LOCAL COLONIC BLOOD-PRESSURE DEGREE THROUGH AORTIC RECONSTRUCTION PROCEDURES - A PORCINE MODEL

Sigmoideal ischemia after aortic grafting is a severe complication wit h high morbidity and mortality. To investigate the basics of this circ ulatory problem an animal model was created with sigmoideal ischemia t hat could be quantified. For this purpose a new pig model was develope d with stable general circulatory and ventilatory parameters for sever al hours, while at the same rime controlled sigmoideal ischemia was in duced. In five pigs a left retroperitoneal approach to the aorta was p erformed to isolate the caudal mesenteric artery (CMA). Sigmoideal isc hemia was achieved by ligating the collateral circulation and constric ting the distal aorta. A flow probe,vas applied to the CMA. An intrava scular saturation probe was introduced in the caudal mesenteric vein ( CMV) and a pulse oximeter rr as applied to the serosal surface of the sigmoid. Every hour blood gas analyses from the carotic artery, CMA, a nd CMA were completed. Registrations of all circulatory and ventilator y parameters were performed with the help of a computer. The mean flow in the CMA was 29 mL/min (13-45) and decreased to 5 mL/min (3-7) afte r aortic constriction. Parameters reflecting the stability of the mode l, such as the cardiac index (mean 89 mL/min kg(-1)), the mixed venous oxygen saturation (mean 67%), and the total body oxygen consumption ( mean 3.3 mL/min kg(-1)), did not change with statistical significance during 4 h of partial aortic constriction. The conclusion is that a ne w model has been developed of quantitative sigmoideal ischemia in the pig that was stable for several hours.