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Biomedical subjects

G Grevers

Publications and source records attributed to G Grevers.

At least 55 records · Page 3Linked to original sources
PubMed1999

Fluorescence staining of laryngeal neoplasms after topical application of 5-aminolevulinic acid: preliminary results.

BACKGROUND AND OBJECTIVE: The prognosis of patients suffering from laryngeal carcinomas can be improved by early diagnosis. Exact demarcation of tumor margins could contribute to an optimum preservation of the larynx. Therefore, the aim of the present study was the evaluation of 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PPIX) fluorescence as a new diagnostic procedure for the detection of laryngeal cancer. STUDY DESIGN/MATERIALS AND METHODS: Sixteen patients with suspected malignancies of the larynx received 0.6 wt% 5-ALA-NaCl solution by means of a medical nebulizer. After a period of 1-2 hours, the patients underwent microlaryngoscopy under white light and fluorescence illumination (lambda(ex) = 375-440 nm). A quantitative analysis of the fluorescence contrast between neoplastic and surrounding tissue was performed using an optical multichannel analyzer. RESULTS: Carcinoma, carcinoma in situ, and dysplasia showed red fluorescence that could be attributed to the 5-ALA-induced formation of PPIX. The surrounding normal tissue exhibited autofluorescence in the green spectral range, which was greatly reduced within the tumor. The results of macroscopic red fluorescence staining were correlated with the histologic diagnosis. CONCLUSION: According to these preliminary results, the presented method seems to be a promising adjunct diagnostic procedure for the early identification of malignant neoplasms in the larynx. The aim of further investigations is the assessment of sensitivity and specificity and an evaluation of fluorescence-guided laser resections of laryngeal cancer. Lasers Med. Surg. 25:414-420, 1999.

Administration, Topical↗
PubMed1999

[Rapidly progressing course of cutaneous angiosarcoma in the area of the head-neck].

INTRODUCTION: Angiosarcomas are rare, aggressive tumors of vascular origin, most commonly affecting older males. An optimum treatment strategy has not yet been defined. CASE REPORT: We report on a 68-year-old male patient who initially presented with a small, bruise-like macule of the cheek. He was treated with different antibiotics and steroids for a few weeks. Due to failure of any clinical improvement, a biopsy was taken revealing an undifferentiated malignant tumor. Subsequently, the patient was referred to our department, where the lesion was excised. Histology showed an extensive, well-differentiated angiosarcoma. According to oncological protocols, the patient underwent 5 cycles of chemotherapy with etoposid, ifosphamid and adriamycine. Despite therapy, tumor size remained unchanged. After therapy was discontinued, tumor growth rapidly proceeded with semicircular infiltration of the right face and neck. A few weeks later the patient died. DISCUSSION: About 50 percent of cutaneous angiosarcomas are found in the head and neck region of the elderly. No clear etiology has been implicated with respect to the origin of this tumor. Traumatic bruises, infections, and allergic reaction may be confused clinically with angiosarcoma. Differential diagnosis also comprises other vascular neoplastic diseases, i.e. lymphangioma, hemangiopericytoma and Kaposi's sarcoma. If complete excision is possible, radical surgery is the treatment of choice. The effectiveness of chemotherapy is unclear. The role of radiation therapy is also under discussion due to the technical problems of administering radiotherapy to the extensive volume at risk. As the late diagnosis adversely affects the prognosis, the importance of early biopsy in suspicious lesions is mandatory.

Aged↗
PubMed1999

[Navigation surgery in diseases of the paranasal sinuses].

BACKGROUND: Since the mid-80s, endonasal sinus surgery has gained significant importance in the treatment of chronic inflammatory sinus disease. Many surgeons have recognized the necessity of developing new methods to increase the safety of this type of surgery. One of the advancements in increasing the safety of endonasal sinus surgery was the development of computer-aided surgical navigation (CAS) systems. METHODS: Since 1996, we have tried several different CAS systems for difficult surgical procedures in sinus and anterior skull base surgery, mainly revision surgery for chronic inflammatory sinusitis and endonasal tumors. During this time, we tried one electromagnetic ("Insta Trak") and two optoelectric systems ("Surgigate" and "Vector Vision"). RESULTS: In our experience, all systems can be used in endonasal sinus surgery; accuracy was satisfactory and varied between 0.1 and 0.5 mm. There were differences with respect to the time of preparation of the system for surgery as well as to the possibility to use different instruments. CONCLUSIONS: Computer-assisted surgical navigation systems today have gained a degree of accuracy which makes them not only suitable but almost necessary, at least for difficult surgical procedures at the anterior skull base, i.e. revision surgery in chronic inflammatory sinus disease. On the long run, these systems will become mandatory for these kinds of procedures. On the other hand, CAS systems cannot substitute thorough anatomical and surgical training.

