Åke Senning

A milestone was the ingenious correction of a Budd-Chiari syndrome, crowned with success in 1981, in which he surgically removed the outflow stenosis of the hepatic veins through the right heart. This opened up a new path for liver surgery. This idea was in turn so groundbreaking that the banal liver puncture, a routine method, has nowadays been replaced by the transvenous, transatrial liver biopsy. This eliminated the risk of intra-abdominal haemorrhage.

Andreas Grüntzig, who first performed the now widely used coronary balloon dilatation in Zurich on 16 December 1977, needed Senning's assistance because the delicate coronary vessel could rupture during dilatation and the patient could die shortly afterwards. This first balloon dilatation in humans was performed in the animal laboratory of cardiac surgery, which not only had more modern equipment than cardiology, but also the neighbouring animal operating room could be converted at short notice for open-heart surgery in humans. Åke Senning and Marco Turina were standing by next to Grüntzig so that, in the event of a rupture of the coronary artery, they could intervene immediately with the surgical team standing by in the animal experimental laboratory. Andreas Grüntzig never forgot this and always mentioned the importance of Senning in the development of balloon dilatation. His direct superiors would never have allowed him to perform balloon dilatation on the coronary arteries.

On 14 April 1969, Senning performed the first heart transplantation in Switzerland, and shortly afterwards the second. He refrained from further heart transplants, stating that a heart transplant was not a surgical problem but a pharmaceutical one. Thus, regular heart transplants were not performed in Züriche until ten years later, when cyclosporine, which brought the clinical breakthrough of heart transplantation, was available. Nevertheless, Senning's already perfected surgical technique of heart transplantation is astonishing. Christiaan Barnard, the great South African heart surgeon, needed seven hours for the first heart transplant, whereas Senning needed three hours for the first and only two hours for the second, and this already in 1969! Senning's students thus opened the way for the introduction of heart transplantation in Switzerland.

Having barely arrived in Switzerland, Senning performed the first kidney transplantation in Switzerland on 17 December 1964 and shortly afterwards published the first major series of over 30 kidney transplants with cadaveric kidneys. Although the typing and organ reservation possibilities as well as the internal post-treatment therapy with immunosuppression were not yet sufficiently developed, his results of the first kidney transplants hardly differed from those of today. It is worth mentioning here that Senning's first kidney transplant series was the first to be published worldwide and that it was groundbreaking for the subsequent Largiadèr era.

In 1963 followed the first successful use of a left heart bypass, the first step for the LVAD (left ventricular assist device), the artificial left heart, so common today.

Together with Donald N. Ross in London, Senning also opened the way for anticoagulation-free follow-up of heart valve patients. Independently and without knowledge of D. Ross' autografting of the pulmonary valve, he developed the technique of aortic valve replacement by free autografts of the fascia lata two months after Ross in October 1962. Together with Martin Rothlin, he was then able to report, in 1971, 141 cases that he had corrected the aortic valve with this surgical method, as well as over 100 cases of mitral valve reconstruction. Again, this was one of his early Zurich achievements that was adopted throughout the world.

As Alfred Brunner's direct successor, he took up his post on 16 April 1961 as director of the Surgical University Clinic A in Zurich - with over 120 beds and 18 intensive care beds - where he worked with great dedication and energy until his retirement a quarter of a century later on 15 April 1985. In the first nine months of his tenure, 108 heart operations were performed, two years later 264 and in his last year in office 937. In 1969, he performed the first two heart transplantss in Switzerland. At the beginning of his Zurich days, the lethality rate of patients operated on by heart-lung machine was over 50 per cent and the age limit for such an operation was 35! Ten years later (1979), the lethality rate was less than one per cent, and the age limit was no longer the calendar age, but the biological age of the patients!

Few people know that the first intensive care unit in Central Europe was installed on 17 April 1961 in three offices of the Surgical Clinic A and that the world's first cardiac surgery intensive care unit, then called the Cardiac Awake Room, was set up in an aft room of the same clinic. Already in the first nine months of his tenure (1961), 108 heart operations were performed and treated post-operatively in this intensive care unit. Two years later there were already 264 and in his last full year in office in 1984 there were 937. With this, too, Senning wrote medical history.

