听骨赝复物临床设计与疗效评价现状

随着耳显微外科的发展 ,鼓室成形术逐渐推广 ,对听骨赝复物的研究亦逐步深入 ,以高分子合成材料、生物陶瓷、金属为代表的人工合成材料被广泛应用于听骨赝复物的制作。现就人工合成听骨赝复物的临床设计及疗效评价现状综述如下。1　听骨赝复物的设计1 .1 　 形态设计从解剖观点看 ,听骨赝复物的设计必须基于鼓室解剖结构 ,听骨赝复物的形态、大小是重建中耳传音功能的基础。人工合成听骨赝复物可分为全听骨赝复物 (TORP)和部分听骨赝复物 (PORP) ,TORP用于镫骨上结构或整个镫骨缺失者 ,PORP用于锤骨和砧骨有缺失而镫骨上结构完整者。…     

不同类型先天性中耳畸形的手术治疗

探讨先天性中耳畸形的临床分型及其手术策略。方法选取2016年6月—2019年12月收治的23例（33耳）先天性中耳畸形患者进行中耳畸形临床分型及不同的手术策略进行回顾分析，观察术后疗效和听力的恢复情况。术前对23例（33耳）中耳畸形患者均行耳内镜检查、听力学检查及颞骨CT并听骨链三维重建检查。结果23例患者中18例为术前明确畸形，5例为术中探查发现畸形。其中15例为锤、砧骨畸形，选择人工听骨赝复物（TORP或PORP）或自体听骨植入修复；6例为镫骨畸形，选择人工镫骨赝复物（Piston）植入；1例为鼓膜穿孔伴有先天性中耳畸形，先行鼓膜成形术，二期行听骨链重建手术；1例畸形程度比较复杂，面神经走形异常，在前庭窗处分叉，遮挡前庭窗，未能行进一步治疗。术后气导阈值提高至正常的有15例（65.2%）；骨气导差（ABG）恢复至30 dB以内的有16例（69.6%），ABG术后仍超过30 dB的有5例（21.7%），1例听力未改善（4.3%），1例无法行听骨重建（4.3%）。结论先天性中耳畸形术前诊断比较困难，CT检查很难精确评估，手术探查为最有说服力的诊断标准，明确中耳畸形临床分型后选择最佳的手术方式，是治愈疾病并提高患者术后听力最佳选择。     

全听骨赝复物和镫骨内面的机械力学

中耳重建术的效果可有很大差异。Austin,Shea,以及Fisch所设计的全听骨赝复物在顶盖的形状、顶盖与赝复物小柱相接的位置上,均有不同变化,但对赝复物放置于镫骨底板或卵圆窗上的位置则很少注意。通过对中耳解剖学和物理学复习,认为使全听骨赝复物的机械力学适合于镫骨底板是非常重要的。在正常声级的声刺激时,镫骨以后韧带为枢纽,自前向后有效地摆动。因此,有效的全听骨赝复物应使赝复物底板的接触能仿效这种运动。它将决定通过全听骨赝复物和镫骨内面的机械效率。     

自体皮质骨加引导组织再生胶原膜在鼓室成形术的应用

慢性化脓性中耳炎作听骨链重建术的方法众多 ,效果取决于多种因素。长期以来 ,人们致力于研究和制备人工听骨 ,作为听骨链赝复物的材料。其中 ,自体皮质骨赝复物存在被吸收降解的问题困扰着临床的应用。 1 995年以来 ,我们应用自体皮质骨加引导组织再生胶原膜 ,制成部分听骨赝复物(partial ossicular replacement prosthesis,PORP)及全听骨赝复物 (total ossicular replacementprosthesis,TORP) ,经临床应用 ,取得满意效果 ,并且在解决防止吸收问题上有了明显的进步。报告如下。1　资料和方法1 .1 　 临床资料50例 (耳 )慢性化脓性中耳…     

