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H D Reidenbach

Publications and source records attributed to H D Reidenbach.

At least 19 recordsLinked to original sources
PubMed1992

Technological fundamentals of endoscopic haemostasis.

In order to perform endoscopic haemostasis there exist several different mechanical, biochemical and thermal methods, which may be applied together with rigid or fully flexible endoscopes in different situations. The technological fundamentals of convective, conductive and radiative heat transfer, the irradiation with coherent electromagnetic waves like microwaves and laser radiation and the resistive heating by RF-current are described. A review of the state of the art of haemostatic coagulation by laser radiation (photocoagulation) and radio-frequency currents (surgical diathermy, high-frequency coagulation) is given. The wavelength-dependent interactions of coherent light waves are compared especially for the three mainly different laser types, i.e., carbon-dioxide-, neodymium-YAG- and argon-ion-laser. The well-known disadvantages of the conventional RF-coagulation are overcome by the so-called electrohydrothermosation (EHT), i.e. the liquid-assisted application of resistive heating of biological tissues to perform haemostasis. Different technological solutions for bipolar RF-coagulation probes including ball-tips and forceps are shown and the first experimental results are discussed in comparison.

Cerebral Hemorrhage↗
PubMed1992

An electrohydrothermosation system for application in endolaryngeal and enoral surgery: a technical report.

The use of medical lasers or high-frequency (HF) devices ('electrocautery') allows the dissection of tissue by an application of heat. The main advantage of such techniques is the reduction of intra-operative bleeding. On the other hand, carbonization and coagulation lead to difficulties in the histological investigation of the resected specimen. Electrohydrothermosation (EHT) systems are irrigation-supported HF devices. The cutting or coagulation electrodes are continuously rinsed with distilled water in order to minimize thermal interactions with the tissue. We developed an EHT system for endoscopic head and neck surgery. The system was used to remove defined specimens from pig larynges and tongues experimentally. We compared the results with those obtained by a surgical CO2 laser and found that carbonization and overall tissue damage were less severe with EHT than with laser surgery. This leads to the conclusion that EHT is an improvement of conventional HF surgery and may be an alternative to laser surgery in the head and neck.

Animals↗
PubMed1989

A comparative study of the tissue-destroying effect of the laser and electrocoagulation.

The effect of the laser on compact, glandular tissue at the dosage employed for the local palliative treatment of tumors, can largely be mimicked with the aid of high-frequency current (HF-current), applied with the aid of an electro-hydro-thermo-probe: The experiments described in the present study were performed on the livers of 70 male Wistar rats. The laser was applied for 2 seconds at an output of 80 J at a distance to the tissue of 0.5 cm. In the first stage, in the acute experiment, the effect of the HF-current was matched to that of the laser by varying the modulated and unmodulated current components. It was found that the depths of penetration into the tissue at the given laser settings could be achieved with modulated HF-current (so-called coagulation current) at an output of more than 72 watts (equipment setting K 10) coagulation being performed for 10 seconds. The admixture of modulated HF-current (so-called cutting current) reduces the depth of penetration into the tissue. In the first 5 days, the depth of penetration increases after both laser irradiation and HF-coagulation, by a factor of 2 to 3. With respect to the depths of penetration (DP), the scatter ranges, and the histological changes, no difference is to be seen between laser and HF lesions: Laser DP = 5.7 mm (confidence range: 4.4-7.0 mm); HF DP (equipment setting K 10) = 4.8 mm (confidence range: 3.6-5.4 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1980

The healing process of experimentally produced bleeding lesions after hemostatic electrocoagulation with simultaneous instillation of water.

Fifty experimentally induced, standardized gastric bleeding lesions were successfully arrested in the dog using electrocoagulation with simultaneous instillation of water (EHT-coagulation). The contact pressure of the coagulating electrode was kept almost constant by means of a spring mechanism. The coagulated lesions healed without secondary enlargement of the coagulation effect and without complication. No secondary perforations were observed. Even when coagulation was carried out at an output power about 30% higher than the mimimum power necessary for reliable hemostatic coagulation, no complications were observed. Only with additional post bleeding arrest coagulation in excess of 10 seconds at this higher output, were two primary performations produced in 2 out of 12 cases. The non-perforated remaining 10 lesions healed without complication. With additional coagulation (at power output setting 6 for 20 seconds - 8 cases; at power setting 7 for 10 seconds - 6 cases), no perforations were observed and healing was without complications. Thus, in animal experiments, the therapeutic range for the arrest of bleeding using the electro-hydro-thermo-electrode is adequately large. The technique should be tested in clinical trials.

Animals↗
PubMed1979

Modified electrocoagulation and its possibilities in the control of gastrointestinal bleeding.

In acute experiments in the stomach of dogs electrocoagulation with simultaneous instillation of water (EHT-electrode i.e. electro-hydro-thermo-electrode) proved the most effective electrocoagulation method for controlling standardized bleeding: Optimal visibility at the bleeding site, extension of the therapeutic range as well as the avoidance of charring at the bleeding site are its major advantages. Disturbing adhesion of coagulated material on the electrode is also avoided. The electro-hydro-thermo-electrode is a cheap and portable means of controlling bleeding.

Animals↗
PubMed1976

[Clinical results of laser-coagulation in gastro-intestinal bleeding (author's transl)].

Endoscopic laser-coagulation was used 94 times in 14 patients to stop gastro-intestinal bleeding or coagulate potential bleeding sources during non-bleeding intervals. Lasting haemostasis was achieved in three cases of incomplete gastric erosion, one of gastric ulcer, one of duodenal ulcer and one of bleeding after antral rugectomy. It failed to stop severe arterial bleeding in a case of gastric carcinoma. Lasting haemostasis was achieved in six haemangiomas of the colon, one case of angiomatosis of the antrum with 62 individual sites, two of angiodysplasia of the colon, 17 lesions in Osler's disease of the oesophagus (2 cases), stomach (10) and duodenum (5). The procedure was performed in the course of diagnostic endoscopy with an argonion laser developed by the authors, which has a density of 0.7-1.3 W/mm2. No complications have been observed so far.

Argon↗