[Treatment of nasolacrimal duct obstruction from the otorhinolaryngologist's perspective]. / Die Behandlung von Tränenwegsstenosen aus HNO­ärztlicher Sicht.

BACKGROUND: Epiphora is the classic symptom of nasolacrimal duct obstruction, particularly among elderly people. Dacryocystorhinostomy (DCR) via external (Toti) and endonasal (West) approaches are well-established surgical treatments. OBJECTIVE: The aim of the present article is to describe the etiology and diagnostics of nasolacrimal duct obstruction. Furthermore, treatment modalities are discussed according to the current literature, with particular consideration of the otorhinolaryngologist's perspective. MATERIALS AND METHODS: A search of the current literature focused on the past 5 years was performed in PubMed. RESULTS: Several retrospective and prospective randomized studies describe the external and endonasal DCR approaches as safe surgical procedures, with high success rates of around 90 %. The endoscope is standardly used for visualization during the endonasal approach. Powered instruments such as diamond drills enable generation of a large rhinostomy, even in very hard bone. The application of silicone stents does not confer a significant additional advantage in terms of postoperative success rates. CONCLUSION: DCR is a safe surgical procedure with high success rates. It can be strongly recommended for patients suffering from intra- or post-saccular nasolacrimal duct obstruction. Furthermore, the external and endonasal approaches (according to Toti and West, respectively) are comparable techniques. The use of silicone stents is indicated only in special cases.

Short-term severe thyroid hormone deficiency does not influence sleep parameters.

PURPOSE: The influence of short-term severe thyroid hormone deficiency on sleep is currently still unknown. Several studies have demonstrated an effect of long-term hypothyroidism on sleep disorders due to anatomical changes of the pharynx or body mass. The aim of this preliminary study, however, is to evaluate the changes in sleep patterns of patients with short-term hypothyroidism to elucidate the isolated effect of thyroid hormone withdrawal before anatomical changes can potentially occur. METHODS: Ten patients with differentiated thyroid carcinoma were enrolled in this study. Two patients discontinued the study and one patient was finally excluded due to obesity, so that the datasets of seven patients were available for study analysis. During the course of carcinoma treatment, each patient had previously undergone total thyroidectomy and I-131 remnant ablation. Polysomnographic measurements were performed twice: (1) over the course of two consecutive nights during severe thyroid hormone deficiency after levothyroxine withdrawal and prior to further diagnostics and therapy and (2) during euthyroidism after substitution with levothyroxine. RESULTS: Comparison of the Epworth Sleepiness Scale during hypo- and euthyroidism for each patient revealed no statistically significant difference. Furthermore, the comparison of polysomnographic parameters like (1) apnea-hypopnea index, (2) the duration of various sleep stages, (3) duration of rapid eye movement sleep, (4) latency until rapid eye movement sleep, (5) total sleep time, (6) periodic leg movements, and (7) arousal index showed no statistically significant differences between the hypothyroid or euthyroid state. CONCLUSIONS: We conclude that, in this preliminary experimental setting, short-term severe thyroid hormone deficiency per se does not cause sleep disturbances and a feeling of fatigue as described in other studies may be due to changes in perception or brain metabolism during hypothyroidism.

[Postoperative complications after surgery for vestibular schwannoma via the MCF approach]. / Postoperative Komplikationen nach transtemporaler Resektion von Akustikusneurinomen.

BACKGROUND: The aim of this study was to analyze complications after surgery for vestibular schwannoma (VS) via the middle cranial fossa (MCF) approach. PATIENTS AND METHODS: 112 consecutive patients have been operated on via MCF approach in our department between October 2005 and March 2011. Postoperative complications have been registered during hospital stay as well as during outpatient follow-up. RESULTS: 25 complications occurred in 20 patients, most common was a CSF leak (12%). In 9 cases leakage stopped after conservative management. 3 patients needed lumbar drainage and 1 patient had to undergo revision-surgery. 6 patients suffered from hemorrhage: 2 cerebellar bleedings, 1 subdural hematoma, 2 hematomas of the scalp and 1 bleeding of the sutured wound. All bleedings except the case with subdural hematoma could be managed conservatively. Furthermore, one case of meningitis and one transient ischemic attack were observed. 3 patients suffered from a deep venous thrombosis which led to a lethal pulmonary embolism in one case. CONCLUSIONS: Surgery for VS via the MCF approach is an established method with satisfying functional results and a low -complication rate. CSF leak is a common complication (12%) that can be managed conservatively in most of the cases. Severe complications that may lead to revision surgery are rare (2%). Persisting sequels of these complications occur in less than 1% of the cases.

