[Intubating laryngeal tube suction disposable: Initial clinical experiences with a novel device for endotracheal intubation]. / Intubationslarynxtubus Suction Disposable: Erste klinische Erfahrungen mit einem neuen Hilfsmittel zur endotrachealen Intubation.

BACKGROUND: According to the recent guidelines supraglottic airways, such as laryngeal tubes are recommended to ensure oxygenation in patients with unexpected difficult airways. The novel Intubating Laryngeal Tube Suction Disposable (iLTS-D) is a modified laryngeal tube designed for secondary tracheal intubation. This pilot study evaluated the use of the iLTS-D in clinical practice with respect to practicality and efficacy. METHODS: In this study the airways of 30 consecutive adult patients with no evidence of a difficult airway undergoing elective ear, nose and throat (ENT) surgery were managed with the iLTS-D. After induction of anesthesia the iLTS-D was placed in position and checked for correct ventilation. Following muscle relaxation, endotracheal intubation through the iLTS-D was performed under continuous visualization using a flexible bronchoscope. Finally, the iLTS-D was removed leaving the endotracheal tube in place. Data were collected anonymously as part of a quality assurance program. Publication of the data was approved by the institutional review board. RESULTS: Initial iLTS-D placement took a median of 17 s (range 12-90 s) and provided sufficient ventilation in all patients; however, the position of the iLTS-D needed to be adjusted in four patients. Endotracheal intubation through the iLTS-D was achieved in 29 out of 30 patients at the first attempt (n = 23) or after 2 attempts (n = 6) and the median time required for intubation was 32 s (range 18-187 s). In five patients no laryngeal structures could initially be identified by bronchoscopy. Blind endotracheal intubation through the iLTS-D was performed in two cases and in two other patients the endotracheal tube was also blindly advanced but into the esophagus. After removal of the endotracheal tube and repositioning of the iLTS-D, successful tracheal intubation was subsequently achieved under bronchoscopic vision. The procedure was aborted and uneventful conventional intubation using direct laryngoscopy was carried out in one patient. The median time for removal of the iLTS-D after successful intubation was 20 s (range 15-80 s). Minor blood stains on the iLTS-D were observed in three patients. With one exception, all problems and adverse events occurred during the first 10 patients. CONCLUSION: This first clinical study demonstrated that in patients with apparently normal airways and in the hands of users without previous experience, the iLTS-D allowed sufficient ventilation in all patients and had a high success rate for subsequent endotracheal intubation. The results are, however, preliminary until confirmed by further studies, particularly in patients with difficult airways.

[Histology after tonsillectomy?]. / Histologie nach Tonsillektomie?

BACKGROUND: The necessity to rule out clinically occult malignancies by routine histological examination of all tonsillectomy specimens is a controversial topic. METHODS: Clinical and histological findings of all patients who underwent tonsillectomy at the University of Bonn, Germany from January 2002 to March 2007 were retrospectively reviewed. A meta-analysis of PubMed literature regarding the histological results of tonsil specimens was performed. The incidence of clinically occult tonsil malignancy was recorded and potential risk factors for malignancy were analyzed. A cost-effectiveness ratio of microscopic analysis of all specimens was also performed. RESULTS: Clinically occult tonsil malignancies were detected in 2 out of the 1,523 patients (0.13%) in this study. In the meta-analysis of 24 studies (61,550 patients) 6 cases of clinically occult tonsil malignancies (0.01%) were identified. Statistically 7,694 tonsils have to be histologically examined to detect 1 case of occult malignancy which corresponds to an average cost per case of 385,000 EUR. DISCUSSION: Considering economical aspects we recommend that histological examination should be performed when the following risk factors are present: a history of cancer, tonsil firmness or lesions, tonsillar asymmetry, swelling of neck lymph nodes, constitutional symptoms, anamnestic unilateral symptoms and prior peritonsillar abscess.

[Tissue engineering of respiratory epithelium. Regenerative medicine for reconstructive surgery of the upper airways]. / Tissue-Engineering von respiratorischem Epithel. Regenerative Medizin für die rekonstruktive Chirurgie der oberen Atemwege.

