[Teleteaching in otorhinolaryngology (part 1). Real-time transmission of a congress in picture and tone into the Internet]

The transmission of scientific seminars into the Internet represents a new application of modern technologies for teleteaching. We digitally recorded 74 seminars and discussions during the 8th annual meeting of the German Society of Skull Base Surgery with five cameras and eight microphones, and transformed the data live with the real-Producer using a video card.This transferred data stream was sent via ISDN (128 kbit/s) to a real-server at the university, which was used for distribution in the net. The seminars could be called up in the display format of 320x240 pixels with a delay of 3 min (minimum: 30 s, as a function of the connection of the user) at each computer with Internet entrance. Altogether,we registered 3,284 accesses to the presentations following the congress until June 2002. The quality of picture transmission (24-36 kbit/s) and the quality of tone (audio stream: 5 kbit/s) were sufficient to understand the contents of the slide, video or computer presentation. The transmission of scientific meetings into the Internet can increase, with a justifiable technical expenditure, their efficiency by the ubiquitous availability of the information and the extension of the audience.

[Fantoni translaryngeal tracheotomy (TLT) with rigid endoscopic control]

RATIONALE

The incidence of translaryngeal tracheotomy (TLT)-associated peri- and postoperative complications should be assessed prospectively.

METHODS

TLT was carried out in operation-theatre under rigid endoscopic control. Peri- and postoperative complications, decanulement and late sequelae were assessed in ENT-patients. In patients of other wards only perioperative complications were evaluated.

RESULTS

41 patients (26 ENT-patients, 15 patients of other wards) were tracheotomised by TLT. Perioperatively, we observed 3 technical problems (accidental pulling through of the tracheostomy tube). In 2 of these cases TLT could be completed without problems, in 1 case TLT was converted to surgical tracheotomy. Postoperatively, we could find no complications in 26 ENT-patients. Decanulation took place after 7 days on average. We found no tracheocutaneous fistulas or tracheostenoses, scars were unobtrusive.

CONCLUSIONS

TLT with rigid endoscopy is a simple percutaneous tracheotomy-technique with a low complication rate.

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.

The use of open MRI in otorhinolaryngology: initial experience

Intraoperative imaging in head and neck surgery is a useful tool in many situations. In addition to being helpful for intraoperative orientation, real-time imaging enables visualization of the progress of surgery and the completeness of tumor resection. Regions in the head and neck to which access is difficult, and which therefore have a high incidence of morbidity and risk for the patient, can be approached more easily and safely in an open MRI than in a conventional way. Interventions in the open MRI (Signa SP, 0.5 Tesla) were performed with nonmagnetic instruments and an MR-safe microscope. For intraoperative navigation, the integrated FlashPoint system is helpful, because it allows targeting of the tumor by a calculated virtual line. T1W spin-echo, T2W fast spin-echo, and 3D T1W gradient-echo sequences were used for high-resolution imaging. Real-time imaging is achieved by fast multiplanar spoiled gradient-echo sequences or T2 single-shot fast spin-echo sequences. From 1996 to the present, we biopsied 17 petroclival tumors, performed paranasal sinus surgery in five cases, biopsied two neck masses, and inserted tubes for brachytherapy in 12 cases. No complications were observed. In all surgical procedures, a good resolution was obtained with MRI, especially for soft-tissue structures. The tumor could be targeted exactly, and all specimens revealed the relevant histology. In paranasal sinus surgery, however, the success rate was lower because it was difficult to distinguish blood from pathologic tissue. The insertion of tubes for brachytherapy was successful in all cases. It was possible to apply the tubes parallel to each other, 1 cm apart. Relevant biopsies could be taken of both neck masses. The indications for the use of open MRI in otorhinolaryngology are biopsies of tumors in regions that are difficult to approach, such as the petrous apex and petroclival region, the parapharyngeal space, and the orbit. Furthermore, the open MRI can be useful in paranasal sinus surgery, in the evaluation of tissue resection, and in the detection of the anatomy of delicate structures such as the internal carotid artery, the skull base, and the orbit. In addition, active navigation in the open MRI is possible with the integrated FlashPoint system. The advantage over conventional navigation systems lies in the possibility of real-time imaging, which allows detection of tissue changes occurring during the procedure.

