A comparison between endoscopic and microscopic approaches for stapes surgery: a systematic review.

OBJECTIVES: To evaluate the surgical techniques, approaches, audiological outcomes and complications of endoscopic stapes surgery. METHODS: Systematic searches of the literature were performed in PubMed, Web of Science and Scopus databases, to identify studies of patients who underwent stapes surgery using endoscopic approaches and studies reporting objective post-operative hearing outcomes. The following information was extracted: surgery duration, complications, surgical technique and audiometric results. RESULTS: Fourteen studies were selected for appraisal, which included a total of 282 ears subjected to endoscopic stapes surgery. Endoscopic stapes surgery seems to provide adequate visualisation of the middle-ear structures, thereby allowing less invasive surgery and potentially equivalent audiological outcomes as compared with a traditional microscopic approach. Other advantages of endoscopic stapes surgery include decreased surgery time, a reduced need for drilling, and auditory results comparable to those of microscopic techniques. CONCLUSION: Studies have shown that endoscopic stapes surgery has similar surgical and functional advantages as compared with microscopic surgery.

The pathogens profile in children with otitis media with effusion and adenoid hypertrophy.

OBJECTIVES: To evaluate the presence of viruses and bacteria in middle ear and adenoids of patients with and without otitis media with effusion (OME). METHODS: Adenoid samples and middle ear washes (MEW) were obtained from children with OME associated with adenoid hypertrophy undergoing adenoidectomy and tympanostomy, and compared to those obtained from patients undergoing cochlear implant surgery, as a control group. Specific DNA or RNA of 9 respiratory viruses (rhinovirus, influenza virus, picornavirus, syncytial respiratory virus, metapneumovirus, coronavirus, enterovirus, adenovirus and bocavirus) and 5 bacteria (S. pneumoniae, H. influenzae, M. catarrhalis, P. aeruginosa and S. aureus) were extracted and quantified by real-time PCR. RESULTS: 37 OME and 14 cochlear implant children were included in the study. At the adenoid, virus and bacteria were similarly detected in both OME and control patients. At the middle ear washes, however, a higher prevalence of bacteria was observed in patients with OME (p = 0.01). S. pneumoniae (p = 0.01) and M. catarrhalis (p = 0.022) were the bacteria responsible for this difference. Although total virus detection was not statistically different from controls at the middle ear washes (p = 0.065), adenovirus was detected in higher proportions in adenoid samples of OME patients than controls (p = 0.019). CONCLUSIONS: Despite both OME and control patients presented similar rates of viruses and bacteria at the adenoid, children with OME presented higher prevalence of S. pneumonia, M. catarrhalis in middle ear and adenovirus in adenoids when compared to controls. These findings could suggest that these pathogens could contribute to the fluid persistence in the middle ear.

Mechanisms of cisplatin ototoxicity: theoretical review.

INTRODUCTION: Cisplatin is an effective chemotherapeutic agent commonly used in the treatment of malignant tumours, but ototoxicity is a significant side effect. OBJECTIVES: To discuss the mechanisms of cisplatin ototoxicity and subsequent cell death, and to present the results of experimental studies. MATERIAL AND METHODS: We conducted a systematic search for data published in national and international journals and books, using the Medline, SciELO, Bireme, LILACS and PubMed databases. RESULTS: The nicotinamide adenine dinucleotide phosphate oxidase 3 isoform (also termed NOX3) seems to be the main source of reactive oxygen species in the cochlea. These reactive oxygen species react with other molecules and trigger processes such as lipid peroxidation of the plasma membrane and increases in expression of the transient vanilloid receptor potential 1 ion channel. CONCLUSION: Cisplatin ototoxicity proceeds via the formation of reactive oxygen species in cochlear tissue, with apoptotic cell death as a consequence.

Histological effects of intratympanic gentamicin on the vestibular organ of guinea pigs.

BACKGROUND: Transtympanic administration of gentamicin may be suitable to achieve unilateral vestibular ablation, in order to control unilateral Ménière's disease. In low doses, gentamicin appears to affect selectively the vestibular system, with relative sparing of the cochlea. An experimental study on guinea pigs was conducted to determine what single dose of gentamicin would produce a unilateral vestibular organ lesion when applied to the middle ear. STUDY DESIGN: Experimental and prospective. METHODS: Four groups of guinea pigs received different gentamicin doses (1, 5, 10 and 25 mg) administered to the middle ear. The animals' vestibular organs were then assessed by scanning electron microscopy, in order to quantify the level of vestibular damage. RESULTS: Study of the utricular macula and the ampullar crista of the lateral semicircular canal revealed vestibular neuroepithelial lesions in all infused ears. CONCLUSIONS: The severity of the vestibular neuroepithelial lesions was dose-dependent. Lower gentamicin doses were observed to damage vestibular structures more than cochlear structures.

Spontaneous reversibility of damage to outer hair cells after sodium salicylate induced ototoxicity.

BACKGROUND: High sodium salicylate doses can cause reversible hearing loss and tinnitus, possibly due to reduced outer hair cell electromotility. Sodium salicylate is known to alter outer hair cell structure and function. This study determined the reversibility and cochlear recovery time after administration of an ototoxic sodium salicylate dose to guinea pigs with normal cochlear function. STUDY DESIGN: Prospective experimental investigation. METHODS: All animals received a single 500 mg sodium salicylate dose, but with different durations of action. Function was evaluated before drug administration and immediately before sacrifice. Cochleae were processed and viewed using scanning electron microscopy. RESULTS: Changes in outer hair cell function were observed to be present 2 hours after drug administration, with recovery of normal anatomy beginning after 24 hours. Subsequently, derangement and distortion of cilia reduced, with effects predominantly in row three. At 168 hours, cilia were near-normal but with mild distortions which interfered with normal cochlear physiology. CONCLUSIONS: Ciliary changes persisted for up to 168 hours after ototoxic sodium salicylate administration.