A Simple Device to Obtain a Pulsatile Flow

Abstract

A simple device allowing a pulsatile flow to be obtained in isolated organ perfusion has been developed and applied to the vascular perfusion of isolated canine jejunal segments. The principle of the device consists of superimposing on a constant pressure produced by a roller pump, a pulsatile pressure of which the amplitude, frequency, and shape of the pulses can be adjusted separately and independently of the mean pressure value. The role of the arterial pulse in intestinal vascular perfusion has been studied by comparing the hemodynamic and metabolic behavior during alternate periods of pulsatile and nonpulsatile pumping. While no striking change in vascular resistance was observed, the O₂ consumption was significantly increased under pulsatile flow. These results testify to better metabolic conditions and enhanced organ functions under pulsatile pumping and also argue for improved intestinal microcirculation despite the constancy of the vascular resistance.

Machine Perfusion of the Pancreas: What Can We Learn from five Decades of Experimental Studies?

“…In 1974, Eloy et al presented the first study with Normothermic Machine Perfusion (NMP) of a canine pancreas, performed for 100min to test the secretory pancreas function [8]. This was paralleled by a first experimental comparison of 24hrs hypothermic machine perfusion (HMP) and SCS with subsequent transplantation of the canine pancreas [9].…”

“…Organ positioning is one key feature to avoid pressure necroses particularly during prolonged perfusion as recently described with full and partial human livers [44,45]. The first experimental pancreas study with NMP was done as early as in 1974 [8]. Until today, two studies describe NMP in discarded human pancreas (Table 1) and nine experimental non-transplant studies were published with pancreases from pigs, dogs or rodents (Supplementary baseline control group [42,43].…”

“…Animal studies further supported the recent findings with perfusion of human pancreases. Shorter endischemic NMP of 90min to 5hrs resulted in well-maintained tissue and limited inflammation [8,30,31,[49][50][51][52][53][54]. Most studies included DBD pancreas and lack a high risk donor model.…”

“…Various perfusate compositions were reported in the literature with autologous whole blood or washed erythrocytes as oxygen carriers in most recent studies [30,31,49]. Particularly in older studies the cold ischemia time before NMP is frequently not reported (Supplementary Table 2) [8,[52][53][54][55].…”

“…Dynamic preservation techniques have gained renewed attention in all solid organs. Despite the first application of this technology in pancreases as early as in 1974, the routine clinical use of such concepts lacks behind most other solid organs [7][8][9]. The first perfusion concept includes the recirculation of artificial perfusion fluids under cold conditions.…”