Prophylactic antibiotics has no benefit for outcome in clean myringoplasty-A register-based cohort study from SwedEar

OBJECTIVES

To investigate if prophylactic antibiotics (PA) in conjunction with myringoplasty of clean and uninfected ears entails a reduction of postoperative infections within 6 weeks after surgery, and whether it affects the healing rate of the tympanic membrane (TM) at follow-up, 6-24 months after surgery.

DESIGN

A retrospective cohort study of prospectively collected data.

SETTING

Data extracted from The Swedish Quality Register for Ear Surgery (SwedEar), the years 2013-2019.

PARTICIPANTS

All patients in SwedEar with a registered clean conventional myringoplasty (tympanoplasty type I) including a follow-up visit.

MAIN OUTCOME MEASURES

The effect of PA use on TM healing rate at follow-up and postoperative infection within 6 weeks of surgery.

RESULTS

In the study group (n = 1665) 86.2% had a healed TM at follow-up. There was no significant difference between the groups that had PA administered (87.2%) or not (86.1%). A total of 8.0% had a postoperative infection within 6 weeks. Postoperative infection occurred in 10.2% of the group that received PA (n = 187) compared with 7.7% of the group that did not receive PA. However, this difference was not statistically significant. Postoperative infection within 6 weeks significantly lowered the frequency of healed TMs.

CONCLUSION

PA administered during clean conventional myringoplasty does not improve the chance of having a healed TM at follow up, nor decrease the risk of having a postoperative infection within 6 weeks after surgery.

Evaluating Treatments for Ménière's Disease: Controversies Surrounding Placebo Control

Although double-blind experimental designs are considered the gold standard for documenting treatment effectiveness, many treatments for Ménière's disease have not been evaluated using this methodology. Particularly with a disease characterized by exacerbation and remission, carefully controlled, long-term studies are required. The nature of the placebo effect is described in this article, and the concept of debonafide effect introduced. Ideally, patients should be given treatments supported by evidence-based medicine that have the lowest possible risk of side effects. However, risk minimization may dictate using treatments that have not been proven effective and may evoke debonafide effects.

The effect of rosmarinic acid on the prevention of myringosclerosis

OBJECTIVES

Myringosclerosis commonly occurs as a long-term complication of ventilation during the treatment of otitis media. We aimed to determine the effects of rosmarinic acid as an antioxidant on experimentally induced myringosclerosis.

METHODS

Twenty-four male Sprague-Dawley rats, weighing 250-300 g, were unilaterally myringotomized and randomly separated into three groups. Group 1 received no treatment (control group) (n = 8); Group 2 received topical rosmarinic acid (n = 8); Group 3 received oral rosmarinic acid (n = 8). On the twenty-first day, the right ears were examined by otomicroscope and findings of myringosclerosis were recorded. Finally, all of the rats were euthanized and the tympanic membrane (TM) thickness and the severity of middle ear mucosal inflammation were evaluated histopathologically.

RESULTS

The myringosclerosis severity, TM thickness, and inflammation scores were found to be significantly higher in the control group than in the topical and systemic treatment groups (p < 0.05). There were no statistically significant differences in terms of TM thickness and inflammation scores between the topical and systemic treatment groups (p > 0.05). While moderate and severe myringosclerosis were higher in the control group, mild myringosclerosis was found to be higher in both treatment groups.

CONCLUSION

The local and oral administration of rosmarinic acid suppressed inflammation, reduced TM thickness, and prevented the development of myringosclerosis in myringotomized rats.

Effects of an enrofloxacin-silver sulfadiazine emulsion in the ears of rabbits with perforated tympanic membranes

OBJECTIVE

To determine whether an enrofloxacin-silver sulfadiazine emulsion (ESS) labeled for treatment of otitis externa in dogs has ototoxic effects in rabbits following myringotomy.

ANIMALS

6 healthy adult New Zealand White rabbits.

PROCEDURES

Rabbits were anesthetized for brainstem auditory-evoked response (BAER) tests on day 0. Myringotomy was performed, and BAER testing was repeated. Saline (0.9% NaCl) solution and ESS were then instilled in the left and right middle ears, respectively, and BAER testing was repeated prior to recovery of rabbits from anesthesia. Application of assigned treatments was continued every 12 hours for 7 days, and rabbits were anesthetized for BAER testing on day 8. Rabbits were euthanized, and samples were collected for histologic (6 ears/treatment) and scanning electron microscopic (1 ear/treatment) examination.

RESULTS

Most hearing thresholds (11/12 ears) were subjectively increased after myringotomy, with BAER measurements ranging from 30 to 85 dB in both ears. All day 8 hearing thresholds exceeded baseline (premyringotomy) values; results ranged from 30 to 85 dB and 80 to > 95 dB (the upper test limit) in saline solution-treated and ESS-treated ears, respectively. All ESS-treated ears had heterophilic otitis externa, epithelial hyperplasia of the external ear canal, various degrees of mucoperiosteal edema, and periosteal new bone formation on histologic examination. Scanning electron microscopy revealed that most outer hair cells in the ESS-treated ear lacked stereocilia or were absent.

CONCLUSIONS AND CLINICAL RELEVANCE

Results supported that ESS has ototoxic effects in the middle ear of rabbits. Further research is needed to confirm these findings. Myringotomized laboratory rabbits may be useful to study ototoxicity of drugs used in human medicine.

A comparative study to evaluate the efficacy of EGF, FGF-2, and 0.3% (w/v) ofloxacin drops on eardrum regeneration

BACKGROUND

Traumatic tympanic membrane perforations (TMPs) tend to spontaneous healing, however, large TMPs usually fail to healing. Clinical and experimental studies had demonstrated that growth factors accelerated the healing of large TMPs. The aim of this study was to compare the effects of growth factors and 0.3% (w/v) ofloxacin drops n the healing of human large TMPs.

METHODS

A total of 184 human large traumatic TMPs were randomly assigned to receive epidermal growth factor (EGF) treatment, fibroblast growth factor-2 (FGF-2) treatment, 0.3% (w/v) ofloxacin drops treatment, and conservative observation (only).

RESULTS

A total of 180 patients were analyzed in this study at the 6-month follow-up. The closure rates of the perforations in the EGF, FGF-2, 0.3% (w/v) ofloxacin drops, and conservative observation groups were 91.11%, 93.18%, 95.65%, and 82.22%, respectively, the closure rates did not significantly differ among the groups (P = .165). Similarly, pairwise comparisons did not reveal any significant between-group differences (P > .0083). However, the difference of the mean closure time was significant among the 4 groups (P < .001), pairwise comparisons showed that closure time was significantly longer in the observational group than in the other 3 groups (P < .001). Nevertheless, no significant difference in mean closure time was evident between any 2 treated groups (P > .0083). The mean hearing gain after 6 months was 11.49 ± 5.88 dB for the EGF group, 10.89 ± 5.16 dB for the FGF-2 group, 10.54 ± 5.56 dB for the ofloxacin group, and 9.29 ± 5.36 dB for the observation group. Differences in hearing improvement rates among the 4 groups were not statistically significant (P = .283).

CONCLUSION

Epidermal growth factor, FGF-2, and 0.3% (w/v) ofloxacin drops accelerated the closure of large TMPs compared with conservative treatment. Surprisingly, neither the closure rate nor closure time differed significantly among the 3 treated groups. Further experimental studies to demonstrate whether 0.3% (w/v) ofloxacin per se accelerates the healing of TMPs will be interesting in the future.

Efficacy of oral vs. intratympanic corticosteroids in sudden sensorineural hearing loss

BACKGROUND

The current standard treatment for sudden sensorineural hearing loss (SSNHL) comprises of tapered course of oral corticosteroids. Intratympanic steroids are introduced as another modality of treatment, but management of SSNHL continues to be debatable. The present study was designed to evaluate the efficacy of steroids given orally and by the intratympanic route.

METHODS

A prospective, randomized, open-labeled study was conducted involving 42 patients. These were randomly divided into two groups; group I patients received oral prednisone tapered over 14 days, and group II patients were treated with intratympanic methylprednisolone (40 mg/mL). One milliliter of the drug solution containing 40 mg of the drug (40 mg/mL) was injected into the middle ear cavity through the trans-tympanic route. The drug was injected twice a week for 2 weeks. The total duration of the study was 60 days, and hearing outcome was assessed on the basis of change in pure tone average.

RESULTS

An improvement of 18.24±8.72 dB was recorded in group I patients treated with oral prednisone in comparison to 14.68±12.88 dB improvement in group II. Statistically significant improvement in hearing was observed in both groups, but it was not significant when group I and group II were compared.

