Evaluating the Risk of Irreversible Intestinal Necrosis Among Critically Ill Patients With Nonocclusive Mesenteric Ischemia

Abstract

INTRODUCTION: To identify factors associated with irreversible transmural necrosis (ITN) among critically ill patients experiencing nonocclusive mesenteric ischemia (NOMI) and to compare the predictive value regarding ITN risk stratification with that of the previously described Clichy score. METHODS: All consecutive patients admitted to the intensive care unit between 2009 and 2019 who underwent exploratory laparotomy for NOMI and who had an available contrast-enhanced computed tomography with at least 1 portal venous phase were evaluated for inclusion. Clinical, laboratory, and radiological variables were collected. ITN was assessed on pathological reports of surgical specimens and/or on laparotomy findings in cases of open–close surgery. Factors associated with ITN were identified by univariate and multivariate analysis to derive a NOMI-ITN score. This score was further compared with the Clichy score. RESULTS: We identified 4 factors associated with ITN in the context of NOMI: absence of bowel enhancement, bowel thinning, plasma bicarbonate concentration ≤15 mmol/L, and prothrombin rate <40%. These factors were included in a new NOMI-ITN score, with 1 point attributed for each variable. ITN was observed in 6%, 38%, 65%, 88%, and 100% of patients with NOMI-ITN score ranging from 0 to 4, respectively. The NOMI-ITN score outperformed the Clichy score for the prediction of ITN (area under the receiver operating characteristics curve 0.882 [95% confidence interval 0.826–0.938] vs 0.674 [95% confidence interval 0.582–0.766], respectively, P < 0.001). DISCUSSION: We propose a new 4-point score aimed at stratifying risk of ITN in patients with NOMI. The Clichy score should be applied to patients with occlusive acute mesenteric ischemia only.

Abdominal atherosclerosis is not a risk factor of nonocclusive mesenteric ischemia among critically ill patients: a propensity matching study

“…Then, a relatively high proportion of our cohort (i.e., 24/59; 41%) did not have surgical or endoscopic confirmation of NOMI due to their poor prognosis. However, our group previously identified reliable CT findings of NOMI [ 7 , 18 ], and we believe that the risk of underdiagnosis of NOMI remains low (Specificity of absence of enhancement range from 79 to 97% according to the bowel segment involved [ 22 ]). Because of the time required by the calculation of abdominal calcium scores, the number of patients in the study is relatively limited.…”

“…NOMI was defined as the evidence of bowel ischemic injury at surgical exploration or digestive endoscopy in the absence of acute mesenteric vessel obstruction. In patients without surgical or endoscopic exploration, NOMI was diagnosed when abdominal CT showed evidence of ischemic bowel injury: absence of enhancement of the bowel wall ± thinned wall for small bowel involvement [ 7 ] and absence of enhancement of the bowel wall for the colonic involvement [ 22 ].…”

“…Abdominal computed tomography (CT) remains the cornerstone of NOMI diagnosis, allowing the diagnosis of bowel transmural necrosis [ 7 ] and providing prognostic elements for these patients [ 16 ]. CT also allow quantification of atheroma by detecting vascular calcifications which has been extensively studied in the coronary arteries [ 17 , 18 ] by the Agatston method.…”

“…Triggering factors of NOMI are not so well known. It is considered that the severity of shock per se could lead to NOMI among critically ill patients [7][8][9]. Hence, duration of low flow state and catecholamine infusion are established risk factors of NOMI.…”

Letter to the editor: Pneumatosis in bowel ischemia: time to change the optics to improve patient care

“…2 ). In our recent study [ 7 ] of 154 patients with NOMI undergoing laparotomy, 81 underwent surgical exploration for suspected small bowel transmural necrosis. Among them, 31 (31/81, 38%) had gas pattern at CT. At the end, among these 31 patients with suspected small bowel NOMI associated with gas pattern, none of the patients (0/4) with normal wall enhancement had transmural necrosis.…”