Reconstruction of long tracheal defects remains an unsolved surgical problem. Tissue engineering of respiratory epithelium is therefore of utmost surgical and scientific interest. Successful cultivation and reproduction of respiratory epithelium in vitro is crucial to seed scaffolds of various biomaterials with functionally active respiratory mucosa. Most frequently, the suspension culture as well as the tissue or explant cultures are used. Collagenous matrices, synthetic and biodegradable polymers, serve as carriers in studies. It is essential for clinical practice that mechanically stable biomaterials be developed that are resorbable in the long term or that cartilaginous constructs produced in vitro be employed which are seeded with respiratory epithelium before implantation. Vascularization of a bioartificial matrix for tracheal substitution is also prerequisite for integration of the constructs produced in vitro into the recipient organism. Here, the state of the art of research, perspectives and limitations of tracheal tissue engineering are reviewed.

[Cell-based strategies for salivary gland regeneration]. / Zellbasierte Strategien für die Speicheldrüsenregeneration.

Xerostomia as a side effect of radiotherapy or due to Sjögren's disease leads to considerable impairment of the quality of life of the affected patients. Preventive treatment approaches such as intensity-modulated radiotherapy, surgical transfer of a submandibular gland to a site outside the radiation field or administration of amifostin during radiation treatment are not yet completely established in clinical practice and are not applicable for all patients. Symptomatic treatment with pilocarpin or synthetic saliva leads to an improvement of the symptoms only in some patients, and in the case of pilocarpin significant systemic anticholinergic side-effects might occur. Because large numbers of patients are affected and current treatment options are not satisfactory, it is essential to develop new treatment options. In parallel with the in vitro production of functional salivary gland constructs by means of tissue engineering techniques, attempts are currently under way to experimentally restore salivary gland function by genetic treatment approaches such as transfection of the affected salivary glands with aquaporins or pro-angiogenic factors. In addition, the in vivo application of stem cells is under investigation. In the present paper, we discuss the clinical and radiobiological background of xerostomia and highlight possible innovative future treatment options.

[Rare sialadenoma papilliferum in the hard palate: case report and survey of the literature]. / Das seltene Sialadenoma papilliferum am harten Gaumen : Fallbericht und Literaturübersicht.

Sialadenoma papilliferum is a rare tumour of the salivary glands that usually occurs in the oral cavity. Following the course of the salivary glands of the oral mucosa, the hard and soft palate are the most common locations of this tumor. In the international literature, only a few case reports about this entity can be found. We present a 63-year-old patient with a sialadenoma papilliferum accidentally found during diagnostic procedures for progredient dysphagia. Suffering from infrabifurcal cancer of the oesophagus, the patient had undergone partial oesophagectomy 1 year before. Histological verification was performed with a tumor biopsy at the border of hard and soft palate, on the right side. This case is compared with 39 further cases reported in the literature. The therapy of choice is resection of the tumor. Because of the high frequency of recurrence, in sano resection should be planned.

Eosinophilia in nasal polyposis: its objective quantification and clinical relevance.

BACKGROUND: Eosinophilia within nasal polyps is often taken as a criterion for adjuvant medical treatment postoperatively such as topical steroids. OBJECTIVE: This study was performed in order to validate a new technique for objective quantification of eosinophilia by using laser scanning cytometry (LSC), to compare these results with manual scoring and routine histopathology, and to correlate them with the history of allergy or recurrence. METHODS: LSC was used for semi-automated analysis of single-cell preparations from representative ethmoidal polyps obtained during routine paranasal sinus surgery (n=41). This microscope-based instrument scans the cells after immobilization of cells on a glass slide and after triple staining of cytokeratin, eosinophilic granula, and DNA. The location of each cell is stored with the fluorescence data. Therefore, the morphology of every cell can be documented by re-staining with haemotoxylin and eosin and re-localization on the slide. Subsequently, slides were subjected to manual scoring. The remaining polyps were analysed by routine histopathology. RESULTS: Data from LSC and manual scoring showed good correlation (r=0.81, P<0.001), whereas there were discrepancies with histopathology. Eosinophilia scored by LSC and histopathology was neither correlated with the history of allergy nor with recurrence as determined by Fisher's exact test independent of the definition of eosinophilia (> or =2%, > or =3%, or > or =5% of all cells). CONCLUSION: Scoring eosinophilia by LSC in comparison with histopathology does not contribute to a more reliable basis for adjuvant medical therapy in nasal polyposis. Instead, functional parameters (cytokine production, apoptosis) may serve better.

