Try filling a good wine with a stopper with a smaller diameter than the neck of the bottle. Whenever you move it, there is a risk that something will come out. In short, you will not do a good job. Something similar can also happen when a heart valve needs to be replaced in a child or young person. If the size of the pulmonary valve of those suffering from congenital malformations is greater than that of the “substitute”, surgery through minimally invasive techniques will be practically impossible.
The valve that adapts to the anatomy of children and young people
Now, to tackle the problem, in extremely selected cases, a self-expanding pulmonary valve bioprosthesis is aimed at adapting more effectively to the anatomy of children and young people with congenital heart disease. The device is inserted without the classic surgery, but only by going up the blood “ways” thanks to a special catheter, avoiding the avoidance of open heart surgery. The new prosthesis, which received EC authorization in May of this year, is already a reality in the Interventional Cardiology Unit of the Bambino Gesù Pediatric Hospital, directed by Gianfranco Buterawho used it successfully for two boys aged 15 and 19.
The valves of the heart are responsible for regulating the normal flow of blood in, out and within the organ. There are four of them and the pulmonary valve is one of them. It connects the right ventricle and the pulmonary artery, has the task of ensuring that the blood proceeds smoothly, without reflux, on its way to the lungs to recharge with oxygen. Unfortunately, it does not always work at its best, as happens for example in Fallot’s tetralogy, one of the most frequent severe congenital heart diseases that over time leads the right ventricle to sustain excessive work, arriving at decompensation. In these cases it may be necessary to replace the valve prosthesis that replaces the natural valve that does not function. Normally the procedure takes place in the hemodynamics room in a minimally invasive way, without the need for open heart surgery, by inserting a cannula into an artery, inside which a catheter (flexible tube) of dimensions minimum that is placed where there is the problem to be solved.
How important is size
Prostheses to be implanted without the classic operation have been used for several years. They are biological in nature with a synthetic metal ring and are based on “balloon expandable” technology. What does it mean? The valve is inserted with a balloon that is inflated and widens the stent placing the prosthesis in the desired position. But be careful: the balloon cannot dilate too much and when the space on which to operate is wider than about 16-29 millimeters, the system cannot be used. Unfortunately, the underlying disease can lead to ventricular decompensation, and consequent increase in size, the space of the valve, which can also be modified for operations already undergone or for specific patient situations. For this reason, only one in five patients who need to replace this valve can be treated in this way.
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The value of new technology
The new technology is based on the “self-expandable valve” system. It means that space is “gained” thanks to a self-expanding stent capable of reaching larger diameters – up to about 36 millimeters – greatly increasing the number of patients eligible for treatment. Every year, the Bambino Gesù is operated on about 30 children and young people: a number that can be more than doubled with the new technique, avoiding open heart surgery. The Infant Jesus is the first European hospital to use this technology after clinical approval. It has also been identified as a reference point for Italy and Europe and will have the task of promoting its use in the other centers, also taking care of the training of operators.
Treatment on selected cases
Obviously, this treatment is planned with great care. First the anatomy and functioning of the structures are studied with great attention with magnetic resonance and computed tomography, then the aim is to “manage” what is observed with 3D technology. The reconstruction of the three-dimensional image allows to highlight the points of the heart wall and pulmonary artery on which the valve will rest and allows an accurate evaluation of the patients who can receive the treatment. Furthermore, the computer simulation of the intervention, thanks to an algorithm that processes the data of the young patient, allows to anticipate any problems that may occur and to better plan the procedure. All this takes place thanks to the collaboration between the interventional cardiology unit and the advanced thoracic and cardiovascular radiology unit directed by Aurelio Secinaro.
What will change in the future
The two boys who were implanted with the pulmonary valve prosthesis were also able to avoid hospitalization in intensive care. Furthermore, while in the case of traditional surgery the average hospital stay is approximately two weeks, in these cases the patients were discharged only three days after the operation. These are the great advantages of this innovation, which appears destined to expand its uses. “It is possible to predict – explains Butera – that in Italy at least one hundred patients per year will benefit from this technology with a significant reduction in the impact also on the National Health Service but, above all, with a significant reduction in physical and psychological pain and risks for our children and great satisfaction for the families “.