1. Improper operation. The doctor must follow the correct operation steps, otherwise the rescue may fail.
2. Limit the number of rescues. The number of people that space surgeons can treat is limited.
3. Handling of emergencies. In space operations, doctors need to face complex emergencies and try their best to rescue and treat astronauts. Due to the complexity of space operations and the limitation of resources, medical assistance will be limited to a certain extent, and doctors must make a balance and decision to make maximum use of limited resources to rescue astronauts.
This is just a possible reason based on some information. It is best to ask the space surgeon for accurate information.