Doctors at a San Francisco hospital began a final round of kidney transplant surgeries on Friday in a rare organ-transplant chain from living donors that will result in healthy kidneys going to six sick people.

The first three pairs of donors and recipients were recovering after Thursday’s operations at California Pacific Medical Center, said hospital spokesman Dean Fryer.

“All three went very well, very smoothly with no complications at all,” he said, adding that donors typically can be released in two to three days and recipients in three to five days. “The patients are getting some much-deserved rest.”

The next round of three transplant operations began at 7:30 a.m. on Friday, he said.

Among those recovering from Thursday’s surgery was Zully Broussard, 55, of Sacramento, California, a so-called altruistic donor who had triggered the domino effect involving 12 people.

Broussard, whose son and husband both died of cancer, offered to donate a kidney to a friend, but the friend ultimately had to use another donor, according to hospital officials.

Broussard was still willing to donate, so she was matched with a man she did not know from Benicia, California. That man's sister-in-law, who was not a match for him, agreed to donate her kidney to a Fresno woman, while her son, in turn, would be a donor for another woman, and so on.

This was the largest kidney swap in the 44-year history of California Pacific's transplant center. In 2011, the hospital became the state's first to do a five-way swap, Fryer said.