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

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.