In fact, this has happened before. A Russian cosmonaut developed appendicitis while on a mission in space, and as a result had to quickly return to Earth. While this kind of surgery is relatively common on Earth, it's brand new territory in space, and no one knows the consequences of having it done in space.
On another occasion, two months after a six-month mission to the International Space Station, an astronaut got a blood clot. It was part of a study to assess the effects of microgravity on the jugular vein. With the help of experts on the ground, the astronaut had an ultrasound done in space and was instructed to inject drugs already on the ISS. Over time, the blood clots shrank, and when the astronauts later returned to Earth, the clots had disappeared within 24 hours.
But what if? What if the astronaut gets another disease? What if there's an accident and surgery is needed?
The first human missions back to the moon and Mars are about to be realized. Much of the discussion has been about the technical challenges of these missions. But the medical challenges are real, too. All this focus on space surgery is in response to a new interest in space exploration.
Space Surgery Question 1: Distance
The first thing to consider is the distance involved. A medical emergency on the ISS means stabilizing the patient with real-time assistance from ground specialists. Ultimately, the patient can return to Earth.
What if it was on the Moon? Returning to Earth would be a problem. Mars would be a problem; the minimum distance between Mars and Earth is about 54.6 million kilometers, and the maximum distance is about 401 million kilometers. The average distance is about 225 million kilometers. When a spacecraft is launched in the right-hand window, it takes about six months to travel between Mars and Earth. In a medical emergency, assistance from specialists on Earth could suffer communication delays of up to 20 minutes. If necessary, the return could take much longer than six months.
Space Surgery Problem #2: Gravity
Distance isn't the only problem, though. The other primary issue may be microgravity. Not only the chronic effects of months or years of microgravity, but also the effects of operating on the human body with little or no gravity.
The body's response to microgravity causes redistribution of blood. Blood is concentrated in the head, and the rest of the body must compensate for this. There is less blood in the heart and vascular system. This change is accompanied by a number of other changes, and the result is a reduction in plasma volume and blood volume.
As a result, the body lowers its heart rate and blood pressure, and the body becomes more susceptible to infection. Therefore it can be dangerous once an emergency surgery is done.
So a successful space medical emergency program must take into account the possibility of serious injuries requiring surgery. Studies have shown that a seven-person astronaut would have an emergency requiring surgery every 2.4 years during a Mars mission. The researchers also found the most likely scenarios: appendicitis, injury, gallbladder inflammation and cancer. These problems can arise suddenly, even when astronaut candidates undergo rigorous health checks.
Regarding distance, robot-assisted surgery is a potential localized solution for space surgery. Robotic surgeons are used for some heart surgeries, some thoracic surgeries, some gastrointestinal surgeries, and others. But these systems are not artificially intelligent surgeons. They are controlled remotely by surgeons, which is not possible when it takes 20 minutes for a signal to reach Mars.
Another problem with space surgery and medicine is supply. Human space is always limited to spacecraft, so we have to make careful decisions about how much medical equipment can be carried? The ISS has an on-board pharmacy with blood thinners and syringes. But it can't take everything for any emergencies.
What about 3D printers? If 3D printers can help bridge the gap between what's needed and what's on hand, maybe everything doesn't need to be carried around.3D printers could potentially be used to make at least some types of medical supplies. There have been several studies looking at this, one of which was conducted during a 4-month simulated Mars Earth mission. In this case, crew members with no surgical experience successfully performed 16 sets of timed simulated preparation, draping, cutting, and suturing tasks to assess the relative speed of using four ABS thermoplastic instruments printed on Earth compared to conventional instruments."
While these findings are limited, they show at least some potential for on-demand 3D printing of surgical devices. Some of the devices could even potentially be 3D printed on Mars from in situ sources, although that's a long way off.
Every crew member on a Mars mission is mission-critical. Losing a crew member, either by death or incapacitation, could mean that the mission would not be able to achieve its goals. An incapacitated crew member could also put other crew members at greater risk.