Post-splenectomy state

Which of the following are potential complications of splenectomy (more than one answer may apply):

In this section we will discuss 2 important complications of splenectomy:

• Infection
• Thrombosis

Infectious risk

Asplenia and hyposplenism are major risk factors for overwhelming sepsis (more than 50-times higher than in the general population; lifetime risk 1% to 2%), especially with encapsulated organisms such as:

• S. pneumoniae (50–90% of cases)
• N. meningitidis
• H. influenzae type b

(Additionally, splenectomized patients are at increased risk of severe zoonotic diseases caused by Babesia, Bordetella, and Capnocytophaga species, occurring after tick, cat, and dog bites, respectively).

Fever in a patient with splenectomy:

• Is a medical emergency.
• Requires prompt treatment with empirical antibiotics.

Asplenic sepsis has a mortality rate of 50–70%.

The risk of sepsis is highest in the first 2 years following surgery, but remains elevated lifelong.

Given the seriousness of this complication, what steps would you like to take in our patient (more than one answer may apply):

Vaccinations for splenectomized patients

All vaccines should be given ≥ 2 weeks prior to splenectomy if possible or 2 weeks post splenectomy.

Adults who are undergoing splenectomy or who have functional or anatomic asplenia or hyposplenism should receive vaccinations against S. pneumoniae (pneumococcus), H. influenzae type b, and N. meningitidis (meningococcus):

• Pneumococcal vaccination
  • Two types of pneumococcal vaccination may be used:
    • PCV20 (Prevnar 20; preferred over other PCVs because it provide protection against 20 serotypes and does not require supplementation with a polysaccharide vaccine)
    • PCV13 (Prevnar 13) + PPSV23 (Pneumovax)
  • For adults with impaired splenic function who have not previously received a pneumococcal vaccine or whose vaccination history is unknown, give one dose of PCV20. If PCV20 is not available, PCV15 can be used. If PCV15 is used, PPSV23 should be given ≥8 weeks after the PCV15 dose
  • For those who have previously received a pneumococcal vaccine, the approach to vaccination varies based on the type of vaccine given:
    • Adults who have already received both a PCV and PPSV23 vaccine require no further vaccination.
    • Adults who have only received the PCV13 should receive the PPSV23 vaccine ≥8 weeks after receipt of PCV13.
    • Adults who have only received the PPSV23 vaccine should receive PCV15 or PCV20 at least a year after PPSV23.
• H. influenzae type b vaccination (Hib)
  • A single dose of Hib vaccine is recommended prior to splenectomy or for patients with asplenia or hyposplenism.
  • If the patient doesn’t know whether they have been vaccinated in past, give a single dose.
  • Revaccination is not needed for Hib (no booster).
• Meningococcal vaccination 
  • Two types of meningococcal vaccinations recommended:
    • Quadrivalent meningococcal conjugate vaccine that protects against meningococcal serotypes A, C, W, and Y  (MenACWY; Menactra, Menveo, MenQuadfi)
    • Univalent serogroup B vaccine (MenB-4C [Bexsero] or MenB-FHbp [Trumenba])
  • Both vaccines are given as a primary series:
    • Give two doses of a MenACWY vaccine ≥8 weeks apart, booster every five years.
    • Meningococcus serogroup B (MenB), either with Bexsero (two doses spaced at least one month apart) or Trumenba (three doses at 0, 1 to 2, and 6 months); booster 1 year after completion of primary series and every 2 to 3 years thereafter.

All splenectomized patients should receive influenza vaccine yearly.

Thrombotic risk

Splenectomy has also been shown to be a risk factor for thromboembolic events such as portal vein thrombosis, deep vein thrombosis, and pulmonary embolism.

The mechanism of thrombophilia is not well understood but may be associated with the role of the spleen in clearing microparticles from the circulation as well as increased platelet counts following splenectomy.

There is currently no guidance regarding thromboprophylaxis in these patients. Grace et al recommend the following:

• Prophylactic anticoagulation can be considered, once safe from a bleeding perspective, immediately post-splenectomy, in those with other thrombotic risk factors.
• Low dose aspirin could be considered until the platelet count is <500 x 10⁹/L in adults with advanced age, a history of thrombosis, hypercholesterolemia and cigarette smoking.