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

Effect of Balloon Pulmonary Valvuloplasty on Growth of Pulmonary Annulus in Infants with Tetralogy of Fallot

Percutaneous balloon pulmonary valvuloplasty (PBPV) is an alternative intervention in infants with Tetralogy of Fallot (TOF). It can not only improve hypoxia but also promote pulmonary annulus (PA) growth. In this study, we evaluated the effect of PBPV on PA growth in infants with TOF. To eliminate the effect of the systemic to pulmonary shunt (SPS) that may promote PA growth, we divided TOF infants into 2 groups: group A, patients who underwent PBPV with or without other SPS, and group B, patients who attempted SPS but without PBPV. Sixty patients were included, 28 patients in group A and 32 patients in group B. Age at the time of intervention in group A (range, 0.4-5.4; median 1.4 months) was lower than that in group B (range, 2.3-7.7; median 4.8 months), p-value 0.02. The body weight in group A (range, 3-5.5; median 3.7 kg) was also lower than that in group B (range 4.1-6.4; median 5.9 kg), p-value 0.02. Echocardiographic data at the mean follow-up period of 37.2 months (3-88 months) in group A and 39.6 months (6-95 months) in group B demonstrated an increase in mean PA diameter from 5.0 ± 1.3 mm to 10.2 ± 2.9 mm, p-value < 0.001 in group A; and from 6.2 ± 2 mm to 9.5 ± 2.9 mm, p-value < 0.001 in group B. The median PA z-score increased from - 3.4SD (- 3.9 to - 2.6SD) to - 1.8SD (- 2.5 to - 0.8SD), with the p-value of 0.002 in group A; and increased from - 2.9SD (- 4.5 to - 1.3SD) to - 2.7SD (- 3.6 to - 1.4SD), with the p-value of 0.73 in group B. By using the PA z-score as the absolute value, there was a statistically significant increase in the PA z-score during follow-up in group A, but not in group B. Balloon pulmonary valvuloplasty in infants with TOF can facilitate the growth of the pulmonic annulus even after eliminating the effect of the systemic to pulmonary shunt.

Palliation Strategy to Achieve Complete Repair in Symptomatic Neonates with Tetralogy of Fallot

Neonates with symptomatic tetralogy of Fallot (sTOF) may undergo palliations with varying physiology, namely systemic to pulmonary artery connections (SPC) or right ventricular outflow tract interventions (RVOTI). A comparison of palliative strategies based on the physiology created is lacking. Consecutive sTOF neonates undergoing SPC or RVOTI from 2005-2017 were reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was survival with successful complete repair (CR) by 18 months. A variety of secondary outcomes were assessed including overall survival, hospitalization-related comorbidities, and interstage reinterventions. Propensity score adjustment was utilized to compare treatment strategies. The cohort included 252 SPC (surgical shunt = 226, ductus arteriosus stent = 26) and 68 RVOTI (balloon pulmonary valvuloplasty = 48, RVOT stent = 11, RVOT patch = 9) patients. Genetic syndrome (29 [42.6%] v 75 [29.8%], p = 0.04), weight < 2.5 kg (28 [41.2%] v 68 [27.0%], p = 0.023), bilateral pulmonary artery Z-score < - 2 (19 [28.0%] v 36 [14.3%], p = 0.008), and pre-intervention antegrade flow (48 [70.6%] v 104 [41.3%], p < 0.001) were more common in RVOTI. Significant center differences were noted (p < 0.001). Adjusted survival to CR by 18 months (HR = 0.87, 95% CI = 0.63-1.21, p = 0.41) and overall survival (HR = 2.08, 95% CI = 0.93-4.65, p = 0.074) were similar. RVOTI had increased interstage reintervention (HR = 2.15, 95% CI = 1.36-3.99, p = 0.001). Total anesthesia (243 [213, 277] v 328 [308, 351] minutes, p < 0.001) and cardiopulmonary bypass times (117 [103, 132] v 151 [143, 160] minutes, p < 0.001) favored RVOTI. In this multicenter comparison of physiologic palliation strategies for sTOF, survival to successful CR and overall survival were similar; however, reintervention burden was significantly higher in RVOTI.

