Intraluminal three-dimensional optical coherence tomography - a tool for imaging of the Eustachian tube?

OBJECTIVES: The cause of Eustachian tube dysfunction often remains unclear. Therefore, this study aimed to examine the feasibility and possible diagnostic use of optical coherence tomography in the Eustachian tube ex vivo. METHODS: Two female blackface sheep cadaver heads were examined bilaterally. Three conditions of the Eustachian tube were investigated: closed (resting position), actively opened and stented. The findings were compared (and correlated) with segmented histological cross-sections. RESULTS: Intraluminal placement of the Eustachian tube with the optical coherence tomography catheter was performed without difficulty. Regarding the limited infiltration depth of optical coherence tomography, tissues can be differentiated. The localisation of the stent was accurate as was the lumen. CONCLUSION: The application of optical coherence tomography in the Eustachian tube under these experimental conditions is considered to be a feasible, rapid and non-invasive diagnostic method, with possible diagnostic value for determining the luminal shape and superficial lining tissue of the Eustachian tube.

[Determination of normal values of extraesophageal reflux in 24-h two-channel pH testing]. / Normalwertbestimmung des extraösophagealen Reflux (EER) in der 24-h-2-Kanal-pH-Metrie.

Extraesophageal reflux (EER) causes multiple diseases of the upper aerodigestive tract. EER is diagnosed by two-channel pH testing. However, little data exist about normal values. Therefore, we performed ambulatory two-channel pH testing in healthy volunteers and determined normal values for the number of reflux episodes, fraction, and reflux area index. These values were determined for pH 14.72 were excluded from the evaluation. In the other patients, the mean number of reflux episodes was 2.6+/-0.9 (95(th) percentile 4.4), the fraction of pH

[Ultrasound of hypopharyngeal and oesophageal cancer: possibilities and limitations to staging and planning of therapy]. / Die sonographische Beurteilbarkeit des Hypopharynx und des extrathorakalen Osophagus: Möglichkeiten und Grenzen für Staging und Therapieplanung.

Sonographic examination of the hypopharynx and the extrathoracic oesophagus can be difficult. Therefore, most surgeons prefer to utilise CT or MRI scanning. Surgery is planned on the basis of endoscopic findings combined with radiologic information. The aim of the present prospective study was to demonstrate that the combination of ultrasonography and endoscopy provides a sufficient basis for the planning of surgical interventions in patients suffering from hypopharyngeal cancer or cancer of the proximal oesophagus. In 10 patients with squamous cell carcinoma of the hypopharynx/proximal oesophagus (8T4, 2T2) and 2 patients with a T4 squamous cell carcinoma of the larynx, both preoperative CT and ultrasound were performed and compared with the extent of the tumour seen during endoscopy. With ultrasound, the T4 tumours of the hypopharynx were recognized well as opposed to the T2 tumours which were not detected. The CT results were similar. An infiltration of the proximal oesophagus was seen with both imaging techniques in all affected patients. In contrast to CT, intralaryngeal tumour spread was not seen with ultrasound as long as the laryngeal skeleton was intact. The retropharyngeal region could also not be examined by ultrasound. Nevertheless, these results show that in all patients included in this study the extent of the tumour could have been estimated correctly by using ultrasound plus endoscopic examination alone. The reliable examination of this anatomically difficult region, however, requires examiner experience.

Increased PGE2 levels in nonmalignant mucosa adjacent to squamous cell carcinoma of the head and neck.

OBJECTIVE: The cyclooxygenases (COX) 1 and 2 are the rate-limiting enzymes of prostaglandin E(2) (PGE(2)) synthesis, and the upregulation of COX-2 has been reported in tumors of different origins. The aim of our study was to quantify the PGE(2) expression in squamous cell carcinoma and surrounding mucosa, to analyze the potential of acetylsalicylic acid (ASA) for reducing PGE(2) levels in these tissues, and to improve our understanding of potential tumor-derived stimulation of surrounding mucosa by PGE(2). STUDY DESIGN AND SETTING: Intracellular PGE(2) levels in primary head and neck squamous cell carcinoma (HNSCC) and the surrounding mucosa at 1 and 2 cm distance were analyzed ex vivo by ELISA. Subsequently, we treated in vitro tumor and normal mucosal cells from turbinates with recombinant PGE(2) and ASA, and quantified intracellular PGE(2) levels. RESULTS: We observed high PGE(2) levels in the tumor samples and in tumor-surrounding mucosa. The addition of PGE(2) and arachidonic acid to tumor cell cultures resulted in no further increase in intracellular PGE(2) levels, while ASA reduced PGE(2) levels by up to 40%. In normal epithelial cell cultures, less PGE(2) (6% of that found in the tumor cells) was expressed, but stimulation with PGE(2) resulted in levels comparable to those of the tumor samples. CONCLUSION AND SIGNIFICANCE: We conclude that HNSCC and the surrounding mucosa express high levels of PGE(2). This expression is reduced efficiently by ASA. We propose a stimulation of PGE(2) expression in the epithelium surrounding HNSCC by tumor-derived PGE(2) with a potential impact on tumor growth.

