Effect of Petrolatum Coating on the Rate of Occlusion of Ameroid Constrictors in the Peritoneal Cavity

Abstract

The lack of closure of AC supports the conclusion that vascular attenuation is not dependent on luminal constriction alone. Petrolatum coating did not slow the rate of casein expansion and is unlikely to be clinically useful.

Evaluation of the Characteristics of Venous Occlusion After Placement of an Ameroid Constrictor in Dogs

“…Expansion of ameroid does not completely obliterate the lumen of the AC 16,17,19,20 and it has been hypothesized that the complete vascular occlusion observed after placement of the AC on a PSS may be the result of both physical expansion and an inflammatory response to the ameroid 19–21 . This hypothesis agrees with microscopic and gross observations of arteries encased in ameroid 15 leading to the conclusion that occlusion probably resulted from 3 mechanisms: (1) reduction in external vessel diameter because of luminal swelling of the ameroid, (2) fibroblastic response of the arterial walls at the site of application, and (3) formation of intra‐luminal thrombi arising concentrically from the intima.…”

“…Most reports evaluating the AC for treatment of PSS in small animals assume that vascular occlusion occurs from physical expansion of the AC 11,12,23–25 . Recent experimental studies suggest, however, that physical expansion plays only a minor role 19,21 . Adin et al 19 reported that after implantation of AC in the peritoneal cavity of rats, luminal area decreased only 32% by 6 weeks.…”

“…Recent experimental studies suggest, however, that physical expansion plays only a minor role 19,21 . Adin et al 19 reported that after implantation of AC in the peritoneal cavity of rats, luminal area decreased only 32% by 6 weeks. It was speculated that the minimal luminal constriction would not explain venous occlusion seen with the AC, and that inflammation and fibrosis were likely the more important factors contributing to occlusion.…”

Correlation of Ischemic Area and Coronary Flow With Ameroid Size in a Porcine Model

“…Hughes and colleagues [1] reported that ameroid constrictors also cause mechanical trauma, which may lead to endothelial damage, platelet aggregation, and thrombus formation and may induce a foreign-body reaction with local scar formation. Adin and coworkers [14] suggested that along with hygroscopic expansion of the constrictor, implant-related inflammation and fibrosis are the major contributors to vascular occlusion. These findings implied that it might be possible to achieve ameroid-induced vascular occlusion regardless of whether the coronary artery size and ameroid size were strictly matched.…”

In vitro development and evaluation of a polyacrylic acid–silicone device intended for gradual occlusion of portosystemic shunts in dogs and cats

“…[6][7][8]26 The weight of an ameroid ring constrictor (approx 1,400 mg 27 ) has the potential to cause shunt closure by vessel kinking, which may lead to portal hypertension. [6][7][8]26 The weight of an ameroid ring constrictor (approx 1,400 mg 27 ) has the potential to cause shunt closure by vessel kinking, which may lead to portal hypertension.…”