The Mainz University Medical Center is blazing a trail by appointing the very first professor of interventional heart valve repair in Germany. It plans to enlarge its Department of Internal Medicine and its and its Department of Cardiothoracic Surgery in order to further promote its existing status as one of the leading treatment centers in this recent field of medicine. Ulrich Hink, the first holder of this professorship, explains what exactly is involved and describes the rapid developments in his discipline.
The enthusiasm is apparent from the way that Professor Ulrich Hink talks about his work – and he frequently uses expressions that one might not necessarily expect from a physician. "We can do extraordinary things here," he begins, "it's just awesome!"
Hink holds a container in his right hand. There is something shiny inside that looks like a small crown made of a silver-colored metal. Carefully mounted inside it is a pale yellow membrane. The entire thing is about the size of a jewelry ring. "This is a biological aortic valve," says the 45-year-old specialist.
New heart valve without surgery
The best part is that the cardiologist does not need to perform surgery to implant this device in a heart but instead guides it to its destination via the femoral artery with the aid of a catheter. "The procedure is quite new. It was first approved in Germany in 2007. We have been using it since July 2008."
The procedure is called transcatheter aortic valve implantation or TAVI for short. It is just one form of a non-surgical heart valve replacement technique, a concept that is still in its infancy but for which Hink predicts a great future. "Many incredible new things have been developed," he says. "And they are relevant to very many patients."
The importance of the new field is correspondingly high. In recent years, the Department of Internal Medicine, of which Hink is the Deputy Director, and the Department of Cardiothoracic and Vascular Surgery at the Mainz University Medical Center have joined forces to become one of the leading centers offering treatments of this kind. The plan is to now further extend their expertise and dominance in the field. Thus, the Mainz University Medical Center has created Germany's first Professorship of Interventional Heart Valve Repair and appointed Hink.
The original idea for this professorship came from Professor Thomas Münzel, Director of the Department of Internal Medicine. Professor Christian Friedrich Vahl, Director of the Department of Cardiothoracic and Vascular Surgery, gave his support to the concept.
"The heart valves regulate the flow of blood in the heart," explains Hink. "They change in the course of life. The aortic valve, for example, can become calcified and, as a result, the opening of the valve may be narrowed. The heart must then expend more and more effort to pump the blood through." This condition is called aortic valve stenosis. Patients may remain without symptoms for a long time but by the time they do come to realize something is wrong, their situation is already critical. "Of these cases, 50 percent die within a year."
Help for many patients
The disease mainly occurs in the elderly. Most patients are over 70 years old. Some are unable to withstand the stress of conventional heart surgery procedures. Up to now, there has been no effective treatment for these patients. But that has now changed. "All of a sudden we can help a whole group of people."
Hink picks up a catheter. The tube has a diameter of 5 millimeters. "Six months ago, we were still using a catheter with a diameter of 7 millimeters. We are also making rapid progress here." A balloon made of plastic is mounted near to the soft tip of the catheter. It is still limp and empty. The artificial heart valve is then placed over this balloon. The supporting structure in the form of the tiny coronet can be folded together like an accordion.
The catheter is introduced into the femoral artery and guided along a previously inserted wire to the calcified cardiac valve. Once it is in position, the surgeon inflates the tiny balloon which causes the artificial biovalve to unfold and attach itself to the inside of the diseased heart valve. "The plaque deposits actually help us. They provide a good foundation to which we can anchor the new valve," says Hink.
Mainz as an exchange platform
"There are hospitals in which such procedures are performed under local anesthesia only. However, we prefer general anesthesia because it is simply less stress for the patient." Once the procedure has been completed, the patient remains under observation for 24 hours in our intensive care unit. Only in some cases are rehabilitation measures or similar necessary. "Thanks to this technique, we are now able to cause as little impact as possible on the quality of life of our elderly patients. Not only that, but following successful treatment of this often fatal disease, many older people enjoy a completely new lease on life.
"This procedure is not intended to be a replacement for conventional heart surgery," emphasizes Hink. "We do not see ourselves as competitors." It is still unclear whether the new valves are as resilient as the tried-and-tested versions that are implanted by means of surgery. "At first, the natural and artificial heart valve were sometimes not completely bonded together so that there were leaks." But there is continuous improvement in this aspect. In case it happens anyway, Hink knows what to do: using a catheter, he can insert a kind of plug to stop any leak.
The University Medical Center of Johannes Gutenberg University Mainz (JGU) is hoping that the new professorship will have a signal effect. "We are progressing by leaps and bounds in the field of interventional heart valve repair. The industry, materials research, cardiac surgeons, cardiologists, and many others are involved in the developments. We in Mainz hope to act as a kind of hub or a platform through which everyone can exchange ideas and insights." Industry needs to consult with physicians and make use of their know-how and experience in the development of new products – and the better the materials, the better new artificial cardiac valves will be.
Ever new methods and materials
"But we can already do such a lot," says Hink. "This artificial aortic valve is just an example. Would you like to see more?"
The cardiologist takes out another aortic valve made from a metal alloy that contracts in the cold but which the natural warmth of the heart causes to adapt to the shape of the calcified aortic valve. Hink takes a so-called MitraClip between his thumb and index finger; this is a metal clip that can be used to repair diseased sections of the mitral valve. He then hints at a mechanism that can be placed around an enlarged mitral valve to help reduce it to its original size. "We will soon even be able to attach tendons to the surface of valves," he states. And he flips open a brochure: "These are filters that prevent detached particles of plaque from a heart valve reaching the brain."
The brave new world of interventional heart valve repair is already rich in devices and it is continuously getting richer. Hink knows this himself and his enthusiasm shows. "It is really amazing," he repeats. "It’s incredible what we can make nowadays."