Balloon Aortic Valvuloplasty

Following the description by Lababidi in 1983 of balloon aortic valvuloplasty, it has been adopted by several groups of workers for relief of aortic valve stenosis. The indications for the procedure are peak-to-peak systolic pressure gradients in excess of 50 mmHg with symptoms or ECG changes or a gradient greater than 70 mmHg irrespective of the symptoms or ECG changes. One or more balloon dilatation catheters are placed across the aortic valve percutaneously, over extra-stiff guide wire (s) and the balloon (s) inflated until waist produced by the stenotic valve is abolished. A balloon/annulus ratio is 0.8 to 1.0 is recommended. While trans-femoral arterial route is the most commonly used for balloon aortic valvuloplasty, trans-umbilical arterial or venous or trans-venous routes are preferred in neonate and young infants to avoid femoral arterial injury. Reduction of peak-to-peak systolic pressure gradient along with a fall in left ventricular peak systolic and enddiastolic pressures is seen after balloon aortic valvuloplasty in the majority of patients. Significant aortic insufficiency, though rare, may develop, particularly in the neonate. At intermediate-term follow-up, peak-to-peak gradients, at repeat cardiac catheterization and noninvasive Doppler gradients remain low for the group as a whole. Nevertheless, restenosis, defined as peak-to-peak gradient ≥ 50 mmHg may develop in nearly one quarter of the patients. Predictors of restenosis are age ≤ 3 years and an immediate post-valvuloplasty aortic valve gradient ≥ 30 mmHg. The restenosis may be addressed by repeat balloon valvuloplasty or surgical valvotomy. Feasibility and effectiveness repeat balloon valvuloplasty in relieving restenosis has been demonstrated. Long-term follow-up data suggest, low Doppler peak instantaneous gradients, minimal additional restenosis beyond what was observed at intermediate-term follow-up and progression of aortic insufficiency in nearly one-quarter of patients. Event-free rates are in mid 70s and low 60s respectively at 5 and 10-years after initial balloon valvuloplasty. A number of complications have been reported, but are rare. Comparison with surgical results is fraught with problems, but overall, the balloon therapy appears to carry less morbidity. Immediate, intermediate and long-term follow-up data following balloon aortic valvuloplasty suggest reasonably good results, avoiding/postponing the need for surgical intervention. However, late follow-up data indicate that significant aortic insufficiency with left ventricular dilatation may develop, some require surgical intervention and are of concern. Current recommendations favor balloon valvuloplasty as first line therapeutic procedure for relief of aortic valve stenosis. *Corresponding author: P. Syamasundar Rao, MD, Professor of Pediatrics & Medicine, Emeritus Chief of Pediatric Cardiology, UT-Houston Medical School, 6410 Fannin Street, UTPB Suite # 425, Houston, TX 77030, USA, Tel: 713-5005738; Fax: 713-500-5751; E-mail: [email protected] Received June 05, 2012; Accepted June 22, 2012; Published June 24, 2012 Citation: Agu NC, Syamasundar Rao P (2012) Balloon Aortic Valvuloplasty. Pediat Therapeut S5:004. doi:10.4172/2161-0665.S5-004 Copyright: © 2012 Agu NC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction Congenital aortic stenosis makes up 5% to 6% of all congenital heart defects. It occurs four times more frequently in males than females. Although the pathology of stenosis varies, the most common is a bicuspid valve with commissural fusion. Unicuspid aortic valves are more prevalent in neonates with critical stenosis while bicuspid valves are common in childhood. Aortic stenosis is a progressive disorder with worsening severity of obstruction with increasing age. The treatment of choice for congenital aortic valve stenosis has varied from surgical valvotomy in the past to balloon aortic valvuloplasty at the present. The technique of balloon valvotomy of stenotic pulmonary and tricuspid valves with a modified ureteral catheter was first described by Rubio and Limon-Lason [1] in the early 1950s. Double lumen balloon catheters developed by Gruntzig and their associates [2], based on the concepts of Dotter and Judkins [3], were utilized for dilatation of coarcted aortic segments [4-6] and valvar pulmonary stenosis [7]. Subsequently this technique was extended to the aortic valve by Lababidi and his associates [8] in 1983. Shortly thereafter this technique has been adopted by other workers and reports of immediate, intermediate-term and long-term results of balloon aortic valvuloplasty have been published [9-12]. The purpose of this review is to discuss the technique and results of balloon aortic valvuloplasty. Assessment of Aortic Valve Severity Assessment and diagnosis of aortic valvar obstruction is made by clinical examination, roentgenographic, electrocardiographic and echo-Doppler (Figure 1) studies. Once a diagnosis of moderate to severe obstruction is made, cardiac catheterization and cineangiography is performed to confirm the clinical impression and to consider balloon aortic valvuloplasty [9,10]. The most usual method of assessing the severity of obstruction is pressure pullback tracings across the aortic valve (Figure 2) during cardiac catheterization; however, the most accurate method is simultaneous left ventricular and aortic pressure measurement (Figure 3). Since the availability of echo-Doppler studies, this non-invasive method is used for selection of candidates for cardiac catheterization and will be detailed in the next section.