Computer Systems↗
PubMed1999

[Influence of nasal obstruction on sleep-associated breathing disorders].

BACKGROUND: The influence of nasal obstruction on sleep associated breathing disorders (SABD) and the controversial effects of surgical treatment are discussed. RESULTS: Complete nasal obstruction caused by nasal packing increases SABD, but varies from patient to patient and depends on age and individual anatomy. Especially patients with preexisting obstructive sleep apnea syndrome (OSAS) can develop severe complications. Some authors found a higher frequency of SABD in patients with nasal obstruction due to anatomical alterations, i.e. septal deviation, while others denied this connection. Major causes for the development of SABD in nasal obstruction include certain reflex mechanisms, increased negative inspiration pressure with a tendency for pharyngeal collapse, and transition to transoral breathing. Intermittent dilatation of the nasal valve using stents or tapes will lead to a decrease of nasal airway resistance and might also result in an improvement of SABD according to some studies, while others did not find any improvement. The results of controversial operative treatment in nasal airway obstruction are also described and include complete healing of high degree OSAS, improvement of sleep quality, and elimination of snoring. On the other hand, surgery might also be completely unsuccessful or even induce OSAS. CONCLUSION: As the effect of any kind of nasal operation on SABD is unpredictable from our present knowledge, the decision whether or not nasal surgery is indicated should depend on the individual situation of the patient. If OSAS is suspected, preoperative and post-operative polysomnography should be performed.

Humans↗
PubMed1999

[Pseudoaneurysm of the lingual artery after tonsillectomy. A rare complication].

BACKGROUND: Tonsillectomy is one of the most common surgical procedures in otorhinolaryngology; however, life-threatening complications can occur in rare cases. PATIENTS: We report about a seven-year-old girl who developed a pseudoaneurysm of the lingual artery following elective routine tonsillectomy. RESULTS AND CONCLUSION: Initial ENT examination will reveal a painful cervical mass or unilateral palatal swelling that can easily be misinterpreted as a peritonsillar (or parapharyngeal) abscess. Computed tomography and angiography are indicated to confirm the diagnosis. Bleeding from a pseudoaneurysm of any branch of the external carotid artery represents a serious and life-threatening complication. Surgery is the treatment of choice.

Aneurysm, False↗
PubMed1999

[Role of diagnostic imaging in chronic recurrent parotitis in childhood].

BACKGROUND: Chronic recurrent parotitis represents a disease of still uncertain etiology that can be divided into a childhood and an adult form. Sialography is still the imaging procedure of choice. METHOD: We report about a nine-year-old girl who had had six episodes of parotitis in the past two years. MR sialography is presented as an alternative to conventional sialography. MR was performed with a 1.5 T wholebody tomograph using a high resolution 3D-CISS sequence. RESULTS AND CONCLUSION: MR sialography does not require any contrast medium. It primarily images liquid structures, and the flow of saliva can be adequately demonstrated after stimulation with ascorbic acid. These special features of MR sialography allow its use also during acute episodes of sialadenitis, thus providing a significant improvement over conventional sialography. Furthermore, no overlapping occurs as in conventional summation images, due to the multiplanar reconstruction features.

Adult↗
PubMed1999

Ho:YAG laser treatment of hyperplastic inferior nasal turbinates.

OBJECTIVES: Although preliminary studies about the successful use of the Ho:YAG laser in nasal turbinate surgery have been reported, no clinical study has been performed on this procedure. The aim of this prospective clinical study was to assess the long-term effect of Ho:YAG laser in the treatment of hyperplastic inferior nasal turbinates. METHODS: Eighty-five patients with nasal obstruction who did not respond to conservative medical treatment were treated with a pulsed Ho:YAG laser (wavelength of =2080 nm). Fifty-two of these patients were included in this clinical study and were followed for 1 year. RESULTS: Within the first 2 weeks, nasal obstruction was correlated to the extent of nasal crusting. Six months after laser treatment, the mucociliary function test showed no variation compared with the preoperative measurements. One year after laser treatment 77% of the patients demonstrated improved nasal airflow on rhinomanometry and questionnaire. CONCLUSIONS: Ho:YAG-laser treatment of hyperplastic turbinates can be performed as outpatient surgery under local anesthesia and offers controllable ablation of soft tissue in a short operation time with satisfactory results and excellent patient acceptance.

Feasibility Studies↗
PubMed1998

Embryonal rhabdomyosarcoma of the nose in an elderly patient, case report and review of the literature.