Tissue engineering in otorhinolaryngology.

Tissue engineering is a field of research with interdisciplinary cooperation between clinicians, cell biologists, and materials research scientists. Many medical specialties apply tissue engineering techniques for the development of artificial replacement tissue. Stages of development extend from basic research and preclinical studies to clinical application. Despite numerous established tissue replacement methods in otorhinolaryngology, head and neck surgery, tissue engineering techniques opens up new ways for cell and tissue repair in this medical field. Autologous cartilage still remains the gold standard in plastic reconstructive surgery of the nose and external ear. The limited amount of patient cartilage obtainable for reconstructive head and neck surgery have rendered cartilage one of the most important targets for tissue engineering in head and neck surgery. Although successful in vitro generation of bioartificial cartilage is possible today, these transplants are affected by resorption after implantation into the patient. Replacement of bone in the facial or cranial region may be necessary after tumor resections, traumas, inflammations or in cases of malformations. Tissue engineering of bone could combine the advantages of autologous bone grafts with a minimal requirement for second interventions. Three different approaches are currently available for treating bone defects with the aid of tissue engineering: (1) matrix-based therapy, (2) factor-based therapy, and (3) cell-based therapy. All three treatment strategies can be used either alone or in combination for reconstruction or regeneration of bone. The use of respiratory epithelium generated in vitro is mainly indicated in reconstructive surgery of the trachea and larynx. Bioartificial respiratory epithelium could be used for functionalizing tracheal prostheses as well as direct epithelial coverage for scar prophylaxis after laser surgery of shorter stenoses. Before clinical application animal experiments have to prove feasability and safety of the different experimental protocols. All diseases accompanied by permanently reduced salivation are possible treatment targets for tissue engineering. Radiogenic xerostomia after radiotherapy of malignant head and neck tumors is of particular importance here due to the high number of affected patients. The number of new diseases is estimated to be over 500,000 cases worldwide. Causal treatment options for radiation-induced salivary gland damage are not yet available; thus, various study groups are currently investigating whether cell therapy concepts can be developed with tissue engineering methods. Tissue engineering opens up new ways to generate vital and functional transplants. Various basic problems have still to be solved before clinically applying in vitro fabricated tissue. Only a fraction of all somatic organ-specific cell types can be grown in sufficient amounts in vitro. The inadequate in vitro oxygen and nutrition supply is another limiting factor for the fabrication of complex tissues or organ systems. Tissue survival is doubtful after implantation, if its supply is not ensured by a capillary network.

[Multimodal treatment strategy for Langerhans cell histiocytosis at head and neck manifestations]. / Interdisziplinäre Therapie der Langerhans-Zell-Histiozytose im Kopf- und Halsbereich.

Langerhans cell histiocytosis (LCH) is a rare disorder with different clinical features. An established standardized treatment does not exist.We present a case report of a patient with localized LCH of the temporal bone and discuss the interdisciplinary treatment strategies. We reviewed the international literature and summarized the current knowledge. Beside a wait and see policy in cases without symptomatic disease, surgery, radiotherapy or chemotherapy, and combinations of these options are used as treatment modalities. While surgery or radiotherapy are preferred in localized (symptomatic) lesions, stage-adapted chemotherapeutic regimens are the treatments of choice in disseminated disease. Treatment selection depends on the individual clinical features.

Tissue engineering of human salivary gland organoids.

