Biomedical subjects

G Grevers

Publications and source records attributed to G Grevers.

At least 91 records · Page 5Linked to original sources

PubMed1995

[Vascular, inflammatory and tumorous lesions of the temporal bone and cerebellopontile angle: applications of magnetic resonance tomography].

Advances in high resolution magnetic resonance imaging (MRI) allow the evaluation of the cerebellopontine angle and temporal bone. The purpose of our study was to demonstrate pathological and anatomical aberrations of cerebral arteries in relation to clinical symptoms. The study was carried out on a 1T MR whole body scanner (Impact, Siemens, Erlangen, Germany), using a head coil, a pre- and postcontrast ("Magnevist", Schering, Berlin, Germany) T1-weighted 2D-FLASH sequence and a T2-weighted turbo-spin echo sequence. We examined 22 patients suffering from asymmetric hearing loss, pulse-synchronous tinnitus, hemifacial spasm or facial palsy. The problem of a clear differentiation of meningiomas and acoustic neurinomas by means of MRI is discussed. We identified aberrant AICAs at the cerebellopontine angle in close contact with the V., VII. and VIII. cranial nerve. Inflammatory lesions of the facial and vestibulocochlear nerve were visualised successfully. The potential of the pre- and postcontrast 2D-FLASH sequence for the detection of a wide range of different lesions in the cerebellopontine angle and the temporal bone in MRI of the head was demonstrated.

Arteries↗

PubMed1995

[Sarcoma of the nose and paranasal sinuses].

Sarcomas of the head and neck are rare tumours accounting for less than 1% of all malignant neoplasms in this region. The prognosis of these tumours and the survival in adults (< 50% at 5 years) is directly related to histological tumour type, tumour size and the possibility of adequate tumour resection. In the present paper, the authors present the course of sarcomas with special reference to rhabdomyosarcoma and osteosarcoma in the nose and paranasal sinuses. Surgical resection with pathologically free margins represents the best modality of initial therapy. Additional adjuvant radiotherapy and/or chemotherapy have shown better survival rates in pediatric patients and, to some degree, also in adults. The purpose of future studies should be the development of new therapy protocols which could further elucidate the beneficial effects of adjuvant therapy in the treatment of sarcomas of the head and neck.

Adolescent↗

PubMed1995

[Malignant melanomas of the nasal cavity and paranasal sinuses].

Mucosal melanomas of the nose and paranasal sinuses are rate tumours (2.4-4% of all malignancies in this area) with a poor prognosis. The increasing number of cutaneous melanomas during the last decades gave rise to determine the occurrence of mucosal melanomas of the nose and paranasal sinuses in our department between 1987-92. During this time, 6 patients with malignant melanoma of the nose and paranasal sinuses were seen in our department, representing 11% of all patients (55) with malignant tumours in this region. In five cases surgery was performed (with two patients receiving postoperative radiotherapy); one patient was treated primarily with irradiation. The mean survival time was only 19 months, which--from the authors' point of view--was mainly due to the extension of the tumours. The findings of this study might indicate an increase of malignant melanomas of the nose and paranasal sinuses; however, the number of patients is too small for a final statement on this matter.

Aged↗

PubMed1995

[Primary radiotherapy of nasopharyngeal carcinoma].

One hundred twenty-one patients treated for nasopharyngeal carcinoma with radiation therapy were analyzed; 85 were male, 36 were female. Twenty-one percent had tumour stage T0/T1; 32.5%, T2; 27.5%, T3; and 19%, T4. In 75% of the cases, the lymph nodes were involved. Twelve patients underwent a neck dissection. Histology showed squamous cell carcinoma in 38%, lymphoepitheloid carcinoma in 41.4%, undifferentiated carcinoma in 19%, and adenocarcinoma in 2%. Beginning in 1980, a modified radiation technique with large portals and an increase of the dose from 57.1 Gy to 61.5 Gy targe volume dose was used. Five year overall survival was 32.1%, recurrence-free survival, 30.7%; and local recurrence free survival, 45.8%. Age, sex, and T stage had no significant influence on survival. Multivariate analysis (Cox model) showed that involvement of the lymph nodes, histology, and the new irradiation technique with the higher total dose significantly influenced survival.

Adenocarcinoma↗

PubMed1995

[The value of MRT in primary extramedullary plasmacytoma involvement of the head-neck area].

Six patients with a primary extramedullary plasmocytoma in the head and neck were examined using MR imaging. The morphological appearance of these lesions was described to support the radiologist in the differential diagnosis of this rare lesion. All tumours appeared as oval-shaped and sharply delineated without any signs of infiltration. After contrast media application a distinct central inhomogeneity could be proved in all cases. Furthermore, demoscopical, clinical and therapeutical problems were discussed based on the literature.

