosthesis. The aim of this review article is to know and compare the surgical technicalities and postoperative outcomes including hearing improvement after the use of Teflon and titanium stapes piston. The adverse reactions occurred during follow-up were taken into consideration. The data in this article are supported by a Medline search. The use of both the prosthesis gave good results in cases of otosclerosis. The placement of titanium soft clip design was found easier than the earlier àWengen design of clip piston.

Ossiculoplasty with hydroxyapatite bone cement: our reconstruction philosophy

The main objective of this study is to analyze results obtained with hydroxyapatite bone cement (HABC) ossiculoplasties. This is a retrospective study of a case series. This study was conducted in an academic hospital and tertiary referral center. A total of 127 ossiculoplasties using HABC were evaluated. Ears were divided into three groups according to procedure: group 1 involved reinforcement of the incudostapedial joint with cement and reconstruction of an incus long process defect with cement. Group 2 involved partial ossicular reconstruction between the stapes and malleus handle with HABC. Group 3 was divided into two subgroups. Group 3B entailed reconstruction of the stapes with a mobile footplate (Austin-Kartush type B = group 3B) and group 3F with a fixed footplate (Austin-Kartush type F = group 3F) using a K-Helix piston (Grace Medical, Memphis, TN, USA) or a classical titanium piston (Kurz, Fuerth, Germany) glued to the incus remnant or malleus handle with cement. Anatomical and pre- and postoperative audiological results were assessed. The mean follow-up was 26 ± 14 months. Percentages of average postoperative air-bone gap ≤ 20 dB were 95, 82.5, 50 and 83.3%, and for air-bone gap ≤ 1 0 dB, 80, 50.9, 16.6 and 50% for groups 1, 2, 3B and 3F, respectively. No complications related to the cement or extrusion occurred. Hearing outcomes also remained stable over time. In our experience, ossiculoplasty with cement provides good and stable functional results, is safe, cost effective, and easy to use. HABC with or without biocompatible ossicular prostheses allows repair of different types of ossicular defects with preservation of the anatomical and physiological ossicular chain, as well as improved stability. Reconstruction of the incus long process or incudostapedial joint defect with cement is preferred over partial ossicular reconstruction.

Classic and reversal steps stapedotomy performed with CO2 laser: a comparative analysis

The objective of this paper is to evaluate and compare hearing outcomes, intraoperative and postoperative complications and tinnitus characteristics, with particular regard to the effects of stapes surgery on the course of tinnitus. Two groups were evaluated: one group of patients were treated with classical stapedotomy and the second group was composed of patients who underwent reversal technique. Eighty-four patients aged between 22 and 62years with otosclerosis were divided into two groups: group 1 (n=49, 17 male, mean age 38, patients treated with classic stapedotomy) and group 2 (n=35, 13 male, mean age 40, patients treated with reversal stapedotomy). Classical and reversal stapedotomy techniques were performed using CO2 laser; self-crimping titanium piston prosthesis were positioned in patients treated with reversal stapedotomy and classical stapedotomy. Preoperative and postoperative audiometric evaluation using pure tone audiometry (air-bone gap (ABG), bone-conduction thresholds and air-conduction thresholds). Tinnitus handicap inventory (THI) scale and intraoperative/postoperative complications were assessed in both groups. Wilcoxon's test and Friedman's test followed by post hoc analysis were used. There were no statistically significant differences in ABG, air conduction, bone conduction, and THI score variations after surgery between the two groups. Complications in both groups were not significant, and different. In conclusion, reversal and classic stapedotomies performed with CO2 laser can be considered efficient, safe and reliable techniques considering the hearing outcomes and complications recorded.

From incus bypass to malleostapedotomy: technical improvements and results

To assess results of malleostapedotomy using a Fisch Storz titanium piston with at least 10 months' follow up. Using a prospective database, the indications, surgical technique, and pre- and post-operative audiometric data for 60 patients undergoing malleostapedotomy between 2002 and 2010 were evaluated. Diagnoses and primary and revision surgeries were compared with reference to the literature. Sixty endaural malleostapedotomies were performed, 28 as a primary intervention and 32 as revision surgery. In 68 per cent, the underlying pathology was otosclerosis. The most common reason for revision surgery (i.e. in 59 per cent) was prosthesis dysfunction. Overall, the mean air-bone gap (0.5-3 kHz) for the primary intervention and revision surgery groups was 9.4 and 11.3 dB, respectively; an air-bone gap of less than 20 dB was obtained in 100 and 81 per cent of patients, respectively. There was no significant audiological difference between the primary and revision surgeries groups, and no deafness. Malleostapedotomy shows comparable results to standard incus-stapedotomy and may be preferable in the presented situations.

