Activation of rabbit aortic elastase by nonaortic intraabdominal surgery

The purpose of this study was to determine whether aortic elastase could be activated by distant operative trauma unrelated to direct aortic injury. One hundred rabbits were divided into five groups: group I - anesthesia only; group II - laparotomy only; group III - cecal resection; group IV - aortic mobilization; and group V - aortotomy with repair. Animals were sacrificed at one hour, three hours, six hours, one day, two days, and five days after surgery, and the aorta was analyzed for elastase activity. Operative trauma such as laparotomy, bowel resection, and mobilization of the aorta without direct aortic injury resulted in a significant increase in rabbit aortic elastase. The pattern of activation of rabbit aortic elastase within the laparotomy, aortic mobilization, and aortotomy groups was one of a slow rise to peak activation at 6-24 hours with a subsequent fall towards baseline at five days after surgery. This pattern differed in the cecal resection group in which activation occurred immediately with a slow fall towards baseline at five days. In none of the four surgical groups did the elastase activity return to baseline by five days after surgery. These data suggest that aortic elastase in rabbits can be activated by intraabdominal surgery unrelated to direct aortic injury.