CONCLUSIONS

The post-treatment outcomes among patients who receive either oral prednisone or intratympanic methylprednisolone within 2 weeks of onset of symptoms were comparable. The outcomes were affected by degree of hearing loss and association of SSNHL with vertigo.

The effect of caffeic acid phenethyl ester (CAPE) on tympanosclerosis

OBJECTIVE

To investigate the effects of caffeic acid phenethyl ester (CAPE) on tympanosclerosis.

MATERIALS AND METHODS

Thirty-two male Sprague Dawley rats were separated into 4 groups as CAPE (n = 10), alcohol (n = 10), control (n = 8) and normal (n = 4) groups. All tympanic membranes except normal group were myringotomised and type 3 Streptococcus pneumoniae strains was injected into their middle ears. Myringotomies were repeated for 5 weeks. Intraperitoneal (i.p) CAPE were administrated to the CAPE group at 10 μmol/kg/day and 10% ethyl alcohol administrated to the alcohol group for 5 weeks. The control group were left untreated. Findings of myringosclerosis were recorded by otomicroscope at sixth week. Then, all rats were sacrificed and tympanic membrane thickness and severity of middle ear mucosal inflammation evaluated histopathalogically.

RESULTS

Severity of myringosclerosis was significantly higher in the alcohol and control groups compared to the CAPE group (p < 0.001), but was not significant when alcohol and control groups were compared (p = 0.17). The tympanic membrane thickness measured in the alcohol and control groups were significantly higher compared to the CAPE group (p < 0.001), but was not significant when alcohol and control groups were compared (p = 0.17). The severity of inflammation in the middle ear mucosa was significantly higher in the alcohol and control groups compared to the CAPE group (respectively, p < 0.001, p = 0.03). The severity of inflammation in the middle ear mucosa was not significant between alcohol and control groups (p = 0.30).

CONCLUSION

CAPE has anti-inflammatory and antioxidant effects on the development of MS in myringotomized rats, so reduces the severity of tympanosclerosis.

Dose-dependent cochlear and vestibular toxicity of trans-tympanic cisplatin in the rat

In vivo studies are needed to study cisplatin ototoxicity and to evaluate candidate protective treatments. Rats and mice are the preferred species for toxicological and pharmacological pre-clinical research, but systemic administration of cisplatin causes high morbidity in these species. We hypothesized that trans-tympanic administration of cisplatin would provide a good model for studying its auditory and vestibular toxicity in the rat. Cisplatin was administered by the trans-tympanic route in one ear (50μl, 0.5-2mg/ml) of rats of both sexes and two different strains. Cochlear toxicity was corroborated by histological means. Vestibular toxicity was demonstrated by behavioral and histological analysis. Cisplatin concentrations were assessed in inner ear after trans-tympanic and i.v. administration. In all experiments, no lethality and only scant body weight loss were recorded. Cisplatin caused dose-dependent cochlear toxicity, as demonstrated by hair cell counts in the apical and middle turns of the cochlea, and vestibular toxicity, as demonstrated by behavioral analysis and hair cell counts in utricles. High concentrations of cisplatin were found in the inner ear after trans-tympanic administration. In comparison, i.v. administration resulted in lower inner ear concentrations. We conclude that trans-tympanic administration provides an easy, reproducible and safe model to study the cochlear and vestibular toxicity of cisplatin in the rat. This route of exposure may be useful to address particular questions on cisplatin induced ototoxicity and to test candidate protective treatments.

Transtympanic Gentamicin and Fibrin Tissue Adhesive for Treatment of Unilateral Menière's Disease: Effects on Vestibular Function

OBJECTIVE: To determine the effects of transtympanic injections, with a mixture composed of gentamicin and fibrin tissue adhesive (FTA), on vestibular function of patients with intractable unilateral Menière's disease.

STUDY DESIGN: This was an open, prospective study.

SETTING AND PATIENTS: The study was performed at 2 tertiary referral centers. Twenty-six patients affected by “definite” unilateral Menière's disease, unresponsive to medical therapy for at least 6 months, were enrolled.

INTERVENTION: A buffered gentamicin solution mixed with FTA was injected in the middle ear until the development of bedside vestibular hypofunction signs and/or caloric weakness in the treated ear.

MAIN OUTCOME MEASURE: Vestibular function was evaluated by 3 bedside vestibular tests (observation of spontaneous nystagmus, head shaking test, and head thrust test) and by a caloric test. Tests were performed on days 10 and 30 after completion of treatment. Tests were also performed 3, 6, and 12 months from completion of the gentamicin-FTA protocol. The effects of treatment were also assessed in terms of hearing levels, control of vertigo, and disability status.

RESULTS: In 22 of the 26 patients, only 1 gentamicin-FTA injection was necessary to obtain 1 or more signs indicating a reduction of the vestibular function in the treated ear. Four patients needed another treatment because of the persistence of their incapacitating symptoms during the follow-up. Four patients needed more than 1 injection to obtain a vestibular hypofunction. None of the patients who received 1 or 2 injections presented hearing loss in direct temporal relationship to the treatment.

CONCLUSIONS: A mixture of gentamicin and fibrin glue makes it possible to considerably reduce the number of administrations in patients with intractable unilateral Menière's disease. Spontaneous nystagmus, post head shaking nystagmus, and a head thrust sign are the clinical signs that indicate onset or progression of unilateral vestibular hypofunction. These signs were obtained with only 1 injection in 81% of patients.

EBM RATING: C

Intratympanic Steroid Injection for Treatment of Idiopathic Sudden Hearing Loss

Objective.

To conduct a clinical trial of intratympanic steroid injection for idiopathic sudden sensorineural hearing loss in subjects who failed oral steroid therapy.

Study Design and Setting.

Open-label methylprednisolone injection clinical trial in a tertiary neurotologic referral center. Twenty subjects (14 males; 6 females) received 4 injections within a 2-week period (4 days apart). Hearing, dizziness/p, and tinnitus were evaluated before and after treatment.

Results.

There were no serious unexpected adverse events and 2 types of expected adverse events (tympanic membrane perforation, nausea after injection). No increases in dizziness or tinnitus lasting longer than 24 hours were observed after injections. One of 20 (5%) improved to near-normal hearing. In addition, there was statistically significant improvement in 4-frequency pure-tone average and speech discrimination score at 1 month after treatment.

Conclusion.

Four intratympanic injections of methylprednisolone improved pure-tone average or speech discrimination scores for a subset of sudden hearing loss subjects that failed to benefit from oral steroids.

Significance.

A clinical trial of intratympanic injections for idiopathic sudden hearing loss was successfully completed and promising results were found.

Hearing outcome does not depend on the interval of intratympanic steroid administration in idiopathic sudden sensorineural hearing loss

We studied the effect of intratympanic steroid administration with different intervals on hearing outcomes in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). The subjects were 197 consecutive patients (197 ears) with ISSNHL (hearing level ≥40 dB, interval between onset and treatment ≤30 days). They received systemic administration of prednisolone (100 mg followed by tapered doses) combined with intratympanic injection of dexamethasone (4 mg/ml). Intratympanic injection was performed once a week for 4 weeks in 105 patients (long-interval group), or 4 times in 1 week in 92 patients (short-interval group). The hearing outcomes were evaluated at two points of time: 1 week from the start of treatment, and 1-2 months after the completion of treatment when the hearing level reached a plateau. There was no significant difference in the cure rate, marked-recovery rate, recovery rate, hearing gain, hearing level, or percent hearing improvement between the long- and short-interval groups at either point of time. Multiple regression analysis also showed that the final hearing level did not depend on the interval of intratympanic steroid injection. These results indicate that the hearing outcome of ISSNHL does not improve even if the interval of intratympanic injection is shortened. This implies that a lower total number of intratympanic steroid injections may be as effective as the present protocol.

Extending Myringotomy Patency with Topical Everolimus in Rats

BACKGROUND

Everolimus is an immunosuppressant agent that has antiproliferative properties and negative effects on wound healing. The effect of everolimus use to delay the closure time of myringotomy is not known.

OBJECTIVES

The aim of the study was to evaluate the impact of topical everolimus on myringotomy patency and to investigate its histopathologic effects on the tympanic membrane.

MATERIAL AND METHODS

Twenty Sprague-Dawley rats were bilaterally myringotomized with a myringotomy knife. Gelfoam soaked in 0.05% everolimus in a microemulsion formulation was applied to the right myringotomy site of the rats for 10 min (the everolimus group). The myringotomy sites of the left ears were treated with sterile saline topically (the control group). The tympanic membranes were routinely examined otomicroscopically every other day for 31 days. The membranes were then harvested and evaluated histologically after 31 days.