Embryonal rhabdomyosarcoma of the head and neck is very rare in adults. We report on an embryonal rhabdomyosarcoma of the nose, occuring in a 74-year-old female patient presenting with nasal congestion as the only clinical symptom. Suspected to be an amelanotic melanoma, further biopsies and histological examinations provided the correct diagnosis. She first underwent a course of chemotherapy which led to a partial shrinkage of the tumor mass which was followed by a complete resection of the residual tumor mass. Biologic behaviour of this tumor must be fully appreciated as treatment is interdisciplinary. Rhabdomyosarcoma should be considered in the differential diagnosis of tumors of the nose and paranasal sinuses not only in children, but also in adults.

Age Distribution↗
PubMed1997

[Primary radiotherapy of laryngeal carcinoma. An analysis of the therapeutic results and of the the relapse behavior in 283 patients].

PURPOSE: In the treatment of laryngeal carcinoma definitive radiotherapy results in a similar outcome as surgical treatment in the early stages with a lower morbidity rate and good functional results. In fact no randomized studies exist, so far, and the optimal treatment concept for the different stages is not well defined. The following study analyses retrospectively the treatment results and the recurrence data in patients with a squamous cell carcinoma of the larynx treated with definitive radiotherapy. PATIENTS AND METHOD: Two hundreds and eighty-three patients with carcinoma of the larynx were treated with radiation therapy in the department of radiology of the LMU München between September 1971 and June 1986. Twenty-six patients (9.2%) were female and 257 (73.1%) male. The median age was 68.5 years, respectively 70 years. All patients had a histologically confirmed squamous cell carcinoma of the larynx. No true subglottic cases were observed. Forty-one (14.5%) tumors were localized supraglottically, 207 (73.1%) glottically. Thirty-five patients had a T4 tumor with glottic and supraglottic involvement. In 147 patients the histopathological grading was evaluable: 32 tumors were classified as G1, 95 as G2, 15 as G3 and 5 as G4. According to the UICC classification of 1979 25 patients had a carcinoma in situ (Tis), 93 patients had a stage T1, 90 stage T2, 40 stage T3 and 35 stage T4. Two hundreds and thirty-three of 283 (82.3%) had no lymph node involvement. In 50 patients clinically a lymph node involvement was observed. 22 patients had a stage N1, 5 patients stage N2 and 23 patients stage N3. An external beam radiation mostly with cobalt-60 was performed with a mean dose of 61.9 Gy. RESULTS: The 5-years relapse-free survival for the whole group was 61.7%. The probability for "no evidence of disease" (NED) depended on tumor stage and localisation (glottic tumors: Tis/T1 90.5%: T2 59.4%: T3 39.6%: [5-year NED]; supraglottic tumors T1 64.2%: T2/3 28.6%: T4/N3 24.7% [3-year NED]). Other significant prognostic factors besides T-stage were N-stage (NO vs. N1-3: 3-year recurrence-free survival 68% vs. 37.2%, p < 0.001) and histopathologic grading (G1 vs. G3/4: 3-year recurrence-free survival 74% vs. 37.1%, p < 0.01). One hundred and twenty-two (43.1%) patients had a recurrence, which occurred in 75.4% local, in 12.3% loco regional, in 8.2%, with distant metastases and 4.1% combined. In 50 patients with a recurrent disease a salvage therapy was carried out. Thereby 17 patients achieved a complete response. CONCLUSION: Even for the here described negatively selected patient group with a high median age and multimorbidity, good local control rates could be achieved especially in early stages with definitive radiation therapy. In more advanced stages even in elderly patients a combined surgical-radiotherapeutic treatment should be performed.

Aged↗
PubMed1997

[Significance of vascular endothelium for specific functional behavior of nasal mucosa].

BACKGROUND: During the last decade the morphological structure of nasal blood vessels was understood as a functional basis for different physiological and immunological reactions. RESULTS: Under normal conditions the vascular endothelium is involved in many activities including hemostasis, defense reactions, and angiogenesis during repair and pathological events. Most of the required components are synthesized by the endothelium itself, including extracellular matrix components, coagulation reactants, and growth factors. The complex vasculature of the human nasal mucosa plays an important role in the protection of the respiratory tract by generation of nasal fluid under normal and pathologic conditions. Increased plasma exudation in inflammatory processes including increased plasma protein concentrations binds cytokines, mediators, and cell release products and transports them to the respiratory lumen. During inflammation, endothelial cells stimulated by cytokines like TNF (tumor necrosis factor) regulate the recruitment of leukocytes by expression of certain surface proteins, called adhesion molecules. They also secrete chemokines like IL-8 (interleukin-8) and MCP (monocyte chemotactic protein) to increase the affinity of adhesion molecules, spread the leukocyte form to a flat, migrating one, and stimulate cell locomotion. Last but not least, endothelial cells may also act as antigen presenting cells (APC), although antigen presentation by endothelium is not responsible for the generalized homing of T-cells once the response is working. CONCLUSION: The new scientific results on the functional behaviour of vascular endothelium have opened new perspectives for our understanding of nasal blood vessels; it might also stimulate and enable us to search for new therapeutical concepts based on these findings.

