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Biomedical subjects

M Kautzky

Publications and source records attributed to M Kautzky.

35 records · Page 2Linked to original sources
PubMed1993

[Holmium:YAG laser surgery of nasopharyngeal cancer].

A pulsed Holmium:YAG-laser (lambda = 2,120 nm) was used for the first time clinically in tumour surgery. The primary lesion of a transitional cell carcinoma of the nasopharynx with metastatic disease in the neck (T2N2Mo) was laser resected in a photoablative manner with a minor thermal component without danger of damage to the skull base. Neck dissection was performed by conventional surgery. In comparison to laser types depending primarily on the thermal effects of laser-tissue interaction the coagulative necrosis zone following Holmium:YAG-laser surgery is small and there is no area of carbonisation. Macroscopic wound healing showed no complications and was completed after three weeks. At this time radiation therapy was started. The results of the histological examination and the physical properties of this new infrared laser system are discussed as well as the possibilities of flexible fiber Holmium:YAG endoscopic laser tumour surgery in clinical use.

Carcinoma, Transitional Cell↗
PubMed1993

[Plasmacytoma of the nose and paranasal sinuses with intracranial and orbital extension].

A rare case of a solitary extramedullary plasmocytoma of the nasal cavity and the paranasal sinuses with orbital and intracranial extension of a 61-year old male patient was examined clinically, histologically and immunohistologically. The interrelationship of the generalised disease (multiple myeloma = MM) and the solitary extramedullary form (extramedullary plasmocytoma = EMP) is discussed as well as the importance of the magnetic resonance imaging in the diagnosis of tumours of the facial part of the skull.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Are laser-resistant endotracheal tubes safe with the new holmium:YAG infrared laser?

Laser-induced ignition of the endotracheal tube is the most morbid event that may occur during laser surgery of the upper respiratory/digestive tract. The efficacy of two new laser-resistant endotracheal tubes, the Laser-Flex stainless steel tube by Mallinckrodt and the Laser-Shield II tube with teflon-aluminium-silicone coating by Xomed-Treace, was studied under exposure to a newly introduced pulsed infrared laser (holmium:YAG, lambda = 2120 nm) in an experimental setting. The time from the onset of exposure until tube perforation was recorded. Laser exposure was continued for up to 180 s unless tube ignition occurred. Temperature during the following 30 s laser application was measured close to the target zones. The irradiance level of the holmium:YAG laser was in the range required for photoablation and plasma formation and led to laser-induced tube ignition in both types of tube. The steel tube showed greater resistance to laser-induced wall damage than the teflon-aluminium silicone tube. The maximum temperature increase following laser exposure was moderate in both tubes; the mean rise of 10 degrees C for the Laser-Shield tube and 23 degrees C for the Mallinckrodt tube correlating with the physical effects of photoablation.

Aluminum↗
PubMed1992

[Holmium:YAG and erbium:YAG infrared laser osteotomy].

The in-vivo bone ablation characteristics of a pulsed solid-state erbium:YAG laser were compared to those of a pulsed solid-state holmium:YAG laser. Partial osteotomies in the maxillary, the mandibulary, and the nasal bones of white rats were performed. The tissue response was examined by light microscopy. Thermal gradients following the laser application were also measured. Over all energy levels tested the erbium:YAG laser produced ablation of bone with minimal thermal damage to the adjacent tissue. The results of this study are promising for future application of the infrared holmium- and erbium:YAG lasers in otorhinolaryngology.

Animals↗
PubMed1992

[Holmium:YAG infrared laser and UV-Excimer. Laser effects on oral mucosa].

The in-vivo tissue ablation characteristics of a pulsed infrared laser (Holmium:YAG, lambda = 1980) and a pulsed excimer laser (XeCl, lambda = 308 nm) were studied. The holmium laser energy was coupled into nylon fibres. The excimer laser energy was coupled into quartz fibers. Laser incisions were made on white rats at different sites of the tongue. Power settings of 400 mJ per 2.5 microseconds pulse at 5 pulses per second for the holmium:YAG laser and 250 mJ per 1 microsecond pulse at 20 pulses per second for the excimer laser were used. Thermal gradients following laser application were measured. Excellent control of depth of tissue ablation was noted for both types of lasers. The tissue response was examined by light microscopy. Histological studies revealed tissue defects with clean contours. The coagulative necrosis zone for the 400 mJ holmium:YAG injuries measured from 370 microns to 640 microns, compared with 40 microns to 160 microns with the 250 mJ UV-excimer injuries. Wound healing was studied over a six-week period. Histologically, wound closure was completed after four weeks showing re-epithelialization without scar formation for both types of laser. The in-vivo tissue ablation characteristics and the operation reliability of the two lasers were compared.

