Advantages of isovolemic hemodilution-red cell exchange therapy to prevent recurrent stroke in sickle cell anemia patients.

Chronic simple hypertransfusion (every 3 to 4 weeks) effectively prevents secondary stroke in children with sickle cell anemia but leads to iron overload despite chelation therapy. Conventional red blood cell exchange (C-RBCx) has advantages over simple transfusion: no net iron gain and less frequent hospital visits. However, C-RBCx requires more red blood cell units, an apheresis instrument and skilled personnel; it is also more expensive. We developed a modified procedure where isovolemic hemodilution precedes RBCx (IHD-RBCx) to decrease RBC units required and to increase the interval between procedures. Twenty patients underwent IHD-RBCx over a period of 7 years. IHD-RBCx required 11% fewer RBC units and increased inter-procedure interval from 37 to 53 days compared to C-RBCx. The median number of annual procedures decreased from 9.8 to 7.0 per patient, resulting in estimated savings of more than $4.5 million over 10 years for 20 patients while providing improved care. Five patients have discontinued chelation therapy; three while on C-RBCx and two while on IHD-RBCx. No adverse events occurred related to the isovolemic hemodilution phase and no patients had recurrent stroke. IHD-RBCx is a safe, efficient, and cost effective therapy for secondary prevention of stroke in patients with sickle cell anemia.