(CNN) -- When Manuel Reyna developed a deadly kidney disease, his sister, Florinda Gotcher, didn't hesitate to give him one of her kidneys. When she found out they were a match, she cried.
"She was so happy," remembers Gotcher's daughter, Melinda Williams. "She was overwhelmed that she was able to save her brother's life."
Williams said her mother didn't worry about the risks of surgery. Statistically, kidney donor surgery is considered to be very safe: in 2010, the year before Gotcher's surgery, 6,276 people donated a kidney, and none of them died within 30 days of the surgery.
Her laparoscopic surgery went well, but about 30 minutes afterwards in the recovery room, she took a mysterious turn for the worse.
"She just took a deep breath and her eyes got real huge and then she fell back down and started breathing really, really bad," Williams says.
Surgeons at University Medical Center in Lubbock, Texas, rushed Gotcher back into the operating room. Once they opened her up again, they saw something horrible had happened: there was a pool of blood in her abdomen. Gotcher, 41 and the mother of four, had died from a massive and sudden bleed.
"My world just fell apart and my heart was torn to pieces," Williams says of her mother's sudden death."They told us, 'We couldn't save her. Sorry, we did everything we possibly could, but there's nothing we could do.'"
No specific warning on surgical device
Williams would later learn her mother's death wasn't a freak accident -- it had happened to other patients before.
To remove a kidney for donation, surgeons have to cut the renal artery They then have to close it back up again, or the patient would bleed to death.
There are various ways to close the artery. Many surgeons use staples, but some use tiny surgical clips to hold it closed.
These clips are considered safe to use in many types of surgeries, but not laparoscopic kidney donor surgeries. In donors surgeries, surgeons leave only a tiny stump of renal artery, and the clips can slip off. That's what happened to Gotcher: when doctors opened her back up, they found the clips had slipped off the stump and were floating in a pool of blood in her abdomen.
Before Gotcher's death, four other kidney donors had died when these clips were used: one in 2001 in the United States, one each in Singapore and Israel in 2005, and another in the U.S. in 2008. At least 12 others have suffered injuries.
Starting in 2004, transplant surgeons, such as Dr. Amy Friedman, began raising concerns about using clips in kidney donors, sending letters to the U.S. Food and Drug Administration and making presentations at transplant conferences and publishing articles in medical journals.
When she heard about Gotcher's death in 2011, Friedman said she was "devastated."
"We were just in shock and deep sorrow to learn that our actions thus far and our efforts to try to stop the practice had been ineffective," says Friedman, director of transplant services at Upstate Medical University in Syracuse, New York.
Friedman said there should be a warning label right on the clips.
"I think it would be great to say, 'Don't use on a kidney donor,'" she says.
The clip packaging does have a warning symbol advising doctors to look at the instructions that come with a separate tool used to apply the clips. The instructions, which are typically not kept in operating rooms, state the clips should not be used on kidney donors.
Beginning in 2006, Teleflex, the manufacturer of the clips, sent warning letters alerting hospitals that the clips were "contraindicated" -- or unsafe for use -- in laparoscopic kidney donor surgeries. Hospitals received at least three letters, and some received as many as six.
Officials at University Medical Center, where Gotcher had her surgery, said they received the 2006 letters, but at the time they weren't purchasing the clip. Years later, when they did start purchasing the clips, the letter had been forgotten -- it was one of dozens of letters about various devices and other safety issues the hospital gets every year.
Friedman says the letters didn't go far enough to alert doctors not to use them on kidney donors. For example, they didn't mention that kidney donors had actually died when the clips were used on them.
"It's shocking that it doesn't say that even a single donor died. It's meaningless without saying that," Friedman says.
According to documents obtained by Dr. Friedman through the Freedom of Information Act, in 2007 the FDA called these letters "effective" and "adequate to prevent a reoccurrence of the problem" even though only about half the hospitals acknowledged getting the notification, according to a 2007 audit by the FDA.
After Gotcher's death, the FDA issued a safety notification reminding surgeons that the clips are contraindicated for kidney donor surgeries.
"It comes back to me all at once."
In a statement to CNN, the FDA said the clips, when used correctly, can effectively control bleeding. The agency added that while most transplant surgeons heeded the agency's warning, "despite repeated efforts to communicate this important safety information, some transplant surgeons continue to improperly use these clips. While the FDA can warn against the unsafe use of a medical device, doctors are not prohibited from using cleared or approved devices for an unapproved use within their practice of medicine."
Teleflex, the company that makes these clips, said surgeons have safely and successfully used them in millions of surgical procedures, and that the company believes the transplant community is "well aware" of the warning not to use them in kidney donors.
"A contraindication is a clear, well understood and accepted concept in the medical community that says, 'Do not use this device for this purpose,'" Teleflex wrote in a statement to CNN.
University Medical Center, where Gotcher died, says it wasn't using the clips when it received the warning letter in 2006, and that its system to track warnings was insufficient to alert the hospital when they later purchased clips. They've since put corrective actions in place by hiring an outside company to track and document warnings and recalls.
The hospital settled a lawsuit filed by Gotcher's family for an unspecified sum.
None of this brings back Florinda Gotcher.
"Every time I go to the cemetery it hits me," her daughter says. "It comes back to me all at once."