Manavitehrani I, Ebrahimi P, Yang I, Daly S, Schindeler A, Saxena A, Little DG, Fletcher DF, Dehghani F, Winlaw DS.
Cardiovasc Eng Technol. 2019 Feb 14. doi: 10.1007/s13239-019-00406-5. [Epub ahead of print] Review.
- This article is a helpful review of current challenges and future directions of the development of optimal conduits for right ventricular outflow tract reconstruction.
Commentary from Dr. Jeremy Herrmann (Indianapolis), section editor of Congenital Heart Surgery Journal Watch: Right ventricular outflow tract reconstruction procedures remain one of the most common congenital cardiac surgical procedure performed in children and adults, though the optimal conduit type remains elusive. Manavitehrani and colleagues provide an excellent comprehensive review about this topic, in which they highlight the inherent limitations and challenges of selecting and/or designing conduits. Few clinical data or summaries are provided, though these are beyond the scope of this paper. The authors review the natural characteristics of pulmonary arterial tissue including its biomechanical properties. The evolution of the current landscape of conduit choices is described along with the relevant limitations of current conduit choices including lack of growth potential and biomechanical differences in implanted native and xeno- or allograft material. The authors look ahead at tissue engineering options including scaffold-based processes with various natural and synthetic biomaterials as well as recent advances in electrospinning, 3D printing, and bioprinting. Newer advancements may allow for replacement of the graft material with native tissue, growth with the patient’s somatic size, and improved compliance. However, these process are challenged of incorporating natural cells for tissue differentiation and how to accurately guide cell behavior. Any of these strategies must provide long-term functional replacement that will be readily functional at the time of implantation. Finally, the authors discuss the role of computational fluid dynamics and modeling in designing and evaluating optimal conduits. Much of the discussion centers around what is currently employed at a few centers for the Fontan procedure, and the extension of this application to RVOT procedures is not difficult to imagine.