Segmental Arterial Mediolysis and Associated Vascular Disorders
Summary
Segmental arterial mediolysis (SAM) is an uncommon non-atherosclerotic arteriopathy characterised by focal degeneration of the arterial media, most frequently involving medium-sized splanchnic vessels. The condition presents a spectrum of vascular lesions, including dissections, aneurysms, stenoses and occlusions, which may manifest as acute intra-abdominal haemorrhage or visceral ischaemia. Although its precise aetiology remains unclear, emerging evidence implicates dysregulated smooth muscle cell apoptosis and extracellular matrix remodelling as key drivers of medial lysis. Advances in multimodal imaging, notably computed tomography angiography and digital subtraction angiography, have enhanced early recognition, revealing transient vascular irregularities that can evolve unpredictably. Management strategies range from cautious observation with serial imaging to endovascular embolisation and open surgical repair, dictated by haemodynamic status and lesion anatomy. Long-term surveillance is essential, as new arterial lesions may develop beyond the initial presentation and systemic vascular involvement can arise over time. SAM overlaps clinically and radiologically with other arteriopathies such as fibromuscular dysplasia and vasculitis, emphasising the need for rigorous differential diagnosis and tailored multidisciplinary care.
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Segmental Arterial Mediolysis and Associated Vascular Disorders publication trend
The graph below shows the total number of articles in segmental arterial mediolysis and associated vascular disorders across all publications each year (not limited to Nature Index journals).
Technical terms
Segmental arterial mediolysis (SAM): A rare arteriopathy marked by focal loss of the arterial media, leading to dissections, aneurysms or haemorrhage without inflammation or atherosclerosis.
Splanchnic arteries: Vessels supplying abdominal organs, principally the celiac trunk, superior mesenteric artery and inferior mesenteric artery.
Aneurysm: Localised dilation of an arterial segment due to wall weakness, with potential risk of rupture.
Dissection: Separation of arterial wall layers allowing blood to enter a false lumen, which may compromise true lumen flow or rupture.
References
- A case of rectal cancer complicated with segmental arterial mediolysis (SAM) safely treated with curative resection - A case report. International Journal of Surgery Case Reports (2024).
- Hepatic segmental arterial mediolysis: A case report and brief literature review. Clinical Case Reports (2023).
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