brought back from the brink. covid-19 destroying his lungs, but not his spirit, holding on to hope to see his family again. now the rare behind-the-scenes look at a medical marvel. a risky double lung transplant. cameras capturing every step of the way. and inside the operating room. >> my god. very critical right now. >> will leo get his special chance? this special edition of "nightline," "saving leo," will be right back. and get the same fast relief in a delightful chew with pepto bismol chews. does scrubbing grease feel like a workout?

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♪ ♪ this is the harrowing twilight between life and death. but leslie villatoro is a quiet, steely fighter, a solemn pillar of strength who has tirelessidev as doctors said he may never recover from covid.

now her goliath determination and faith have landed them here, desperately awaiting a rare and risky final shot at life. a covid double lung transplant. >> transplant is -- always should be the option of last resort. >> your lungs are pretty badly damaged from the virus. >> reporter: just months ago, honduran immigrant leo castillo was living out his american dream. the 43-year-old fun dad with a zest for life. a practical joker known for his sense of humor. an essential worker construction supplies during the pandemic. always counting down the days when he could be back home with his kids. >> i'd be so excited to see him. seeing his location, oh my gosh, he's going to be home in 30 minutes!

in the fro whi and hither stay d justau with us, you >> reporter: but a couple months into the pandemic, covid ripped through their washington, d.c. home. first leslie's son, then leslie, both with relatively mild symptoms. but then leo got sick. it wasn't long before he was hospitalized, put on a ventilator. >> one day you get a call, he might only have hours to live?

>> reporter: that unwavering faith and tenacity led them to last-chance shot at life i chicago, praying for a double lung transplant. though he's free of covid, the damage to his lungs was done. he'd be only the fourth ever lung transplant patient due to covid in the entire country. >> feeling okay? yeah? you feel like you've gotten stronger in the last few days? yeah? >> reporter: dr. ankit bharat of northwestern memorial hospital spearheading this effort. he was the first ever to try this surgery on a covid patient in the u.s. the thoracic surgeon has done hundreds of lung transplants, but after helplessly watching covid patients die of lung damage, he took a gamble on a 28-year-old paralegal, myra. >> what made myra an ideal

candidate? >> she was far from ideal. we had a big debate about myra. should we be pursuing transplant without knowing if it's going to work? >> reporter: myra had been an active runner who loved to travel, loved her dogs, loved her life. >> you had to risk a patient's life? >> yeah. >> you had to risk your team's standing? >> yeah. >> risking your own reputation. what made you decide, we're going to try it anyway? >> it was a tough decision. she in many ways reminded me of my family. it was that sense of despair. you'd see her in the icu all swollen. now, there was tremendous risk. if she had not survived, that could potentially be the end of transplants for covid. but we just leveraged everything we had, you know, to give her that chance. >> reporter: the surgeon's gamble paid off. >> i wish i wasn't the first. but since i am, i feel like i have more of a duty to remain alive, to give hope. i do know that i'm here for a purpose.

>> reporter: her newfound purpose now giving hope to leslie. >> leslie was so fierce, so committed to helping leo, she would not let leo fail. >> what is it worth to that person, to that family? you ask the patient, ask the family, they would do everything. >> reporter: leslie moved into a friend's house in chicago, leaving her kids with grandma in d.c., commuting two hours each o.y to

because leo's case so is dire, he's at the top of northwestern's transplant list. it could happen at any minute. to keep him motivated, dr. bharat makes him a promise. >> what's your favorite food? >> burgers. >> oh, the burgers, okay. after the transplant, we can get you to eat and drink, that's my promise. >> reporter: while leo waited for new lungs in chicago, his heart was back home in d.c. his teenaged daughters gabby and camilla facetiming as much as possible. >> i wasn't used to seeing him with all that stuff he had. because it looked like he couldn't even move.

he looked uncomfortable. >> what was the hardest part for you? >> i mean, i felt alone. you know, my dad brought happiness into my life. so it was like, him gone and my oo it was just a lot. >> reporter: just six days after leo was listed for transplant -- there's word of a potential donor. >> they're heading out to take a look at the lungs and give a thumbs up if everything looks fine. >> reporter: if the donor lungs aren't viable, the entire surgery has to be called off. dr. bharat waits for the crucial update from the procurement team. >> every day you're praying there would be a perfect lung that would come for leo. time is of the essence. >> i have to take this phone call. this is from the donor hospital. >> lung is fine. >> okay, great. can you please send me some pictures? >> yes, sir. >> great, all right.

