Transcatheter treatment of pulmonary outflow tract obstruction: A review

The role of transcatheter methods in the management of pulmonary outflow tract obstruction are discussed in this review. Balloon pulmonary valvuloplasty for relief of isolated pulmonary valve stenosis has been successfully used by many investigators and is the procedure of choice for the management of these lesions. Supravalvar pulmonic stenosis, if discrete, can be relieved by balloon dilatation. Cyanotic children with interatrial right-to-left shunts secondary to severe valvar pulmonary stenosis respond in a manner similar to that observed with isolated pulmonary valve stenosis. In these patients, balloon valvuloplasty is the treatment of choice and may be corrective in most patients. In patients with interventricular right-to-left shunting secondary to pulmonary outflow tract obstruction and in patients with narrowed BT shunts, balloon dilatation may be an effective palliative procedure in a substantial proportion of patients obviating the need for an initial or second palliative shunt. Balloon dilatation is recommended if the patient's size or cardiac anatomy make them unsuitable for safe total surgical correction. In patients with pulmonary atresia, either initial opening of the atretic pulmonary valve by laser or by surgery with subsequent balloon dilatation are potentially beneficial in reducing the total number of surgical procedures that these children are likely to require. However, further clinical trials are needed before their general use.     

Double Balloon Technique for Percutaneous Balloon Pulmonary Valvuloplasty: Comparison with Single Balloon Technique

This study was designed to document our results of double balloon pulmonary valvuloplasty and to evaluate if the double balloon technique is preferable to single balloon valvuloplasty in the relief of isolated valvar pulmonic stenosis. Double balloon valvuloplasty in twelve patients reduced the pulmonary valvar gradient from 100.5 ± 28.0 (mean ± SD) to 26.6 ± 12.5 mm Hg (P < 0.001) which remained improved, 17.5 ± 10.2 mm Hg (P < 0.001) at 6 to 14 month follow-up. Single balloon valvuloplasty with equivalent balloon/pulmonary valve annulus ratios (1.19 ± 0.14 vs 1.19 ± 0.15, P > 0.1) in another 12 patients also reduced (P < 0.001) the gradient from 96.3 ± 40.1 to 28.3 ± 17.3 mm Hg immediately following the procedure which at 6 to 13 month follow-up was 12.8 ± 9.9 mm Hg. The right ventricular peak systolic pressures (116.6 ± 24.5 vs 113.8 ± 41.5 mm Hg) and pulmonary valvar gradients (100.5 ± 28.0 vs 96.3 ± 40.1 mm Hg) prior to valvuloplasty, residual right ventricular pressures (47.4 ± 12.2 vs 54.3 ± 14.2 mm Hg) and pulmonary valve gradients (26.6 ± 12.5 vs 28.3 ± 17.3 mm Hg) immediately after valvuloplasty, and residual right ventricular pressures (43.1 ± 10.9 vs 41.1 + 12.5 mm Hg) and pulmonary valvar gradients (17.5 ± 10.2 vs 12.8 ± 9.9 mm Hg) on follow-up were similar (P ± 0.1) in both groups.
These data indicate that results of double balloon valvuloplasty are excellent but not superior to single balloon valvuloplasty. It is suggested that the double balloon valvuloplasty should be used if the pulmonary valve annulus is too large to dilate with a single balloon. There is no need for double balloon valvuloplasty if the pulmonary valve can be dilated with a commercially available single balloon.     

Significance of infundibular obstruction following balloon valvuloplasty for valvar pulmonic stenosis

This study was designed to define the prevalence and significance of infundibular obstruction following balloon pulmonary valvuloplasty. Thirteen of 62 children had infundibular gradients prior to valvuloplasty; five of these disappeared following balloon valvuloplasty. Five other children without pre-valvuloplasty infundibular gradients but with angiographic infundibular narrowing developed new infundibular gradients following valvuloplasty. Propranolol was administered to six children because of severe infundibular constriction, with improvement. None required surgical intervention. At follow-up the infundibular gradients either diminished or disappeared. The infundibular gradients appear to be more frequent with increasing age and severity of pulmonary valvar obstruction. Children developing systemic or suprasystemic right ventricular pressures after balloon pulmonary valvuloplasty may be candidates for propranolol therapy. Regression of the infundibular stenosis at follow-up can be expected, as has been observed after surgical pulmonary valvotomy. Because the infundibular obstruction can be successfully managed, balloon pulmonary valvuloplasty remains the treatment of choice for isolated valvar pulmonary stenosis. Use of balloon valvuloplasty in children less than 5 years of age and/or prior to development of pulmonary gradients in excess of 80 mm Hg may reduce the chance for development of infundibular reaction.     

