Evaluation of a comprehensive transcranial doppler screening program for children with sickle cell anemia

Abstract

Background: Although transcranial Doppler ultrasonography (TCD) screening is effective in identifying children with sickle cell anemia (SCA) who are at high risk of stroke, not all children are screened. In 2003, we instituted a comprehensive TCD screening program designed to screen all at-risk children treated at our sickle cell center.

Procedure: We evaluated the efficacy of our program by comparing the number of patients screened per year and incidence of first stroke across three periods defined by TCD usage: (1) pre-dating TCD screening, (2) sporadic TCD screening, and (3) comprehensive TCD screening.

Results: During Period 2, an average of 52 patients/year were screened. In Period 3, an average of 95 patients/year were screened representing 99% of the at-risk population. Eighteen strokes occurred in Period 1, 22 in Period 2 and three in Period 3. The first stroke incidence was significantly lower in Period 3 compared to Periods 1 and 2 (P = 0.047). Furthermore, of the 25 patients in Periods 2 and 3 who had stroke, only six had received TCD screening (four in Period 2, two in Period 3). These six either declined prophylactic transfusion therapy (n = 2), had co-existing stroke risk factors (n = 2), or did not return for appropriate TCD follow-up (n = 2). Therefore, strokes that occurred were not the result of a failure of TCD screening per se.

Conclusions: It is possible to perform TCD screening of most children with SCA. TCD screening is effective in reducing first stroke incidence in these children.