Acute mesenteric ischemia. Profile of an aggressive disease
Acute mesenteric ischemia is an abdominal emergency due to inadequate tissue perfusion with a mortality rate between 60 and 100%. Intestinal damage by ischemia depends on general circulation, collateral blood flow, response of the mesenteric vasculature to autonomic stimuli, circulating vasoactive substances, local humoral factors, and the normal and abnormal products of cellular metabolism before and after reperfusion of the ischemic segment. Four physiopathologic phenomenon are present: superior mesenteric artery embolism; superior mesenteric artery thrombosis; non-occlusive acute mesenteric ischemia, and superior mesenteric venous thrombosis; embolism event is the most frequent. The injury observed after 3 of ischemia (blood flow reduced to 20% of normal) and 1 of reperfusion is more severe than 4 of ischemia. Clinical diagnosis of mesenteric ischemia required a high suspect index, specially in elderly patients with cardiovascular problems. Abdominal pain and hemodynamic and/or metabolic changes are the most frequent symptoms. Although some authors have questioned the need for angiography, this study is the key not only to making a diagnosis of acute mesenteric ischemia before bowel infarction and prior to laparotomy, but also to initiate intra-arterial mesenteric angiography therapy with vasodilators. Patients who persist with acute abdomen will require exploratory celiotomy and vascular exploration. The outcome depends on early diagnosis and therapy to avoid ischemia progression and reperfusion injury.