According to a report by the U.S. Organ Procurement and Transplantation Network and the Scientific Registry of Transplant Recipient, 1,846 repeat kidney transplants were performed in 2005, up 40 percent from a decade earlier. About 20 percent of those on the kidney transplant waiting list have been transplanted before.

Physicians are trying to figure out why transplanted kidneys don't last longer and what can be done to increase their life span.

This article originally appeared in the March 2008 issue of Kidney Transplant Today.