Current treatments for congenital aortic stenosis

PURPOSE OF REVIEW: Congenital valvar aortic stenosis is a challenging disease that often requires repeated palliative procedures. Stenosis can range from mild and asymptomatic, not requiring intervention, to severe, as seen in hypoplastic left heart syndrome. New advances such as fetal balloon valvuloplasty, improvements in the Ross technique, and long-term studies of trans-catheter balloon valvuloplasty and surgical valvotomy warrant a review of the outcomes and optimal timing of the various interventions. RECENT FINDINGS: Fetal balloon valvuloplasty has shown promise. Despite some mortality and morbidity, some fetuses are showing significant growth in left ventricular structures, allowing biventricular repair. In neonates and infants with congenital aortic stenosis, excellent initial results are obtained with trans-catheter balloon valvuloplasty, although stenosis resistant to further balloon dilation or regurgitation may develop, necessitating surgical intervention. Midterm results from the Ross procedure are encouraging, demonstrating low rates of mortality, aortic insufficiency and re-intervention. Stenosis of the pulmonary allograft may be inevitable, and recent long-term follow-up suggests an increase in aortic insufficiency. SUMMARY: While availability of fetal balloon valvuloplasty is limited, it has promise for promoting in-utero left ventricle growth and improving function. The optimal procedure for infants and neonates is trans-catheter balloon valvuloplasty. For older patients, the Ross procedure is the repair of choice, although more long-term studies are needed to assess the natural course of the autograft. Outcomes should improve with advances in pulmonary allografts.     

Semilunar Valve Interventions for Congenital Heart Disease: JACC State-of-the-Art Review

Transcatheter balloon valvuloplasty for the treatment of aortic and pulmonary valve stenosis was first described nearly 40 years ago. Since that time, the technique has been refined in an effort to optimize acute outcomes while reducing the long-term need for reintervention and valve replacement. Balloon pulmonary valvuloplasty is considered first-line therapy for pulmonary valve stenosis and generally results in successful relief of valvar obstruction. Larger balloon to annulus (BAR) diameter ratios can increase the risk for significant valvar regurgitation. However, the development of regurgitation resulting in right ventricular dilation and dysfunction necessitating pulmonary valve replacement is uncommon in long-term follow-up. Balloon aortic valvuloplasty has generally been the first-line therapy for aortic valve stenosis, although some contemporary studies have documented improved outcomes following surgical valvuloplasty in a subset of patients who achieve tri-leaflet valve morphology following surgical repair. Over time, progressive aortic regurgitation is common and frequently results in the need for aortic valve replacement. Neonates with critical aortic valve stenosis remain a particularly high-risk group. More contemporary data suggest that acutely achieving an aortic valve gradient <35 mm Hg with mild aortic regurgitation may improve long-term valve performance and reduce the need for valve replacement. Continued study will help to further improve outcomes and reduce the need for future reinterventions.     

Percutaneous balloon pulmonic valvuloplasty following treated endocarditis in a patient with congenital pulmonary valve stenosis

A 36-year-old woman with congenital pulmonary valve stenosis developed the rare complication of endocarditis of the valve. After successful sterilization of the valve, the patient underwent percutaneous balloon pulmonic valvuloplasty at a later date. The procedure successfully reduced the peak pulmonary valve gradient from 94 to 45 mm Hg. Percutaneous balloon valvuloplasty is the procedure of choice for treatment of congenital pulmonary valvular stenosis, even in the unusual patient who has healed endocarditis of the pulmonary valve.     

Electrocardiographic Changes Following Balloon Dilatation of Valvar Pulmonic Stenosis