RESULTS

All tympanic membranes were closed by the 15(th) day in the control group, while in the everolimus group the myringotomy remained open in five rats (25%) on day 31. The mean durations of myringotomy patency in the everolimus group and control group were 20.90 ± 7.85 and 10.10 ± 3.14 days, respectively. The difference was found to be statistically significant (p < 0.01). In the histopathological examination of the tympanic membranes, there was less fibrosis and less inflammation in the everolimus group than in the control group (p < 0.01).

CONCLUSIONS

Topical everolimus application is effective in extending myringotomy patency in rat tympanic membranes. Inflammatory reactions and fibrosis in the lamina propria were observed to be significantly less when topical everolimus was used.

Effect of absorbable gelatin sponge in the middle ear: in vitro and in vivo animal model

CONCLUSION

GelitaSpon gelatin sponge (GS) showed faster reabsorption than gelfoam (GF) in vitro, and GS-packed middle ears resulted in a faster hearing recovery and less inflammation than the ears packed with GF soaked in saline. Soaking GF sponges with boric acid (BA) appeared to offset the inflammatory response of saline-soaked GF, making this inflammatory response comparable to that of GS-packed ears.

OBJECTIVE

To describe the reabsorption and inflammatory effects of absorbable gelatin sponge in the middle ear.

METHODS

For in vitro evaluation, GF and GS were used as disks immersed in saline solution or 3% BA and placed in gel. Images were captured with a microscope and processed using image processing Toolbox. For in vivo tests, 16 female albino Sprague Dawley rats were divided into four groups: bulla opening; GF + 0.9% saline; GF + BA; and GS + 0.9% saline. An anterior approach to the right bulla was used for surgery. Preoperative and postoperative auditory brainstem response thresholds were measured.

RESULTS

In vitro, there was marked degradation of GF by day 14, while GS showed complete degradation by the third day. In vivo, hearing recovery occurred by day 21. GF produced a more severe inflammatory response, which could be reduced by treating the GF with BA.

Evaluation of the selective glucocorticoid receptor agonist compound A for ototoxic effects

OBJECTIVES/HYPOTHESIS

To evaluate the selective glucocorticoid receptor agonist (SEGRA) compound A, a potential novel therapeutic for inner ear disorders, for ototoxic effects.

STUDY DESIGN

Laboratory animal study.

METHODS

Experimental guinea pigs were grouped as follows: Systemic application of compound A (1.5 mg/kg and 4.5 mg/kg; n = 6/group) and intratympanic application of compound A (1 mM and 10 mM; n = 6/group). Contralateral ears in topically treated animals served as controls. Hearing thresholds were determined by auditory brainstem response before and directly after the application of compound A, as well as on days 3, 7, 14, 21, and 28. At the end of the experiments, temporal bones were harvested for histological evaluation.

RESULTS

Systemic administration of compound A (1.5 mg/kg and 4.5 mg/kg) did not cause hearing threshold shifts, whereas the intratympanic injection (1 mM and 10 mM) resulted in a hearing loss. Histological analysis of the middle and inner ears after topical compound A application showed alterations in the tympanic membranes, the auditory ossicles, and the round window membranes, whereas spiral ganglion cells and hair cells were not affected.

CONCLUSION

SEGRAs such as compound A could provide novel therapeutic options for the treatment of inner ear disorders and reduce metabolic side effects. Whereas the intratympanic application of compound A resulted in a hearing loss, the systemic application of compound A merits evaluation for otoprotective effects in trauma models.

Effects of basic fibroblast growth factor dose on traumatic tympanic membrane perforation

OBJECTIVE

To compare the healing outcomes of higher and lower doses of basic fibroblast growth factor (bFGF) on human traumatic tympanic membrane perforation (TMP).

STUDY DESIGN

Prospective clinical study.

METHODS

All patients with traumatic TMP were treated by direct application of bFGF, and were sequentially allocated into one of two groups: lower-dose group (2-3 drops of bFGF solution daily, approximately 0.1-0.15 mL) and higher-dose group (5-6 drops of bFGF solution daily, approximately 0.25-0.3 mL). The results of closure rate, closure time, and rate of otorrhea between the higher- and lower-dose groups were compared at 3 months.

RESULTS

In total, 126 patients were included in this study. The higher-dose group showed significantly improved purulent otorrhea rate compared with the lower-dose group (p < 0.01) for perforations of the same size, although the closure rate of the middle-sized perforations did not differ significantly between higher- and lower-dose groups (p > 0.05). However, the lower-dose group had a significantly shorter closure time of 5 d compared with the higher-dose group (p < 0.05). In addition, although the lower-dose group showed shorter healing times (about 3 d) compared to the higher-dose group for large-sized perforations, the dosage of bFGF did not significantly affect the large-sized perforation closure rate (p > 0.05) or closure time (p > 0.05). Nine large-sized perforations with secondary purulent otorrhea achieved complete closure, with closure times of 7-25 (14.2 ± 5.8) d.

CONCLUSION

This study suggested that continued daily application of a lower dose of bFGF not only shortens the closure time of human traumatic TMP but also avoids secondary purulent otorrhea.

Bacterial cellulose nanofibrillar patch as a wound healing platform of tympanic membrane perforation

Bacterial cellulose (BC)-based biomaterials on medical device platforms have gained significant interest for tissue-engineered scaffolds or engraftment materials in regenerative medicine. In particular, BC has an ultrafine and highly pure nanofibril network structure and can be used as an efficient wound-healing platform since cell migration into a wound site is strongly meditated by the structural properties of the extracellular matrix. Here, the fabrication of a nanofibrillar patch by using BC and its application as a new wound-healing platform for traumatic tympanic membrane (TM) perforation is reported. TM perforation is a very common clinical problem worldwide and presents as conductive hearing loss and chronic perforations. The BC nanofibrillar patch can be synthesized from Gluconacetobacter xylinus; it is found that the patch contained a network of nanofibrils and is transparent. The thickness of the BC nanofibrillar patch is found to be approximately 10.33 ± 0.58 μm, and the tensile strength and Young's modulus of the BC nanofibrillar patch are 11.85 ± 2.43 and 11.90 ± 0.48 MPa, respectively, satisfying the requirements of an ideal wound-healing platform for TM regeneration. In vitro studies involving TM cells show that TM cell proliferation and migration are stimulated under the guidance of the BC nanofibrillar patch. In vivo animal studies demonstrate that the BC nanofibrillar patch promotes the rate of TM healing as well as aids in the recovery of TM function. These data demonstrate that the BC nanofibrillar patch is a useful wound-healing platform for TM perforation.

Age-related cochlear cytokine gene expression in the BALB/cJ mouse with systemic versus intratympanic dosing of steroid drugs

CONCLUSION

Age-related differences in the expression of inflammatory cytokines in the inner ear may contribute to the development of age-related hearing loss (ARHL).

OBJECTIVES

ARHL is characterized by tissue remodeling, ischemia, ion homeostasis, and inflammation. Steroid therapy is an otoprotective strategy that likely acts by reducing inflammation. We examined age-related changes in cytokine gene expression in the cochlea of the BALB/cJ mouse model of premature ARHL after systemic or intratympanic steroid delivery.

METHODS

'Young' (2.5-3 months) and 'Old' (5-9 months) mice were treated with dexamethasone or fludrocortisone administered either orally or intratympanically. Cytokine gene expression in cochlear RNA was analyzed using prefabricated cDNA arrays. Old groups were compared to Young groups to identify age-related changes.

RESULTS

Down-regulation of a cytokine associated with bone remodeling (SPP1) was observed in the untreated Old group. Numerous genes were up- or down-regulated by more than twofold by steroid treatment, including proinflammatory interleukins (IL-16) and anti-inflammatory cytokines.

Healing of laser-induced tympanic membrane perforations in rats: no contribution of granulocyte colony-stimulating factor or Gelfoam

OBJECTIVES

To study whether granulocyte colony-stimulating factor together with Gelfoam (absorbable gelatin sponge, USP) could enhance the healing of freshly perforated tympanic membranes. The frequency and occurrence of different immunocompetent cells and collagen types was noted.

METHODS

Laser perforations were made in the tympanic membrane of rats that were sacrificed at different time intervals post-myringotomy: Day 1, 3, 6, and 12. Tympanic membrane specimens were embedded and sections were stained with hematoxylin/eosin and an immunohistochemical technique was used, with antibodies against macrophages, B-cells, T-cells, and type I-IV collagens. Semi-quantification was performed after counting positive cells, mean values were calculated and analyzed statistically.

