Evaluation of hydroxyapatite ossicular chain prostheses

The Utility of Numeric Grading Scales of Middle Ear Risk in Predicting Ossiculoplasty Hearing Outcomes

OBJECTIVE

To assess the usefulness of numeric grading scales of middle ear risk in predicting ossiculoplasty hearing outcomes.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary care, academic medical center.

PATIENTS

Adults and children undergoing ossiculoplasty between May 2013 and May 2019 including: synthetic ossicular replacement prosthesis, autograft interposition, bone cement repair, and mobilization of lateral chain fixation.

INTERVENTION

Cases were scored via middle ear risk index (MERI), surgical prosthetic infection tissue eustachian tube (SPITE) method, and ossiculoplasty outcome scoring parameter (OOPS) scale. Preoperative and postoperative hearing outcomes were recorded.

MAIN OUTCOME MEASURE

Statistical correlation between risk score and postoperative pure-tone average air-bone gap (PTA-ABG).

RESULTS

The 179 included cases had average pre and postoperative PTA-ABGs of 30.3dB (standard deviation [SD] 12.7) and 20.3dB (SD 11.1), respectively. Mean MERI, SPITE, and OOPS scores were 4.5 (SD 2.3), 2.8 (SD 1.7), and 3.1 (SD 1.8), respectively. Statistically significant correlations with hearing outcome were noted for all three methods (MERI r = 0.22, p = 0.003; OOPS r = 0.19, p = 0.012; SPITE r = 0.27, p < 0.001). No scale predicted poor (PTA-ABG > 30dB) outcomes; only low SPITE scores predicted excellent (PTA-ABG < 10dB) outcomes (odds ratio [OR] 0.74 [Confidence Interval: 0.57 - 0.97], p = 0.032).

CONCLUSIONS

Significant weak correlations between each middle ear risk score and hearing outcomes were encountered. Although only the SPITE method predicted postoperative PTA-ABG, it was not overwhelmingly superior. Current grading scale selection may be justified by familiarity or ease of use.

Long-term histological results of ossicular chain reconstruction using bioceramic implants

Middle ear problems are addressed using tympanoplasty, which requires a mobile tympanic membrane and secure sound-conducting mechanism. The present is a long-term, retrospective, non-controlled study on the results of ossiculoplasty using bioceramic implants of autochthonous origin and which defined the statistical relevant factors that could influence the rate of implant rejection. In a cohort of 108 patients ossiculoplasties with bioceramic implants were performed and patients were followed up clinically for a period of minimum 7 years. Several factors were identified that could influence the results of the implantation and the statistical correlations were studied. The rejection rate after 9.12 years was 21% (23 patients). Histological integration rate was 79% (85 patients), similar to results reported in literature for both bioceramic and titanium implants. Hydroxyapatite has many of the ideal characteristics required to be a good prosthesis with a high degree of biocompatibility, very low extrusion rate, low risk of disease transmission and good functional results. Although perhaps considered of historical interest, bioceramic implants are cheaper and can be produced locally, which is a great advantage for struggling economies.

Development of Cerium-Doped Hydroxyapatite Coatings with Antimicrobial Properties for Biomedical Applications

Antibacterial cerium-doped hydroxyapatite (Ce-HAp) layers have been researched sparingly in recent years. The Ce-HAp powder, Ca10−xCex(PO4)6(OH)2 with xCe = 0.05, was obtained by an adapted chemical co-precipitation method at room temperature. The target was prepared using the Ce-HAp (xCe = 0.05) powder sintered in air at 600 °C. The coatings on the Ti substrate were generated in plasma using a radio frequency (RF) magnetron sputtering discharge in an Ar gas flow in a single run. To collect the most complete information regarding the antimicrobial activity of cerium-doped hydroxyapatite with xCe = 0.05, (5Ce-HAp), antimicrobial studies were carried out both on the final suspensions and on the coated surfaces. The target was tested using ultrasound measurement, transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), glow-discharge optical emission spectroscopy (GDOES), and X-ray photoelectron spectroscopy (XPS). The present study exhibited for the first time results of the homogeneous coatings of hydroxyapatite doped with cerium using a radio frequency magnetron sputtering technique. In addition, this study highlighted for the first time the stability of the cerium-doped hydroxyapatite gels used in the creation of the coating. Ultrasound measurements on the concentrated suspension of 5Ce-HAp showed a good stability compared to double distilled, water which was chosen as the reference fluid. Particles with spherical shape were observed by both TEM and SEM analysis. The broadening of the IR bands in the IR spectrum of the 5Ce-HAp film in comparison with the IR spectrum of the precursor target indicate the formation of interlinked bonds into the layer bulk. XPS analysis revealed that the mixture of Ce3+ and Ce4+ ions in the hydroxyapatite (HAp) structure of the coatings could be due to the deposition process. The surface of 5Ce-HAp coatings was homogenous with particles having a spherical shape. A uniform distribution of all the constituent elements on the surface the 5Ce-HAp layer was revealed. The antimicrobial assays proved that both 5Ce-HAp suspensions and 5Ce-HAp coatings effectively inhibited the development of colony forming units (CFU) for all the tested microbial strains. Moreover, the antimicrobial assays emphasized that the 5Ce-HAp suspensions had a biocide effect against Escherichia coli (E. coli) and Candida albicans (C. albicans) microbial strains after 72 h of incubation.

