Acute Mesenteric Ischemia

Abstract

Background: Despite constant improvements in diagnostic as well as interventional and surgical techniques, acute mesenteric ischemia (AMI) remains a life-threatening emergency with high mortality rates. The time to diagnosis of AMI is the most important predictor of patients' outcome; therefore, prompt diagnosis and intervention are essential to reduce mortality in patients with AMI. The present review was performed to analyze potential risk factors and to help find ways to improve the outcome of patients with AMI.

Summary: Whereas AMI only applies to approximately 1% of all patients with an "acute abdomen," its incidence is rising up to 10% in patients >70 years of age. The initial clinical stage of AMI is characterized by a sudden onset of strong abdominal pain followed by a painless interval. Depending on the extent of disease, the symptoms of nonocclusive mesenteric ischemia (NOMI) and patients with a venous thrombosis can be very different from those of acute occlusive ischemia. Biphasic contrast-enhanced CT represents the gold standard for the diagnosis of arterial and venous occlusion. In case of a central occlusion of the superior mesenteric artery or signs of peritonitis, immediate surgery should be performed. If major bowel resection becomes necessary, critical residual intestinal length limits must be kept in mind. Endovascular techniques for arterial occlusion have taken on a much greater importance today. For stable patients with NOMI, interventional catheter angiography is recommended because it enables diagnosis and treatment with selective application of vasodilators. Depending on its degree, interventional treatment with a transhepatic catheter lysis should be considered for acute and chronic portal vein thrombosis.

Key message: The prompt and targeted use of the appropriate diagnostics and interventions appears to be the only way to reduce the persistently high mortality rates for AMI.

Keywords: Acute mesenteric ischemia; Critical care; Diagnosis; Diagnostic imaging; Endovascular procedures; Mortality; Portal vein thrombosis; Surgery.

Fig. 1

Clinical manifestation and course of AMI with loss of time due to routine diagnostics. With kind permission from Georg Thieme Verlag KG, Stuttgart, Germany − modified from [2].

Fig. 2

Diagnostic algorithm in case of unspecific abdominal pain versus suspected AMI.

Fig. 3

A Intraoperative exposition of the SMA, occluded with an embolus in a patient with AMI. B, C Incision of the SMA prior to embolectomy.

Fig. 4

Critical length of remaining small bowel after resection. A 100 cm in case of terminal jejunostomy (colon removed). B 65 cm in case of a jejuno-colonic anastomosis (colon retained). C 35 cm in case of a jejuno-ileal anastomosis (ileo-cecal region retained). Reproduced with kind permission from Georg Thieme Verlag KG, Stuttgart, Germany − modified from [2].

Fig. 5

Endovascular therapeutic options for hemodynamically stable patients with no signs of peritonitis.

Fig. 6

NOMI after cardiac surgery before and after intra-arterial Prostavasin infusion. NOMI: non-occlusive mesenteric ischemia. Reproduced with kind per­mission from “Deutsches Ärzteblatt,” Deutscher Ärzte-Verlag GmbH, Cologne, Germany − modified from [1].

Fig. 7

Portal vein thrombosis before and 7 days after ante- and retrograde catheter lysis. reproduced with kind permission from Georg Thieme Verlag KG, Stuttgart, Germany − modified from [2].