Objective Vascular aberrancy of superior mesenteric artery (SMA) may contribute to the occurrence of SMA dissection. However, there is no direct evidence to support this hypothesis. Etiology, natural history, classification, and treatment options of ISMAD are still in controversial at some degree. We also review the current understanding of ISMAD based on our results.Methods Out of 57 patients, 2 cases of isolated superior mesenteric artery dissection (ISMAD) which concomitant with replaced common hepatic artery with SMA origin, are first reported.Results Two patients have no any typical etiological factors, such as atherosclerosis, hypertension, long-term smoking, and connective tissue disease. The contrast-enhanced computed tomography and (or) angiography showed concomitant SMA aberrancy. They have 81.2 degrees, 132.7 degrees SMA angle, respectively. After conservative treatment of 4, 6 days, respectively, these 2 patients were discharged smoothly.Conclusion Vascular aberrancy may be a new identified risk factor for ISMAD. Even in ISMAD cases with vascular aberrancy, conservative treatment still can be used as first line therapy.