Embolic substance

A survival advantage of an intra-arterial approach for inoperable pancreatic cancer patients was documented by Aigner et al. (1998) in a small randomized trial. In this study mitomycin, mitoxantrone and CDDP were used as standard intravenous treatment as well as in the experimental arm using an intra-arterial infusion. Here the cytostatics were mixed with amilomer which is a micro-embolizing substance. The survival advantage was 33 vs 11 weeks with significant improvement of performance status in the experimental arm. A problem of this study was the small number of treated patients. 

Tablets of medication intended for oral use contain inert filler materials such as talc (magnesium silicate), corn starch, cotton fibers, and other refractile and nonrefractile substances. Long-term drug abusers are known to prepare a suspension of medication for injection by dissolving the crushed tablet of cocaine, heroin, methylphenidate, or other narcotic in water. They then boil the solution and filter it through a crude cigarette or cotton filter before injecting the solution intravenously, subcutaneously, or intramuscularly. The talc particles eventually embolize to the retinal circulation and produce a characteristic form of retinopathy.

Retardation of clotting is important in blood transfusions, to avoid thrombosis after surgery or from other causes, to prevent recurrent thrombosis in phlebitis and pulmonary embolism. and to lessen the propagation of clots in the coronary aitcries. This retardation may be accomplished by agents that inactivate thrombin (heparin) or substances that prevent the fotmation of prothrombin in the liver (the coumarin derivatives and the phenylindanedione derivatives). 

Embolism A sudden partial or total blockage of a blood vessel caused by a blood clot, air, bacteria, foreign material, or other bodily substance. 

Aspects on the synthesis of polymers with a core-shell structure obtained from suspension polymerization, which is used in vascular embolization, are described elsewhere [3,12,13]. In this scenario the synthesis of polymer/inorganic hybrids has also been exemplified by our research group [14,15]. As a representative example of embolic agents, magnetic copolymers of poly(vinyl acetate) (PVAc)/poly(vinyl alcohol) (PVA) with a core-shell structure have high potential for the treatment of tumors and hyperthermia therapy of injured areas. The implementation of this process is possible by adhering superior control of the reaction system, which will produce particles of similar morphology comparable to the substance precursor. 

Embolization involves the deliberate occlusion of the arterial supply to the tumor to create ischemia, tumor necrosis, and to arrest growth by the intraarterial delivery of particulate materials, sclerosing solutions and substances introduced in a liquid state that eventually solidify or precipitate. This concept was first described in 1960 by Dawbain et al, who injected melted paraffin-petrolatum into an external carotid artery in a patient with head and neck cancer. It wasn t until the early 1970s that catheter technology improved to the degree for transcatheter embolotherapy to emerge. 

Technical aspects apply to both of these therapies, as known from classic transarterial (chemo-) embolization and percutaneous catheter-directed brachytherapy with microembolization using a local-acting substance to destroy tissues. 

Some silicones are used as medicaments. Dimethylpolysiloxanes of medium molecular weight (25000-40000) are suitable, alone or combined with other substances, as carminatives. Silicones may be applied in some diagnoses [615] and (as the foam) for some treatments of embolism [616],... 

For the inoperable case of FlCC, arterial injection or transcatheter arterial embolization (TAE) was invented (Pannuti, 1986 Doci, 1988). In this treatment, the hepatic artery entering HCC is occluded with an embohc substance, such as gelatin sponge particles, on the basis that HCC is pre-dominantly fed by the hepatic artery (Burgener, 1984). 

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