HEALTH: A man dies after receiving a genetically modified pig heart.

David Ben­nett, who suf­fered from ter­mi­nal heart dis­ease, sur­vived for two months after the oper­a­tion in the Unit­ed States.

But his con­di­tion began to dete­ri­o­rate sev­er­al days ago, his doc­tors in Bal­ti­more said, and the 57-year-old died on March 8.

Mr. Ben­nett knew the risks asso­ci­at­ed with the surgery, acknowl­edg­ing before the pro­ce­dure that it was “a shot in the dark.”

Doc­tors at the Uni­ver­si­ty of Mary­land Med­ical Cen­ter obtained a spe­cial waiv­er from the U.S. med­ical reg­u­la­tor to per­form the pro­ce­dure, on the grounds that Mr. Ben­nett — who was not eli­gi­ble for a human trans­plant — would oth­er­wise have died.

He had already been bedrid­den for six weeks pri­or to the oper­a­tion, attached to a machine that kept him alive.

Ben­nett under­went the surgery on Jan. 7, and doc­tors say that in the weeks that fol­lowed, he spent time with his fam­i­ly, watched the Super Bowl and talked about want­i­ng to go home with his dog, Lucky.

But his con­di­tion dete­ri­o­rat­ed, leav­ing doc­tors “dev­as­tat­ed.”

“He turned out to be a brave and noble patient who fought to the end,” sur­geon Bart­ley Grif­fith, who per­formed the trans­plant, said in a state­ment released by the hospital.

But Ben­net­t’s son, David Jr, said he hoped his father’s trans­plant would be “the begin­ning of hope, not the end,” accord­ing to the AP news agency.

“We are grate­ful for every ground­break­ing moment, every crazy dream, every sleep­less night that con­tributed to this his­toric effort,” he added.

Dr. Grif­fith pre­vi­ous­ly said the surgery would bring the world “one step clos­er to solv­ing the organ short­age cri­sis.” Cur­rent­ly, 17 peo­ple die every day in the Unit­ed States while wait­ing for a trans­plant, and more than 100,000 are believed to be on the wait­ing list.

The pos­si­bil­i­ty of using ani­mal organs for so-called xeno­trans­plan­ta­tion to meet the demand has long been con­sid­ered, and the use of pig heart valves is already common.

In Octo­ber 2021, sur­geons in New York announced that they had suc­cess­ful­ly trans­plant­ed a pig kid­ney into a per­son. At the time, the oper­a­tion was the most advanced exper­i­ment in the field to date. How­ev­er, the recip­i­ent on this occa­sion was brain dead with no hope of recovery.

The biggest obsta­cle to the use of organs from anoth­er species is “hyper­a­cute rejec­tion”. The body sees the tis­sue as so for­eign that it begins to kill the donat­ed organ with­in minutes.

The hope was that the 10 genet­ic changes made to the pig meant that its organs would be accept­able to the human body.

It was a ner­vous moment when the heart went in, but there was no hyper­a­cute rejec­tion and that mon­u­men­tal bar­ri­er had been breached.

When I spoke to the sur­gi­cal team a month after the surgery, they told me that there was still no sign of rejec­tion and that the donat­ed heart was work­ing like a “Fer­rari engine.” But they cau­tioned that he him­self was still fragile.

Exact­ly what has hap­pened since and the pre­cise cause of Mr. Ben­net­t’s death is unclear.