Traumatic ossicular dislocations: etiology and management

OBJECTIVE

This study was conducted to discuss the etiologic factors, clinical-radiologic findings, and surgical outcomes in patients with traumatic ossicular pathology.

MATERIAL AND METHODS

Thirty-two patients with conductive hearing loss due to trauma were retrospectively analyzed. Their mean age was 24.56 +/- 7 years. The average delay from injury until treatment was 5.7 years. Air and bone conduction hearing thresholds were measured by pure tone audiometry on initial admission, at 1 month postoperatively and during follow-up at 6-month intervals. Mean follow-up time is 3.2 years. The hearing threshold was calculated as the mean value of the threshold for 500, 1000, 2000, and 3000 Hertz. All patients were evaluated by high-resolution computerized tomography of the temporal bone at axial and coronal sections before the surgery.

RESULTS

Traffic accident was the common cause of injury. Seven patients had temporal bone fracture. Six patients had facial paralysis ranging between House-Brackmann grades II and IV. Incudostapedial disarticulation was the most common ossicular pathology. Closure of air-bone gap within 10 and 20 decibels was observed in 37.6% and 71.9% of the patients, respectively. There is an improvement of 10 decibels or more in the hearing threshold of 27 (84.3%) patients.

CONCLUSIONS

Head trauma can be associated with ossicular disruption, which should be suspected in patients with conductive hearing loss that persists after a healing process of 2 months. The diagnosis can be best confirmed by tomography. Hearing results after immediate or delayed ossiculoplasty are apparently satisfying, although late cases are assumed to be associated with adhesion or fibrosis.

Is simultaneous bilateral mastoidectomy ever advisable?

Introduction:

We report our experience with bilateral, simultaneous tympanomastoidectomies and the results of an opinion survey of otologists.

Methods:

A chart review of 116 tympanomastoidectomies revealed 12 patients who underwent bilateral, simultaneous tympanomastoidectomies. An opinion survey generated 121 responses.

Results:

Of the 12 patients, none suffered any outcome which would have been avoided by staging the procedures. Twenty-three of 24 operated ears had the same or better hearing post-operatively. Of the survey respondents, 74 felt that performing bilateral, simultaneous tympanomastoidectomies was unsafe, largely because of the risk of bilateral sensorineural hearing loss.

Discussion:

Although bilateral, simultaneous tympanomastoidectomies carry double the risk of unilateral sensorineural hearing loss, compared with the unilateral procedure, the risk of bilateral sensorineural hearing loss is only 0.006–0.2 per cent, as derived mathematically from historical data. Respondents to the survey were mostly opposed to bilateral, simultaneous tympanomastoidectomies, but even those opposed gave indications for simultaneous procedures. This finding probably reflects an ambivalence about the theoretical risks of the operation versus the potential patient benefits. A decision tree for proceeding to the second case is presented.

Limitations of titanium dioxide and aluminum oxide as ossicular replacement materials: an evaluation of the effects of porosity on ceramic prostheses

BACKGROUND

Because the performance of titanium dioxide (TiO2) has not yet been assessed in the unique environment of the middle ear, its role as an ossicular replacement prototype in the form of a total ossicular replacement prosthesis (TORP) was tested and compared with aluminum oxide (Al2O3), once considered to be a suitable implant material.

METHODS

Ossiculoplasty was performed by implanting TORPs into the tympanic cavities of rabbits. After an implantation period of 28, 84, or 300 days, the petrous bones were extracted, whereby the biocompatibility of the prostheses was examined using light microscopy and scanning electron microscopy to determine morphologic changes in situ. Proper implant placement and functionality was tested via manual manipulation.

RESULTS

Mucosa was seen covering most of the implants by day 84. Inflammatory cells were not observed in any of the specimens examined. The macroporous TiO2 TORPs were subjected to osseous infiltration, material dissolution, and fragmentation, whereas the microporous TiO2 implants were subjected to an increasing frequency of fissure formations. The Al2O3 prostheses demonstrated signs of material dissolution by producing encapsulated aggregates during the experimental trial period.

