First human transplantation of a bioengineered airway tissue

Abstract

the sternum veins bears some similarity to the opening of the cranial vault veins, and disconnecting the endotracheal tube just before sternotomy decreases airway pressure. Furthermore, 5 (25%) of our patients had a preexisting right-to-left shunt, again increasing the likelihood of clinically significant VAE. The fact that embolus incidence was higher with the saw compared with the scissors is not straightforward. It would seem that the saw would result in less compression of the bone marrow, thus being less traumatic. One may hypothesize that the vibration caused by the saw action induces microbubble formation such as in agitated saline. This hypothesis was tested by pressing the saw against the closed chest wall, thus testing the effects of the vibrations alone. No emboli were detected. Another explanation might be that the vibrations cause increased small amounts of air entrainment in the open vessels. This hypothesis has not been tested. In summary, our results suggest that VAE during sternotomy is a frequent occur-rence and that the number of emboli is related to the method of sternotomy.

Tracheal Tissue Engineering

“…Recent preliminary clinical studies have shown ECM scaffolds provide a viable option for patients who previously had none [148]. This approach utilizes decellularized human tracheas prepared via a detergent enzymatic method with sodium deoxycholate.…”

“…Decellularized aortic grafts [147], jejunum [148,149,150], bladder [151], and trachea [151,152,153,146] …”

“…However, this biomimetic seeding strategy has had some success in humans, when seeding chondrocytes differentiated from MSCs on the exterior surface and epithelial cells on the interior surface [146]. Other combinations of cells utilized for trachea repair are epithelial cells and fibroblasts [172], endothelial cells and epithelial cells [173], chondrocytes and fibroblasts [136], fibroblasts and muscle cells [148], and bone marrow stromal cell-derived chondrocytes and epithelial cells [152,146]. Walles et al evaluated an even greater number of cell types; seeding chondrocytes, bone marrow-derived smooth muscle cells, bone marrowderived endothelial cells, or respiratory epithelium on a decellularized matrix [150].…”

“…Preliminary clinical studies have employed a decellularized human trachea graft to engineer a living prosthesis [148]. Despite the early clinical success there remain many outstanding questions.…”

“…with excellent short-term results [148]. In this approach, cellular material was removed from a human donor trachea with detergent and enzymatic rinses.…”