Prevention of Intestinal Ischemia after Abdominal Aortic Replacement / 日本心臓血管外科学会雑誌

ABSTRACT

The stump pressure of the inferior mesenteric artery (IMA) was measured before and after aortic cross clamping during infra-renal abdominal aortic aneurysmal surgery in 50 cases. We analyzed the hemodynamics in IMA-supplied areas, and established an appropriate index to indicate intestinal ischemia. The IMA stump pressure after aortic cross clamping decreased significantly (<i>p</i><0.0001), by 11% on an average. This means that the collateral blood supply from the internal iliac artery (IIA) is 11% of the total pressure and the collateral blood supply from the superior mesenteric artery (SMA) is 89%, therefore the SMA supply dominates that of the IMA. Intestinal ileus due to ischemia occurred in one patient who had the highest rate of pressure decrease after aortic cross clamping. The cause of ileus might be poor collateral blood supply from SMA and insufficient IIA blood flow preservation. The IMA stump pressure might be an index to predict intestinal ischemia. We analyzed the IMA stump pressure in 38 cases without IMA reconstruction who had no ischemia. The ratio of 0.6 in IMA stump pressure versus systemic pressure could be a safe index suggesting sufficient blood flow in IMA-supplied areas. IMA reconstruction and IIA preservation should be performed to maintain an IMA stump pressure ratio of 0.6.