Interventional procedure consultation document

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

Adjustable pulmonary artery banding is used in some young children born with heart defects. In this procedure, an adjustable metal band is clipped around the blood vessel that carries blood from the heart to the lungs to restrict blood flow and reduce pulmonary artery blood pressure. The aim is to reduce the risk of heart failure caused by high blood pressure in the lungs. The band can be adjusted at any time using a remote control (for example, as the child grows), without the need for further surgery.

 

The National Institute for Health and Care Excellence (NICE) is examining telemetric adjustable pulmonary artery banding for reducing pulmonary hypertension in infants with congenital heart defectsand will publish guidance on its safety and efficacy to the NHS. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of specialist advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about telemetric adjustable pulmonary artery banding for reducing pulmonary hypertension in infants with congenital heart defects.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website.

Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination, advance equality of opportunity, and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 2 September 2014

Target date for publication of guidance: November 2014

 

 

 

1                      Provisional recommendations

1.1                  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.

1.2                  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[URL to be added at publication] 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.

1.3                  Patient selection for telemetric adjustable pulmonary artery banding for pulmonary hypertension in infants with congenital heart defects should be done in paediatric cardiac centres, by a multidisciplinary team experienced in managing infants with congenital heart defects.

1.4                  Further research should focus on the extended use of telemetric adjustable pulmonary artery banding for ventricular retraining and for its use in the resolution of ventricular septal defects. Data collection may provide useful information. NICE may review the procedure on publication of further evidence.

 

 

 

 

 

2                      Indications and current treatments

2.1                  Congenital heart defects with a left-to-right shunt and excessive pulmonary blood flow can result in pulmonary overcirculation and congestive heart failure in the neonatal period. The usual treatment is surgical correction of any defect. The most common defects 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.

2.2                  Pulmonary artery banding (PAB) is a palliative procedure that is used as part of staged treatment before 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 left-to-right 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, nylon or Teflon) and sutures are used. In non-adjustable PAB methods, reoperation is often needed to adjust the tightness of the band.

 

 

 

 

3                      The procedure

3.1                  Telemetric adjustable pulmonary artery banding is mainly used in infants with multiple or single ventricular septal defects and those with left ventricular retraining for congenitally corrected transposition of the great arteries.

3.2                  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 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.

3.3                  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.

 

 

 

 

4                      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 [add URL].

4.1                  In a non-randomised comparative study of 40 infants who had pulmonary artery banding (20 with telemetric adjustable pulmonary artery banding [TA-PAB] and 20 with conventional pulmonary artery banding [con-PAB]), postoperative mechanical ventilation time was significantly shorter after TA-PAB than con-PAB (3.0+/-3.1 days versus 10.4+/-11.2 days, p<0.01), as was length of stay in the intensive care unit (5.3+/-4.6 versus 20.3+/-19.9 days, p<0.005) and in hospital (15.4+/-6.4 days versus 45.6+/-41.6 days, p<0.005).

4.2                  A non-randomised comparative study of 19 infants who had PAB (11 with TA-PAB and 8 with con-PAB) reported no differences between groups with respect to postoperative ventilation time (230±302 versus 109±174, p=0.3), or length of stay in the intensive care unit (11.2±12.9 versus 7.8±10.7, p=0.4) or in hospital (18±10 versus 17±9, p=0.9).

4.3                  In a case series of 17 children with multiple muscular apical ventricular septal defects, all infants had percutaneous adjustments of the TA-PAB, 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,

4.4                  In a non-randomised comparative study of 20 patients with complete atrioventricular septal defects (7 treated with TA-PAB and 13 with con-PAB), sternal closure was not delayed in any of the 7 infants in the TA-PAB group, compared with delayed closure in 46% (6/13) of infants in the conventional PAB group (p<0.05).

4.5                  In the non-randomised comparative study of 20 patients, left atrioventricular valve regurgitation decreased in 2 infants (from severe to moderate) in the TA-PAB group (n=7) and increased in 2 infants (from mild to moderate in 1 and moderate to severe in 1) in the conventional PAB group (n=13), and remained unchanged in all other infants in both groups.

4.6                  A non-randomised comparative study of 10 patients with late-referral transposition of the great arteries (4 treated with TA-PAB and 6 with con-PAB) reported that, in the TA-PAB group (n=4), the mean pulmonary gradient increased from 25.50±4.43 mmHg to 63.50±9.80 mmHg at the time of an arterial switch procedure (4 months after banding). In the conventional PAB group (n=6), the mean pulmonary gradient increased with growth from 49.20±21.40 mmHg to 68.40±7.86 mmHg. The difference in pressure increase between the groups was not significant.

4.7                  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.

 

 

 

 

5                      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 [add URL].

5.1                  A non-randomised comparative study of 40 infants (20 with telemetric adjustable pulmonary artery banding [TA-PAB] and 20 with conventional pulmonary artery banding [con-PAB]) reported that no patients died within 30 days in the TA-PAB group (n=20) and that 15% (3/20) died at 1, 15 and 20 days after surgery in the con-PAB group. These 3 deaths were caused by cardiac arrest during tracheal suctioning, inexorable heart failure and multi-organ failure. There were 2 (10%, 2/20) deaths after 30 days in the TA-PAB 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 con-PAB group, 1 caused by sepsis and 1 by heart failure.

5.2                  In a case report of a 6‑month‑old infant (weighing 6 kg) who had a closure for 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 TA-PAB . The residual VSD was closed transatrially with a polytetrafluoroethylene patch, the pseudoaneurysm cavity was resected and the pulmonary artery was reconstructed by an end-to-end anastomosis. Recovery was uneventful.

5.3                  Reoperation 8 days after TA-PAB was needed for drainage of a pericardial effusion was reported in 1 infant in a case series of 17 patients treated with TA-PAB for multiple VSDs. Reoperation to remove the TA-PAB because of hemodynamic compromise related to the bulk of the device was needed in 1 patient in the TA-PAB group (n=11) in a non-randomised comparative study of 19 patients who had PAB (11 with TA-PAB and 8 with con-PAB).

5.4                  Patch augmentation of the pulmonary artery at the time of corrective surgery was needed in 5 patients (4 in the TA-PAB group and 1 in the conventional PAB group) in the non-randomised comparative study of 19 patients. The course of recovery was similar in both groups.

5.5                  Persistent sepsis after TA-PAB developed in 3 patients in a case series of 8 patients. This was successfully treated with antibiotics in all 3 patients, without the need for surgical re-intervention or removal of the band.

5.6                  The specialist advisers listed additional adverse events as: device migration; device removal because of hemodynamic 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.

 

 

 

 

6                      Committee comments

6.1                  The Committee noted that conditions needing pulmonary artery banding are rare and large randomised studies would therefore be impractical. This consideration underpinned the recommendation for data collection as a way of providing information for review of the procedure.

6.2                  The Committee noted that the UK Central Cardiac Audit Database collects data on pulmonary artery banding but does not currently distinguish between the different kinds of pulmonary artery banding. It was advised that steps would be taken to enable data on telemetric adjustable banding to be recorded and identified.

 

 

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
June 2014

 

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