Bypass Clear Priming VSD Cardiopulmonary Bypass Circuit Reduce Bypass Associated Inflammation?

February 5, 2026 updated by: Vishal Nigam, Seattle Children's Hospital

Does Clear Priming of the Cardiopulmonary Bypass Circuit Reduce Bypass Associated Inflammation in Ventricular Septal Defect Patients?

The purpose of this trial is to study if priming the pump used during cardiac surgery with non-blood fluids instead of donated blood products reduces the inflammation that occurs after heart surgery. The study will focused on pediatric participants who require open heart surgery to repair certain types holes in the heart.

Typically for pediatric patients, the cardiopulmonary bypass pump is "primed" (filled) with donated blood products. This project is going to test if the exposure to these blood products causes inflammation. Patients experience significant inflammation (swelling) after undergoing cardiopulmonary bypass. This inflammation can interfere and slow down the patient's recovery from cardiac surgery. With this project, the investigator are studying if filling the bypass pump with non-blood products reduces the bypass-associated inflammation.

The investigators are also studying if using non-blood fluids to fill the bypass pump reduces bypass associated side effects.

The investigators are also trying to understand how the inflammation starts. The investigators also want to study genetic material called DNA that is collected from a person's blood. Instructions for the body are contained in parts of DNA called genes. Genes determine things like hair and eye color. The investigator hope by studying genes the investigator can learn more about the inflammation that occurs after heart surgery, but the investigators might use participant's genetic information to study other diseases or conditions other the inflammation that occurs after heart surgery.

The investigators will be studying the recovery of 60 participants between 1 month to 18 months of age who require open heart surgery to repair ventricular septal defects (VSDs), a congenital heart defect where there a hole between the lower chambers of the heart.

Participants will:

Allow for information about how the participants recover from surgery to be collected.

Allow blood samples during and after surgery to be collected to understand how the markers of inflammation change between the two groups (blood versus non-blood priming).

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Cardiopulmonary bypass (CPB) is required for surgical correction/palliation of congenital heart defects. Exposure to CPB results in a robust activation of inflammatory responses. It is now well established that exposure to the CPB circuit is associated with an overwhelming, detrimental systemic inflammatory response. The factors associated with this response may be related to the circuit and exposure to the circuit surface, or may be associated with the body's response to surgical trauma, changes in temperature, etc. Multiple pathways have been shown to be mediating this response, including complement activation, leukocyte activation, endotoxin release, release of oxygen-free radicals, nitric oxide, cytokines, platelet-activation factor, arachidonic acid metabolites and endothelins. Activation of these inflammatory pathways has been implicated in the development of some of the major postoperative complications, such as bleeding tendencies, respiratory insufficiency, renal dysfunction, abnormalities in liver function, and, most seriously, multi-organ failure. Multiple pharmacological therapies have been investigated, with a single aim, to modulate this systemic inflammation. The most widely investigated ones have been corticosteroid administration, use of heparin-coated circuits, leukocyte depletion and ultrafiltration. Despite these efforts, the activation of inflammatory pathways in response to CPB remains a significant clinical problem especially in neonates undergoing CPB.

Over the last several years, several centers including Seattle Children's have been pursuing efforts to restrict the administration of blood products during CPB. In some of the recent publications on the topic, the justifications for moving towards "bloodless CPB" include reducing potential infection risks, consideration that blood products are valuable limited resource, and the concerns of certain religious communities. A limitation of these studies is that they do not examine a patient's clinical course or markers of inflammation in depth. CPB patients experience significant post-CPB inflammation - including increased cytokine levels, inflammatory cell infiltration, vascular leak, and multi-organ dysfunction. In children recovering from complicated cardiac surgeries, increased cytokine levels are associated with high mortality and extended intensive care stays. Typically, a blood-containing prime has been used as a method to preserve high hematocrit levels and maintain oxygen delivery. There are several mechanisms by which exposure to blood products can activate inflammation-which include allergic reactions, cytokines in the blood products, or release of proinflammatory proteins from red blood cells. These mechanisms serve as the basis for the hypothesis that "clear prime" CPB patients will have reduced inflammation as compared to standard of care CPB patients.

Since 5/2021, 174 CPB patients have been operated on at Seattle Children's Hospital (SCH) using restrictive blood management. In 90 of these patients, "bloodless" surgery was attempted. These patients received CPB priming with crystalloid fluids only and without any addition of blood products. These crystalloid fluids are same ones used in current standard of care treatment for pediatric cardiac surgery cases. All other aspects of the patients' treatment were the same including the same bypass machines and tubing. 47 of these patients did not receive blood products during the surgery. 35 patients did not receive any blood products during the hospitalization. There were no statistical differences between the median ventilation time and Intensive Care Unit (ICU) length of stay between the patients operated on with such restrictive blood management as compared to patient controls from our center in which blood products were added to CPB prime.

Dr. Bohuta's recent observational study of 99 SCH neonatal cardiac cases using historical controls identified no statistical difference in postoperative seizures, bleeding events, and lactate levels during CPB between patients who received clear prime versus those who received a blood prime. In this same study, both length of stay and postoperative mechanical ventilation time was shorter in the clear prime group. Hematocrit was consistently lower post-operatively for patients in the crystalloid only group, otherwise, there were no unintended consequences/ adverse events identified in the crystalloid only cohort.

