Percutaneous balloon valvuloplasty has become the mainstay of treatment for congenital and acquired valvular stenosis. This section focuses on percutaneous balloon pulmonary and aortic valvuloplasty. Percutaneous balloon pulmonary valvuloplasty (PBPV) Kan was the first to perform successful valvuloplasty for congenital pulmonary stenosis with a balloon dilatation catheter in 1982, and this technique began to be performed at several cardiovascular centers in China in the mid-1980s. After more than 20 years of improvement and development, PBPV has achieved the same efficacy as surgical open-heart surgery with fewer complications and can be an alternative to surgery if the indications are appropriate. Indications PBPV is mainly indicated for typical pulmonary stenosis, mild to moderate dysplastic pulmonary stenosis, or residual stenosis after balloon dilatation or surgery for pulmonary stenosis. With typical signs, a pulmonary transvalvular pressure difference ≥ 30 mmHg, an electrocardiogram suggestive of right ventricular hypertrophy, and an echocardiogram to give a definitive diagnosis. In septal type pulmonary atresia with intact septum, the atretic valve can be perforated by radiofrequency first, followed by balloon dilation. PBPV can also be used as a palliative treatment to relieve hypoxia in patients with complex precordial disease with pulmonary stenosis who are temporarily unable to undergo radical surgery. PBPV is not indicated in patients with (1) severe pulmonary valve dysplasia, (2) combined supra- or subvalvular stenosis, (3) severe right ventricular dysplasia, (4) right ventricle-dependent coronary circulation, and (5) severe tricuspid regurgitation requiring surgical management. Preoperative right heart catheterization and right ventriculography are performed to measure the pulmonary transvalvular pressure difference and annular diameter to evaluate the type and severity of stenosis. A balloon/annular diameter ratio of 1.2 to 1.4 is selected, and a balloon catheter is fed through the femoral vein to the stenosis. The balloon is dilated so that the concave waist (the notch formed on the balloon) disappears quickly, usually for 5 to 10 seconds, and repeated once or twice. Double balloon dilatation is an option for larger annuli where a single balloon is difficult to achieve a suitable balloon/annular ratio. Complications Serious complications include cardiac perforation and pericardial tamponade, which can be fatal. Overselection of the balloon can result in tearing of the pulmonary annulus. Balloon catheters passing through the tricuspid tendon can cause tricuspid tendon injury and severe tricuspid valve insufficiency during dilation. Other vascular complications (venous thrombosis, femoral vein tears, puncture site bleeding), apnea, arrhythmias, and right ventricular outflow tract injury are also present. Proper selection of balloon size and length based on patient weight, annular diameter, and standardization of operation are key to reducing complications. Prognosis In patients with simple PS, PBPV has a good outcome, comparable to that of surgical open-heart surgery, and is now a basic alternative to surgical treatment. The complication rate is about 5％ and the overall mortality rate is <0.5％. Postoperatively, patients have significantly increased activity tolerance and improved right ventricular function. Percutaneous balloon aortic valvuloplasty (PBAV) The first PBAV was successfully performed in 1984 in Lababidi for congenital or acquired aortic stenosis. Since 1989 PBAV has been performed in some cardiac centers in China. Indications PBAV is mainly indicated for typical aortic stenosis without significant annular dysplasia; aortic transvalvular pressure difference ≥50 mmHg at normal cardiac output and no or only mild aortic regurgitation. PBAV is not indicated for (1) moderate or greater aortic regurgitation, (2) dysplastic aortic stenosis, (3) fibromuscular or tubular subaortic stenosis, or (4) supra-aortic stenosis. Procedure Preoperative left heart catheterization and left ventriculography are performed to measure the aortic transvalvular pressure difference and annular diameter to evaluate the nature and severity of the stenosis. A balloon/annular diameter ratio of 0.8 to 1.0 is selected, and a balloon catheter is fed through the femoral artery to the stenosis. The balloon is dilated to make the concave waist disappear quickly, with a dilation time of 5 to 10 seconds, repeated 2 to 3 times. Severe stenosis can be dilated with a small balloon first and then with a larger balloon or double balloon. The criteria for successful PBAV are a decrease in aortic transvalvular pressure difference of 50％ or more, an increase in aortic valve orifice area of 25％ or more, and no significant aortic regurgitation. Prognosis and complications The overall mortality rate of PBAV is around 4％, mostly occurring in the neonatal period. Follow-up in the intermediate and distant stages is rarely reported. Possible complications include aortic regurgitation, vascular complications, perforation of the left ventricle or ascending aorta, mitral valve injury, arrhythmias, and embolism. References [1] Zhou A-Q, Huang M-R, Li Y-F. Percutaneous balloon valvuloplasty. In: Zhou A-Q, ed. Cardiac Catheterization for Congenital Heart Disease. First Edition. Shanghai: Shanghai Science and Technology Press, 2009, 456-481 [2] Rao PS. Percutaneous balloon pulmonary valvuloplasty: state of the art. Catheter Cardiovasc Interv. 2007;69(5):747- 63. 63. review.[3] Akagi T, Hashino K, Maeno Y, Ishii M, Sugimura T, Kawano T, Kato H. Balloon dilatation of the pulmonary valve in a patient with pulmonary atresia and intact ventricular septum using a commercially available radiofrequency catheter. Pediatr Cardiol. 1997;18(1):61-3.( Han L)