[Reconstruction of the frontal bone with individual titanium implants after surgical therapy of osteomyelitis of the frontal bone]

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.

[Parapharyngeal space-occupying lesions. Differential diagnosis based on case examples]

INTRODUCTION

Parapharyngeal tumors account for only 0.8% of all head and neck tumors which often presents the problem of preoperative diagnosis. Up to 80% of parapharyngeal tumors are benign.

PATIENTS

Starting November 1995 to March 2001, 16 patients with parapharyngeal tumors and 1 retropharyngeal abscess were treated. The median age was 54 years. Only 2 patients demonstrated peripheral nerve lesions preoperatively.

RESULTS

17 tumors and the retropharyngeal abscess were excised via transcervical approach, with an extension by parotidectomy and temporary mandibular split in 1 case. Histological entities were pleomorphic adenomas in 5 cases, a ganglioneurinoma, neurinoma of the vagal nerve and metastasis of a squamous cell carcinoma in 2 patients each, furthermore neuroblastoma, extramedullary plasmocytoma, T-cell lymphoma, and hemangioma in 1 patient each.

CONCLUSIONS

We demonstrate the differential diagnosis of parapharyngeal tumors as well as their diagnostic and therapeutic management. The tumors should be excised by a transcervical approach to protect cervical vessels and nerves, which is limited by a transoral approach.

Carcinogen-induced site-specific mutagenesis and genetic susceptibility in squamous cell carcinoma of the head and neck

Tobacco and alcohol have been identified as the most important risk factors for squamous cell carcinomas of the head and neck (HNSCC). Especially for tobacco, some of the carcinogen-induced mutations that trigger transformation have been identified. Much attempt has been made to show a relationship between the mutations of growth regulatory genes, i.e. tumor suppressor- or oncogenes, and the exposure to specific exogeneous mutagens. One of the best examined genes - harboring the most DNA damages (DNA adducts) - caused by xenobiotics is p53. This tumor suppressor gene is an important regulator of cell cycle and apoptosis and is mutated in 40-60% of all HNSCC. Further studies link specific mutations of the ras oncogene to definite carcinogens. The question of why these mutations lead to cancer in some smokers but not in others, i.e. the individual's susceptibility to external carcinogens, remains unclear. One possibility is the individual's ability (or non-ability) of detoxifying carcinogenic xenobiotics or repairing the DNA damages they caused. There are several known polymorphisms of enzymes involved in detoxification as well as in DNA repair - which might explain the interindividual variable susceptibility to HNSCC in smokers and drinkers. However, the results of several examined polymorphisms are diverse or even controversial. The diversity might be due to ethnical differences, study populations, tumor localizations as well as intratumoral heterogeneity. In this review, we attempt to discuss the carcinogen-specific mutations as well as the genetic polymorphisms, which may transfer an enhanced susceptibility to suffer HNSCC.

Analysis of minimal sample volumes from head and neck cancer by laser scanning cytometry

BACKGROUND

The increasing diversity in therapeutic strategies in head and neck oncology is dependent on the development of equally appropriate diagnostic tools. A growing number of diagnostic procedures is intended to be performed on an out-patient basis. In this context, analyses of hypocellular specimens such as fine-needle aspirate biopsies (FNABs) or swabs are very important: There are minimal side-effects, and they can be analysed within hours.