The purpose of this paper was to study the electrocardiographic changes following balloon pulmonary valvuloplasty for pulmonic stenosis and to see if such changes reflect improvement in pulmonary valve gradient following balloon valvuloplasty. Forty-one patients, ages 7 days to 20 years, underwent balloon valvuloplasty for severe valvar pulmonic stenosis. In 35 of these patients ECGs were available 3 to 34 months (mean 11) following valvuloplasty and were compared with pre-valvu-loplasty electrocardiograms. In 30 children with excellent relief of pulmonic stenosis (group I), frontal plane mean QRS vector moved toward the left from 127 ±25° to 81 ±47°as did the horizontal plane mean QRS vector, 88 ± 36° to 27 ±51°. The amplitude of R wave in V_1, 19 ± 11.6 mm, and V₂, 19.7 ± 12.2 mm, decreased respectively to 9.5 ± 5.9 mm and 11.3 ±6.1 mm. S wave amplitude in V₅ and V₆ also decreased. The improvement in the electrocardiogram is associated with a decrease in pulmonary valve gradient from 95 ± 50 to 29 ± 23 mm Hg. In five children with significant residual pulmonary valve gradient (group II), the electrocardiograms did not show any significant change. Evaluation of the time course of ECG changes in group I revealed that recognizable electrocardiographic improvement was first observed at 6 months following successful balloon pulmonary valvuloplasty. Normal electrocardiogram suggests minimal residual pulmonary valve gradient while right ventricular hypertrophy suggests significant residual obstruction unless the electrocardiogram was recorded at or before six months following balloon valvuloplasty. These data suggest that electrocardiogram is a good indicator of improvement following balloon pulmonary valvuloplasty. (J. Interven Cardiol 1988:1:3)     

BALLOON DILATATION PULMONARY VALVULOPLASTY IN PULMONARY STENOSIS

Abstract Balloon valvuloplasty was used to treat congenital pulmonary valve stenosis in 13 patients, 11 with isolated pulmonary stenosis, one associated with complex univentricular heart and tricuspid atresia, and one associated with tetralogy of Fallot. A balloon catheter was introduced through the pulmonary valve over a guidewire positioned in the distal pulmonary artery and inflated for 15 seconds on two or three occasions to 3 to 5 atmospheres and rapidly deflated. Marked improvement in pressure gradients was achieved in eight of the 11 patients with isolated pulmonary valve stenosis and symptoms disappeared in the only patient in this group who was symptomatic. The two patients with complex congenital malformations improved clinically. The procedure was without complication and satisfactory results have been maintained from two to twelve months later. The procedure offers effective treatment. We believe that pulmonary balloon valvuloplasty should be the initial treatment for isolated severe and moderate pulmonary valve stenosis.     

Results of valvuloplasties with balloon catheter in children. Follow-up using pulsed Doppler. Experience with our first cases

Our series includes the first 19 consecutive patients with pulmonary valvar stenosis who underwent balloon valvuloplasty in our hospital. All of them have been evaluated by an echo-Doppler study at different follow-up times, and in 10 patients the study was also performed prior to the dilatation. The ages ranged between 0.4 and 10 years (mean 3.5 years; standard deviation [SD] 2.53 years). The prevalvuloplasty degree of pulmonic stenosis found at catheterization was quantified as severe in 8 cases (42.11%) with a right ventricular systolic pressure (RVSP) in excess of 90 mmHg, and moderate in 11 cases (57.89%) with an RVSP from 70 to 90 mmHg. Transvalvular gradients were registered between 38 and 110 mmHg (m: 69 mmHg and SD: 15 mmHg). According to catheterization data obtained at the time of valvuloplasty, the procedure was considered ineffective in 2 cases (10.52%), scarcely effective in four (21.05%), and successful in the remaining 13 cases (68.42%). Doppler follow-up was carried out between 1.6 and 31.9 months after valvuloplasty (mean 12.9 months and SD: 10 months). Residual stenoses were estimated by Doppler as mild in 13 cases (68.42%), moderate in four (21.05%) and severe in two (10.52%). Mild pulmonary regurgitation was detected in 10 patients (52%). The 13 patients with a satisfactory result had slight residual gradients at the valvular level that had not been modified with the course of time. Of the 4 cases with a poorly effective dilatation the gradients noted by Doppler increased in three of them, being valvular in all but one in whom the obstruction was catalogued as infundibular.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of propranolol for severe dynamic infundibular obstruction prior to balloon pulmonary valvuloplasty (a brief communication)

A case of severe pulmonary valvar stenosis and infundibular obstruction has been reported. Infundibular obstruction was so severe that no catheter could be advanced into the pulmonary artery. Propranolol, 0.5 mg given intravenously, reduced the obstruction and allowed the balloon dilatation of the pulmonary valve to be carried out without complication. Subsequently oral propranolol helped to remove the infundibular obstruction. We strongly recommend the use of propranolol when infundibular obstruction is present prior or after the balloon pulmonary valvuloplasty.     