Combined Modality Therapy↗

PubMed1995

[Pulsatile tinnitus as a key symptom of glomus tumor: diagnostic value of magnetic resonance tomography].

The aim of this study was to evaluate the diagnostic value of modern imaging tools in pulsatile tinnitus, which might be apparent in a variety of different diseases. While computed tomography (CT) and digital subtraction angiography (DSA) have been the methods of choice in the diagnostic management of this symptom and its related diseases, the technical progress in the development of MRI and MRA highly recommends these techniques as additional yet sufficient imaging tools. The authors demonstrate 2 representative cases of pulsatile tinnitus (one patient with glomus tumour, one patient with jugular bulb deformity) and the adequate diagnostic procedure in terms of imaging tools. It is concluded that a routine MRI-examination might allow a diagnosis with high sensitivity and specificity. Still, digital subtraction angiography and computed tomography remain indispensable in the diagnostic management of pulsatile tinnitus.

Adult↗

PubMed1995

[A new surgical system for endoscopic paranasal sinus surgery].

Functional endoscopic sinus surgery (FESS) is the treatment of choice in the majority of chronic inflammatory diseases of the paranasal sinuses. Currently used surgical instruments for FESS are based on a "grab and tear"-approach, thus predisposing to increased bleeding--especially in nasal polyps--which can significantly reduce the visual field and might lead to consecutive complications, including the injury of the anterior skull base and optic nerve. In the present paper the author introduces a new surgical system, invented by Setliff and Parsons (8), which enables the rhinosurgeon to operate in a near-bloodless field, thus providing an unimpaired vision for a safer approach to the paranasal sinuses. In addition, the system ensures meticulous cutting of tissue instead of tearing, which also reduces the risk of complications. Our experiences with the "micro debrider system" have confirmed the usefulness of this instrumentarium, especially in the operative management of nasal polyps, in terms of less traumatic surgery and better visual field, thus implying fewer complications during FESS.

Debridement↗

PubMed1995

[Fordyce spots. A little regarded finding in the area of lip pigmentation and mouth mucosa].

Sebaceous glands on the vermilion border of the lips and the oral mucosa are common in adults. Only pathologic sebaceous glands visible through the epithelium should be regarded as Fordyce's granules. The incidence of Fordyce's granules increases from childhood to adulthood, and is slightly higher in men. The most prevalent sites are the vermilion border of the lips and the buccal mucosa. Fordyce's granules usually have the same histological features as cutaneous sebaceous glands. Pathologic alterations are rare. There is no significant correlation between Fordyce's granules and systemic diseases.

Adolescent↗

PubMed1995

Intervascular smooth muscle fibers and muscular bolsters in nasal swell bodies of humans.

There is strong clinical evidence that the cavernous tissue (swell bodies) of nasal mucosa plays an important role in congestion of the nose. Still, the complex mechanisms responsible for the unique behavior of these vessels have not yet been identified, and even the morphology of these structures is still a matter of controversy. The present study was performed on nasal mucosal specimens from inferior turbinates of humans by means of histology and transmission electron microscopy. Besides the evaluation of the vascular wall structure of the nasal swell bodies, special attention was given to two morphological peculiarities: intervascular smooth muscle fibers and muscular bolsters. Intervascular smooth muscle fibers are composed of bundles of smooth muscle cells varying in diameter between 14 and 35 microns; they are attached to the muscular coat of the vessels of the cavernous tissue. Muscular bolsters are distinct protrusions of the vascular wall in nasal swell bodies; they are found not only at the transition between different vessels, but also irregularly within the course of veins of the cavernous tissue. The authors report on their understanding of the functional significance of intervascular smooth muscle fibers and muscular bolsters within the cavernous tissue for swelling mechanisms in the nose and discuss their results in light of the literature.

Connective Tissue↗

PubMed1994

A comparison of clinical, pathological and radiological findings with magnetic resonance imaging studies of lymphomas in patients with Sjögren's syndrome.

In the past few years a variety of papers on magnetic resonance imaging (MRI) of the salivary glands have been published, mainly focusing on the evaluation of salivary gland tumors. More recently, non-tumorous lesions have also been examined with this imaging technique. In Sjögren's syndrome (SS) a characteristic inhomogeneous pattern with a "honeycomb-like" appearance of the parotid gland tissue has been shown in the T2-weighted sequence. This study shows MRI findings in four cases of intraglandular lymphoma occurring in patients with SS. Four patients with suspected lymphomas were examined with MRI, following which all lesions were either biopsied or removed. This enabled us to correlate clinical, radiological and pathological findings. Results indicate that MRI is a useful imaging tool in the detection of intraglandular lymphatic infiltrates, although it is not possible to distinguish morphologically between a localized lymphatic infiltrate and an early stage malignant lymphoma. Nevertheless, MRI is considered to be a valuable non-invasive method for deciding whether or not to perform a biopsy. Due to the excellent soft tissue differentiation obtained, it is also helpful for the surgeon to plan and perform a successful biopsy with minimal risk to the facial nerve.

