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

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

RECRUITING

Total Enrollment

92 participants

Study Classification

OBSERVATIONAL

Study Start Date

2022-02-15

Study Completion Date

2025-12-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

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 of chronic kidney disease. The pathophysiology of AKI in cardiac surgery is complex and still partly unknown.Recently a technique has been described that allows to measure the blood velocity in the right renal artery and in the superior mesenteric artery using the transesophageal echocardiogram (TEE); this technique allows to view these arteries and measure the speed of the blood with good precision because the insonation angle (ie the angle formed by the ultrasound flow and the direction of the blood vessel) is adequate. In cardiac surgery, this methodology allows you to monitor blood velocity in the right renal artery and superior mesenteric artery during surgery. Some authors have used it to conduct pilot studies in which the blood velocity values in the renal arteries during cardiac surgery were used to calculate the pulsatility and resistivity indices, as predictors of the risk of postoperative AKI. At present, therefore, despite the fact that TEE is routinely used for monitoring renal perfusion during cardiac surgery, the blood velocity in the renal and mesenteric arteries has been little studied during cardiopulmonary by-pass (CPB) and has never been evaluated during CPB with continuous flow; in particular, the possible variation in blood velocity measured during CPB compared to the baseline values measured before extracorporeal circulation and its correlation with the onset of postoperative renal failure is not known.

Related Clinical Trials

Explore similar clinical trials based on study characteristics and research focus.

Respiratory Variations of the Diameter of Superior Vena Cava for Predicting Fluid Responsiveness After Cardiac Surgery

NCT03393897

Transesophageal Echocardiography Vena Cava Superior

COMPLETED

Continuous Monitoring of Right Ventricular Function, Based on the Correlation Between the C-X Segment of the Central Venous Pressure Curve, and the Echocardiographic Evaluation of Right Ventricular Systolic Function

NCT03295669

Heart Surgery Ultrasonography Right Ventricle Systolic Function

COMPLETED

The Consistency of Cardiac Output Measured by Pulmonary Artery Catheter and LiDCO in Cardiac Surgical Patients

NCT04604886

Cardiac Surgery Cardiac Output

UNKNOWN NA

Inferior Vena Cava Compliance in Trans-thoracic Echocardiography: is the Trans-hepatic Window as Reliable as the Subcostal One

NCT04866095

Surgical Procedure, Unspecified

COMPLETED NA

Right Ventricular Echocardiography in caRdiac SurgEry

NCT03301571

Right Ventricular Dysfunction

COMPLETED NA

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

The cardiopulmonary by-pass (CPB) 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 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 (RRT) in the postoperative period presenting a mortality that can reach 50-70%. However, even more limited increases in serum creatinine (sCr) are associated with worsening prognosis and the risk of chronic kidney disease (CKD). The pathophysiology of AKI in cardiac surgery is complex and still partly unknown. It is believed that one of the main causative factors is hypoperfusion and renal hypoxia, in particular of the medullary region; this would result in a vasoconstriction of the afferent arterioles to the glomerulus and a reduction in filtration. Risk factors associated with the increased incidence of AKI include bleeding, use of the aortic pump, excessive cardiopulmonary bypass duration, excessive haemodilution, insufficient pump flow, or insufficient blood pressure. Hypothermia, which also has a protective effect against hypoperfusion and tissue hypoxia, could induce AKI by increasing renal vascular resistance and favoring medullary hypoxia during subsequent rewarming.

In addition to AKI, another complication of cardiac surgery, rarer but associated with a higher mortality, is acute mesenteric ischemia; the most frequent type is non-occlusive mesenteric ischemia (NOMI) which seems to have as a predisposing cause a reduction or maldistribution of splanchnic blood flow and the use of vasoconstrictors.

Recently a technique has been described that allows to measure the blood velocity in the right renal artery and in the superior mesenteric artery using the transesophageal echocardiogram (TEE); this technique allows to view these arteries and measure the speed of the blood with good precision because the insonation angle (ie the angle formed by the ultrasound flow and the direction of the blood vessel) is adequate. In cardiac surgery, this methodology allows you to monitor blood velocity in the right renal artery and superior mesenteric artery during surgery. Some authors have used it to conduct pilot studies in which the blood velocity values in the renal arteries during cardiac surgery were used to calculate the pulsatility and resistivity indices, as predictors of the risk of postoperative AKI. The calculation of these indices, however, requires the use of a pulsatile blood flow to generate a periodic variation of the blood velocity, and they are not evaluable during CPB since the current practice in almost all centers is to use a continuous blood flow. At present, therefore, despite the fact that TEE is routinely used for monitoring renal perfusion during cardiac surgery, the blood velocity in the renal and mesenteric arteries has been little studied during CPB and has never been evaluated during CPB with continuous flow; in particular, the possible variation in blood velocity measured during CPB compared to the baseline values measured before extracorporeal circulation and its correlation with the onset of postoperative renal failure is not known.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Heart Surgical Procedure

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Observational Model Type

COHORT

Study Time Perspective

PROSPECTIVE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Heart Surgical Patients

Patients with cardiovascular disease, who must undergo cardiac surgery in extracorporeal circulation with continuous flow

transesophageal echocardiogram

Intervention Type DIAGNOSTIC_TEST

To measure mean blood velocity at the level of the right renal and superior mesenteric artery

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

transesophageal echocardiogram

To measure mean blood velocity at the level of the right renal and superior mesenteric artery

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* age\> 18 years
* written informed consent
* cardiac surgery with cardiopulmonary bypass (CPB)
* New York Heart Association (NYHA) class I, II, III
* preoperative serum creatinine less than 1.2 mg / dl

Exclusion Criteria

* contraindications to Trans Esophageal Ultrasound (TEE) based on American Society of Anesthesiologists (ASA) recommendations (esophageal or gastric diseases or previous surgery)
* history of non-coronary arterial pathologies
* atrial fibrillation
* preoperative serum creatinine greater than 1.2 mg / dl • NYHA class IV
* emergency cardiac surgery

Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No