Anastomotic Blood-Flow Reduction in Rat Small Intestine with Chronic Radiation Damage

<b>Background/Aims: </b>Anastomoses in previously irradiated intestine are prone to leakage, possibly due to an impeded blood supply. Whether or not chronic radiation damage actually predisposes to a disturbed blood flow in the vicinity of anastomoses was investigated in the rat small bowel. <b>Method: </b>A 2-cm segment of rat ileum was irradiated with a single dose (21 Gy). After 20 weeks an anastomosis was created in the irradiated segment and in the corresponding segment of controls. Another 4 days later local blood flow was studied with the ¹⁴C-iodoantipyrine autoradiography technique in 16 sectors around the circumference both in the anastomotic segment and in a segment 4 mm apart. <b>Results: </b>In the anastomotic segment, the average blood flow was reduced in irradiated compared with non-irradiated animals in the mucosal layer (p = 0.034), but not in the muscular layer (p = 0.08). In the mesenteric quadrant blood flow was reduced in irradiated compared with non-irradiated animals, both in the mucosal layer (p = 0.012) and in the muscular layer (p = 0.05). More irradiated than non-irradiated animals showed a blood-flow reduction to 15% or more in 13–16 sectors both in the mucosal (p = 0.015) and the muscular layer (p = 0.04). <b>Conclusions: </b>The results favor the hypothesis that anastomoses in previously irradiated intestine are vascularly compromized and thereby have an increased risk of leakage.