Releasable annuloplasty ring insertion--a novel experimental implantation model

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Medical Devices

Background:

• Conventional annuloplasty ring (AR) implantation requires a control group for experimental testing.
• A method for in vivo assessment of AR effects within the same animal is needed to serve as an internal control.

Purpose of the Study:

• To develop and test a reversible AR insertion technique in an ovine model.
• To enable beating heart assessment with and without an AR in the same animal.

Main Methods:

• A novel technique using a releasable annuloplasty ring (AR) with locking and drawstring sutures was developed.
• Radiopaque markers were implanted on the mitral annulus of 12 sheep, and 4-D marker tracking was used with biplane videofluoroscopy.
• AR insertion, data acquisition with the AR in place (Geo-AR), suture release, and data acquisition without the AR (control) were performed.

Main Results:

• The reversible AR implantation and release procedure was successful in all animals.
• Mitral annular area dynamics were significantly reduced with the Geo-AR in place (MAA(max): 6.2 cm², MAA(min): 6.0 cm²) compared to the control state (MAA(max): 9.0 cm², MAA(min): 7.8 cm²).

Conclusions:

• The developed releasable AR implantation method is feasible for in vivo studies.
• This technique allows for direct assessment of AR effects within the same animal, facilitating experimental validation and development of new ARs based on physical criteria.