[Clinical results of tissue-engineered vascular autografts seeded with autologous bone marrow cells].

UNLABELLED: In May 2000 we initiated clinical application of tissue-engineered (TE) vascular grafts seeded with cultured cells. However, cell culturing is time-consuming and xeno-serum must be used. To overcome these disadvantages, we started to use bone marrow cells (BMCs), readily available on the day of surgery, as a cell source. The aim of this study was to assess the safety and feasibility of this technique for creating pulmonary arteries.

METHODS

Since August 2000, TE grafts seeded with autologous BMCs have been implanted in 42 patients. Bone marrow (5 ml/kg) was aspirated under general anesthesia prior to the skin incision. The polymer tube serving as a scaffold for the cells was composed of a co-polymer of 1-lactide and epsilon-caprolactone (50:50). This co-polymer is degraded by hydrolysis. The matrix is >80% porous and the diameter of each pore is 100-200 microm. Polyglycolic acid woven fabric with a thickness of 0.5 mm was used for reinforcement. Twenty-three TE conduits (TCPC grafts) and 19 TE patches were used for the repair of congenital heart defects. The patients' ages ranged from 1 to 24 years (median, 5.5 years). All patients underwent a catheterization study and/or computed tomography (CT) scans for evaluation after surgery. The patients received anticoagulation therapy for 3 to 6 months after surgery.

RESULTS

Mean follow-up after surgery was 584 days (maximum 42 months). There were no lethal complications such as thrombosis or aneurysmal rupture. One late death at 3 months after TCPC was noted in a hypoplastic left heart syndrome patient, which was unrelated to the TE graft. There was no evidence of aneurysm formation on cineangiography or CT.

CONCLUSIONS

Biodegradable conduits or pulmonary vessel patches seeded with autologous BMCs showed normal function (good patency up to maximum follow-up of 38 months). As living tissues, these vessels may have the potential for growth, repair, and remodeling. The TE approach may provide an important alternative to the use of prosthetic materials in the field of pediatric cardiovascular surgery. Longer follow-up is necessary to confirm the feasibility of this approach.