RESULTS

All perforations, except one, had closed by Day 12 and no difference was observed between experimental and control ears at the other time points. Gelfoam was still present in a high amount at Day 12. The sections were initially stained positive for type I and II collagen, but after Day 6, the regenerating tissue stained positive for mainly type III and IV collagens. Results showed that the recruitment of macrophages, B-cells, and T-cells could not be mapped with a statistical significance.

CONCLUSIONS

This study showed that at 6-12 days post-laser myringotomy, type III and IV collagen has replaced the collagen type II that normally constitutes the healthy tympanic membrane. There is a concern for excessive scarring involving adjacent structures. It was also seen that the combination of Gelfoam and granulocyte colony-stimulating factor or saline did not affect the healing times in perforated tympanic membranes. No significant results regarding the inflammatory cell recruitment could be obtained on the studied time points or between experimental and control ears, except for in the Gelfoam matrix.

Ototoxic effect of topical oxiconazole and terbinafine in rats

OBJECTIVE

To assess the ototoxic effects of topically applied oxiconazole and terbinafine by means of auditory brainstem responses in rats.

DESIGN

Nonrandomized, controlled trial.

SETTING

Tertiary referral centre.

MATERIAL AND METHODS

The experiment was performed in 36 mature male Wistar albino rats. The study was conducted on four groups of rats: 10 rats received 1% oxiconazole cream, 10 rats received 1% terbinafine cream, 8 rats had gentamicin solution (40 mg/mL), and 8 rats had saline solution. A total perforation was created on the left tympanic membrane. The agents used in the study were administered to the left middle ears of the animals twice daily through a transcanal route, in doses of 0.1 cc, for 10 days.

MAIN OUTCOME MEASURES

Auditory brainstem response thresholds were obtained before the treatment and 7 days after termination of the application.

RESULTS

The differences in pre- and posttreatment thresholds for all stimuli (click, 1000 Hz, 4000 Hz) in auditory brainstem responses were statistically significant in the oxiconazole, terbinafine, and gentamicin groups (p < .0125). When the saline and gentamicin groups were compared to the other groups, auditory brainstem response threshold findings for all stimuli after the treatment showed statistically significant differences (p < .05).

CONCLUSION

Oxiconazole and terbinafine showed ototoxic effects reflected by elevated auditory brainstem response thresholds at the speech frequencies after being topically applied to the middle ear of rats. Further studies are needed to determine whether these auditory brainstem response threshold shifts are permanent.

Oral vs intratympanic corticosteroid therapy for idiopathic sudden sensorineural hearing loss: a randomized trial

CONTEXT

Idiopathic sudden sensorineural hearing loss has been treated with oral corticosteroids for more than 30 years. Recently, many patients' symptoms have been managed with intratympanic steroid therapy. No satisfactory comparative effectiveness study to support this practice exists.

OBJECTIVE

To compare the effectiveness of oral vs intratympanic steroid to treat sudden sensorineural hearing loss.

DESIGN, SETTING, AND PATIENTS

Prospective, randomized, noninferiority trial involving 250 patients with unilateral sensorineural hearing loss presenting within 14 days of onset of 50 dB or higher of pure tone average (PTA) hearing threshold. The study was conducted from December 2004 through October 2009 at 16 academic community-based otology practices. Participants were followed up for 6 months.

INTERVENTION

One hundred twenty-one patients received either 60 mg/d of oral prednisone for 14 days with a 5-day taper and 129 patients received 4 doses over 14 days of 40 mg/mL of methylprednisolone injected into the middle ear.

MAIN OUTCOME MEASURES

Primary end point was change in hearing at 2 months after treatment. Noninferiority was defined as less than a 10-dB difference in hearing outcome between treatments.

RESULTS

In the oral prednisone group, PTA improved by 30.7 dB compared with a 28.7-dB improvement in the intratympanic treatment group. Mean pure tone average at 2 months was 56.0 for the oral steroid treatment group and 57.6 dB for the intratympanic treatment group. Recovery of hearing on oral treatment at 2 months by intention-to-treat analysis was 2.0 dB greater than intratympanic treatment (95.21% upper confidence interval, 6.6 dB). Per-protocol analysis confirmed the intention-to-treat result. Thus, the hypothesis of inferiority of intratympanic methylprednisolone to oral prednisone for primary treatment of sudden sensorineural hearing loss was rejected.

CONCLUSION

Among patients with idiopathic sudden sensorineural hearing loss, hearing level 2 months after treatment showed that intratympanic treatment was not inferior to oral prednisone treatment.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00097448.

Hyperglycemia after intratympanic dexamethasone treatment in a diabetic patient

The treatment of patients with idiopathic sudden sensorineural hearing loss must be performed as an emergency measure in order to prevent long term hearing deficit. Steroids in monotherapy provide the best outcome. There is some controversy regarding the most efficient route but in order to prevent side effects, intratympanic treatment is the preferred choice, especially in diabetic patients. We here present the case of a patient that developed hyperglycemia after systemic and intratympanic dexamethasone treatment for sudden hearing loss. We conclude that after intratympanic treatment great caution must be taken.

The effect of melatonin on experimentally-induced myringosclerosis in rats

OBJECTIVES

This study determined the preventive effect of melatonin on the occurrence of experimentally-induced myringosclerosis of the tympanic membrane (TM).

MATERIALS AND METHODS

Twenty Wistar albino-type rats weighing approximately 300 g each were randomly separated into two groups and myringotomized on the left TMs: group 1 rats (n=6) received intraperitoneal melatonin injections 10 mg/kg/day whereas group 2 rats (n=12) were treated with physiological serum only. The remaining two rats were served as the control group for histological comparison and standardization. After 15 days of treatment, myringotomized membranes were examined by otomicroscopy and harvested for histopathological evaluation. The functional effect of myringosclerotic plaques in the TMs of the two groups were compared with tympanometric measurements.

RESULTS

Tympanic membranes in group 2 revealed extensive myringosclerotic plaques, on the other hand, TMs in group 1 showed faint or no existence of myringosclerosis. The mean magnitude of the maximum admittance from group 2 measured by tympanometry reduced to about 40% of the values obtained from group 1 (Z=-2,067, p=0.041). The mean magnitude of the maximum admittance from melatonin group was very close to the mean tympanometric value of non-myringotomized Wistar albino rats, demonstrating a functional outcome.

CONCLUSION

The occurrence of myringosclerosis following experimental myringotomy can be hindered by systemic melatonin treatment.

The influence of inhibition of the epidermal growth factor receptor on tympanic membrane wound healing in rats

Recently, a report on a bilateral tympanic membrane (TM) perforation in a patient after long-term treatment with erlotinib was published. The object of this study was to investigate the destructive potential of topical applied epidermal growth factor receptor (EGFR) inhibitors on wound healing of experimental TM perforation in rats by evaluating closure rates and histology. In 12 rats, erlotinib (10&#x00A0;mg/ml) was applied to one TM of each animal and cetuximab (5&#x00A0;mg/ml) to the other side daily for 12 consecutive days. Both the erlotinib group (11.8 days) and cetuximab group (9 days) had prolonged healing latencies compared to a reference value (7 days). We observed differences in the histologic parameters between both groups. Our results suggest that in normal TM, the inhibition of EGFR does not lead to a persistent perforation. However, in case of preexisting TM pathology, a spontaneous perforation in patients under long-term treatment of EGFR inhibitors seems to be possible.

Efficacy of topical halofuginone in myringotomy patency

The objective of the study is to determine whether topical halofuginone (HF) application has an impact on prolonging the time for healing of myringotomy incision, and to investigate histopathologic effects of HF on tympanic membrane (TM) in rat model. Forty rats with normal eardrums were involved in this study. The study group and control group consisted of 30 and 10 rats, respectively. A posterior incision 1 mm in diameter was made on healthy eardrums of the rats. Following incision, gelfoam soaked with HF hydrobromide of 30 mg/dl was applied on the perforation in study group, whereas gelfoam soaked with isotonic saline was applied on the perforation in control group. On days 1, 3, 7, 10, 14, 18, 21, 24, 27, and 30, otoendoscopic evaluation of eardrums under general anesthesia was conducted and perforations were screened. A rat of each group was killed in control days and TMs were dissected to evaluate histopathological changes. The average times for patency of perforation in study and control groups were 21.43 and 7.50 days, respectively. The difference was found to be statistically significant (p < 0.05). Histopathological evaluation revealed that HF reduces hyalinisation and fibrosis in eardrum, when compared with the control group. In conclusion, HF significantly delays closure time of myringotomies in rat model. However, this delay may not be enough for recovery of otitis media with effusion.

