Congenital heart disease occurs in about 1% of live births and can range from (1) naturally curable conditions that require no treatment to (2) conditions that require multiple immediate operations or refractory severe conditions. In the course of a staged surgical intervention, adhesion formation around the heart and large vessels can occur, and dissection of the adhesion site is required at the time of reoperation. There is a concern that dissection may markedly increase the risk of operation such as prolonged surgical time, cardiovascular injury, and increased blood loss, and medical devices to prevent adhesion formation after operation in the field of pediatric cardiovascular operation are strongly desired in medical settings.

The investigational product (BAX602), which has already been manufactured and marketed by Baxter overseas, has been used for open heart surgery as a local hemostatic agent without biological materials in Europe and the US for more than 20 years.

However, since it has not been approved in Japan, this randomized controlled study will be conducted in Japan to demonstrate the effect of BAX602 to prevent and reduce adhesion formation between the surface of the heart/large vessels and surrounding tissues in pediatric patients undergoing planned multistage operation for congenital heart disease.

Inclusion Criteria:

1. Patients <12 years of age

2. Patients who have undergone the first scheduled palliative surgery for the following diseases and are scheduled to undergo re-do open heart surgery (anatomical repair surgery):

   • Ventricular septal defect
   • Atrioventricular septal defect
   • Tetralogy of Fallot (spectrum)
   • Single ventricle disease (The participant should not meet the exclusion criteria (1) to (3)).

3. Patients who will undergo BT shunting or pulmonary artery banding (including bilateral pulmonary artery banding) for the first surgery

4. Patients undergoing repair surgery (anatomical repair surgery) or bi-directional Glenn surgery as the second target procedure

5. Patients for whom written consent has been obtained from the patient or a surrogate

Exclusion Criteria:

1. Patients with hypoplastic left heart syndrome (HLHS) and its analogues.
2. Patients with asplenia or hypersplenism.
3. Patients undergoing Norwood surgery as the second surgery.
4. Patients undergoing open heart surgery prior to the first scheduled palliative surgery.
5. Patients with complications of other organs that affect the indication for cardiac surgery.
6. Patients with chromosomal or genetic abnormalities that may affect the indication for cardiac surgery.
7. Patients with severe infections or multiple organ failure.
8. Patients who require emergency surgery that requires emergency life support.
9. Patients' body weight is less than 2,500g at birth.
10. Patients who are participating in other clinical trials or who are scheduled to participate in other clinical trials during this study period.
11. Patients who are judged by the investigator or sub investigator to be inappropriate to participate in this study for other reasons.

Sharing of Clinical Trial Data: Baxter is committed to sharing clinical trial data with external medical experts and scientific researchers in the interest of advancing public health. As such, Baxter will supply anonymized Individual Patient Datasets (IPD) and supporting documents (synopsis of clinical study reports, protocol and SAP's)

Upon approval of a legitimate research request.

Research requests will be reviewed by qualified medical and scientific experts within the company. If Baxter agrees to the release of clinical data for research purposes, the requestor will be required to sign a data sharing agreement (DSA) in order to ensure protection of patient confidentiality and any intellectual property rights of Baxter prior to the release of any data.