[Experimental evaluation of Vitaflon grafts in the venous position].

To examine the possibilities of replacing the great veins by Vitaflon grafts, an experimental study was made on 20 dogs. In the first group animals (n=10), a segment of the infrarenal posterior vena cava was replaced under conditions of routine blood flow. In the second group (n=10), an arteriovenous fistula closed after one month was formed on the thigh. The graft patency was checked by ascending phlebography. The observation period varied from 5 days to 11 months. After the animals were taken out of the experiment the grafts were inspected macro- and microscopically. It has been established that under conditions of routine blood flow all Vitaflon grafts were thrombosed for the first week. Acceleration of the flow provided for the patency of 10 grafts. The patent grafts took by means of formation of a connective tissue capsule on the exterior and formation of the neointima on their internal surface. The external capsule from the friable connective tissue emerged on the 2nd week of experiment; after 11 months it appeared as a thin layer of the solid fibrous connective tissue without evidence of inflammation which indicated the high biological inertness of the given type grafts. The neointima was formed from the parietal layer of fibrin organized in the direction from the area of anastomoses to the medium graft portion. No complete was recorded toward the end of experiment.

[The iliac vein occlusion]. / Narushenie prokhodimosti podvzdoshnykh ven.

Basing on roentgenological and morphological investigations the causes of the iliac veins passability disorder were studied up. In 45.1% of observations the stenosis was revealed of the left and in 1.2% of the right common iliac vein. Among the stenosis causes were osteal or cartilagenous prominences of vertebral column, intravascular structures (webs, membranes) in the left common iliac vein, the external iliac vein squeeze by internal iliac artery, retroperitoneal fibrosis, the right common iliac artery aneurysm, anomalous branching of parietal pelvic artery.

[Morphologic changes in the thrombus and venous wall in experimental phleobothrombosis and thrombophlebitis]. / Morfologicheskie izmeneniia v trombe i stenke veny pri éksperimental'nom flebotromboze i tromboflebite.

Phlebothrombosis and thrombophlebitis were induced in dogs by percutaneous intraoperative introduction of thrombotic mass, obtained in vivo (20-40 animal blood per 3-4 ml thrombin solution) into jugular vein and studied in postoperative days 1, 3, 5, 7, 10 and 14 through light microscope. The preparations were stained with hematoxylin and eosin and after Hart, Van-Gieson and MSB. Venous intima was established to alter already on the next day following thrombophlebitis modeling. On d 3 and 5 epithelium desquamation and moderate leukocytic infiltration of media between smooth myocytes were found. On d 7 signs of thrombus organization, i.e. invasion of fibroblastic series cells and small capillaries inside it, were demonstrated. Muscular layer and adventitia display leukocytic infiltration. Venous wall thickens due to disorders of blood passage in vasa vasorum. On d 10 the portion of the thrombus attached to the wall was essentially organized. Fibroblasts and capillaries invade inside the thrombus, connective tissue fibres are formed. Sclerotic changes were noted in adventitia. By the end of the 2nd week venous wall showed muscular layer atrophia and sclerosis. Middle portions of the thrombus were involved in organization, canals lined with endothelium are formed in it. In case of thrombophlebitis changes in thrombus and venous wall develop earlier and are more pronounced.

[The effect of preoperative radiotherapy using high-energy radiation on the pathomorphosis of kidney cancer]. / Vliianie predoperatsionnoi luchevoi terapii s ispol'zovaniem izlucheniia vysokikh énergii na patomorfoz raka pochki.

The paper analyses the effect produced by some preoperative treatments on the degree and depth of tumor cell lesion in 5 groups of patients with renal cell carcinoma. Group 1 consisted of 80 patients who had a surgical treatment alone and were studied for natural pathomorphism. Group 2 comprised 250 patients who had preoperative large-fractional radiation therapy in a total dose of 20 Gy. There was a partial suppression of mitotic and amitotic activities, more profound changes in organellae, particularly in mitochondria, nucleus, nucleolus, even destruction of individual cell elements as compared to the control group. Group 3 included 110 patients who had preoperative superfractional radiation therapy in a total dose of 14 Gy. The therapeutic pathomorphism of renal cell carcinoma was characterized by more profound and extensive changes in tumor cells as compared to Group 2. Group 4 involved 10 patients who underwent renal artery embolization. The letter led to the similar changes in tumor tissue as in Group 2. Particularly marked and extensive dystrophic and necrotic changes in tumor cells were observed in 35 patients who were enrolled into Group 5 and had preoperative renal artery embolization in combination with superfractional radiation therapy. The preoperative treatment techniques failed, however, to cause a total tumor parenchymal death as depending on the mode of preoperative therapy, the slightly damaged tumor cells were revealed in greater or lower quantities.