New form of therapy reduces mortality rate
(Vienna, 10 May 2010) With a new method which is applied in only a few cases worldwide the Vienna Aneurysm Team of MedUni Vienna has now been able to conduct the first operations successfully. This minimally invasive type of endovascular surgery, which requires only minor incisions rather than opening the abdominal wall or thorax, drastically reduces the mortality rate, particularly in older patients.
Aneurysms in the aorta (the main artery) are balloon-like bulges of blood vessels, which most commonly occur from the age of 65 onwards. From a size of 5-6cm there is an increased risk of rupture. This can result in life-threatening inner haemorrhage. "Classic" aneurysms of the abdominal aorta can either be treated with open surgery or by using a minimally invasive procedure, placement of a so-called stent graft. The Vienna General Hospital AKH was one of the first centres in the world to provide this "endovascular" form of therapy, and it has been conducted on a large scale since 1995.
"Complicated" aneurysms, on the other hand, are a particular problem because in this case the aneurysm also affects the terminal branches of the hepatic, abdominal and the two renal arteries ("thoracoabdominal aneurysm"). Previously in Austria it had not been possible at all – and internationally only in individual cases – to use stent grafts in endovascular surgery to treat such aneurysms. This procedure is now also being applied successfully at the Clinical Centre of MedUni Vienna by the interdisciplinary Vienna Aneurysm Team, which comprises radiologists, cardiac and vascular surgeons.
The new form of treatment
For the "endovascular" therapy it is necessary to insert a prosthesis (a so-called stent graft) through the femoral artery and arm artery under x-ray monitoring first into the main artery (aorta), then a connection is made to the major organ arteries (liver, spleen, intestine, kidneys). This is done by using smaller plastic prostheses that are connected with the openings in the main prosthesis. This intervention – though conducted under anaesthesia – does not involve the opening of the chest or abdominal cavity. All manipulations are conducted solely in the form of minor superficial incisions in the groin and near the left and right axilla under x-ray monitoring. Patients are therefore subjected to very little stress. They often do not need to be admitted at the intensive care unit and are allowed to go home after only around four days if progress is positive. As each stent graft needs to be tailored to the individual patient, however, the planning stage takes some weeks, during which time their blood pressure needs to be strictly checked and they need to avoid stress to minimise the risk of rupture of the aneurysm during this planning stage.
15 years of the Vienna Aneurysm Team
Following the first successful interventions, this surgery was conducted on as many as 29 patients in 1995. Over the past 15 years, the team of the Division of Cardiovascular and Interventional Radiology has treated over 800 patients at the University Clinical Centre AKH Vienna, the majority of these patients suffered from an abdominal aortic aneurysm and were treated in cooperation with the Division of Vascular Surgery by applying EVAR ("endovascular aneurysm repair"). Nowadays surgery is conducted in a specially created operating room (the so-called "Endovascular Suite"), which is equipped with a state-of-the-art x-ray system and anaesthesia facilities; following the intervention, patients can immediately be transferred to the normal ward. Mortality in a planned aneurysm intervention using the conventional open repair was between 4.6% and 5.3%, but could also be as high as 19.2% in patients with a higher risk profile (ASA IV). Mortality in an EVAR procedure, however, is between 1.2% and 2.1% and does not exceed the 5% mark even in high-risk patients. In two major randomised trials (EVAR I, DREAM) it was also possible to prove that EVAR has a significantly lower surgery risk than the open method.
In a further development of this method, the Thoracic Aneurysm Team around Lammer, Grimm, Funovics and Czerny was the first worldwide to implant an aortic prosthesis percutaneously under x-ray monitoring in a "Type A dissection", which affects the artery near the heart. The dissection of the aorta near the heart is a particularly life-threatening disease with high mortality, which led to the death of the former Austrian federal minister and Olympic silver medallist Lise Prokop, for example.
The Interdisciplinary Team of the Medical University of Vienna has also boasted international scientific successes thanks to these pioneering achievements. It has published 75 publications in international journals. The therapy was also presented for the first time in the most renowned clinical journal, the "New England Journal of Medicine", with additional publications following in top-notch journals such as "Circulation", "Journal of Vascular Surgery" and "Radiology". In addition, the Team’s major experience has brought many prominent and also foreign patients to Vienna. Furthermore, an international congress on this theme involving experts from across the globe has been held in Vienna for more than 10 years (Vienna International Symposium on Aortic Repair – VISAR).
This successful Vienna Aneurysm Team comprises interventional radiologists (Univ. Prof. Dr. Maria Schoder, Univ. Doz. Dr. Martin Funovics, Univ. Prof. Dr. Johannes Lammer) together with heart surgeons (Univ. Prof. Dr. Marek Ehrlich, Univ. Prof. Dr. Michael Grimm, Univ. Prof. Dr. Günther Laufer) and vascular surgeons (Univ. Prof. Dr. Igor Huk, O.Univ. Prof. Dr. Peter Polterauer).