Inventor of the Valsalva aortic graft Ruggero De Paulis (European Hospital Unicamillus University, Rome, Italy) tells Cardiovascular News about his unique inspiration for the device. A past president of the European Association of Cardio-Thoracic Surgery (EACTS), he turns back the clock on his career in cardiac surgery.
Why did you choose to become a doctor and cardiac surgeon?
I began medical school in my hometown, L’ Aquila, at the age of 17. At the time, I was not really thinking of my future or professional life. My father was a doctor, and I think part of my choice was the desire to follow in his steps—although he did not try to influence my decision, but I always thought that healing and helping people is one of the most rewarding activities for a human being.
Once you start studying medicine, it is common to fall in love with every organ or disease you get to know better. Towards the end of my studies, I realised that I wanted to do something with my hands, and surgery, more than clinical medicine, was the first choice. I also had a passion for the cardiovascular system. Putting this together pointed to cardiac surgery. I applied for residency at the University of Torino where I moved, driving all the way in my old Citroen 2CV. After the first month in the operating room, I knew this was the place I wanted to be.
Who were the biggest influences on your earlier career?
Mario Morea, the director of the cardiac surgery department at the University of Torino, could be considered an early pioneer, especially in the field of valve surgery at the time when bioprostheses first appeared. Besides his huge experience in all aspects of cardiac surgery, he had a genuine interest for all innovations and an innate sense of curiosity. Since our first encounter, he pushed me to concentrate on education and research more than pure manual surgical activity. He used to say: “With six intensive months you can learn how to move your hands—it takes much longer to understand what the right thing to do is”. In a more practical way, one of the staff surgeons, Gianmaria Ottino, helped me to enter the field of scientific reading and publication as well as managing databases and statistical calculation. For both I feel a profound sense of affection and gratitude.
What is the story of how and why the Valsalva graft came in to being?
At the end of 1980s when stentless valves were developed I was prompted by the chief of my residency programme to study the physiology of the aortic root to better understand the potential for this approach. I embarked on reviewing a series of old in vitro and in vivo studies, and learned that the aortic root, differently from the rest of the ascending aorta, expands almost exclusively on the horizontal plane while its longitudinal compliance is almost zero.
Two types of valve-sparing operations were introduced by Magdi Yacoub and Tirone David at the beginning of 1990, but they were rarely performed by other surgeons. At major cardiac surgical meetings, I witnessed the two surgeons confronting the peculiarity of their techniques many times. The critical points were always the same: Yacoub claimed his technique was more physiological because it re-established the sinuses of Valsalva while David claimed his technique was more durable because it addressed the annular dilatation. The most important aspect remained a matter of debate.
I was intrigued and obsessed with finding a solution that could somehow combine the two options. One day, when assisting on a Bentall operation, I started thinking of a material that would stretch horizontally to fill the space previously occupied by the root aneurysm. Such material still does not exist, but on the way home I kept thinking that a cylindrical conduit was certainly not the best solution for substituting a pear-shaped piece of anatomy. Once I entered my house, the solution was simply hanging in front of me! My wife, a fashion designer, had been working on a peculiar dress completely made by pleated tissue material. The upper part had horizontal pleats while the lower part, corresponding to the skirt, had vertical pleats that would naturally open and close. I remained speechless for a long period while suddenly visualising the perfect shape for a Bentall procedure and the potential for providing sinuses to a David procedure. I immediately went back to collect some spare aortic grafts and, on the kitchen table with the help of my wife, cut open a corrugated Dacron graft, rotated it by 90 degrees and sewed it back on. The Valsalva graft was born.
In the following days I worked on lengths and diameters to find the optimal solution that would respect anatomical and physiological parameters—dimensions and proportions that have not been changed ever since.
What lessons can you impart on budding surgeon innovators?
