The aorta may be approached either transabdominally or through the retroperitoneal space. Juxtarenal and suprarenal aortic aneurysms are approached from the left retroperitoneal space. Self-retaining retractors are used. The bowel is kept warm and, if possible, is not exteriorized. The abdomen is explored for abnormalities (eg, gallstones or associated intestinal or pancreatic malignancy). Depending on the anatomy, the aorta can be reconstructed with a tube graft, an aortic iliac bifurcation graft, or an aortofemoral bypass.
For proximal infrarenal control, the first step is to identify the left renal vein. Occasionally (<5% of cases), patients may have a retroaortic vein. In this situation, care must be taken in placing the proximal clamp. Division of the left renal vein is usually required for clamping above the renal arteries.
Before aortic cross-clamping, the patient is heparinized (5000 U IV). If significant intraluminal debris, juxtarenal thrombus, or prior peripheral embolization is present, the distal arteries are clamped first, followed by aortic clamping.
With respect to pelvic outflow, the inferior mesenteric artery is sacrificed in most instances. Therefore, to prevent colon ischemia, every attempt must be made to restore perfusion from at least one hypogastric (internal iliac) artery. If the hypogastric arteries are sacrificed (eg, because of associated aneurysms), the inferior mesenteric artery should be reimplanted.
For supraceliac aortic control, the ligaments are first divided to the left lateral section of the liver, which is then retracted. The crura of the diaphragm are separated, and the aorta is bluntly dissected.
Supraceliac control is recommended for inflammatory aneurysms, along with minimal dissection of the duodenum and balloon occlusion of the iliac arteries. In patients with inflammatory aneurysms or large iliac artery aneurysms, the ureters should be identified; occasionally, ureteral stents are recommended in patients with inflammatory aneurysms.
The aorta is reconstructed from within by using a polytetrafluoroethylene (PTFE) or Dacron graft. The aneurysm sac is closed, and the graft is put into the duodenum to prevent erosion. Before restoration of lower-extremity blood flow, both forward flow (aortic) and backflow (iliac) are allowed to remove debris. The graft is also irrigated to flush out debris.
Before closure, the colon is inspected, and the femoral arteries are palpated. Before the patient leaves the operating room, the status of the lower-extremity circulation must be determined. If a clot was dislodged at the time of aortic clamping, it can be removed with a Fogarty embolectomy catheter. Heparin reversal usually is not required.
-
Radiograph shows calcification of abdominal aorta. Left wall is clearly depicted and appears aneurysmal; however, right wall overlies spine.
-
On radiography, lateral view clearly shows calcification of both walls of abdominal aortic aneurysm, allowing diagnosis to be made with certainty.
-
CT demonstrates abdominal aortic aneurysm (AAA). Aneurysm was noted during workup for back pain, and CT was ordered after AAA was identified on radiography. No evidence of rupture is seen.
-
Arteriography demonstrates infrarenal abdominal aortic aneurysm. This arteriogram was obtained in preparation for endovascular repair of aneurysm.
-
Lateral arteriogram demonstrates infrarenal abdominal aortic aneurysm. Demonstration of superior mesenteric artery, inferior mesenteric artery, and celiac artery on lateral arteriogram is important for complete evaluation of extent of aneurysm.
-
Arteriogram after successful endovascular repair of abdominal aortic aneurysm.
-
Ultrasonogram from patient with abdominal aortic aneurysm (AAA). This aneurysm was best visualized on transverse or axial image. Patient underwent conventional AAA repair.
-
MRI of 77-year-old man with leg pain believed to be secondary to degenerative disk disease. During evaluation, abdominal aortic aneurysm was discovered.
-
Age is risk factor for development of aneurysm.
-
Inflammation, thinning of media, and marked loss of elastin.
-
Pulsatile abdominal mass.
-
Aneurysm with retroperitoneal fibrosis and adhesion of duodenum.
-
Aortic endoprosthesis (Cook aortic and aortobi-iliac endograft).
-
Endoaneurysmorrhaphy
-
Endovascular grafts.
-
Atheroemboli from small abdominal aortic aneurysms produce livedo reticularis of feet (ie, blue toe syndrome).
-
Enhanced spiral CT scans with multiplanar reconstruction and CT angiogram.
-
Angiography is used to diagnose renal area. In this instance, endoleak represented continued pressurization of sac.
