Small Bowel Ischemia - Causes, Symptoms, Diagnosis, and Treatment

Introduction:

Small bowel ischemia is a group of conditions that reduce blood flow to the small intestine (duodenum, jejunum, or ileum). It occurs when a narrowing or block occurs in one or more arteries supplying the small intestine. The three major abdominal blood vessels that get blocked include the celiac artery, superior mesenteric artery, and inferior mesenteric artery. Decreased blood flow can sometimes permanently damage the small intestine. Small bowel ischemia is also known as mesenteric ischemia.

What Are the Causes of Small Bowel Ischemia?

Small bowel ischemia can be acute or chronic. Both acute and chronic small bowel ischemia is due to a decrease in blood flow to the small intestine. Acute mesenteric ischemia is mostly due to blood clots, and chronic mesenteric ischemia is due to atherosclerosis.

The possible causes of small bowel ischemia include:

• Blood Clots: These can partially or completely block arteries that supply blood to the intestine.

• Atherosclerosis: Atherosclerosis refers to a condition in which cholesterol clogs up the arteries leading to reduced blood flow.

• Hernia: Part of the intestine pushes through the abdominal muscle's weak area, resulting in reduced blood supply.

• Blood Pressure: Low pressure due to trauma or heart failure can reduce blood flow to the intestines.

What Are the Major Risk Factors for Small Bowel Ischemia?

The factors which increase the risk of small bowel ischemia include

• Age: The condition occurs more frequently over the age of 50.

• Abnormal Blood Pressure: Blood pressure that is too high or low.

• Smoking: Smoking can increase the risk of ischemia.

• Clotting Abnormalities: Blood clotting disorders like sickle cell anemia can increase the risk of ischemia.

• Medical Conditions: Conditions such as high blood pressure, high cholesterol, diabetes, heart failure, abnormal heartbeat, and stroke can increase the risk of ischemia.

• Medications: Medications for migraines, allergies, and birth control pills can cause a reduction in blood flow.

• Illicit Drugs: People who use Cocaine and Methamphetamine are at higher risk of developing ischemia.

What Are the Signs and Symptoms of Small Bowel Ischemia?

Symptoms vary from mild to severe, depending on the cause. The signs and symptoms of small bowel ischemia include:

• Sudden severe abdominal pain in acute ischemia.

• Abdominal pain gradually worsens and becomes more frequent and severe over weeks or months.

• Abdominal bloating.

• Fever

• Nausea.

• Vomiting.

• Blood in stool.

• The Urge to have bowel movements or sudden forceful bowel movements.

• Diarrhea.

• Weight loss.

• Unwillingness to eat.

What Is the Diagnosis of Small Bowel Ischemia?

• Physical Exam: The doctor will ask about the symptoms and risk factors and do a physical examination. A physical examination is done to check for tenderness or pain in the abdomen.

• Blood Tests: A blood test reveals a high white blood cell count as a result of infection.

• Stool Test: Stool samples are collected and checked for bloody stool and infection.

• Computed Tomography (CT) Scan: This imaging test uses X-rays to create cross-sectional images of the small intestine, abdomen, pelvis, and blood vessels.

• Magnetic Resonance Imaging (MRI): This imaging technique uses a magnetic field and radio waves to create more clear images of the intestines and abdominal organs.

• Angiogram: This is done only in severe cases. The doctor inserts a long, thin tube into an artery in the groin and guides it into the aorta. A dye is injected, which flows through the blood vessels of the intestine, and the doctor takes x-rays of the blood flow.

• Doppler Ultrasound: It is a non-invasive test that requires sound waves to detect the blood flow and narrowing of arteries.

• Computed Tomography (CT) Angiogram: This test uses a CT scan, and a dye is injected into the blood vessels to look for blockages.

What Is the Treatment for Small Bowel Ischemia?

Treatment solely depends on the severity of the condition. The goal of the treatment is to restore the blood supply of the small intestine and to maintain the function of the digestive tract. The doctor may recommend the following:

• Antibiotics to treat the infection.

• Blood thinners to prevent blood clots.

• Medications to clear the blood clots.

• Angioplasty and stenting (a minimally invasive procedure in which the doctor opens the narrowed blood vessels and places a metal stent inside the artery or vein to keep it open).

• In severe cases, surgery is done. Surgery is used to diagnose and also treat at the same time. The surgery is done in two methods: the open method, in which the surgeon makes a large cut in the abdomen to repair the small intestine, or to remove the dead tissue and restore the proper blood flow in the intestine by connecting the healthier parts. In the laparoscopic method, the surgeon makes several small cuts in the abdomen through which surgical tools and a laparoscope is inserted to remove blockages in the blood vessels and restore the blood flow. This laparoscopic method is known to be a minimally invasive procedure as it causes less pain and quicker recovery.

• After the surgery, eating a low-fat diet and eating small frequent meals are recommended. Regular exercise and as well as management of underlying conditions like diabetes, blood pressure, and cholesterol are recommended.

What Are the Complications of Small Bowel Ischemia?

In severe cases, small bowel ischemia can lead to:

• Gangrene: Gangrene is tissue death due to reduced blood flow.

• Perforation: Perforation in the intestine leads to leakage of contents of the intestine into the abdominal cavity.

• Peritonitis: Perforation in the intestinal wall can lead to peritonitis, which is a serious infection, and inflammation of the abdominal lining

Conclusion:

Early diagnosis and treatment are important to restore digestive function. Small bowel ischemia requires proper medical care to avoid the death of the intestinal tissue. In most cases, the condition is treated with surgery.