"Segmental arterial mediolysis (SAM) is an increasingly recognised vascular disease of the middle-aged and elderly and a leading cause of spontaneous intra-abdominal haemorrhage. It is characterised by fusiform aneurysms, stenoses, dissections and occlusions within splanchnic arterial branches. Imaging is not only the key to the diagnosis of this condition, but can also facilitate life-saving endovascular therapy."
"Segmental arterial mediolysis is an uncommon arteriopathy, which is not atherosclerotic or inflammatory. The underlying histological process is lysis of the smooth muscle of the outer media of the arterial wall 5, resulting in intramural haemorrhage, saccular or dissecting aneurysms, thrombosis and haemorrhage. It affects the visceral arteries of the abdomen in a skip pattern 6, most commonly affecting the medium size branches of the superior mesenteric artery. The aetiology is unknown, but an association with episodes of splanchnic vasoconstriction has been observed (e.g. shock, hypoxia, recent major operation, vasopressor infusion) 5,7. There is some histological similarity to fibromuscular dysplasia, which is a differential diagnosis, but the clinical features and lesion distribution are usually characteristic."
"Segmental arterial mediolysis is an uncommon arteriopathy, which is not atherosclerotic or inflammatory. The underlying histological process is lysis of the smooth muscle of the outer media of the arterial wall 5, resulting in intramural haemorrhage, saccular or dissecting aneurysms, thrombosis and haemorrhage. It affects the visceral arteries of the abdomen in a skip pattern 6, most commonly affecting the medium size branches of the superior mesenteric artery. The aetiology is unknown, but an association with episodes of splanchnic vasoconstriction has been observed (e.g. shock, hypoxia, recent major operation, vasopressor infusion) 5,7. There is some histological similarity to fibromuscular dysplasia, which is a differential diagnosis, but the clinical features and lesion distribution are usually characteristic."
"Segmental arterial mediolysis is an uncommon arteriopathy, which is not atherosclerotic or inflammatory. The underlying histological process is lysis of the smooth muscle of the outer media of the arterial wall 5, resulting in intramural haemorrhage, saccular or dissecting aneurysms, thrombosis and haemorrhage. It affects the visceral arteries of the abdomen in a skip pattern 6, most commonly affecting the medium size branches of the superior mesenteric artery. The aetiology is unknown, but an association with episodes of splanchnic vasoconstriction has been observed (e.g. shock, hypoxia, recent major operation, vasopressor infusion) 5,7. There is some histological similarity to fibromuscular dysplasia, which is a differential diagnosis, but the clinical features and lesion distribution are usually characteristic."
"A pattern of aneurysms and stenoses in series is characteristic; the "string-of-beads" appearance. The aneurysms have a random distribution, in contrast to mycotic aneurysms which show a predilection for bifurcations 6. Dissections may occur but are rare in splanchnic branches."