Biomedical subjects

E Wintermantel

Publications and source records attributed to E Wintermantel.

42 records · Page 3Linked to original sources

PubMed1982

The thermic vascular anastomosis (TVA). III. Analysis by histology.

In 48 Sprague Dawley Wistar rats Thermic Vascular Anastomoses were analyzed by histology 1, 10, and 30 days, 6 and 18 months postoperatively. Fibrin glue turned out to be a valuable additional fixative, effective in preventing ruptures of the anastomoses. It did not modify the formation of a pseudo-intimal layer of connective tissue between the original vascular ends. The healing process of TVAs is worked out; references to earlier studies describing microvascular procedures with fibrin glue application are made.

Animals↗

PubMed1981

The thermic vascular anastomosis (TVA). A new nonsuture method. I. History, instruments, and microsurgical technique.

In order to unite blood vessels in a split second during a total clamping time of less than three minutes a new microsurgical technique has been developed. Heat from a frequency electric current applied to calibrated metal loops unites the cuffs of the vessel ends instead of sutures. As a model for vascular anastomoses the new technique was used in an experiment with 320 rats. Two energy output adjustments of the power source combined with application of fibrin glue on the anastomosis are compared. The new instruments developed for this technique and the operation method are presented with reference to earlier vascular surgical procedures, and the results of patency controls of the anastomoses one day, 10 days, and 30 days postoperatively are listed. Preliminary findings of a long term study are added. This study shows that fully patent anastomoses can be obtained with this technique in much less time than with suturing.

Angiography↗

PubMed1981

[Carbohydrate metabolism in brain and liver tissue following experimental vascular suturing of the right carotid artery (author's transl)].

Experiments with Wistar rats have been performed in order to analyse brain and liver metabolism after suturing of the rats right carotid artery. It should be figured out how much an interruption of the bilateral blood supply of the brain during end-to-end-anastomosis of a carotid artery would interfere with normal brain and liver metabolism. General anaesthesia of all animals was obtained with pentobarbital. The vascular anastomoses have been performed by using the microsurgical technique. Groups of animals were formed in order to analyse metabolism after various periods of postoperative survival. Brain and liver tissue was removed and the metabolism stopped immediately by freezing the tissue in liquid nitrogen. Biochemical analysis showed several highly significant changes of levels of values indicating hypoxia. Additional experiments have been carried out in order to find out whether hypoxia could be detected in other organs of the body such as the liver after performing the same microsurgical procedure on a carotid artery and how pronounced these changes would be compared to those of brain metabolism. Results of experiments performed up to now indicate that hypoxia also develops in liver tissue.

Animals↗

PubMed1980

Microvascular auscultation. A new technique, using a diplo-microphone, for analysis of blood flow at suture lines in small arteries.

A new atraumatic method for patency and blood flow control of microvascular anastomoses has been developed. Sounds proximal and distal to a suture line are separately detected by means of two specially modified miniature microphones built together as an auscultation unit and named a diplo-microphone. Transmission of the two amplified signals to a loudspeaker as well as to an oscilloscope screen allows analysis of patency at the anastomosis. Photos taken of the sound waves are individual records characterizing blood flow on both sides of the suture line. The new method has been tested in carotid arteries of Wistar rats. Sounds at stenoses and end-to-end anastomoses have been detected, and several characteristics of postoperative sound waves have been worked out. The new method has turned out to be more sensitive in detecting medium-sized stenoses than radical pressure tests performed with forceps. Construction and application of a diplo-microphone are described. Auscultation results of normal and stenosed arteries are discussed.

Amplifiers, Electronic↗

PubMed1979

A new gearing approximator for microsurgical vascular anastomoses.

A new gearing approximator for microsurgical vascular anastomoses is described. A highly precise and smoothly working robust gearing in connection with an asymmetrically notched key allows quick application of the approximator and an exactly adjustable interclip distance. By means of a combined handling and gearing screw and exchangeable 30 degrees-angled clips the instrument can easily be applied in narrow operating fields, and it can be handled under vision through the operating microscope without change in magnification adjustment. A quickly increasing platelt aggregation at the suture line and an early "slow flow" can be achieved by gradual opening of the clips. The ease of approximator application may contribute to shortening operation times.

Neurosurgery↗

PubMedDate not supplied

Angiopolarity: a new design parameter for cell transplantation devices and its application to degradable systems.

The purpose of this study was to obtain directional angiogenesis of small blood vessels and capillaries to an implant made from a resorbable polymer for hepatocyte transplantation. It was intended to mimic the native acinar structure of the liver in form to facilitate replication of the cells and organ growth. The implant device structure was designed for injection to minimize surgical trauma. Hollow microspheres with an open porous wall structure and one large central opening were made from poly(d,1-lactic-co-glycolic acid) (85:15 lactic:glycolic). This polymeric scaffold was seeded with hepatocytes and implanted into the abdominal wall muscle of syngeneic Fisher rats. Specimens explanted up to 56 days postoperatively showed hepatocyte survival and the development of a directional blood supply, a phenomenon known as "angiopolarity." This study should help in addressing the issue as to whether vascular cell implants with posttransplantation organ growth should be attempted.

Animals↗