Validity of Customized Branched Tissue Engineered Vascular Graft in a Porcine Model.

Background: Patient-specific, 3-dimensional printed, tissue engineered vascular grafts (3DTEVGs) are manufactured to optimize hemodynamic performance and to accommodate growth. We evaluate growth outcomes of 3DTEVGs compared with standard grafts for pulmonary artery reconstruction in porcine models.

Methods: Magnetic resonance imaging (MRI) with 4-dimensional flow data was acquired in porcine models (n = 8). 3DTEVGs guided in design by computational flow dynamics were implanted (n = 4), with polytetrafluorethylene grafts used as controls (n = 4). Postoperative MRI and histologic features of explanted grafts were evaluated after 10 weeks.

Results: All pigs survived, with evidence of patent grafts on postoperative MRI. Graft inner diameter changes were 0.47 ± 2.31 mm in 3DTEVGs and -4.61 ± 2.15 mm in controls ( = .018). Mean main pulmonary artery wall shear stress was significantly lower in 3DTEVGs (7.12 ± 4.21 Pa) than in controls (18.15 ± 8.37 Pa;  = .0396). Histologic evaluation of 3DTEVGs showed a single layer of endothelial cells, an organized smooth muscle layer, and collagen deposition with a remaining scaffold area of 21.37% ± 20.46%.

Conclusions: Our patient-specific 3DTEVGs demonstrated optimal anatomic fit while maintaining ideal flow dynamics and promoting appropriate neovessel formation.