Diagnostic Findings in Stapes Revision Surgery-A Retrospective of 26 Years

The aim of the study is to obtain a detailed overview of the revision findings after stapes operations and to draw conclusions on a stapes prosthesis that can be recommended. : Retrospective case series. Tertiary otologic referral center. Approximately 12,000 middle ear operations within a period of 26 years were evaluated. The findings of the revisions were classified into surgeon related, prosthesis related, and other causes. Three hundred forty-three stapes revisions were done. Many different prostheses were found: the most common were Schuknecht prostheses and Teflon platinum, gold, and titanium pistons. Polyethylene strut, Teflon wire pistons, Shea (Teflon) pistons, and other techniques, such as columella or malleovestibulopexy, were rarely found.There are specific findings correlating to certain prostheses: Schuknecht prostheses were too short in 50% of the revisions (surgeon related), Teflon platinum caused necrosis or arrosion of the long incudal process (prostheses related) in 69%, and gold caused reparative granuloma sometimes combined with necosis of the incus in 70% (prostheses related). There was no specific diagnostic finding with titanium pistons, neither surgeon nor material related. An analysis of revision findings over an extended observation period can enable middle-ear surgeons to improve their surgical techniques and to select the best suited prosthesis. Self-fabricated stapes prostheses (e.g., Schuknecht) do not conform to required quality standards and should not be used. GoPi, which is no longer available, and TPlPi showed prosthesis-related diagnostic findings. The titanium prostheses used by the authors have proven to be excellently compatible and can therefore be recommended as safe stapes prostheses.

Analysis of the accuracy of high-resolution computed tomography techniques for the measurement of stapes prostheses

Severe cochleovestibulopathy is a complication after stapes plasty and CT may be needed to assess intravestibular intrusion depth of the stapes piston. The accuracy of modern CT systems in this task has not been established. Stapes plasty was performed on six cadaver ears, and Soft CliP titanium pistons were inserted. Specimens were then examined using three different CT systems: single source 64-row, dual source 64-row and flat-panel computed tomography (FD-CT). Piston length, width and intravestibular intrusion were measured by four independent observers. Temporal bone dissection was then performed and vestibular piston intrusion measured microscopically. Piston dimensions were overestimated by all observers and CT systems. Intravestibular penetration as assessed by CT was consistently greater than the value found on cadaveric anatomical dissection. On average, the CT measurement of width was 0.176 mm (44%) greater, length 0.125 mm (6.25%) greater and intrusion 0.333 mm (39.2%) greater than the anatomical measurements. FD-CT showed better image quality and partly less bias in several measurements, but penetration depth was still variably overestimated. CT measurement consistently overestimated intravestibular piston dimensions and vestibular intrusion. Modern temporal bone imaging systems are not yet able to depict the stapes piston position with a sufficient degree of accuracy.

Titanium CliP Piston Versus Platinum-Ribbon Teflon Piston

To analyze if titanium material and a clip attachment to the incus offer a hearing result advantage over the traditional Teflon piston in stapes surgery. Retrospective chart review. Subspecialty private practice. One hundred seven ears in 97 consecutive patients who had primary stapes surgery during 2003 to 2005. The first 74 ears received either a Teflon 0.5- or 0.6-mm piston, and the last 33 received a titanium 0.6-mm piston. American Academy of Otolaryngology-Head and Neck Surgery guidelines, including 4-frequency pure-tone average air-bone gap and success rate (gap, 10 dB). Mean pure-tone average air-bone gap for the Teflon 0.6-mm piston (5.1 dB) was significantly smaller than for the titanium 0.6-mm piston (8.1 dB) and the Teflon 0.5-mm piston (7.5 dB). Success rate did not differ. Although labeled as 0.6-mm pistons, the Teflon piston diameter was 10% greater than the titanium piston. Results were comparable among devices when adjusted for true piston diameter. Results for the titanium piston were significantly better when the fenestra was no more than 0.05 mm larger than the piston diameter. Comparing 2 pistons designated 0.6 mm in diameter, the Teflon piston produced better hearing results than the titanium device. However, actual piston diameter differed between devices that contributed to the superior results with the larger Teflon piston. In addition, the titanium piston performed better with a small stapes fenestra diameter that suggests an advantage for titanium over Teflon in certain conditions. The clip design was problematic for a few patients.

An analysis of the air-bone gap closure obtained by a crimping and a non-crimping titanium stapes prosthesis in otosclerosis

Objective To evaluate the hearing results of stapes surgery with two different titanium stapes prostheses. A crimping and a non-crimping prosthesis. Methods Retrospective analyses were carried out on the pre- and postoperative hearing results obtained after 126 primary stapedotomies with two different prostheses in patients with otosclerosis. Sixty-three patients had a stapedotomy with a K-piston Titanium (No. 1006107) type and 63 patients received a CliP-piston àWengen Titanium (No. 1006807) type after stapedotomy. The results were compared according to mean audiometrical parameters. A Chi-square Test analysis (a contingency table) was performed with odds ratio to analyze this retrospective case-control study. Results The hearing results of both titanium stapes prostheses were comparable. There was no difference in the final hearing results between the two pistons studied. No statistically significant difference between the postoperative air-bone gap closures by the two titanium stapes prostheses studied could be demonstrated. Conclusions Because of the different properties of the two titanium piston studied (CliP-piston àWengen Titanium type, no crimping and K-piston Titanium crimping necessary) a difference in the closure of the air-bone gap could be suspected. This comparative study could not demonstrate a statistical better air-bone gap closure for one of the titanium pistons. Both stapes prostheses showed good results in reconstruction of the hearing loss due to otosclerosis.

