A quantitative method for determining angiographic jet energy forces and their dissipation: Theoretic and practical implications

Abstract

Jets emanating from the exit holes of cardiac catheters during angiographic injections are theoretically capable of producing severe localized cardiovascular trauma. We adopted a fluid mechanical model of an axially symmetric jet to define these energy forces quantitatively, especially as they would occur in the clinical setting. During angiographic injection at all catheter flow rates used clinically, the jet emanating from the exit hole was always turbulent. The physical characteristics of the turbulent jet penetration into the intravascular blood fell upon a universal curve independent of the jet Reynolds number. This curve, never previously described, allows ready calculation of hydraulic energy dissipation for any catheter of known length and lumen size. The diameter of the catheter exit orifice has a greater effect than injection flow rate on decreasing jet penetration. These results provide useful guidelines for reducing trauma during routine angiography.

The mixability of angiographic contrast with arterial blood

“…Therefore, it is possible to identify in this modeling process both the jet intact core penetration length and the mixing zone which when combined yield the total mixing length for the injection. A theoretical approximation on discharge of free jets into stationary unbounded fluids 23 suggests that the jet energy begins to decay after seven exit-hole diameters. For catheter inner diameters about 30%-40% of the arterial diameter, this value corresponds to two or three arterial diameters which are similar to our values for the jet intact core penetration distance.…”

Interventional Radiology Suite: A Primer for Trainees

“…This effect refers to the pressure that pushes back on the catheter when injecting fluid through the tip of the catheter. This pressure can not only dislodge the catheter from the ostium of a vessel, it can also traumatize a vessel [8]. Whereas in flush catheters the side holes are designed to allow for large infusion volumes, in selective catheters, the side holes function to disperse the end-hole jet effects [3].…”