The role of CT angiography and endovascular treatment in acute-massive head and neck bleeding.

PURPOSE: To report the results of the endovascular treatment of acute-massive head and neck bleeding in a single center and underline the value of computerized tomography-angiography and endovascular treatment of this desperate patient group. METHODS: Forty-eight patients who suffered from acute-massive head and neck bleeding and in whom conservative treatment options had failed were included in the study. To localize the site of the bleeding, computerized tomography-angiography was obtained above the supra-aortic level. Depending on the type and site of bleeding, an urgent angiographic evaluation and appropriate endovascular treatment procedure were performed in the same session immediately. Complete control of all active bleeding was determined as "technical success" at the end of the procedure. RESULTS: The majority of the endovascular treatment indications were tumoral mass bleedings in this study. Eight patients, all of which had head and neck tumors as the cause of the bleeding underwent repeated interventional procedures due to acute re-bleeding. All patients left the angiography unit with technical success and dramatic clinical improvement. Two patients had procedure-related severe complications, such as contrast-induced nephropathy and acute cerebrovascular accident. One patient died due to massive re-bleeding during the follow-up period. CONCLUSION: Computerized tomography-angiography is a successful imaging method to reveal the location and cause of bleeding. Endovascular treatment of acute-massive head and neck bleeding is an effective and life-saver treatment option that can be used successfully with relatively low-risk potential.

Change in gene expression levels of GABA, glutamate and neurosteroid pathways due to acoustic trauma in the cochlea.

The characteristic feature of noise-induced hearing loss (NIHL) is the loss or malfunction of the outer hair cells (OHC) and the inner hair cells (IHC) of the cochlea. 90-95% of the spiral ganglion neurons, forming the cell bodies of cochlear nerve, synapse with the IHCs. Glutamate is the most potent excitatory neurotransmitter for IHC-auditory nerve synapses. Excessive release of glutamate in response to acoustic trauma (AT), may cause excitotoxicity by causing damage to the spiral ganglion neurons (SGN) or loss of the spiral ganglion dendrites, post-synaptic to the IHCs. Another neurotransmitter, GABA, plays an important role in the processing of acoustic stimuli and central regulation after peripheral injury, so it is potentially related to the regulation of hearing function and sensitivity after noise. The aim of this study is to evaluate the effect of AT on the expressions of glutamate excitotoxicity, GABA inhibition and neurosteroid synthesis genes.We exposed 24 BALB/c mice to AT. Controls were sacrificed without exposure to noise, Post-AT(1) and Post-AT(15) were sacrificed on the 1st and 15th day, respectively, after noise exposure. The expressions of various genes playing roles in glutamate, GABA and neurosteroid pathways were compared between groups by real-time PCR.Expressions of Cyp11a1, Gls, Gabra1, Grin2b, Sult1a1, Gad1, and Slc1a2 genes in Post-AT(15) mice were significantly decreased in comparison to control and Post-AT(1) mice. No significant differences in the expression of Slc6a1 and Slc17a8 genes was detected.These findings support the possible role of balance between glutamate excitotoxicity and GABA inhibition is disturbed during the post AT days and also the synthesis of some neurosteroids such as pregnenolone sulfate may be important in this balance.

Transorbital endoscopic approaches to the skull base: a systematic literature review and anatomical description.

Transorbital endoscopic approaches are increasing in popularity as they provide corridors to reach various areas of the ventral skull base through the orbit. They can be used either alone or in combination with different approaches when dealing with the pathologies of the skull base. The objective of the current study is to evaluate the surgical anatomy of transorbital endoscopic approaches by cadaver dissections as well as providing objective clinical data on their actual employment and morbidity through a systematic review of the current literature. Four cadaveric specimens were dissected, and step-by-step dissection of each endoscopic transorbital approach was performed to identify the main anatomic landmarks and corridors. A systematic review with pooled analysis of the current literature from January 2000 to April 2020 was performed and the related studies were analyzed. Main anatomical landmarks are presented based on the anatomical study and systematic review of the literature. With emphasis on the specific transorbital approach used, indications, surgical technique, and complications are reviewed through the systematic review of 42 studies (19 in vivo and 23 anatomical dissections) including 193 patients. In conclusion, transorbital endoscopic approaches are promising and appear as feasible techniques for the surgical treatment of skull base lesions. Surgical anatomy of transorbital endoscopic approaches can be mastered through knowledge of a number of anatomical landmarks. Based on data available in the literature, transorbital endoscopic approaches represent an important complementary that should be included in the armamentarium of a skull base team.

