Percutaneous balloon pulmonary valvuloplasty: state of the art.
Since the first description of balloon pulmonary valvuloplasty in 1982 by Kan, the procedure has been extensively utilized by several groups of workers for relief of pulmonary valve stenosis. It is generally recommended that the procedure be performed for peak-to-peak gradients in excess of 50 mmHg. The technique involves positioning one or more balloon catheters across the stenotic valve, usually over an extra-stiff guide wire and inflating the balloons with diluted contrast material, thus producing valvotomy. The procedural details are described in this paper. The currently recommended balloon/annulus ratio is 1.2 to 1.25. Immediate reduction of gradient, increase in jet width and free motion of the pulmonary valve leaflets with less doming have been observed following balloon dilatation. Improvement of right ventricular function, tricuspid insufficiency and right-to-left shunt has also occurred. Complication can occur, but are rare and minimal. At mid-term follow-up, both catheterization measured peak-to-peak gradients and Doppler-measured peak instantaneous gradients remain improved for the group as a whole. However, restenosis, defined as gradient >or=50 mmHg, has been observed in nearly 10% of children. Predictors of restenosis include balloon/annulus ratio <1.2 and immediate post-valvuloplasty gradient >or=30 mmHg. Small pulmonary valve annulus, earlier study year and post-surgical complex pulmonary stenosis have also been identified as factors predictive of restenosis. Redilatation with balloons that are larger than those used at the time of initial balloon valvuloplasty produces excellent results and redilatation is the procedure of choice in the management of restenosis after previous balloon pulmonary valvuloplasty. Long-term follow-up results are scanty, but the limited data reveal minimal additional restenosis, event-free rates in mid-80s and mid-70s at 10 and 15 years respectively and significant increase in prevalence of pulmonary insufficiency. Balloon pulmonary valvuloplasty is equally successful in neonates as well as in adult subjects. In conclusion, balloon pulmonary valvuloplasty is the treatment of choice for relief of pulmonary valve stenosis. Use of balloons 1.2 to 1.25 times larger than pulmonary valve annulus may produce optimal results. Life-long follow-up to identify the significance of residual pulmonary insufficiency is indicated.
Rao
P Syamasundar
PS
Division of Pediatric Cardiology, The University of Texas/Houston Medical School, Children's Memorial Hermann Hospital, Houston, Texas.
D000367:Age Factors; D002404:Catheterization / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D004869:Equipment Safety; D006083:Graft Occlusion, Vascular / Q000209:etiology; D006801:Humans; D011666:Pulmonary Valve Stenosis / Q000628:therapy*; D019233:Retreatment; D013997:Time Factors