The first challenge was finding a company that might be interested in producing a commercial version of my prototype. After six months of discussion with a major manufacturer of Dacron grafts, I was turned down because they had other priorities. A little depressed after this experience, with the help of a friend I was put into contact with a second company, where I met Roshan Maini, who had the patience to listen to all my explanations about anatomy and physiology, and the wisdom to see a future where aortic surgery and valve sparing operations would flourish. After the first prototypes were implanted and imaging showed excellent root reconstruction in all different techniques, the Valsalva graft was introduced into clinical practice.
At this point the challenge was to convince the surgical community of the potential benefits of a graft designed for the aortic root. Bench experiments, postoperative imaging and clinical follow-up had been used to show the benefit of an easier procedure, coupled with an optimal anatomical root reconstruction yielding good, long-lasting results. The lesson is that a good idea is not always enough—a lot of work needs to be done afterwards. In simple terms, the formula is 10% genius and 90% perspiration.
How has the Valsalva graft changed the face of aortic root replacement?
My initial hope was to change the standard of care for patients where a root replacement was needed, no matter whether it was associated with aortic valve replacement or a valve sparing operation. After 20 years I feel that this has been fulfilled and, in the near future, I envisage that the great majority of root surgeries will be performed using a Valsalva graft. By providing neo-sinuses in a simple and standardised fashion, the Valsalva has two main benefits. From one side it facilitates surgery, making coronary button reimplantation easier in all the various anatomical presentations. From another side it provides vortex inside the neo-sinuses, guaranteeing a physiological cusp motion with larger orifice area in systole and smooth leaflet closure during diastole. Altogether it should improve durability and longevity both for bioprostheses and natural valves.
From a research point of view the Valsalva graft has been demonstrated to be a formidable tool to study the anatomy and physiology of the root, the effect of suboptimal root reconstruction on the aortic cusp movement, as well as the effect of the sinuses on coronary flow, among many other experimental studies on flow turbulence or wall stress, for example.
You also played a part in the development of the Physioflex ring for mitral repair. What has this innovation added to the field?
Alongside the design of the Valsalva graft, this device shares the desire to always mimic normal human anatomy and physiology. Mitral rings have been in use for many years, both in the form of complete rings or open bands, and changes and improvements have happened in small steps.
The design of the Physioflex ring starts from the belief that the anterior portion of the mitral curtain does not need to be immobilised by a ring but left free to move during the cardiac cycle. During systole the root needs to expand and wedge into this region. Leaving this anatomical region free from prosthetic material offers the opportunity for a larger effective orifice area in the left ventricular outflow tract (LVOT) during systole and a larger effective orifice in the mitral during diastole. On top of this, the Physioflex has a complete saddle shape to offer the advantages of a good annuloplasty while maintaining a proper ring shape necessary to guarantee optimal leaflet apposition and coaptation, with reduced stress for the various elements of the mitral valve complex.
What are your current research interests?
At present we are working on a better understanding of the pathology of the bicuspid valve and the potential for standardisation of aortic valve repair in different anatomical presentation. Overall, the ability to repair the majority of purely regurgitant aortic valves is certainly appealing and it is important to popularise and diffuse these techniques.
On a different level we are interested in better understanding intraventricular flow and how flow is modified depending on specific pathologies, the type of surgery or the type of devices utilised.
How important has your involvement in EACTS been for your career and research?
My time at the EACTS, first as a chair of the vascular domain, and then as president, has contributed to a personal boost of visibility and increased my professional connections across the world. The time spent in shaping many annual meeting programmes, coupled with contribution in the general governance of the Association, has been an extremely rewarding experience that continues today. In fact, I now have the honour of chairing the Francis Fontan Fund (FFF) that provides scholarships to young colleagues with specific interests in various aspects of our profession. Education is certainly the main focus of an association like EACTS and the FFF represents one of its best expressions.
Outside of medicine, what are your hobbies and interest?
During my studies, I used to play rugby and basketball for my hometown teams. After entering the cardiac surgery residency, I had less time for team sports. Nowadays, I like outdoor activity like running, swimming, or cycling to keep in a good shape. However, my great passion has always been alpine skiing. I think I will try to maintain this activity as long as possible. I spend my free time in Puglia with my wife, even during the winter, in close contact with the sea and nature.