It took 18 surgeries and 10 people, but the University of California San Francisco and the California Pacific Medical Center have just pulled off an amazing nine-way kidney transplant that took place over two days between two different hospitals.

A total of 10 surgeries were completed involving five donors and five recipients first, followed by a final eight surgeries for four pairs of donors and recipients that recently wrapped up, finished the longest transplant chain of kidneys in one city over a very brief time period, according to an SFGate report.

It took some moving back and forth between hospitals of the kidneys, which was a major logistical challenge. Two of the kidneys were sent from UCSF to California Pacific by way of a special organ transport service, and two of them went from California Pacific to UCSF as doctors scrambled match up kidneys with the correct recipients, as the organs were shuttled over the three miles between the two hospitals on Thursday.

It’s difficult to help those who need a kidney transplant, as the line is long — 101,000 people on the waiting list — and sometimes even when a family member wants to donate, they can’t because they’re not a match. People usually wait four to five years to get a kidney, and some don’t have that long to wait.

However, a new computer software program allows more efficient matching of donors and recipients, which is what made the most recent surgery possible. Basically, a family member might not be able to contribute a kidney to their loved one, but they can give that kidney to someone else who needs it, and in exchange the loved one will get a kidney from a different donor.