Risk of Recurrent Acute Splenic Sequestration Crisis
Acute splenic sequestration crisis recurs frequently after the initial episode, with approximately 50-67% of pediatric patients with sickle cell disease experiencing more than one episode, making it a highly recurrent complication that warrants definitive intervention. 1
Recurrence Rates and Risk Factors
The recurrence rate is substantial: In a cohort of 190 pediatric patients with SS or Sβ⁰ thalassemia who experienced acute splenic sequestration crisis, 67% had more than one episode, with a total of 437 episodes occurring at a rate of 0.06 per patient-year. 1
Age at first episode is the primary predictor of recurrence: Patients whose first episode occurs before 1 year of age have a significantly higher risk of recurrence compared to those whose first episode occurs after 2 years of age (hazard ratio 0.60 for later onset; 95% CI 0.41-0.88; P=0.025). 1
Transfusion therapy does not prevent recurrence: The risk of recurrent splenic sequestration was similar for patients who received transfusion therapy compared to those who were simply observed, indicating that short-term transfusion programs to prevent recurrence are of limited benefit. 2
Clinical Implications for Management
Splenectomy is the definitive preventive measure: The American Academy of Pediatrics recommends surgical splenectomy after recovery from life-threatening or recurrent episodes to prevent future occurrences. 3
Timing of splenectomy varies by age: Based on clinical experience, splenectomy is recommended after the first episode in children 5 years of age and older, while children under 3 years may be managed with a year or more of long-term transfusion therapy before considering surgery. 4
Partial splenectomy is an alternative: In one series of 6 patients who underwent partial splenectomy, none experienced splenic sequestration post-procedure (down from 2.1 ± 1.0 sequestrations per year; P=0.003), with no increase in infection-related hospital admissions during follow-up. 5
Common Pitfalls
Delayed recognition leads to mortality: The mortality rate from acute splenic sequestration crisis is approximately 0.53%, with death resulting from rapid progression to hypovolemic shock when recognition is delayed. 1, 3
Overtransfusion during acute management: Care must be taken to avoid acute overtransfusion to hemoglobin greater than 10 g/dL, as sequestered red cells may be acutely released from the spleen as the event resolves. 3
False security with transfusion programs: Sequestration crisis may occur despite reduction in hemoglobin S concentration to less than 30% of total hemoglobin mass, and transfusion therapy does not reliably prevent recurrence. 2