Introduction: The Onyx Embolization System (ev3) utilizes dimethyl sulfoxide (DMSO) as a solvent for ethyl vinyl alcohol. DMSO is a highly polar organic solvent known to break down organic and inorganic compounds, which may dissolve catheters that aren’t specifically designed or approved for DMSO compatibility. Situations may occur when a physician wishes to use Onyx via a non-approved catheter. We sought to determine the compatibility of DMSO with various microcatheters.
Methods: A total of 45 catheters (3x15 models from 7 manufacturers) were tested. A solution of 1% methylene blue in DMSO was then flushed though each of the catheters and the distal ends were occluded with hemostats. The proximal end of each catheter was occluded with a stopcock. The catheters were placed in a saline solution at 38oC and then checked for leaks by applying 200 lbs/in2 of pressure via an endoflater at 10 minutes, 1 hour, and 24 hours.
Results: One each of the Rebar-10 (ev3) and the Prowler Select Plus (Cordis) catheters suffered fractures in the catheter near the distal hemostat occlusion site. The DAC 038 (Concentric Medical) catheters could not be occluded distally due to their reinforced lumen. One of the Merci Microcatheters (Concentric Medical) and one of the Echelon-14 catheters (ev3) leaked at the hub. One of the Reperfusion Catheters (Penumbra) leaked from approximately midway down the catheter. The remaining catheters had no leaks at any point.
Conclusions: Of 42 successfully tested catheters, one developed a clinically significant leak, which occurred along the distal aspect of the catheter within 10 minutes. Four other catheter leaks were likely caused by traumatic fractures from the hemostats (2) or occurred at the hub (2). Most catheters appear to tolerate DMSO thus allowing Onyx as a consideration in an emergency.
Patient Care: This will improve patient care by providing physicians with greater knowledge of the use of off-label endovascular catheters with dimethyl sulfoxide in the course of endovascular therapy.
Learning Objectives: By the conclusion of this session, participants should be able to understand to limitations and potential applications of the use of dimethyl sulfoxide in off-label endovascular catheters.