A mesenteric angiogram (MA) is a specialized X-ray imaging test that provides detailed pictures of the blood vessels supplying the intestines and abdominal organs. This procedure is a type of angiography, which uses a contrast medium, often called “dye,” to make the arteries visible on X-ray images. The primary focus is the mesenteric arteries, which carry oxygenated blood to the digestive tract. By visualizing these arteries, physicians can identify problems like blockages, narrowing, or active bleeding not easily detectable with standard imaging methods.
Primary Reasons for the Examination
The mesenteric angiogram is typically reserved for situations where less invasive tests have failed to diagnose a serious vascular issue within the digestive system. One frequent reason for this examination is to locate the source of acute or chronic gastrointestinal (GI) bleeding. If bleeding is rapid or severe, the contrast medium injected during the angiogram can be seen actively leaking out of the vessel, pinpointing the exact site of hemorrhage.
The test is also used to investigate mesenteric ischemia, a condition resulting from reduced blood flow to the intestines. This diminished circulation is often caused by narrowing or blockage in the mesenteric arteries, usually due to plaque buildup. This blockage leads to severe abdominal pain, particularly after eating, a condition sometimes referred to as “bowel angina.” Identifying these strictures helps determine if treatment can restore proper blood supply to the bowel.
Step-by-Step Guide to the Procedure
The mesenteric angiogram is performed in a specialized suite, usually by a radiologist. Before the procedure, the patient is positioned on an X-ray table, and monitoring devices are attached to track blood pressure, heart rate, and breathing. Conscious sedation may be administered to help the patient relax, though the access area is numbed with a local anesthetic.
The most common access point is the femoral artery, located in the groin. After the skin is cleaned, a small needle is inserted into the artery, through which a thin, flexible catheter is introduced. Using a continuous X-ray technique called fluoroscopy, the physician guides the catheter up the aorta until its tip is positioned within one of the mesenteric arteries.
Once the catheter is in place, the contrast medium is rapidly injected. This allows the arteries to become visible on the live X-ray screen, and images are captured to assess blood flow. Patients commonly report a temporary warm or flushing sensation when the contrast is injected. If a problem is identified, the procedure can immediately become therapeutic, such as performing embolization to block a bleeding vessel or inserting a stent to open a blocked artery.
Patient Preparation and Recovery
Patients are typically instructed to fast for six to eight hours before the test, meaning they cannot eat or drink anything, though small sips of water may be allowed with necessary medications. Blood tests are required beforehand to check kidney function, which is important for processing the contrast dye.
It is important to discuss all current medications with the medical team, especially blood thinners, which may need to be temporarily stopped to reduce the risk of bleeding. For diabetic patients taking Metformin, the drug may need to be held for about 48 hours after contrast injection to prevent complications. After the catheter is removed, firm pressure is applied to the groin site for up to 45 minutes to stop any bleeding.
The recovery phase requires the patient to remain lying flat for several hours, usually between four and six hours, to prevent bleeding or bruising at the artery access site. Nurses closely monitor the puncture site, vital signs, and circulation in the leg during this time. Patients are encouraged to drink plenty of fluids after the procedure to help flush the contrast material from their body.
Identifying Potential Risks
While the mesenteric angiogram is generally considered a safe procedure, patients should be aware of a few potential complications. Risks at the groin access site include bruising, pain, and the formation of a hematoma (a collection of blood under the skin). Less common risks include excessive bleeding or the formation of a blood clot that could reduce blood flow to the leg.
The use of contrast dye carries risks, including the possibility of an allergic reaction ranging from mild itching to a severe response. The contrast medium can also temporarily affect kidney function, which is a concern for patients with impaired kidney health. A rare but serious risk involves the catheter damaging the artery wall or dislodging plaque, which could block a vessel and lead to tissue damage.