Infrarenal abdominal aortic aneurysm occurs just below the kidney.Abdominal Aortic Aneurysm is an illness that occurs when the walls (lining) of the aorta (the largest blood vessel that extents until the abdomen and is located in the left ventricle of the heart) begins to balloon. The ballooning (swelling or expansion) process is called dilatation. When the blood vessel grows out of proportion, it ruptures and leads to internal bleeding. Aneurysm occurring above the kidney is called suprarenal ‘AAA’. If it is located at the same level or on top of the kidney, it is called pararenal ‘AAA’ and if it occurs just below the kidney it is called infrarenal ‘AAA’.
Here we will look at infrarenal abdominal aortic aneurysm in detail.
Shape of infrarenal ‘AAA’
‘AAA’ has asymptomatic symptoms hence common symptoms like pain in abdomen and swelling in the blood vessel could be mistaken as symptoms of some other aliment. The correct way to decipher if the dilatation is related to ‘AAA’ is through its shape. The outer area of the blood vessel is called adventitia; it is a thin connective tissue on the surface of the blood vessel. If an aneurysm is present only in the outer layer of the blood vessel (walls) it is not an abdominal aortic aneurysm.
A correct ‘AAA’ is made of three layer called the adventitia that is an outer connecting tissue, the media that is muscular elastic fibers and intima that is made up of endothelial cells. Actual infrarenal abdominal aortic aneurysm is located inside the endothelium. The shape of the aneurysm is saccular (bag like formation that contains liquid) or fusiform (spindle or rounded shape that tapers from center to each end). The saccular aneurysm balloons only on one side of the aorta whereas fusiform shaped aneurysm covers entire area that is all sides of the aorta.
Fusiform infrarenal ‘AAA’
Most common form of infrarenal abdominal aortic aneurysm is fusiform aneurysm. In fusiform infrarenal ‘AAA’, all three layers of the blood vessel are involved. Fusiform aneurysm can expand up to 20 cm in diameter and spread to the iliac arteries as well. This condition exerts pressure on the adjoining tissues that causes pain in the chest, abdomen and legs. Fusiform infrarenal ‘AAA’ affects the ascending aorta and in some cases the root and the arch of the aorta as well. It occurs just below the kidney situated slightly away towards the left subclavian artery. As the time passes by calcification takes place.
If a patient is detected with, infrarenal ‘AAA’, treatment can be done by regularly monitoring the growth of the aneurysm and by controlling smoking, blood sugar levels, exercising and keeping a check on diet. Medication can be given to avoid high blood pressure and hyperlipidemia. In severe cases, the aneurysm needs to be repaired through surgery.
Repairing infrarenal abdominal aortic aneurysm
There are two ways to repair infrarenal aneurysm. An open surgery or endovascular surgery.
Open surgery: A large opening is created in the abdomen so that the aneurysm is clearly visible. A graft that looks like a cylindrical tube is sewn from one end of the aorta to the other end covering the aneurysm.
Endovascular surgery: Endovascular surgery is less invasive compared to open surgery. An incision in the groin is made to insert a stent graft that is made of metal mesh and is cylindrical in shape. A femoral artery is slightly pulled out; the stent graft is inserted into the artery and made to travel up to the place of the aneurysm with help of appropriate medical equipment. The stent is used to keep the graft open and hold it tightly in place.
Infrarenal abdominal aortic aneurysm could be fatal condition as symptoms are asymptomatic and sudden onset of symptoms results in rupture of the blood vessel. Hence, if the aneurysm has grown over 5cm it is imperative to get a surgery done.