MATERIAL AND METHODS

Laser scanning microscopy (LSC) is a microscope-based method combining the advantages of flow cytometry and image analysis: In addition to the fluorescence data of each individual cell, its morphology can be documented by re-staining with a conventional cytological staining. Any cell can then be re-localised in the microscope for direct observation. FNABs and swabs are incubated in PBS, erythrocytes are lysed, and cells are mounted on slides. After fixation in ethanol, cells are stained for cytokeratin by indirect immunolabelling and for DNA by propidium iodide. Analysis by LSC is performed to determine the ploidy of the epithelial cells. For immunophenotyping of peripheral blood in cancer patients by LSC 20 microl full blood are stained for CD antigens by direct immunolabelling and for DNA by 7-aminoactinomycin D.

RESULTS

FNABs and swabs were taken from 150 malignancies of different sites in total; all specimens yielded sufficient cells (>5,000). 30 tumours of the parotid gland were analysed in detail: Out of 9 malignant tumours 8 showed aneuploidy, whereas all 21 benign tumours were diploid. Immunophenotyping in 23 tumour patients showed a significant reduction of lymphocytes in the peripheral blood as compared to healthy individuals.

CONCLUSIONS

Further studies have to be performed to validate the analysis of hypocellular specimens by LSC and to determine its role in routine clinical work. Its potential is most evident in tumours that are not accessible for open biopsy such as those of the parotid gland or the larynx.

[Reconstruction of hypopharynx after pharyngolaryngectomy with U-shaped radial forearm flap]

BACKGROUND

After pharyngolaryngectomy reconstructive procedures of the upper digestive tract are necessary. Since the introduction of microvascular tissue transplantation jejunal loops proved to be a versatile transplant. Nevertheless it has some disadvantages as i. e. the increased donor morbidity, a rather high sensitivity to hypoxia and the tendency of shrinkage and formation of stenosis.

METHOD

We perform the reconstruction of the hypopharynx with the radial forearm flap. The fasciocutaneous flap is harvested on the radial artery in a size of 12 x 6 cm in average and is sutured U-shaped paramedian to the prevertebral fascia. In addition the posterior wall of the oesophagus and the oropharynx have to be adapted to the prevertebral fascia.

RESULTS

Between 1997 and 2001 we performed these reconstructions in 20 patients. In one case we found a complete flap necrosis, which required secondary reconstruction with a pectoralis major flap. In 2 patients we saw a stenosis at the junction to the oesophagus, which was treated by revision surgery and bougienage. In 18 patients swallowing was regular. 6 patients were able to learn oesophageal speech.

CONCLUSION

The radial forearm flap in its U-shaped transposition to the prevertebral fascia represents a functionally good reconstructive procedure for the hypopharynx.

CT and MR imaging after middle ear surgery

This article describes the current value of imaging in patients after stapes surgery and surgery after chronic otitis media including cholesteatoma. Possibilities and limits of computed tomography (CT) and MRI are described and most important investigation parameters are mentioned. After otosclerosis surgery, CT is the method of first choice in detection of reasons for vertigo and/or recurrent hearing loss in the later postoperative phase. CT may show the position and condition of prosthesis, scarring around the prosthesis and otospongiotic foci. Sometimes, it gives indirect hints for perilymphatic fistulas and incus necrosis. MRI is able to document inner ear complications. CT has a high negative predictive value in cases with a free cavity after mastoidectomy. Localized opacities or total occlusion are difficult to distinguish by CT alone. MRI provides important additional information in the differentiation of cholesterol granuloma, cholesteatoma, effusion, granulation and scar tissue.

