Seoul St. Mary's Hospital performs South Korea's first LLAMACORN valve procedure

Seoul St. Mary's Hospital of the Catholic University of Korea announced Wednesday that a team led by Professor Jang Gi-yuk of the cardiovascular and cerebrovascular center's cardiology department completed South Korea's first LLAMACORN procedure on July 22.

The procedure is a new, high-complexity approach to transcatheter aortic valve implantation (TAVI) and was performed on an 89-year-old female patient. TAVI treats aortic stenosis — a condition in which a hardened aortic valve obstructs blood flow, causing shortness of breath, chest pain and fainting — using a catheter, without open-heart surgery.

However, an artificial valve inserted this way can deteriorate or become damaged over time. When that happens, a new valve is placed inside the existing one in a procedure known as valve-in-valve (ViV) TAVI.

The challenge with ViV procedures is that as the new valve is nested inside the old one, the leaflets of the existing valve can be pushed upward and block the coronary artery openings, potentially triggering a heart attack. Because of this risk, leaflet management techniques are considered essential before any ViV procedure.

The first such technique developed was BASILICA, which uses a wire to fully lacerate the at-risk leaflet and split it open into two flaps. The UNICORN technique followed in 2022. LLAMACORN is the next advance in that line of development.

LLAMACORN is a high-difficulty re-intervention technique for patients at high risk of coronary obstruction from existing prosthetic valve leaflets. It reduces the constraints imposed by the type of existing valve, broadens the choice of replacement valve and ensures adequate blood flow to the coronary arteries — making it a new alternative in valve re-intervention.

A research team at Princess Alexandra Hospital in Australia first reported the technique in an international academic journal in 2024. Unlike UNICORN, which had limited valve compatibility despite its complexity, LLAMACORN can be applied with a wider range of valves — though it is technically more demanding — allowing clinicians to select the valve best suited to each patient.

Rather than simply puncturing the existing leaflets, LLAMACORN removes them entirely, fundamentally preventing coronary obstruction while securing a wider blood flow channel and minimizing stenosis.

The successive successes of South Korea's first BASILICA and LLAMACORN procedures at the cardiovascular and cerebrovascular center are seen as a clear demonstration of the hospital's capabilities. The availability of multiple approaches and techniques for patients requiring complex re-interventions is considered a factor that contributes to more stable outcomes.

The patient in this case had previously received a small balloon-expandable valve, which led to relatively early valve degeneration. A self-expanding valve was considered for its superior hemodynamic performance. However, the patient's anatomy — specifically a relatively low left coronary artery height — meant that inserting a new valve carried a very high risk of the existing valve leaflet folding sideways and completely blocking the left coronary artery opening.

Professor Jang's team therefore determined that LLAMACORN, using a self-expanding valve to fully lacerate the leaflets, was the best option over the UNICORN approach.

"A significant number of patients who need a repeat valve procedure after their TAVI valve deteriorates face the life-threatening risk of coronary artery occlusion, which has long limited the interventional treatment options available to them," said Jang, who led the procedure. "LLAMACORN can fundamentally reduce that risk, and I am pleased that we can now offer these patients a new alternative."