Skull base osteomyelitis: clinical and radiologic analysis of a rare and multifaceted pathological entity.

Skull base osteomyelitis (SBO) is a potentially life-threatening inflammation of cranial base bony structures of variable origin. Criteria for diagnosis and treatment are still controversial. Demographics, predisposing factors, symptoms, imaging, and clinical, laboratory, histological, and microbiological data of patients managed for SBO at the University Hospital of Brescia (ASST Spedali Civili) between 2002 and 2017 were retrospectively reviewed. Patients were included in different etiological groups. The topographic distribution of magnetic resonance (MR) abnormalities was recorded on a bi-dimensional model of skull base, on which three different patterns of inflammatory changes (edematous, solid, or necrotic) were reported. In patients with a history of radiotherapy, the spatial distribution of SBO was compared with irradiation fields. The association between variables and etiological groups was verified with appropriate statistical tests. A classification tree analysis was performed with the aim of inferring a clinical-radiological diagnostic algorithm for SBO. The study included 47 patients, divided into 5 etiological groups: otogenic (n = 5), radio-induced (n = 16), fungal (n = 14), immune-mediated (n = 6), and idiopathic (n = 6). At MR, five types of topographical distribution were identified (central symmetric, central asymmetric, orbital apex, sinonasal, maxillary). In patients with a history of radiotherapy, the probability to develop SBO was significantly increased in areas receiving the highest radiation dosage. The analysis of patients allowed for design of a classification tree for the diagnosis of SBO. The integration of clinical and radiologic information is an efficient strategy to categorize SBO and potentially guide its complex management.

The role of CD133 expression of cancer stem cells on radiotherapy response in early stage glottic cancers.

PURPOSE: To investigate the relationship between CD133 positivity and radiotherapy (RT) response in early stage glottic laryngeal cancers. METHODS: Thirty seven patients with early-stage glottic laryngeal carcinoma who were treated with primary RT were evaluated. Patients with regular follow-up of at least 3 years were included in the study. Patients who had previously received chemotherapy for laryngeal surgery or underwent surgery were excluded. The patients were divided into two groups as recurrent and non-recurrent. These two groups were compared in terms of CD133 expression by immunohistochemical method. RESULTS: There were 37 patients in the study. Ten patients had recurrence and seven (70%) had CD133 positive and three had CD133 negative. Of 27 patients who had no recurrence, 16 (59%) had CD133 positive and 11 (41%) had CD133 negative. 7 (70%) of ten patients with recurrence were found to be positive for CD133; There was no statistically significant difference between recurrent and non-recurrent patient groups in terms of CD133 positivity (p > 0.05). There was no correlation between the final CD133 score and recurrence status as well (p > 0.05). CONCLUSION: There was no relationship between radiotherapy response and CD133 staining in early-stage glottic laryngeal cancers. It is the largest study about CD133 and RT sensitivity in early stage glottic carcinomas.

Evaluation of the effect of inferior turbinate outfracture on nasolacrimal transit time by saccharin test.

AIM: To evaluate the effect of inferior turbinate outfracture on nasolacrimal transit time by saccharin test. MATERIALS AND METHODS: Twenty patients who underwent septoplasty + unilateral radiofrequency ablation and outfracture of inferior turbinate were enrolled into study. They had no complaints about their eyes and denied previous ocular surgery. Their nasolacrimal saccharin transit times (NSTTs) were estimated preoperatively and postoperatively in the 1st and 2nd months. The non-fractured side eye was measured only once preoperatively. The fractured-side eye was measured three times. These times were compared statistically. RESULTS: There were 8 men and 12 women. Mean age was 29.04. Killian incision was used in 14 and hemitransfixion incision was used in 6 patients. Median NSTT was 484, 461, 490 and 446 s for the non-fracture side, preoperatively and postoperatively in the 1st and 2nd months, respectively. There was no statistically significant difference between the two eyes preoperatively, and in the fractured side preoperatively and postoperatively in the 2nd month. There were significant differences between median NSTT in postoperative 1st month and median NSTT in the preoperative measure, and between postoperative 1st and 2nd months (p < 0.05). Median NSST in the 1st month was longer than the others. CONCLUSION: Outfracture of inferior turbinate had no permanent effect on NSTT 2 months after surgery in patients that had a healthy nasolacrimal system.

The effect of FoxP3 on tumour stage, treatment response, recurrence and survivalability in nasopharynx cancer patients.

