At 43, Leo Castillo was loving life, an active and healthy father and husband with a sense of humor.
In the spring of 2020, COVID-19 ripped through his household. By May, Castillo wound up in the hospital and was put on a ventilator.
Though free of COVID, the virus essentially destroyed his lungs. The organs simply couldn't recover.
A rare and risky double lung transplant turned out to be his only hope for survival.
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"Transplant should always be the option of last resort," said Dr. Ankit Bharat, a thoracic surgeon at Northwestern Memorial Hospital in Chicago.
Bharat was the first surgeon to perform a double lung transplant on a coronavirus patient in the U.S. Before, only a few other COVID-19 survivors, in China and Europe, have received lung transplants.
Northwestern Medicine said they have done more of these procedures than any other American hospital.
Just six days after Castillo was listed for transplant, Northwestern found a donor.
After Bharat performed the harrowing surgery, Castillo survived but is still not out of the woods. He's in the middle of a long, brutal recovery.
"I want to say thank you. You are the best, you are the best," Castillo told Bharat.
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Castillo is one of 12 COVID survivors who received a double lung transplant from Bharat. He's collaborated with hospitals throughout the country, in total contributing to 50 of these life-saving procedures.