Tissue Engineered Vessels and Valve constructed with Autologous Bone Marrow Cells Its Clinical Applications and Evaluations

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Prosthetic and bioprosthetic materials currently in use lack growth potential and therefore must be repeatedly replaced in pediatric cardiovascular patients as they grow. Tissue engineering is a new discipline that offers the potential for creating replacement structures from autologous cells and biodegradable scaffolds. In May 2000, we initiated clinical application of tissue-engineered vascular autografts (TEVAs) seeded with cultured cells. However, cell culturing is time-consuming, and xenoserum must be used. To overcome these disadvantages, we began to use bone marrow cells, readily available on the day of surgery, as a cell source.Since September 2001, 44 patients had a cardiothoracic operation using TEVAs seeded with autologous bone marrow cells. Three to 10 mL/kg specimen of bone marrow was aspirated with the patient under general anesthesia before the skin incision. These cells were seeded onto the absorbable scaffold before implantation. This scaffold was composed of a copolym … More er of P (CL/LA) which degrades by hydrolysis. PLLA or PGA woven fabric were used for reinforcement of the scaffolds. Twenty-six tissue-engineered conduits and 19 tissue-engineered patches were used for the repair of congenital heart defects. Patients who had undergone this method had a catheterization study, CT scan, or both for the evaluation after the operation. Four late deaths due to the heart failure with or without multiple organ failure or brain bleeding in this series; these were unrelated to the TEVAs function. A few patient required PTA for the tubular graft-stenosis with pressure gradient and / or collaterals, and four patients for the stenosis of the tissue-engineered patch. However, this tissue-engineering approach may provide an important alternative to the use of prosthetic materials in the field of pediatric cardiovascular surgery. As it utilizes living autologous living tissue, this newly developed vascular structure may have the potential to achieve "auto-tissue repair" for the children with congenital heart defects. However, this approach is still in its infancy, further experimental studies to resolve the problems presented, and longer follow-up in patients are necessary to confirm the durability of this approach. Less