Physiological alterations secondary to perfusion and revascularization of canine intestine

Our studies suggest that the perfusion rates of canine intestinal segments during extracorporeal perfusion are directly related to the quality of preservation; namely, better preserved specimens exhibit higher perfusion rates and vice versa. Production of intraluminal fluid (ILF) during preservation and following revascularization is related to the quality of preservation. Poorly preserved intestine seems generally to produce more fluid than well preserved specimens. Conversely, continuous pulsatile perfusion techniques resulted in more ILF production than specimens perfused with low-flow gravity-dependent systems. Ex vivo intestinal perfusion resulted in organ oedema inversely proportional to the quality of preservation. Poor preservation is also associated with washout of potassium, lactic dehydrogenase, and tissue acidosis both during preservation and revascularization. Perfusion with a high concentration of potassium ions results in poor preservation presumably owing to vasoconstriction. Mucosal malperfusion as demonstrated by the Microfil technique is the circulatory abnormality most closely associated with inadequate preservation. Smooth-muscle function, as measured by electrical activity recordings, is well preserved by pulsatile flow methods, whereas gravity perfusion results in disorganized and spastic muscular activity. The best preservation appeared to be obtained by the use of pulsatile flow with cryoprecipitated plasma as the perfusate.