no Inclusion

Acute renal failure after cardiac surgery is a common postoperative complication, affecting approximately 20% of patients. It is associated with an increase in short-term mortality and an increase in hospital stay; but is also associated with an increase in long-term mortality of up to 30% at 5 years, even if renal function recovers upon discharge.

Its origin is multifactorial: intraoperative hypoperfusion, including hemodynamic variations related to extracorporeal circulation or bleeding, postoperative hypoperfusion related to cardiogenic or vasoplegic shock, ischemia-reperfusion phenomena leading to cell lysis or inflammation at the tubular level, inflammation and oxidative stress related to extracorporeal circulation, and hemolysis are the main causes.

Hydro-sodium overload and associated venous congestion is also one of the etiologies of acute renal failure in post-operative cardiac surgery and is associated with increased mortality. The proposed pathophysiological mechanism is based on the decrease in renal tissue perfusion pressure due to the increase in venous pressure. In the extreme, the increase in pressure in the renal capsule could lead to true renal ischemia due to engorgement. This renal congestion can be diagnosed based on clinical signs, biological signs (such as NT-pro-BNP) or by monitoring by central venous pressure (CVP). However, these statistical tools have low diagnostic performance, and new tools based on ultrasound and Doppler are being developed. Indeed, alterations in venous flow in the renal, suprahepatic and portal veins, reflecting the increase in pressures there, are associated with the onset of acute renal failure in post-operative cardiac surgery.

More recently, a retrospective postoperative cardiac surgery study assessed venous congestion using the VEXUS (Venous Excess UltraSound) composite score. This score explores the diameter of the inferior vena cava (IVC) and venous flows in the hepatic, portal, and renal veins, and is associated with acute renal failure. Its diagnostic performance is based on the joint analysis of all Doppler flows and offers better diagnostic performance than isolated CVP measurement.

The primary objective of this study is to prospectively investigate this ultrasound score and its association with the development of acute renal failure postoperatively after cardiac surgery. Due to the morbidity and mortality associated with renal failure described above, a secondary objective of the study is to investigate the association between the VEXUS score and the development of chronic renal failure.

Inclusion Criteria:

• Adult patient undergoing valve surgery and/or bypass surgery under cardiopulmonary bypass (CPB).
• Patient who has read and understood the information letter and does not object to participating in the study.
• Member of or beneficiary of a social security scheme.

Exclusion Criteria:

• Age under 18 years
• Severe chronic kidney disease with glomerular filtration rate (GFR) < 30 mL/min/1.73 m² and/or requiring dialysis treatment
• Kidney, heart, and liver transplant recipients
• Acute kidney failure at the time of inclusion, defined by KDIGO criteria
• Coronary artery bypass grafting without CPB
• Conditions that may interfere with portal and liver Doppler imaging (cirrhosis, suspected cirrhosis, portal thrombosis)
• Mechanical left ventricular support
• Circulatory support such as ECLS
• Pregnant women
• Patient refusal
• Protected incapacitated persons (judicial protection, guardianship, curatorship, deprivation of liberty)

Adult patient undergoing valve surgery and/or bypass surgery under extracorporeal circulation (ECC).

The data provided will be the property of the sponsor and will be used solely for its own research activities.