Sandbox:Feham

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Feham Tariq, MD [2]

Overview

Mesenteric ischemia is a type of intestinal ischemia primarily affecting the small intestine. It is one of the life-threatening gastrointestinal vascular emergencies which requires prompt surgical/medical intervention depending upon the underlying cause.

Common causes in the development of mesenteric ischemia can be divided into occlusive/non-occlusive, arterial or venous, localized/generalized and superficial or transmural.

Risk Factors

Common Risk Factors

Risk factors
Occlusive	Embolic	Atrial fibrillation
		Cardiac arrhythmia
		Valvular heart disease
		Infective endocarditis
		Recent myocardial infarction
		Ventricular aneurysm
		Aortic atherosclerosis
	Thrombotic	Advanced age
		Low cardiac output states
		Peripheral arterial disease
		Traumatic injury
		Inherited thrombophilia- Factor V Leidin mutation Prothrombin G20210A mutation Protein S deficiency Antithrombin III deficiency Activated protein C resistance Anti-phospholipid syndrome Myeloproliferative disorders(JAK2 V617F) mutation.
		Acquired thrombophilia- malignancy, oral contraceptives intake.
Non-occlusive		Heart failure
		Aortic insufficiency
		Septic shock
		Vasoconstrictive drugs: Digoxin Alpha-adrenergic agonists
		Cocaine abuse or ergot poisoning
		Hemodialysis
Other causes		Lifestyle related risk factors: High cholesterol levels History of smoking Immobility Recent surgery Less common risk factors: Fibromuscular dysplasia Beta receptor blocking agents Hepatitis

• Common risk factors in the development of mesenteric ischemia include:
  • Occlusive causes
    • Embolic causes:
    • Atrial fibrillation
    • Cardiac arrhythmias
    • Valvular heart diseases
    • Infective endocarditis
    • Recent myocardial infarction
    • Ventricular aneurysm
    • Aortic atherosclerosis
    • Aortic aneurysm
  • Thrombotic causes:
    • Advanced age
    • Low cardiac output states
    • Traumatic injury
    • Peripheral artery disease
• Non-occlusive causes:
  • Heart failure
  • Aortic insufficiency
  • Septic shock
  • Vasoconstrictive drugs(e.g. Digoxin, alpha-adrenergic agonists)

• • Cocaine abuse or ergot poisoning

• • Hemodialysis

Less Common Risk Factors

• Less common risk factors in the development of mesenteric ischemia include:
  • Fibromuscular dysplasia
  • Hepatitis
  • Beta recpetor blocking agents

Causes

Narrowing of the arteries that supply blood to the intestine causes mesenteric ischemia. The arteries that supply blood to the intestines run directly from the aorta. Mesenteric ischemia is often seen in people who have hardening of the arteries in other parts of the body (for example, those with coronary artery disease or peripheral vascular disease). The condition is more common in smokers and in patients with high blood pressure or blood cholesterol. Mesenteric ischemia may also be caused by an embolus that suddenly blocks one of the mesenteric arteries. The emboli usually come from the heart or aorta. These clots are more commonly seen in patients witharrhythmias, such as atrial fibrillation. The most commom cause of mesenteric ischemia is superior mesneteric artery occlusion. They can be broadly classified into four categories:

• Arterial thrombosis
• Arterial embolism
• Venous thrombosis
• Non-occlusive ischemia

Classification based on etiology
Etiology	Cause	Incidence	Examples
Occlusive causes	Aterial embolism	50-70%	Arrhythmia Myocardial infarction Infective endocarditis Valvular heart diseases Ventricular aneurysms History of embolic events Recent angiography
	Arterial thrombosis	15-25%	Advnaced age Prlonged hypotension Hypercoagulabilty states Estrogen Peripheral arterial disease Traumatic injury
	Venous thrombosis	5%	Right-sided heart failure Previous deep venous thrombosis Primary clotting disorder Pancreatitis Polycythemia Sickle cell anemia Recent abdominal surgery or infection
Non-Occlusive causes	Non-occlusive ischemia	20-30%	Hypovolemia Low cardiac output states Vasoconstrictive drugs (Digoxin, alpha-adrernergic agonists) Septic schock Aortic insufficiency Cocaine abuse or ergot poisoning

Life-threatening Causes[edit | edit source] Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated. There are no life-threatening causes of disease name, however complications resulting from untreated disease name is common. Life-threatening causes of [symptom/manifestation] include [cause1], [cause2], and [cause3]. [Cause] is a life-threatening cause of [disease]. Common Causes[edit | edit source] [Disease name] may be caused by: