Hemodialysis catheter integrity during mechanical power injection of iodinated contrast medium for computed tomography angiography.

Abstract

CT angiography (CTA) requires vascular access with flow rates of 5-7mL/s. Hemodialysis (HD) is performed at 6-10mL/s. The purpose of our study is to evaluate the structural integrity of HD catheters in the administration of contrast media via a mechanical power injector under varying conditions. Four HD catheters were evaluated in an in vitro study. Tested were contrast media type (iopamidol 300 and 370 mgI/mL), temperature (25 and 37 °C), catheter diameter (14 Fr to 16 Fr all with double-lumen capacity), catheter length (19-32cm), and simultaneous double-lumen or single-lumen injection within each of the catheters. Peak plateau pressures (psi) were recorded with flow rates from 5 to 20mL/s in 5mL/s increments. In total, 864 unique injections were performed. No catheter failure (bulging/rupture) was observed in 864 injections. Maximum pressure for single-lumen injection was 51.7 psi (double-lumen: 26.3 psi). Peak pressures were significantly lower in simultaneous double-lumen vs. single-lumen injections (p < 0.001) and low vs. high viscosity contrast media (p < 0.001). Neither larger vs. smaller diameter lumens (p = 0.221) nor single-lumen injection in arterial vs. venous (p = 0.834) were significantly different. HD catheters can be used to safely administer iodinated contrast media via mechanical power injection in in vitro operating conditions. Maximum peak pressure is below the manufacturer's 30 psi limit at flow rates up to 20mL/s in double-lumen injections and up to 10mL/s in single-lumen injections, which is higher than the usual maximum of 8mL/s for CT angiography in clinical settings.