Acute arterial mesenteric ischaemia: comparison of partial and complete occlusion of the superior mesenteric artery.

Abstract

Objectives: To describe the characteristics and outcomes of patients with an incomplete occlusion of the superior mesenteric artery (SMA) (persistence of contrast-enhanced vessel lumen) and compare them to those with a complete occlusion of the SMA (complete interruption of the contrast-enhanced vessel lumen) in arterial acute mesenteric ischaemia (AMI).

Material and methods: Retrospective study of arterial AMI patients (2006-2022). Demographics, laboratory tests, clinical characteristics, CT, treatments and outcomes were compared between patients with complete or incomplete SMA obstruction after adjusting for aetiology (embolic or atherosclerotic). The primary outcome was 30-day mortality, and the secondary outcome was 6-month gastrointestinal disability-free survival (no short bowel syndrome or parenteral nutritional support or permanent stoma).

Results: 151 patients (65 women, mean age 69) were included, 62 (41%) with incomplete and 89 (59%) with occlusive SMA occlusion. After adjusting for aetiology, chronic kidney failure (p = 0.03) and normal bowel enhancement on CT (p < 0.01) were associated with incomplete SMA occlusion. Patients with incomplete SMA occlusion were more frequently treated by endovascular revascularisation (p < 0.01) and stenting (p < 0.01), while patients with complete SMA occlusion were treated by open revascularisation. The 30-day mortality rate was 13% with no difference between incomplete (11%) and complete SMA occlusion (15%; p = 0.89). Nevertheless, complete SMA occlusion patients had a lower 6-month gastrointestinal disability-free survival rate (p = 0.01), more transmural necrosis (p < 0.01) and a higher risk of gastrointestinal disability (p = 0.02).

Conclusion: Incomplete SMA occlusion can cause AMI with a similar 30-day mortality rate to completely occlusive forms. However, it is associated with poorer gastrointestinal outcomes, regardless of aetiology.

Critical relevance statement: Acute arterial mesenteric ischaemia caused by incomplete occlusion of the superior mesenteric artery demonstrates similar 30-day mortality to complete occlusion but distinctively better gastrointestinal outcomes, emphasising nuanced imaging evaluation for targeted management strategies in these patients.

Key points: Occlusive acute mesenteric ischaemia can be caused by incomplete superior mesenteric artery (SMA) occlusion. Acute mesenteric ischaemia caused by incomplete SMA occlusion has a similar 30-day mortality rate to complete SMA occlusion. A complete occlusion of the SMA is associated with poorer gastrointestinal outcomes.