Animals↗
PubMed1992

Infrared laser tissue ablation: holmium:YAG laser surgery.

The in vivo tissue ablation characteristics of a pulsed holmium:YAG laser (lambda = 1,980 nm) were studied. The laser energy was coupled onto nylon fibers 400 and 600 microns in core diameter. Laser incisions were made on white rats at different sites of the tongue and of the mucous membranes of the oral cavity. Power settings of 500 and 1,000 mJ/2.5-ms pulse at 5 pulses/s were used and the tissue responses examined by light microscopy. Wound healing was studied over a 6-week period. The results of this study are promising for future application of the holmium:YAG laser in otorhinolaryngology.

Animals↗
PubMed1992

[Atypical fractionation in advanced squamous-cell carcinomas of the head-neck area].

From May 1990 to May 1991, 23 patients with advanced, inoperable squamous cell cancers, clinically staged as III or IV, were treated by unconventional fractionation radiotherapy. Treatment consisted of a continuous hyperfractionated accelerated radiotherapy, delivering a total dose of 55.3 Gy within 17 consecutive days. In ten patients radiation therapy was combined with chemotherapy; 20 mg mitomycin C/m2, administered by intravenous bolus injection on day 5 of treatment. Apart from a confluent mucositis, treatment tolerance was good. Haematological toxicity from mitomycin C was minor and did not require any specific therapy. The mucosal reaction lasted six weeks (median duration) and was not thought to be increased by additional chemotherapy. In twelve of 23 patients a complete remission of the primary tumour was seen, in patients with lymph node metastases there was a complete response in 14 out of 20 patients. After a median follow-up of 18 months, ten of 23 patients have survived (8/23 without evidence of disease). Eleven patients have died due to local tumour progression and one patient died with distant metastases, being without evidence of local tumour. The advantage of this unconventional fractionation, which takes the described short potential tumour doubling time for head and neck cancers into account, is discussed.

Adult↗
PubMed1992

[Holmium:YAG laser surgery. Possibilities for use in inflammatory paranasal sinus diseases].

A pulsed Holmium: YAG laser (lambda = 2120 nm) was used during functional endoscopic endonasal surgery in ten patients with recurrent chronic inflammation of the paranasal sinuses. The Holmium: YAG laser energy was coupled to a 600 microns core diameter nylon fiber. Power settings of 950 mJ per 2.5 microseconds pulse at 5 pulses per second were used. Tissue responses to treatment were examined by light microscopy. The photoablative mechanism of the laser-tissue interaction led to bone and soft tissue ablation with only a minor thermal component in the target zone. In comparison with other laser types available clinically, there was no carbonization zone after use of the Holmium-YAG laser. The area of tissue damage produced was significantly smaller (370-520 microns only) and wound healing proceeded without complication. The physical settings of the laser equipment are described with regard to their significance in photoablation when using flexible light-conducting fibers. The possible role of the Holmium: YAG laser in clinical surgery is discussed on the basis of the present experience.

Adult↗
PubMed1991

Infrared laser stapedotomy.

A pulsed holmium: YAG laser (lambda = 1980 nm) was used to perform 0.4 mm stapedotomy fenestrations in human stapes footplates from freshly dissected cadavers under simulated surgical conditions. The energy was coupled into a 400 microns core diameter nylon fiber. Thermal gradients were then measured following laser applications and tissue responses examined by light microscopy. The results of this study suggest the feasibility of using a surgical holmium: YAG laser in middle ear surgery.

Humans↗
PubMed1989

[Schwannoma of the nose and paranasal sinuses].

A rare case of a Schwannoma (neurinoma) of the frontal sinus of a 75-year old male patient was examined clinically, histologically, and by electron microscopy. The fine structure of neurinomas occurs in two forms: Type Antoni A is composed of Schwann cells whose nuclei are arranged in palisading rows with greatly attenuated cytoplasmic processes extending from the Schwann cells in parallel alignment; Antoni B is characterized by loosely arranged Schwann cells set in meshwork of macrocysts and reticular fibers. It may be a degenerative form of Antoni A. In the present case Antoni A was the dominating pattern. A prominent basal lamina enveloping Schwann cells, as well as desmosome-like junctions between them, were identified. Furthermore, myelin figures, lysosomal bodies, intranuclear unmyelinated axons and concentric laminated inclusions, and annulate lamellae were found in Schwann cells. Luse bodies appeared in the tumour matrix. It is suggested that annulate lamellae may play a significant role in cell differentiation and tumour growth. No other ultrastructural signs of malignancy were seen.

Aged↗
PubMed1989

[Hyalinosis cutis et mucosae of the ear-nose-throat].

