Catheter intervention for aortic aneurysm – Handmade prosthesis for emergencies
The aorta is the main artery in the human body. The largest and most important artery transports blood from the heart to the various vessels. If it ruptures, this can be life-threatening.
Unique procedure at the USZ
In the event of an emergency, the University Hospital Zurich offers a procedure that is unique in Switzerland. A surgeon creates a customized prosthesis directly in the operating theatre.
A rupture of the abdominal aorta can be life-threatening. Men between the ages of 65 and 75 are particularly at risk: around two percent of them have an expansion of the aorta in the abdominal area, which can lead to a rupture. Such an aneurysm occurs when the abdominal aorta reaches a diameter of more than three centimeters at one point.
In addition to age, smoking and high blood pressure are the main causes of the expansion. Because the aneurysm itself does not cause any symptoms, regular check-ups are recommended for patients at risk. “If the doctor detects a critical expansion on ultrasound, it should be checked in consultation with specialists whether preventive surgery is appropriate,” says Professor Alexander Zimmermann, Head of the Department of Vascular Surgery at the University Hospital Zurich. In certain cases, it is also appropriate to simply monitor the situation for the time being.
With computer assistance and a steady hand
If an emergency does occur, the rupture can now be repaired using a new, relatively gentle catheter procedure. This is made possible by a new procedure that is only offered at the USZ throughout Switzerland: the surgeon creates the prosthesis directly in the operating room while anesthetists and nursing staff prepare the operation. With the help of a CT scan of the patient and a computer simulation, the surgeon knows how to modify the prosthesis so that it fits perfectly. “It takes a bit of flair,” says Zimmermann, who is one of the few people to have mastered the method.
Such catheter interventions are standard in surgery today. However, until recently they were not possible in the case of a rupture of the aorta in the area of the organ vessels. This is because numerous vessels branch off from the artery in the abdominal area. This anatomy is very individual, which is why no standard prostheses can be used. In the new process, Alexander Zimmermann builds a customized prosthesis himself without further ado. “Ordering them externally would take four to six weeks. If we make them ourselves, we only need one to one and a half hours,” he explains, who is one of the few people to have mastered the method.
The prosthesis is created directly in the operating room while anesthetists and nursing staff prepare the procedure. With the help of a computer tomography (CT) scan of the patient and a computer simulation, the surgeons know how to modify the prosthesis so that it fits perfectly. “This requires a sure instinct,” says Zimmermann.
The method is still in its infancy, but experience to date has been extremely positive, according to the expert. In principle, the procedure is only used in an emergency. In addition, almost exclusively older patients, for whom open surgery would be too stressful, are treated in this way. It is also possible that the patient’s anatomy precludes the procedure – namely if the position and shape of the vessels do not permit catheter intervention.