Balloon pulmonary valvotomy – Not just a simple balloon dilatation

Balloon pulmonary valvotomy is the preferred mode of treatment in patients with isolated pulmonary valvar stenosis and has shown good long term results. It is generally considered a safe procedure with few complications. There have been however, case reports of potentially fatal acute severe pulmonary edema occurring after the procedure in some patients. The cause of this complication and its pathophysiology is still not clear. Its occurrence is also infrequent with less than 5 cases reported till now. We report a case of pulmonary valvar stenosis which developed acute severe refractory pulmonary edema immediately after balloon pulmonary valvotomy.     

Transcatheter management of cyanotic congenital heart defects: a review.

In this review, the role of transcatheter methods in the management of cyanotic congenital heart defects is discussed. In patients with interventricular right-to-left shunting secondary to pulmonary outflow tract obstruction (most commonly tetralogy of Fallot), balloon dilatation may be an effective palliative procedure in a substantial proportion of patients, obviating the need for a palliative shunt. We would recommend this if the patient's size or cardiac anatomy makes that patient an unsuitable candidate for safe total surgical correction. Infundibular myectomy with atherectomy catheter in tetralogy of Fallot patients may become a useful adjunct in the management of these infants. Cyanotic children with interatrial right-to-left shunt secondary to severe valvar pulmonary stenosis respond to balloon pulmonary valvuloplasty in a manner similar to that seen with isolated pulmonary valve stenosis. In these patients, balloon valvuloplasty is the treatment of choice and may be corrective in most cases. In patients with a narrowed Blalock-Taussig shunt, balloon angioplasty may improve pulmonary oligemia and systemic arterial hypoxemia and may obviate the need for a second systemic-to-pulmonary artery shunt. Balloon angioplasty is recommended if the patient's cardiac defect is not amenable to surgical correction at a low risk either because of the size of the patient or because of the complexity of the cyanotic heart defect. In patients with pulmonary valve atresia, initial opening of the atretic pulmonary valve by either laser or surgery with subsequent balloon dilatation is potentially beneficial in reducing the total number of surgical procedures that these children are likely to require. However, further clinical trials are needed prior to their general use.     

Indications and outcome of valvuloplasty

Balloon valvuloplasty is widely practiced, but its result depends on the pathology considered. Percutaneous mitral balloon valvuloplasty evolved from the earlier development of percutaneous balloon valvotomy of the pulmonic valve into an effective method for the treatment of patients with mitral stenosis. Percutaneous aortic balloon valvotomy has been used as an alternative to aortic valve replacement in elderly patients with degenerative calcific aortic stenosis, but immediate results are suboptimal and the short-term rate of restenosis is high. In congenital pulmonary valve stenosis, balloon valvotomy produces a dramatic relief of the pressure gradient with excellent long-term follow-up results.     

Results of balloon valvuloplasty in the treatment of congenital valvar pulmonary stenosis in children

Transluminal balloon valvuloplasty was used in the treatment of congenital valvar pulmonary stenosis in 19 children, aged 5 months to 18 years. The right ventricular (RV) systolic pressure and RV outflow tract gradient decreased significantly immediately after the procedure (95 +/- 29 vs 59 +/- 14 mm Hg, p less than 0.01, and 78 +/- 27 vs 38 +/- 13 mm Hg, p less than 0.01). Seven of these patients were evaluated at cardiac catheterization 1 year after balloon valvuloplasty. No significant change occurred in RV systolic pressure or RV outflow tract gradient at follow-up evaluation compared with measurements immediately after balloon valvuloplasty (60 +/- 5 mm Hg vs 56 +/- 12 mm Hg and 39 +/- 5 vs 38 +/- 10 mm Hg). In addition, follow-up evaluation was performed using noninvasive methods and included electrocardiography (n = 13), vectorcardiography (n = 11) and Doppler echocardiography (n = 11) Doppler echocardiography in 11 patients 15 +/- 9 months after balloon valvuloplasty showed a continued beneficial effect with a mild further decrease in RV outflow tract gradient. Thus, balloon valvuloplasty is effective in the relief of pulmonary stenosis.     

Percutaneous transluminal balloon valvuloplasty for pulmonary valve stenosis

Transluminal balloon valvuloplasty was used to treat congenital pulmonary valve stenosis in 20 patients. Follow-up cardiac catheterization was performed in 11 patients at intervals of from 2 to 12 months after the procedure. Peak systolic pressure gradient across the pulmonic valve decreased from 68 +/- 27 to 23 +/- 5 mm Hg (p less than .001) after valvuloplasty. There were no complications. Follow-up catheterization demonstrated persistent relief of right ventricular hypertension in the patients with typical pulmonary valve stenosis.     

