Anthony Atala and collagues from North Carolina's Wake Forest University had successfully transplanted bladders grown in a lab from the patients' own cells.
They took a bladder biopsy from each patient and isolated muscle cells and special bladder cells called urothelial cells, which they grew in the lab.
The cells were then placed onto a specially designed bladder-shaped scaffold and left to grow for seven to eight weeks.
The researchers surgically attached the engineered bladder to the patient's own bladder and followed progress for up to five years.