New Surgical Technique Enlarges Aortic Root for Larger Valve Implantation

When replacing a diseased aortic valve, a small aortic root can prevent surgeons from implanting a prosthesis large enough for the patient’s body size. This can lead to patient-prosthesis mismatch, causing the heart to continue pumping against increased resistance and potentially worsening clinical outcomes while limiting future valve-in-valve options. To address this challenge, researchers have developed a surgical technique that enlarges the aortic root while preserving the established workflow of valve replacement.

The Alfred Kocher technique was developed at the Department of Cardiac and Thoracic Aortic Surgery at the Medical University of Vienna and University Hospital Vienna. The approach is designed for patients undergoing surgical aortic valve replacement when annular size limits prosthetic valve selection. It has been published with initial clinical findings in JTCVS Techniques.

The operation starts like a conventional aortic valve replacement. After measuring the aortic annulus, surgeons determine whether enlargement is needed. If required, the aortic root is expanded using a T-shaped incision and reconstructed with a specially shaped patch. The coronary arteries remain unaffected, and the natural geometry of the aortic root is largely preserved, allowing implantation of prosthetic valves at least two sizes larger.

The technique forms part of a broader effort to standardize surgical aortic valve replacement. The workflow includes measuring the native aortic annulus with a universally applicable measuring head, selecting the appropriate valve, and enlarging the aortic root when necessary. Several invention disclosures related to the approach have been submitted for patent in collaboration with the Department of Technology Transfer at the Medical University of Vienna.

“The key advantage of our technique is that we initially proceed as with conventional aortic valve replacement and only need to decide whether an enlargement is necessary after taking the measurements. With a comparatively simple additional surgical step, we can implant significantly larger prosthetic valves without affecting the coronary arteries. It is particularly important that the technique can be performed not only via conventional access but also using minimally invasive and even endoscopic methods,” said Alfred Kocher, head of the Heart Valve Team at the Department of Cardiac and Thoracic Aortic Surgery at the Medical University of Vienna and University Hospital Vienna.

“In aortic valve surgery, we must now take into account not only the immediate operation but also our patients' entire subsequent treatment pathway. A sufficiently large prosthetic valve is a key prerequisite for this. The new technique expands our ability to create optimal conditions for long-term care right from the first procedure,” said Daniel Zimpfer, head of the Department of Cardiac and Thoracic Aortic Surgery.

Related Links
Medical University of Vienna