Erkan Tarhan

Comparison of AlloDerm, fat, fascia, cartilage, and dermal grafts in rabbits.

OBJECTIVE To compare various graft materials in the rabbit model, including autologous cartilage, dermal tissue, fat, and AlloDerm (a cadaver-derived material). METHODS Twenty-five New Zealand white rabbits were used. Equally sized autogenous (fat, fascia, cartilage, and dermal) grafts and AlloDerm were implanted into subcutaneous dorsal pockets on the rabbits. Animals were killed 1, 2, 3, and 4 months after surgery. The grafts were examined microscopically for thickness, resorption, fibrosis, neovascularization, inflammation, eosinophilia, and the presence of multinucleated giant cells or microcysts. RESULTS The cartilage grafts revealed excellent viability with no resorption. The fascial grafts showed negligible volume loss. The dermal grafts developed epidermoid cysts. The AlloDerm grafts demonstrated graft thickening at 1 month and total resorption at 3 and 4 months. The fat grafts demonstrated 30% to 60% partial resorption. CONCLUSIONS The major disadvantage of using an autogenous fat graft was partial resorption, whereas cyst formation was observed with dermal grafts. AlloDerm caused tissue reaction and resorption. The best graft material was cartilage, with a low absorption rate, good biocompatibility, and minimal tissue reaction or fibrosis, followed by fascia, with a minimal shrinkage capacity and tissue reaction.

Acoustic rhinometry: accuracy and ability to detect changes in passage area at different locations in the nasal cavity.

Objectives: To evaluate the accuracy of acoustic rhinometry (AR) measurements, and to assess how well AR detects obstructions of various sizes at specific sites in the nasal cavity, we created a cast model from an adult cadaver nasal cavity. Methods: The actual cross-sectional areas of the cast model nasal passage were determined by computed tomography and compared with the corresponding areas measured by AR. To assess how nasal obstruction affects the AR results, we placed small wax spheres of different diameters at specific sites in the model (nasal valve, head of the inferior turbinate, head of the middle turbinate, middle of the middle turbinate, choana, and nasopharynx). Results: The AR-derived cross-sectional areas in the first 6.5 cm of the cast model nasal cavity were very close to the corresponding areas calculated from computed tomographic sections perpendicular to the presumed acoustic axis. However, AR overestimated the passage areas at locations posterior to the 6.5-cm point. Acoustic rhinometry gave an accurate indication of the passage area of the nasal valve and its distance from the nostril. The nasal valve and the choana were indicated by significant dips on the AR area-distance curve, whereas the curve was smooth throughout the region that included the head of the inferior turbinate, the head of the middle turbinate, the middle of the middle turbinate, and the nasopharynx. In other words, AR did not discretely identify these latter sites. Acoustic rhinometry detected the different-sized inserts (obstructions) more accurately at the nasal valve than at sites posterior to this location. Conclusions: The results of the study show that AR is a valuable method for assessing the anterior nasal cavity. This technique is sensitive for detecting changes in passage area at the nasal valve region; however, the sensitivity is lower at sites posterior to this. The findings suggest that when there is substantial narrowing of the nasal valve, AR will not identify an obstruction at any location posterior to the nasal valve. In such situations, AR measurements beyond the abnormal nasal valve may easily lead to misinterpretation of the patients nasal anatomy or condition.

Reliability of the vestibular evoked myogenic potential test in assessing intratympanic gentamicin therapy in Meniere's disease

Conclusions. The results of this preliminary study demonstrate that with regard to determining the efficacy of intratympanic (IT) gentamicin treatment in patients with Menieres disease, the reliability of testing for vestibular evoked myogenic potentials (VEMPs) is comparable to that of caloric tests. Compared with caloric tests, VEMP measurements are more comfortable and take less time. The results of VEMP and caloric testing do not correlate with the results of hearing tests. Objective. To test the reliability of VEMP testing to monitor the results of IT gentamicin therapy in patients with Menieres disease. Subjects and methods. Twelve patients with unilateral Menieres disease were evaluated with pure tone audiometry (PTA), bithermal caloric tests, and VEMP tests. Patients with measurable caloric and VEMP results before IT gentamicin treatment were included in the study. IT gentamicin (0.5 ml) at a concentration of 40 mg/ml was administered to the patients. Reinjection was performed 10 days later depending on patients’ complaints. Patients were re-evaluated with short- and long-term VEMP, hearing, and caloric test results. Results. Caloric responses and VEMPs changed following gentamicin therapy in 9 patients and 12 patients, respectively. Long-term results of caloric and VEMP tests in patients receiving IT gentamicin treatment changed in 7 patients and 10 patients, respectively.

Vestibular functions in motion sickness susceptible individuals

There exists no functional guide that can serve as a diagnostic tool for individual susceptibility to motion sickness (MS). We evaluated vestibular system functioning via a caloric test (which assesses functioning of the superior vestibular nerve) and the vestibular-evoked myogenic potentials (VEMP) test (which assesses inferior vestibular nerve functioning) in 20 MS susceptible and 20 nonsusceptible individuals. Susceptibility to MS was determined by self-declaration and with MS susceptibility questionnaire and Hamilton Anxiety Scale (HAS). We found statistically significant differences for scores on the MS susceptibility questionnaire and HAS questionnaire; however, we found no correlation between VEMP and caloric test results. We suggest that VEMP and caloric test results are not affected by individuals’ susceptibility to MS. We could not find vestibular system deficits using the VEMP and caloric test combination. Our findings do not support vestibular function asymmetry in MS patients.

Eosinophilic ulcer of the tongue

A 76‐year‐old woman presented with a 1‐month history of a rapidly expanding painful ulcerated nodule on her tongue following tooth extraction. Triamcinolone acetonide ointment was applied twice daily for 1 month without any benefit. The histopathology of the excision specimen was consistent with an eosinophilic ulcer of the oral mucosa. There has been no recurrence 12 months later.

Esophageal Mucosal Sensitivity: Possible Links with Clinical Presentations in Patients with Erosive Esophagitis and Laryngopharyngeal Reflux

The goal of this study was to assess whether mucosal sensitivity is related to different combinations of symptoms and lesions in laryngopharyngeal reflux (LPR) and erosive esophagitis and to determine whether reflux pattern is important in the development of the symptoms and lesions of gastroesophageal reflux disease (GERD) or LPR. We conducted a prospective study of 55 unselected new patients: 27 erosive esophagitis patients and 28 LPR patients. The erosive esophagitis group had a significantly higher rate of Bernstein test positivity than the LPR group. The proportions of patients with pathologic acid reflux at the proximal and distal probe were similar in the erosive esophagitis group and in the LPR group. These results were inconsistent with the endoscopic findings. Both retrosternal heartburn and regurgitation symptoms were higher in erosive esophagitis patients. The paucity of classical GERD symptoms and lesions in LPR patients could be attributable to mucosal insensitivity but not to reflux pattern.