Reperfusion in non-occlusive mesenteric ischaemia (NOMI): effectiveness of CT in an emergency setting

Abstract

Objective: To investigate the CT features of reperfusion (presence/absence) in non-occlusive mesenteric ischaemia (NOMI) and their prognostic value in an emergency setting. Methods: A revision was undertaken of imaging from 20 patients (16 males/4 females) with a dismissal summary of NOMI. All patients had previously undergone a minimum of one multidetector CT examination, and consequently underwent surgery (n 5 8), autopsy (n 5 2), angiography (n 5 1) or endoscopy (n 5 9). An evaluation of the CT scans was conducted to determine vessels, mesentery, bowel and peritoneal cavity features. The superior mesenteric artery (SMA) average diameter of NOMI cases were compared with 30 controlled cases. Kappa, KolmogorovSmirnov (K-S) and Fisher's exact tests were used for statistical analysis. Results: A mean SMA diameter significantly smaller than that of the controlled cases was found for patients with NOMI (K-S test: D 5 0.75, p 5 3.7 3 10-08). Fisher's exact tests showed a strong connection between the presence of reperfusion and mesenteric fat stranding (p 5 0.026), bowel wall thickening (p 5 3.2 3 10-05) and a high attenuation of the bowel wall on unenhanced CT images (p 5 2.8 3 10-04). A reduction in mortality was significantly linked to the combination of normal mesenteric vessels and wall thickening (p 5 0.034). Conclusion: Analysis of not only vessels findings but also mesentery and bowel CT features will support the identification of NOMI with or without a reperfusion event in an emergency setting. A strong correlation between some CT features and lower mortality exists. Advances in knowledge: CT features of NOMI with or without reperfusion are demonstrated. Correctly assessing the presence of reperfusion in NOMI, may allow better management of these conditions in the emergency setting. INTRODUCTIONNon-occlusive mesenteric ischaemia (NOMI) is an abdominal emergency that accounts for 20-30% of all intestinal ischaemic events.1 Bowel ischaemia and infarction in NOMI are present as a result of reduced mesenteric blood supply without vascular occlusion, because of a mesenteric arterial vasoconstriction on reflex to hypotension owing to various forms of shock, septicaemia, dehydration, heart or major abdominal surgery followed by hypotension and overuse of vasoconstrictive agents.

The role of multislice computed tomography (MSCT) angiography in the diagnosis and therapy of non-occlusive mesenteric ischemia (NOMI): Could MSCT replace DSA in diagnosis?

“…Other secondary signs—examined separately—were deemed insufficient for diagnosing NOMI in MSCT. Other reports suggest that they could offer greater confidence in the diagnosis [ 24 , 27 , 28 ] of NOMI, but in the authors’ opinion cannot be regarded as a single specific indicator. A definite, but small (R1 = 0.31; R2 = 0.29) and not significant (R1 p = 0.10; R2 p = 0.12) correlation was found for reduced contrast enhancement of the bowel wall, as the best of the secondary signs.…”

“…Additionaly, as postulated by Mazzei et al, CT could reveal the different appearances of NOMI upon imaging depending on the time at which the CT examination is performed and thus, on presence or absence of reperfusion. [ 27 ]…”

Use of indocyanine green fluorescence imaging to determine the area of bowel resection in non-occlusive mesenteric ischemia: A case report

“…NOMI is very rare clinical condition, but it has a very high mortality rate of 30–68.5% even now [ [4] , [5] , [6] , [7] ]. The pathogenesis of NOMI is vasospasm of mesenteric arteries, and the blood flow is not completely interrupted in contrast to superior mesenteric artery occlusion [ 8 ].…”

Atherosclerosis is associated with poorer outcome in non-occlusive mesenteric ischemia

“…Non-occlusive mesenteric ischemia (NOMI) accounts for 20-30 % of all acute mesenteric ischemia [1], and has a high mortality rate (50-83 %) [2]. NOMI is a form of acute mesenteric ischemia that is caused by splanchnic hypoperfusion without digestive vascular occlusion [1], reflecting intense splanchnic vasoconstriction [3,4], commonly caused by shock, hemorrhage, surgery, dialysis, hypovolemia, cardiogenic injuries, vasoactive treatments, or intoxication [5]. The diagnosis of NOMI remains challenging, and previous studies have indicated that the diameter of the superior mesenteric artery could be of help in the diagnosis [6,7].…”

“…The diagnosis of NOMI remains challenging, and previous studies have indicated that the diameter of the superior mesenteric artery could be of help in the diagnosis [6,7]. However, the diagnosis of NOMI relies mainly on evidence of bowel injury, which may be difficult to interpret in case of reperfusion [4,6,9]. Beyond the diagnosis of NOMI, the prognosis of patients suffering for NOMI prognosis is poor, and is not well understood, depending on various factors, such as disease severity, sepsis, shock and multiple organ failure.…”