LA JOLLA (CBS 8) - UCSD's Sulpizio Cardiovascular Center is a world leader in a lifesaving surgery called Pulmonary Thromboendarterectomy.
The procedure is unique because the patient is actually taken off life support for 20 minutes; not once but twice.
Jeff Eckhoff, 57, and his wife, Gayle, will never forget that day on their Oklahoma cattle ranch in 2010 when a cow charged at Jeff by surprise.
"The mama cow really didn't care for me to be where I was at that time, and the mama cow pretty much wanted to change my zip code," Jeff joked.
He was thrown into a fence and injured his leg.
"I started having trouble breathing about seven months later," Jeff recalled. "It's like you're just running out of air."
For two years, Jeff's condition was misdiagnosed buy doctors in Oklahoma as asthma or allergies.
In fact, blood clots from Jeff's legs had traveled through his blood stream and became trapped in his lungs, blocking his breathing.
It happens to about 25,000 people every year in the United States.
"These patients have gone for years not being able to breathe. You and I can't imagine what it feels like not be able to breathe because we take it for granted," said Dr. Michael Madani, a surgeon at UCSD's Sulpizio Cardiovascular Center in La Jolla.
Dr. Madani operated on Jeff last week to remove the clots in his lungs.
The expert team at UCSD has successfully competed more than 3,000 of these procedures, according to the hospital.
"The first thing we're going to do is stop his heart," said Dr. Madani , as video cameras rolled during the surgery.
Jeff was hooked up to a heart-lung bypass machine, which cooled his body temperature to 65 degrees.
"If you are cold and if your organs are cold, then they don't require much oxygen if they're not active," Dr. Madani said.
To remove the clots, there can be no blood circulation so the operating room doctors have to turn off the bypass machine.
"So for all practical purposes, there is no blood circulation in the body," said Dr. Madani. "For all practical purposes, there is no activity in the body while this happens."
Jeff's heart rate was flat-lined for 20 minutes for each lung. Technically speaking, he was dead.
"The cells are actually alive. They're just not active. They're just sitting there but not doing anything," said Madani.
During the surgery, blood clots and scar tissue are carefully removed from the lung arteries. The clots branch off into tiny branches inside the lungs.
One week after surgery, Jeff was sitting up and recovering. His lung capacity was greatly improved.
Jeff says he doesn't remember anything about the surgery, when he technically died two times.
Blood clots on the lungs can be caused by a leg injury or inactivity in the legs.
Symptoms include shortness of breath and heavy breathing.