A mechanical engineer said lab employees misused a cryogenic tank, causing an accident that damaged thousands of frozen eggs and embryos at a San Francisco fertility clinic.
SAN FRANCISCO (CN) — After emotional testimony by two women whose eggs and embryos were damaged in a fertility clinic mishap, a cryogenic tank maker called its first witness Thursday to dispute claims that a manufacturing defect caused the catastrophe.
Franklin Miller, a mechanical engineering professor from the University of Wisconsin who used to work on cryogenic systems for NASA, testified that Pacific Fertility Center employees are to blame for an accident that prematurely thawed 3,500 frozen eggs and embryos at a San Francisco fertility clinic on March 4, 2018.
“I have the opinion that Pacific Fertility misused the MVE 808 when they unplugged the controller,” Miller said, referring the cryogenic tank’s model number and controller device that monitors liquid nitrogen levels and sends off alerts about tank problems.
Miller was hired by tank manufacturer Chart Inc. to rebut testimony that the accident was caused by a manufacturing flaw.
The clinic’s lab director, Joseph Conaghan, testified last week that he unplugged the tank’s controller device 17 days before the equipment failure. He said the controller was malfunctioning and sending out false alerts about low liquid nitrogen levels.
“When Dr. Conaghan unplugged the controller, what he did was he placed the tissue in Tank 4 at additional risk that none of the tissue in the other tanks in his lab were subject to,” Miller told jurors from the witness stand.
After the controller was unplugged, Conaghan told lab workers to manually monitor the tank’s liquid nitrogen levels with a dipstick each day. Miller said that technique was inadequate because it did not provide 24-7 monitoring, and the tank was no longer connected to an alarm system to warn lab workers about problems. Miller noted that some measurements were missing or backdated in digital logs, suggesting the manual measuring system was not “well implemented.”
He also called attention to the fact that liquid nitrogen levels were recorded in tenths of an inch instead of eighths of an inch, which is how the dipstick measurements work. That discrepancy suggests the staff wasn’t taking accurate measurements, he said.
“I don’t think they were reading the numbers off the stick,” Miller said. “They were sort of guessing or guesstimating.”
Miller further faulted the fertility clinic staff for not immediately moving tissue samples into a backup tank when they discovered the tank’s controller device was malfunctioning on Feb. 15, 2018.
“If the controller was not providing the level of indication on Tank 4, the backup tank should have been put into service,” Miller said.
Miller also attacked theories about the cause of the tank failure posited by the plaintiffs’ expert witness. Mechanical engineer Anand Kasbekar testified on May 24 that the accident resulted from Chart’s use of a weaker weld near a liquid nitrogen inflow pipe, making the tank susceptible to cracking, leaks and failure.
Miller noted that in his 25 years of working with cryogenic systems, he’s never seen one that used a full-penetration weld like the one Kasbekar said should have been used on Chart’s tank. All the tanks he’s worked with used seal welds, he said.
“I’ve never designed a full-penetration weld for a cryogenic vessel,” Miller said.
Miller also rejected Kasbekar’s theory that a defect caused a loss of integrity in the vacuum seal layer that separates the inner and outer walls of the tank. Kasbekar posited that the tank leaked a large amount of liquid nitrogen in 22 hours after it was last checked and before a problem was detected on March 3, 2018.
But Miller said it would be impossible for the tank to leak that much liquid nitrogen in that time span. It would be equivalent to venting 42,000 2-liter bottles of nitrogen gas in 22 hours, he said. The engineering professor further argued that if there were a vacuum seal layer problem, the staff would have noticed clouds of nitrogen fog spewing from the tank, frost forming on the vessel’s outer walls and moisture pooling beneath the tank.
Miller said he believes the tank had a relatively small leak, which caused the bottom layer of the tank, called a “getter,” to fill with nitrogen gas. He predicted that some time between March 3 and March 4, liquid nitrogen levels in the tank fell close to zero. That would cause a rise in pressure that explains why the top of the tank buckled. That is consistent with lab employees’ testimony that they had trouble getting the lid off the tank on March 4, he said.
“There were no signs of vacuum failure, but there were signs of buckling at the top,” Miller said.
After tissue samples were removed from the tank, the container was left open for about three days. A photo from March 6 shows the tank’s inner walls imploded. Miller said this resulted from a rapid depletion of liquid nitrogen that was still sitting in the tank. He believes the implosion that occurred after the tank was taken out of commission is what caused a crack to develop in the weld near a liquid nitrogen inflow pipe. He disputed Kasbekar’s theory that a crack in that weld is what caused the tank failure and implosion.
“If that crack was there before, it would have had a high boil rate,” Miller said of liquid nitrogen inside the tank. “It would have frost and vapor coming out and all kinds of things.”
Earlier Thursday, two plaintiffs testified how the tank failure affected their lives.
Laura Parsell, a 39-year-old Ohio woman who had four embryos with her husband in the tank, described the pain and anguish she felt after trying unsuccessfully to get pregnant using embryos involved in the tank failure.
“It was indescribable and incomprehensible,” Parsell said.
Fighting back tears throughout her testimony, Parsell recalled how the clinic handed her “my two dead babies in a test tube,” which she brought home to Ohio from San Francisco so she could bury them.
Chloe Poynton, a 39-year-old fertility patient, said the trauma of losing her nine frozen eggs in that tank accident has harmed her relationships with friends and made her feel more alone.
“It’s really painful to be at a baby shower celebrating someone else’s family being built and knowing inside you’ll never get that,” Poynton said. “So you start to pull back. You start to isolate.”
The plaintiffs also called Elizabeth Grill, a director of psychological services for reproductive medicine at Cornell University, to the witness stand. Grill testified about the emotional pain each of the five plaintiffs who are suing Chart felt as a result of losing frozen eggs and embryos they worked so hard to cultivate.
“They went from a place of being incredibly proactive to a place of being completely powerless,” Grill said. “They did everything they could to have this material in place when they needed it. Instead of being able to reap the benefits of that proactive feeling, they went to feeling powerless. Instead of being optimistic and hopeful, they’re now in a place of devastation and grief.”
The plaintiffs are suing Chart for product liability and failure to recall the tank’s allegedly defective controller device. The trial involves only five plaintiffs, but it could establish Chart’s liability for the loss of reproductive tissue belonging to hundreds of other people.
Chart recalled its cryogenic storage tanks on April 23, 2018, saying it needed to investigate a “vacuum leak and/or failure which may be due to inadequate adhesion of the composite neck to the aluminum unit.”
The fertility clinic and its owners were also sued for the loss of eggs and embryos, but those claims were sent to private arbitration. Prelude Fertility acquired Pacific Fertility in September 2017, and Prelude’s subsidiary Pacific MSO now manages the San Francisco clinic.
The trial overseen by U.S. Magistrate Judge Jacqueline Scott Corley is expected to continue through June 10.