“Cusp-Overlap” Technique Simplifies Implantation of Chinese Domestic Transcatheter Valves for TAVI

0
0
0

“Cusp-Overlap” Technique Simplifies Implantation of Chinese Domestic Transcatheter Valves for TAVI

Transcatheter aortic valve implantation (TAVI) has transformed care for people with severe aortic stenosis who are too sick for open-heart surgery. In China, TAVI has grown rapidly since 2010, with domestic devices like the Venus A-Valve (Venus MedTech, Hangzhou) leading the way—used in over 4,000 procedures to date. But getting these valves positioned exactly right during surgery remains a challenge. That’s where a simple yet powerful imaging technique called “cusp-overlap” is changing the game for doctors using China’s self-expanding Venus A-Valve.

The Problem with Standard TAVI Imaging

To implant a TAVI valve correctly, doctors rely on fluoroscopy (real-time X-ray) to view the aortic root—the area where the valve sits. The standard approach in China uses a “3-cusp view” that aligns the right coronary cusp (RCC) between the left (LCC) and non-coronary (NCC) cusps. But for self-expanding valves like the Venus A-Valve, this view can lead to parallax (visual distortion) or delayed feedback from the delivery system, increasing the risk of the valve “diving” into the left ventricular outflow tract (LVOT) or causing complications like pacemaker need or paravalvular leakage (PVL, when blood leaks around the valve).

Enter the Cusp-Overlap Technique

First described by cardiologist Gilbert Tang, the cusp-overlap view uses a fluoroscopy angle that overlaps the RCC and LCC, isolating the NCC in a clear “en-face” view. For the Venus A-Valve—designed with radiopaque markers 0.5 cells above its inflow end to guide placement—this isolation is key: it gives doctors a sharper anatomical reference for how deep to implant the valve, reducing visual distortion and making deployment more predictable.

Why It Works for Venus A-Valve

The Venus A-Valve has two unique traits that make cusp-overlap especially helpful:

  1. Quicker frame “flowering”: The valve’s frame expands faster than devices like the Evolut Pro (Medtronic), so precise timing is critical.
  2. Delayed delivery system feedback: The knob doctors turn to deploy the valve doesn’t move in perfect sync with the capsule holding the valve.

The cusp-overlap view solves both issues. By centering the delivery catheter and shortening the “flowering” distance from the NCC to LCC, it reduces the risk of the valve shifting too far into the LVOT. And because the NCC is isolated, doctors can use the valve’s radiopaque markers to hit the optimal “landing zone” every time.

Real Benefits for Patients

Early use of the cusp-overlap technique with the Venus A-Valve shows three key advantages:

  • Simpler implantation: A shorter learning curve for doctors, so more centers can perform TAVI reliably.
  • Fewer pacemakers: Higher implant depth (enabled by the view) lowers the risk of damage to heart conduction pathways.
  • Less PVL: Better positioning means the valve seals more tightly against the aortic root.

Who Should (and Shouldn’t) Use It?

The technique is ideal for patients at high risk of conduction problems—like those with a short membranous septum, calcification in the LVOT (especially below the NCC), or severe mitral annular calcification. A baseline right bundle branch block also makes someone a good candidate.

But it’s not for everyone: People with a bicuspid aortic valve (a common heart defect) or whose anatomy requires extreme C-arm angles (right anterior oblique/caudal) should avoid it.

A Win for China’s TAVI Growth

The cusp-overlap technique isn’t new—used worldwide for self-expanding valves—but its adaptation for the Venus A-Valve is a big step for China’s domestic TAVI programs. By making implantation simpler and more accurate, it could help more patients access life-saving care while reducing complications.

Mi Chen (Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, and University Hospital of Zurich) and Li-Zhong Sun (Beijing Anzhen Hospital) led the research on this technique, published in the Chinese Medical Journal in 2021. Their work builds on global TAVI advances while tailoring solutions to China’s unique device landscape.

doi:10.1097/CM9.0000000000001405

Was this helpful?

0 / 0