Balloon dilatation with or without stenting for pulmonary artery or non-valvar right ventricular outflow tract obstruction in children

# Guidance
Current evidence on the safety and efficacy of balloon dilatation with or without stenting for pulmonary artery or non-valvar right ventricular outflow tract obstruction in children appears adequate to support the use of this procedure, provided that the normal arrangements are in place for consent, audit and clinical governance.
The procedure should only be undertaken in specialist paediatric cardiology units.
The Department of Health runs the UK Central Cardiac Audit Database (UKCCAD) and clinicians are encouraged to enter all patients into this database.# The procedure

# Indications
The right ventricular outflow tract includes the pulmonary valve and the tissue above and below it. Narrowing (stenosis) of this region may involve the area below the valve (subvalvar), the valve itself (valvar), or the area above the valve (supravalvar). Balloon dilatation of valvar right ventricular outflow tract narrowing (pulmonary valve stenosis) is covered in separate guidance.
Congenital subvalvar and supravalvar right ventricular outflow tract stenosis usually occurs with other cardiac defects, such as ventricular septal defect or tetralogy of Fallot. Postoperative right ventricular outflow tract obstruction may occur after surgery to create a conduit between the right ventricle and pulmonary artery in children with congenital anomalies. Narrowing may also occur beyond the right ventricular outflow tract, in one of the pulmonary arteries, or in their branches.
Standard treatment of non-valvar right ventricular outflow tract or pulmonary artery obstruction involves open chest surgery.

# Outline of the procedure
Balloon dilatation is a minimally invasive procedure that involves inserting a catheter into a large blood vessel, usually in the groin, and passing it up to the area of narrowing under radiological guidance. A balloon is then inflated within the narrowing to dilate the obstruction. Stenting involves the insertion of a small tube into the narrow region following balloon dilatation, to maintain patency.

# Efficacy
No comparative studies were identified. Reports of technical success rates (defined as > 50% increase in pre-dilatation diameter, > 50% decrease in pressure gradient or > 20% decrease in right ventricular to aortic peak pressure ratio) were 97% (77/79) for stent insertion and 60% (97/162) for balloon dilatation in one study, and 53% (39/74) for balloon dilatation in another study. For more details, refer to the Sources of evidence section.
The Specialist Advisors had no concerns regarding the efficacy of this procedure.

# Safety
One of the studies reported a 3% (5/162) complication rate for patients undergoing balloon dilatation. This included one femoral vein thrombosis, three pulmonary artery major dissections, and one transient pulmonary oedema. One study of stent implantation reported a complication rate of 1% (1/79  a pleural perforation with haemopericardium). For more details, refer to the Sources of evidence section.
The Specialist Advisors listed potential complications as arrhythmia, haemorrhage, stent migration, embolisation, balloon rupture, blood vessel damage and tricuspid valve damage.

# Other comments
Fewer data were available on the use of the technique for non-valvar right ventricular outflow tract obstruction than for pulmonary artery or branch pulmonary artery obstruction.
Andrew DillonChief ExecutiveJuly 2004# Further information

# Sources of evidence
The evidence considered by the Interventional Procedures Advisory Committee is described in the following document.
'Interventional procedure overview of balloon dilation with or without stenting for pulmonary artery or right ventricular outflow tract obstruction', April 2003.

# Information for patients
NICE has produced information on this procedure for patients and carers ('Understanding NICE guidance'). It explains the nature of the procedure and the guidance issued by NICE, and has been written with patient consent in mind.# About this guidance
NICE interventional procedure guidance makes recommendations on the safety and efficacy of the procedure. It does not cover whether or not the NHS should fund a procedure. Funding decisions are taken by local NHS bodies after considering the clinical effectiveness of the procedure and whether it represents value for money for the NHS. It is for healthcare professionals and people using the NHS in England, Wales, Scotland and Northern Ireland, and is endorsed by Healthcare Improvement Scotland for implementation by NHSScotland.
This guidance was developed using the NICE interventional procedure guidance process.
We have produced a summary of this guidance for patients and carers. Information about the evidence it is based on is also available.
Changes since publication
May 2012: minor maintenance.
Your responsibility
This guidance represents the views of NICE and was arrived at after careful consideration of the available evidence. Healthcare professionals are expected to take it fully into account when exercising their clinical judgement. This guidance does not, however, override the individual responsibility of healthcare professionals to make appropriate decisions in the circumstances of the individual patient, in consultation with the patient and/or guardian or carer.
Implementation of this guidance is the responsibility of local commissioners and/or providers. Commissioners and providers are reminded that it is their responsibility to implement the guidance, in their local context, in light of their duties to avoid unlawful discrimination and to have regard to promoting equality of opportunity. Nothing in this guidance should be interpreted in a way which would be inconsistent with compliance with those duties.
Copyright
 National Institute for Health and Clinical Excellence 2004. All rights reserved. NICE copyright material can be downloaded for private research and study, and may be reproduced for educational and not-for-profit purposes. No reproduction by or for commercial organisations, or for commercial purposes, is allowed without the written permission of NICE.
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