So-called stent grafts - vascular supports made of very fine wire mesh with a plastic coating - reliably stabilize life-threatening dilatations of the aorta. For the uppermost section of the human aorta, the aortic arch, there has been no satisfactory solution in the near future due to the arteries branching off to the brain and arms. On January 30, 2024, the team at the Clinic of Vascular Surgery at Heidelberg University Hospital (UKHD) implanted a new type of stent graft specially designed for this section of the aorta via catheter intervention for the first time in Europe: An opening is cut out in the wire mesh of the prosthesis for the branch of the left brachial artery or carotid artery. Another smaller stent graft is inserted there to ensure that this important vessel is adequately supplied with blood.

Professor Dr. Dittmar Böckler, Medical Director of the Clinic for Vascular Surgery and Endovascular Surgery at the UKHD, was involved in the development of the innovative vascular prosthesis. It was approved in the USA in 2022 and is now available outside the USA for the first time. He says: "The new stent offers a minimally invasive alternative for the first time, especially for patients who can only undergo open surgery at high risk. I am convinced that this procedure will very quickly become established in the major vascular centers." The first two patients in Heidelberg tolerated the procedure very well and are already back on the normal ward.

In Germany, the so-called TBE stent grafts (Thoracic Branch Endoprothesis) are used at six large German vascular and aortic centers with a high level of expertise and the corresponding technical equipment. The accompanying registry study is coordinated and managed by Heidelberg University Hospital.

Aneurysms of the posterior aortic arch usually require two operations

A so-called aortic aneurysm, a dilation of the aorta, should be bridged and stabilized as soon as it reaches a certain size. Otherwise there is a risk that the vessel wall will rupture at this point and the patient will bleed to death within minutes. While aneurysms in the abdominal cavity have been treated primarily endovascularly, i.e. by means of catheter intervention, for 20 years, this has not yet been possible in standard care for the aortic arch: until now, only individually manufactured endoprostheses with a manufacturing and therefore waiting time of two to three months have been available.

Until now, open surgery had to be performed in acute emergencies: "First, the brachial artery is connected to the left carotid artery by means of a bypass in a first operation, then the aneurysm is stabilized with an endoprosthesis via an access in the groin in a second operation a few days later," explains Professor Böckler. "For patients, this means two operations, anesthesia and hospitalization, including intensive care. The new stent can significantly reduce these burdens." This is because a catheter procedure is all that is needed to insert the TBE stent, no artery has to be moved and the only "wound" is the ultrasound-guided puncture of the vessel in the groin, as in a cardiac catheter examination. "Patients only stay with us for a few days for follow-up observation and can be discharged fit to go home," says the vascular surgeon.

Technical equipment in the hybrid operating room allows the stent to be placed with millimeter precision

The UKHD Surgical Clinic has two hybrid operating theaters with high-precision intraoperative imaging specifically for complex procedures such as this. The X-ray detector on a robotic arm can take images from any direction and generate three-dimensional, directly available images. In addition, previously acquired computer tomography images can be inserted into the intraoperative X-ray image during the operation (fusion imaging). "Three-dimensional navigation with millimeter accuracy and precise placement of the stent is essential. In an emergency, we can also switch to open surgery or call in colleagues from cardiac surgery if necessary - without having to transfer the patient to another operating theater. This ensures additional safety during these difficult, often life-saving procedures," says Prof. Böckler. Every year, his team operates on around 100 patients with aneurysms and dissections of the posterior aortic arch in cooperation with the Department of Cardiac Surgery. Between 15 and 20 high-risk patients will benefit from the new procedure in 2024. "In the coming years, the proportion will increase thanks to this new technology and treatment strategy," says Prof. Böckler.