CONCLUSIONS

Neither the macroporous nor microporous oxide ceramics were able to withstand the oscillatory stress to which they were continually subjected. Although porosity allows for the rapid integration of an implant material into a biological environment, its properties are not suited to fulfill the requirements of strength and long-term stability, which are demanded of middle ear prostheses.

Ossiculoplasty with total hydroxylapatite prostheses anatomical and functional outcomes

OBJECTIVE

To evaluate the results of partial and total ossicular reconstruction prostheses entirely made of hydroxylapatite.

STUDY DESIGN

A retrospective review of cases followed-up between 1997 and 2000.

SETTING

Tertiary referral center.

PATIENTS

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%).

INTERVENTION

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.

MAIN OUTCOME MEASURES

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.

RESULTS

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.

CONCLUSION

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.

Reporting results in ossiculoplasty

OBJECTIVE

To review and modify past methods of reporting ossiculoplasty results, improve analysis, standardize presentation formats, and achieve greater veracity of the reported outcomes.

STUDY DESIGN

A review of past and present evaluation methods.

BACKGROUND

Past ossiculoplasty evaluation methods have been often poorly comparable, based on questionable methodology, and frequently failed to adequately verify the results described. Guidelines set by the American Academy in 1995 to improve matters appear unsatisfactory in several respects.

METHODS

Past evaluation techniques and the Academy modifications are examined for areas that may be subject to modification and improvement, particularly the choice of audiologic frequencies, the calculation of the air-bone gap, and the description of the pathologic findings within the caseload itself.

FINDINGS

Some audiologic measures and disease evaluations are potentially inaccurate or inadequate. The Academy frequency selections may be flawed. Insufficient emphasis is given to the evaluation of case pathologic findings, which is the major factor pertinent in series comparisons and preoperative case prognostication.

CONCLUSIONS

Further in-depth analysis of reporting methods is overdue. The matter is one of an international measure standard and should be subject to a global discussion, written and oral, to produce an adequately researched and formulated consensus. This in turn may provide the clinical and theoretical tools by which this troubled area can be more effectively analyzed.

Development of interface in hydroxyapatite implanted in the middle ear of the rat: a light and scanning microscopy study

OBJECTIVE

The aim of this work is to study the chronology in the biological covering of the hydroxyapatite bioprostheses in the healthy middle ear of the rat.

STUDY DESIGN AND SETTING

Dense hydroxyapatite is implanted into the middle ear of 45 Long-Evans rats, between stapes and tympanic membrane. The sample was divided into 3 groups for morphologic, functional, and chemical studies at 15 days, 3 months, and 6 months after surgery, respectively.

RESULTS

The short-term studies reveal that the prostheses is surrounded by a fibrous epithelial tissue referred as the interface; it presents a marked inflammatory reaction that decreases gradually in the medium-term and long-term studies; in this way, we observe a progressive adhesion between implant and the contact tissues.

CONCLUSIONS AND SIGNIFICANCE

This model has enabled us to study the cell reaction produced by the contact of the prostheses with bone and soft tissue and their impact on the functional qualities of the prostheses.

Over-under tympanoplasty

OBJECTIVE

Common techniques of tympanic membrane repair include underlay and overlay grafting. The over-under tympanoplasty, an innovative method for tympanic membrane repair, will be described as a reliable alternative that has advantages over traditional procedures.

STUDY DESIGN

This study was a retrospective case review.

SETTING

Tertiary referral center with hospital-setting surgery and outpatient ambulatory patient visits.

PATIENTS

One hundred twenty patients who underwent over-under tympanoplasty were included in this study. Average follow-up was 1.8 years.

INTERVENTION

Over-under tympanoplasty is performed by placing the graft over the malleus and under the annulus. This technique was used for patients undergoing ear surgery for chronic otitis media, perforations, cholesteatoma, and/or conductive hearing loss. All degrees of ear pathology were included.

MAIN OUTCOME MEASURES

Main outcome measures were graft success (no perforation, atelectasis, or lateralization within 6 mo) and improvement of hearing. Patients were stratified by severity of disease (according to the Middle Ear Risk Index), cholesteatoma presence, and type of mastoidectomy.

RESULTS

All 120 patients had successful grafts. Lateralization of the grafted drum did not occur. Seventeen patients had late atelectasis, and 12 patients had late perforations; nearly all of these were noted more than 1 year after surgery and were attributed to persistent eustachian tube dysfunction or infections. Average improvement in air-bone gap for all patients was 5.3 dB, whereas speech reception threshold improved by 5.9 dB.

CONCLUSION

Over-under tympanoplasty has an excellent success rate while being technically easier than lateral tympanoplasty. Thus, it is a useful method for practitioners of all levels.