OBJECTIVES: To investigate the relationship between the cell percentage of T regulator (Treg) cells of patients' specimens and disease severity, survivability, recurrence and metastasis in patients who were diagnosed with nasopharyngeal carcinoma (NPC). DESIGN, SETTING AND PARTICIPANTS: Sixty patients who were diagnosed as NPC and treated by the same protocol were enrolled to the study. Patient files were reviewed retrospectively and their clinical and pathological results were recorded. Deparaffinized samples of nasopharyngeal carcinoma patients were stained immunohistochemically with anti-FoxP3 monoclonal antibody. All patients's Anti-FoxP3 stained slides were evaluated by the same pathologist. Stained Treg lymphocytes around the tumoral foci were investigated. Patients were divided into two groups according to the total anti-FoxP3-stained Treg cell counts of the specimens; that is, less than 20% of the total or more than 20% of the total. These groups were compared statistically. MAIN OUTCOME MEASURES: Intensity of FoxP3 which is related to negative tumor response was the main outcome measure. It was evaluated in terms of stage, survival, recurrence and metastasis. RESULTS: The study group consisted of 42 male patients (70%) and 18 female patients (30%). The mean age was 47 ± 14.9. NPC subtypes among the patients were undifferentiated non-keratinized type in 54 patients (90%), differentiated non-keratinized type in 4 patients (6.66%) and keratinized type squamous cell carcinoma (SCC) in 2 patients (3.33%). When the two groups were compared in terms of pathological subtype, there was no significant variation between the two groups. There was also no significant variation between the two groups when compared on the basis of tumor stage (P = 0.36 for T phase, P = 0.122 for N phase), early stage, late phase (P = 0.15), survival rate (P = 0.69 for general survival), recurrence (P = 0.2 for local recurrence, P = 0.37 for regional recurrence) and distant metastasis (P = 0.3). CONCLUSION: There was no significant relationship between the concentration of these cells in the stained specimens and the disease stage, survival rate, recurrence and distant metastasis discovered.

Preventing amikacin related ototoxicity with N-acetylcysteine in patients undergoing peritoneal dialysis.

Amikacin is a frequently used antibiotic in the treatment of peritoneal dialysis (PD)-related peritonitis. Ototoxicity is a well-known complication of amikacin for which increased oxidative stress and free oxygen radicals are thought to be responsible. In this study, the effect of N-acetyl-cysteine (NAC) on cochlear function and oxidant situation in the amikacin related ototoxicity in PD-related peritonitis patients are investigated. Forty-six patients who had their first PD-related peritonitis attacks receiving empirical amikacin treatment were enrolled in the study. The patients were randomized into two groups; the first group (n = 23) as NAC receiving and the second group (n = 23) as a placebo receiving, control group. Otoacoustic emissions were measured before, 1 week after and 4 weeks after the treatment. Oxidative stress measurements were performed concurrently in order to evaluate the effectiveness of NAC. The results of screening with otoacoustic emission testing after amikacin treatment showed that cochlear function is protected especially in higher frequencies in NAC group when compared with the control group. Evaluation of the antioxidant status of the two groups showed no differences in the basal values, but at the first week there was an increase in the NAC group compared with the control group, and this increase became significant at the fourth week. NAC is found to be safe and effective in amikacin-related ototoxicity in patients with PD-related peritonitis. We suggest a close monitoring of the patients receiving amikacin containing treatment protocols and if amikacin is administrated supplementing the treatment with NAC.

Comparative Analysis of Lateral Pharyngoplasty and Uvulopalatopharyngoplasty Techniques With Polisomnography and Epworth Sleepiness Scales.

Snoring is caused by the vibration of structures of the oral cavity, such as the soft palate, uvula, tonsils, base of the tongue, epiglottis, and lateral pharyngeal walls. When these structures collapse and obstruct the airway, apnea occurs. Obstructive sleep apnea syndrome (OSAS) is characterized by repeated periods of upper airway obstruction, a decrease in arterial oxygen saturation, and interrupted sleep. The prevalence of OSAS is 1% to 5% in men and 1.2% to 2.5% in women. Crucial factors in deciding the surgical approach include a detailed ear-nose-throat examination, Muller maneuver, sleep endoscopy, and apnea hypopnea index scores. Accepted treatments include continuous positive airway pressure (CPAP), surgeries of the base of the tongue and/or palate, and multi-level surgeries. It, however, is important to continue to evaluate the efficacies of such procedures. The authors evaluated the outcomes of 23 patients who underwent surgery for OSAS, using preoperative and postoperative polysomnography (PSG) and the Epworth sleepiness scale (ESS). The results were compared before and after surgery. In all, 14 patients had lateral pharyngoplasty and 9 had uvulopalatopharyngoplasty (UPPP). The PSG and Epworth scale values were significantly lower in both groups, postoperatively. Patients indicated that their quality of life had improved. In conclusion, the surgeries were successful. In line with the literature, our results indicate that lateral pharyngoplasty and UPPP can be used in appropriate patients. Longer-term studies on more patients will provide more detailed information in the future.