Roles of an anti-tuberculosis medication and surgery in patients with tuberculous otitis media

CONCLUSION

The standard treatment for tuberculous otitis media (TOM) without complications consists of anti-tuberculosis (anti-TB) medication, with which we experienced good treatment outcomes. However, surgery is required for recovery of anatomy and hearing function.

OBJECTIVE

To determine the clinical characteristics of TOM that might optimize diagnosis and to evaluate the differences in clinical courses between patients treated with and without surgery.

METHODS

We analyzed 14 patients (16 ears) who had been diagnosed and treated for TOM. Radiologic findings, laboratory data, and audiometry results were also evaluated. Patients were divided into a chemotherapy group and a surgery group according to treatment modality.

RESULTS

Temporal bone CT (TBCT) showed total occupation of the tympanic cavity by soft tissue and little evidence of ossicular erosion. In the chemotherapy group, dry ears were obtained in all but one patient (14 ears) after treatment. Normalized tympanic membrane (TM) was found in 50% in the chemotherapy group and in 75% in the surgery group. The air-bone gap (ABG) changed from 40.3 +/- 2.5 dB to 47.0 +/- 19.2 dB in the chemotherapy group and from 35.2 +/- 7.6 dB to 30.2 +/- 11.4 dB in the surgery group. After treatment, ABG improved by > 10 dB in one ear in the chemotherapy group and in four ears in the surgery group.

Are intratympanic injections of N-acetylcysteine and methylprednisolone protective against Cisplatin-induced ototoxicity?

OBJECTIVE

To identify and to compare the protective effect of intratympanic injections of N-acetylcysteine (NAC) or methylprednisolone to prevent cisplatin-induced ototoxicity, to investigate inner ear protection using an electron microscope and to evaluate the effect of 4% NAC on the middle ear.

DESIGN

Experimental study.

SETTING

Basic ear research center at Sainte-Justine hospital.

METHODS

Ten Hartley guinea pigs were divided into two groups, according to the product used intratympanically (4% NAC or 62.5 mg/mL methylprednisolone) in one ear. The other ear was left as control. Cisplatin was administered intraperitoneally (3 mg/kg), once a week for 5 weeks.

MAIN OUTCOME MEASURES

Auditory evoked brainstem responses were used to test hearing. The inner ear was screened using an electron microscope.

RESULTS

Significant threshold shift was seen on all tested frequencies of both groups. This difference is clinically and statistically significant in the methylprednisolone group. The NAC-treated group had a lower threshold shift than the methylprednisolone group in both ears. Electron microscope studies showed in all untreated-NAC ears severe lesion of the inner and outer hair cells with complete degeneration of steriocilia, whereas in NAC-treated ears we noted a nuclear and cytoplasmic membrane preservation with some preservation of steriocila. Also, 4% intratympanic NAC produces an external auditory canal and middle ear inflammatory reaction.

CONCLUSIONS

Intratympanic injections of methylprednisolone failed to demonstrate efficacy in protecting cisplatin ototoxicity whereas 4% NAC showed a partial protection. The safety of intratympanic injections should be investigated in further studies, as possible systemic shift of the locally administered treatment is suspected.

Effect of topical use of mitomycin C and 5-fluorouracil on the closure time of myringotomies created by radiofrequency unit

CONCLUSION

Both mitomycin C (MC) and 5-fluorouracil (5-FU) had a significant effect in prolonging the patency rate of radiofrequency myringotomy.

OBJECTIVE

To compare the effect of topical use of MC and 5-FU on the closure time of myringotomies created by a radiofrequency unit.

MATERIALS AND METHODS

Myringotomies were performed using a radiofrequency unit on 80 tympanic membranes of 40 rats. Rats were divided into two study groups and one control group. MC (0.4 mg/ml) and 5-FU (50 mg/ml) pledgets were applied topically in the right ears (study groups, 20 ears each) for 10 min and saline pledgets in the left ears (control group, 40 ears). Animals were monitored using otomicroscopy weekly and patency rates were recorded until myringotomy closure.

RESULTS

The mean patency times were 4.85 weeks for the MC group and 3.90 weeks for the 5-FU group. The mean patency rate for the control side was 1.30 weeks. The log-rank test revealed both study groups to have a significantly longer patency time than the control group (p<0.0001). Although the patency rate was found to be higher in the MC-treated group than the 5-FU-treated group, this difference was not statistically significant (p>0.05).

The effect of intraperitoneal administration of zinc aspartate on myringosclerosis in perforated tympanic membranes of rats

OBJECTIVES

The objective of the present study was to determine the effect of zinc aspartate on myringosclerosis in perforated rat tympanic membrane.

PATIENTS AND METHODS

Fifteen Sprague-Dawley rats were randomly divided into three groups each containing five rats. Automicroscopic examinations were performed and then all rats were bilaterally myringotomized. Group 1 received no treatment. Group 2 was treated with intraperitoneal injection of physiological saline and group 3 with intraperitoneal injection of zinc aspartate. Tympanic bullas were harvested after 20 days. Histopathological evaluation was carried out under the light microscope.

RESULTS

When the groups were compared in the light of the myringosclerotic findings, while there was no significant difference between group 1 and 2 (p=1.00), it was found that there were significant differences between group 1 and 3, and between group 2 and 3 (p<0.03).

CONCLUSION

It appears that zinc aspartat treatment has beneficial effects on prevention or retardation of the development of myringosclerosis, but further studies are needed to clarify this effect.

Does exogenous nitric oxide influence tympanosclerosis? An experimental study

OBJECTIVE

We aimed to elucidate the effects of exogenous nitric oxide application via myrigotomized rat tympanic membranes on tympanosclerosis.

MATERIALS AND METHODS

Forty male rats were included in the study. After myringotomy, nitric oxide was given to the left tympanic cavities and saline was given to the right as the control group. The procedure was repeated 3 times with weekly intervals. Three months after the first procedure, otomicroscopic examination was made and the rats were sacrificed for histologic examination.

RESULTS

Neither otomicroscopic examination, nor histologic examination of middle ears and tympanic membranes revealed any significant difference between the right and left sides. Tympanic membrane thicknesses were also similar on both sides without showing any significant difference.

CONCLUSIONS

Data from this study indicate that exogenous nitric oxide application did not change the occurence of tympanosclerosis in the rat model. Other cytokine interactions are needed to start the reaction sequence leading to tympanosclerosis.

Gentamicin is primarily localized in vestibular type I hair cells after intratympanic administration

Intratympanic (IT) gentamicin injections are effective in the control of episodic vertigo due to Ménière's disease. Histological studies in animals have found that the loss of type I vestibular hair cells far exceeds that of type II cells after IT gentamicin treatment. The objective of this study was to determine whether this selective toxicity for type I hair cells might be due to selective concentration of the drug by these cells. Gentamicin was localized within the vestibular epithelium by both direct and indirect methods. Gentamicin conjugated to Texas Red(R) was used as a direct tracer, and anti-gentamicin antibody provided an indirect means of localization. Conjugated or unconjugated gentamicin was injected into the left tympanic space of chinchillas. The animals were killed and fixed 1 or 3 weeks post-treatment. Confocal fluorescence microscopy was used to determine the localization of gentamicin in semicircular canal cristae. Results from the animals killed within 1 week of administration showed that numerous type I hair cells still remained throughout the epithelium. The mean intensity in grayscale units (0-255) of anti-gentamicin labeling for type I hair cells was 28.14 (95% CI 24.60-31.69), for type II hair cells was 17.09 (14.99-19.20), and for support cells was 5.35 (5.34-5.46; p < 0.001, ANOVA). Anti-gentamicin antibody labeling appeared in the majority of type I hair cells throughout their cytoplasm, but with greater intensity at the apex (p < 0.001). Intensity of fluorescence with Texas-Red conjugated gentamicin was 25.38 (22.83-27.94) in type I hair cells, 15.60 (14.73-16.48) in type II cells, and 12.62 (12.06-13.17) in support cells (p < 0.001, ANOVA). These results suggest that type I hair cells are more susceptible to gentamicin because they more avidly take up or retain the drug in the early period after administration.

Concentration gradient along the scala tympani after local application of gentamicin to the round window membrane

OBJECTIVES

The distribution of gentamicin along the fluid spaces of the cochlea after local applications has never previously been demonstrated. Computer simulations have predicted that significant basal-apical concentration gradients might be expected, and histologic studies indicate that hair cell damage is greater at the base than at the apex after local gentamicin application. In the present study, gradients of gentamicin along the cochlea were measured.

