Research into the changes of stentgrafts to treat a dilated aorta and how they behave after surgery leads to new advice to vascular surgeons. The new advice ensures improved placement of these stentgraft prostheses and improved monitoring of patients after surgery. In addition, the results of these studies help manufacturers to further improve stentgraft prostheses as manufacturers now better understand the movement and changes of stentgrafts. Jaimy Simmering, scientific researcher in the Department of Surgery at MST and at the University of Twente (TechMed Centre), obtained her PhD on this study.
A dilation of the aorta - also called an aortic aneurysm - is a form of cardiovascular disease caused by weakening of the vessel wall. If left untreated, an aortic aneurysm can rupture. What follows is life-threatening internal bleeding. This is why most aneurysms are treated starting from a certain size. This is often done through a puncture in the inguinal artery. Through these arteries, a surgeon places a stentgraft prosthesis in the aorta, at the site of the aneurysm. Jaimy Simmering: "You can imagine this as placing a new inner tube: the blood now goes through this stentgraft. This takes the pressure off the weakened vessel wall and minimises the risk of rupture."
Although the results of these 'inner tube surgeries' are successful in the first few years, in some cases another surgery is still needed. The heart beats about 30 million times a year and each heartbeat puts the stentgraft to the test. If the artery expands, for example, the stentgraft may leak at the connections. Also, changes in blood flow can cause part of the stentgraft to close. Jaimy Simmering: "We don't always know why this happens. To gain more insight into this, the studies in this thesis looked at any changes to the shape of stentgraft prostheses in the months and years after surgery. This was done with CT scans linked to heart rate, so we could also measure the changes in movement of stentgraft prostheses during heart rate at different times after surgery."
On Friday 14 April, Dr Jaimy Simmering successfully defended her thesis: "her research technique should become the standard before we apply new stentgraft prostheses in humans". She was a PhD candidate in the Multi-Modality Medical Imaging research group (M3I; Faculty of S&T / TechMed Centre). (Co)promoters are Prof R.H. Geelkerken and Dr E. Groot Jebbink from the faculty of S&T and Prof C.H. Slump from the Faculty of EEMCS.