The National Institute for Clinical Excellence is examining balloon or blade atrial septostomy in neonates and will publish guidance on its safety and efficacy to the NHS in England, Wales and Scotland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about balloon or blade atrial septostomy in neonates.

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 preliminary recommendation
• the identification of factual inaccuracies
• additional relevant evidence.

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

The process that the Institute 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• The Advisory Committee will then prepare draft guidance, which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales and Scotland.

For further details, see the Interim Guide to the Interventional Procedures Programme, which is available from the Institute's website (www.nice.org.uk/ip).

Closing date for comments: 24 February 2004

Target date for publication of guidance: May 2004

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.

Current evidence on the safety and efficacy of balloon or blade atrial septostomy in neonates appears adequate to support the use of this procedure provided that the normal arrangements are in place for consent, audit and clinical governance.

The main indication for this procedure is transposition of the great vessels, an uncommon congenital cardiac anomaly in which the aorta arises from the right ventricle and the pulmonary trunk arises from the left ventricle. This results in two separate circuits of blood flow, in which highly oxygenated blood recycles through the lungs, while oxygen-depleted blood recycles around the body. As a result, the baby develops a blue colour (cyanosis) shortly after birth. The neonate can survive for a few days because the foramen ovale (a small hole in the foetal interatrial septum) allows some oxygenated blood to mix with the blood that is being recirculated around the body. However, the foramen ovale normally closes days after birth, and the only babies then likely to survive are those with a congenital ventricular septal defect.

There is no reliable alternative to septostomy procedures in neonates.

The aim of balloon or blade atrial septostomy is to enlarge the foramen ovale to allow oxygenated blood to pass into the right atrium and mix with the deoxygenated blood that is recirculating around the body. A catheter is passed through a large vein, usually in the groin, into the right atrium and through the foramen ovale to the left atrium. A balloon at the end of the catheter is inflated and pulled back into the right atrium, so enlarging the foramen ovale. If the inter-atrial septum is too thick or the foramen ovale too small, the operator may use a catheter with a blade at its end to cut the septum. Static balloon atrial septostomy is a variation of balloon atrial septostomy, which is usually used to enlarge the hole made in the interatrial wall during blade septostomy. This procedure aims to prolong survival until definitive surgery can be performed several months later.

No controlled studies were identified and many of the studies found were published more than 15 years ago. One of the studies reported an 'immediate haemodynamic effect' in 95% (508/535) of patients. Another reported a mean increase in arterial oxygen saturation of 21%; two other studies reported increases of 21% and 16% in median systemic arterial oxygen saturation. For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors noted that the septostomy may close spontaneously, necessitating surgical septectomy.

Among the identified studies, the death rate from the procedure ranged from 2% (2/104, 3/149) to 3% (3/108). One study reported an early death rate of 13% (19/149) and a late death rate of 17% (25/149), but the time-points at which these were measured were not specified. Another study reported a minor complication rate of 10% (26/248) and a lethal complication rate of 1% (3/248). For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors considered the main safety concerns to be death, transient arrhythmias and cardiac injuries.

This procedure has become established as a life-saving measure for severely ill neonates, and clinical trial data are very limited.

Transposition of the great arteries is usually diagnosed antenatally and affected infants are born in a specialist unit. Measures are now taken to prolong the patency of the ductus arteriosus and neonates are therefore better prepared for surgery.

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

• Interventional Procedure Overview of balloon or blade atrial septostomy in neonates, March 2003

Available from: www.nice.org.uk/ip156overview