Updating the role of transcranial Doppler in prediction and prevention of stroke in correlation to the regularity of blood transfusion in Egyptian children with sickle cell anemia

Abstract

Background: The Sickle cell disease (SCD) is a hemoglobinopathy that is recessively inherited commonly among people of Equatorial African, Saudi Arabian, and Mediterranean ancestry. It is characterized by chronic hemolytic anemia and intermittent vaso-occlusive events. The stroke is a common complication of SCD, which occurs in approximately 7% of children with SCD. The Transcranial Doppler ultrasonography is the only noninvasive examination that provides a reliable evaluation of intracranial blood flow patterns in real time with no need for sedation of the patient. The TCD can identify children with the highest risk of the first-ever stroke and those in need of prophylactic blood transfusion, as the blood transfusion is not in the protocol of management of SCD till now but just after complication occurrence. So, it is important to know if the chronicity and the regularity of the transfusion are useful or not. Results: Sixty-nine patients diagnosed with sickle cell disease, recruited from the pediatric hematology outpatient clinic, over a period of 7 months, with age 2–13 years, examined by transcranial Doppler ultrasound. 44.9% of them were on regular blood transfusion, 39.1% occasionally transfused and 15.9% never transfused. Transcranial Doppler parameters of the cerebral arteries, namely TAMAX, PSV, were correlated with the frequency of transfusion and with (STOP) classification of the stroke risk. The Doppler parameters were also correlated with the different clinical parameters. The right MCA PSV and left DICA PSV were significantly higher among patients who were never transfused before. The Right DICA TAMAX was significantly higher among patients on regular transfusion, and the left DICA TAmax was significantly higher among patients who were never transfused before. Patients with high risk of stroke were diagnosed at a significantly older age. Regarding the laboratory parameters, platelets were significantly lower and total and direct bilirubin was significantly higher among the high stroke risk patients. Conclusions: The regularity of the blood transfusion is extremely important in the stroke prevention. The most important velocities that may act as indicators for the risk are TAMAX of both DICAs and PSV of RT MCA & LT DICA.