What is Abdominal Aortic Aneurysm?
An aortic aneurysm is a bulging or ballooning out of the main artery of the body called aorta. The abdominal aorta is the last and largest section of the aorta. It supplies blood to the lower regions of your body including the organs in the abdomen and pelvis. The abdominal aorta ends around the naval level where it splits into the two iliac arteries that carry blood to the legs. The aorta has thick walls so that it can withstand the high pressures of the blood being pumped from the heart. Over the time, the aorta weakens and may get swollen like a balloon. When this happens in the abdominal region, it is called abdominal aortic aneurysm. Most AAAs or abdominal aortic aneurysm affects the portion of the aorta just below the kidney arteries and above the iliac branches.
Symptoms and Diagnosis of Abdominal Aortic Aneurysm
An abdominal aortic aneurysm can be dangerous if it isn't spotted early on. It can get bigger over time and could burst causing life-threatening bleeding. Screenings are recommended for people who have a family history and in men who are aged 65 and over and have smoked. This is why men are invited for screening to check for an abdominal aortic aneurysm when they're 65.
Abdominal aortic aneurysm doesn't usually have specific symptoms and is often referred to as a silent killer as they cause no symptoms or problems prior to bursting. It is mostly diagnosed during imaging studies done to diagnose other conditions. Your surgeon may perform an abdominal aortic aneurysm repair if you have one or more of these conditions:
- The diameter of your aorta exceeds 2 inches.
- You have intense abdominal pain and/or back pain.
- An abnormally prominent abdominal pulsation.
- The purpose of the surgery is to prevent the aneurysm from rupturing or bursting.
To diagnose your abdominal aortic aneurysm, your doctor will review your medical and family history and perform physical examination. If your doctor suspects that you have AAA or abdominal aortic aneurysm, he will order specialized tests mentioned below-
- Abdominal Ultrasounds are most commonly used to diagnose abdominal aortic aneurysm.
- CAT scan with IV contrast is used typically to identify the shape and diameter of the aneurysm.
- MRI is performed to diagnose the size and location of the aneurysm.
The U.S. Preventive Services Task Force recommends that men aged 65 to 75 who have ever smoked should have a one-time screening for abdominal aortic aneurysms using abdominal ultrasound. Men aged 60 and older with a family history of abdominal aortic aneurysms should consider regular screening for the condition.
Treatment of Abdominal Aortic Aneurysm
Depending on the size of the aneurysm, your doctor will suggest you the treatment.
- For small abdominal aortic aneurysms (ranging about 3cm to 4.4 cm across) annual ultrasounds are recommended to check if it's growing bigger. You will be asked to follow a healthier lifestyle.
- For medium sized abdominal aortic aneurysms (about 4.5cm to 5.5cm), ultrasounds are recommended every 3 months to check if it's growing. You will be asked to follow a healthy lifestyle.
- For abdominal aortic aneurysms that are larger than 5.5cm or more, you will be recommended a surgery to stop it getting bigger.
Surgery for Abdominal Aortic Aneurysm
Before the procedure:
- IV line will be placed
- General anesthesia will be administered
- Breathing tube will be inserted
- Catheter placed in the bladder
The abdominal aortic aneurysm repair surgeries can be performed in one of the below mentioned ways:
Open Repair. The traditional operation involves cutting open your abdomen to replace the aneurysm with an artificial piece of artery (a graft). For this surgery, your doctor makes a large incision in the abdomen to expose the aorta. Once the abdomen has been opened, a graft can be used to repair the aneurysm. Open repair remains the standard procedure for an abdominal aortic aneurysm repair and this procedure takes about 4 to 6 hours.
Endovascular Aneurysm Repair (EVAR). This procedure is preferred in people who:
- Have a heart disease
- Are at a higher surgical risk due to age or other factors.
This is a minimally invasive procedure requiring only a small incision in the groin. The surgeon will insert special instruments through a catheter in an artery in the groin and thread them up to the aneurysm. At the aneurysm, your doctor will place the stent and graft to support the aneurysm. This surgery usually takes 2 to 3 hours.
Recovery and Aftercare Following Abdominal Aortic Aneurysm Repair
After the procedure breathing tube will be removed. You will be monitored in the recovery area. IV line will be established. A stomach tube will be inserted. An open surgery requires about 5 to 10 days of hospital stay whereas an endovascular procedure requires 2 to 3 days hospital stay. You will be fully recovered by the end of about 6 to 12 weeks for any kind of activities. The nurses and doctors will try and keep you free of pain by giving painkillers by injection, via the epidural tube in your back, or by a machine that you are able to control yourself by pressing a button. Injection for (deep vein thrombosis) and PE (pulmonary embolus) prophylaxis will be given to you until you are discharged and fully mobile. You can start your exercise, driving, bathing, work etc after a certain amount of time after your surgeon clears you for these.
Complications of Abdominal Aortic Aneurysm Repair Surgery
All surgeries carry risks related to anesthesia, bleeding, infection and stress on the heart resulting in irregular heart rhythm and heart attack. Additional common problem related to open surgery are development of a hernia or bulge; this occurs in about 10 to 20% of the patients. Sometimes there is alteration in sexual function in men. Less common complications are loss of circulation to the legs or large intestine in immediate postoperative period.
Survival Rate Following Abdominal Aortic Aneurysm Repair Surgery
Survival after repair of ruptured abdominal aortic aneurysm depends on a number of patient factors, such as age and comorbid conditions and the patient's management within the healthcare system, including accuracy of diagnosis, time from symptoms to surgery, and skill of the surgical team. The age of the patient cannot be changed, and comorbid conditions can be optimized but not eliminated. Studies show that perioperative mortality rate is less in EVAR procedure as compared to open procedure. A study found improvement in short term survival rates of patients who underwent surgery to repair a ruptured abdominal aortic aneurysm. The relative survival rate held at about 87 percent. Patients undergoing elective repair of intact aneurysm face low risk and can expect normal longevity after surgery. The fact that operative treatment is offered to older patients, with more frequent cardiovascular disease, could have resulted in inferior long-term outcomes. Accurately selected elderly patients can have excellent long term survival after surgery.