Materials and Methods
Study Population
We presented a retrospective study of 228 PVS children who underwent PBPV at the Cardiology Department of Children’s Hospital of Chongqing Medical University from January 2004 to October 2019. All participants in this study were diagnosed with isolated PVS using echocardiography. PVS patients accompanied by patent foramen ovale (PFO), patent ductus arteriosus (PDA), atrial septal defects (ASDs), or ventricular septal defects (VSDs) without hemodynamic compromise were included. Patients with other complex congenital cardiac defects including double-outlet right ventricle, transposition of the great arteries, tetralogy of Fallot, and other heart diseases with hemodynamic compromise were excluded. The study protocol was approved by the Ethics Committee of Children’s Hospital of Chongqing Medical University.
Definition
In this study, quantitative assessment of PVS severity was based mainly on the transpulmonary pressure gradient[8]. Pulmonary stenosis severity was defined based on the 2006 ACC/AHA guidelines on the management of valvular heart disease[9]. The accompanying PR is graded as mild, moderate, or severe[10].
Data collection
Patient and procedural data were retrospectively collected from the electronic patient database at the Pediatric Cardiology Department of Children’s Hospital of Chongqing Medical University from January 2004 to October 2019. All patients completed the preoperative routine examinations, including blood routine, biochemistry, coagulation time, hepatic and renal function, arterial blood gas, 12-lead electrocardiogram (ECG), chest radiography, abdominal ultrasound, transthoracic echocardiography (TTE), cardiac catheterization, and angiography.
Echocardiographic Data
Standard M-mode and two-dimensional echocardiographic views in addition to color Doppler and continuous-wave Doppler were carried out to examine the velocity flow and morphology of the pulmonary valve, peak PVS gradient, right ventricular dimensions, regurgitation of tricuspid and pulmonary valve in addition to its degree, and systolic and diastolic functions of the left ventricular. Using the simplified Bernoulli equation (△P = 4v2), the maximum peak instantaneous systolic pressure gradient was estimated from the transpulmonary flow velocity curve.
Cardiac catheterization and angiography
Venous access was usually achieved via the femoral vein and where the pig tail or balloon floating catheter is inserted for right cardiac catheterization. All procedures were performed with a single balloon. The data acquired from initial PBPV cardiac catheterization and postoperative reports included right ventricular (RV) systolic pressure, pulmonary artery (PA) systolic pressure, RV-PA PSEG, and systemic systolic blood pressure.