The Depth of Invasion and Level IV Cervical Node Metastasis in Patients with Clinically N0 Tongue Cancer.

BACKGROUND: The accurate indication for level IV dissection is crucial for preventing complications such as phrenic nerve damage and chylous fistulas in clinically N0 tongue cancer. Although the depth of invasion is an established independent risk factor for occult lymph node metastasis in tongue cancer, its relationship with level IV metastasis has not been evaluated. This study investigated the relationship between the depth of invasion and level IV nodal metastasis in clinically N0 tongue cancer. METHODS: We retrospectively investigated clinical N0 patients who underwent glossectomy and level I-IV neck dissection. We examined lymph node metastasis, risk factors, and the relationship between depth of invasion and metastasis. RESULTS: Our study included 58 patients, and no patient had isolated level IV metastasis. Additionally, there was no level IV metastasis in well-differentiated tumors. Tumor size, depth of invasion, differentiation, and perineural invasion were significantly associated with level IV neck metastasis. We found a critical tumor size of 2.5 cm and depth of invasion of 8 mm for level IV neck metastasis. CONCLUSION: Based on our findings, we recommend that level IV dissection should be considered for poorly differentiated tumors, tumors greater than 2.5 cm in size, and those deeper than 8 mm. This study highlights the importance of depth of invasion as a prognostic factor for predicting level IV metastasis and suggests that our findings can be used to prevent unnecessary level IV dissections that may lead to complications in tongue cancer surgery.

Intraoperative surgical navigation as a precision medicine tool in sinonasal and craniofacial oncologic surgery.

INTRODUCTION: Recent evidence supports the efficacy of surgical navigation (SN) in improving outcomes of sinonasal and craniofacial oncologic surgery. This study aims to demonstrate the utility of SN as a tool for integrating surgical, radiologic, and pathologic information. Additionally, a system for recording and mapping biopsy samples has been devised to facilitate sharing of spatial information. MATERIALS AND METHODS: SN was utilized for biopsy mapping in 10 sinonasal/craniofacial oncologic procedures. Twenty-five raters with experience in anterior skull base oncology were interviewed to identify 15 anatomical structures in preoperative imaging, relying on topographical descriptions and surgical video clips. The difference in the localization of anatomical structures by raters was analyzed, using the SN-mapped coordinates as a reference (this difference was defined as spatial error). RESULTS: The analysis revealed an average spatial error of 9.0 mm (95 % confidence interval: 8.3-9.6 mm), with significant differences between surgeons and radiation oncologists (7.9 mm vs 12.5 mm, respectively, p < 0.0001). The proposed model for transferring SN-mapped coordinates can serve as a tool for consultation in multidisciplinary discussions and radiotherapy planning. CONCLUSIONS: The current standard method to evaluate disease extension and margin status is associated with a spatial error approaching 1 cm, which could affect treatment precision and outcomes. The study emphasizes the potential of SN in increasing spatial precision and information sharing. Further research is needed to incorporate this method into a multidisciplinary workflow and measure its impact on outcomes.

Endoscopic-assisted transorbital extended orbital exenteration: A multi-institutional preclinical study.

BACKGROUND: Sinonasal malignancies with orbital invasion have dismal prognosis even when treated with orbital exenteration (OE). Sugawara et al. developed a surgical strategy called "extended-OE (EOE)," showing encouraging outcomes. We hypothesized that a similar resection is achievable under endoscopic guidance through the exenterated orbit (endoscopic-EOE). METHODS: The study was conducted in three institutions: University of Vienna; Mayo Clinic; University of Insubria; 48 orbital dissections were performed. A questionnaire was developed to evaluate feasibility and safety of each step, scoring from 1 to 10, ("impossible" to "easy," and "high risk" to "low risk," respectively), most likely complication(s) were hypothesized. RESULTS: The step-by-step technique is thoroughly described. The questionnaire was answered by 25 anterior skull base surgeons from six countries. Mean, median, range, and interquartile range of both feasibility and safety scores are reported. CONCLUSIONS: Endoscopic-EOE is a challenging but feasible procedure. Clinical validation is required to assess real-life outcomes.