Transcatheter Approaches to Palliation for Tetralogy of Fallot

To this day, controversy still exists regarding the optimal method to treat symptomatic neonates and infants with Tetralogy of Fallot (TOF). Symptomatic (severely cyanotic or ductal dependent) infants with TOF can undergo either a staged repair approach (consisting of initial palliation followed by complete repair) or primary repair. Traditionally, initial palliative procedures have been surgical, for example placement of a Blalock-Taussig-Thomas (BTT) shunt. Recent advances in technology have facilitated the introduction of catheter-based procedures as palliative techniques, for example, patent ductus arteriosus (PDA) stenting and right ventricular outflow tract (RVOT) stenting as more durable solutions than balloon pulmonary valvuloplasty (BPV). In this article, we discuss the rationale for these procedures, technical aspects of these procedures and outcomes data compared to traditional surgical procedures. Recent data have suggested that RVOT and PDA stenting procedures offer many advantages over traditional surgical palliative procedures as palliative methods in this patient population. This comes at a cost of increased reintervention burden, which may be considered part of the overall treatment strategy in smaller neonates and can be minimized with a focus on technical aspects and overall treatment strategies. Advanced surgical techniques are required at the eventual complete repair to negotiate removal of stent material and pulmonary artery reconstruction in some instances. Further adoption of catheter based palliative procedures for infants with symptomatic TOF has the potential to tip the outcomes towards favoring a staged approach, particularly in high-risk infants.

Palliative Balloon Pulmonary Valvotomy in Tetralogy of Fallot: Is There a Role in 2021?

The current treatment practice for Tetralogy of Fallot (TOF) is to undertake complete surgical repair between 6–9 months of age with excellent immediate and long-term results. In patients with increased cyanosis or frequent cyanotic spells, younger age of complete repair as early as 3 months is usually acceptable. Although neonatal TOF repair is reported with good immediate survival from a few centres, post-operative morbidity is significant, and the hospital stay is prolonged. Hence, in neonates and small term and preterm infants with severe cyanosis, palliative procedures such as modified Blalock-Taussig (BT) shunt, ductal stenting, right ventricular outflow tract (RVOT) stenting and balloon pulmonary valvotomy (BPV) have been reported. With the development of low-profile stents, an increasing clinician experience and more predictable outcome with both duct and RVOT stenting, these procedures have gained popularity as the preferred palliations for TOF at most centres. We reviewed the literature to analyse whether BPV for TOF palliation, a technique first reported three decades ago, still has a role in the present era of paediatric cardiac care. In this review, we have concluded that BPV has very specific indications in patients with TOF, with predominantly valvar pulmonary stenosis, and may be a preferred option over other palliative strategies in hypoxemic preterm or low-birth weight infants.

Balloon Angioplasty as a Modality to Treat Children with Pulmonary Stenosis Secondary to Complex Congenital Heart Diseases

BACKGROUND

Pulmonary stenosis is common in children with complex congenital heart diseases. Proper management of this problem, especially postoperatively, is still controversial. This study was designed to assess the rate and determinants of success or failure of balloon angioplasty for such lesions.

METHODS

Clinical and hemodynamic data from 40 pediatric patients (24 boys and 16 girls) with complex congenital heart diseases who underwent balloon angioplasty were reviewed retrospectively from January 2012 to December 2016. Patients were divided into four groups according to the site of stenosis, which included pulmonary valve stenosis (PVS), valved conduit stenosis, pulmonary artery stenosis (PAS), and supravalvular pulmonary stenosis (SVPS). Success rates were calculated according to defined criteria for initial success and favorable clinical impacts, and comparison between the successful subgroup and the unsuccessful subgroups was analyzed.

RESULTS

Grouped by the site of stenosis, initial success rates varied from 40.0% to 52.4% with the greatest success being seen in the PVS group, followed by the PAS group and SVPS group. In the PVS group and the PAS group, there was no statistical difference among age at dilation, postoperative interval, balloon/stenosis ratio, or pressure gradient predilation between the successful and the unsuccessful subgroups. Favorable clinical impacts included success rates of balloon angioplasty in the SVPS group, which was best (100%), followed by the PVS group (90.9%) and the PAS group (85.7%). There were a total of two transient complications (5.0%).

