Effect of pulseless perfusion on gastrointestinal blood flow and its distribution.

The effect of nonpulsatile (NP) arterial perfusion on gastrointestinal organ blood flow and intraorgan flow distribution was studied in 10 anesthetized (pentobarbital) dogs utilizing the radionuclide-labeled microsphere (15 micrometer) technique. Measurements of flow to the stomach, small intestine, and colon were made during a pulsatile perfusion control period and after 1- and 2-h periods of NP perfusion with a centrifugal left ventricular bypass pump (Medtronic). Total gastric blood flow (0.178 +/- 0.021 ml/min per g) as well as the partitioning of that flow between gastric subsegments such as antrum (17% of total gastric flow), body (83%), and mucosa (73%) was not significantly altered during the 2-h period of NP perfusion (P greater than 0.20). Similarly, flow to the intestine showed significant change during NP perfusion. Under conditions of equivalent hemodynamic states (mean perfusion pressure), nonpulsatile arterial perfusion results in no significant alteration in gastrointestinal blood flow or its intraorgan distribution.