Secondary iron overload, caused by chronic transfusions, is common among patients who have chronic hemolytic disorders, especially sickle cell disease and thalassemias. Accurate assessment of the hypertransfused patient’s body iron burden is important in deciding when and whether to start chelation therapy in order to prevent iron -related toxicities such as heart failure and endocrine abnormalities. The gold standard to measure iron content is through a liver biopsy. Though shown to be safe, many physicians are still reluctant to use this invasive approach in children to evaluate liver iron content.
Study Design: A retrospective chart review of chronically transfused patients at Texas Children’s Hospital (1998–2003) was performed to assess possible biopsy complications, including pain, hemorrhage, bilious peritonitis, puncturing of other organs, and bacterial infections, in patients with hemolytic disorders. The study was approved by the Institutional Review Board.
Results: There were 65 biopsies, 43 patients had one biopsy and 11 patients had two biopsies. 56 % were male, 44 % were female; 52% (28/54) were African American, 15 % (8/54) were Oriental/Asian, and 22 % (12/54) were Hispanic. 30 patients (56%) had sickle cell disease, 16 (30%) thalassemias, 5 (14%) other forms of anemia, 1 patient had leukemia, and 1 had lymphoma with the sickle cell trait. Eight of these patients (15%) are not on or have never been on chelation therapy, 11 (20%) used to be on chelation therapy, 35 (65%) are currently on chelation therapy. The average age when the first biopsy was performed was 11 years (range 2 to 18.9 years); and the average age at the time of the second biopsy was 12.7 years (range, 5.8 to 21.1 years). The reasons for their biopsies included possible iron overload due to hypertransfusions, pre-bone marrow transplant evaluation, and elevated liver enzymes. The average serum ferritin level before biopsy was 2681.8 ng/mL ranging from 348 to 35,332 ng/mL, and the average liver iron content (LIC) determined through biopsy was 12,278 ug/g dry wt. Ultrasound guidance was used for all 65 biopsies; 46 (71%) biopsies were done percutaneously, 8 (12%) laparoscopically, and 6 (10%) through an open procedure. There were no complications during the biopsy. There were no major and only 5 minor complications after the biopsy: 3 patients (5%) had transient abdominal pain at the biopsy site which subsided over a couple of days, and 2 (3%) had a fever with other (non-biopsy-related) complications requiring an increased hospital stay.
Conclusions: Liver biopsies in the pediatric population are safe and feasible and they should be considered for the accurate assessment of iron content in chronically transfused patients. Certain factors contributing to the success of the biopsies include having an experienced physician, using ultrasound guidance, and fully informing the patient or patient’s parents about the biopsy before the procedure.