CONCLUSIONS

Balloon angioplasty was proven to be a safe and useful modality in children with complex congenital heart diseases and postoperative pulmonary stenosis, which should be the initial therapeutic modality in selected patients.

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.

Right Ventricular Outflow Tract Stenting in Tetralogy of Fallot Infants With Risk Factors for Early Primary Repair

Background—

Tetralogy of Fallot with cyanosis requiring surgical repair in early infancy reflects poor anatomy and is associated with more clinical instability and longer hospitalization than those who can be electively repaired later. We bridged symptomatic infants with risk factors for early primary repair by right ventricular outflow tract stenting (stent).

Methods and Results—

Four groups of tetralogy of Fallot with confluent central pulmonary arteries were studied: stent group (n=42), primary repair (aged <3 months) with pulmonary stenosis (early-PS group; n=44), primary repair (aged <3 months) with pulmonary atresia (early-PA group; n=49), and primary repair between 3 and 11 months of age (surg>3mo group; n=45). Stent patients had the smallest pulmonary arteries with a median (95% credible intervals) Nakata index (mm 2 /m 2 ) of 79 (66–85) compared with the early-PA 139 (129–154), early-PS 136 (121–153), and surg>3mo 167 (153–200) groups. Only stent infants required unifocalization of aortopulmonary collaterals (17%). Stent and early-PA infants had younger age and lower weight than early-PS infants. Stent infants had the most multiple comorbidities. Stenting allowed deferral of complete surgical repair to an age (6 months), weight (6.3 [5.8–7.0] kg), and Nakata index (147 [132–165]) similar to the low-risk surg>3mo group. The 3 early treatment groups had similar intensive care unit/hospital stays and high reintervention rates in the first 12 months after repair, compared with the surg>3mo group.

Conclusions—

Right ventricular outflow tract stenting of symptomatic tetralogy of Fallot with poor anatomy (small pulmonary arteries) and adverse factors (multiple comorbidities, low weight) relieves cyanosis and defers surgical repair. This allowed pulmonary arterial and somatic growth with clinical results comparable to early surgical repair in more favorable patients.

Radiofrequency applications in congenital heart disease

The relatively recent application of radiofrequency technologies in the treatment of congenital heart defects has provided a safe and effective alternative to conventional therapies in establishing endovascular patency for a variety of lesions. Radiofrequency, with typically used frequencies of approximately 500 kHz, does not cause pain and is unlikely to induce atrial or ventricular fibrillation. It can be used either to ablate (higher power (35-50 W); longer duration of application (90-120 sec); lower voltage (30-50 V)) or to perforate (lower power (5-10 W) shorter duration of application (1-5 sec), higher voltage (150-280 V)). In the past, perforating radiofrequency has been applied to establish right ventricular outflow tract patency in pulmonary atresia with intact septum and with ventricular septal defect. More recently radiofrequency has been shown to be effective at recanalizing central and peripheral vasculature and has also been applied in establishing percutaneous left heart access. A new radiofrequency catheter, dedicated to transseptal left atrial cannulation, has been demonstrated to be safe and effective in an animal model and is now ready for clinical trials.

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.

A case of pulmonary stenosis after a repair for tetralogy of Fallot treated with percutaneous pulmonary valvuloplasty using a triple-balloon technique

The patient was a 37-year-old female who had undergone a repair for tetralogy of Fallot (TOF) at the age of 4 years. Postoperative pulmonary stenosis remained, but she continued to be managed medically. Approximately 3 years ago, at the age of 34, she exhibited a worsening of fatigue and dyspnea during exertion (New York Heart Association III), and was therefore hospitalized for a detailed examination. In cardiac catheterization, a right ventricle to pulmonary artery peak-to-peak gradient of about 90 mmHg was observed. Since it appeared that medical treatment alone would not sufficiently control her heart failure, pulmonary valvuloplasty using a triple-balloon technique was performed for the pulmonary stenosis. The peak-to-peak gradient immediately after the procedure decreased to 13 mmHg. There were no indications of restenosis approximately 6 months after the procedure, and the symptoms of heart failure in her daily life improved thereafter.

