A tissue engineered vein graft – proof of concept

There was a very interesting report in the Lancet this past week from the Sahlgrenska University Hospital in Gothenburg in Sweden by Michael Olausson and colleagues describing the successful treatment of a ten year old girl with an extrahepatic portal vein obstruction. A 9cm length of an iliac vein from a deceased organ donor was decellularised and subsequently recellularised with endothelial cells and smooth muscle cells. These had been differentiated from bone marrow stem cells from the patient and stimulated with a variety of growth factors. Having obtained the stem cells to repopulate the decellularised venous matrix, the graft was maintained in bioreactor culture for two weeks before being used for surgery.

A vein was needed for a bypass between the superior mesenteric vein and the intrahapatic left portal vein, and it was felt that the internal jugular vein was not long enough. The engineered vein graft was implanted successfully but one year later there was obstruction and so a further tissue engineered vein graft was prepared, again using the girls own stem cells, and was used to lengthen the existing graft after relieving the obstruction as it passed through the mesocolon.

To date the patient has restored portal circulation, improved physical and mental function and no antiendothelial cell antibodies have been detected. No immunosuppression is being used. This is a very well documented and carefully planned procedure which will not have a great deal of common usage but it does help to set the stage for the future in the growing field of tissue engineering.