Case report. Mycotic arteritis due to Aspergillus fumigatus in a diabetic with retrobulbar aspergillosis and mycotic meningitis

A 74-year-old man with diabetes mellitus type II, retinopathy and polyneuropathy suffered from exophthalmus, ptosis and diplopia. Magnetic resonance imaging and computer tomography showed a space-occupying process in the right orbital apex. An extranasal ethmoidectomy accompanied by an orbitotomia revealed the presence of septated hyphae. Aspergillus fumigatus was grown from the tissue. After surgical removal of the fungal masses, therapy with amphotericin B (1 mg kg(-1) body weight) plus itraconazole (Sempera, 200 mg per day) over 6 weeks was initiated. Five months later the patient's condition deteriorated again, with vomiting, nausea and pain behind the right eye plus increasing exophthalmus. Antifungal therapy was started again with amphotericin B and 5-fluorocytosine. Neutropenia did not occur. The patient became somnolent and deteriorated, a meningitis was suggested. Aspergillus antigen (titre 1:2, Pastorex) was detected in liquor. Anti-Aspergillus antibodies were not detectable. Both the right eye and retrobulbar fungal masses were eradicated by means of an exenteratio bulbi et orbitae. However, renal insufficiency and an apallic syndrome developed and the patient died. At autopsy, a mycotic aneurysm of the arteria carotis interna dextra was detected. The mycotic vasculitis of this aneurysm had caused a rupture of the blood vessel followed by a massive subarachnoidal haemorrhage. In addition, severe mycotic sphenoidal sinusitis and aspergillosis of the right orbit were seen, which had led to a bifrontal meningitis.

Swallowing function after endoscopic resection of supraglottic carcinoma with the carbon dioxide laser

From April 1998 to May 2000, 14 patients with supraglottic cancer underwent transoral laser surgery (T-stage T1-2: 11 patients, T3: 3 patients). In three patients, an epiglottectomy or hemi-epiglottectomy was performed. In 11 patients, further structures (false cords, the valleculae and the base of the tongue and/or parts of the arytenoid cartilage) had to be resected. Thirteen patients had to undergo neck dissection and post-operative irradiation. Tracheostomy was carried out prophylactically in two cases. Every patient received a nasogastric tube perioperatively. One week after surgery, an evaluation of dysphagia was performed by video endoscopy (VEED). Aspiration was the main problem; in no case did dysphagia occur. The aspiration was graded according to videolaryngoscopical classification. Four patients had an occasional and ten patients a permanent aspiration after surgery. According to this assessment, an individual deglutition therapy management was established. Ten patients with permanent aspiration received a temporary percutaneous endoscopic gastrostomy (PEG) and were integrated in a rehabilitation programme (stimulation of the swallowing reflex, training of compensatory swallowing manoeuvres, dietary regime). Due to this training programme, the PEG could be removed in eight patients after 2-9 months. No patient needed a laryngectomy or a tracheostomy due to aspiration. There were no cases of aspiration-associated pneumonia. To obtain satisfying functional results after transoral laser surgery of supraglottic cancers with resection of the epiglottis, post-operative deglutition management, consisting of video endoscopy, a training programme and often a PEG, is necessary.

Bone marrow transfer from wild-type mice reverts the beneficial effect of genetically mediated immune deficiency in myelin mutants

Inherited demyelinating neuropathies are chronically disabling human disorders caused by various genetic defects, including deletions, single site mutations, and duplications in the respective myelin genes. We have shown in a mouse model of one distinct hereditary demyelinating neuropathy (heterozygous P0-deficiency, P0+-) that an additional null mutation in the recombination activating gene-1 (RAG-1--) leads to a substantially milder disorder, indicating a disease modifying role of T-lymphocytes. In the present study, we addressed the role of lymphocytes in the mouse model by reconstituting bone marrow of P0+-/RAG-1-- mice with bone marrow from immunocompetent wild-type mice. We compared the pathology and nerve conduction in double mutant mice (P0+-/RAG-1-- on a C57BL/6 background) with that in double mutants after receiving a bone marrow transplant. We found that the milder demyelination seen in the lymphocyte-deficient P0+-/RAG-1-- mutants was reverted to the more severe pathology by reestablishing a competent immune system by bone marrow transfer. These data corroborate the concept that the immune system contributes substantially to the pathologic process in this mouse model and may open new avenues to ameliorate human hereditary neuropathies by exploiting immunosuppressive treatments.

