Telemetric adjustable pulmonary artery banding for pulmonary hypertension in infants with congenital heart defects

# Recommendations
The evidence on the efficacy of telemetric adjustable pulmonary artery banding shows that the procedure can provide adjustable reduction of pulmonary artery flow in infants with congenital heart defects, but there are uncertainties about which infants will derive benefit from the procedure. The evidence on safety is limited in quantity. Therefore the procedure should only be used with special arrangements for consent, audit or research and clinical governance.
Clinicians wishing to undertake telemetric adjustable pulmonary artery banding for pulmonary hypertension in infants with congenital heart defects should take the following actions.
Inform the clinical governance leads in their NHS trusts.
Ensure that parents and carers understand the uncertainty about the procedure's safety and efficacy and provide them with clear written information. In addition, the use of NICE's information for the public is recommended.
Enter details about all infants undergoing telemetric adjustable pulmonary artery banding for pulmonary hypertension associated with congenital heart defects onto the UK Central Cardiac Audit Database and review clinical outcomes locally.
Patient selection for telemetric adjustable pulmonary artery banding for pulmonary hypertension in infants with congenital heart defects should only be done in paediatric cardiac centres, by a multidisciplinary team experienced in managing infants and children with congenital heart defects.
Further research should focus on the extended use of telemetric adjustable pulmonary artery banding for ventricular retraining and for its use pending the resolution of ventricular septal defects. Data collection may provide useful information. NICE may review the procedure on publication of further evidence.# Indications and current treatments
Congenital heart defects with a lefttoright shunt and excessive pulmonary blood flow can result in pulmonary hypertension and congestive heart failure in the neonatal period. The usual treatment is surgical correction of any defect when the infant is big enough. The most common defects needing this type of treatment include functionally univentricular hearts, transposition of the great arteries, and atrioventricular or multiple septal defects. The symptoms include fatigue, dyspnoea, tachypnoea and failure to thrive. Infants may develop a condition of irreversible pulmonary hypertension because of hypertrophy of the pulmonary arterioles.
Pulmonary artery banding (PAB) is a palliative procedure that is used as part of staged treatment before definitive surgical correction of congenital heart defects. The aim of PAB is to reduce the diameter of the main pulmonary artery, decreasing blood flow and reducing pulmonary artery pressure. Improvement of systemic pressure, cardiac output and ventricular function can also be expected in patients with a large lefttoright shunt. Risks of the procedure include lowering of systemic oxygen saturation, ventricular hypertrophy, subaortic obstruction, and pulmonary branch and valve distortion. The conventional technique of PAB involves surgical placement of a (not telemetrically adjustable) band around the main pulmonary artery. Different techniques using a variety of materials (such as strips of polytetrafluoroethylene, polydioxanone or nylon) and sutures are used. In nonadjustable PAB methods, reoperation is often needed to adjust the tightness of the band.# The procedure
Telemetric adjustable pulmonary artery banding is mainly used in infants with multiple or single ventricular septal defects and those needing left ventricular retraining for congenitally corrected transposition of the great arteries.
The procedure is done with the infant under general anaesthesia, either through a median sternotomy or lateral thoracotomy depending on the child's anatomy and the nature of their disease. The pericardium is opened over the great vessels and, with minimal dissection, a tunnel is created between the ascending aorta and the main pulmonary artery. The adjustable pulmonary artery band (which contains a micro motor) is fastened around the main pulmonary artery. The band is sutured to the pulmonary artery to prevent it from migrating. Coupling between the band and an external remote control unit (powered by an external antenna) is tested and the incision is closed.
Immediately after surgery, the infant is treated in a neonatal intensive care unit and the band is adjusted wirelessly by the control unit, according to the child's haemodynamic status, to control pulmonary artery flow. Echocardiography is used to gauge the adjustment needed. Later adjustments to the band can be done in an outpatient setting, without the need for further surgery. The band is removed at the same time as cardiac surgery for definitive repair of any heart defects.# Efficacy
This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.
In a nonrandomised comparative study of 40 infants who had pulmonary artery banding (20 with telemetric adjustable pulmonary artery banding  and 20 with conventional pulmonary artery banding ), postoperative mechanical ventilation time was significantly shorter after TAPAB than conPAB (3.0 plus or minus  -3.1 days versus 10.411.2 days, p<0.01), as was length of stay in the intensive care unit (5.34.6 days versus 20.319.9 days, p<0.005) and in hospital (15.46.4 days versus 45.641.6 days, p<0.005).
A nonrandomised comparative study of 19 infants who had PAB (11 with TAPAB and 8 with conPAB) reported no differences between groups with respect to postoperative ventilation time (230302 hours versus 109174 hours, p=0.3), or length of stay in the intensive care unit (11.212.9 days versus 7.810.7 days, p=0.4) or in hospital (1810 days versus 179 days, p=0.9).
