Abdominal Aortic Aneurysm (AAA): Bifurcated Graft Interposition

Step 1: Exposition of the aneurysm

1. Abdominal wall retractor and transperitoneal exposition of the AAA, including definition of anatomical landmarks
2. Placement of silicone tube around the proximal neck
3. After preparing the iliac bifurcation, a distal clamp (preferably cobra clamp with its special branches keeping fat tissue away) is positioned including both the hypogastric and the external iliac arteries
4. Clamping of the ipsilateral common iliac artery 2 cm proximal to the iliac bifurcation (especially in high risk cardiac patients it is of advantage to keep the aortic clamping time short)

Step 2: First iliac anastomosis

1. Place the bifurcation of the graft 2 cm above the original bifurcation and shorten the ipsilateral limb of the graft
2. Transsect the common iliac artery above the iliac bifurcation (cave common iliac vein and ureter)
3. Suture material: 4x0 double needle polypropylene suture starting again at 3 o‘clock and make your knots after pulling the suture tight
4. Next step is the dissection of the left iliac bifurcation. Move the sigmoid colon to the right and incise the retroperitoneum laterally to the sigmoid colon

Step 3: Proximal (aortic) anastomosis

1. Clamping of left common iliac artery with a straight clamp (simple sagital cross-clamping usually without dissecting the artery). If available a 10 cc venous balloon catheter instead of a clamp is preferable to block the common iliac artery
2. Infrarenal cross-clamping using Glover clamp (rear branch of the clamp is conducted behind the aortic wall by means of a silastic tube)
3. Anterolateral longitudinal incision of the aneurysm wall for 2 cm on the right side of the inferior mesenteric artery and perforation of the thrombus with the suction device
4. Extend the incision towards the proximal neck and distally into the right common iliac artery. The proximal incision stops 1 cm distally to the proximal clamp. Proximally the incision is extended horizontally until 3 o’clock and 9 o’clock, respectively, like wings of a double door
5. Suture ligation of lumbar arteries
6. Control of inferior mesenteric artery back bleeding
7. The prosthetic graft main body should measure at least 6-8 cm
8. Anastomotic technique as described under ‘tube graft interposition’
9. After having finished the proximal anastomosis, flush the graft from distally and proximally and remove the aortic and right iliac clamp

Step 4: Second iliac anastomosis

1. Divide the left CIA 2 cm above the iliac bifurcation, pull the contralateral limb through the genuine left CIA and perform the end-to-end anastomosis (parachute technique)

Control of educational objectives (tutor and trainee)

• Leak tightness of proximal and distal anastomosis
• Sequence of stitches
• Transmural stitching ("big bites")
• Correctness of the inlay-technique
• Appropriate length of graft
• Appropriate clamping
• Applying additional (extra) stitches (U-stitch, Borst stitch)