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Biomedical subjects

O Voronkova

Publications and source records attributed to O Voronkova.

7 recordsLinked to original sources
PubMed1996

Poly (2-hydroxyethyl methacrylate) particles for management of hemorrhage of complicated origin: treatment of hemobilia.

Poly (2-hydroxyethyl methacrylate) (PHEMA) particles of cylindrical and spherical shape were developed as a preparation for tumor treatment or control of hemorrhage by blocking their blood supply. In this report, PHEMA particles were used for the management of hemobilia, that is, bleeding into biliary passages. The origin of hemobilia in 31 patients was localized by selective angiography. With the objective of prophylaxy of hemorrhage, selective embolization with PHEMA particles of the branches of the hepatic artery responsible for the supply of blood to the focus of damage was used in 18 patients. This low-trauma method allowed either a complete control of bleeding or, at least, intraoperative blood loss was reduced more than twice. Histological investigation of the occluded blood vessels showed that the thrombus was attached to the particles and was reinforced by the porous structure of the polymer. A hypercoagulation reaction was observed in the postembolization period. This allowed correction of the hypocoagulation in the hemostasis system.

Bile Ducts, Intrahepatic↗
PubMed1992

Hydrogels in endovascular embolization. V. Antitumour agent methotrexate-containing p(HEMA).

The aminohexyl derivative of the copolymer of 2-hydroxyethyl methacrylate and ethylene dimethacrylate (p(HEMA)-Hex) in the form of regular spherical particles was used as a polymeric carrier for chemically sorbed methotrexate (MTX). The effect of the washed p(HEMA)-Hex-MTX carrier on the morphological structure of donor blood, on blood coagulation indicators and on responses of the living tissue surrounding the material which has been in the blood vessel of the rabbit for various periods of time was evaluated. MTX is capable of diffusion for several days from the embolic material.

Animals↗
PubMed1992

Haemostatic activity of ethamsylate and aminocaproic acid adsorbed poly(2-hydroxyethyl methacrylate) particles.

A haemostatic material suitable for embolization was prepared by the adsorption of haemostatics--ethamsylate and aminocaproic acid in the spherical particles of porous poly(2-hydroxyethyl methacrylate) (p(HEMA)). The degree of purification of ethamsylate-treated particles was tested by an analysis of donor blood in contact with the material. An evaluation of the haemostatic properties of these materials was obtained by the determination of the indicators of blood clotting: activated partial thromboplastin time, thrombin time, and prothrombin time. Ethamsylate or aminocaproic acid-containing p(HEMA) has a distinct haemostatic effect on pathological blood of patients suffering from focal alterations of the liver. These haemostatic emboli materials show promise for the immediate control of various haemorrhages; when introduced into a zone with increased haemorrhage, they may help to correct disturbed haemostasis.

Adsorption↗
PubMed1992

Use of poly(2-hydroxyethyl methacrylate) for endovascular occlusion in pediatric surgery.

Embolization using poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel particles, of cylindrical spherical form, was successfully achieved in 42 children treated for non-operable haemangiomas of the liver, and angiodysplasias. Spherical PHEMA hydrogels appeared to be the only possibility for the treatment of 26 children suffering from extensive cavernous haemangiomas of face and neck. Particles were able to cover the tumour, stop its growth and allow the use of local hyperthermia with the electromagnetic field. A partial two-stage embolization using beaded PHEMA was also used as part of the multistage treatment for curing the spleen in 28 children suffering from haemolytic spherocytic anaemia, thrombocytopenic purpura and portal hypertension.

Adolescent↗
PubMed1990

Poly(2-hydroxyethyl methacrylate) beads for the preoperative endovascular occlusion of branches of the hepatic artery in focal alterations of the liver.

Spherical particles of porous poly(2-hydroxyethyl methacrylate) have been used in the treatment of patients suffering from focal alterations of the liver, namely haemangioma and hypervascular tumour. The treatment consisted of the preoperative endovascular occlusion of branches of the hepatic artery using these spherical particles, and was followed by an operation. The main merit of the preoperative occlusion of blood vessels is that it substantially reduces blood loss during surgery. In order to determine the optimal time for the operation on the liver, indicators of the coagulation system were examined in successive terms of the postemboilization period. Reaction of the organism to endovascular occlusion is reflected in hypercoagulation changes in the coagulation system.

Blood Loss, Surgical↗
PubMed1988

Hydrogels in endovascular embolization. IV. Effect of radiopaque spherical particles on the living tissue.

In this study we report the results of toxicological, histological and haematological experiments on radiopaque spherical particles based on poly(2-hydroxyethyl methacrylate). These particles have been developed for endovascular occlusion of various organs. Radiopacity was attained by two independent methods: the chemical attachment of radiopaque substances to the hydrogel or the precipitation of radiopaque substances in the hydrogel network. The first method yields particles that appear to have uniformly-distributed contrast material, but in the particles prepared by the second procedure the contrast material is predominantly located on the surface. The visibility of such particles by X-rays makes possible controlled embolus introduction and inspection of the polymer for long periods after embolization. Radiopaque contrasting changes the morphology and reduces the porosity of the material but supports quick thrombus formation. Embolic material implanted in rabbits becomes surrounded by a thin fibrous capsule and undergoes partial organization. This and other results of medico-biological investigations have fully demonstrated the biocompatibility of radiopaque spherical emboli, which can now be used clinically.

Animals↗