Pediatric Sinusoidal Obstruction Syndrome

• Etiology:
  — Seen in bone marrow transplant patients
  — Induced by total body irradiation and chemotherapy
  — Is injury to sinusoidal endothelial cells and hepatocytes with fibrinous obliteration of sinusoids and central veins
• Imaging: Is primarily a clinical diagnosis supported by imaging and to make the diagnosis you need 2 or more of:
  — Unexplained consumptive or transfusion-refractory thrombocytopenia
  — Unexplained weight gain
  — Hepatomegaly above baseline
  — Ascites above baseline
  — Rising bilirubin above baseline
• Imaging US:
  — Decreased or slow or reversed portal vein flow is associated with sinusoidal obstruction syndrome – nothing else predicts sinusoidal obstruction syndrome
  — Narrowed or compressed hepatic veins with monophasic flow with decreased pulsatility and elevated hepatic arterial resistive index
  — Commonly see hepatomegaly, gallbladder wall thickening often greater than 6 millimeters, ascites, portal vein may be distended greater than 8 millimeters
• DDX: Graft versus host disease, hepatitis, drug-induced cholestasis
• Complications:
• Treatment:
• Clinical:
  — Serious complication of bone marrow transplant
  — 80% occur within 21 days of transplant
  — More common in children than in adults

Radiology Cases of Sinusoidal Obstruction Syndrome