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Spontaneous intrahepatic haemorrhage: two cases of segmental arterial mediolysis
Lachlan Marshall1, Thomas O'Rourke, Andrew McCann
1Department of Surgery, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
Background:
Segmental arterial mediolysis (SAM) is an under-recognized degenerative vascular disorder with variable clinical presentations. It affects medium to large calibre arteries, typically those arising from the coeliac axis, and its diagnosis is complicated by overlap with other clinical entities like fibromuscular dysplasia. Diagnosis requires histopathological examination of the affected tissue, although radiographic appearances can be suggestive of SAM.
Methods:
We report on two patients presenting with acute rupture of an intrahepatic artery affected by SAM.
Results:
Both patients ultimately required right hemi-hepatectomy in order to either control ongoing bleeding or for removal of liver rendered ischaemic by intra-arterial embolization. This was achieved safely despite additional SAM lesions present throughout the vasculature.
Conclusion:
In both cases described, presentation followed recent, unrelated abdominal surgery and we propose a link between these two events. Recent research has identified the potential role of noradrenaline in the development of SAM lesions in greyhounds, with levels of endogenous noradrenaline known to rise in the setting of surgery.
Insights
Segmental arterial mediolysis (SAM) can cause dangerous intrahepatic artery ruptures, often requiring surgery. Post-operative stress may trigger SAM, suggesting a link between surgery and this vascular condition.
Area of Science:
- Vascular Medicine
- Degenerative Vascular Disorders
- Surgical Complications
Background:
- Segmental arterial mediolysis (SAM) is an under-recognized degenerative vascular disease affecting medium to large arteries.
- Diagnosis is challenging due to overlapping symptoms with conditions like fibromuscular dysplasia, requiring histopathological confirmation.
- Radiographic findings can suggest SAM, but definitive diagnosis relies on tissue examination.
Observation:
- This report details two cases of acute intrahepatic artery rupture caused by SAM.
- Both patients presented with severe bleeding or ischemia necessitating surgical intervention.
Findings:
- Right hemi-hepatectomy was required in both cases to manage bleeding or remove ischemic liver tissue.
- Surgical intervention was successful despite the presence of additional SAM lesions in other vasculature.
- A potential link between recent abdominal surgery and the onset of SAM is proposed, possibly related to elevated noradrenaline levels.
Implications:
- Highlights the critical nature of SAM and its potential for catastrophic vascular events.
- Suggests a possible iatrogenic or stress-induced component to SAM development, particularly post-surgery.
- Emphasizes the need for increased awareness and diagnostic vigilance for SAM in patients with relevant vascular complications after surgery.
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