[Value of magnetic resonance tomography for interventions in the ENT specialty]

PURPOSE

Presentation of new concepts and applications of MR-guided head and neck surgery are presented. Examples of diagnostic and therapeutic procedures such as evaluation of transseptal tumor biopsies, placement of afterloading catheters for brachytherapy, and microscopic surgery of paranasal sinuses in the open MRI are discussed.

MATERIAL AND METHODS

24 MRI-guided ENT-procedures (14 transsphenoidal biopsies, one transnasal biopsy, 6 placements of brachytherapy catheters, and 3 operations of the paranasal sinuses) were performed in an open 0.5 T MR system.

RESULTS

Localisation and/or extension of all lesions as well as the placement of biopsy needles or catheters were determined with great precision during the interventions.

CONCLUSIONS

Surgical risk and postoperative morbidity are significantly reduced in MR-guided surgery of the petroclival region and the region of head and neck compared to other, conventional methods. Thus, interventional MRI-guidance optimizes minimal invasive surgery and catheter placement in difficult anatomical regions like the petroclival region.

Magnetic Resonance Imaging???Guided Biopsies of the Petrous Apex and Petroclival Region

OBJECTIVE

To analyze the advantages in safety and precision of biopsies of the petrous apex and petroclival region using open magnetic resonance imaging (MRI).

SETTING

The University of Leipzig Medical Center.

PATIENTS

Biopsies were taken in 13 patients with tumors of the petrous apex and petroclival region.

INTERVENTION

With the patient in the 0.5-T intraoperative MRI system (Signa SP; General Electric Medical Systems, Boston, MA, U.S.A.), biopsies were taken from the petrous apex and the petroclival region under imaging control by transseptal, transsphenoidal access. The region of interest was approached with a virtual pointer (Flashpoint Position Encoder; Image Guided Technologies, U.S.A.) and marked with a gadolinium-filled pointer.

RESULTS

In all patients, the authors obtained enough tissue for histologic study, which also proved to be the suspected tumor. One patient had a bone cyst, another had a malignant lymphoma, and another two a cholesterol granuloma originating from the petrous apex. Three other patients had metastases (carcinoma of the breast, bronchial carcinoma, and unknown origin). Three patients had a meningioma, and another three a chordoma. The authors did not see any postoperative complications.

CONCLUSIONS

In the authors' experience, the transsphenoidal access is favorable for approaching and sampling lesions of the petrous apex and the petroclival region. This route, however, is disadvantageous because the course of the internal carotid artery and the brainstem narrow the surgical space to the petrous apex. Open MRI in these cases is very useful because it allows a safe approach to the tumor by navigation and by visualizing the anatomic structures in real-time imaging.

CUP (carcinoma of unknown primary) syndrome in head and neck: clinic, diagnostic, and therapy

BACKGROUND

Up to 10% of all cervical lymph node metastases present without a known primary site. Between 70 and 80% of the found primary tumors are located in the head and neck region, because cervical lymph nodes represent the lymph drainage of the head and neck.

PATIENTS AND METHODS

We demonstrate the clinic, diagnostic management and therapy of carcinoma of unknown primary (CUP) in this retrospective study of 75 patients who primarily presented cervical metastases with unknown primary tumor at the Otorhinolaryngological Department of the University of Leipzig, Germany.

RESULTS

A primary tumor was found in 44% of the patients, and 76% of the primary tumors were localized in the head and neck region. The overall 5-year survival rate was 13.3%. The 34 patients with pretherapeutically detected primary tumors showed a tendency towards better survival, with a 5-year survival rate of 21% compared to 10% in patients with undetected primary.