鼓室硬化手术治疗进展

鼓室硬化系中耳慢性炎症后遗的黏膜或黏骨膜退行性病变,是引起传导性聋的一种常见原因。早期对鼓室硬化是否采用手术治疗存在争议,但近年来随着鼓室成形术的广泛开展,特别是人工听骨赝复物中部分听骨赝复物(partial os-sicular replacement prosthesis,PORP)和全部听骨赝复物(t     

听骨赝复体

自20世纪50年代开展中耳传音结构重建以来，人们对听骨赝复体材料和构形进行了大量的实践和探索，这一直是耳显微外科领域研究的热点。     

生物玻璃中耳赝复物的初步报告

本文论述了新近可用于中耳重建术的材料及其进展,和应用生物玻璃作中耳赝复物的初步临床结果。该赝复物是由一种生物活性透明玻璃构成,是一种能与活体组织相粘合的材料。生物玻璃在小鼠的耳模型中已显示出它对听骨、软骨以及鼓膜软组织的结合力,植人物将完全由一层菲薄的被膜覆盖,仅有1～2根胶原纤维厚度,覆以无明显炎症且外观正常的中耳粘     

人工听骨植入前后听力学分析及相关因素研究

目的 对比观察传导性耳聋患者采用人工听骨行听骨链重建手术前后的听力学改变,并对影响听力提高的相关因素进行分析探讨。方法 采用人工听骨赝复物重建听骨链行鼓室成形术46例。植入人工听骨材料分别采用美敦力多孔聚乙烯听骨赝复物或德国宾格产钛质人工听骨。赝复体的高度为所测量的镫骨头与锤骨柄之间的距离,应用全听骨赝复物(TORP)时,则为所测得的镫骨底板与锤骨柄之间的距离。鼓膜修补材料取耳屏软骨膜或颞肌筋膜片,分别采用夹层法、外置及内置方法进行修补。对比观察手术前后听力改善情况。结果 对施行该手术的患者进行随访6～67个月,所有患者鼓膜修补愈合良好,听力提高有效率78.7%,没有发生排异反应和病变复发。结论 应用人工听骨赝复物对传导性耳聋患者重建听骨链行鼓室成形术安全有效,术后听力显著提高,并可避免佩带助听器所带来的诸多不便。     

听骨链病变的修复-赝复体技术的发展

听骨链缺损是临床常见中耳疾病之一,由此引起杠杆运动与阻抗匹配功能的障碍,使声波不能正常传入内耳,造成传导性聋。通过鼓室重建和听骨置换方法可以有效地改善听力,听骨链重建手术即重建鼓膜-底板间的连接、恢复两窗间相位-压力差,目的是恢复听骨链解剖结构的完整性、活动度及稳定性。随着耳外科技术、材料科学与制作工艺的进步,在听骨链病变的修复与重建领域出现了许多令人瞩目的进展。听骨赝复体是听骨链重建的重要材料,目前其在生物相容性、结构适形性、解剖可塑性以及制作精细化等方面达到前所未有的水平。本文从听骨假体设计、赝复体材料的特性、赝复体演变等方面进行归纳总结,就听骨链病变的修复及听骨赝复体技术的研究进展进行综述,为临床提供参考。     

可调节钛金属部分听骨赝复物在II型鼓室成形术中的应用

目的探讨可调节部分钛听骨在II型鼓室成形术听力重建中的疗效。方法回顾分析95例慢性化脓性中耳炎患者（均为单耳发病），随机分为两组，实验组（47耳）：应用可调节钛金属部分听骨赝复物（PORP）行开放式乳突根治术+II型鼓室成形术；对照组（48耳）：应用固定型钛听骨PORP重建听骨链。术后所有患者均随访1年以上，术后3个月、1年时分别对比两组的手术前后听力变化（0.5、1、2、4 kHz）及有效率。结果①实验组中1耳钛听骨移位；1耳筋膜裂缝，纳入听力研究45耳。一期手术成功率为95.7%（45/47），对照组中2耳钛听骨移位、2耳筋膜裂缝，纳入听力研究44耳。一期手术成功率为91.7%（44/48）；②实验组与对照组比较，术后3个月气骨导差比较，差异具有统计学意义（P<0.05）；术后1年气骨导差比较，差异无统计学意义（P>0.05）；③实验组与对照组有效率比较，差异无统计学意义（P>0.05）。结论可调节钛听骨应用于听骨链重建有独特优越性，术后3个月听力恢复优于固定型钛听骨，为中耳传音材料提供新的选择。     

Comparison of the mechanical performance of ossiculoplasty using a prosthetic malleus-to-stapes head with a tympanic membrane-to-stapes head assembly in a human cadaveric middle ear model.

