POSTER SECTIONS Coverpage Learning objectives Background Findings and procedure details Conclusion Personal information and conflict of interest References

ECR 2020 / C-14758

Acute mesenteric ischemia: a case-based overview of imaging findings and their prognostic signisficance.

Congress:

ECR 2020

Poster Number:

C-14758

Type:

Educational Exhibit

Keywords:

Not applicable, Ischaemia / Infarction, Embolism / Thrombosis, Acute, Surgery, Diagnostic procedure, Complications, Ultrasound, CT, Conventional radiography, Mesentery, Gastrointestinal tract, Emergency, GI Tract

Authors:

M. A. Bereźniak¹, M. Deregowska-Cylke², R. Cylke², P. Ziemianski², W. Lisik², P. D. Palczewski², M. Golebiowski²; ¹Warszawa/PL, ²Warsaw/PL

DOI:

10.26044/ecr2020/C-14758

DOI-Link:

https://dx.doi.org/10.26044/ecr2020/C-14758

Fig. 15: Plain abdominal radiography in the preliminary evaluation of AMI.

Fig. 16: Plain abdominal radiograph shows dilated small bowel loops (A, supine view)...

Fig. 17: Left decubitus abdominal radiograph (A) with enlarged upper right quadrant (B)...

Fig. 18: PA erect abdominal radiograph shows subdiaphragmatic free gas (arrows) –...

Fig. 20: Ultrasound images showing dilated small bowel loops (>2,5 cm) with thickened...

Fig. 21: Ultrasound image shows pneumoportalis. Gas in the portal veins usually...

Fig. 22: Color Doppler US shows significantly elevated peak systolic velocity (PSV) in...

Table 3: Key CT findings for correct diagnosis various types of AMI. IVC, inferior vena...

Fig. 24: Dilated small bowel loops in a 74-year-old male with symptoms of intestinal...

Fig. 25: Same patient as Fig. 24. A: Plain abdominal radiograph (supine view) with...

Fig. 26: Same patient as Fig. 24. Axial contrast-enhanced CT scans show normal...

Fig. 27: Same patient as Fig. 24. Filling defects in the mesenteric vessles are...

Fig. 28: Same patient as Fig. 24. The normal small-bowel wall is thin and enhances (B,...

Fig. 29: A 85-year-old female with atrial fibrillation presented to the emergency...

Fig. 30: A 26-year-old male with history of previous abdominal surgeries presented to...

Fig. 31: Same patient as Fig. 30. Contrast-enhanced CT axial scans of the abdomen show...

Table 4: Findings of CT hypoperfusion complex.

Fig. 33: NOMI (secondary to hypotension) in a patient who suffered cardiac arrest during...

Table 5: The spectrum of CT findings and their etiology in AMI.

Table 6: Spectrum of imaging findings in AMI and common mimickers. IBD, inflammatory...

Table 7: Mortality of AMI based on Ernst Klar et al. [4].

Fig. 19: Ultrasound in the preliminary evaluation of AMI.

Fig. 23: Multidetector CT protocol for AMI

Fig. 32: A 22-year-old male with “shock bowel” after blunt abdominal trauma....

Fig. 34: Imaging findings associated with high risk of bowel necrosis. A: Axial CT scan...

Findings and procedure details

Multimodality approach.

Since neither the symptoms of AMI nor the results of laboratory tests are specific enough for the accurate and early diagnosis, imaging plays an important role in the diagnosis and management of patients with AMI. Initial evaluation of less severely ill patients presenting to the ER with abdominal symptoms often starts with plain abdominal radiography (Fig. 15-18) and ultrasound (Fig 19-22).

The well-established first-line imaging modality for diagnosis of suspected AMI is multidetector CT. MDCT is the most sensitive (93.3%) and specific (95.9%) diagnostic tool for AMI [7]. Biphasic contrast-enhanced CT should include the whole abdomen, in both the arterial and the venous phases (Fig. 23).

Key imaging findings and diagnostic difficulties.

CT findings (Fig. 24-33) may correlate with type of AMI (Tab. 3.), provide information about the underlying pathophysiology (Tab. 5.) and are useful in excluding other causes of acute abdominal pain.

Combination of different CT findings allows the diagnosis of AMI with high sensitivity and specificity, however several other conditions, both benign and malignant, may produce similar findings (Tab. 6.).

Prognosis.

The prognosis for patients with AMI depends on prompt diagnosis (Tab. 5) and the underlying cause. Non-occlusive mesenteric ischemia (NOMI) accounting for approximately 20-30% of all the cases of AMI is associated with the highest rates of in-hospital mortality [9,10].

Early diagnosis and treatment have been reported to be the most important factors affecting mortality [3,15].

At one year after hospital admission due to AMI, only 26% of patients will remain alive. Most deaths occur during hospitalization and patients who are discharged have a good prognosis with 84 % alive at one year and 50–77 % at five years [7]. Higher in-hospital mortality is associated with older age, accompanying cardiac disease, acute renal failure, and simultaneous large bowel ischemia [15,17].

The most important prognostic factor in patients with AMI is intestinal viability (intraoperatively estimated from the colour of the intestinal segment, arterial pulsation, presence of bowel peristalsis and bleeding from the marginal arteries). Resection of all regions of non-viable intestine should be performed without delay [10]. If the physical exam demonstrates signs of peritonitis, there is likely irreversible intestinal ischemia with bowel necrosis [2]. CT features suggestive of intestinal necrosis should be always highlighted in the radiology report (Fig. 34.).