Third-Generation Tissue Valves and Valve-in-Valve Technology

Cardiac tumours in children are well known, though this exact pathology is not very common. The echo gives us an idea, but I would suggest also doing an MRI and a CT to further delineate it. I would like the details of this patient sent to our institute so we can forward it to our paediatric cardiac surgeon, since paediatric cardiac surgery is a separate subspecialty from the adult cardiac surgery I practise, and we do have a dedicated paediatric cardiac surgical team. This child needs very close follow-up and further investigation.

Tetralogy of Fallot is one of the commonest surgical procedures, and the outcome depends on the exact anatomy delineated by a proper paediatric echo, but six years is not a very late stage — in India a lot of patients are operated on at this age or even older. The outcome of tetralogy repair even at 6 years is excellent, so this patient certainly needs surgical correction.

Myocardial bridging is not uncommon and is often seen on angiography. If it is asymptomatic, nothing needs to be done. If it is symptomatic, we normally do a stress thallium test — if positive, we recommend surgery; if negative, which is most of the time, only medical treatment is needed. If it is only myocardial bridging with no stenosis involved in other arteries (the circumflex or right coronary artery are normal), nothing needs to be done, but if the stress test is positive, surgery is recommended.

Tetralogy of Fallot is one of the commonest procedures in paediatric cardiac surgery, alongside ASD and VSD repair. It is a very commonly performed procedure with excellent outcomes — any paediatric cardiac centre does this routinely, and the clinical outcomes are excellent.

The patient should be referred for further evaluation at the appropriate time — not too early, but also not too late, because if it is too late the patient develops more comorbidities and the outcome may not be as good. For valve disease specifically, there are definite guidelines for mitral and aortic valve disease on when a patient should be referred for cardiac surgery; whether it can be done locally depends on whether it looks like a straightforward repair or replacement, or a more challenging one. The two important criteria are the patient's clinical symptoms — which functional class (1, 2, 3, or 4) — and the echo findings, which show the severity of stenosis or regurgitation, LV function, and pulmonary artery pressures. Together these decide whether the patient should be referred for surgical treatment, locally or elsewhere.

Third-generation tissue valves in use today include the Inspiris valve from Medtronic, the Myval valve from the Indian company Meril, the Perceval valve from the UK-based company Corcym, and the Intuity valve from Edwards.

Tissue valve degeneration is caused mainly by calcification of the valve tissue, so slowing calcification through anti-calcification treatment means the valve lasts longer before it needs to be replaced, which matters most for younger patients since tissue valves degenerate faster in younger patients than in older ones.

Valve-in-valve technology allows a new valve to be implanted inside an old, degenerated valve using a catheter, without repeat open heart surgery.

Edwards has developed fluoroscopically visible markers so doctors can see the size of a previously implanted valve during a future procedure, along with an expansion zone in the valve's sewing ring that allows a larger replacement valve to be used later. Abbott's Epic valve carries similar radiopaque markers in its leaflets and stent posts for the same purpose.