Operative findings after percutaneous pulmonary balloon dilatation of the right ventricular outflow tract in tetralogy of Fallot

At what age should tetralogy of Fallot be corrected?

Tetralogy of Fallot can be corrected with very low mortality at any age, even in neonates, but this does not necessarily mean that it should be corrected in the neonatal period. Although there are many advantages to early correction, a high proportion of these neonates have residual stenosis or pulmonary regurgitation that impairs ventricular function and may require further surgery or implantation of a pulmonary valve. Before we had the ability to correct this anomaly with low mortality in small children, a variety of palliative procedures had to be performed. Today, with better understanding of the anatomy of tetralogy of Fallot, we should consider what forms of palliation will increase growth of the right ventricular outflow tract in order to reduce the complications of very early surgery.

Balloon pulmonary valvotomy as interim palliation for symptomatic young infants with tetralogy of Fallot

Objectives:

To describe the case selection, technique and immediate and short-term results of balloon pulmonary valvotomy (BPV) in young infants with tetralogy of Fallot (TOF).

Background:

Symptomatic young infants with TOF can either undergo corrective surgery or Blalock-Taussig (BT) shunt. Corrective surgery in early infancy is associated with significant morbidity and is not a realistic option in many centers. BT shunt carries the risk of branch pulmonary artery distortion and shunt occlusion.

Methods:

Infants less than three months with a significant valvar pulmonary stenosis (with or without associated infundibular and annular component) and oxygen saturation ≤80% were offered BPV. The right ventricular outflow tract (RVOT) was crossed with 4F Judkin's right coronary catheter and the valve was crossed with 0.014” coronary guide wire. Serial balloon dilatations were done with over the wire coronary balloons (3-4 mm) and Mini Tyshak balloons up to a balloon annulus ratio of 2:1, depending upon the improvement in saturation and formation of annular waist.

Results:

Seventeen infants less than three months of age with tetralogy of Fallot (median age: 33 days, range: 10-90 days, weight: 3.47 ± 0.87 kg, pulmonary annulus Z score: -5.59 ± 1.04) including eight neonates underwent palliative BPV between May 2004 and March 2007. The mean balloon annulus ratio was 1.4 ± 0.28 and fluoroscopy time was 26.18 ± 20.2 minutes. The mean oxygen saturation increased significantly from 73 ± 7% to 90 ± 3.68% following BPV (p = 0.0001). The only major complication was RVOT perforation and pericardial tamponade in one infant. The mean follow-up period was 23 ± 12 months. Two babies developed significant desaturation requiring surgery in the six months following BPV. There was a significant increase in pulmonary annulus. The z score for the pulmonary annulus improved from -5.59 ±1.04 before BPV to - 4.31 ± 1.9 at the time of last follow-up (p = 0.018). The mean Z score of hilar right pulmonary artery (RPA) increased significantly from -1.19 ± 1.78 before BPV to 0.7 ± 0.91 after BPV (p = 0.001). The mean Z score of hilar left pulmonary artery (LPA) increased significantly from -1.28 ± 1.41 to 0.03 ± 1.29 after BPV (p = 0.005). Eight patients underwent corrective surgery.

Conclusions:

Balloon pulmonary valvotomy is safe and effective. It significantly improves the growth of pulmonary annulus and branch pulmonary arteries. Thus it can be considered as an interim palliative procedure for symptomatic young infants with TOF and predominant valvar pulmonary stenosis.

Tetralogy of Fallot: Late outcome after repair and surgical implications

Cardiac surgery has transformed the outcome for patients with tetralogy of Fallot. Repair has conveyed excellent long-term results with most patients remaining well and leading normal lives. However, there are problems with late morbidity and mortality primarily due to right ventricular dysfunction, exercise intolerance, arrythmia, and sudden cardiac death. There has been a dynamic shift in our surgical approach to managing patients with tetralogy over the past 5 decades. This in part accounts for persisting difficulties in predicting late outcome for evry single patient with repaired tetralogy of Fallot. There are, however, several confounding variables, influencing long-term outcome for these patients, namely the underlying anatomical substrate, age at repair, surgical approach to repair, and residual hemodynamic abnormalities. It is gratifying to see that recent knowledge accumulated from long-term follow-up studies is influencing contemporary surgical practice. Individualized strategies aiming to minimize the potential for free pulmonary regurgitation, and the long-term detrimental effects associated with it, need to continue to develop. Preservation of right ventricular and pulmonary valve function combined with early restoration of normal pulmonary blood flow are likely to convey an even better long-term outlook for these patients. Further follow-up studies with assessment of bi-venticular function, however, are needed in both our older and contemporary cohorts with repaired tetralogy of Fallot. Copyright 2000 by W.B. Saunders Company