METHODS

A recently developed method of sampling perilymph from the cochlear apex of guinea pigs was used in which the samples represent fluid originating from different regions along the scala tympani. Gentamicin concentration was determined in sequential apical samples that were taken after up to 3 hours of local application to the round window niche.

RESULTS

Substantial gradients of gentamicin along the length of the scala tympani were demonstrated and quantified, averaging more than 4,000 times greater concentration at the base compared with the apex at the time of sampling. Peak concentrations and gradients for gentamicin varied considerably between animals, likely resulting from variations in round window membrane permeability and rates of perilymph flow.

CONCLUSIONS

The large gradients for gentamicin demonstrated here in guinea pigs account for how it is possible to suppress vestibular function in some patients with a local application of gentamicin without damaging auditory function. Variations in round window membrane permeability and in perilymph flow could account for why hearing losses are observed in some patients.

The effect of caffeic acid phenethyl ester on the prevention of experimentally induced myringosclerosis

OBJECTIVES

Myringosclerosis is a common sequela of ventilation tube insertion for the treatment of the otitis media with effusion. Several antioxidants have been identified to prevent myringosclerosis. The objective of this study was to investigate the effect of caffeic acid phenethyl ester (CAPE) on the prevention of experimentally induced myringosclerosis.

METHODS

Thirty-five Sprague-Dawley rats were unilaterally myringotomized. The rats were divided into four groups randomly: group 1 received no treatment, group 2 received intraperitoneally administered saline and group 3 received intraperitoneally administered CAPE. The tympanic membranes were examined by otomicroscopy on the 15th day after treatment. The membranes were then harvested and evaluated histologically by light microscopy.

RESULTS

The tympanic membranes from group 1 showed extensive myringosclerosis; those from group 2 showed a similar occurrence of myringosclerosis. However, group 3 had a reduced occurrence of myringosclerosis by otomicroscopic evaluation. Under light microscopic examination, the lamina propria of the pars tensa was found to be thicker and more sclerotic in groups 1 and 2 when compared with group 3.

CONCLUSIONS

Systemic treatment with CAPE was found to be effective in the prevention of sclerotic lesions in myringotomized rat tympanic membranes.

Tympanic Membrane Breakdown After Intratympanic Injection of Steroids in Irradiated Ears

OBJECTIVE

To describe a rare complication of intratympanic injection of steroids in susceptible ears.

PATIENTS

We present two patients with a history of irradiation involving the injected ear.

INTERVENTION

Therapeutic.

MAIN OUTCOME MEASURE

Tympanic membrane condition after intratympanic injection of steroids.

RESULTS

Total or near-total breakdown of the irradiated tympanic membrane.

CONCLUSION

Tympanic membranes with an impaired wound-healing ability, together with exposure to intratympanic steroids, may be at risk for total or near-total breakdown.

A novel dual inhibitor of calpains and lipid peroxidation (BN82270) rescues the cochlea from sound trauma

Free radical and calcium buffering mechanisms are implicated in cochlear cell damage that has been induced by sound trauma. Thus in this study we evaluated the therapeutic effect of a novel dual inhibitor of calpains and of lipid peroxidation (BN 82270) on the permanent hearing and hair cell loss induced by sound trauma. Perfusion of BN 82270 into the scala tympani of the guinea pig cochlea prevented the formation of calpain-cleaved fodrin, translocation of cytochrome c, DNA fragmentation and hair cell degeneration caused by sound trauma. This was confirmed by functional tests in vivo, showing a clear dose-dependent reduction of permanent hearing loss (ED50 = 4.07 microM) with almost complete protection at 100 microM. Furthermore, BN82270 still remained effective even when applied onto the round window membrane after sound trauma had occurred, within a therapeutic window of 24 h. This indicates that BN 82270 may be of potential therapeutic value in treating the cochlea after sound trauma.

Effects of Ciprofloxacin-Dexamethasone on Myringotomy Wound Healing

OBJECTIVE

To evaluate the effects of the ciprofloxacin-dexamethasone (CDX) combination ototopical treatment after myringotomy on tympanic membrane (TM) healing in ears with eustachian tube obstruction (ETO) and unobstructed ears.

STUDY DESIGN

Prospective, randomized, masked, controlled.

METHODS

ETO was created in the left ear of 30 rats to induce a model of otitis media with effusion (OME). After 3 weeks, bilateral myringotomy was performed (day 0). Animals were randomized into three groups to receive no treatment or bilateral once daily ototopical treatment with balanced salt solution (BSS, vehicle) or CDX for 13 days. Bilateral otomicroscopy was performed on days 7, 14, and 28. On day 14, five randomly selected animals per group were humanely euthanized and the TM harvested for histology. Three additional rats provided normal negative control ears for histologic comparisons.

RESULTS

On day 14, TM perforation healing rates were 100% in all ears of untreated and BSS-treated animals, 89% (8/9) in CDX-treated obstructed ears, and 30% (3/10) in CDX-treated unobstructed ears (P < .05 vs. BSS). On day 28, 100% (5/5) of the CDX-treated unobstructed ears and 80% (4/5) of the CDX-treated obstructed ears were healed. Histology showed initial TM thickening postmyringotomy in all ears but no significant qualitative differences between groups on day 28.

CONCLUSION

Myringotomy healing was transiently modulated by treatment with CDX but proceeded normally after CDX discontinuation. This early modulation might enhance middle ear drainage and middle ear concentrations of CDX when tympanostomy tube surgery is performed in patients with active OME and ETO, thus potentially reducing otorrhea and preventing or treating infection. It would not be expected to increase the risk of premature tube extrusion or adversely affect normal healing of the TM after usual spontaneous extrusion.

Low dose transtympanic gentamicin treatment for intractable Meniere's disease: a prospective study

OBJECTIVE

To evaluate the effectiveness of low dose transtympanic gentamicin treatment in Meniere's disease.

MATERIAL AND METHOD

Prospective study of 20 disable Meniere's patients in Ramathibodi Hospital who received transtympanic gentamicin treatment for Meniere's disease by fixed dose regimen of 12 injections during a period of 4 days. The study took place from March 1999 to December 2004. The hearing and equilibrium guidelines for reporting treatment results in Meniere's disease of the American Academy of Otolaryngology and Head & Neck Surgery (1995) were used. The outcomes of treatment were evaluated at the 6th month. The multivariate repeated measures ANOVA was used for statistical comparisons.

RESULTS

During the 5-year period, there were 20 patients, 9 men, and 11 women. The six-month outcomes of vertigo control, the functional level scale and tinnitus score were significantly improved by the treatment. Whereas, the mid frequency pure tone threshold average and the speech discrimination score were not significantly affected.

CONCLUSION

Fixed low dose transtympanic gentamicin treatment was found to be an effective treatment option for patients with disabling or intractable Meniere's disease, with a low incidence of hearing deterioration. The use of this method appears to be practical and has been set as the standard protocol replacing the vestibular surgery in Ramathibodi Hospital.

Effect of Intratympanic Application of Aminoglycosides on Click-Evoked Myogenic Potentials in Guinea Pigs

OBJECTIVES

Although numerous studies have identified damage to the cochlear and vestibular end organs as the primary site of aminoglycoside-induced ototoxicity, the effect on the saccule remains poorly understood, possibly due to lack of monitoring saccular function in experimental animals. Therefore, this study applied three kinds of aminoglycosides into the tympanic space of guinea pigs to examine their toxic impact on the saccule by way of click-evoked myogenic potential test coupled with morphologic assessment.

DESIGN

Albino guinea pigs were treated with saline, gentamicin, tobramycin, or amikacin, with 10 animals assigned to each group. Each compound was injected directly overlying but not through the round window membrane on the left ear, with the right ear serving as a control. One week after injection, each animal underwent auditory brain stem response, caloric test, and click-evoked myogenic potential test. Animals were then killed for morphologic assessment through the use of light and electron microscopic examinations.

RESULTS

The animals treated with saline, gentamicin, tobramycin, or amikacin exhibited abnormal auditory brain stem response in 0%, 30%, 100%, and 30% of cases; abnormal caloric responses were found in 0%, 100%, 40%, and 40% of cases; absent click-evoked myogenic potentials were found in 0%, 100%, 30%, and 40% of cases, respectively. Gentamicin and other groups differed significantly in abnormal rates of caloric responses and click-evoked myogenic potentials. Morphologic study of the gentamicin-treated animals confirmed that the absence of click-evoked myogenic potential originated from the lesion in the saccular macula.