Hyalinosis cutis et mucosae (HCM) is a rare autosomal recessive disease of unknown aetiology and pathogenesis. In the skin and mucous membranes there is characteristically a deposition of hyaline-like material in the papillary dermis, around the small blood vessels and around skin appendages. Besides the manifold skin lesions, the mucous membranes affected are found in the nasal and oral cavities, pharynx and larynx. The latter causes the most characteristic symptom, namely, hoarseness, from birth. The lesions of the vessel walls are the most significant histopathological alterations. Ultrastructurally, massive deposits of amorphous, hyaline-like material in the dermis, reduction in number and size of the collagen fibrils and, finally, thickening of the basal laminae could be observed. The findings suggest an abnormal production of noncollagenous proteins as well as the alteration of the lysosomal systems of fibroblasts, endothelial cells and pericytes in the pathogenesis of hyalinosis.

Adult↗
PubMed1988

[Body plethysmography studies in patients with obstructed nasal respiration before and following corrective surgery of the nasal septum].

The nasal resistance of 28 patients with nasal septum deviation was measured before and after septum correction according to Cottle by means of body plethysmography. Clinical state according to clinical state history and body plethysmography results before and after surgery are compared by means of a standardised measuring unit. There was statistical significance for improvement of nasal ventilation after surgery in all three parameters. An analysis of the discrepancy between history, clinical state and rhinomanometry was made. History and rhinomanometry correlated closely. They seemed to be the most important parameters to determine nasal complaints. 30 volunteers with normal breathing function of the nose were examined. The normal resistance values of both nasal cavities are 0.31 kPa/l/sec. before and 0.28 kPa/l/sec after shrinkage of the nasal mucosa. The normal values of the nasal airflow of the entire nose were compared with the measurements of the patient group.

Adolescent↗
PubMed1986

[A method for puncturing the deep neck muscles in humans].

The authors developed a method to puncture neck muscles by means of computer tomographic control, enabling the introduction of an electrode into the obliquus capitis inferior muscle, to investigate the particular role of neck muscles in posture and head movement.

Electromyography↗
PubMedDate not supplied

Effects of the holmium:YAG and erbium:YAG lasers on endotracheal tubes.

Endotracheal tube (ET) fire is the most frequent complication arising with laser surgery in the upper aerodigestive tract. No data are available about the safety of commonly used ETs when used with recently developed high-energy pulsed lasers, working with only a minimal thermal component but mainly photoablative. A comparative in vitro study was performed with three types of endotracheal tubes to assess their resistance to wall and cuff damage by the laser beams of two pulsed infrared solid-state lasers. ET perforation was attempted with the erbium:YAG (lambda = 2,930 nm) and holmium:YAG (lambda = 2,120 nm) lasers. For all experiments, a repetition rate of 5 Hz was used. The 2.5-microseconds holmium:YAG pulses were coupled into a nylon fibre of 400 microns diameter. The 2.0-microseconds erbium:YAG laser pulses were applied to ETs through a lens system providing a spot size diameter of 200 microns. Polyvinyl chloride and silicon ET segments were exposed to laser pulse energies from 97 to 500 mJ in the presence of different anaesthetic gas mixtures. The time from the onset of exposure to tube perforation was recorded. Thermal gradients following laser application were measured. Laser exposure was continued for up to 90 s, unless tube ignition occurred. At all energy levels tested, the photo-ablative mechanism of laser-tube interaction, with few thermal components, led to laser-induced tube ignition if an FiO2 > 21% for the holmium:YAG and 34% for the erbium:YAG laser was established. With increasing pulse energies, ET segments ignited sooner. MLT tubes performed best in the present safety test.

Aluminum Silicates↗
PubMedDate not supplied

Does choir singing cause noise-induced hearing loss?

Although health problems in musicians have been previously reported; not much is known about noise-induced hearing loss due to choir singing. However, there are data to show that peak levels of more than 110 dB SPL are produced in choir singing, and major parts of sound energy can be found below 1 kHz and even 500 Hz but not below 100 Hz. To find out about possible hearing loss due to professional choir singing, we measured the hearing threshold level of 62 choir singers in a large opera choir. Most publications about noise-induced hearing loss report that the high-frequency region is impaired most. However, in our study the low frequency region was affected most, when compared with normative data (especially ISO 7029). Control groups of women and men with normal auditory function did not show pure-tone hearing thresholds different from ISO 7029. The permanent threshold shifts at 250 Hz and above are most likely noise induced with choir singing as noise source. However, hearing losses at 125 Hz and possibly partial at 250 Hz are caused by some other effect. An (unproven) hypothesis is that singing might lead to increased endolymph pressure, and thus might cause hearing loss especially in the low-frequency region. Whether more choirs show similar hearing impairment and whether singing raises cerebrospinal fluid pressure will be the subject of further investigations.

Adult↗