Vessel Wall Reaction Research Articles

Chronic vascular reactions to steel coil occlusion devices.

Original Gianturco steel coil vascular embolization devices and two modifications were compared for their occlusive effects and for the degree of adverse reaction in the surrounding vessel wall. Modifications consisted of silk or Ivalon replacing the wool strands of the original device. Single coils were placed into the left renal artery of nine mixed breed swine and restudied 3 months later. The bare coils did not occlude the vessels nor lead to significant foreign body reaction. Wool, silk, and Ivalon coils produced prompt and sustained renal artery occlusion. Upon histologic examination of the vessel wall, foreign body and chronic inflammatory reaction was found to be strongest against wool. This reaction was less with silk and markedly diminished with Ivalon. The results indicate that silk and Ivalon coils, while having the same occlusive effect, are preferable to wool coils if less local reaction is desired.

The platelet as an inflammatory cell.

The primary hemostatic response involving the platelet-blood vessel wall reaction in mammals resembles, to a significant extent, the basic cellular defense mechanisms of more primitive forms such as invertebrates. Mammalian primary hemostasis appears to have retained a phylogenetic vestige of primitive leukocyte behavior (Salt, 1970). In this evolutionary sense, the platelet might be thought of as a special form of leukocyte. Human platelets contain intracellular granules similar to the classic lysosomes of polymorphonuclear leukocytes (Marcus et al., 1966) and contribute to the inflammatory response accompanying tissue injury by releasing constituents which may alter blood vessel reactivity. Platelets have long been known to contain vasoactive amines which are released upon aggregation. Platelets interact with many types of particulate matter including bacteria and viruses and immune complexes which lead to the release of intracellular constituents, including serotonin (Mustard and Packham, 1970), prostaglandins (Smith and Wallis, 1971), cationic proteins (Packham et al., 1966), and various proteolytic enzymes such as cathepsin A (Nachman and Ferris, 1968), elastase (Robert et al., 1970), and collagenase (Chesney et al., 1974).