The evaluation of ozone and betahistine in the treatment of tinnitus.

The aim of the study is to evaluate the effectiveness of ozone and betahistine treatments in the treatment of tinnitus. Sixty-eight patients were enrolled in this randomized, prospective controlled study. The ozone group consisted of 27, betahistine group consisted of 26 and control group consisted of 15 patients. The patients in ozone group received 10 sessions of ozone treatment via major autohemotherapy. Betahistine group received 48 mg/day betahistine tablets per oral for 3 months duration. The control group was followed up without any treatment given. The evaluation of tinnitus was made by tinnitus loudness and tinnitus handicap inventory (THI). The changes in findings from baseline to 3rd and 6th months were assessed, and the group results were compared. Comparison of the initial mean tinnitus loudness and 3 and 6 months after treatment in each of the three groups did not reveal a significant difference. The comparison between the groups in terms of the improvement of tinnitus loudness was not significant (p = 0.821). Comparison of the initial mean THI and 3 and 6 months after treatment revealed a significant difference in ozone and betahistine groups but not in the control group. When the delta (Δ) THI (the change of mean THI between the initial and 6th month) was compared between the groups, there was no significant difference. This randomized controlled study investigating the effects of ozone in tinnitus tries to shed light to a new method of treatment in tinnitus. The findings of the study does not provide enough evidence to support ozone and betahistine as a treatment for tinnitus and further research on the subject is necessary.

Approaches to subperiosteal orbital abscesses.

The purpose of this paper is to evaluate the epidemiology, clinical features, management and complications of subperiosteal orbital abscesses (SPOA)-a serious complication of rhinosinusitis. Retrospective data of 36 patients with SPOA secondary to acute rhinosinusitis from January 1998 to December 2011 were evaluated. Patients were analyzed in terms of age, gender, clinical features, CT findings, surgical procedures, microbiology, and complications. Twenty-three males and 13 females aged from 3 to 76 were evaluated. Nine patients-seven of which were under the age of 10-with small medial SPOA were treated only with medical management. Of the 13 with medial SPOA, transnasal endoscopic approach was performed for 10 and external approach for 3 to drain the abscess. As for the 12 patients with superior SPOA, 8 were treated via combined approach and 4 via external approach. The most common microorganisms were streptococci in children and anaerobes in adults. Total loss of vision developed in two adults with diabetes mellitus (DM). One patient with superior SPOA died due to frontal lobe abscess. Young children with small medial SPOA without significant ocular signs may successfully be managed medically. Surgical drainage is indicated for nonmedial abscesses, large medial abscesses with severe visual loss and with insufficient response to medical management. The risk of blindness from SPOA is higher in patients with DM.

Can Wideband Tympanometry Predict the Prognosis of Otitis Media With Effusion?

Background and Objectives: This study aims to evaluate the capacity of wideband tympanometry (WBT) in predicting the prognosis of otitis media with effusion (OME). Subjects and Methods: Sixty-one ears with effusion and 30 healthy ears of children were enrolled. The patients were followed up monthly using WBT. After the completion of measurements, the ears were separated into four groups according to the duration of recovery; Group 1: Good prognosis (≤1-month, n=18), Group 2: Worse prognosis (>1-month, n=29), Group 3: Surgical (no recovery, n=14), and Group 4: Control (healthy ears, n=30). Tympanometric peak pressure (TPP), resonance frequency (RF), and absorbance levels were compared within and between the groups. Results: The TPP and RF values of the study group were lower than those of the controls (p<0.001). The ears with OME had lower absorbance measures than the controls at all frequencies; the differences were significant at 250, 500, and 1,000 Hz (p<0.001). However, at 2,000 Hz, the absorbance levels of the ears with OME were similar with those of the control group only in the good prognosis group (p>0.05). The receiver-operating characteristic analysis revealed that absorbance measures over 0.237 and 0.311 at 1,000 Hz and 2,000 Hz, respectively, have sensitivities and specificities over 70% for prediction of good prognosis, and the calculated odd ratio for these measures were 6 (p<0.05). Conclusions: WBT measurement is promising in predicting the recovery of OME in children.

Management of Basal Cell Carcinomas: Clinical Experience.