Pulmonary regurgitation after percutaneous balloon valvoplasty for isolated pulmonary valvar stenosis in childhood

OBJECTIVES: A retrospective study was undertaken to determine the degree of pulmonary regurgitation following percutaneous balloon valvoplasty for isolated pulmonary valvar stenosis. BACKGROUND: Percutaneous balloon valvoplasty is the recognised treatment of choice in pulmonary valvar stenosis with effective relief of gradient. Few studies have reviewed the degree of pulmonary regurgitation after the balloon valvoplasty. METHODS: We reviewed all patients with isolated pulmonary valvar stenosis undergoing percutaneous balloon valvoplasty at a tertiary centre between December 1984 and August 1996. Those with an associated haemodynamically insignificant atrial septal defect or patent oval foramen were also included. Their medical records, echocardiograms and angiograms were studied. Colour flow Doppler was used as a semi-quantitative way of assessing the pulmonary incompetence. RESULTS: Over the period of review, 57 procedures had been performed in 49 patients. The median age at the time of the procedure was 1.08 years, with a range from 0.01 to 13.3 years. The median period of follow-up was 5.64 years, with a range from 3.00 to 14.26 years. Immediately following the dilation of the pulmonary valve, the peak-to-peak instantaneous systolic pressure gradient was significantly reduced. Seven patients required a second dilation of the valve. Their median age at the first valvoplasty, at 0.49 year, was significantly lower than those who required only one procedure, at a median of 1.50 years. Following the valvoplasty, mild pulmonary incompetence was noted in 26 out of 42 patients the day after the procedure, but only 7% had moderate incompetence. On follow-up, there was an increase in the number of patients with moderate to severe pulmonary incompetence, from 7% to 29%. Those patients in whom the procedure was performed at a younger age had more significant pulmonary incompetence. Neither the initial gradient across the pulmonary valve, nor the size of the balloon used, were related with statistical significance to the subsequent development of pulmonary incompetence. CONCLUSIONS: The majority of the patients with congenital isolated pulmonary valvar stenosis had only a mild increase in the degree of pulmonary incompetence following a single pulmonary valvoplasty. Patients who required the procedure early in life were more likely to develop significant pulmonary incompetence. The ratio of the size of the balloon to the diameter of the valve did not significantly affect the outcome. We suggest that those patients who had more severe stenosis because of a more abnormal pulmonary valve, and hence required early intervention, were more likely to develop greater pulmonary incompetence after the valvoplasty.     

Long-term follow-up results after balloon dilatation of pulmonic stenosis, aortic stenosis, and coarctation of the aorta: A review

Although immediate and intermediate-term results after balloon dilatation of congenital stenotic lesions of the heart in children are well studied, long-term results have not been documented. Therefore, we reviewed our experience along with the limited published data to address this issue. Late follow-up after balloon pulmonary and aortic valvuloplasty shows low-residual gradients, reintervention-free rates in the mid-80s for pulmonic and in the mid-50s for aortic stenosis, and an increase in degree and prevalence of similunar valve insufficiency. Balloon angioplasty of aortic coarctation results in low-residual gradients, residual hypertension in a minority of patients, low prevalence of aneurysms, and high rates of recurrence in the neonate and young infant. Overall, balloon dilatation is a useful technique in relieving congenital obstructive lesions of the heart in the pediatric patient, but continued study of (1) late pulmonary and aortic insufficiency after valvuloplasty, (2) recurrence and aneurysms after balloon angioplasty of coarctations and, (3) femoral artery compromise in lesions requiring transfemoral artery approach is warranted.     

Congenital valvar aortic stenosis

Opinion statement Congenital aortic stenosis is characterized by narrowing of the aortic valve orifice, leading to left ventricular hypertrophy and predisposing the patient to exercise intolerance and myocardial dysfunction. Careful monitoring is essential because of the progressive nature of this lesion. Balloon valvuloplasty is the procedure of choice as intermediate palliation for moderate to severe aortic stenosis. If balloon valvuloplasty is contraindicated, surgical valvotomy has a limited role in initial therapy. If balloon valvuloplasty is unsuccessful or contraindicated because of aortic insufficiency, the Ross operation (removal of the stenotic aortic valve and placement of a pulmonary autograft in the aortic position and a pulmonary homograft in the pulmonary position) is the treatment of choice.