A narrative review of esophageal tissue engineering and replacement: where are we?

Long-gap esophageal defects, whether congenital or acquired, are very difficult to manage. Any significant surgical peri-esophageal dissection that is performed to allow for potential stretching of two ends of a defect interrupts the esophageal blood supply and leads to complications such as leak and stricture, even in the youngest, healthiest patients. The term "congenital" applied to these defects refers mainly to long-gap esophageal atresia (LGA). Causes of acquired long-segment esophageal disruption include recurrent leaks and fistulae after primary repair, refractory GERD, caustic ingestions, cancer, and strictures. 5,000-10,000 patients per year in the US require esophageal replacement. Gastric, colonic, and jejunal pull-up surgeries are fraught with high rates of both short and long term complications thus creating a space for a better option. Since the 1970's many groups around the world have been unsuccessfully attempting esophageal replacement with tissue-engineered grafts in various animal models. But, recent advances in these models are now combining novel technologic advances in materials bioscience, stem-cell therapies, and transplantation and are showing increasing promise to human translational application. Transplantation has been heretofore unsuccessful, but given modern improvements in transplant microsurgery and immunosuppressive medications, pioneering trials in animal models are being undertaken now. These rapidly evolving medical innovations will be reviewed here.