Blockage or narrowing of one of the big arteries in the abdomen that branch off the aorta is known as abdominal aortic branch occlusion. Atherosclerosis, abnormal muscle growth in the artery’s wall (fibromuscular dysplasia), blood clots, and other conditions can cause aorta branches to become blocked (occluded).
- A blockage creates symptoms in the area served by the artery, such as discomfort, due to a lack of blood flow.
- The diagnosis is made using imaging studies.
- The removal of a blood clot, angioplasty, or surgical bypass grafting is all options for treatment.
The aorta is the body’s biggest artery. It takes oxygen-rich blood from the heart and distributes it to the rest of the body via smaller arteries that branch off. The section of the aorta that goes through the abdominal cavity is known as the abdominal aorta. The arteries that give blood to the organs are important branches of the abdominal aorta.
- Small intestine (celiac artery and superior and inferior mesenteric arteries)
- Kidneys are organs that filter waste from the body (renal arteries)
- Legs are the longest part of the body (iliac arteries)
- The arteries that branch off the aorta might become blocked suddenly or gradually.
A blood clot that has formed in the artery or moved into it from elsewhere (embolism), or the layers of the artery suddenly separating, can cause sudden obstruction (acute occlusion) of branches of the abdominal aorta (dissection).
Hardening of the arteries (atherosclerosis), in which deposits of cholesterol and other fatty materials (atheromas or atherosclerotic plaques) develop in the walls of arteries, abnormal muscle growth in the artery’s wall (fibromuscular dysplasia), or compression of the artery by a growing abdominal tumor can all cause gradual blockage of branches of the abdominal aorta.
A similar blockage can occur in the legs or, less occasionally, the arms.
Abdominal Aortic Branch Occlusion Symptoms
A sudden blockage interrupts blood flow, resulting in extreme agony. Depending on whatever artery is blocked, pain may occur in the abdomen, back, or legs. Unless blood flow is restored, organ failure and tissue death (necrosis) ensue within hours.
The symptoms of a slowly forming blockage differ depending on which artery is affected and how severe the obstruction is.
Aorta inferior and iliac arteries
When the lower aorta is suddenly blocked where it separates into the common iliac arteries, both legs become uncomfortable, pallid, and chilly. The legs may go numb because there is no pulse. An iliac artery obstruction causes symptoms in only one leg.
Gradual constriction of the lower aorta or both common iliac arteries can produce cramping and soreness in the buttocks and thighs of both legs (intermittent claudication). The legs may also feel cold or appear pale, even though they appear to be normal. Erectile dysfunction can also be caused by a chronic blockage. Leriche syndrome is a term used to describe the conjunction of claudication and erectile dysfunction.
Arteries of the kidneys
A total blockage of one of the renal arteries, which supplies the kidneys, might result in sharp pain in the side and bloody urine.
The constriction of one or both renal arteries gradually and moderately may not create symptoms or compromise kidney function. More severe constriction of one or both renal arteries might cause kidney failure or excessive blood pressure in rare cases (a disorder called renovascular hypertension). Renovascular hypertension affects less than 5% of patients with high blood pressure. Renovascular hypertension, on the other hand, might be difficult to manage.
The superior mesenteric artery is a blood vessel that runs through the stomach.
A medical emergency is a sudden, full blockage of the superior mesenteric artery, which produces severe abdominal discomfort, nausea, and vomiting. Most people who have a blockage vomit at first and feel compelled to produce a bowel movement. Because the superior mesenteric artery serves a major portion of the intestine, they may become extremely unwell and experience considerable abdominal pain. When a doctor touches on the abdomen, it may feel uncomfortable, but the severe abdominal pain is usually more evident than the diffuse and vague discomfort.
Because the bowel requires more blood during digestion, gradual narrowing of the superior mesenteric artery causes pain 30 to 60 minutes after each meal. The pain is constant and strong, and it is frequently located around the navel. Because this pain makes patients scared to eat, they may lose a lot of weight. Nutrients may be inadequately absorbed into the bloodstream as a result of the diminished blood supply to the intestine, contributing to weight loss. Nausea, vomiting, constipation, and diarrhea are common symptoms of those who have pain after eating.