HYPOTHESIS: Ossiculoplasty using prosthetic reconstruction with a malleus assembly to the stapes head will result in better transmission of vibrations from the eardrum to the stapes footplate than reconstruction with a tympanic membrane assembly to the stapes head. Both types of reconstruction will be affected by tension of the prosthesis. BACKGROUND: Theories (and some clinical studies) that the shape of the normal tympanic membrane is important suggest that prosthetic reconstruction to the malleus performs better than reconstruction to the tympanic membrane. This has not been previously tested by directly measuring vibration responses in the human ear. Our previous work suggests that tympanic membrane assembly to the stapes head type prostheses performed best under low tension. This had not been previously tested for malleus assembly to the stapes head type prostheses. METHODS: Hydroxyapatite prostheses were used to reconstruct a missing incus defect in a fresh cadaveric human ear model. Two types of prostheses were used, one from the stapes head to the malleus (malleus assembly to the stapes head), the other from the stapes head to the tympanic membrane (tympanic membrane assembly to the stapes head). Stapes footplate center responses were measured using a laser Doppler vibrometer in response to calibrated acoustic frequency sweeps. RESULTS: Tension had a very significant effect on both types of prostheses in the lower frequencies. Loose tension was best overall. The malleus assembly to the stapes head type prostheses consistently performed better than the tympanic membrane assembly to the stapes head type prostheses when stratified for tension. CONCLUSION: Tension has a significant effect on prosthesis function. Malleus assembly to the stapes head type prostheses generally result in better transmission of vibrations to the stapes footplate than tympanic membrane assembly to the stapes head type prostheses.     

Standardized measurements of the sound transmission of middle ear implants using a mechanical middle ear model

Several ways to evaluate the sound transmission properties of middle ear implants are now established. Besides computer-based simulations using acoustic and electrical analog circuits or finite element analysis, measurements can be performed with temporal bone preparations. Experiments with these preparations consider various anatomical properties, but a large number of parameters influence the outcome of measurements. To facilitate standardized measurements, a mechanical middle ear model was developed that allows comparison of the transfer function of middle ear implants on defined conditions. The model approximates the impedances of the tympanic membrane and inner ear with the aid of thin, flexible membranes. The implants are fit between the membranes, and displacement at an artificial stapes footplate is measured with an optical probe. Fundamental influences on the sound transmission properties of nine different middle ear implants (total ossicular replacement prostheses) were examined. Although the material and shape were different, some of the prostheses revealed very similar transfer functions. The mass of the implant showed the largest influence on sound conduction. With a higher mass, the frequency area above approximately 1 kHz was found to be significantly deteriorated. The lightest implant used was 4 mg and showed the best overall results. These findings show that middle ear prostheses should be as light as possible for optimum high-frequency transmission. Received: 24 May 1998 / Accepted: 9 July 1998     

Optimum tension for partial ossicular replacement prosthesis reconstruction in the human middle ear

OBJECTIVE: Hearing results from ossiculoplasty are unpredictable. There are many potentially modifiable parameters. One parameter that has not been adequately investigated in the past is the effect of tension on the mechanical functioning of the prosthesis. Our goal was to investigate this parameter further, with the hypothesis that the mechanical functioning of partial ossicular replacement prostheses (PORP) from the stapes head to the eardrum will be affected by the tension that they are placed under. METHODS: Fresh temporal bones were used to reconstruct a missing incus defect with a PORP-type prosthesis. Three different lengths of PORP were used, and the stapes vibrations were measured with a laser Doppler vibrometer using a calibrated standard sound in the ear canal. Eight temporal bones were used. RESULTS: Tension had a very significant effect on stapes vibration. In general, loose prostheses resulted in the best overall vibration transmission. The effects were most marked at the lower frequencies. There was a slight advantage to tight prostheses in the higher frequencies, but much less than the decrement in lower frequencies with tight prostheses. CONCLUSION: In ossicular reconstruction, best stapes vibration results in our model are achieved by shorter prostheses, which result in lower tension.     

