Angiographic analysis of the variation of arterial collaterals in moyamoya and atherosclerosis at a tertiary care center in Saudi Arabia

OBJECTIVES: To evaluate the anatomical variation of arterial collaterals and their prevalence in moyamoya and atherosclerosis. METHODS: Data was collected retrospectively from patients (n=46) database who underwent digital subtraction angiography between January 2010 and December 2018 at the Radiology Department, King Fahad Medical City, Riyadh, Saudi Arabia. Demographic details and clinical data of the patients such as age, gender, etiology, clinical presentation, angiographic staging using Suzuki grading for moyamoya cases, variation of arterial collaterals, and their prevalence, treatment and follow up were obtained. RESULTS: Four types of collaterals network were observed in atherosclerosis (n=21) and moyamoya (n=25); the leptomeningeal, durocortical, subependymal, inner-interstriatal and intrathalamic networks. More number of collaterals were observed in the moyamoya (n=534) than atherosclerosis (n=40). Leptomeningeal network (n=198, 37.1%) and subependymal network (n=170, 31.8%) were greater than durocortical and inner-interstriatal or intrathalamic in patients with moyamoya. Whereas leptomeningeal network (n=25, 62.5%) and inner-interstriatal or intrathalamic (n=7, 17.5%) were predominant in atherosclerosis. Out of 25 cases of moyamoya, Suzuki grading V was noted in 5 (20%) and grade IV in 13 (52%). CONCLUSION: Understanding the dynamics that have evolved in the development of the collaterals and therefore can improve both management and prognosis.