[The need for 24-h double probe pH monitoring in the diagnosis of laryngo-pharyngeal reflux]. / Zur Notwendigkeit der zweikanaligen 24-h-pH-Metrie in der Diagnostik des laryngopharyngealen Reflux.

BACKGROUND: Laryngopharyngeal reflux disease (LPRD) can have various causes. Because LPRD differs from gastroesophageal reflux disease (GERD), the pH monitoring has to be performed directly next to the entrance of the larynx. This is now possible using a new system called pH-RESPONSE. METHODS: The ambulatory pH was monitored using the double probe pH-RESPONSE in 20 patients with suspected LPRD. The number of refluxes, the number of long refluxes and the period in which the pH was below 4 were compared at the level of the larynx with the data from the esophageal electrode. The DeMeester score was also determined. RESULTS: The system was well tolerated by 19/20 patients. In 12 patients a GERD could be proved and ten also had LPRD. Surprisingly, these patients had no typical signs such as heart burn. The number of refluxes measured in the esophagus was a third that of the larynx. The average time of pH below 4 was 30 min. CONCLUSION: The pH-RESPONSE easily allows ambulatory 24 -h double probe pH monitoring to diagnose LPRD. Because large differences were found between data form the esophagus from the level of the larynx, 24-h double probe pH monitoring should be a standard procedure before starting any therapy for LPRD.

[Interdisciplinary therapy management in malignancy of the paranasal sinus tumors in children]. / Interdisziplinäres Therapiemanagement maligner Nasennebenhöhlentumoren im Kindesalter.

BACKGROUND: Malignant tumors of the paranasal sinuses, such as rhabdomyosarcoma or Ewing's tumors, often have a mesenchymal origin. In the recent years, several prospective, randomized, multicenter studies have demonstrated a better outcome after new oncology therapy protocols. PATIENTS AND RESULTS: In the period from January 2000 to June 2001, we operated 610 patients with sinus disease. Only 23/610 were children or teenagers (3.8%). Half of the juvenile group suffered from chronic sinusitis, but 5/23 (22%) had a malignoma of the paranasal sinuses. In the adult population, malignoma was diagnosed in less than 1% of cases. We diagnosed and treated, in cooperation with our radiology, pathology and children's hematooncology department, one rhabdomyosarcoma, two malignant peripheral neuroectodermal tumors (PNET), one myelosarcoma and one malignant lymphoma in the paranasal sinuses. Two patients died. SUMMARY AND CONCLUSION: These five cases of paranasal sinus malignomas are discussed in relation to their history and clinical course. We suggest that interdisciplinary treatment involving otorhinolaryngology, pathology, children's hematooncology, radiology and radiation therapy is obligatory for the therapy and for the best possible outcome of such cases.

[Experimental study on the biomechanical stability of different internal fixators for use in the mandible]. / Experimentelle Untersuchung zur biomechanischen Stabliltät unterscheiedlicher Unterkieferosteosynthesen

BACKGROUND: Comparative studies of different forms of osteosynthesis require that biomechanical and biological criteria be observed. The conditions in experimental studies should be as close as possible to the in vivo situation. The aim of our study was to develop a fracture model that would allow determination of the micromovements in the gap tissue following different forms of internal fixation in fractured human mandibles. METHODS: Micromovements in the gap tissue of five human mandibles treated with different osteosynthetic systems (DCP, EDCP, Miniplates, 3-D systems) following osteotomy or fracture in the region of the corpus and median region were investigated by means of strain gauges. By fitting the human mandibles in plaster according to a method of our own it was possible to create fractures at predictable and comparable localizations. RESULTS: Our investigations show that the micromovements in the gap tissue of osteotomied and fractured mandibles are different and not dependent on the form of osteosynthesis applied. Physiological micromovements in the gap tissue were found under strain for all osteosynthetic systems used in fractured and congruently reset mandibles. DISCUSSION: Our fracture and osteosynthesis model allows the quantitative determination of micromovements in the gap tissue and shows the importance of ideal realignment, which has a decisive influence on micromovements in the gap tissue.

[Experimental and finite-element models for the assessment of mandibular deformation under mechanical loading]. / Experimentelle und Finite-Elemente-Analyse der Biomechanik des Unterkiefers unter Belastung.

Biomechanical investigations of the mandible are difficult to perform due to a variety of conditions involved. For the appropriate reconstruction of biomechanical properties, a geometrically correct body model has to be established which fits to complex in vivo conditions. The aim of our study was to evaluate the use of finite-element models (FEM) for the assessment of mandibular deformation under mechanical loading. Explanted human mandibles (n = 5) were investigated by strain gauges to determine the individual strain distribution under mechanical loading. FEM analysis based on a computed tomograph (CT) was performed and the results were matched with the test data. Our study demonstrates only minor interindividual differences in the strain distribution for each load studied. The mechanical response in terms of deformation was found to depend mainly on gross geometrical properties and to a minor extent on the various other variables. At all positions the maximum principal strain was tensile, the minimum principal strain was compressive, and the absolute strain values were correlated with the magnitude of the applied force. CT-based FEM analysis revealed the utility of mathematical models to approximate simulated data our experimental results. Hence, FEM analysis is a non-invasive tool in the prediction of biomechanical behaviour of individual mandibles and therefore may help in trauma reconstruction and treatment planning.