Effects of ossicular prosthesis mass and section of the stapes tendon on middle ear transmission

BACKGROUND: The effects of changing prosthesis mass on middle ear transmission have not been previously systematically studied. Neither has the effect of stapes tendon sectioning. These are important parameters that can be surgically varied. HYPOTHESIS: Because the middle ear is compliance dominated at low frequencies, prosthesis mass will affect transmission of higher frequencies in the middle ear. METHODS: Eight fresh cadaveric temporal bones, with the incus removed, were loaded with a replacement prosthesis from the tympanic membrane to the stapes head. Laser Doppler vibrometry was used to measure stapes footplate vibrations. Vibrations were measured in response to chirps from 250 to 8 kHz at 90 dB SPL in the ear canal. The unloaded prosthesis mass was approximately 16 mg. Loadings with masses of approximately 2, 12, and 30 mg were placed on the stem. Recordings were repeated after cutting the stapes tendon. RESULTS: Mass loading affected the higher frequencies only, with significant effects only above 4 kHz. There was little low-frequency effect. Stapes tendon section showed an improvement in the lower frequencies but did not reach statistical significance. CONCLUSIONS: Mass of prostheses affects mainly higher frequencies. There is no drop in lower frequencies from using lower masses, so lighter-mass prostheses may be preferred. Stapes tendon section does not have a detrimental effect on middle ear transmission after ossiculoplasty.     

Middle ear sound transmission: a field of early interest to Merle Lawrence

Merle Lawrence, together with his teacher, E.G. Wever, made early contributions to the problem of middle ear sound transmission. Experiments were mostly done in cats and studied the effects of stepwise destruction of the middle ear on cochlear input and the effects of changes in middle ear air pressure on sound transmission. Their experiments provided the first physiologic evidence that the origin of auditory distortion lies in the inner ear, not in the middle ear. Lawrence also demonstrated a dual innervation of the tensor tympani muscle. With the aid of newer instrumentation, the authors studied the effects of alterations of the middle ear cavity configuration, stepwise removal of the middle ear structures, restriction of ossicular mobility, and ossicular mass loading. Our experiments caused partial decoupling of the tympanic membrane and distortion of the axis ligaments, the apparent weak elements of the middle ear system in cats. The placement of the prosthesis along the mallear handle did not affect sound transmission, as long as the connection between malleus and prosthesis was made inflexible.     

Effect of middle ear fluid on sound transmission and auditory brainstem response in guinea pigs

Combined measurements of middle ear transfer function and auditory brainstem response (ABR) in live guinea pigs with middle ear effusion (MEE) are reported in this paper. The MEE model was created by injecting saline into the middle ear cavity. Vibrations of the tympanic membrane (TM), the tip of the incus, and the round window membrane (RWM) were measured with a laser vibrometer at frequencies of 0.2-40?kHz when the middle ear fluid increased from 0 to 0.2?ml (i.e., full fill of the cavity). The click and pure tone ABRs were recorded as the middle ear fluid increased. Fluid introduction reduced mobility of the TM, incus and RWM mainly at high frequencies (f?>?1?kHz). The magnitude of this reduction was related to the volume of fluid. The displacement transmission ratio of the TM to incus varied with frequency and fluid level. The volume displacement ratio of the oval window to round window was approximately 1.0 over most frequencies. Elevation of ABR thresholds and prolongation of ABR latencies were observed as fluid level increased. Reduction of TM displacement correlated well with elevation of ABR threshold at 0.5-8?kHz. Alterations in the ratio of ossicular displacements before and after fluid induction are consistent with fluid-induced changes in complex ossicular motions.     

