Results
Twenty-one (11 HbSS, 9 HbSβ0 Thal, and 1 HbSD) out of the 43 patients in the original study were successfully recalled and studied. Of the other 22 patients who could not be studied, 11 were away in college, 6 had changed their phone numbers, and 5 did not give consent. The mean age of the 21 patients at the time of the initial TCDI was 6.5±1.2 and at the time of the follow-up scan the mean was 16.0 ± 1.6 years. The mean follow-up was 10.1 ± 3.1 years (range, 7 - 10 years). There was a predominance of girls (62%) over males (38%). All the patients were on hydroxyurea (HU) between 2012 and 2022.
The patients presented significantly lower mean total Hb, hematocrit, and bilirubin but significantly higher HbF, platelets, and ANC counts than in the initial study. The mean LDH, WBC, and reticulocyte count showed no significant differences. Subjects’ characteristics are summarized in Table1.
There were significant differences (p<0.05) between old and follow-up data for all vascular parameters in all vessels. In general, follow-up SCD patients showed lower values than the old data although the values were within the normal range in all the cerebral arteries. All TAMMV values were less than 170 cm/s, and no PSV value exceeded 200 cm/s in any vessel. Normal values of PI (0.5-1.2) and RI (0.5-0.7) were observed in both old and follow-up studies. The mean ± SD of TAMMV for old and follow-up data for t-ICA, MCA, ACA, and PCA were 77.3±20.9, 71.6±9.9; 94.3±25.8, 82±18.2; 76.6±25.6, 70.6±10.7; and 59.1±15.8, 63.9±8.5, respectively. There was positive statistically significant difference for PSV and significant negative differences for RI and PI (P<0.05). There was no statistically significant difference for EDV and TAMMV (P>0.05). There were no statistically significant inter-hemispheric differences (p<0.05) in both groups for all parameters. Results are summarized in Table 2.