Tissue Engineered Breast Reconstruction – How Close Are We?

The authors attempted to produce large volumes of vascularized, stable, autologous adipose tissue for breast reconstruction. The ability to produce vascularized adipose tissue of sufficient volume for breast reconstruction by tissue engineering techniques could revolutionize reconstructive surgery. Clinical trials of human adipose tissue engineering require many issues to be addressed in animal models. These include the reliable production of adipose tissue in large volumes, maintenance of vascularization, long-term tissue stability, and methods for non-invasive monitoring of tissue growth. Mouse, rat, and pig models for adipose tissue engineering were developed in and have been used to resolve these issues.

Numerous studies in small animals were performed to identify the requirements for reliable adipose tissue production, using techniques directly applicable to humans. Long-term murine studies (up to 18 months) were then performed to test the stability of the volume, vascularization, and phenotype of the adipose tissue produced, and to identify the best techniques for use in a large animal (pig) model. Various medical imaging modalities were then tested for their ability to monitor tissue growth and vascularization non-invasively within the large volume (78 ml) tissue constructs.

Small animal studies have shown that a combination of vascular supply, local tissue source, suitable matrix, and appropriate anatomical location lead to reliable adipose tissue production. Long-term murine studies showed excellent adipose tissue growth to the limits of the tissue engineering chambers, and this new tissue was maintained in studies for up to 18months. The porcine model showed the production of large volumes of vascularized tissue (78 ml) that could be transferred on its pedicle. The flaps maintained their volume for up to 20 weeks, and growth could be monitored non-invasively by the use of magnetic resonance imaging (MRI).

Human adipose tissue engineering for breast construction is promising. Issues such as the ideal chamber configuration are still to be resolved, but this research moves tissue engineered breast reconstruction in humans closer to being a reality.