Aged↗

PubMed1994

[Site-specific, structural and ultrastructural characteristics of endonasal cavernous tissue exemplified by the inferior turbinate in man. Light and transmission electron microscopy study].

The cavernous tissue of the nose has been studied morphologically for now more than 150 years. Even though the majority of new findings was already described in the second half of the last century and is associated with scientists like Kölliker, Kohlrausch and Zuckerkandl. The vascular structures, usually described as "cavernous tissue" or "swell bodies" are located in different parts of the nasal mucosa, but mainly in the inferior turbinate. In the present paper the author demonstrates the results of his studies on the structure and ultrastructure of smooth muscle components of nasal swell bodies based on light - and transmission-electron microscopic findings. Light microscopic observations already reveal the differences in vascular wall structure between areas adjacent to the epithelium and those parts of the vessels located in the deeper parts of the tunica propria. Ultrastructural examination shows differences in size and density of smooth muscle cells in different parts of the cavernous tissue; it also demonstrates the variant appearance of the basal lamina of these muscle cells. The results are discussed and compared with the appropriate literature.

Endothelium, Vascular↗

PubMed1994

[Immunohistochemical study of the neuroanatomy of the nasal turbinate in man. Innervation pattern of the blood vessels].

The complex vasculature of the human nasal mucosa plays an important role in the protection of the lower respiratory airways. It has to react to different external and internal stimuli and is under control of the autonomic nervous system. The aim of our study was to detect the precise localisation of neural structures in human nasal mucosa vessels under physiological conditions. Silver impregnation and histochemical staining techniques only allowed a partial aspect of autonomic innervation. Modern immunostaining methods with antibodies to neuron-specific enolase (NSE) and S-100 protein proved to be better for the demonstration of nerve structures. Tissue samples were taken from inferior turbinates received at mucotomy in 42 patients. After fixation the samples were embedded in paraffin wax and cut into serial sections. Additionally frozen sections were performed. The immunocomplexes were visualised by the avidin-biotin-complex (ABC) or by the alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. A high density of S-100 and NSE immunoreactivity of neuronal and glial components of autonomic innervation could be demonstrated in the vessels of human nasal turbinates. Branching off relatively thick nerve bundles of the lamina propria fibres extended to the adventitia of the arteries near the periost and formed a periarterial nerve plexus. Fibres of this plexus supplied the smooth muscle tissue of the tunica media. Around veins only a few single nerve fibres could be demonstrated. By using immunocytochemical techniques it is possible to correlate the localisation of the classical neurotransmitters and multiple vasoactive neuropeptides with the corresponding innervation structures of the complex vasculature in human nasal mucosa.

Adult↗

PubMed1994

[The myofascial pectoralis major flap for tissue replacement in the oral cavity].

Since the original description by Ariyan, the myocutaneous pectoralis-major-(p.m.-)flap has been widely used for soft tissue replacement in the head and neck. In our department this flap has been established as a reliable and versatile method for soft tissue replacement in a variety of tumour defects. In the oral cavity a great number of different surgical procedures have been described for reconstruction of soft tissue defects. However, most surgeons still seem to be using either myocutaneous p.m.-flaps or the so-called "free flaps" (radial forearm flap, free jejunal flap). Authors advocating the "free flaps" usually emphasize the disadvantages of the myocutaneous p.m.-flap (bulk of tissue in the neck and at the recipient site, possible hair-bearing skin, alteration of breast position). During the last two years we have been adding the myofascial p.m.-flap to our surgical repertoire for soft tissue replacement in the oral cavity, because of its lack of disadvantages mentioned for the myocutaneous version. Our experience with the myofascial p.m.-flap for intraoral reconstruction in 14 patients with squamous cell carcinomas of the anterior floor of mouth (8) and tongue (4) are described and discussed in comparison with the "free flaps" used in this region.

Carcinoma, Squamous Cell↗

PubMed1994

[High resolution magnetic resonance tomography of the temporal bone].

