Acute Mesenteric Ischemia

Acute mesenteric ischemia (AMI) is a rare but life-threatening condition associated with high mortality and major diagnostic challenges due to nonspecific clinical presentation and limited reliable biomarkers. Critically ill patients in the intensive care unit (ICU) are at particularly high risk of non-occlusive mesenteric ischemia (NOMI), a subtype of AMI characterized by impaired mesenteric perfusion without large-vessel occlusion. Despite advances in imaging, the diagnosis of NOMI remains difficult, and data specifically focusing on ICU patients with suspected AMI are limited. This prospective observational multicenter study aims to identify independent predictors of transmural NOMI among ICU patients with suspected AMI. In addition, the study will describe demographics, comorbidities, clinical presentation, laboratory findings, diagnostic imaging, management strategies, and outcomes among ICU patients with NOMI, other forms of AMI, and patients with suspected but unconfirmed AMI. Consecutive adult ICU patients in whom clinical suspicion of AMI arises during ICU stay will be included across Estonian regional hospitals. The study is a local continuation of the international AMESI study, with a specific focus on critically ill ICU patients.

Acute mesenteric ischemia is a severe abdominal emergency associated with a poor prognosis. While numerous studies have been conducted on the incidence, outcomes, and risk factors of mesenteric ischemia, very few focus on the quality of life of patients.

The aim of the SURVIBIO study is to characterize accurate biomarkers for acute mesenteric ischemia, in particular at early stages. In the study, the development of biomarkers will be based on the analysis of human biological samples from patients and controls that will be conserved in a biological library. Samples will be analysed in the Laboratory for Vascular Translational Sciences (LVTS, Inserm U1148), in the Department of Biochemistry (Pr Puy, Dr Peoc'h), in Paris V university , in Imperial College of London (Pr Dumas), in Jacques Monod Institute and in Maastricht University Medical Center . The candidate markers will be determined according to an a priori method (form markers already described in the literature) and with no a priori strategy using -omics methods.

Acute mesenteric ischemia (AMI) is associated with high mortality (50-80%). The prognosis depends on the time it takes to diagnose the condition, and the possibility of revascularization in eligible patients. Delayed diagnosis is due in particular to the aspecific clinical presentation and the absence of biomarkers to guide early diagnosis, lactates often being elevated at an already irreversible stage. Adenosine deaminase is produced in the presence of ischemia (known from myocardial ischemia), and is present on the surface of intestinal villi. The investigator's hypothesis is that, in the event of digestive ischemia resulting in abnormalities of mesenteric permeability, adenosine deaminase will enter the bloodstream and increase its soluble plasma activity, along with an increase in lymphocyte-bound adenosine deaminase. The main objective is to evaluate the discriminatory capacities of soluble adenosine deaminase, collected via blood sampling, for the diagnosis of IMA in comparison with the reference method (injected abdominopelvic CT scan), performed for abdominal pain suggestive of IMA. The study will be based on a prospective monocentric cohort. Currently, there is no specific biological marker for IMA, and the gold standard for diagnosis is the injected abdominopelvic CT scan, performed for hyperintense abdominal pain. Two groups will be identified on the basis of the gold-standard abdominopelvic scan: * the "IMA patients" group: patients with hyperintense abdominal pain, and IMA confirmed by CT scan * the "non-IMA patients" group: patients with hyperintense abdominal pain, but with a diagnosis other than IMA on the CT scan. 130 subjects will be included in this study Inclusion period: 18 months Follow-up period: 1 month Analysis period: 5 months Total duration: 24 months

Computed tomography (CT) is the standard modality for scanning patients with critical acute abdominal conditions, including suspected acute mesenteric ischemia (AMI). CT imaging can potentially differentiate between reversible and irreversible ischaemic damage of the bowel. This moment is pivotal in selecting the treatment strategy for AMI - in the absence of irreversible damage; reperfusion therapy can preserve intestinal viability, thereby avoiding the need for bowel resection. The present study tests the hypothesis that combining several symptoms may enhance the diagnostic performance of CT scanning in detecting salvageable bowel in patients with AMI. This study is an ancillary component of the AMESI study (Clinical Trials: NCT05218863) - a prospective, multicentre observational study aimed at identifying the incidence and describing the outcomes of acute mesenteric ischemia (AMI) in adult hospitalized patients. The ultimate purpose of the present study is to create a computed tomography-based radiological score for the assessment of bowel viability in patients with AMI.

Acute mesenteric ischemia (AMI) is a life-threatening condition with an increasing incidence (7-13/100000 PY). The mortality of AMI is associated with the development and extent of transmural intestinal necrosis (IN), ranging from 25% without IN to 75% with IN. Given its potential reversibility, preventing the progression of AMI towards IN is now considered a primary therapeutic goal. Early management of AMI can thus avoid fatal outcomes and prevent lifelong complications such as short bowel syndrome. Following the results of a pilot study showing an improvement in survival and lower resection rates, our team created a first-of-its-kind intestinal stroke center (SURVI unit, Beaujon Hospital, Clichy, France) that provides 24/7 standardized multimodal and multidisciplinary care to AMI patients referred from all hospitals in the Paris region. As no randomized clinical trial has ever been conducted, the treatment offered by SURVI is based on pathophysiological knowledge and observational clinical data. AMI naturally progresses to sepsis, surgical complications, and multi-organ failure, direct consequences of IN. Features of sepsis are reported in up to 90% of AMI patients compared with 3-22% of patients with brain or myocardial ischemia, supporting a specific septic component in AMI. Experimental studies demonstrated reduced translocation and mortality in germ-free animals or after administration of oral antibiotics targeting Gram-negative and anaerobic early bacterial overgrowth and translocation. In a prospective observational study, the investigators recently suggested a protective effect of systematic oral antibiotics in terms of intestinal preservation, yielding a reduced occurrence of IN (HR: 0.16, 95% confidence interval 0.03-0.62). However, the systematic use of oral antibiotics in AMI remains controversial due to the individual and collective risk of increasing the carriage of multi-drug resistant bacterias.

Current study will be undertaken to identify combinations of biomarkers that can reliably identify acute mesenteric ischaemia (AMI) and distinguish between non-transmural and transmural ischaemia. Different combinations of biomarkers for different sub-types and severity of AMI, and different time points of measurement after onset of symptoms.