Evaluation of a Percutaneously Controlled Hydraulic Occluder in a Rat Model of Gradual Venous Occlusion

Abstract

HOs may provide a method for gradual occlusion of congenital portosystemic shunts.

Methods of Gradual Vascular Occlusion and Their Applications in Treatment of Congenital Portosystemic Shunts in Dogs: A Review

“…Inflammation surrounding HOs was characterized as being consistently mild 72 . A gradual decrease in blood flow over an 8‐week period by HO inflation using a rat vena cava model has been reported 79 . To our knowledge, this is the 1st study to document a gradual decrease in venous blood flow after application of a surgical device.…”

Evaluation of manufacturing variability, diffusion of filling solutions, and long-term maintenance of occlusion in silicone hydraulic occluders

“…Procedures-Manufacturing variability was analyzed by comparing variation in internal luminal areas and filling volumes within each size group. Occluders were filled to 100% occlusion with air (n = 4), saline (0.9% NaCl) solution (4), or sodium hyaluronate (4) and submerged in simulated body fluid. Changes in luminal area and weight were recorded for 133 days to evaluate maintenance of occlusion.…”

“…Retrograde filling to remove air should be used when filling HOs with fluid. (Am J Vet Res 2006;67:1453-1458) ABBREVIATIONS HO Hydraulic occluder SH Sodium hyaluronate SBF Simulated body fluid attempt to explain variations in filling volume that were previously reported 4 in a rat model of gradual venous occlusion.…”

“…Saline solution was chosen because it has previously been evaluated 12 and because of its iso-osmolarity, ready availability, and low cost. Sodium hyaluronate, a high-molecular-weight, sterile, isotonic solution, was chosen on the basis of earlier experiences in our laboratory 4 and because of existing literature suggesting that high-molecular-weight fluids are less likely to diffuse through the silicone membrane of the HO. 10 Hydraulic occluders were prepared as described.…”

“…Injection ports were primed, and HOs were filled in a retrograde direction with a 22-gauge catheter to eliminate air. 4 The closed, noninflated HOs were placed on a flatbed scanner, e and digital images were obtained. The HOs were inflated with saline solution or SH through the injection port until complete occlusion of the visible lumen was observed, after which they were digitally scanned to confirm 100% occlusion and weighed to a precision of 10 -3 g on a laboratory scale.…”