A bit more of the story is here http://ihatedialysis.com/forum/index.php?topic=21141.0
The implantable device aims to eradicate that problem. The two-stage system uses a hemofilter to remove toxins from the blood, while applying recent advances in tissue engineering to grow renal tubule cells to provide other biological functions of a healthy kidney. The process relies on the bodys blood pressure to perform filtration without needing pumps or an electrical power supply.