Mesenteric arteries carry oxygen rich blood to the gastrointestinal tract. The stomach, small and large intestines, colon, and rectum are dependent on this blood supply to carry out digestive processes. Obstruction of blood flow can result in ischemia (lack of blood supply) of the intestines. The inner wall of a normal artery is smooth and blood flows through it without difficulty. When atherosclerosis (also known as hardening of the arteries) develops it is due to the lining of the artery becoming rough and thickened. The thickening of the arterial walls is often caused by deposits of fatty materials, such as cholesterol, clogging the arteries. Changes that occur in the blood vessels do not occur overnight but develop over many years.
There are two categories of mesenteric ischemia: Acute Intestinal Ischemia and Chronic Intestinal Ischemia. Acute Intestinal Ischemia is recognized and diagnosed by symptoms. It can present with an acute (sudden) onset of sever abdominal pain, vomiting and diarrhea. It can occur gradually, with pain after eating, weight loss and change in bowel habits. Chronic Intestinal Ischemia is caused by atherosclerosis, or hardening of the arteries. This causes plaque to build up on the inner layer of the artery. Atherosclerosis usually progresses slowly in the mesenteric vessels. The most common symptom is abdominal pain after eating increasing in severity over several weeks or months. The type of pain varies with each patient, from a continuous, dull ache to colicky pain. Less food is ingested, leading to weight loss.
Some symptoms that may occur are:
- Abdominal Pain (especially after eating)
- Weight Loss
- Change in Bowel Habits
RISK FACTORS FOR ARTERIAL DISEASE OR ATHEROSCLEROSIS
Studies have been done on people with atherosclerosis. This is to help predict which people will be at a high risk of developing this disease. These people usually have one or more of the following risk factors:
- Hypertension (high blood pressure)
- High cholesterol
- Family history of atherosclerosis
It is important to try and eliminate or minimize the risk factors that you can control, such as smoking, obesity, diabetes, and your activity level.
Non Invasive Testing – Doppler
You may eat and drink before the exam and take your usual dose of medications unless instructed otherwise. This is an ultrasound stethoscope. The vascular technician will place a hand held transducer, or probe, on your skin with some gel to perform the test. This test takes about fifteen minutes to complete.
You should avoid eating or drinking four hours prior to your abdominal ultrasound. It is difficult for the technician to visualize the arteries if your abdomen is full.
Invasive Arterial Testing – Angiogram
Magnetic resonance Angiography (MRA)
This test uses a large scanner that is magnetic based to produce images based on water content. This is not a painful process. It requires approximately 45-60 minutes to complete the test. We need to know if you are claustrophobic (fearful of small places) or have metal clips, implants, or a pacemaker.
Remove any jewelry or watches before the test.
Invasive Arterial Testing
An angiogram is an x-ray of your arteries. This test is done to determine the exact location of disease within your arteries. It is performed by a team of physicians, physician assistants, nurse practitioners, nurses, and technicians. You will meet with someone before the test. They review the procedure, possible side effects and ask you to sign a consent form. Blood work is drawn before the test to determine the ability of your blood to clot and your kidney function.
You will be required not to eat solid foods eight hours before, and will need to stop liquids three hours before the angiogram. You will receive specific instructions regarding your medications, insulin and blood thinners from your doctor or nurse before the test.
You will not be able to drive for one day following the procedure. Therefore, you will need to make arrangements for someone to drive you home.
If you are a diabetic, please check your fingerstick the morning of the your procedure.
For the test, an intravenous catheter is inserted into a vein in your arm and you may be given intravenous fluids and/or medications to help you relax. The femoral artery in your groin is most often used to insert a catheter in which to inject dye; however the artery in your inner elbow or armpit may also be used. The area is first shaven and then numbed with a local anesthetic.
A catheter is inserted into the artery and dye is injected and then x-rays are taken. You will feel a warm sensation in your body as the dye is injected. When the catheter is removed, the physician will apply pressure to the insertion site for approximately fifteen minutes. The procedure takes one to one and a half hours to complete. After the procedure you will need to be on bed rest with the affected leg or arm straight for four to six hours. This is to prevent any bleeding at the puncture site.
The dye acts like a diuretic, or water pill, so you may need to urinate frequently. You should drink a lot of fluids to help flush the dye from your kidneys. Notify nurses or doctor if you have any pain, numbness, or tingling during or after the procedure.
Some of our patients will need to take a medication called Mucomyst the day before the procedure. Is is a small amount of a clear liquid with a bitter taste that can be taken in a small amount of fruit juice.
ONLY if we have indicated that you will need it, it will be taken as follows:
- One dose at 3pm the day before procedure
- One dose at 7pm the evening before procedure
- One dose in am of procedure just prior to leaving for your test
Please let your doctor or nurse know prior to the test if your are allergic to contrast dye or shell fish. Then we will take appropriate precautions.
You will be admitted on the Vascular Surgery service under the care of the Vascular Surgeons. Your referring physician and any other medical specialists will be notified of your admission and surgery date.
If an angiogram is ordered on the day of admission, you should report to the specified area at the instructed time. Otherwise, you will receive a phone call from the Admitting Office with instructions for your arrival. If you do not receive a phone call by noon, please contact our office.
If you are to be admitted the day of surgery you will need to have pre-admission testing prior to your scheduled surgery. At pre-admission testing you will meet with an anesthesiologist, and nurse. You may have blood work, a urine test, EKG, and a chest x-ray. They will review pre-operative instructions including fasting and medications to take the morning of surgery.
The whole procedure takes approximately two to three hours. If you need to have any other testing we will try to schedule it the same day. If you are to be admitted the day before your surgery the above tests will be performed when you are admitted.
For same day surgery the hospital will notify you the day before your surgery after 2:00pm to tell you what time to report to the hospital. If your surgery is on a Monday you will be notified the Friday before your surgery.
TREATMENT FOR MESENTERIC ATERIAL ISCHEMIA
Eliminate or minimize your risk factors for atherosclerosis; don’t smoke, see a doctor to control your blood pressure or diabetes, eat a low fat and low cholesterol diet, lose weight if overweight, and perform regular exercise.
Angioplasty and Stenting
This procedure may be used for short areas of blood vessels narrowing. This would be done at the same time as your angiogram if the doctor felt that is would be successful. A small catheter with a balloon is inflated and pushes the plaque against the inner wall of the artery making room for more blood flow. Then a stent is left in place to keep the artery dilated. The balloon is deflated and the catheter is removed. Dye is then injected and x-ray pictures are taken to make sure the artery has opened adequately. You will stay overnight in the hospital.
An antiplatelet agent is usually given prior to the procedure and for some time after 1-3 months or longer. These are used to reduce the risk of platelet aggregation (clumping) and thrombus (clot) formation. Plavix and aspirin are common antiplatelet agents that are generally prescribed before and/or after your stenting.
Depending on the exact location and extent of your blockage the doctor will determine what surgery will be performed. Your doctor will have a general idea of what surgery needs to be performed after talking to you about your symptoms, and reviewing your chart. The surgery involves using a plastic tube to bypass the blockage. It usually takes about 3 hours and you can expect to be in the hospital for 5-7 days.