Hepatic and splenic arteries
Blockage of the hepatic or splenic arteries, which supply the liver and spleen, is usually less hazardous than blockage of the major arteries that supply the gut. Parts of the liver or spleen, however, may be damaged. Abdominal pain, fevers and chills, nausea, vomiting, and skin yellowing are all possible symptoms of hepatic artery blockage (jaundice).
Diagnosis of Abdominal Aortic Branch Occlusion
Doctors can typically suspect the diagnosis based on the patient’s symptoms and physical examination findings. To confirm the diagnosis, imaging techniques including duplex ultrasonography, computed tomography (CT) angiography, magnetic resonance angiography, or conventional angiography are utilized.
Angiography, an invasive procedure in which a flexible plastic catheter is placed into one of the main arteries in the upper thigh, is usually reserved for situations where surgery or angioplasty (opening a blockage by inflating a small balloon within the artery) is not an option. Its objective in such circumstances is to give clinicians clear views of the damaged arteries prior to surgery or angioplasty. Angiography is only required in a few cases to determine whether surgery or angioplasty is possible. A contrast chemical that may be seen on x-rays is injected into an artery via a flexible plastic catheter during angiography. When x-rays are taken, the contrast agent creates an outline of the inside of the artery. As a result, angiography can reveal the exact diameter of an artery and is more accurate than Doppler ultrasonography in finding some blockages.
Most medical institutes now do angiography utilizing a less invasive technique like computed tomography (CT angiography) or magnetic resonance imaging (MRI) (called magnetic resonance angiography, or MRA). Rather of inserting a flexible catheter into a major artery, these tests employ a conventional intravenous catheter in the arm to deliver modest volumes of a radiographic contrast agent into the bloodstream through a vein.
Treatment for Aortic Branch Occlusion in the Abdomen
Angioplasty (blood clot removal) or angioplasty (blood flow restoration)
Acute occlusion is a surgical emergency that requires the removal of the blood clot (embolectomy), angioplasty, or another surgery to restore blood flow to the affected area (such as administering medicines to break up the clot or performing emergency surgical bypass).
Aorta inferior and iliac arteries
Surgery is performed right away if the lower aorta and common iliac arteries become completely blocked. Embolectomy is performed by inserting a catheter into an artery and using it to dislodge or suck out the clot, or by making an incision in the artery and manually removing the clot during open surgery.
Arteries of the kidneys
For sudden, full blockage of a renal artery, angioplasty with blood clot removal or surgery is used. The surgery can help restore blood flow and renal function if done quickly.
Angioplasty involves inserting a catheter with a balloon at its tip into the narrowed part of the artery, inflating the balloon to clear the blockage, and sometimes placing an expandable metal mesh tube (stent) at the blockage site to keep the blood channel open. Drug-eluting stents are stents that include medications that are gently released and prevent the blockage from regrowing. Surgery or angioplasty may be required if a prolonged blockage causes symptoms. Antiplatelet medications may be of assistance.
As long as blood pressure is under control and blood tests show that the kidneys are functioning normally, no specific therapy is required for gradual, moderate occlusion of a renal artery. Antihypertensive medications are used if renovascular hypertension develops. At least three antihypertensives are frequently required. Inhibitors of the angiotensin-converting enzyme (ACE) are particularly beneficial. When using ACE inhibitors, it’s important to keep an eye on your kidney function. Doctors may perform angioplasty or bypass surgery to restore blood flow to the kidney if high blood pressure persists and is severe, or if kidney function is decreasing.
Superior mesenteric artery
Only rapid angioplasty with stent placement, surgery, or pharmacological treatment can restore the blood supply quickly enough to save the person’s life when the superior mesenteric artery is abruptly and fully blocked. Doctors frequently take patients directly to surgery rather than performing diagnostic testing to save time. Doctors may remove or bypass the obstruction during surgery, or they may remove the afflicted section of the intestine.
When angiography is used to diagnose a blockage, drugs that dissolve clots or expand (dilate) the arteries may be used during the process. These medications are injected directly into the artery and have the potential to clear the blockage. This method may eliminate the need for surgery. The speed with which the blood flow is restored determines whether a person survives and whether the gut can be spared.
If the superior mesenteric artery has constricted over time, nitroglycerin may help reduce stomach pain, but angioplasty or surgery to expand the artery is still required.
Hepatic and splenic arteries
To clear a blockage in the hepatic or splenic arteries, surgery is required.