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Washington
      • Seattle, Washington, United States, 98115
        • Seattle Children's Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Weight between 5-10kg
  • Age 1-18 months
  • Requiring cardiopulmonary bypass as part of clinically indicated surgery
  • Surgery performed by Dr. Bohuta or Dr. Greene

Exclusion Criteria:

  • Hemoglobin/hematocrit too low for clear CPB prime (post-dilution Hct <24%)
  • Pre-operative ECMO support
  • Active infection
  • Not clinically appropriate for clear prime (instability, arrhythmias, desaturation, etc.)
  • Genetic syndrome
  • Pork allergy or family requests pork avoidance

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Blood prime
The research participants in this arm will undergo their clinically indicated cardiac surgery. The control group will have the bypass pumped primed with mixture of crystalloid solution and blood, which is currently standard of care.
Experimental: Clear prime
The research participants in this arm will undergo their clinically indicated cardiac surgery. The experimental group will have the bypass pump primed with mixture of crystalloid solution, non-blood fluids.
Procedure: Clear priming of the bypass pump
The intervention is priming the pump with non-blood products.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in RNA expression of the inflammatory marker TNF-α fold pre-cardiopulmonary bypass (CPB) to 24 hours post-CPB
Time Frame: Up to 24 hours post surgery
Plasma from blood samples collected during four timepoints spanning from pre-CPB to 24 hours post-CPB will be analyzed via RNA-Seq to assess changes in TNF-α fold levels. RNA-Seq measures change in gene expression relative to baseline, with higher relative gene expression indicated higher inflammation.
Up to 24 hours post surgery
Changes in protein expression of the inflammatory marker TNF-α fold pre-cardiopulmonary bypass (CPB) to 24 hours post-CPB
Time Frame: Up to 24 hours post surgery
Plasma from blood samples collected during four timepoints spanning from pre-CPB to 24 hours post-CPB will be analyzed ELISA to assess changes in TNF-α fold levels. ELISA measures concentration in picograms per milliliter, with higher scores indicating more inflammation.
Up to 24 hours post surgery
Changes in RNA expression of the inflammatory marker IL8 fold pre-cardiopulmonary bypass (CPB) to 24 hours post-CPB
Time Frame: Up to 24 hours post surgery
Plasma from blood samples collected during four timepoints spanning from pre-CPB to 24 hours post-CPB will be analyzed via RNA-Seq to assess changes in IL8 fold levels. RNA-Seq measures change in gene expression relative to baseline, with higher relative gene expression indicated higher inflammation.
Up to 24 hours post surgery
Changes in protein expression of the inflammatory marker IL8 fold pre-cardiopulmonary bypass (CPB) to 24 hours post-CPB
Time Frame: Up to 24 hours post surgery
Plasma from blood samples collected during four timepoints spanning from pre-CPB to 24 hours post-CPB will be analyzed via ELISA to assess changes in IL8 fold levels. ELISA measures concentration in picograms per milliliter, with higher scores indicating more inflammation.
Up to 24 hours post surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to extubation
Time Frame: From intubation until extubation (up to 24 hours post-surgery)
Clinical data will be collected to measure the number of hours and minutes post-surgery until participants are extubated.
From intubation until extubation (up to 24 hours post-surgery)
Peak lactic acid levels over the first 24 hours post-surgery
Time Frame: Up to 24 hours post-surgery
Clinical laboratory data will be reviewed to identify the highest lactic acid (Normal: ≤2 mmol/L) value recorded within the first 24 hours after surgery. Lactic acid levels (measured in mmol/L) indicate how well the body is delivering oxygen to tissues after surgery.
Up to 24 hours post-surgery
Vasoactive-inotropic score over the first 24 hours post-surgery
Time Frame: Up to 24 hours post-surgery
Clinical data will be collected to determine how much ionotropic support is needed during the first 24 hours after surgery. The vasoactive-inotropic score typically range from 0 to 15, with higher scores indicating a greater need for inotropic support and worse outcomes, and values above 15 are considered atypical.
Up to 24 hours post-surgery
Length of hospital stay post-surgery
Time Frame: From the date of surgery until the date of hospital discharge, assessed up to 90 days post-surgery.
Clinical information will be collected from participants' medical charts to measure the length of hospital stay (in days) after surgery.
From the date of surgery until the date of hospital discharge, assessed up to 90 days post-surgery.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Seattle Children's Hospital

Investigators

  • Principal Investigator: Vishal Nigam, MD, Seattle Children's Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

February 25, 2026

Primary Completion (Estimated)

December 1, 2028

Study Completion (Estimated)

December 1, 2030

Study Registration Dates

First Submitted

April 12, 2024

First Submitted That Met QC Criteria

February 5, 2026

First Posted (Actual)

February 6, 2026

Study Record Updates

Last Update Posted (Actual)

February 6, 2026

Last Update Submitted That Met QC Criteria

February 5, 2026

Last Verified

December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00003941

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Deidentified individual participant data (IPD) that underlie results in publication will be shared.

IPD Sharing Time Frame

At the time of publication, deidentified IPD will be shared.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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