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J Rassweiler

Publications and source records attributed to J Rassweiler.

96 records · Page 6Linked to original sources
PubMed1981

Capillary embolization with Ethibloc: new embolization concept tested in dog kidneys.

Collateral vessels in tumors and arteriovenous malformations limit the effectiveness of therapeutic embolization. Capillary propagation of embolization media represents a possible solution of the problem. Embolization with Ethibloc (Hamburg-Norderstedt), a vegetable protein dissolved in alcohol, was performed in 15 renal arteries of dogs. Three embolized kidneys were completely resorbed, and four kidneys showed complete necrosis microscopically. Ethibloc in combination with 40% glucose guarantees homogenous embolization of the entire arterial bed including the capillaries. No complications were observed in other organs.

Animals↗
PubMed1980

[Capillary embolization. Part I: occlusion of the entire arterial system of the rat kidney (author's transl)].

Effect of tumor embolization is limited by parasitary blood supply. The influence of those collaterals should be decreased by transporting the embolization medium into the capillaries and tumor sinusoids. Controlled and safe capillary embolization is developed from studies of obtainable radiodensity, viscosity, and occlusion mechanism of Gelfoam-powder, IBC, and Ethibloc. The efficiency of these substances is compared to simple arterial ligation in experimental series with 400 Wistar rats. It is shown that ligation is comparable to insufficient capillary transport of the medium leaving islands of microscopically intact parenchyma. Easy application and total necrosis is guaranteed only by Ethibloc. Success of embolization is strictly volume dependent. Preinjected glucose is mandatory for homogenous distribution and peripheral transport.

Animals↗
PubMedDate not supplied

Lap simulator, animal studies, and the Laptent. Bridging the gap between open and laparoscopic surgery.

In an effort to ensure proper training and to establish a routine amongst the surgical team right from the start, we began practicing laparoscopic techniques with the lap simulator. After having acquainted ourselves with the fundamentals of this minimal-invasive method, we applied our newfound experience to the animal model. Even though the subsequent studies with pigs were the best learning model in which to practice different surgical techniques--e.g., ureter clipping and renal vessel triple stapling with the Endo-GIA--various problems can arise in a true clinical situation since anatomical diversity exists between an animal and human situs. We found that a compromise could be reached by simulating laparoscopic conditions during open surgery without endangering the safety of the patient during any point of the operation. After open surgical exposure of the Gerota fascia was carried out, the operative site was completely covered with the Laptent. From this moment on, all operative steps were performed with laparoscopic instruments under continuous video monitoring. Our step-by-step training program has exposed the surgeon and OR staff to the complexity of this new surgical technique. The use of the Laptent has successfully bridged the gap between open and laparoscopic surgery. Most important of all, those surgical centers without access to extensive experimental studies will realize that Laptent-assisted surgery can be of benefit and facilitate the clinical introduction of this minimal-invasive method.

Animals↗
PubMedDate not supplied

Experimental study of the effectiveness of capillary embolization using contrast-enhanced Ethibloc.

In experimental and clinical use, Ethibloc in combination with 40% glucose preinjection has proven to be of major advantage in tumor embolization. However, its low radiographic contrast is a limiting factor in monitoring its vascular distribution and venous propagation. Various contrast media were tested in order to enhance this contrast in laboratory and animal experiments. Normal rat kidneys (N = 96) and renal tumors, induced by Dimethylnitrosamine (N = 66) were tested as in previous studies. Ethibloc-N was produced by substituting Lipiodol for poppy seed oil which is an ingredient of the original Ethibloc. This proved to be the only embolization medium that combined the excellent properties of the original Ethibloc with increased contrast. All other embolization media tested resulted in new complications such as under-or overembolization and pulmonary embolism.

Animals↗
PubMedDate not supplied

Modulith SL20--development and clinical experience.

A third generation lithotripter was developed incorporating the advantages of high disintegrative efficacy, anaesthesia-free treatment, combined sonographic and fluoroscopic localization system as well as a multifunctional table for interdisciplinary use. The shock wave generator consists of a cylindrical-shaped electromagnetic coil with a paraboloid reflector. The waves are coupled by means of a water cushion and an impedance adapted foil in which the patient is comfortably positioned. Stones are localized by an in-line ultrasound probe or fluoroscopically by the integrated C-arm. Preclinical trials using the in-vitro stone model demonstrated the superior disintegrative capacity. The in-vivo animal studies evaluated the dose-dependent and reversible kidney trauma, which was comparable to that induced by other lithotripters. The clinical evaluation of the Modulith SL since 1988 was divided into three phases with different technical equipment. It was indicated that sonographic stone localization enables treatment of nearly all kidney stones and 12% of the ureteric calculi. As preference was given to in situ disintegration of all ureteral stones, X-ray targeting became necessary. By increasing the generator voltage in the third phase together with advanced experience, the disintegration rate (94%) was improved. The number of auxiliary measures after ESWL (11%) and treatment time (average 39 min) was decreased. Eighty-eight percent of our patients were stone-free at follow-up. The experience demonstrated that this lithotripter is also easy to handle for gallbladder stones and highly effective (82%) in treatment of endoscopically non-extractable bile duct stones.

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