Inclusion Criteria:
1. Age ≥ 18 years
2. Sufficient appropriate tissue (preferably: Pericardium for pericardiectomy via thoracoscopy or thoracotomy, or sternotomy; other options are fascia lata, rectus fascia, peritoneum or diaphragm)
3. Any of the following by transthoracic echocardiography and/or Cardiac Magnet Resonance Imaging:
* For patients in New York Heart Association (NYHA) Classification II, III, or IV: Moderate (3+) or severe (4+) pulmonary regurgitation AND/OR mean systolic gradient across PV or RVOT ≥ 35 mmHg
* For patients in NYHA Classification I: Severe (4+) pulmonary regurgitation with RV dilatation or dysfunction and/or mean PV or RVOT systolic gradient ≥ 40 mmHg
* Right ventricular ejection fraction (RV-EF): \<40%.
* Right ventricular end-diastolic volume (RVEDV): \>150 ml/m2 (body surface area)
4. Written informed consent provided by study subjects obtained before any research-related test is performed
Exclusion Criteria:
* Active endocarditis or myocarditis or within 3 months before the screening date
* Patients unwilling or unable to provide written informed consent or comply with follow-up requirements
* Obstruction of the central veins (including the superior and inferior vena cava, and bilateral iliac veins) such that the Ensemble-delivery system/ Performer™ - Guiding Sheath/ Extra Large Check-Flo® or GORE® DrySeal Flex + Ballon-in-Ballon-catheter cannot be advanced to the heart via a transvenous approach from either femoral vein or internal jugular
* Requires emergency surgery
* Recipient of transplanted organs or currently an organ transplant candidate
* Pulmonary hypertension
* Connective tissue disorders
* Coronary artery disease
* Immunosuppressive disease
* Estimated survival of less than 6 months
* Fertile females unable to take adequate contraceptive precautions (PEARL- Index \< 1%)
* Females who are pregnant, or are currently breastfeeding an infant
* Acute myocardial infarction within 30 days of the screening date
* Stroke confirmed by CT, cerebrovascular accident (CVA), or transient ischemic attack (TIA) within 6 months before the screening date
* Hemodynamic or respiratory instability requiring inotropic or/and mechanical circulatory support, or mechanical ventilation within 30 days before the screening date
* Severe left ventricular systolic dysfunction with ejection fraction ≤ 20% or evidence of an intra-cardiac mass, thrombus, or vegetation assessed by echocardiography before the screening date
* Renal insufficiency with creatinine level 2.5 mg/dl within 60 days before the screening date
* Leukopenia with WBC \<3.5 x 109/L anemia with Hgb \<10 g/dl, or thrombocytopenia with platelet count \<50x103/l accompanied by a history of bleeding diathesis or coagulopathy within 60 days before the screening date
* Adult subject is an illicit drug user, alcohol abuser, or unable to give informed consent
* Subject is institutionalized by court order or by order of authority (e.g. prisoner, untreated psychiatry; limited compliance)
* Major or progressive non-cardiac disease (liver failure, renal failure, cancer)that has a life expectancy of less than six months Inability to comply with all of the study procedures and follow-up visits
* Subjects who are dependent on the sponsor or investigators