CONCLUSIONS

Following a thorough physical examination, radiologic imaging, i.e., computed tomography and/or magnetic resonance imaging, of the head and neck region as well a chest X ray, panendoscopy with biopsy of the most probable tumor sites, and diagnostic tonsillectomy should be performed. Further diagnostic procedures as gastroenterologic, urogenital and gynecological examinations should be performed, depending on histology and location of the node and under consideration of cost-benefit analysis. Curative treatment should at least include ipsilateral neck dissection and adjuvant irradiation of the complete cervical lymph drainage. In the literature, radiation of the laryngopharyngeal mucosa is still discussed controversially: some authors recommend the irradation of the pharyngeal mucosa extending from the nasopharynx to the upper esophagus, whereas others regard the resulting side effects as too high compared to the expected benefit.

Transnasal and transsphenoidal MRI-guided biopsies of petroclival tumors

Magnetic resonance imaging (MRI) allows excellent tissue characterization in the area of the petroclival region and can depict lesions not visualized with ultrasound or computed tomography (CT). The aim of this study was to demonstrate the clinical feasibility and utility of an interactive MR-guidance system to target and biopsy tumors in the petroclival region. MRI-guided biopsies of 10 patients with tumors in the clivus and petrous apex were performed in an open 0.5-T MR system. Lesions were targeted through a transsphenoidal or transnasal approach. Imaging during biopsies was achieved by a combination of standard and interactive mode. T1-weighted spin-echo, T2-weighted fast spin-echo (FSE), and three-dimensional T1-weighted gradient-echo (GRE) scans (standard mode) were selected to provide optimal tissue characterization for both the lesion and surrounding structures and varied according to the anatomic site. For interactive imaging, T1-weighted GRE and T2-weighted FSE sequences were used. We performed MRI-guided transsphenoidal biopsies in 10 patients who had lesions identified by CT (n = 5) and/or MRI (n = 10). The indications for biopsies were to differentiate between suspected malignant processes (n = 4 ) and benign processes (n = 6). Lesions adjacent to structures like the internal carotid artery were accurately targeted in particular. All biopsies were performed successfully and were the basis for selection of further treatment. No complications occurred during the procedures. An open MR system allows interactive control of biopsies in the area of the petroclival region, providing maximum patient safety and diagnostic accuracy not possible in other systems. The advantages of MRI tissue characterization are combined with an interactive, one-step method of localization and targeting, as well as tissue sampling. J. Magn. Reson. Imaging 2001;13:3-11.

[Quality assurance in ENT tumor surgery]

BACKGROUND AND OBJECTIVE

Quality control is of special importance in head and neck oncology since the quality of medical care constitutes a vital parameter for the diseased patient. In contrast to other medical specialties, no quality assurance program for head and neck cancer patients has yet been established in Germany. Therefore, a survey was conducted to assess the quality assurance instruments that are in use today in otorhinolaryngology-head and neck (ORL-HNS) centers.

PATIENTS AND METHODS

In a nationwide survey, questionnaires were sent out to 146 German ORL-HNS departments (the return rate was 75%).

RESULTS

56% of all departments apply dedicated quality assurance processes, and 38% have appointed a formal quality assurance officer. Interdisciplinary oncological conferences are held in the vast majority of all departments with the participation of radiation oncologists in 86 (78%), medical oncologists in 84 (76%), diagnostic radiologists in 82 (74%), and pathologists in 73 (66%). Morbidity-mortality conferences are held in seven departments (6%). A standardized follow-up of oncological patients is carried out in 95 units (86%), and 53 departments use computer-assisted data bases to organize their follow-up data (48%). A wide variety of documentation systems is in use throughout the country: 78 units (71%) offer formal follow-up to their oncological patients.

CONCLUSIONS

This survey documents a wide-spread interest in quality assurance procedures. Many individual efforts are being undertaken. However, no uniform quality assurance or auditing system is currently in use in Germany nor is a commonly accepted data base available. The ability to offer oncological follow-up within the national social security system is generally considered indispensable for the maintenance of high-quality oncological care in ORL-HNS departments.