Hydrophilic coatings diminish adhesion of glue to catheter: an in vitro simulation of NBCA embolization.

Abstract

PURPOSE: To determine whether new hydrophilic microcatheter coatings exhibit characteristics that diminish the chance of permanent endovascular glue adhesion during liquid acrylic embolization. METHODS: Common hydrophilic and nonhydrophilic microcatheters (both flow-directed and over-the-wire) used in neurointerventional procedures were evaluated in vitro for liquid acrylic (Histoacryl and Avacryl)-to-catheter bond strength, catheter endovascular friction, and catheter stretch (tensile strength). Sufficient test repetitions were acquired to achieve statistical significance. RESULTS: The bond strength between hydrophilically coated catheters and NBCA was significantly weaker than between nonhydrophilic catheters and NBCA. Hydrophilic catheter coating reduced dynamic endovascular friction by 30% to 35%. All flow-directed catheters exhibited considerably more stretch (less tensile strength) and therefore were more prone to fracture during withdrawal than over-the-wire systems. Histoacryl bonded to both hydrophilic and nonhydrophilic catheters with a significantly greater force than did Avacryl. CONCLUSION: Hydrophilically coated catheters should be less likely to exhibit permanent endovascular fixation during acrylic embolization because of a weaker catheter-NBCA bond and because of reduced catheter friction (allowing a larger portion of any applied catheter withdrawal force to be transmitted to the catheter tip with less force dissipated along the catheter resulting in stretch). A significant difference in NBCA types (Histoacryl and Avacryl) was discovered: Avacryl developed a significantly weaker bond with all catheter types.