A solution to the problem of high-flow jets from miniature angiographic catheters

In this study we evaluated methods for reducing high-flow jets from 5-French catheters that occur when injection pressures approach catheter tolerance (1000 psi [6.9 MPa]). This "jet effect" has been responsible for subintimal extravasation of contrast material in patients. We designed a physical model that accurately measures flow rates through the end hole and each side hole of 5-French high-flow catheters under simulated physiologic arterial pressure. When a standard catheter commonly used for injection of contrast material was studied, flow of contrast material was 34% through the end hole and 31% through the distal side-hole pair at high injection pressures (1000 psi). We examined the effect of altering the size and configuration of catheter side holes and end hole in an effort to create an improved flow profile, and thus a safer angiographic catheter. End-hole flow rate was reduced by 73% to 9% of total flow by tapering the 5-French catheter to 0.018 in. (0.046 cm) and by using smaller 0.015-in. (0.038-cm) side holes for even flow distribution. The high-flow jets present with standard high-flow 5-French catheters do not occur when flow-restrictive end holes and side holes are used. A uniform flow profile can be obtained without sacrificing delivery of contrast material through small catheters.