Animal to human transplant - 28th January 2022

Surgeons in the US have successfully implanted a heart from a genetically modified pig in a 57 year old man. 

The historic procedure took place at the University of Maryland Medical School and represents a major milestone in animal to human transplantation.  It’s hoped that this’ll  be a first step in solving the chronic shortage of organ donations.  

Surgeon Bartley Griffith performed the surgery.

Bartley Griffith: "The driver for all this was to provide an opportunity for patients with end-stage heart disease, who could not either qualify or just didn't get a heart in time, to treat their pretty poor heart function with a transplant."

The patient David Bennett had been deemed ineligible for a human transplant, a decision often taken when the patient has poor underlying health.  Post surgery he’s now recovering well but the final prognosis is as yet uncertain.  

Muhammad Mohiuddin is the director of the cardiac xenotransplant program at the University of Maryland Medical School. 

Muhammad Mohiuddin: "We are all very excited to see this pig heart beating in this human. That pig heart has performed so far very well even beyond our expectations. We have not seen any signs of rejection."

The donor pig heart came from a herd that had undergone genetic editing procedures. Three genes that have led to rejection of porcine organs previously were knocked out as was a gene that leads to excess growth of pig heart tissue. A further 6 human genes responsible for human acceptance were edited into the genome. 

Pigs make ideal donors because of their size, their rapid growth and large litters.

Muhammad Mohiuddin believes this transplantation of genetically modified organs will help change the outcome for the thousands of patients who die every year before receiving a transplant.

Muhammad Mohiuddin: "We'll have these organs available, we can, you know, we have the technique of genetically modifying. So, if there's more tweaking required for modifying the genes, we will be able to do that, and you know, can customise, basically, the heart for all the organs for the patient."