This is a prospective, multi-center, single-arm clinical trial to evaluate the safety and efficacy of Iron Bioresorbable Scaffold System (IBS Angel) in patients with pulmonary artery stenosis.

82 patients with pulmonary artery stenosis will be treated with the Iron Bioresorbable Scaffold System (IBS Angel) developed by Biotyx Medical (Shenzhen) Co., Ltd. This study is designed as a prospective, multi-center, single-arm clinical trial. Enrolled patients will undergo IBS Angel implantation and will be followed up at 1, 3, 6, 12, and 24 months post-procedure.

Inclusion Criteria:

1. Patients must between 1 and 14 years old.

2. Patients who have congenital or secondary pulmonary artery stenosis (including pulmonary artery trunk, left pulmonary artery and right pulmonary artery), and meeting one of the following criteria:

   A: The pressure gradient across the stenosis ≥20mmHg measured by catheter; B: The degree of pulmonary artery stenosis ≥50% ( calculated by (diameter of adjacent normal segments - residual lumen diameter of the stenosis segment)/diameter of adjacent normal segments ×100%); C: The ratio of right ventricular systolic pressure to aortic systolic pressure ≥50%.

3. Patients and whose family have high compliance, voluntarily participate in and sign the informed consent form, and complete the 2-year follow-up.

4. Patients have life expectancy >2 year after successful stent implantation.

Exclusion Criteria:

1. Patients who have a history of disease related to iron overload or iron disorder, such as hereditary hemochromatosis, etc.
2. Patients with cardiopulmonary function that cannot tolerate surgery, such as severe heart failure (NYHA Grade III and above) that cannot be controlled by active medical treatment.
3. Patients with known allergy to contrast agent, iron and its degradation products.
4. Patients with hemorrhagic disorders.
5. Patients with contraindications on antiplatelet agents and anticoagulant therapy.
6. Patients with thrombosis at the vascular wall of target lesion or the distal or proximal location.
7. Patients with known severe renal or hepatic insufficiency which are unsuitable for index procedure as per investigator judgement.
8. Previous stent implantation has been performed to treat the target lesion;
9. Patients with severe stenosis or excessive tortuosity in the targeted vessels, or anatomical abnormalities, making it difficult for device to reach the target lesion.
10. Other conditions that are not suitable for stent delivery or balloon expansion.
11. Patient who have already participated in another drug or medical device clinical trial that have not yet completed or withdrawn within 3 months before the screening period of this trial.
12. Patients who are not suitable for participating the trial as per investigator judgement.