Endovascular Repair of
Abdominal Aortic Aneurysm
Abdominal Aortic Aneurysms are a significant and relatively common vascular
problem. The incidence of aneurysms will dramatically increase as
the population ages. 1.5 million Americans have an abdominal aortic
aneurysm with 200,000 new cases diagnosed each year. The remaining
patients are followed expectantly. The prevalence among males 65-74
years old is 3-6% and may be as high as 12% in males with
hypertension.
Diagnosis
and treatment of this disease is very important. Ruptured abdominal
aortic aneurysms result in 15,000 deaths per year in the U.S. (13th
leading cause of death in U.S.) Emergency repair has high perioperative
mortality (40-50%) as compared to elective repair (1-5%).
Open surgical repair is the standard treatment for Abdominal Aortic
Aneurysm; however, endografts and endovascular stent grafts have
recently been developed and allow less invasive treatment of some
aneurysms.
Open repair requires a large abdominal incision as well as clamping of
the aorta above and below the aneurysm. The aorta is then opened and a
graft is sewn in. There is also extensive bowel manipulation involved.
This surgery has an 18% complication rate with prolonged hospitalization
and associated morbidity. Virtually all patients require an NG tube
secondary to ileus from bowel manipulation. Moreover, patients also
spend a significant length of time in the intensive care unit.
In contrast, placement of an endograft avoids an open abdominal incision
with only bilateral groin cut-downs necessary. Moreover, there is no
bowel manipulation and overall complications are cut in half. This
translates into decreased hospital stay (9.3 days for open repair vs.
3.4 days for endograft) and faster time to ambulation (3.6 days for open
repair vs. 1.4 for endograft).
Unfortunately, only 15-30% of aneurysm patients are candidates for endograft placement.
Anatomic limitations for endograft placement include aneurysms that
involve the renal arteries, aneurysms with extremely short necks, iliac
vessels that are less than 7 mm or greater than 13.4 mm in diameter,
densely calcified vessels, very small femoral vessels, and severe
angulation of the aneurysm neck. These limitations make preoperative
measurement and evaluation of the aneurysm very important; consequently,
both conventional angiography and CT angiography need to be performed.
These imaging procedures can be performed on an out-patient basis.
In summary, endograft placement allows 15-30% of abdominal aortic
aneurysms to be treated by less invasive means with a decrease in
morbidity when compared to open surgical repair.
This procedure is performed by SDI Radiologists at St. Joseph's
Hospital.
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