Radiation therapy for malignant head and neck tumours is mainly responsible for inadvertent damage of the salivary glands. Xerostomia is the major symptom of this condition, with consequent mucositis, dental caries, dysphagia and nutritional deficits. At present there is no routine treatment for radiation-induced salivary dysfunction. Based on the principles of tissue engineering, this study presents a new experimental concept for reconstituting salivary gland function after radiation therapy for head and neck cancer. Human parotid cells were cultured with two different types of commercially available microcarriers-Cytodex 3 and Cytopore 1-for up to 3 weeks in vitro. Cultures were controlled daily by means of inverted microscopy. Medium samples were tested for alpha-amylase, tissue polypeptide antigen (TPA) and S100 in order to control parotid cell function in vitro. The vitality of the cells was investigated by in vitro staining with erythrosine. Immunocytochemical analysis for amylase and cytokeratin was performed in order to confirm epithelial character and maintain acinar cell type. Parotid gland cells could be cultured in a differentiated and vital state on both types of microcarriers for up to 3 weeks. Almost all of the cultured cells exhibited immunoreactivity for cytokeratin. High concentrations of TPA, a specific marker for salivary duct epithelium, indicated persistent differentiation of this cell type in vitro. Positivity for amylase was detectable in 20-45%, of cells growing on the microcarriers, and especially on Cytodex 3. Decreasing amylase levels in the culture medium indicated functional deficiencies of the remaining acinar cells. Tissue engineering of human salivary gland organoids on microcarriers is a new approach for potential causative treatment of radiation-induced xerostomia. Before clinical application can be considered significant improvements in the in vitro cultivation of salivary gland tissue and scaffold design have to be realized.

[Reconstruction of the frontal bone with individual titanium implants after surgical therapy of osteomyelitis of the frontal bone]. / Rekonstruktion des Os frontale mit individuellen Titanimplantaten nach chirurgischer Therapie der Stirnbeinosteomyelitis.

Individually prefabricated titanium implants enable the reconstruction of the frontal bone after surgical therapy of osteomyelitis without compromising mechanical stability or aesthetic results. Primarily the infected bone tissue is removed. Helical computed tomographic systems are used for the aquisition of patient data. After being transmitted to a computer aided design system (CAD-system) this data is used for construction of the implant geometry using freeform-surfaces. The outer surface contour is derived from the contours of the bone defect. The completed computer-based implant design is finally transformed into control data to run the milling machine which produces the implant from a block of titanium. Modern industrial CAD/CAM-technology allows standardized prefabrication using data from CT-scans. The precision of all implants was predictable and duration of the reconstructive procedure could be reduced. During postoperative follow-up (5-24 months) no loss of implant or recurrence of the osteomyelitis could be observed.

Adenosine triphosphatase expression correlates with ciliary activity of respiratory epithelium in vitro.

In vitro culture of respiratory epithelium is of great utility for pharmacological investigations and tissue engineering. Up to now, the degree of differentiation of respiratory cells cultured in vitro has exclusively been estimated by measuring ciliary beat frequency (CBF). Ciliary motility is dependent on the function of the motor protein dynein that is composed of at least two heavy chains, sharing attributes of adenosine triphosphatases (ATPases). CBF is further dependent on medium conditions and does not allow to draw any accurate conclusion on the proportion of fully differentiated ciliated cells in culture. For this reason we introduced the immunohistochemical detection of a 100-kD ATPase subunit as a correlation with dynein activity in human respiratory cell tissue culture. Our results show that the amount of immunohistochemically detectable ATPase-subunit-positive cells strongly correlates with ciliary motility in vitro. Cultures without ciliary activity exhibited no ATPase staining, whereas in cell cultures with excessive ciliary beat, up to 15.1% of the cells were ATPase positive. Immunohistochemical detection of ATPase in respiratory cell cultures seems to be a sensitive and reproducible complement for the characterization of cultured ciliated epithelium.

[Growth of human respiratory epithelium on collagen foil]. / Wachstum humanen respiratorischen Epithels auf Kollagenfolie.

