Our Summary

The research paper discusses whether astronauts should have their spleen removed before going on long spaceflights. The spleen can be at risk from radiation and injury during space travel. However, removing it also carries serious risks.

The researchers looked at data from the last 50 years on the risks of spleen removal and the risks of radiation damage to the spleen during long spaceflights. They reviewed 41 articles in total.

The immediate risks of spleen removal include a 3-5% chance of dying during the operation due to bleeding, a 6% chance of dying from complications after the operation, a 10% chance of a blood clot, and a 5-37% chance of a blood clot in the portal vein. Long-term risks include a 0.5% chance of a severe infection 5 years after the operation, up to a 60% chance of dying from a type of infection called pneumococcal, and an increased chance of developing cancer.

When it comes to radiation exposure, one’s risk of blood cancer significantly increases when exposed to 40 Gy of radiation, which is much higher than the 0.6 Gy of radiation one would experience on a round trip to Mars that lasts 12 months. Lower doses of radiation increase the risk of a poorly functioning spleen more than they do blood cancer.

The researchers concluded that the risks of removing the spleen outweigh the benefits when it comes to protecting against blood cancer. However, long spaceflights could potentially lead to a poorly functioning spleen. To help protect against this, they suggest giving astronauts vaccines against certain types of bacteria before they embark on long spaceflights.

FAQs

  1. What are the acute and delayed risks associated with splenectomy?
  2. What is the risk of hematologic malignancy from radiation during long duration spaceflight?
  3. Should astronauts be given vaccines against encapsulated organisms to mitigate the risk of hyposplenism?

Doctor’s Tip

A helpful tip a doctor might give a patient about splenectomy is to be aware of the risks associated with the procedure, including the potential for complications such as thromboembolic events, portal vein thrombosis, and overwhelming postsplenectomy infection. It is important for patients to discuss these risks with their healthcare provider and to follow any recommendations for preventive measures, such as receiving vaccinations against encapsulated organisms to help protect against infections in the absence of a spleen.

Suitable For

Patients who are typically recommended for splenectomy include those with conditions such as hereditary spherocytosis, thalassemia, autoimmune hemolytic anemia, idiopathic thrombocytopenic purpura (ITP), and certain types of lymphoma. Additionally, patients with trauma to the spleen or certain types of splenic tumors may also be recommended for splenectomy.

Timeline

Before splenectomy:

  1. Patient is diagnosed with a condition that may require splenectomy, such as a ruptured spleen, idiopathic thrombocytopenic purpura, or hereditary spherocytosis.
  2. Patient undergoes preoperative evaluations, including blood tests, imaging studies, and consultations with specialists.
  3. Patient receives education about the procedure and potential risks and benefits.

After splenectomy:

  1. Patient undergoes the surgical procedure to remove the spleen, which typically lasts 1-4 hours.
  2. Patient is monitored closely in the recovery room for any complications, such as bleeding or infection.
  3. Patient may experience pain at the incision site and may need pain medication.
  4. Patient is discharged from the hospital after a few days and instructed on postoperative care, including wound care and activity restrictions.
  5. Patient is at increased risk for infections, particularly from encapsulated organisms, due to the loss of spleen function.
  6. Patient may need to receive vaccinations against encapsulated organisms to reduce the risk of infection.
  7. Patient is followed up regularly by healthcare providers to monitor for any long-term complications, such as overwhelming postsplenectomy infection or development of malignancy.

What to Ask Your Doctor

  1. What are the potential risks and benefits of undergoing a splenectomy prior to long duration spaceflight?
  2. What is the mortality rate associated with splenectomy, both intraoperatively and from postoperative complications?
  3. What are the risks of developing complications such as thromboembolic events or portal vein thrombosis after splenectomy?
  4. How does splenectomy affect the risk of overwhelming postsplenectomy infection (OPSI) and mortality rates from infections such as pneumococcal infections?
  5. What is the risk of developing malignancies after undergoing a splenectomy?
  6. How does the risk of hyposplenism from long duration spaceflight compare to the risks associated with splenectomy?
  7. What measures can be taken to mitigate the risk of hyposplenism during long duration spaceflight, such as prophylactic vaccines against encapsulated organisms?
  8. Are there alternative options to splenectomy for protecting against hematologic malignancies during spaceflight?
  9. How does the radiation exposure during spaceflight compare to the risk of developing hematologic malignancies?

Reference

Authors: Siu M, Levin D, Christiansen R, Kelly E, Alouidor R, Kamine TH. Journal: Aerosp Med Hum Perform. 2022 Dec 1;93(12):877-881. doi: 10.3357/AMHP.6079.2022. PMID: 36757247