Zeitschrift fur experimentelle Chirurgie最新文献

The effects of ultrasonic saw cuts in the epiphyseal cartilage reach were investigated experimentally in dogs. Saw cuts across led to an impaired growth, whereas longitudinal cuts caused a stimulation of growth. The dimensions of the growth influence were, however, very different and not calculable. Further on, the temporal lapse of the bony repair was investigated radiologically comparatively after osteotomy by the ultrasonic saw or by the oscillated saw. The bony repair took place more slowly after ultrasonic osteotomy generally speaking. The indications and limits for the application of the ultrasonic bone saw were deduced from the investigation results by including the bibliography.

A novel modification of a two-row intestinal anastomosis technique is introduced. A step-like anastomosis was carried out by a short stepwise resection of the several intestinal wall laminae with intramural adaptation on the specific juncture. In 44 end-to-end intestinal anastomoses in dogs and 5 in children there were not observed any insufficiency and stenosis.

The investigations were carried out in rats by means of the amino acid 15N-glycinee 6 to 12 weeks after the gastrectomy. 10 rats were operated by Graham and 9 by Longmire, Gütgemann. 12 rats as a control group were not operated. The animals got a single dose 15N-glycin with the food in the beginning of the experiment. The excretion of the isotope was measured every twelve hours for 5 days. All rats had a positive nitrogen balance. The rats operated by Graham excreted with the urine significantly less 15N than the rats of the other two groups. These differences were caused by different fast adsorption of the amino acids likely, at this the rats operated by Graham absorbed retardingly evident qualified by the absent duodenal passage. These disturbances of the amino acid absorption are not aggravating, because the nitrogen balance and the protein synthesis rate of the animals were normal.

By operative reduction of the renal tissue on 1/5 of both kidneys there are to be produced a chronic renal insufficiency in 21 black mini-pigs. The operative procedure was carried out at one time (nephrectomy and resection of the residual kidney) or at two times (in one group of it at first the nephrectomy and in the other group at first the resection of the kidney). Only 50% of the animals died with the symptom uremia in renal insufficiency. The nephrectomy--with a temporarily shifted resection of the residual kidney--effects the desired changes most approximately with very different reaction. This procedure appears as an animal model for the chronic renal insufficiency altogether not suitable.

Chemical and structural surface changes at enosseous bioglass-ceramic-implants (Ap 40) were investigated by means of electron microprobe after an implantation period of 4 to 52 weeks. An intimate bonding between regenerated bone and bioglass-ceramic surface was evident at points already after 4 weeks. Initial degradation processes at implant surface came to a standstill after 12th week. A calcium and phosphorus rich layer of great importance for implant stability and biocompatibility was formed immediately contacting the bone. This surface layer had a thickness of nearly 25 micrometers -- 30 micrometers at 12 weeks and remains unchanged up to 52 weeks. The registered calcium and phosphorus impulse rate (cps) is equal to that of neighbouring bone. Chemical similarity of implant surface makes bioglass-ceramic Ap 40 a suitable biomaterial for durable bone replacement.

The thrombosis in dependence on the stream velocity in the electrically induced thrombosis was investigated by blood flow measurements in the femoral artery in 16 mongrel dogs. Thromboses were shown histologically in all 16 animals. 8 of them did not obturate. Obturating thromboses were produced with the application of anodic direct current of 1 mA during 60 minutes only with a blood stream velocity between 0.0465 and 0.0928 m/s. Not any obturating thrombosis was visible outside of this range.

The premature manifestation of the arteriosclerosis in the adductor canal makes this vascular region to a first-class site of predilection. These localised mechanical morphological factors were malingered by means of polyvinylchloride splinting in animal experiment. All degrees of severity of the arteriosclerotic vascular wall changes were shown histologically. The changes of the arteries were developed essentially slighter under medication of pyridinolcarbamat, however, they could not be prevented.

A totally artificial heart--the Rostock totally artificial heart (Rostock TAH) was implanted in calves. We can give the following deductions after 27 examinations: -- The Rostock TAH was tested successfully in endurance test about 7 months; it show no sign of wear. -- The surgical technique of the implantation was standardised and a successful experimentation is possible. -- The longest survival time was 15 days. The hemodynamic early results were very good in 3 other animals. -- Modifications of the Rostock TAH were taken up relating to the dimensions of the artificial ventriculi and by mounting a screw cap for avoiding an air embolism. -- Adaption tests in the corpse show that the present form of the artificial heart is not ideal for a possible application in man. -- The problem is still existing in developing a suitable drive system locates intrathoracically. The present drive and control system on a pneumatic base is qualified only for the animal experiment but not for a possible application in man.