BACKGROUND: Clinical application of bioartificial tracheal prosthesis must still be regarded as an experimental concept because restoration of a functional respiratory epithelium outlining the prosthesis is still not possible. Tissue engineering as a relatively new biotechnological discipline may offer new methods in expanding differentiated respiratory epithelium in vitro. In this study we compare two different cell and tissue culture procedures for growing human nasal mucosa on commercially available collagen foil. MATERIAL AND METHODS: Harvested specimens of human nasal mucosa (n = 6, 4 x 4 cm) were placed on collagen foil and incubated as tissue cultures for 4, 6 and 8 weeks. A suspension of enzymatically dispersed nasal epithelium seeded on collagen foil (5 x 10(5) cells) served as control. Cell growth and ciliary beat were monitored through an inverted microscope with Hoffman's modulation contrast and video set-up. Histological examination was performed after 4, 6 and 8 weeks. RESULTS: In the tissue cultures, the collagen foil was initially covered with fibroblasts growing from the mucosa specimen before epithelial cells spread out. The epithelial layer showed mostly ciliated cells which developed metachronous ciliary beat after 4 weeks in vitro. Ciliary activity was observed until the end of the experiments in 8 weeks. New cells on the suspension cultures were mesenchymal and did not exhibit any ciliary activity. CONCLUSIONS: Mucosa specimens seem to be more appropriate for tissue engineering of respiratory epithelium than cell suspensions from nasal epithelium. Collagen foil as tissue scaffold initiates epithelial-mesenchymal interaction and may play an important role in epithelial differentiation of new respiratory epithelium.

[DIN-oriented tensile strength evaluation of surgical tissue sutures]. / DIN-orientierte Festigkeitsprüfung chirurgischer Gewebeverbindungen.

Methods to determine the mechanical properties of surgical wounds and sutures are valuable tools in wound healing research. So far standardized testing procedures have not been defined in the surgical literature, which reduces the comparability of results from different authors. Therefore we suggest a modified tensile testing procedure which follows German industrial standards (DIN 53455). The experimental set-up includes an universal testing machine and special clamps. The dumbbell-shaped specimen consist of freshly prepared pig skin and the suture which is to be tested. Well-known mechanical properties of surgical sutures and wounds were used to approve the precision of the experimental set-up. Reproducible analysis of all tested sutures and wounds (n = 120) was possible. We recommend testing procedures adapted to industrial standards to obtain comparable results in determination of mechanical properties of surgical wounds and sutures.

[Bilateral vestibular loss as a post-infection complication of yersiniosis?]. / Bilateraler Vestibularisausfall als postinfektiöse Komplikation einer Yersiniose?

BACKGROUND: Yersinia infections other than plaque are caused by Yersinia pseudotuberculosis and Yersinia enterocolitica. Food and water contamination as well as animal-to-person and person-to-person contact are common pathways of transmission. Clinical manifestations include enteritis, enterocolitis, acute appendicitis, inflammation of the terminal ileum, and mesenteric adenitis. Y. enterocolitica may cause bacteremia with subsequent septicemia predominantly in patients with underlying illnesses such as diabetes mellitus or malignancy. More frequently enteritis is followed by immunological post-infectious syndromes such as arthritis and erythema nodosum. The present case report discusses bilateral vestibular loss possibly caused by an infection with Y. enterocolitica. PATIENTS: A 27-year-old caucasian woman initially presented with the otologic symptom of spinning vertigo accompanied by nausea and vomiting. RESULTS: Physical exam revealed spontaneous nystagmus to the left. Bithermal caloric responses were absent. Pure tone audiometry showed a bilateral symmetric high-frequency sensorineural hearing loss. Neurologic exams did not reveal involvement of the central vestibular system. Perilymphatic fistula on the left side was excluded by tympanoscopy. Serology for rheumatoid factors and HLA B27 was negative. Lead or mercury intoxication was also excluded. In her medical history the patient reported intermittent watery diarrhea and stress dependent arthralgia that had commenced during a stay in Argentina three years ago. Serology was positive, revealing elevated titers for Y. enterocolitica type 3 (1:200) and type 9 (1:400). DISCUSSION: Bilateral vestibular loss is rare. The main cause is aminoglycoside ototoxicity or meningitis. Yersina infections have not yet been described as inducing disease of the labyrinth. Present pathophysiologic knowledge of yersinia infections is described as follows: After peroral infection, gastrointestinal permeability is increased. Low-molecular-weight substances may enter the bloodstream and stimulate the formation of circulating immune complexes. These are held responsible for extraintestinal manifestations of yersinosis. Whether these circulating immune complexes and antibodies against Y. enterocolitica have an effect on the inner ear remains unclear. CONCLUSION: Because the coincidence of yersiniosis and a bilateral vestibular loss with no other identified cause, a postinfectious immune response is suggested as possible pathogenic mechanism.