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

Area of Science:

• Biomedical Engineering
• Regenerative Medicine
• Vascular Surgery

Background:

• Patient-specific, 3D printed, tissue-engineered vascular grafts (3DTEVGs) are designed for optimized hemodynamic performance and growth accommodation.
• Pulmonary artery reconstruction often requires grafts that can adapt to patient growth.

Purpose of the Study:

• To evaluate the growth outcomes of 3DTEVGs compared to standard grafts in a porcine model for pulmonary artery reconstruction.

Main Methods:

• Four-dimensional flow magnetic resonance imaging (4D flow MRI) was used in 8 porcine models.
• Four pigs received 3DTEVGs designed with computational fluid dynamics, while four received standard polytetrafluoroethylene (PTFE) grafts as controls.
• Grafts were evaluated postoperatively via MRI and histology after 10 weeks.

Main Results:

• All pigs survived with patent grafts. 3DTEVGs exhibited positive inner diameter changes (0.47 ± 2.31 mm) versus negative changes in controls (-4.61 ± 2.15 mm; P = .018).
• Mean main pulmonary artery wall shear stress was significantly lower in 3DTEVGs (7.12 ± 4.21 Pa) compared to controls (18.15 ± 8.37 Pa; P = .0396).
• Histology of 3DTEVGs revealed a single endothelial cell layer, organized smooth muscle, and collagen deposition with 21.37% ± 20.46% scaffold remaining.

Conclusions:

• Patient-specific 3DTEVGs demonstrated excellent anatomic fit and maintained favorable flow dynamics.
• These grafts promoted appropriate neovessel formation, indicating successful tissue integration and growth potential.