[Direct recording from cochlear nerve via a ball-electrode in transtemporal acoustic neuroma surgery]. / Direkte Ableitung vom Nervus cochlearis bei transtemporaler Resektion von Vestibularisschwannomen.

BACKGROUND: Intraoperative monitoring (IOM) of the cochlear nerve function during acoustic neuroma surgery is employed to assist in preserving hearing. So far, Auditory Brain-stem Response (ABR) is considered to be an optimal method for intraoperative monitoring in transtemporal approach. The aim of this study was to perform direct recording of the cochlear nerve action potential after resection of the tumor by using a ball-electrode and to evaluate the use of this method in predicting the postoperative hearing. The obtained data were compared to the simultaneous ABR results and to the postoperative hearing. MATERIAL AND METHODS: In 2009, 38 patients have undergone acoustic Neuroma Surgery at the ENT University hospital, Wuerzburg. In 33 patients an intraoperative ABR as well as a direct measurement from the cochlear nerve using a ball electrode were performed. In 5 patients the postoperative hearing was predicted using the direct measurement at the cochlear nerve only. RESULTS: The direct recording from the cochlear nerve gave very robust responses. Even in cases where ABR recording was not possible, the identification of clear cochlear nerve action potential could still be reached. Using the direct recordings from the cochlear nerve to predict the post operative hearing turned out to have a sensitivity of 100% and a specificity of 70%. CONCLUSIONS: These results show that intraoperative monitoring with direct recording from the cochlear nerve via a ball-electrode in transtemporal approaches offers a valuable method to predict the postoperative hearing. Further investigation will be made to provide additional information.

Aspects of nitrogen dioxide toxicity in environmental urban concentrations in human nasal epithelium.

Cytotoxicity and genotoxicity of nitrogen dioxide (NO(2)) as part of urban exhaust pollution are widely discussed as potential hazards to human health. This study focuses on toxic effects of NO(2) in realistic environmental concentrations with respect to the current limit values in a human target tissue of volatile xenobiotics, the epithelium of the upper aerodigestive tract. Nasal epithelial cells of 10 patients were cultured as an air-liquid interface and exposed to 0.01 ppm NO(2), 0.1 ppm NO(2), 1 ppm NO(2), 10 ppm NO(2) and synthetic air for half an hour. After exposure, genotoxicity was evaluated by the alkaline single-cell microgel electrophoresis (Comet) assay and by induction of micronuclei in the micronucleus test. Depression of proliferation and cytotoxic effects were determined using the micronucleus assay and trypan blue exclusion assay, respectively. The experiments revealed genotoxic effects by DNA fragmentation starting at 0.01 ppm NO(2) in the Comet assay, but no micronucleus inductions, no changes in proliferation, no signs of necrosis or apoptosis in the micronucleus assay, nor did the trypan blue exclusion assay show any changes in viability. The present data reveal a possible genotoxicity of NO(2) in urban concentrations in a screening test. However, permanent DNA damage as indicated by the induction of micronuclei was not observed. Further research should elucidate the effects of prolonged exposure.

Ex vivo toxicity of nitrogen dioxide in human nasal epithelium at the WHO defined 1-h limit value.

Current pollution limits indicating potential harm to human health caused by nitrogen dioxide have prompted a variety of studies on the cytotoxicity and genotoxicity of nitrogen dioxide (NO2) in vitro. The present study focuses on toxic effects of NO2 at the WHO defined 1-h limit value of 200 µg NO2/m(3) air, equivalent to 0.1 ppm NO2. Nasal epithelial mucosa cells of 10 patients were cultured as an air-liquid interface and exposed to 0.1 ppm NO2 for 0.5 h, 1 h, 2 h and 3 h and synthetic air as negative control. After exposure, analysis of genotoxicity was performed by the alkaline single cell microgel electrophoresis (comet) assay and by the micronucleus test. Depression of proliferation and cytotoxic effects were checked by the micronucleus assay and the trypan blue exclusion assay. The experiments demonstrated significant DNA fragmentation even at the shortest exposure duration of half an hour in the comet assay. The amount of DNA fragmentation significantly increased with extended NO2 exposure durations. The amount of DNA fragmentation increased with extended exposure durations to synthetic air at a significantly lower level as compared to NO2 exposure. Micronucleus inductions were seen only at the longest exposure duration of 3h. There were no changes in proliferation seen in the micronucleus assay under any experimental setup. Moreover, no signs of necrosis, apoptosis or changes in viability were detected. Data demonstrate genotoxicity of NO2 at concentrations found in the urban atmosphere during short exposure durations. DNA alterations in the micronucleus assay at an exposure time of 3h indicate a significant DNA alteration possibly being hazardous to humans.