Contrast-enhanced CT evaluation of intra-abdominal vessels in sickle cell anemia

Abstract

Abstract Background Sickle cell anemia (SCA) is a hereditary hematological disorder that affects millions of people worldwide. Abdominal crisis can result in significant morbidity and mortality if bowel infarction is present. Vaso-occlusive crisis is the most common pathological process accounting for morbidities. However, another mechanism was recently proposed for the arteriovascular changes associated with SCA. The terminology “sickle cell vasculopathy” was raised. Unlike the intra-cranial arterial vascular abnormalities associated with SCA (frequently reported findings of Moyamoya syndrome), there is scarce radiology literature describing the intra-abdominal vascular changes during or outside a crisis in SCA. Contrast-enhanced CT is a frequently used modality to assess abdominal vasculature and end-organ damage in acute abdominal crisis. Knowledge of the morphology of intra-abdominal vessels, especially the arteries may explain the underlying mechanism of abdominal crisis and potentially alter the management. The study aims to evaluate the structure of the intra-abdominal vasculature in SCA patients using contrast-enhanced computed tomography (CT) images. Methods This retrospective study reviewed the medical records of SCA patients who underwent contrast-enhanced CT of the abdomen and pelvis between 2003 and 2020 irrespective of abdominal crisis status. The CT studies were reviewed for the presence of vascular abnormalities, ischemic bowel changes, or other end-organ ischemic changes. Results Out of 509 patients, only 78 met the inclusion criteria. Two patients showed diffuse small caliber of the intra-abdominal arteries in the setting of abdominal crisis with end-organ ischemia but no bowel changes. None of the CT studies showed arteriovascular manifestations like advanced intra-cranial vasculopathy in SCA (Moyamoya syndrome-like changes) and none had vasculitis-like abnormalities. None of the patients had bowel ischemia, but six patients had renal and splenic infarcts in the absence of vascular abnormalities. One patient had venous varices secondary to superior mesenteric vein thrombosis. Conclusions The vast majority of SCA patients demonstrate no noticeable arteriovascular abnormality on a contrast-enhanced CT of the abdomen. Diffuse intra-abdominal vasospasm is present in a very small percentage of SCA abdominal crisis patients.

Keywords

• Sickle cell anemia
• Vasculopathy
• Intra-abdominal arterial branches
• Vasculitis
• Moyamoya
• Abdominal crisis