General Principles

During the replacement of an infrarenal abdominal aortic aneurysm, the proximal anastomosis between the graft and the neck of the aneurysm is constructed in an end-to-end fashion. The basic techniques for preparing the neck of the aneurysm for the creation of the proximal anastomosis are illustrated in section “General Principles.” The aneurysm wall is incised longitudinally on its anterior aspect keeping to the right of the origin of the inferior mesenteric artery. The incision in the aorta is carried to the level of the neck of the aneurysm.

Intact Posterior Wall

The incision is then teed off on each side of the neck, leaving the posterior wall intact. The needle will penetrate the aorta approximately 1 cm proximal to the aneurysm neck (Fig. 14.1b) and will exit the posterior aortic wall 1.5–2 cm distal to the aneurysm neck (Fig. 14.1b). When tension is applied to the suture line, the layers of the aorta just proximal and distal to the aneurysm neck will be pulled together, resulting in a “double-layer” bite (Fig. 14.1c). The theoretical advantage of the “double-layer” bite is that the two layers will buttress each other, resulting in a stronger and more hemostatic bite.

The placement of the bites can be technically demanding when the posterior aortic wall is left intact. Occasionally, when the needle is introduced through the posterior aortic wall, its tip, as it exits distally, may not be easily visualized. The temptation to be avoided in such situations is to place a shallower bite. Shallow bites placed in the posterior aortic wall without incorporating the adventitia could tear through the aortic wall. The placement of deep bites and the retrieval of the needle from the aortic wall can be facilitated using a large needle, such as an MH needle (Ethicon).

The posterior suture line can be carried out using either an anchor or a parachute technique. The parachute technique can be started in the center of the posterior wall or at the beginning of the posterior wall, as shown in section “Parachute Technique.” When there is a mismatch between the diameter of the graft and the aortic neck, starting at the center could help in better judging the advancement between the bites.

The anchor technique is usually started in the center of the posterior suture line (section “Anchor Technique”). In general, the placement of the sutures could be facilitated if the surgeon performs his side of the suture line and the first assistant performs the other side. In another modification, the entire or part of the posterior suture line is constructed using an interrupted horizontal mattress suture technique. This technique could be useful when the aortic neck is very diseased. Additional sutures may be needed after the release of the clamps to secure hemostasis, especially with a heavily calcified wall.

Transected Posterior Wall

Another option is to transect the aortic wall completely (section “Transected Posterior Wall”). This facilitates the construction of the posterior part of the anastomosis. In this technique, after introducing the needle in the aortic wall, the needle tip can be easily visualized underneath the aortic stump. The transection of the aorta facilitates placing and retrieving the needle. The main disadvantage of this technique is the potential for venous injury during aortic transection. Injury to the vena cava or to a retroaortic renal vein or lumbar veins may result in undesirable bleeding. In addition, after transecting the aorta, the aortic wall may be found to be thinner than expected. In this situation, placement of pledget mattress sutures may be desirable to reinforce the aortic wall for a secure hemostatic anastomosis.

Transection of the aorta is routinely used in the technique of aneurysm exclusion with aortic bypass. It is also used when a transaortic endarterectomy of the renal arteries is contemplated in conjunction with an aortic reconstruction. In the management of aortoiliac occlusive disease, the proximal aorta may be transected when performing an aortobifemoral bypass routinely by some surgeons, especially when the aorta is heavily calcified or when dealing with a chronic aortic occlusion.

When the aortic wall is transected, the posterior suture line may be carried using an anchor or a parachute technique. The anchoring suture is usually started in the center of the posterior wall and may be a simple or a mattress suture. This technique could be ideal when the transected aorta is well exposed in a thin patient. If a parachute technique is used, the suture line may be started in the center of the posterior line or at one end of the posterior wall. Whenever the parachute technique is used, it is most important to check the tightness of the suture line with a nerve hook before tying the final knot.

In general, for right-handed surgeons, the construction of the posterior portion of the anastomosis is facilitated if performed from the opposite side of the table.

General Principles

General Principles