What hematologic disease has the highest postoperative morbidity after splenectomy?

Postoperative Morbidity After Splenectomy for Hematologic Diseases

Myeloid dysplasia has the highest postoperative morbidity after splenectomy among the listed hematologic diseases. 1

Evidence-Based Comparison of Morbidity Rates

Myeloid dysplasia/myelofibrosis stands out as having significantly higher postoperative complications compared to other hematologic conditions:

• Myeloid dysplasia/myelofibrosis: 50% complication rate with 5-10% perioperative mortality 1
• Idiopathic thrombocytopenic purpura (ITP): Approximately 10% surgical complication rate, even with less-invasive laparoscopic methods 2
• Hereditary spherocytosis: Less than 20% complication rate 3
• Sickle cell anemia: Not specifically quantified in the evidence but lower than myeloid dysplasia
• Thalassemia: Not specifically quantified in the evidence but lower than myeloid dysplasia

Why Myeloid Dysplasia Has Highest Morbidity

Several factors contribute to the increased risk in myeloid dysplasia/myelofibrosis:

1. Massive splenomegaly: Patients with myelofibrosis often have extremely enlarged spleens

   • Splenic weight >1,500g significantly increases operative blood loss (median 300ml) 4
   • Increased blood loss is directly correlated with postoperative complications (p=0.02) 4

2. Thrombocytopenia and thrombocytosis complications:

   • Pre-operative thrombocytopenia is associated with decreased post-splenectomy survival 5
   • Post-operative thrombocytosis occurs in 22% of myelofibrosis patients 5
   • Thrombocytosis increases risk of perioperative thrombosis 5

3. Higher risk of blast transformation:

   • 16.3% rate of blast transformation in myelofibrosis patients after splenectomy 5

4. Hepatomegaly: Substantial liver enlargement occurs in 16.1% of patients after splenectomy for myelofibrosis 5

Comparison with Other Conditions

• ITP: Despite being commonly treated with splenectomy, ITP has a much lower complication rate (10%) 2

  • Response rates are high (85% initial response) 2
  • Long-term complications are primarily related to asplenic state rather than immediate surgical complications

• Hereditary spherocytosis: Has one of the lowest complication rates among hematologic diseases requiring splenectomy 3

  • Typically performed in younger, otherwise healthy patients
  • Less likely to have massive splenomegaly

• Sickle cell anemia and thalassemia: While these conditions can have complications related to their underlying pathophysiology, their postoperative morbidity rates are not as high as myeloid dysplasia 6

Clinical Implications

The American College of Surgeons recommends careful patient selection for splenectomy in patients with myeloid dysplasia/myelofibrosis due to the high morbidity rates 1. Specific considerations include:

• Monitoring for extreme thrombocytosis post-operatively
• Maintaining platelet count below 400×10^9/L to prevent thrombotic complications
• Anticipating potential massive blood loss during surgery
• Preparing for higher risk of infectious complications

In conclusion, among the hematologic diseases listed, myeloid dysplasia (answer choice c) clearly demonstrates the highest postoperative morbidity after splenectomy based on the most recent and highest quality evidence.