Balloon dilation of the pulmonary valve in premature infants with tetralogy of Fallot

Infants with tetralogy of Fallot (ToF) presenting with desaturation may require augmentation of the pulmonary blood flow, usually in the form of a Blalock-Taussig shunt. Shunts may result in a preferential increase in blood flow to one lung. They also may be associated with significant morbidity and possibly mortality of premature infants. Balloon dilation of the pulmonary valve is reported to improve saturation in early infancy. This report describes two premature infants (weighing, respectively, 1.8 and 1.6 kg) with ToF and desaturation for whom balloon dilation of the pulmonary valve showed good results. Neither infant required palliative surgery. At this writing, one infant has already undergone complete repair.

Balloon Valvuloplasty as an Initial Palliation in the Treatment of Newborns and Young Infants with Severely Symptomatic Tetralogy of Fallot

BACKGROUND

Balloon valvuloplasty in infants with symptomatic tetralogy of Fallot (TOF) may increase the pulmonary flow and prompt the growth of pulmonary arteries.

METHOD

From 1994 to 2002, percutaneous transluminal balloon valvuloplasty (PTPV) was performed in 22 consecutive newborns and young infants (<3 months of age) with TOF. The indication included severe hypoxemia (systemic oxygen saturation below 75%, 10 cases) and repeated hypoxic spells (12 cases). The age at PTPV was 8-88 days (38 +/- 34, median 27) and the body weight 2-5 kg (3.45 +/- 1.15, median 3). A balloon catheter (4- 7 mm in diameter and 2 cm in length) was used to dilate the pulmonary valve.

RESULTS

No major procedure-related complications occurred. The systemic oxygen saturation increased significantly (14 +/- 9%). A subsequent palliative shunt operation was avoided in 12 patients (54.5%), but 10 still needed operation (median 11 days after the PTPV). The presence of recurrent hypoxic spells before PTPV was the most important indicator for PTPV failure (p = 0.02).

CONCLUSION

PTPV was safe and effective for symptomatic newborns and young infants with TOF, but a palliative shunt operation was still needed due to short effect, especially in those with recurrent spells before the dilation.

Interventional catheterization performed in the early postoperative period after congenital heart surgery in children

OBJECTIVES

The purpose of this study was to examine the safety and efficacy of interventional catheterization performed early after congenital heart surgery.

BACKGROUND

Transcatheter interventions performed in the early postoperative period are viewed as high risk. To date, there have been limited published data regarding these procedures.

METHODS

All catheterizations performed within six weeks after congenital heart surgery between August 1995 and January 2001 were retrospectively reviewed. A cardiac anesthesiologist, cardiac intensivist, cardiac surgeon, and operating room team were available for all cases. Interventional procedures were performed based on clinical indications, regardless of the time elapsed from surgery.

RESULTS

Sixty-two patients, median age four months (2 days to 11 years), weight 4.7 kg (2.3 to 45 kg), underwent 66 catheterizations on median postoperative day 9 (0 to 42 days). Thirty-five cases involved 50 interventional procedures. Nine patients required extracorporeal cardiopulmonary support. Success rates by procedure were: angioplasty, 100%; stent implantation, 87%; vascular/septal occlusion, 100%; and palliative pulmonary valvotomy, 75%. Complications included stent migration (one patient), cerebral vascular injury (one patient), and left pulmonary artery stenosis (one patient). Thirty procedures involved angioplasty or stent implantation, including 26 involving a recently created suture line. Suture disruption or trans-mural vascular tears were not observed. There was no procedural mortality. Thirty-day survival for patients undergoing intervention was 83%.

CONCLUSIONS

Transcatheter interventions can be successfully performed in the early postoperative period. These procedures can have a positive impact on patient outcome; however, they should be performed only by a pediatric interventional cardiologist supported by a multi-disciplinary team.

