Artist’s rendering showing how a braided, tubular implant could grow in sync with a child’s heart valve. (Credit: Randal McKenzie)

Until now, the use of medical implants in children has been complicated by the fact that fixed-size implants cannot expand in tune with a child’s natural growth. To address this, a team of researchers has developed a growth-accommodating implant designed for use in a cardiac surgical procedure called a valve annuloplasty, which repairs leaking mitral and tricuspid valves in the heart.

The implant is meant to enhance the durability of pediatric heart valve repairs while also accommodating a child’s growth, decreasing the number of heart surgeries a child must endure. Beyond cardiac repair, the team says the tubular, expanding implant used in their proof-of-concept design could also be adapted for a variety of other growth-accommodating implants throughout the body.

To create the degrading core, Karp’s team recommended the use of an extra-stiff, biocompatible polymer that begins to erode on its surface following implantation. The polymer itself is made of components that already exist in the human body. The proprietary design of the braided sleeve doesn’t just share resemblance to a Chinese finger trap but also to an organic structure engineered by nature itself.

Based on the team’s promising experiments in animal models, the biomedical device company CryoLife Inc., is currently doing pre-clinical research to develop the concept into a growth-accommodating annuloplasty ring implant for pediatric heart valve repair in humans.

The researchers say the concept could be adapted for many different clinical applications, with exciting potential to be converted into an actively — rather than a passively — elongating structure that could act as a tissue scaffold encouraging growth.