Standardisierte Messungen der Schallübertragung verschiedener Mittelohrprothesen

The sound transmission properties of three different commercially available middle ear implants and the prototype of a complete middle ear prosthesis (CoMEP) were evaluated with a special measurement system that permits standardized conditions. This system uses a mechanical middle ear model (MMM) which approximates the impedances of the tympanic membrane and inner ear. The implants were fitted under defined conditions into the MMM. Displacement of the artificial stapes footplate of the MMM was measured with an optical probe. The measurements of different middle ear prostheses showed that the mass of the implant was the most important factor for optimum high frequency transmission. The lightest implant (4 mg, titanium) showed the best results. The CoMEP revealed the highest sensitivity because of a slight enlargement of the diameter of the artificial tympanic membrane. These findings show that the CoMEP is able to restore sound transmission to a normal range. In a second experiment one of the implants was fitted into the MMM with different forces. The increase of stiffness produced a slightly better high frequency transmission at the expense of low frequency sensitivity. Hence, the fitting of the implant may not be too stiff because of its loss of mobility within a significant frequency range.     

Magnified tomography for identification of ceramic prostheses]

Recently, ceramic prostheses for ossicular replacement have become very popular in middle ear surgery. These prostheses have a good affinity with the surrounding tissue. But, it is difficult to identify the position of these prostheses postoperatively. We used magnified tomography in order to identify the implanted ceramic prostheses, and to determine whether these prostheses were in the appropriate position. In the case of patients without stapes, we usually use Apaceram type T, which restores ossicular continuity to the inner ear. When the shaft of the ceramic prosthesis is placed on the oval window niche, the overhanging Fallopian canal obstructs the tip of the prosthetic shaft to obtain the appropriate place in the oval window. The angle of the shaft should be slightly tilted inferiorly against the medial wall of the middle ear cavity.     

Ethanol infiltration into the stapedio-vestibular joint reduces low-frequency vibration of the ossicular chain and round window membrane in the guinea pig

Background: The synovial stapedio-vestibular joint (SVJ), which serves as a bridge between the stape and oval window, can be found in guinea pigs and most human adults. Unlike the fibrous SVJs in other animals, the contribution of the synovial SVJ to middle ear sound transmission remains unknown.

Aims/objectives: In this study, we investigate whether sclerosis of the synovial SVJ contributes to frequency-dependent vibration of the ossicular chain and round window membrane (RWM).

Materials and methods: A model of SVJ sclerosis model was established in the guinea pig using 75% ethanol. A laser Doppler vibrometer was then used to measure vibrations of the RWM and the long process of the incus (LPI) under pure tone sound stimulations of 0.25–16?kHz. The influence of SVJ sclerosis was analysed by comparing structural vibration displacement between the normal and sclerosis groups.

Results: Both LPI and RWM vibrations significantly decreased at low frequencies after infiltration of ethanol, which caused SVJ sclerosis.

Conclusions: SVJ sclerosis reduces low-frequency vibration of the ossicular chain and RWM in the guinea pig, which indicates that the synovial SVJ is vital to low-frequency sound transmission in the middle ear.

Significance: Providing useful data for further research regarding middle ear biomechanics.     

An anatomically shaped incus prosthesis for reconstruction of the ossicular chain

An anatomically shaped incus replica prosthesis has been designed to reconstruct the ossicular chain. A series of in vitro studies on human temporal bones evaluated the acoustic performance of this prosthesis and compared it with a Causse partial ossicular replacement prosthesis (PORP). Pure tones in the frequency range 0. 125-8 kHz stimulated the tympanic membrane at sound pressure levels of 80, 90 and 100 dB. Measurements of the stapes footplate velocity were made with a laser interferometer. The acoustic function of the ossicular chain reconstructed with the incus replica prosthesis was found to be within 10 dB of that of the original intact ossicular chain, when both the upper and lower joints of the implant were rigidly fixed in place. It was shown that a rigid mechanical contact between the ossicular prosthesis and ossicles is a prerequisite for effective sound transmission. The anatomically shaped incus prosthesis gave a 15-dB improvement on the PORP at frequencies below 1.5 kHz.