Tetralogy of Fallot

The optimal surgical approach and timing for patients with tetralogy of Fallot remain controversial. There are two options in current practice: a two-stage repair (an initial palliative aortopulmonary shunt at an early age followed by complete repair at an older age) or primary complete repair. There has been a trend towards primary repair at a young age, which can be attributed to advances in anesthetic and cardiac surgical techniques. Primary repair has several advantages. The correction can be done in one operation and shunt complications are avoided. Progressive right ventricular fibrosis, ventricular hypertrophy, and chronic hypoxia are avoided, which may reduce the incidence of late ventricular arrhythmias. However, surgical correction at a young age is associated with an increased incidence of transannular patching and consequent pulmonary regurgitation. Progressive pulmonary regurgitation is associated with late ventricular arrhythmias and sudden death. These consequences may be prevented by timely pulmonary valve replacement. Palliative procedures include an aortopulmonary shunt, balloon dilation of the right ventricular tract, and stent placement. Of these measures, the aortopulmonary shunt is preferred, as it results in a more predictable outcome. Complications associated with shunt placement include shunt occlusion, pulmonary artery distortion, and occasionally, volume overloading of the left ventricle and pulmonary circulation. Institutional and surgeon preferences exist for either surgical strategy, and ultimately are justifiable when they produce the best outcomes for the individual patient. The optimal surgical strategy has to be determined by large prospective randomized studies that compare the functional status of the pulmonary valve and the need for reoperation at long-term follow-up.

Recommendations of the British Paediatric Cardiac Association for therapeutic cardiac catheterisation in congenital cardiac disease

The aims of these recommendations are to improve the outcome for patients after, and to provide acceptable standards of practice of therapeutic cardiac catheterisation performed to treat congenital cardiac disease. The scope of the recommendations includes all interventional procedures, recognising that for some congenital malformations, surgical treatment is equally as effective as, or occasionally preferable to, interventional treatment. The limitations of the recommendations are that, at present, no data are available which compare the results of interventional treatment with surgery, and certainly none which evaluate the numbers and types of procedures that need to be performed for the maintenance of skills. Thus, there is a recognised need to collect comprehensive data with which these recommendations could be reviewed in the future, and re-written as evidence-based guidelines. Such a review will have to take into account the methods of collection of data, their effectiveness, and the latest developments in technology. The present recommendations should, therefore, be considered as consensus statements, and as describing accepted practice, which could be used as a basis for ensuring and improving the quality of future care.

[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.

Interventional cardiac catheterization

Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

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.

Balloon dilation of the right ventricular outflow tract in tetralogy of Fallot: a palliative procedure

Fifteen patients requiring palliation for tetralogy of Fallot were treated by balloon dilation because of hypercyanotic spells. The mean age at dilation was 1.9 +/- 0.7 years (range 0.5-3), and the mean weight 9.8 +/- 2.1 kg (range 6.0-13.5). Dilation of the outflow tract was combined with dilation of the left and/or right pulmonary arteries in 5 patients. Successful dilation was achieved in 12 patients (80%), but failed in 3 patients with hypoplastic pulmonary arteries. In one patient, the stenosis of the right pulmonary artery could not be dilated because of a very sharp angle at the site of the stenosis. Two of the 3 patients in whom the procedure failed died of severe cyanotic spells within 24 hours of the unsuccessful procedure. No major complications occurred during or after the procedure in the cases undergoing successful dilation. The arterial oxygen saturation increased significantly, from 71 +/- 5.7% to 89 +/- 3.9%, immediately after the procedure (p < 0.005). During a period of follow up of 6 +/- 3.7 months (range 1-13), the procedure was repeated on 3 occasions, and successfully accomplished in 2 of these. In conclusion, balloon dilation is a satisfactory palliative procedure for tetralogy of Fallot in those units in which total correction is not performed under 2 to 3 years of age.

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.

Tetralogy of Fallot with diminutive pulmonary arteries: preoperative pulmonary valve dilation and transcatheter rehabilitation of pulmonary arteries

OBJECTIVES

This study sought to determine the results of a novel transcatheter management approach in tetralogy of Fallot with diminutive pulmonary arteries.

