A combined Additive Layer Manufacturing / Indirect Replication method to prototype 3D vascular-like structures of soft tissue and endocrine organs

We describe an innovative methodology combining Additive Layer Manufacturing (ALM) and indirect replication to reconstruct reticular-like, three-dimensional (3D) structures mimicking the vascular network of soft tissue and endocrine organs. Using a fractal-like algorithm capable of modelling the intraparenchymal vascular distribution of these viscera, single intraglandular branches of the human thyroid arteries were prototyped with synthetic resin, based on the algorithmic standard to layer (STL) output and ALM techniques. Satisfactory dimensional accuracy was obtained for these models, which were used as masters to evaluate protocols for their indirect replication, through both single and double procedures. Additional studies were conducted using casts of the human kidney arteries, obtained by injection / corrosion of the isolated organ. Satisfactory 3D reproduction of the external morphology of the kidney vessels was achieved. We conclude that our approach has the potential to develop up to the reconstruction with biomaterials of an entire, intraparenchymal vascular tree of soft tissue and endocrine organs.