CONCLUSIONS

Gentamicin represents the dominant susceptibility of aminoglycoside-induced vestibulotoxicity for eliminating both semicircular canal and saccular functions. This study further confirms the findings of human studies in which the caloric and vestibular evoked myogenic potentials responses were monitored to assess the abolition of vestibular function in patients treated with intratympanic gentamicin injection.

Healing of subacute tympanic membrane perforations in chinchillas treated with epidermal growth factor and pentoxifylline

HYPOTHESIS

The aims of the present study were to determine the effect of epidermal growth factor (EGF) and pentoxifylline on subacute tympanic membrane (TM) perforations and to quantify the healing rate of such perforations treated with these drugs alone or in combination.

BACKGROUND

It is known that EGF modulates in vitro and in vivo proliferation of epithelial and endothelial cells. Pentoxifylline is a methylxanthine that has been used to treat experimental skin flaps and venous leg ulcers. Data in the literature regarding this subject are contradictory, and quantitative data regarding the effects of EGF and pentoxifylline on TM perforation healing are scarce.

METHODS

We studied 50 chinchillas submitted to TM perforation. On postoperative Day 30, eight were selected for histologic analysis. Of the remaining 42, those presenting little or no healing were distributed into four groups: control, EGF, pentoxifylline, and EGF combined with pentoxifylline.

RESULTS

Histologic analysis showed that the observation period adopted was sufficient to consider the TM perforations subacute. We found significant differences between the study groups and the control group in the healing rate of subacute TM perforations during a 30-day period (analysis of variance; p < 0.001), which was 30.3% for the EGF group, 3.6% for the pentoxifylline group, 16.5% for the EGF-pentoxifylline group, and 8.7% for the control group.

CONCLUSIONS

The use of EGF promoted healing of subacute TM perforations in chinchillas, and the use of pentoxifylline did not. The combination of the two had no synergistic effect on the healing of these perforations.

Effectiveness of MeroGel hyaluronic acid on tympanic membrane perforations

CONCLUSIONS

Our results support the proposition that hyaluronic acid (HA) provides a moist wound-healing environment to aid in the healing process of tympanic membrane perforation. A single MeroGel administration can be effective as well as daily topical HA application in the treatment of tympanic membrane perforations. A single application of esterified HA may be more suitable for patients and also for otolaryngologists.

OBJECTIVE

The purpose of the present study was to evaluate the effectiveness of a single MeroGel application on traumatic tympanic membrane perforations in rats.

MATERIALS AND METHODS

The posterior quadrant of the tympanic membranes in both ears of 24 male pathogen-free Sprague-Dawley rats was perforated with a 20-gauge needle. Subjects were divided into two groups: MeroGel and daily topical HA-treated groups. All subjects were sacrificed and histopathological examinations of the tympanic bullas were carried out.

RESULTS

Perforations of controls, and MeroGel- and daily HA-treated groups closed in 17/24 (70.8%), 11/12 (91.7%), and 12/12 (100%) ears, respectively. There was a significant difference between control and MeroGel-treated groups, and also between control and daily topical HA-treated groups for the presence of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), lymphocytes and collagen fibrils (p<0.05), whereas there was no significant difference between MeroGel- and daily topical HA-treated groups (p>0.05).

Effects of tumor necrosis factor alpha antagonist, platelet activating factor antagonist, and nitric oxide synthase inhibitor on experimental otitis media with effusion

OBJECTIVES

We studied the inflammatory responses in otitis media with effusion induced by lipopolysaccharide (LPS) in rats, and compared the preventive effects of tumor necrosis factor (TNF) soluble receptor type I (sTNFRI, a TNF-alpha antagonist), platelet activating factor antagonist, and the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME).

METHODS

We used 2 control groups of Sprague Dawley rats (untreated and saline-treated) and 4 experimental groups, which all received an intratympanic injection of LPS, followed in 3 groups by experimental treatment of the same ear. The LPS group had no additional treatment. The L-NAME group received intraperitoneal injection of L-NAME and was reinjected after 12 hours. The A-85783 group was first given an intraperitoneal injection of A-85783. The sTNFRI group was first given an intratympanic injection of sTNFRI. Twenty-four hours after the initial intratympanic injection of LPS, temporal bones from each group were examined histopathologically and the vascular permeability of the middle ear mucosa was measured by Evans blue vital dye staining.

RESULTS

The L-NAME, A-85783, and sTNFRI groups showed significantly reduced capillary permeability, subepithelial edema, and infiltration of inflammatory cells in comparison with the LPS group. There were no differences in capillary permeability, subepithelial edema, or infiltration of inflammatory cells between the A-85783 and sTNFRI groups. The L-NAME group showed no difference in vascular permeability or subepithelial edema in comparison with the A-85783 and sTNFRI groups, but showed more infiltration of inflammatory cells.

CONCLUSIONS

We conclude that sTNFRI, A-85783, and L-NAME can be proposed as alternative future treatments for otitis media with effusion. However, L-NAME may be the least effective of these agents.

Local perfusion of the tumor necrosis factor alpha blocker infliximab to the inner ear improves autoimmune neurosensory hearing loss

OBJECTIVE

To evaluate the effect of transtympanic administration of tumor necrosis factor alpha (TNF-alpha) blockers to patients suffering from autoimmune inner ear disease (AIED).

STUDY DESIGN

Nonrandomized, prospective pilot study.

SETTING

Tertiary referral center.

PATIENTS

9 patients (4 men and 5 women; aged 51.22 +/- 13.11 years) presenting with autoimmune sensorineural hearing loss who responded to oral steroid treatment. Two groups of patients were treated. Group A consisted of 5 patients with AIED who could not be tapered off steroids. Group B consisted of 4 patients who were treated with intratympanic anti-TNF-alpha antibody therapy alone after a relapse of hearing loss following discontinuation of steroids.

INTERVENTION

A Silverstein MicroWick local delivery system was placed in the round window niche and the patients were treated for 4 weeks with a weekly infusion of infliximab, a monoclonal antibody against TNF-alpha.

MAIN OUTCOME MEASURE(S)

Evaluation of hearing thresholds at 250-8000 Hz was performed before and after implantation of the Silverstein MicroWick and local delivery of the TNF-alpha blocker.

RESULTS

Local administration of the TNF-alpha blocker allowed methylprednisolone to be tapered off without loss of hearing function in 4/5 steroid-dependent patients. Four additional patients were treated only with anti-TNF-alpha perfusion to the round window membrane without concomitant systemic administration of methylprednisolone. In 3 of these 4 patients, the pure tone average improved to 22.6 +/- 15.7 dB, resulting in hearing recovery comparable to treatment with systemic methylprednisolone. The 7 responding patients showed a significant reduction of recurrence of hearing loss to 0.028 +/- 0.072 episodes per month over the 4.3 +/- 2.4 months of the post-treatment period compared to 0.84 +/- 0.4 recurrences per week seen in the pretreatment period.

CONCLUSIONS

The results of this pilot trial demonstrate that in patients with AIED, transtympanic delivery of the TNF-alpha blocker infliximab once weekly for 4 weeks allowed steroids to be tapered off, resulted in hearing improvement and reduced disease relapses. These preliminary efficacy and safety results appear encouraging enough to warrant further follow-up and studies for better determination of the potential clinical utility of local administration of infliximab for autoimmune hearing loss.

The Anti-Oxidant Effect of Alpha-Tocopherol in the Prevention of Experimentally Induced Myringosclerosis

HYPOTHESIS

The objective of this study was to investigate the possible effect of alpha-tocopherol on the prevention of experimentally induced myringosclerosis.

BACKGROUND

Myringosclerosis is a common sequela of ventilation tube treatment of otitis media with effusion. The relationship between oxygen-derived free radicals and occurrence of myringosclerosis has been proven in experimental models, and it was also shown that the formation of myringosclerosis after experimental myringotomy could be reduced by application of various free radical scavengers.

METHODS

Eighteen Wistar albino rats were myringotomized on the left side and randomly separated into two groups: group A consisted of rats which received intramuscular alpha-tocopherol injections 100 mg/kg daily and group B which were injected with physiological serum only. The occurrence of myringosclerotic plaques in the tympanic membranes of the two groups was compared by otomicroscopy, histopathology, and tympanometry, which is a novel method of quantification. Blood samples were collected for biochemical evaluation, and the tympanic membranes were harvested on the 15th day of the experiment.

