Doctor’s long-distance call. Stephan Moll and a team of NASA doctors prescribed blood clot treatment.
Credit: UNC School of Medicine

An unidentified astronaut aboard the International Space Station had a deep vein thrombosis (DVT) – or blood clot – in the jugular vein of their neck.

The astronaut’s identity is being kept anonymous for privacy reasons, so identifying information such as when this event happened is being omitted from the case study. The astronaut was two months into a six-month mission on the ISS when the DVT was discovered.

This was the first time a blood clot had been found in an astronaut in space, so there was no established method of treatment for DVT in zero gravity.

Blood clot expert

One of the experts brought in by NASA to treat the situation was blood clot expert Stephan Moll, MD, professor of medicine at the University of North Carolina School of Medicine, Chapel Hill. Moll was the only non-NASA physician NASA consulted.

Moll and a team of NASA doctors decided blood thinners would be the best course of treatment for the astronaut. They were limited in their pharmaceutical options, however.

The ISS keeps only a small supply of various medicines on board, and there was a limited amount of the blood thinner Enoxaparin (Lovenox®) available. Moll advised NASA on what dosage of Enoxaparin would effectively treat the DVT while also lasting long enough, until NASA could get a new shipment of drugs – which Moll helped select – to the ISS.

Treatment process

The course of treatment with Enoxaparin – a drug delivered by an injection into the skin – lasted for around 40 days. On day 43 of the astronaut’s treatment, a supply of Apixaban (Eliquis®) – a pill taken orally– was delivered to the ISS by a supply spacecraft.

Throughout the treatment process, which lasted more than 90 days, the astronaut performed ultrasounds on their own neck with guidance from a radiology team on Earth in order to monitor the blood clot. Moll was also able to speak to the astronaut during this period through email and phone calls.

Credit: NASA

The astronaut landed safely on Earth and the blood clot required no further treatment.

More research needed

Somewhat ironically, the DVT was discovered when the astronaut was taking ultrasounds of their neck for a research study on how body fluid is redistributed in zero gravity. If it wasn’t for the study, there’s no telling what the outcome could have been. Moll says there’s a need for more research of how blood and blood clots behave in space.

“Is this something that is more common in space?” posed Moll in a UNC Health Care and UNC School of Medicine press statement.

Credit: NASA

“How do you minimize risk for DVT? Should there be more medications for it kept on the ISS? All of these questions need answering, especially with the plan that astronauts will embark on longer missions to the Moon and Mars,” Moll points out.

Credit: NASA





Moll co-wrote a case study on the successful treatment that has been published in the New England Journal of Medicine. That case study – “Venous Thrombosis during Spaceflight” — can be found here:

Video Note: You could call it the ultimate telemedicine. A UNC expert enlisted by NASA to help treat an astronaut during a mission on the International Space Station. Hear about the experience from Dr. Stephan Moll in his own words.

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One Response to “Astronaut Suffers Blood Clot in Space: Telemedicine Solution”

  • Ùte says:

    Why does everyone claim that the astronaut’s identity hasn’t been disclosed if everyone can see who the authors of the paper are? This doesn’t make any sense.

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