A nine-way kidney swap, considered to be the longest kidney transplant chain, was performed in San Francisco on Friday.

The doctors from California Pacific Medical Center and the University of California at San Francisco (UCSF) performed 18 surgeries with nine donors and nine recipients between the two hospitals in 36 hours.

Two kidneys were sent from California Pacific to UCSF via a special organ transport service and two kidneys were sent from UCSF to California Pacific for a total of four, 3-mile trips On Friday. Two trips were made Thursday.

Noel Sanchez, spokesman for Donor Network West, said everything went as planned and their team is just getting to transport the very last one.

Over 1 lakh people in the US are waiting for a kidney due to variety of health conditions that causes renal failure. On an average a person in US has to wait for four to five years for a kidney from a deceased person.

However, a computer software program, which was first developed by a former kidney transplant patient at California Pacific, has made kidney transplant chains possible by connecting willing donors with compatible recipients.

People who want to donate a kidney are matched with the potential compatible donors with an assurance that their friend or family member needing a kidney will also be paired with a suitable donor.