Stem-cell-based, tissue engineered tracheal replacement in a child: a 2-year follow-up study

http://www.sciencedirect.com.lib-ezproxy.tamu.edu:2048/science/article/pii/S0140673612607375

Tissue engineered transplants relaying on the repopulation of the stem cells seems to be feasible. In this article, a 12-year-old boy, Ciaran, receives a stem-cell-based tracheal replacement with a 2-year follow-up.

Ciaran was born with long-segment congenital tracheal stenosis and pulmonary sling which caused the narrowing of the windpipe and difficulties of breathing. His airway was maintained open using a metal stent; however, it later eroded into the aorta causing bleeding. Another surgery was performed on the damage part of trachea replacing it with a donor trachea. In 2009, the stent again eroded into the aorta causing severe bleeding. In march 2012, Prof. Martin Elliot, director of the national service for severe tracheal disease in children at GOSH, along with his team replaced the Ciaran’s trachea with an adult-donor windpipe laced with the Ciaran’s own stem cells. Additional cytokines were injected to encourage angiogenesis and chondrogenesis-the growth and the differentiation of the cells within the transplanted trachea. Ciaran was also given granulocyte colony-stimulating factors (G-CSF) to induce the cell growth.

The transplantation was successful. After the two-year follow-up, important findings were reported:

Within one week after surgery, the graft revascularized.  

 

 A strong neutrophil response was noted locally for the first 8 weeks after surgery, which generated luminal DNA neutrophil extracellular traps’ (part of the immune response to infections)
 

The epithelium layer was not evident until the first year and the graft did not have biomechanical strength until 18 months, but no medical intervention was required since then.

 Chest CT scan and ventilation-perfusion scanwere normal at 18 months after the surgery.
 

Ciaran had grown 11 cm in height in two years after surgery. 

 

Ciaran’s windpipe allows him to breathe normally, but has not yet achieved normal rigidity. It is expected that the body’s natural tissue repair mechanisms will continue strengthening his trachea over time.

The follow-up of the first pediatric, stem-cell-based, tissue engineered transplant proves its feasibility, but also highlights the needs for further research. I chose this article because I am very interested in the transplantation of new organs into patients. It is amazing to be able to observe how the patient’s body responds to the new organ. This is a very fascinating branch of the biomedical engineering.

References: Elliott M. J., et al. Stem-cell-based, tissue engineered tracheal replacement in a child: a 2-year follow-up study. The Lancet, Early Online Publication, 26 July 2012 doi:10.1016/S0140-6736(12)60737-5