BACKGROUND

Tetralogy of Fallot with diminutive pulmonary arteries and severe pulmonary stenosis is rare and resembles tetralogy of Fallot with pulmonary atresia: There is a high incidence of aortopulmonary collateral channels, arborization abnormalities, stenoses and need for multiple operations. Because a combined catheter-surgery approach facilitates repair in these patients, such an approach may benefit those with diminutive pulmonary arteries and pulmonary stenosis.

METHODS

Clinical, catheterization and surgical data were studied retrospectively for 10 such patients undergoing preoperative pulmonary valve balloon dilation, among other transcatheter interventions, from January 1989 to January 1995.

RESULTS

Initially, the Nakata index ranged from 20 to 98 mm2/m2 (mean 67 +/- 28 mm2/m2). The pulmonary valve was first balloon dilated (mean balloon/annulus 1.5 +/- 0.3), and the mean initial valve annulus Z score (-4.0 +/- 1) increased to -33 +/- 1.1 (p < 0.01) Other interventions included branch pulmonary artery balloon dilation (7 patients, 23 vessels) and coil embolization of aortopulmonary collateral channels (8 patients, 31 collateral channels). At preoperative follow-up catheterization, the mean pulmonary annulus Z score was -3.1 +/- 0.7, and the Nakata index increased to 143 +/- 84 mm2/m2 (p < 0.03). All patients underwent complete surgical repair successfully. At a mean follow-up period of 2.6 +/- 2 years, right ventricular pressure was < 70% systemic in all patients and < 50% systemic in seven.

CONCLUSIONS

In patients with tetralogy of Fallot, severe pulmonary stenosis and diminutive pulmonary arteries, initial pulmonary valve balloon dilation increases the annulus Z score and anterograde pulmonary blood flow and facilities simultaneous coiling of aortopulmonary collateral channels and access for branch pulmonary artery dilation, all of which results in pulmonary artery growth, simplifying surgical management.

Sympathetic activity in children undergoing balloon valvuloplasty of pulmonary stenosis

We studied the influence of balloon valvuloplasty on alpha- and beta-adrenoceptor densities, plasma catecholamine, and cAMP levels in children and infants with pulmonary stenosis before and 10 min after balloon dilatation, employing as controls children undergoing transcatheter occlusion of patent ductus arteriosus (PDA) with Qp/Qs ratio < 1.5. In the PDA group, the alpha-adrenoceptor density (Bmax) was 3.75 +/- 0.72 fmol/10(7) cells (n = 15) before occlusion and remained unchanged at 3.35 +/- 0.47 fmol 10 min thereafter. In the pulmonary stenosis patients (n = 31), the receptor density was 59% higher (p < 0.05) before, and decreased to PDA levels 10 min after, the procedure. The control beta-adrenoceptor density was 64.8 +/- 11.0 fmol/10(6) cells before, and 71.2 +/- 13.2 fmol 10 min after, occlusion. In the study group, the density was 23% lower (p < 0.07) and increased to the PDA levels 10 min after the dilatation. Compared with the PDA, pre- and postdilatation plasma norepinephrine levels were not significantly changed; epinephrine was slightly elevated before, but increased by 73% after, dilatation; dopamine was 80% (p < 0.05); and cAMP was 37% higher before, and remained elevated at 70 and 23% above the PDA values after, the procedure. Accordingly, alpha-adrenoceptor density is significantly elevated in children with pulmonary stenosis and decreases significantly immediately after balloon valvuloplasty. On the other hand, beta-adrenoceptor density is attenuated and increases toward normal levels after the procedure. The immediate reversal of the receptor levels after balloon valvuloplasty suggests that this procedure exerts acute effects on the sympathetic functional level in this disease.

Early balloon dilatation of the pulmonary valve in infants with tetralogy of Fallot. Risks and benefits

BACKGROUND

Balloon dilatation, an established treatment for pulmonary valve stenosis, remains a controversial procedure in tetralogy of Fallot.

METHODS AND RESULTS

Balloon dilatation of the pulmonary valve was performed in 19 infants with tetralogy of Fallot. Its effects on the severity of cyanosis, the growth of the pulmonary valve and pulmonary arteries, and the need for transannular patching were evaluated. Clinical, echographic, angiographic, hemodynamic, and operative data were analyzed. The procedure was safe in all, without significant complications. After balloon dilatation, systemic oxygen saturation increased from a mean value of 79% to 90%. This increase proved to be short-lasting in 4 patients, who required surgery before the age of 6 months. Balloon dilatation increased pulmonary annulus size in each case, from a mean value of 4.9 to 6.9 mm (P < .001). This gain in size remained stable over time, with a mean Z score of -4.8 SD before dilatation, -3.1 SD immediately after the procedure, and -2.7 SD at preoperative catheterization (P < .001). Pulmonary artery dimensions remained unchanged immediately after balloon dilatation but increased at follow-up from a Z score mean value of -2.5 to -0.06 SD and from -2.2 to 0.04 SD for right and left pulmonary arteries, respectively (P < .001). At the time of corrective surgery, the pulmonary annulus was considered large enough to avoid a transannular patch in 69% of the infants. This represented a 30% to 40% reduction in the need for a transannular patch compared with the incidence of transannular patch expected before balloon dilatation.

CONCLUSIONS

Pulmonary valve dilatation in infants with tetralogy of Fallot is a relatively safe procedure and appears to produce adequate palliation in most patients. It allowed the growth of the pulmonary annulus and of the pulmonary arteries, resulting in a mean gain of 2 SD for those structures.

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.

Management of typical and dysplastic pulmonic stenosis, uncomplicated or associated with complex intracardiac defects, in juveniles and adults: use of percutaneous balloon pulmonary valvuloplasty with eight-month hemodynamic follow-up

To alleviate large fixed right ventricular (RV) outflow gradients, percutaneous balloon dilatation of pulmonic stenosis (PS) was performed in 38 patients with mean age of 14 +/- 14 years (median: 9 years, age range: 9 months to 63 years). There were 21 males and 17 females. Thirty-four patients had typical PS (5 of them also having other complex congenital cardiac anomalies, while 13 additional patients had a patent foramen ovale); 2 further subjects had subpulmonic, and 2 dysplastic pulmonary valvular obstructions. Sixteen patients were in the New York Heart Association (NYHA) Class I, 15 in Class II, 6 in Class III, and 1 in Class IV. Electrocardiographic (ECG) evidence of right ventricular hypertrophy (RVH) was present in 29 patients (76%); 3 patients had right bundle branch block (RBBB). For the entire group, there was a marked decrease in the mean systolic transpulmonic gradient in the immediate post-valvuloplasty period (from 97 +/- 43 to 26 +/- 17 mmHg; P < 0.0001). One patient expired 8 hours post-valvuloplasty (he was in the NYHA Class IV, and had severe RV failure). No other cardiovascular complications were encountered; the median hospital stay was 3 days (range: 1-10 days). At an 8-month follow-up, 12 patients who were reevaluated invasively had a median transpulmonic gradient of 27 mmHg (range: 5-92 mmHg) as compared to their pre-valvuloplasty values of 84 mmHg (range: 49-142 mmHg; P < 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Cavopulmonary connection in repair of atrioventricular septal defect with small right ventricle

Between February 1991 and May 1992, 9 patients with a nonrestrictive inlet ventricular septal defect or complete atrioventricular septal defect and hypoplasia of the right ventricle underwent successful two-ventricle correction incorporating a bidirectional cavopulmonary anastomosis. Despite a satisfactory early postoperative course, large serous pleural effusions developed in 5 of them between 2 and 6 weeks after operation. Serial echocardiography showed an evolution of flow patterns in the superior vena cava from marked systolic reversal immediately after operation to nearly continuous forward flow into both pulmonary arteries about 6 weeks later. This pattern was consistent with the transition from cardiac-dependent to respiratory-dependent caval flow. The development of pleural effusions appeared to coincide with the loss of systolic caval flow reversal and resolved after establishment of a predominantly respiratory-dependent flow pattern.