1. S ymptomatic mesenteric ischemia is an often delayed diagnosis with typically slow progressive complaints. Risk factors for chronic mesenteric ischemia are same as those for arteriosclerosis, such as diabetes, hyperlipidemia and previous surgeries. Given the anatomy of collateral circulation, significant multivessel mesenteric disease is required for clinical presentation. There is limited literature for direct measurements of mesenteric vessel pressures and induction of hyperemia using pressure wire technology. P ressure wire measurements yield an objective measure of vessel lesion and flow reserve standardized as a percentage under condition of induced hyperemia using agents such as adenosine. Pressure Wire and Fractional Flow Reserve (FFR) has been shown to be predictive of patient disease outcome especially in the setting of risk factors such as diabetes. The Fractional Flow Reserve (FFR) measurements in induced hyperemia correlate closely to the clinical picture and outcome in coronary arteries. It is a measure of physiologic pressure before and after a lesion and presented as a ratio. W e used an FFR value of 0.74 as a cutoff for normal arterial response Introduction: Use of Fractional Flow Reserve and Induction of Hyperemia in Evaluation of Mesenteric Ischemia Islam Abudayyeh MD MPH, Katayoun Seyedmadani PhD, Nabil Dib MD Division of Cardiology Advocate Lutheran General Hospital, Arizona State Univerity, Cardiovascular and Stem Cell Consultants Use of Fractional Flow Reserve and Induction of Hyperemia in Evaluation of Mesenteric Ischemia Islam Abudayyeh MD MPH, Katayoun Seyedmadani PhD, Nabil Dib MD Division of Cardiology Advocate Lutheran General Hospital, Arizona State Univerity, Cardiovascular and Stem Cell Consultants Clinical Case: A 76-year old man presented with seven year history of recurrent episodes of abdominal pain and intermittent bloody stools especially after large meals for the past one year. Given his progressive complaints the patient required admission for extensive evaluation. Of note, he had received radiation therapy of the abdomen seven year prior. P hysical exams, colonoscopy, and computed tomography failed to show any obvious cause for his continuing complaints. M agnetic Resonance Angiography revealed an area of patent narrowing at the origin of the celiac trunk with difficulty visualizing the inferior mesenteric artery. Methods: L eft heart catheterization demonstrated no significant angiographic disease M esenteric angiography demonstrated an ostial stenosis of the celiac trunk, and a mild stenosis of the superior mesenteric artery P ressure wire measurements were obtained of the celiac, superior mesenteric and inferior mesenteric arteries Conclusions:  M easurements of FFR are objectively predictive of the tissue perfusion, viability, and long-term outcome as demonstrated on laparotomy.  C onsidering this diagnosis and performing the evaluation with FFR early can help reduce morbidity and recurrence similar to evaluating coronary arteries.  T here no literature describing the use of FFR, or adequate induction of hyperemia in patients with mesenteric disease. Further studies are needed.  U se of pressure wire in non-coronary arteries is feasible and may help risk-stratify patients leading to earlier therapeutic options such as surgery, percutaneous intervention, or medical management. 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Prediction of in-stent restenosis by measurement of fractional flow reserve and the influence of diabetes mellitus. Journal of Cardiology. 2002 Vol 39(6) 293-298 15.lbertal, M.; Voskuil, M.; Piek, J. J.; de Bruyne, B.; etal. Coronary flow velocity reserve after percutaneous interventions is predictive of periprocedural outcome. Circulation. 2002 Vol 105(13) 1573-1578 Results:  T he celiac trunk had a 95% angiographic stenosis with baseline FFR 0.79. At maximum hyperemia FFR was below 0.71  T he superior mesenteric artery (SMA) had 90% stenosis with FFR of 0.84. At maximum hyperemia FFR was 0.78  T he inferior mesenteric artery (IMA) had 30% stenosis with baseline FFR of 0.92 T he patient became acutely ill the following day. Emergency laparotomy uncovered ischemic small intestine and proximal colon mainly at the distribution of the celiac and superior mesenteric arteries consistent with our angiographic findings. L eft colon at the distribution of IMA was unaffected. T he patient underwent extensive abdominal surgery, resection of the ischemic small bowel to the level of the ileum, and resection of the proximal third of the large bowel. Following the laparotomy the patient underwent abdominal angiography and stent placement at the ostium of the celiac trunk. Figure 1. Angiographic images showing the ostial stenosis of the celiac trunk (left) and pressure wire in the artery (right) Figure 4. Pressure tracings for the celiac trunk prior to adenosine infusion Figure 6. Celiac Trunk angiography and stent placement Figure 2. Superior mesenteric artery after infusion of adenosine showing a borderline response Figure 5. Pressure tracings for the celiac trunk after adenosine infusion demonstrating a significant pressure drop Patient History P eripheral infusion of Adenosine was given to induce hyperemia and improve the pressure wire diagnostic sensitivity Figure 3. Inferior mesenteric artery after infusion of adenosine showing a normal response, and no significant pressure drop