Abnormal Lower Extremity Hemodynamics at Doppler US in Children with Sickle Cell Anemia

Abstract

Background Children with sickle cell anemia (SCA) are predisposed to developing leg ulcers in early adolescence; however, the underlying physiologic mechanisms are not well understood, which hinders the development of prophylactic antiulcer interventions. Purpose To determine if occlusive arterial disease or abnormal hemodynamics exist in the lower limb peripheral arteries of children with SCA. Materials and Methods This was a prospective cross-sectional study conducted between July 2020 and May 2021. Two groups of participants were enrolled: children with SCA and healthy controls. Each child had their anthropometric measurements taken, followed by B-mode, color Doppler, and spectral Doppler US evaluation of the distal anterior and posterior tibial arteries. Ankle-brachial index evaluation was also performed. Hemodynamic values were compared between children with SCA and healthy controls, with statistical significance set at the P < .05 level. Results Forty-five children with SCA (mean age, 9.5 years ± 3.7 [SD]; 26 boys) and 45 healthy controls (mean age, 9.3 years ± 3.8; 25 boys) were evaluated. Children with SCA had higher peak systolic velocities, end-diastolic velocities, and blood volume flow in their distal anterior and posterior tibial arteries compared with the healthy participants (P < .001 across all 12 measurements). Children with SCA also had lower resistive index and pulsatility index values compared with healthy controls in at least one of the anterior and posterior tibial arteries bilaterally. Monophasic spectral patterns were exclusively observed in participants with SCA. The ankle-brachial index values for the participants with SCA (mean, 1.09 ± 0.08) and healthy participants (mean, 1.06 ± 0.02) were within normal range. Conclusion Abnormal peripheral hemodynamic characteristics were found in the lower limbs of children with sickle cell anemia. No evidence of occlusive peripheral artery disease was present. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Paltiel in this issue.