RESULTS

In otomicroscopic evaluation, tympanic membranes in group B revealed varying degrees of myringosclerotic plaques; on the other hand, tympanic membranes in group A showed faint or no existence of myringosclerosis. The mean malondialdehyde levels were 1.33 +/- 0.11 micromol/L in group A and 7.49 +/- 1.37 micromol/L in group B (Z = -1.906, p = 0.057). In all ears from group B, the magnitude of the maximum admittance measured by tympanometry reduced to approximately 40% of the values obtained from group A (Z = -2,160, p = 0.031). The mean magnitude of the maximum admittance from group A was very close to the standardization values of Wistar albino rats, which predicts a functional outcome.

CONCLUSION

The formation of myringosclerosis after experimental myringotomy can be diminished by intramuscular alpha-tocopherol injections.

Long-term follow-up after gentamicin application via the Silverstein MicroWick in the treatment of Ménière's disease

We conducted a retrospective study to evaluate the long-term effectiveness of gentamicin applied directly to the round window membrane via the Silverstein MicroWick system in patients with definite or probable Ménière's disease. The study population was made up of 69 patients who had received 3 drops of gentamicin 10 mg/ml three times daily; the duration of treatment was guided by objective data obtained from weekly electronystagmography and audiometry. Relief of vertigo was assessed by chart review and telephone interviews. After a minimum follow-up of 24 months, we found that vertiginous symptoms remained controlled in 53 patients (76.8%) after one or more courses of drug therapy. A single course of treatmentwas successful in 41 patients (59.4%). We conclude that long-term control of vertigo can be achieved inpatients with Ménère's disease by direct application of gentamicin to the round window membrane via the Silverstein MicroWick. This minimally invasive self-treatment technique was well tolerated and free of long-term complications.

The effect of Vitamin E treatment on the development of myringosclerosis after ventilation tube insertion

OBJECTIVES

Recent studies have established the relationship between the reactive oxygen species and myringosclerosis. Furthermore several antioxidants have been known to prevent myringosclerosis. All the previous studies supporting this hypothesis have been performed on animals. The aim of our study is to investigate the possible effect of Vitamin E on the development of tympanosclerosis after VT insertion on human subjects.

METHODS

72 children undergoing myringotomy and VT insertion were included in the study. Vitamin E was applied to the right ear and no treatment was applied to the left ear. Both ears were examined at the end of 9 months with otomicroscopy. Myringosclerosis formation at the end of the study period was noted for each ear.

RESULTS

Myringosclerosis was found in 33 of the 144 ears. The overall incidence was 22.9%. While 22 (30.6%) of the 72 left ears showed myringosclerosis otomicroscopically, in only 11 (15.3%) of the 72 right ears that were treated with Vitamin E was myringosclerosis observed at the end of the study period. Of these nine cases were bilateral.

CONCLUSION

Animal studies have well documented the development of myringosclerosis after myringotomy and VT insertion and beneficial effects of different antioxidants. Our study has shown similar results in human subjects. Further clinical studies consisting of a larger patient population are needed to bring about routine clinical use of antioxidants in myringotomy and VT insertion.

A comparison of 5 days of therapy with cefdinir or azithromycin in children with acute otitis media: a multicenter, prospective, single-blind study

BACKGROUND

Short-course therapy for acute otitis media (AOM) improves adherence and may reduce secondary bacterial resistance.

METHODS

In this multicenter, prospective, investigator-blinded study, patients between the ages of 6 months and 6 years with a clinical diagnosis of AOM were randomized to receive cefdinir oral suspension 7 mg/kg q12h for 5 days or azithromycin oral suspension 10 mg/kg once daily on day 1 and 5 mg/kg once daily on days 2 through 5. Clinical response was assessed at the end-of-therapy (EOT) visit (days 7-9) and the follow-up visit (days 20-25).

RESULTS

Three hundred fifty-seven patients were enrolled in the study. The treatment groups were similar at baseline with respect to demographic characteristics (mean [SD] age, 3.0 [1.7] years; 55% male), incidence of bilateral AOM (45%), and presenting signs and symptoms. The majority of evaluable children (77%) had previously received conjugated heptavalent pneumococcal vaccine (PCV7) against Streptococcus pneumoniae. At the EOT visit, clinical cure rates were comparable for cefdinir and azithromycin (87% [151/174] and 85% [149/176], respectively; 95% CI, -5.5 to 9.8). In addition, clinical cure rates at the EOT visit in the children who had been vaccinated with PCV7 were comparable between cefdinir and azithromycin (86% vs 83%; 95% CI, -6.5 to 11.8). No significant difference in clinical cure rates was observed at the follow-up visit (76% and 86%; 95% CI, -18.9 to 0.0). Parental satisfaction was similar between treatment groups with regard to ease of use, taste, compliance, health care resource utilization, and missed days of work and day-care. Both antibiotics were well tolerated; diarrhea and abnormal stools were the most common antibiotic-related adverse events (< or = 7% each).

CONCLUSIONS

Short courses (5 days) of therapy with cefdinir or azithromycin were comparable in these children with AOM based on clinical end points, parental preferences, and health care utilization.

Intratympanic Dexamethasone Injection for Refractory Sudden Sensorineural Hearing Loss

OBJECTIVE

This case-control study aimed to analyze the effect of intratympanic dexamethasone injection (ITDI) as a treatment option for patients with sudden sensorineural hearing loss (SSNHL) who were refractory to classic oral steroid treatment.

METHODS

Sixty-six patients with SSNHL, who were refractory to a course of oral steroid therapy, were included in this study. We prospectively treated consecutive 33 patients (34 ears) with ITDI from August 2002 to January 2004. We then retrospectively collected data from age- and sex-matched previous patients who did not take any more treatments after the initial regimen between March 2000 and July 2002. ITDI was performed in the supine position on four separate occasions over the course of 2 weeks. Hearing was assessed immediately before every injection and at 1 week after therapy. Hearing improvement was defined as more than 10 dB in pure-tone average (PTA).

RESULTS

Hearing improvement was observed in 13 (39.4%) of 33 patients who underwent ITDI and in two (6.1%) of 33 patients in the control group. Five of 13 represented hearing improvement over than 20 dB in PTA, and 11 of 20 patients, who showed no improvement in PTA by ITDI, showed improvement over 10 dB in some frequencies. There were no definite prognostic factors between the patients who responded to ITDI and those who did not.

CONCLUSION

ITDI may be a simple and effective therapy for patients with refractory SSNHL.

Vitamin e-coated tympanostomy tube insertion decreases the quantity of free radicals in tympanic membrane

OBJECTIVE

Tympanosclerosis is a common sequela of ventilation tube treatment of otitis media with effusion causing hearing disability. It is associated with an increased production of free radicals (also known as reactive oxygen species) after myringotomy. Vitamin E is a scavenger of different free radicals by working as an antioxidant. The aim of the present study was to evaluate the effect of vitamin E-coated tympanostomy tube insertion at quantity of free radicals in rat tympanic membrane.

METHODS

This prospective, controlled animal study consisted of male Sprague-Dawley rats divided into two groups of 10 animals each. Ordinary silcone tubes were applied to the right ears of the first group and vitamin E-coated silcone tubes were applied to the right ears of the second group. The left ears were used as controls. Then, the animals were killed and chemiluminescence measurements were made for tympanic membranes.

RESULTS

Reactive oxygen species levels (ROS) were significantly increased in right ears of the first group when compared with the control ears (P < .0001), and the levels were statistically significant decreased in right ears of the second group as compared with the operated ears of the first group (P < .0001). The free radical levels of right and left ears in the second group were similar.

CONCLUSIONS

Our results indicate that vitamin E-coated tube insertion decreases the quantity of reactive oxygen species in tympanic membrane after myringotomy and tympanostomy tube insertion.

Topical Application of Mitomycin C before versus after Myringotomy: An Experimental Study

The objective of this animal study was to compare topical mitomycin C (MMC) before and after nonlaser myringotomy. Bilateral myringotomies were performed in 12 rats. On the left side, MMC was applied to the intact tympanic membrane for 10 min before myringotomy (preapplication group). On the right side, MMC was applied to the tympanic membrane following myringotomy. Tympanic membranes were observed for a total of 8 weeks. By day 35, all myringotomies with application of MMC after perforation of the tympanic membrane were closed, whereas 42% of the myringotomies with application of MMC prior to perforation remained patent. One tympanic membrane in the preapplication group showed an enlargement of the perforation with partial destruction of the malleus. The present study showed that the application of MMC to the intact tympanic membrane prolongs the patency of nonlaser myringotomies in rats. Specific side effects of the MMC application must be kept in mind.