Plate 156

The clamp is closed and the suture line completed and tied. The completed limb is occluded by finger control, and the aortic clamp is removed slowly. Blood flow is gradually reestablished to the limb to prevent hypotension (Figure 16). Close coordination between surgeon and anesthesiologist is required at this point so that the rate of opening the graft is compensated by fluids and blood administration with maintenance of stable blood pressure.

The other iliac anastomosis is carried out in similar fashion (Figure 17). The aneurysm sac, if adequate, is closed over the graft with a running suture (Figure 18). If at all possible, closure of the proximal aneurysmal sac should cover the aortic anastomosis so as to provide tissue between it and the duodenum. Alternatively, some surgeons tuck a segment of omentum in this region. The posterior peritoneum is reapproximated, with care taken not to injure the ureters.

In the presence of occlusive disease of the common iliac in addition to the aneurysm, the common iliac may be divided and oversewn with a continuous suture (Figure 19) on both sides following removal of the aneurysm. The graft is tailored to permit anastomosis of the aorta above the aneurysm with end-to-side anastomosis to the external iliacs beyond the points of stenosis (Figure 20). This bypass procedure makes extensive endarterectomy unnecessary and prevents sacrifice of the hypogastric arteries, which are important in maintaining colonic viability.

The small intestine is returned to the peritoneal cavity from the plastic bag, and the peritoneal cavity is cleared of blood clots and sponges. Before closure, particular attention is given to the adequacy of the blood supply to the sigmoid. Ordinarily, the blood supply is adequate after ligation of the inferior mesenteric artery. Evidence of bleeding from the prosthesis or at the site of anastomosis is thoroughly searched for before the closure is finally completed. The femoral vessels should be palpated from time to time to ensure that thrombosis has not occurred and that a good flow of blood is going through to the lower extremities. In case of doubt it may be necessary to reexplore one or both sides and remove any blood clots that are found. Routine abdominal closure is done.

Postoperative care usually is provided in an intensive care unit for the first 24 to 48 hours. In the postoperative period it is particularly important to ensure that there is a good blood supply to the lower extremities and a good hourly output of urine. Blood should be given until all major blood loss has been replaced, and the blood pressure is satisfactory. The use of a cell saver system during surgery should lessen this need for blood replacement. Intravenous fluids are administered slowly during the first 24 hours to ensure a steady output of urine from the indwelling catheter. The presence or absence of pulsation in the dorsalis pedis arteries should be recorded. Confirmation may be difficult at first, but the pulsations usually become more apparent later in the postoperative period. If pulsations are absent and there is a cold extremity, thrombosis may have occurred, and reexploration and removal of the blood clot should be considered.

An electrocardiogram is taken in the early postoperative period. Laboratory studies to evaluate the blood volume and kidney function are performed daily until the convalescence becomes uneventful. A tendency to paralytic ileus should be combatted by gastric suction until there is evidence that peristalsis has returned. Renal failure should be suspected if there has been preoperative evidence of impaired renal function or if there has been a prolonged period of hypotension.

If adequate hourly output of urine is not maintained despite an adequate intake, anuria should be suspected and appropriate therapy instituted.