David Spencer holds a REBOA outside of the Prytime Medical Devices, Inc. Texas Intrepid Ventures office.
David Spencer holds an ER-REBOA catheter outside of the officies of Prytime Medical Devices. Credit: Bonnie Arbittier / San Antonio Report

Pointing to a wall of photographs, David Spencer tells the stories of each of the survivors — a Houston man who was split down the middle after being ejected from the seat of his motorcycle and landing on a fire hydrant, a Kahnawake Mohawk man shot in the pelvis, and a Jehovah’s Witnesses mother whose daughter received a life-saving alternative to a religion-prohibited blood transfusion.

They all survived near-certain death thanks to the ER-REBOA, a long catheter that enters through the thigh with a balloon at the end. When inflated, the balloon closes the aorta, preventing the patient from bleeding out and keeping blood flowing to the brain and lungs.

Spencer’s company Prytime Medical Devices didn’t originally envision the REBOA, which stands for Resuscitative Endovascular Balloon Occlusion of the Aorta, for the civilian world. It started as a research and development project of the U.S. Department of Defense as the military looked to save lives of troops injured by an increasingly common weapon in the perpetual Iraq and Afghanistan Wars — improvised explosive devices.

The REBOA is often referred to as an internal tourniquet because of its effectiveness at preventing internal bleeding, especially in the torso, chest, and pelvis. Before the device’s invention, a patient with serious internal bleeding would need their chest cavity opened via a procedure called thoracotomy, which had a low rate of survival.

Now the REBOA has been used in more than 350 hospitals and 160 trauma centers throughout North America and Western Europe.


Spencer’s winding path to the REBOA has taken him from average engineering student to maintaining software for U.S. Air Force planes to starting his own software firm. But if you ask Spencer why he traded the relatively safe environs of software engineering for the riskier and slower-to-progress world of medical devices, he’d take you back to the Great Depression when his uncle Merle was struck with illness as a child. He was never taken to the hospital. The Spencers couldn’t afford it.

Spencer’s grandfather, Clarence, lost his job, then Merle, and then his vital organs to tuberculosis at age 34. He drank himself to death, said Spencer, whose father, William, was only 8 years old at the time.

William’s family was poor before his dad died. “They were hyper-poor after that,” Spencer said. So poor that as a 10-year-old, William worked at a corn canning factory just to put food in his belly.

William, however, excelled in school and athletics. The military also helped Spencer’s father.

After William Spencer returned from fighting in the Korean War, he came back and finished his degree, funded by an athletics scholarship. He later used his G.I. Bill benefits to get two master’s degrees.

“He wanted to make sure his family wasn’t dirt-poor and left destitute if he dropped dead,” Spencer said.

Spencer’s father retired from the military after a 30-year career. After he got out, he decided to get a master’s in education. He had a calling for teaching kids on the autism spectrum, Spencer said. Unfortunately, he only got to do that for a few years before cancer took his life at age 67.

A photograph in David Spencer's office of his son playing in front of his father's grave.
A photograph in David Spencer’s office shows his son playing in front of his grandfather’s grave. Credit: Bonnie Arbittier / San Antonio Report

Consumed by the family’s spiral of poverty, Clarence Spencer would have been stunned to see that his grandson would become an engineer and multimillionaire.

‘I didn’t know boo about business’

Spencer had a 10-year plan, but seven years in, that plan was derailed. Spencer was an engineering manager at Kelly Air Force Base when the government announced its closure in 1995. The base closed down in 2001.

His career working as a civilian software engineer in the military had followed the trajectory he envisioned for himself at the time, but Spencer was unexpectedly diverted before he could learn what he needed to know about his next path – entrepreneurship.

“I was an engineer,” he said. “I didn’t know boo about business. I knew I wanted to do it, so I had to go learn.”

Paying $10 a class and voraciously reading business books, Spencer got a crash course in entrepreneurship while taking night classes at the University of Texas at San Antonio and then founded his first company, OnBoard Software, in 1996 while he was still in his 20s. In 2005, at age 36, he sold the company for $34 million.

After acquiring new wealth, he became a full-time investor, founding Texas Intrepid Ventures, which focuses on providing capital for new medical devices needed in the wars in Iraq and Afghanistan.

In 2011, he partnered with Christopher Banas, an experienced medical device entrepreneur who helped fill in the gaps for Spencer on how to work with the military and take a research product into the commercial market. Spencer was relatively green in the medical device space when he launched his failed venture, Speer, in 2009. The relationship was a shot at redemption for Spencer, who, after being forced to shutter Speer, said the experience left him “in a hole.”

Together, Banas and Spencer helped take the REBOA from a research product to a device that has been used an estimated 4,000 times in the battlefield and in civilian medical centers, said Col. Dr. Todd Rasmussen, who co-invented the device.

“He has an uncommon amount of vision and he has some intensity that is required to really get what can be a fragile research project into a legitimate position in the marketplace,” Rasmussen said of Spencer.

Following the opportunity

Spencer, a gregarious and loquacious personality, was – perhaps uncharacteristically – not fond of the spotlight in an interview with the Rivard Report last week. He knew it was a profile, and he was the subject.

“I’ll tell you my story all day long,” he said, tongue firmly in cheek. “I love the melodious sound of my voice.”

He pitched an alternative story thesis: “The more important underlying piece here for your readers to understand is in San Antonio there’s some untapped opportunity,” he said, highlighting in particular the opportunity in the local cybersecurity and military medical research areas.

“If I’m good at one thing,” said Spencer. “It’s seeing ahead what those opportunities are, and my career in San Antonio has kind of followed that.”

And his latest venture has produced gratification at a more profound level than he experienced making software. That much is evident when he, gesturing toward a color-coded map dotted with pushpins in the places the REBOA has saved lives, tells the stories behind the testimonies for the REBOA. Rasmussen, who has known Spencer for about six years, said he hears it in his voice when Spencer calls, excited about the immediate impact the device is having.

David Spencer is reflected in the glass of a memento of the ER-REBOA's first life saved.
David Spencer’s reflection shows in the glass of plaque commemorating the first life saved by the ER-REBOA. Credit: Bonnie Arbittier / San Antonio Report

That’s refreshing for Rasmussen, a surgeon whose professional interactions largely take place with other surgeons. Because surgeons are inured to hearing about patient outcomes, the response to such anecdotes can sometimes be detached, he said. But Spencer oozes with enthusiasm.

“He’ll say, ‘This is so cool!’” Rasmussen said. “I’m excited with him certainly, but surgeons we almost see this daily. I think he gets a deeper sense of meaning from this project because of that.”

JJ Velasquez

JJ Velasquez

JJ Velasquez was a columnist, former editor and reporter at the San Antonio Report.