Objective: Basal cell carcinomas (BCC) mostly originate from the head and neck region. Main goal in BCC treatment is to achieve both aesthetic and functional results while observing the principles of tumor surgery. We report our experience regarding the clinical, histopathological features and surgical treatment results of head and neck basal cell carcinomas in the light of the literature. Methods: Files of patients with head and neck BCCs treated surgically in two university hospitals were retrospectively analyzed. Sociodemographic variables, location and size of tumor, pathological subtype, recurrence ratio, complications and technique of reconstruction were evaluated. Results: We analyzed 119 tumoral lesions in 105 patients of whom 55 (52.4%) were male and 50 (47.6%) were female. Their mean age was 67.3±12 years. The nasal region was the most common location area (n=42, 35.3%). Mean tumor size was 12.6 mm and tumor size range was 2-85 mm. The most commonly used reconstruction techniques were flap surgery, followed by primary closure, and skin grafts. Conclusion: It is important to remove the tumor with a clear surgical margin at least 4 mm and evaluate the five surgical margins with frozen sections intraoperatively. Operations are often performed under local anesthesia and are well tolerated by patients. The most common flaps used in the reconstruction are not only easy to learn but also sufficient in most cases. Skin grafts are good choices in defects located in the cavum concha and the external meatus.

Resection of the internal carotid artery in selected patients affected by cancer of the skull base.

Invasion of the internal carotid artery (ICA) has been historically considered a criterion of non-resectability of skull base cancer (SBC). Patients affected by SBC who underwent surgery including resection of ICA at two tertiary institutions were included. Demographics, oncologic, and surgical information, complications, and survival outcomes were retrospectively reviewed. Survival outcomes were calculated. Ten patients were included. Three surgical approaches (transnasal endoscopic, transorbital, and transpetrosal) were employed to resect the invaded/abutted tract(s) of the ICA. All patients underwent ICA temporary balloon occlusion test. In two patients, an extracranial-to-intracranial arterial bypass was harvested. Major neuromorbidity was observed in two patients. Perioperative mortality of the series was 10.0%. Mean overall survival was 27.2 months, with 2-year overall and progression-free survival rate of 88.9%. ICA resection is feasible as part of the ablation performed for very advanced SBCs. Survival outcomes are acceptable in adequately selected patients.

Protective effect of N-acetylcysteine from drug-induced ototoxicity in uraemic patients with CAPD peritonitis.

AIM: Peritonitis is currently one of the leading complications of continuous ambulatory peritoneal dialysis (CAPD) treatment. Aminoglycosides and vancomycin are used in the treatment of CAPD peritonitis despite their potential risk for ototoxicity. N-acetylcysteine (NAC) is a molecule used in the treatment and prophylaxis of many diseases related to oxidative stress. The aim of this study was to examine whether ototoxicity due to antibiotics used in the treatment of CAPD peritonitis can be prevented by NAC. METHODS: Sixty patients, who first developed CAPD peritonitis attacks from February 2008 to April 2010 were included in this study. Patients were divided into two groups, those taking an additional NAC treatment (n = 30) and a control group (n = 30). Low- and high-frequency hearing function tests were performed on the two groups before treatment (baseline), at the end of the first (early follow-up) and the fourth week after the treatment (late follow-up). Total doses of vancomycin and amikacin were recorded. RESULTS: There was no statistically significant difference between the groups in terms of hearing functions at the beginning. However, patients taking NAC had better hearing function test results 4 weeks after the treatment compared with those of the control group (P < 0.05). There were no statistical differences between posttreatment low-frequency hearing function tests conducted at the baseline and the first and the fourth weeks in patients taking NAC. The first and the fourth week's low-frequency hearing functions worsened when compared with the baseline low-frequency results in the control group (P < 0.001). It was found that NAC had a protective effect against ototoxicity on low-frequency (0.25-8 KHz) hearing functions. The first and the fourth week's high-frequency hearing functions improved when compared with baseline high-frequency hearing functions in patients taking NAC (P < 0.05), while they worsened. The first and fourth week's high-frequency tests worsened when compared with the baseline high-frequency tests in the control group (P < 0.001). CONCLUSIONS: The present study suggests that intraperitoneal aminoglycoside and vancomycin administration in CAPD patients may cause low- and high-frequency hearing loss, and this ototoxic effect is related to the dose given. It was found that when the antioxidant NAC is administered alone, it prevents ototoxicity, associated with intraperitoneal amikacin and vancomycin in patients with CAPD peritonitis. In addition, it was revealed that NAC may also have a curative effect on impaired high-frequency hearing functions.