[Guidelines of clinical practice of the Spanish Society of Cardiology. Requirements and equipment of invasive techniques in pediatric cardiology: clinical application]

Invasive techniques in pediatric cardiology have experienced a big change since the 80's. The growth of non-invasive methods for diagnosing congenital heart defects has made the number of diagnostic catheterizations decrease remarkably. On the other hand, the notable development of pediatric interventional catheterization techniques will allow that, in the near future, the number of therapeutic catheterizations overcomes the diagnostic ones in our country. The former are more difficult and dangerous, so they require experienced and skilled hands and more economic resources. This chapter is divided in three main sections: I) Requirements and equipment needed for pediatric invasive techniques; II) Current indications, contraindications and complications of the diagnostic catheterization, and III) Techniques, indications and results of pediatric therapeutic catheterization: current state. Likewise, we state the suitability or not for these therapeutic procedures in different cardiac anomalies.

Balloon valvoplasty in infants with tetralogy of Fallot: effects on oxygen saturation and growth of the pulmonary arteries

Balloon valvoplasty was undertaken in 27 patients with tetralogy of Fallot for first-stage palliation. Indications were arterial saturation of oxygen < 80%, hypoxic spells and duct-dependant pulmonary perfusion. The dilation was performed following diagnostic heart catheterization. Saturations improved from 75% +/- 8.5 before valvoplasty to 85% +/- 8.4 after the procedure, and worsened little to 83% +/- 9.6 at follow-up after 3.4 months. The pulmonary valvar orifice was hypoplastic in most patients (Z = -3.3 +/- 1.2), and did not change after the procedure. The cross-sectional area of the pulmonary arteries was diminished initially, reflected by a Nakata index of 186 +/- 95 mm2/m2. After valvoplasty, we found widening of the vessels (Nakata index 225 +/- 100 mm2/m2). At follow-up no further growth of the arteries was observed (Nakata index 209 +/- 109 mm2/m2). The procedure was complicated by hypoxic spells in three patients which were controlled by intravenous propranolol, and deep venous thrombosis in four patients. Our data demonstrate that balloon valvoplasty is feasible for initial palliation in patients with tetralogy of Fallot. It does not, however, produce growth of the pulmonary arteries or of the pulmonary valve.

Palliative balloon valvoplasty of the pulmonary valve in tetralogy of Fallot

Balloon dilation of the pulmonary valve was performed in 54 patients with tetralogy of Fallot with severe cyanosis, high haematocrit and severe valvar pulmonary stenosis. Clinical, echocardiographic, angiographic, and haemodynamic data were analyzed before and after the procedure. After balloon dilation, the systemic oxygen saturation increased from a mean value of 66% to 85%. The mean value of the haematocrit before dilation was 55 + 13, and decreased to 47 after dilation (p < 0.002) in 2 months follow-up. Balloon dilation increased the size of the pulmonary valvar orifice from a mean value of 9 + 5 mm to 11.5 + 2 mm (p < 0.005). The mean Z score of the pulmonary valves, which was -3 + 1.3 before dilation, increased to -1.1 + 1.1 immediately after the procedure (p < 0.05). The size of the right and left pulmonary arteries increased after dilation from 9 mm to 10 mm, and from 8.7 + 2.4 mm to 9.8 + 2.3 mm, respectively (p < 0.05). The comparable mean Z scores increased from -2.8 + 1.9 SD to -1.8 + 1.4 SD, and from -2.4 + 1.9 SD to -1.5 + 1.6 SD for the right and left branches, respectively (p < 0.05). In patients with stenosis at the bifurcation of the pulmonary trunk and hypoplasia of the left artery, successful dilation of the pulmonary valve lead to an increase of flow and improvement in size of the hypoplastic segment. In conclusion, initial balloon dilation of the pulmonary valve in tetralogy of Fallot resulted in increase of the Z score for the pulmonary valve and improved antegrade pulmonary blood flow, inducing growth of the pulmonary arteries and ameliorating the anatomic and physiologic preoperative condition.