Capillary Permeability↗
PubMed1997

[Electron microscopy studies of vascular innervation of nasal mucosa in the human].

BACKGROUND: The distribution of neural structures in human nasal vasculature is still not completely understood. To date, immunocytochemical and histochemical studies of the innervation pattern and neurotransmitter distribution have only been performed using light microscopy. The aim of this study was to verify these results by electron microscopy and to obtain new knowledge of the innervation of the individual vessel types. The target was to determine the role of the different vessels in the swelling mechanism in human nasal mucosa. MATERIAL AND METHODS: Specimens were prefixed in glutaraldehyde and postfixed in osmium tetroxide. After dehydration they were embedded in araldite. Ultrathin sections were cut, contrasted with uranylacetate and lead citrate, and studied under EM. RESULTS: Nasal vasculature is controlled by a dense innervation. Amyelinated longitudinal nerve bundles and smaller axon conglomerates are detected in the arterial adventitia. Capacitance vessels (veins) in general show few nerve structures, which, in contrast to arteries, are also located between the smooth muscle cells. Cushion veins, however, reveal a stronger innervation pattern especially in their muscular swelling. In contrast to smaller arterioles, no axons can de demonstrated in capillaries. CONCLUSION: The density of innervation in arteries and cushion veins seems to indicate that these vessel types are the central neural control point for the swelling mechanism in human nasal mucosa. Capillary function, however, does not seem to be directly influenced by the autonomic nervous system.

Arteries↗
PubMed1997

[Fibroblast growth factor (b-FGF) in serum and urine of patients with head-neck malignancies].

BACKGROUND: The angiogenic peptide basic fibroblast growth factor (b-FGF) has been suggested to significantly promote angiogenesis; a central event for the growth and metastasis of solid tumors. Elevated levels of b-FGF in the serum and urine of patients with various types of cancer have been reported. No information exists about b-FGF levels in patients with primary head and neck cancer. The present study was performed to determine serum and urine levels of b-FGF in these patients. METHODS: b-FGF was quantified in the urine of 50 (62.5%) patients with head and neck cancer as well as 30 (37.5%) patients with diseases unrelated to cancer using an immunoassay with a detection limit of 1.0 pg/ml (FGF basic "Quantikine", DFB00. Biermann GmbH, Bad Nauheim, Germany). Urine was collected from patients before breakfast and centrifuged for 10 min at 1000 g. The supernatants were stored at -80 degrees C until the assay was performed. RESULTS: In the serum and urine of all patients, b-FGF was detectable by immunoassay. Cancer patients revealed significant increased serum b-FGF concentrations, in addition, advanced tumor size (T3/4) showed significant increased b-FGF levels in both serum and urine. There seems to be a correlation between serum b-FGF concentrations with degree of histologic differentiation. CONCLUSION: The results of this study demonstrate that b-FGF levels are elevated in serum and urine of patients with primary head and neck cancer. These findings suggest an involvement of b-FGF in the formation of solid tumors. The value of b-FGF as a non-invasive monitoring of treatment response in cancer therapy, the correlation with angiogenesis in histologic sections as well immunohistochemical detection are the aim of further investigations.

Adult↗
PubMed1997

[Diagnostic imaging in otorhinolaryngology--assessment of current status].

BACKGROUND: The first conventional x-rays of the paranasal sinuses were received in 1897, just two years after the detection of x-rays. During the following decades several modifications and extensions of conventional radiologic techniques were developed, but routine imaging procedures of the head and neck were mainly restricted to pictures of the paranasal sinuses and the temporal bone. In the fifties, tomography was developed, which gave us a more detailed insight of the anatomy and pathology of the paranasal sinuses and temporal bone. During the last two decades the development of new techniques, i.e. computed tomography (CT) and magnetic resonance imaging (MRI), has significantly increased the importance of modern imaging for the diagnostic evaluation of head and neck diseases. These diagnostic tools enable us to visualize anatomical structures and pathological entities with an accuracy never been expected beforehand. The pace of the improvement of these diagnostic tools, however, requires that both radiologist and otorhinolaryngologist keep up with the adequate indications of CT and MRI in the different areas of the head and neck. A close relationship and cooperation between radiologist and ENT surgeon is therefore indispensible for a fruitful and cost-effective use of modern imaging. Otherwise the patient is exposed to modern medical technology without an equivalent benefit. The purpose of the present paper is mainly to give an update and state of the art of modern imaging techniques in otorhinolaryngology, head and neck surgery. Different areas i.e. paranasal sinuses, temporal bone, salivary glands, oral cavity and oropharynx as well as the neck are discussed in terms of adequate indications for modern imaging in the diagnostic evaluation of different lesions.

Angiography↗