Eliminating the Limitations of Manual Crimping in Stapes Surgery: Mid‐Term Results of 90 Patients in the Nitinol Stapes Piston Multicenter Trial

To present our mid-term results of our multicenter study using the Nitinol self-crimping stapes piston, focusing on the interindividual variations of postoperative air-bone gap closures (ABGC), postoperative hearing results, and postoperative recurrences of conductive hearing loss and to compare these findings with our pilot group of patients. Prospective, multicenter cohort study involving three academic tertiary care referral centers from Australia, Switzerland, and the United States. Ninety patients with otosclerosis undergoing laser-stapedotomy with the Nitinol stapes piston were matched to reference patients from our titanium piston database. The effects of the self-crimping Nitinol piston on the postoperative ABGC, the postoperative interindividual air-bone gap (ABG) variations, and the postoperative hearing results were investigated 3, 6, 12, 18, and 24 months postoperatively. These data were statistically compared with the results of the control patients in our titanium stapes piston database and the results of our previously published pilot study. The mean postoperative ABG and the interindividual variations of the postoperative ABG continue to be significantly smaller in the Nitinol group; the extent of ABGC now is significantly larger in the Nitinol piston group. The postoperative mid-term stability of ABGC was similar in both groups. No adverse reactions occurred during follow-up. Our mid-term results continue to show that the self-crimping shape memory alloy Nitinol stapes piston overcomes the limitations of manual malcrimping in stapedotomy, thus simplifying and optimizing the surgical procedure. This so far has allowed reliable, safe, and consistent ABGC in patients with otosclerosis.

The Learning Curve in Stapes Surgery and Its Implication to Training

To identify the stapedotomy learning curve of two U.K. otolaryngologists. A retrospective review of the outcome of first 100 stapedotomy operations by each surgeon. Included in the study was a postal survey of the incidence of stapes surgery by U.K. otolaryngologists. Two tertiary referral centers. All ears in which primary stapedotomy was performed for otosclerosis. Nonotosclerotic cases and malleus stapedotomy cases were excluded. One surgeon used the technique of small fenestra stapedotomy with either a Teflon-wire or titanium piston but without vein graft interposition, whereas the second used the technique of stapedotomy with vein graft interposition and a Teflon piston. A moving average with a window of 15 dB was used to plot learning curves for the postoperative air-bone gaps. Using a postoperative air-bone gap of 20 dB or better as a definition of 'success,' the success rates with the increase in surgical experience of both surgeons were plotted on graphs, the learning curves. The end point of the learning curve was defined as the point where the curve reached its peak, and the results were sustainable. There was no clear-cut end point in both learning curves, although it appears that there is a landmark point at 60 to 80 cases for both surgeons. Both surgeons also had one "dead ear" in their first 15 cases. The postal survey showed that some trainers only performed small numbers of stapes surgery, whereas some otolaryngologists who performed stapedotomies regularly were not trainers. The study supports a learning curve in stapes surgery. To maximize the training opportunity of trainee surgeons, it may be advisable for learning centers to form network to provide target training for the trainee who has demonstrated the necessary dexterity and temperament of an otologist.

Comparison of Titanium and Robinson Stainless Steel Stapes Piston Prostheses

Although stainless steel stapes prostheses have generally been considered magnetic resonance imaging safe, there is concern that this may change with the development of more powerful imaging systems. The objective of the study was to determine whether a titanium piston stapes prosthesis would be audiometrically and surgically equivalent to a Robinson stainless steel piston for stapedectomy. Retrospective chart review. Private otology practice. In all, 50 patients underwent stapedectomy with a Gyrus titanium piston prosthesis. These patients were matched on the basis of age and preoperative bone-conduction scores with patients who underwent stapedectomy with a Robinson stainless steel piston prosthesis. Audiometric results are analyzed, and surgical complications noted. There was no significant difference between groups in hearing improvement or postoperative air-bone gap. The mean four-frequency hearing improvement was 27.7 dB for the stainless steel group and 27.8 dB for the titanium group. The mean postoperative air-bone gap was 2.65 dB for the stainless steel group and 2.60 for the titanium group. Neither group had a surgical complication. The titanium stapes prosthesis is a good alternative to a stainless steel prosthesis.