Influence of Ultrasound Microbubbles on kidney oxygen tension
Issue title: Selected papers of the 36th Conference of the German Society for Clinical Microcirculation and Hemorheology, 5–8. June, 2017, Greifswald, Germany
Guest editors: M. Jünger, A. Krüger-Genge and F. Jung
Affiliations: [a]
Institute of Biomaterial Science and Berlin-Brandenburg Centre for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany
| [b] Department of Plastic and Hand Surgery, University Hospital Regensburg, Germany
| [c] Department of Biomaterials, Central Institute for Biomedical Engineering, University of Ulm, Ulm, Germany
| [d] Department of Radiology, University Hospital Regensburg, Regensburg, Germany
Correspondence:
[*]
Corresponding author: Prof. Dr. L. Prantl, Department of Plastic and Hand Surgery, University Hospital Regensburg, Germany. E-mail: lukas.prantl@klinik.uni-regensburg.de.
Abstract: Ultrasound contrast agents (USCA) allows the dynamic detection of blood flow of both the macro and microvasculature. An obvious prerequisite for USCAs is the unhindered passage of clinically relevant dose levels through the microcirculation especially of the lungue, where they have to pass capillaries with diameters of around 4 μm. While smaller microbubbles rapidly passed through the microcirculation along with the red blood cells, larger microbubbles, however, were observed to coalesce and interrupt the blood flow. Whether this might influence the tissue oxygen tension is unclear up to now. To examine this question a bolus of 2.4 ml SonoVue™ was injected into the suprarenal aorta at a flow rate of 10 ml/s (a dosage usually applied in the clinic). The pO2 in the outer medulla of the kidney was continuously measured using a flexible pO2 microcatheter. In addition, the SonoVue™ injection and its passage through the renal vasculature were documented by the CEUS technology to assess whether the microbubbles passed the kidney. The study revealed that SonoVue™ induced no changes of the mean oxygen partial pressure in the outer medulla which confirms that these microbubbles on their way through the medullar capillaries did not hinder the co-flow of blood through the renal microvessels in a big animal model with a renal morphology and function comparable to human kidneys. These results demonstrate that the CEUS diagnostic itself did not influence the system to be examined which is a most important prerequisite for any diagnostic method.
