Pattern of dispersion from a pulse-spray catheter for delivery of thrombolytic agents: Design, theory, and results

Rationale and Objectives. The purpose of the study was to qualitatively compare the fluid dispersion characteristics of a commercially available side-slit pulsespray (PS) catheter with those of a conventional sidehole catheter. Methods. The dispersion pattern from a 5-F catheter for PS thrombolysis was evaluated in gelatin models and in human thrombi in vivo and was compared with that from a 5-F side-hole catheter. For in vitro experiments, catheters were placed in gel and pulsed with 0.2 mL of dyed water by hand or continuously infused at a rate of 30 or 60 mL/h with an infusion pump. For clinical studies, a single 0.2-mL pulse of contrast medium was injected before lysis and examined with digital subtraction angiography. Results. Fluid was distributed evenly from the PS catheter in both gel and thrombi, despite placement of some slits in media with variable viscosity. The side-hole catheter produced a heterogeneous dispersal pattern, and most fluid exited through side holes in areas where outside resistance was lowest. Conclusion. The PS catheter provides more even fluid distribution than the side-hole catheter.