Together with the electrical engineer Rune Elmqvist, Åke Senning developed the first implantable pacemaker in 1958, consisting of two externally rechargeable NiCd cells and a blocking oscillator (pulse amplitude 2.5 V, duration 2 ms, frequency 70 Hz) with two germanium transistors. The components of the first device were placed in a shoe polish box and this was filled with epoxy resin.

When Senning implanted this first implantable pacemaker in the 43-year-old patient Arne Larsson on 8 October 1958 and subsequently developed this invention further, he was asked on several occasions to patent his research results. However, Senning was opposed to any medical patent on the grounds that valuable time would be lost and that the suffering people would only benefit from his idea much later. He repeatedly said: "Medical discoveries belong to the patients and not to the inventor. If we hadn't invented it, someone else would have done it tomorrow". If he had earned even a few francs from each pacemaker, he would have been spared the eternal search for research funds. This innate spontaneous wisdom testifies to Senning's unusual reverence for the sick person. For him, freedom of research and ethics of the researcher were indispensable requirements for medical research.

Two years later (1956) he performed the first total correction of a congenital malposition of the junction of the pulmonary veins with the left atrium, and in 1958 the first total correction of a complete transposition of the great vessels mentioned above.

Since 1955, long before the first bypass operation by René Favaloro in Cleveland in 1968, Senning had been experimentally and later clinically involved in coronary surgery. In 1958, he successfully performed the first coronary operation worldwide using the strip-graft technique, i.e. the first endarterectomy of the coronary arteries, which was completed with a vena saphena graft. In the same year, he inserted an implantable pacemaker for the first time, a step that would later save the lives of millions.

Together with Clarence Crafoord, he performed the first successful open-heart surgery on humans in Europe using the heart-lung machine in 1953.

As early as 1951, he completed the extracorporeal circuit technique, using electrically induced ventricular fibrillation during cardiac arrest to prevent air embolism and hypothermia to reduce oxygen consumption. Decades later, when asked what was the most important of his inventions, he replied: Electrically induced ventricular fibrillation to prevent air embolism; that saved the most lives! Later it was replaced by drug-induced cardioplegia.

Furthermore, the Björck's thoracoplasty, which was first performed by Senning while still in Stockholm, and the funnel chest correction according to Senning-Johansson, which was first performed in 1951.

Senning's personal contributions to the development of cardiac, vascular and thoracic surgery begin as early as 1949 with the development of a Roller Oxygenator, which was successful in animal experiments in 1951 and successfully used in the world's second operation on humans and the first in Europe in 1953.

Åke Senning was born to the Swedish veterinarian David Senning and the nurse Elly Senning, née Säfström. He finished his schooling in Uppsala with the baccalaureate. He actually wanted to become an engineer. However, as a nurse in World War 1, his mother persuaded him to study medicine. He subsequently completed the pre-clinical part of his studies in Uppsala, the clinical part and his state examination in Stockholm in 1948. His subsequent further training in Stockholm included general surgery, orthopaedics and thoracic and neurosurgery.

Clarence Crafoord introduced him to the field of cardiac surgery in 1948. The influence of this eminent surgeon, who had a major impact on thoracic and cardiac surgery, sparked Senning's love of cardiac surgery and thus helped determine the direction of his work throughout his life. Åke Senning has always thanked his academic teacher for this and held him in high esteem. With his work on electrically induced ventricular fibrillation to prevent air embolisms in cardiac surgery, he significantly reduced the risk of complications in cardiac surgery. With this, Senning became a private lecturer in Experimental Thoracic and Cardiac Surgery in Stockholm in 1952 and was appointed Extraordinary Professor of Surgery in 1956. In 1957 he was elected senior physician in the Department of Thoracic Surgery at the Karolinska University Hospital (Karolinska Sjukhuset). In 1961, he followed the call to the chair of surgery at the University of Zurich and thus succeeded Theodor Billroth, Rudolf U. Krönlein, Ferdinand Sauerbruch, and Alfred Brunner.

Åke Senning (* 14 December 1915 in Rättvik, Sweden; † 21 July 2000 in Zurich, Switzerland) was a Swedish cardiac surgeon who worked at Zurich University Hospital from 1961 until his retirement in 1985.