that's great. you know, so the lungs are >> reporter: suddenly it's go time. dr. bharat immediately heads to leo's room with the life-changing news. >> today is the day. you excited? your lungs look great. so this is it. all right? >> the operation will last about 10 to 12 hours. >> reporter: leslie only has a >> reporter: leslie only has a few minutes before parting with

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>> performing a double lung transplant on a covid patient is very complex. we just discovered his heart is really weak and struggling because of the lung failure. we'll connect the valve and everything -- >> i grew up in india. i wanted to be an air force pilot. but we had a family event that was personal, and that turned me to medicine. >> you lost a brother, i understand? >> i was 11, he was 9. he had a traumatic brain injury. and you're all in a state of shock. but there were a number of talented physicians and surgeons

who kept him alive for two or three days. it gave us time, a little bit of hope. that he may survive. for me as his older brother, it gave me time to sit by his bedside and apologize for some of the big brother things i may have done to him. >> do you think he would be proud of you today? >> i hope so. >> ready? going slow and deliberate because these patients tend to have a lot of bleeding. you almost never see this severe scar tissue. >> reporter: what you're about to see is graphic. back at the donor hospital, leo's new lungs are removed from the deceased donor. they have to go into leo'sthey'a >> they're taking off now.

>> reporter: with the new lungs en route, the old ones are creating major problems far worse than expected. >> i don't know what the [ bleep ] is going on. >> did you ever worry that you'd lose him? >> reporter: as dr. bharat pushes forward, the donor lungs arrive. n have just 3 1 hrs before the lungs could go south. as the team works to remove leo's old left lung, he starts to bleed significantly. >> can you pack that? that's very stressful, man. he might die on the [ bleep ]

table. >> reporter: despite the massive blood loss, doctors are able to remove the lung. >> okay, can i get the left lung? between the new left lung and leo's old lung is staggering. >> see how pink and nice these lungs look? this is what we are about to implant. okay. >> reporter: leo's new left lung helps to stabilize his body. as the surgical team now hurries to remove and replace his right lung. >> swab the right side, please. he's very critical right now.e o difficult dissection. this is terrible-looking lungs, my god. it's like a bomb went on. we're about to start the right lung implant.

>> as soon as the second lung went in, everything started to get better. his heart is contracting better. all the bleeding stopped. >> okay, go ahead, inflate this lung. beautiful. beautiful lung. >> what is that like to you, to see the lungs inflate in the new recipient? >> it literally is so stunning to see them inflate and deflate, see the patients pink up, it's things. that was one of the best feelings to say, okay, we did this, and he's going to be okay now. >> thank you. this was not easy, man. thank you for getting him through. >> reporter: four days after

leo's surgery, a special visit from a new friend, myra ramirez, the first post-covid patient to receive new lungs. >> what's it like watching leo struggle back? you must see yourself in him. >> it's really sad. he's going through a lot. i hope he keeps his mind healthy and positive. it takes a lot of mental strength tto go through this. >> reporter: it takes grit to learn to walk again. but leo still has miles to go in his rehab. the biggest fear? chronic rejection. >> 40% of patients can experience that in five years. the good news about that is only 10% to 15% experience the most severe form of chronic rejection, to the point they

need a retransplant. >> reporter: nearly four months after the transplant, he's more sivehan ever. >> how much do you want to go and be with your wife and beautiful daughters again? >> when he comes back home, i'll say i love you and hug him really tight, because i miss him so much. like, i don't know. so many emotions, i can't explain it. >> reporter: leo will spend six more months in chicago to remain under dr. bharat's care. >> oh, look at that, hello, how are you doing? >> reporter: in the meantime, dr. bharat makes good on that pretransplant promise. >> you said you want to eat a hamburger when you get better,

so here's a hamburger for you. is it good? all right. >> i want to say thank you. you're the best. you are the best. and my lord is the number one, and you're the number two. >> you're a hero. and yeah, i appreciate you for saved, among hundreds of thousands, providing endless reasons for hope. >> i make a new life because my life has started when i transplant. i started my life. i am happy.

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leo is now growing stronger at home, exercising with his new friend myra.

and today, behind the wheel for the first time, practicing to get back in his truck. dr. bharat has now performed 12 transplaans d advises other hos how to help patients like leo. california phones offers free specialized phones... like cordless phones. - ( phone ringing ) - big button, and volume-enhanced phones. get details on this state program. visit right now or call during business hours.