Catheter intervention for aortic aneurysm – Handmade prosthesis for emergencies

Rupture of the abdominal aorta may be life-threatening. Men aged 65 to 75 are particularly at risk: of them,  two percent of this population has a dilated abdominal aorta which may later tear. An aneurysm is said to be present when the diameter of the abdominal aorta exceeds three centimeters at a given point.

The main causes of aortic dilatation besides increasing age include smoking and high blood pressure. Regular preventive examinations are recommended for patients at risk since the aneurysm itself causes no symptoms, “Critical dilatation of the vessel detected on ultrasound should be reviewed in consultation with specialists to decide whether preventive intervention is appropriate,” says Professor Alexander Zimmermann, head of the Department of Vascular Surgery at the University Hospital Zurich. Monitoring the situation for the time being may be appropriate in certain cases.

Computer guidance and a steady hand

Tears may now be repaired in emergency situations with a new, relatively gentle catheter-guided intervention. This is undertaken by means of a new procedure only offered at the University Hospital Zurich in Switzerland: the surgeon creates the prosthesis directly in the operating room, while anesthetists and nursing staff prepare for the intervention. The surgeon can modify the prosthesis with the help of the patient’s CT scan and computer simulation, such that it fits perfectly. “It requires a bit of tact,” says Zimmermann, one of the few who has mastered the procedure.

Although such catheter-guided interventions now form part of standard surgical protocols, they could not be deployed until recently in patients with aortic rupture involving vascular branches to various organs,  since several such vessels arise from this large artery. This vascular anatomy varies greatly from person to person and a standard prostheses therefore cannot be used. Alexander Zimmermann quickly builds a customized prosthesis himself as part of the new procedure. “Ordering them elsewhere would take four to six weeks. We only need one to one and a half hours if we do it ourselves,” he explains, being one of the few who have mastered this method.

The prosthesis is created directly in the operating room while the anesthetists and nursing staff prepare for the procedure. The surgeon can modify the prosthesis with the help of the patient’s CT scan and computer simulation, such that it fits perfectly. “One needs a bit of tact,” says Zimmermann.

The method is still relatively new, but the experience so far has been extremely rewarding, according to the expert. The procedure is only used in an emergency, in principle. Almost exclusively older patients, for whom open surgery would be too stressful, are furthermore managed with this technique. The procedure may not be  feasible in patients with atypical anatomy – namely when the position and shape of the vessels preclude a catheter-guided intervention.