Plasma i-FABP as Predictor for Irreversible Bowel Ischemia

In the FARAMIS study, we aim to investigate the longitudinal course of intestinal plasma fatty acid binding protein (i-FABP) in patients with acute mesenteric ischemia (AMI) undergoing primary percutaneous angiographic intervention.

The investigators postulate that patients with fully re-established intestinal blood flow and vital intestines will display a significant drop of plasmatic i-FABP within 24 hours, while patients requiring subsequent intestinal resection due to irreversible bowel necrosis will not.

If true, patients requiring laparotomy and bowel resection could be identified and patients in whom angiographic intervention led to successful cure of disease would not be exposed to potentially perilous surgery.

Intestinal plasma fatty acid binding proteins (i-FABP) have been introduced as a powerful marker for the diagnosis of intestinal ischemia. Based on several small studies, this marker is referred to as a sensitive indicator for intestinal ischemia. I-FABP is characterized by its short half-time of eleven minutes in blood circulation, which might allow "real-time" monitoring of necrotic intestinal segments.

Subjects meeting the in-/exclusion criteria will undergo five to six blood collections: one baseline assessment before revascularization, three assessments directly after angiographic intervention (5/30/120 minutes), and one assessment after 24 hours. An additional blood collection will be performed in patients who underwent subsequent surgery. In addition, clinical exams of the patient are carried out.

Subjects will be observed for 72 hours after percutaneous revascularization and retrospectively classified depending on the clinical course: recovering patients or patients undergoing surgery without signs of necrotic segments will be attributed to group A. Patients in whom intestinal necrosis is confirmed by surgery or autopsy will belong to group B. For all patients, clinical and laboratory findings will be reported in a descriptive manner.

To evaluate whether the post-interventional course of plasmatic i-FABP is a reliable predictor for successful revascularization, the minimum level of i-FABP at the time points 5, 30 and 120 Minutes is divided by the baseline (= before intervention) level of i-FABP. This ratio (R) reflects the decrease (or increase) of i-FABP after revascularization. Receiver operating characteristic (ROC)-analysis will be carried out and the area under the curve will be determined for different R-values (e.g. 0.3, 0.5, 0.7).

We postulate that patients with fully re-established intestinal blood flow and vital intestines will display a significant drop of plasmatic i-FAPB within 24 hours, while patients requiring subsequent intestinal resection due to irreversible bowel necrosis will not.

Eligibility Criteria:
Inclusion Criteria:

* Presence of acute mesenteric ischemia due to stenosis of the superior mesenteric artery, thromboembolization of the superior mesenteric artery, non-occlusive mesenteric ischemia or acute portal vein thrombosis (as confirmed by CT scan)
* The vascular anatomy is suitable for percutaneous revascularization
* A primary endovascular re-vascularisation approach is intended based on an interdisciplinary decision by the visceral surgeon, the vascular surgeon and interventional radiologist. This therapeutic decision is made independently of the proposed FARAMIS study.
* A peripheral or central line is present to perform repeated blood collections

Exclusion Criteria:

* Clinically or imaging results indicating that perforation of the bowel is present or suspected
* Hemodynamic instability (shock)
* Pre-existing severe liver or kidney damage (defined as spontaneous international normalized ratio \>2 or creatinine \>2 mg/dl.)
* Anemia with hemoglobin concentration \< 7g/dl
* Pediatric patients