The National Institute for Health and Clinical Excellence is examining endovascular closure of perimembranous ventricular septal defect 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 endovascular closure of perimembranous ventricular septal defect.

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 recommendations
• 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The Advisory Committee will then prepare draft guidance which will be the basis for the Institute’s guidance on the use of the procedure in the NHS in England, Wales and Scotland.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 Interventional Procedures Programme manual, which is available from the Institute’s website (www.nice.org.uk/ipprogrammemanual).

Closing date for comments: 28 February 2006

Target date for publication of guidance: May 2006

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 endovascular closure of perimembranous ventricular septal defect appears adequate to support the use of this procedure provided that the normal arrangements are in place for consent, audit and clinical governance.

Patient selection is important, especially in children and asymptomatic patients.

When performed on children, this procedure should only be undertaken in specialist paediatric cardiology units with on-site surgical facilities.

The Department of Health runs the UK Central Cardiac Audit Database (UKCCAD), and clinicians are encouraged to enter all patients undergoing endovascular closure of perimembranous ventricular septal defect onto this database (www.ccad.org.uk).

Publication of further long-term follow-up data would be useful.

A ventricular septal defect (VSD) is the persistence of one or more holes in the septum that separates the left and right ventricles. VSD is the most common congenital heart defect. The cause of a congenital VSD is unknown and the defect may occur in association with other congenital heart defects. The most common type of VSD is a p erimembranous (or membranous) VSD which is located in the membranous part of the septum close to the tricuspid and aortic valves. Muscular VSDs are less common and can be located anywhere in the muscular part of the ventricular septum.

A VSD allows blood to leak from the left ventricle through to the right ventricle, increasing the flow of blood to the lungs. This may have several consequences including congestive heart failure, pulmonary vascular obstructive disease (particularly from large defects) and an increase in the risk of infective endocarditis (particularly from small defects).

In adults, a VSD may be acquired as a complication of a heart attack or trauma. This guidance does not address the use of endovascular closure for this type of VSD.

Most VSDs in infants are small and cause no symptoms. They usually close spontaneously after birth. Infants with symptoms of congestive heart failure can be treated conservatively with medication. However, if the defect is large, surgical closure is usually recommended. Conventional surgery for VSD is performed through an incision in the front of the chest. Cardiopulmonary bypass is established, and the defect is usually closed with a patch or, occasionally, by direct suture if the defect is small.

Endovascular closure of a VSD involves introducing one guidewire into the femoral artery in the groin and another into the femoral or jugular vein to establish an arteriovenous wire loop. A delivery sheath is advanced over the wires across the defect, usually through the right heart system. Echocardiographic and fluoroscopic guidance are used to determine the size, position and number of defects and their relation to adjacent structures, and to assist in placing the occluder device. A balloon may be used to measure the stretched diameter of the defect. The occluder device is pushed through the delivery sheath and expanded in the defect to close it. Small residual shunts after the procedure often resolve as endothelial tissue grows over and around the device.

There is only one perimembranous (membranous, asymmetrical or eccentric) VSD occluder device currently available that is specifically designed for the closure of a perimembranous VSD. Devices designed for other types of defects have also been used, including muscular VSD occluder devices, umbrella devices and detachable steel coils.

In a large case series following 107 patients that had perimembranous or muscular VSDs and were implanted with VSD occluder devices (17 perimembranous and 90 muscular VSD occluders), successful implantation of the device was reported in 97% (104/107) of patients. Complete closure of the defect was achieved in 100% (104/104) of patients at 1–48 months’ follow-up.

In the largest case series of 186 patients in whom the perimembranous VSD occluder device was used, patients were divided into three groups: single defects without aneurysm; single defects with aneurysm; and multiple defects with aneurysm. Immediate closure rates in the three groups were 90%, 98% and 89%, and complete closure rates at 1-year follow-up were 100%, 98% and 89%, respectively.

In one case series using the double umbrella device, successful implantation was achieved in 86% (24/28) of patients with perimembranous VSDs. Complete closure of the defect was achieved in 67% (16/24) of patients immediately after the procedure and at a mean follow-up of 17 months. This figure includes one patient who was implanted with a detachable coil device after the umbrella device placement failed. For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors stated that some patients need surgical repair after failed device implantation. They noted a risk of residual shunting following successful device implantation: this risk is usually higher for defects with aneurysms, especially if the defects are fenestrated.

Misplacement of the device was reported in two case series, occurring in 0% (0/27) and 15% (2/13) of patients. In a case series using the perimembranous VSD occluder device, transient ventricular arrhythmias were reported in all patients (27/27).

Complications reported after the procedure using perimembranous and muscular VSD occluder devices included transient ventricular arrhythmias in 100% (27/27) of patients, left bundle branch block in 0% (0/13) to 4% (1/25), complete heart block in 0% (0/25) to 2% (2/107), aortic regurgitation in 0% (0/13) to 4% (1/25), tricuspid regurgitation in 0% (0/13) to 8% (2/25), tricuspid stenosis in 0% (0/25) to 1% (1/107), and device embolisation in 0% (0/107) to 8% (1/13). For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors stated that the risk of complications is potentially much greater in infants than in older patients. Complications involving the aortic valve, the tricuspid valve and the atrioventricular node may potentially arise during and after device implantation because of the close proximity of these structures to the membranous septum.

It was noted that some of the reported studies had used devices not specifically designed for this procedure.

The Institute has produced guidance on endovascular closure of atrial septal defect (www.nice.org.uk/IPG096).

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

Interventional procedure overview of endovascular closure of perimembranous ventricular septal defect, September 2005

Available from: www.nice.org.uk/IP286overview