MDCT Imaging Features and Vasoconstrictor Impact in Non-Occlusive Mesenteric Ischemia

Overview

This study evaluated MDCT imaging findings in 90 patients with histopathologically confirmed NOMI and explored the influence of vasoconstrictor agents (VCAs) on vascular and intestinal features. Severe vasoconstriction of the superior mesenteric artery (SMA) and its branches was more pronounced in patients receiving VCA support, correlating with distinct MDCT vascular signs.

Background

Acute mesenteric ischemia (AMI) is a critical condition with high mortality, particularly in ICU patients. Non-occlusive mesenteric ischemia (NOMI), a subtype of AMI caused by splanchnic hypoperfusion and vasoconstriction, accounts for 20–30% of acute bowel ischemia cases and carries a mortality rate of 70–90%. Diagnosis is challenging due to nonspecific clinical signs and laboratory markers, with MDCT increasingly used for early detection. Vasoconstrictor agents, commonly administered in shock states, may exacerbate mesenteric vasoconstriction and influence imaging findings.

Data Highlights

Key Findings

• MDCT revealed severe spasm and irregularity of the main SMA and its branches in NOMI patients receiving vasoconstrictor agents.
• Patients without VCA support showed less pronounced vascular vasoconstriction on MDCT imaging.
• Vascular signs included narrowing at SMA branch origins, 'beading' or 'string-of-sausage' appearance, and spasm of mesenteric arcades.
• MDCT can detect both vascular and bowel wall changes indicative of NOMI, aiding early diagnosis.
• Histopathology served as the reference standard confirming NOMI in all patients undergoing bowel resection.

Clinical Implications

MDCT is a valuable non-invasive tool for early detection of NOMI, especially in critically ill patients receiving vasoconstrictor therapy. Awareness of the impact of VCAs on mesenteric vasculature can improve interpretation of imaging findings and prompt timely surgical intervention. Clinicians should consider the intensity of vasoconstrictor use when evaluating MDCT signs of mesenteric ischemia.

Conclusion

MDCT imaging effectively identifies vascular and intestinal changes in NOMI, with vasoconstrictor agents intensifying mesenteric arterial vasospasm. Early recognition of these imaging features is critical to improving outcomes in this high-mortality condition.

References

1. Siegelman et al 1980 -- Angiographic criteria for mesenteric arterial vasoconstriction
2. STROBE guidelines 2007 -- Strengthening the Reporting of Observational Studies in Epidemiology
3. Multiple sources 2010-2018 -- Imaging and clinical features of NOMI