What is mesenteric ischemia?

From the Guidelines

Mesenteric ischemia is a serious medical condition characterized by insufficient vascular supply to the small bowel, which can lead to life-threatening bowel infarction with associated mortality rates that approach 60%. The term "mesenteric ischemia" refers to a group of diseases that result from an interruption of the blood supply to varying portions of the intestine, leading to ischemia and secondary inflammatory changes 1. The causes of mesenteric ischemia can be broadly divided into mesenteric arterial occlusion, including atherosclerotic disease, anatomical causes such as median arcuate ligament (MAL) syndrome, thromboembolism, and vasospasm, mesenteric venous occlusion, and global hypoperfusion, including hypotension and shock 1.

Some key points to consider in the diagnosis and management of mesenteric ischemia include:

• Delays in diagnosis and intervention can lead to life-threatening bowel infarction with associated mortality rates that approach 60% 1
• CT of the abdomen and pelvis should be performed in the non-contrast, arterial and portal venous phases to identify the underlying cause of ischemia, evaluate for possible bowel complications, and exclude other potential diagnoses of acute abdominal pain 1
• Endovascular approaches, including thrombolysis and clot retrieval, percutaneous transluminal angioplasty (PTA), and stent placement, are commonly attempted first, and traditional surgical approaches are resorted to when endovascular treatment fails or is not feasible 2
• The use of endovascular approaches has been associated with a decrease in the amount of bowel resected, lower incidence of concomitant renal or respiratory failure, lower subsequent incidence of short bowel syndrome, and lower mortality 2

The primary goal of treatment is rapid restoration of inline arterial flow to the affected bowel to avoid potentially life-threatening complications. In addition to volume resuscitation, empiric antibiotic therapy, and anticoagulation, rapid restoration of inline arterial flow to the affected bowel is the primary goal of treatment to avoid potentially life-threatening complications 3.

It is essential to note that as many as 70% of patients may need surgical intervention for bowel resection and/or diversion with or without any intervention 3. The results of small studies show a wide range of mortality data that can be difficult to interpret, but larger cohort studies generally support improved short-term mortality rates with endovascular therapy compared with surgical management 3.

In terms of mortality, the literature comparing endovascular and surgical approaches remains mixed, but a systematic review and meta-analysis including 3,362 patients found that endovascular interventions had a lower 30-day mortality (odds ratio, 0.45; 95% confidence interval [CI], 0.30-0.67; P ¼ .0001) compared with surgical interventions 3.

Overall, mesenteric ischemia is a serious medical condition that requires prompt diagnosis and treatment to prevent life-threatening complications. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment to reduce the high mortality associated with this entity 4.

From the Research

Definition and Classification of Mesenteric Ischemia

• Mesenteric ischemia is a rare, frequently misdiagnosed, serious condition that carries with it a high rate of morbidity and mortality 5.
• It is classified as either acute or chronic, with acute mesenteric ischemia being a life-threatening emergency that may ultimately result in bowel infarction 6.
• Mesenteric ischemia can be caused by arterial embolism, arterial thrombosis, non-occlusive mesenteric ischemia, and mesenteric venous thrombosis 5, 6.

Clinical Presentation and Diagnosis

• The presentation of mesenteric ischemia depends on the underlying pathophysiology, with arterial embolic disease presenting with sudden, severe pain, and other forms presenting with vague symptoms such as generalized abdominal pain, weight loss, vomiting, and diarrhea 5.
• Laboratory testing can suggest the disease with leukocytosis and elevated lactate, but normal values should not be used to exclude the diagnosis 5.
• Imaging modalities, such as triple phase computed tomography with non-contrast, arterial, and delayed phases, play a key role in the diagnosis of mesenteric ischemia 5, 7, 8.

Management and Treatment

• The initial management of mesenteric ischemia includes fluid resuscitation, symptomatic therapy, broad-spectrum antibiotics, and anticoagulation 5.
• Emergent consultation with a multidisciplinary team, including diagnostic and interventional radiologists and cardiovascular and general surgeons, is necessary for definitive treatment 5.
• Endovascular interventions appear superior to open surgical management with lower mortality, morbidity, and cost of care in appropriate populations 7.
• The management of mesenteric ischemia relies on a combination of medical protocol, revascularization of viable bowel, and surgical resection of necrotic tissue 8.