Blood Velocity Variation in Right Renal and Superior Mesenteric Arteries During Cardio-pulmonary Bypass

The cardiopulmonary by-pass technique, used in cardiac surgery to obtain a bloodless operating field and an immobile heart, determines important effects on the blood vessel wall, especially when a continuous and non-continuous blood flow is used. In fact, a reduction in Nitric Oxide (NO) production by the endothelium, an increase in systemic vascular resistance and an increased risk of cerebral and renal hypoperfusion have been observed and can result in potential organ damage. Acute kidney injury (AKI) after heart surgery is a major cause of mortality and morbidity. Its incidence varies according to different definitions, but can reach 30%. In some series, 1-5% of patients require renal replacement therapy in the postoperative period presenting a mortality that can reach 50-70%. However, even more limited increases in serum creatinine are associated with worsening prognosis and the risk