Intestinal ischemia also called visceral or mesenteric ischemic syndrome, is the term used to describe the result of a variety of disorders that cause insufficient blood flow to the gastrointestinal tract. Such ischemic injuries can manifest with symptoms ranging from a mild bout of short-lived abdominal pain, to bloody diarrhea or a more serious situation that may require surgery and even end in death.
The three major abdominal blood vessels that may become blocked include the celiac artery, superior mesenteric artery or inferior mesenteric artery. Usually two or three of these arteries must be narrowed or blocked to cause intestinal ischemic syndromes.
In general terms, ischemia either can be localized to a relatively small part of the small intestine or colon, or it may be more widespread and involve significant portions of both.
The time course of the ischemic event also may vary and be acute (new), chronic (long-standing), or recurrent.
An ischemic problem may be caused by an interruption in blood passage through an artery (a blood vessel that brings blood to the intestines) or vein (a blood vessel that returns blood from the intestines to the heart). There are several ways in which arterial blood supply to the intestines can be restricted: an embolus (a migrating blood clot that can form a blockage), a thrombus (a stationary clot attached to the wall of a blood vessel that can prohibit blood passage), or a so-called non-occlusive state (spasm of a blood vessel, but without permanent obstruction, that restricts blood flow through an artery).
Venous problems also may result in intestinal ischemia, although less commonly than arterial causes. The most common cause of ischemia from venous obstruction is a thrombus which interferes with the return of blood flow from the intestines, produces intestinal congestion, and results in intestinal swelling, and occasionally bleeding.
Causes
Acute Intestinal Ischemia: The arteries supplying oxygen-rich blood and nutrients to your intestines can become narrowed from atherosclerosis in the same way that coronary (heart) arteries become narrowed in heart disease. Mesenteric ischemia can develop if the narrowing or blockage become severe.
Another cause of acute ischemia is a blood clot. If a blood clot forms or travels to the narrowed artery, the blood supply to the intestine is suddenly interrupted. The tissues below the blocked vessel will be starved for oxygen-rich blood and die. This event is a life-threatening condition.
Chronic Intestinal ischemia is characterized by narrowing of the blood vessels that supply the intestines with nutrients and oxygen-rich blood. This narrowing also is caused by atherosclerosis (buildup of fatty matter and plaque on the blood vessel walls). Chronic mesenteric ischemia is more common in women than men, and occurs after age 60.
A potentially dangerous complication of chronic mesenteric ischemia is the development of a blood clot within a diseased artery, causing blood flow to be suddenly blocked (acute mesenteric ischemia).
Risk Factors
- Smoking
- Diabetes
- Hypertension (high blood pressure)
- High lipid values (cholesterol, LDL, triglycerides)
Symptoms
Early signs and symptoms of acute intestinal ischemia include –
- Severe abdominal pain, concentrated in one area of the abdomen
- Nausea and/or vomiting
- Bloody stools
- History of chronic atrial fibrillation or cardiovascular disease
Chronic –
The organs of the gastrointestinal system are responsible for the digestion of food. Therefore, decreased blood supply to these organs cause symptoms related to eating or after-meal digestion, including –
- Abdominal pain after meals
- Weight loss
- Fear of eating or change in eating habits due to post-meal pain
- Nausea and/or vomiting
- Constipation or diarrhea
- History of cardiovascular disease (such as peripheral arterial disease, stroke, coronary artery disease or heart attack)
Complications
- Death of intestinal tissue – If blood flow to the intestine is completely and suddenly blocked, intestinal tissue can die (gangrene).
- Perforation – A hole through the wall of the intestines can develop. This results in the contents of the intestine leaking into the abdominal cavity, causing a serious infection (peritonitis).
- Scarring or narrowing of the colon – Sometimes the intestines can recover from ischemia, but as part of the healing process the body forms scar tissue that narrows or blocks the intestines.
- Death
Treatment
Surgery – Emergency surgery may be performed to remove the blood clot (embolectomy) or bypass the blocked vessel and restore blood flow to the intestines. The surgeon may use autologous bypass grafts (patient’s own blood vessels) or artificial grafts. In some cases, the surgeon may need to remove a portion of the intestine if tissue death has occurred.
In Chronic situation surgery may be performed to remove plaque (endarterectomy), bypass the blocked vessel to restore blood flow to the intestines, or remove or repair an aneurysm. The surgeon may use autologous bypass grafts (patient’s own blood vessels) or artificial grafts during the bypass procedure.
Medication – Anticoagulant medications, such as Coumadin (warfarin – a blood-thinner), to reduce the risk of blood clots.
Angioplasty and stenting – A balloon catheter is used to attempt to open the artery and a small stent is placed inside the artery to keep it open.
Alternative Treatment
Quercetin is a naturally occurring flavonoid with antioxidant, anti-inflammatory, and anticancer properties. Quercetin has been shown to enhance intestinal barrier functions in human intestinal cells.88 Mast cells play an important role in the pathogenesis of intestinal mucosal inflammation and increased IP. Quercetin helps to control intestinal inflammation by inhibiting histamine release from human intestinal mast cells.
Ginkgo biloba extract (GBE) has antioxidant and free radical–scavenging properties with cytoprotective effects on cells of the gastrointestinal mucosa. Oral supplementation with GBE has been shown to reduce macroscopic and histological damage to the colonic mucosa in vivo and to significantly decrease pro-inflammatory cytokines in experimentally induced ulcerative colitis.
Vitamins C and E plays an essential roles in protecting intestinal mucosal cells from oxidative damage and free-radical pathology.
N-acetyl-L-cysteine (NAC) is an antioxidant, detoxifier, and precursor for glutathione synthesis on oral administration in humans. NAC and glutathione quench free radicals that can contribute to oxidative damage of the intestinal mucosa.
L-glutamine is an important energy source for cells of the intestinal mucosa and has been shown to be conditionally essential for normal mucosal structure and function. Glutamine appears to be required for normal production of secretory immunoglobulin A (IgA) in the intestines.
N-acetyl-D-glucosamine (NAG) is a naturally occurring aminoglycan found in large concentrations in intestinal mucus, secretory IgA, and other immunoglobulins. Intestinal mucus plays a critical role in protecting the host by providing a mechanical and immunological barrier against toxins, antigens, and bacteria in the gut lumen.
Pancreatic enzymes have optimal activity in the neutral to alkaline pH range and are unstable in acidic conditions.
Probiotics Intestinal microflora have been described as a postnatally acquired organ comprised of a large diversity of bacteria that perform a range of important functions for the host. Probiotics are orally administered microorganisms that help to maintain or restore beneficial intestinal microflora and prevent or treat gastrointestinal disorders and related systemic conditions.
Psyllium seed and flaxseed fiber each demonstrate benefits of both soluble and insoluble dietary fiber in humans. It helps in intestinal health.
Boswellia is an excellent herb helping to reduce immune cells that promote inflammation while increasing the number of immune cells that inhibit inflammation.
Chamomile is a popular herb best known for it’s calming properties. It helps to calm muscle spasm in stomach and has anti-inflammatory properties helping to reduce symptoms of ischemia.
Reference –
http://www.drugs.com/mcd/intestinal-ischemia
http://radiopaedia.org/articles/intestinal-ischaemia
http://www.webmd.com/digestive-disorders/intestinal_ischemia_infarction
https://www.nlm.nih.gov/medlineplus/ency/article/001151.htm
http://emedicine.medscape.com/article/189146-overview
http://avsurgery.com/mesenteric-ischemia-intestinal-angina/