In a case series of 17 infants with multiple muscular apical ventricular septal defects, all infants had percutaneous adjustments of the TAPAB, with a mean of 4.8 adjustments per patient (range from 2 to 9 times) to tighten the band and a mean of 1.1 adjustments per patient (range from 0 to 3 times) to loosen the band with the patient's growth. All adjustments were guided by doppler echocardiography.
In a nonrandomised comparative study of 20 infants with complete atrioventricular septal defects (7 treated with TAPAB and 13 with conPAB), sternal closure was not delayed in any of the 7 infants in the TAPAB group, compared with delayed closure in 46% (6/13) of infants in the conPAB group (p<0.05).
In the nonrandomised comparative study of 20 infants, left atrioventricular valve regurgitation decreased in 2 infants (from severe to moderate) in the TAPAB group (n=7) and increased in 2 infants (from mild to moderate in 1 and moderate to severe in 1) in the conPAB group (n=13), and remained unchanged in all other infants in both groups.
A nonrandomised comparative study of 10 infants with latereferral transposition of the great arteries who underwent retraining of the left ventricle (4 with TAPAB and 6 with conPAB) reported that the mean pulmonary gradient across the banding increased in the TAPAB group, with progressive closure from 25.504.43 mmHg at the time of placement to 63.509.80 mmHg at the time of an arterial switch procedure (4 months after banding). In the conPAB group, the mean pulmonary gradient increased with growth from 49.2021.40 mmHg at the time of placement to 68.407.86 mmHg at the time of the arterial switch procedure (4 months after banding). The difference in gradient at the time of the switch procedure was not statistically significant between the 2 groups. The authors state that the difference between the groups at baseline was due to the TAPAB not being tightened in the operating room. The pulmonary gradient at final follow up (19.7817.7 months) was similar in both groups (133.4 mmHg in the TAPAB group and 14.510.34 mmHg in the conPAB group, p value not given).
The specialist advisers listed additional key efficacy outcomes as control of hypertension in children with high pulmonary blood flow, retraining of a low pressure ventricle and survival to corrective surgery.# Safety
This section describes safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.
A nonrandomised comparative study of 40 infants (20 with telemetric adjustable pulmonary artery banding  and 20 with conventional pulmonary artery banding ) reported that no infants died within 30 days in the TAPAB group and that 15% (3/20) of infants died at 1, 15 and 20 days after surgery in the conPAB group. These 3 deaths were caused by cardiac arrest during tracheal suctioning, inexorable heart failure and multiorgan failure. There were 2 (10%, 2/20) deaths after 30 days in the TAPAB group, 1 attributed to respiratory infection and 1 to neurological damage (2 and 3 months after surgery respectively), and 2 (12%, 2/17) deaths in the conPAB group, 1 caused by sepsis and 1 by heart failure.
In a case report of a 6monthold infant (weighing 6 kg) who had a closure of an inlet muscular ventricular septal defect (VSD), complete erosion by the band causing a large pseudoaneurysm of the main pulmonary artery (with the device floating freely inside the pseudoaneurysm cavity and a significant residual ventricular septal defect) was reported 9 weeks after TAPAB. The residual VSD was closed transatrially with a polytetrafluoroethylene patch, the pseudoaneurysm cavity was resected and the pulmonary artery was reconstructed by an endtoend anastomosis. Recovery was uneventful.
Reoperation 8 days after TAPAB for drainage of a pericardial effusion was reported in 1 infant in a case series of 17 infants treated with TAPAB for multiple VSDs. Reoperation to remove the TAPAB because of haemodynamic compromise related to the bulk of the device was needed in 1 infant in the TAPAB group in a nonrandomised comparative study of 19 infants who had PAB (11 with TAPAB and 8 with conPAB).
Patch augmentation of the pulmonary artery at the time of corrective surgery was needed in 5 infants (4 in the TAPAB group and 1 in the conPAB group) in the nonrandomised comparative study of 19 infants. The course of recovery was similar in both groups.
Persistent sepsis after TAPAB developed in 3 infants in a case series of 8 infants. This was successfully treated with antibiotics in all 3 infants, without the need for surgical reintervention or removal of the band.
The specialist advisers listed additional adverse events as: device migration; device removal because of haemodynamic instability; the device losing coupling so it could not be telemetrically adjusted; failure of the band control unit; inability of the band to dilate; pulmonary valve regurgitation; and cardiac compression.# Further information
For related NICE guidance, see the NICE website.

# Information for patients
NICE has produced information on this procedure for patients and carers. It explains the nature of the procedure and the guidance issued by NICE, and has been written with patient consent in mind.
ISBN 978-1-4731-0843-1