Computed tomography (CT) has long been the method of choice for investigations of the temporal bone. Advances in high resolution magnetic resonance imaging (MRI) enabled MRI of the temporal bone. The purpose of this study was to assess detailed reconstruction of the anatomy of the temporal bone by MRI. Healthy volunteers were examined on a 1T MR whole body scanner (Impact, Siemens, Erlangen, Germany). A Helmholtz-configurated head coil was used. A T1-weighted 2D-FLASH sequence (TR = 400 ms, TE = 10 ms, 90 degrees flip angle, 2 mm slice thickness, 180* 256 matrix, 160 mm FOV) was performed pre- and postcontrast as well as a T2-weighted turbo spin echo sequence (TR = 6300 ms, TE = 112 ms, 3 mm slice thickness, 200 mm matrix, 200 mm FOV). A sagittal and an angulated paraxial projection, parallel to the nasopharyngeal edge of the clivus, were chosen. We suceeded in imaging the facial nerve along its entire course, including the geniculate ganglion and the greater superficial petrosal nerve, the cochlear nerve and the vestibular nerve (superior and inferior part). The facial nerve was visualised continuously from the cerebellopontine angle to the foramen stylomastoideum. The delineation of the different turns of the cochlea, the vestibule and the semicircular canals was excellent. High resolution MRI promises to be of great value in the diagnosis of the temporal bone.

Cochlea↗

PubMed1994

[Manifestation of Urbach-Wiethe syndrome in the ENT area].

Urbach-Wiethe's syndrome (hyalinosis cutis et mucosae) is a rare genetic defect of probably autosomal recessive origin. The exact nature concerning the pathogenesis of this disorder is still controversial. A characteristic symptom in early childhood might bei hoarseness, later on manifestations with hyalin deposits in the larynx, oral cavity and oropharynx might occur as well as yellowish-white papular deposits in the skin. The overall prognosis of this disease is good, therapeutic intervention might be necessary for functional purposes (narrowing of the laryngeal lumen) and consists of surgical removal of the lesions.

Adolescent↗

PubMed1994

[The morphology of endonasal cavernous tissue with special reference to muscular cushion formation. A light and transmission electron microscopy study].

Nasal "cavernous" tissue is widely accepted as a key structure for the tumefactive mechanism inside the nose; still there is no common understanding of the structural composition of this special tissue. In the present paper the authors demonstrate the results of their histological and transmission electronmicroscopic findings in human nasal "cavernous" tissue, especially referring to the structural and ultra-structural pattern of the so-called muscular pads or "cushion". Serial sections revealed that these structures occur at the transition of communicating vessels; their muscular coat shows a different and irregular pattern, compared to the vascular wall structure of other parts of nasal "cavernous" tissue. Ultrastructural examination confirmed the impression of a variable and complex orientation of smooth muscle cells within the muscular "cushions". The cytoplasmic components, however, were the same as in other smooth muscle cells of nasal "cavernous" tissue. Localisation and structure of muscular "cushions" imply their functional significance for tumescence of the nasal mucosa in a variety of rhinological disorders. Therefore, the authors suggest to include these special features in therapeutic considerations on the treatment of congested nose. Evaluation of the neurovegetative regulation of this tissue could be a step in the right direction.

Humans↗

PubMed1994

[Pleomorphic adenoma of the maxillary sinus].

Pleomorphic adenoma is the most common benign tumour of the salivary glands, especially the parotid gland. In the present paper we introduce the rare case of a pleomorphic adenoma of the maxillary sinus in a 82-year-old man who was referred to our outpatient clinic with nasal obstruction and occasional events of nose bleeding. Thorough investigation, using endoscopy and computed tomography, revealed a mass extending from the left maxillary sinus to the nasal cavity; the tumour was removed surgically; pathological examination showed a pleomorphic adenoma with no signs of malignancy.

Adenoma, Pleomorphic↗

PubMed1994

[Fat suppression in contrast-enhanced MRT of the base of the skull and of the head-neck area: its clinical value].

167 patients with abnormalities at the skull base and at the cervical-skull junction were examined by MRT in order to compare a FATSAT technique with T1- and T2-weighted SE sequences before and after intravenous injection of 0.1 mmol Gd-DTPA/kg KG. The diagnostic information from corresponding FATSAT and T1-SE sequences was correlated with the histopathological findings. In 10.7% of patients fat suppression was inadequate and in a further 11.3% of patients chemical shift artifacts limited the diagnostic value. The number of detectable lesions was not increased by the use of FATSAT sequences but visualisation of soft tissue lesions was improved, adding to the diagnostic value under specific conditions. Evaluating by the Friedman and Wilcoxon test showed that the postcontrast FATSAT sequences were markedly superior (p < 0.01) in delineating and contrasting the lesions. The additional use of contrast enhanced FATSAT sequences resulted in improved diagnosis of lesions at the skull base and the facial skeleton.

Adipose Tissue↗