The role of catheter-directed therapies in the treatment of congenital heart disease

Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart defects. These procedures may be broadly grouped as dilations (valvuloplasty, angioplasty, and endovascular stenting) or as closures (vascular embolizations and device closure of defects). Balloon valvuloplasty has become the treatment of choice for simple valvar pulmonic stenosis in all age groups and, although not curative, appears at least comparable to surgery for noncalcific aortic stenosis in newborns through young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although still investigational, devices have been successfully used for closure of large numbers of atrial and ventricular septal defects. In this review, the current role of each major catheter intervention is discussed and results are compared with alternative forms of therapy. Catheter-based therapeutics are then placed in context in a discussion of combined catheter-surgical treatment of patients with complex congenital heart defects.

Balloon pulmonary valvuloplasty for double outlet right ventricle with valvular pulmonary stenosis

A male neonate presented with cyanosis. Echocardiograms showed a double outlet right ventricle, an absent outlet septum, a subaortic ventricular septal defect and valvular pulmonary stenosis. Balloon pulmonary valvuloplasty was performed at 19 days of age, resulting in an immediate increase of the systemic arterial oxygen saturation from 67 to 87%. As far as could be found, this is the first report of a patient with a double outlet right ventricle without the outlet septum who was clinically observed and underwent balloon pulmonary valvuloplasty.

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.

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.

Balloon pulmonary valvuloplasty in the management of cyanotic congenital heart defects

Twenty-three children with cyanotic congenital heart defects, aged 3 days to 11.5 years, weighing 2.9 to 30 kg, underwent percutaneous balloon pulmonary valvuloplasty to improve pulmonary oligemia. The patients were divided into two groups: group I with intact ventricular septum and group II with ventricular septal defect. In 12 group I patients, there was an increase of systemic arterial oxygen saturation [83 +/- 8% (mean +/- SD) vs. 94 +/- 5%, P less than 0.001] and pulmonary-to-systemic flow ratio (0.7 +/- 0.1 vs. 1.0 +/- 0.2, P less than 0.001). Peak systolic pressure gradient across the pulmonary valve decreased (P less than 0.001) from 105 +/- 48 to 25 +/- 18 mm Hg. In 11 group II patients, arterial oxygen saturation (67 +/- 13 vs. 83 +/- 13%, P less than 0.01) and pulmonary-to-systemic flow ratio (0.7 +/- 0.4 vs. 1.2 +/- 0.5, P less than 0.02) increased following valvuloplasty. Peak systolic pressure gradient across the pulmonic valve (52 +/- 16 vs. 32 +/- 22 mm Hg, P less than 0.05) decreased while infundibular and total pulmonary outflow tract gradients were unchanged (P greater than 0.1). Immediate surgical intervention was avoided in all cases in both groups. On follow-up, 1 to 36 months after valvuloplasty, arterial oxygen saturation, pulmonary-to-systemic flow ratio, and pulmonary valve gradients remain improved in both groups. However, in group I, repeat balloon valvuloplasty was required in two children. In group II, six children with tetralogy of Fallot (TOF) underwent successful total surgical correction 4 months to 2 years after valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of balloon pulmonary valvuloplasty as a palliative procedure in tetralogy of Fallot

Balloon pulmonary valvuloplasty was attempted in 67 patients with tetralogy of Fallot at a median age of 5 months (range 0.03 to 52 months) for relief of cyanosis. In three patients, the valve could not be crossed and an aortopulmonary shunt was performed. In 35 patients, follow-up angiography was performed 3 to 30 months (average 12) after valvuloplasty. In 24 of these 35 patients (group A), the stenosis had been adequately palliated by valvuloplasty; the other 11 patients (group B) had required an aortopulmonary shunt 1 month (range 0 to 3 months) after valvuloplasty. The two groups were similar (p greater than 0.1) with respect to age at valvuloplasty, pulmonary anulus diameter, ratio of pulmonary artery to descending aorta diameter before valvuloplasty and interval to follow-up angiography. In contrast to patients in group B, patients in group A had a significant immediate improvement in systemic arterial oxygen saturation (p less than 0.01) and a significant increase in pulmonary anulus diameter at follow-up angiography (p less than 0.001). The growth of the branch pulmonary arteries was similar (p greater than 0.1) in the two groups. Among 42 patients who have had surgical correction, a transannular patch for right ventricular outflow tract reconstruction was used in 27 (64%); there was no difference between groups A and B with respect to its use. Eight patients died (three after repair) and death could not be directly attributed to valvuloplasty in any. Balloon valvuloplasty promotes growth of the pulmonary valve anulus and pulmonary arteries and is a useful alternative to an aortopulmonary shunt in patients with small pulmonary arteries or associated complex intracardiac defects.