The "Pleiades" study is a non randomised, prospective, single center clinical trial that aims to evaluate the safety and the procedural feasibility of an innovative flow assist device (Pleioflow-RF) in adult patients undergoing elective cardiac surgery.

This is a non randomised, prospective, single center clinical study that aims to evaluate the safety and the procedural feasibility of an innovative flow assist device (Pleioflow-RF) in adult patients, undergoing elective cardiac surgery. The Pleioflow-RF is a percutaneous flow assist device that functions in combination with the traditional Intra Aortic Balloon (IAB). It represents a modified, probably improved, safer and more potent version of the latter, with respect to its dramatic ability to increase renal perfusion in low flow and pressure conditions -as displayed in large animal trials.

The Pleioflow RF -IAB assembly integrates two critical elements:

(i) a soft Nitinol stent element, positioned at the tip of the IAB, deployed in the descending Aorta that centralizes the IAB, thus preventing excessive IAB movement, protecting the wall of the Aorta from IAB induced injury, and the renal arteries from occlusion, (ii) a downstream valve, mounted within the above stent, that keeps the pressure and flow augmentation, created by the IAB's periodic inflation, localised below said valve, in the abdominal Aorta, where the renal arteries originate.

The device is used intraoepratively, during Cardiopulmonary by pass (CPB). During IAB inflation, the IAB occupies space and the pressure increases instantly. The downstream valve above the IAB, receives this pressure wave and closes. The valve closure blocks upstream flow, and diverts all the flow and pressure wave generated by the IAB primarily towards the kidneys and the periphery.

Due to the continuous IAB's perdiodic inflation and deflation, the device converts the constant CPB flow and pressure to pulsatile, towards the kidneys.

The device is expected to increase substantially the renal perfusion during Cardiac Surgery; it may therefore decrease the post-operative incidence of renal failure.

The hypothesis of this clinical study is that the placement of the Pleioflow-RF intraoperatively, particularly in patients who are more prone to developing renal deterioration based on either their Cleveland Clinic prognostic score, or/and the pre-existence of renal impairment, can prevent further renal deterioration in these patients. These vulnerable patients comprise 10-20% of the total cardiac surgery population.

Following informed consent, subjects eligible for a elective cardiac surgery that meet all of the inclusion, and none of the exclusion, criteria will be enrolled into the study. The Pleioflow-RF will be inserted preferrably through a 9F sheath into the femoral artery; then advanced into the descending thoracic aorta, and positioned below the origin of the left subclavian artery under transoesophageal echocardiography guidance. Subsequently through the same sheath, the intra-aortic balloon (IAB) will be placed and be advanced up to the proximal tip end of the Pleioflow-RF device. The IABP will be connected to an IAB pump. The duration of operation of the assembly (Pleioflow-RF and the IAB) will be for as long as the cardiopulmonary bypass(CPB) time, in order to protect the kidneys from hypoperfusion, during that time. After the end of the CPB, the IABP and the device will be removed. Subjects will be followed up until 30 days post intervention.

Inclusion Criteria:

1. Age ≥ 18 and ≤ 85, men and women
2. Elective coronary artery bypass grafting surgery and/or heart valve surgery with planned CPB.
3. Written informed consent provided
4. Haemoglobulin (Hb) ≥ 11 g/dl in women and ≥ 12 g/dl for men
5. Ejection fraction ≥ 30%
6. Score≥ 3 according to the Cleveland Clinic Foundation risk factor scale for AKI and / or Chronic Kidney Disease (CKD) with preoperative glomerular filtration rate, estimated glomerular filtration rate, eGFR ≤50 ml / min / 1.7, 3 m2) as estimated by the equation of four Modified Diet and Renal Disease variables (MDRD type)

Exclusion Criteria:

1. emergency surgery
2. severe sepsis or rhabdomyolysis
3. severe preoperative renal insufficiency requiring renal replacement therapy (RRT) or even once RRT
4. receiving within the last 10 days nephrotoxic medications, such as radiocontrast material (> 100 ml), amphotericin B, aminoglycosides, NSAID, or trimethoprim-sulfamethoxazole with at least moderate renal impairment (eGFR ≤45)
5. Any severe coagulopathy
6. Participation in another trial
7. Any surgical or medical condition which according to investigator's opinion could create problem in the assessment of safety and /or efficacy of the device
8. Severe comorbidity with life expectancy < 6 months
9. History of poor compliance with previous treatment and incapability of giving informed consent
10. Pregnant or breastfeeding women. Pregnancy, confirmed by a positive laboratory test for Human Chorionic Gonadotropin, is considered from the time after conception until the end of the pregnancy.
11. Peripheral artery disease making insertion of IABP unfeasible
12. Preoperative intra-aortic balloon pump (IABP)
13. Preoperative other device in the same anatomical area (which could possibly create dysfunction of any of the other two devices)