Effect of a leukocyte-depleting filter in an extracorporeal circuit used for low-flow ischemia and reperfusion of equine jejunum.

This research aims to investigate the impact of leukocyte depletion on the variables of equine jejunum following the simulation of arterial low-flow ischemia and reperfusion through an extracorporeal circuit.

Methodology

• Researchers conducted the experiment on 14 healthy adult horses.
• The team removed a segment of jejunum surgically and maintained it in an isolated circuit for three hours (the control group).
• To simulate a condition of low blood supply, the arterial flow was reduced to 20% of the baseline for 40 minutes, followed by a reperfusion period of one hour (low-flow group).
• In the final experimental group, the researchers filtered out leukocytes (a type of white blood cell) before going through the process of low-flow ischemia and reperfusion as in the low-flow control group (filter-treated group).
• Various metabolic, hemodynamic, and histomorphologic variables were evaluated, including effects of electrical field stimulation and L-N-nitro-arginine-methyl-ester (L-NAME) on contractile activity.

Results

• The extracorporeal circuit seemed to maintain the jejunum within physiologic limits for an extended period.
• Low-flow ischemia with reperfusion induced significant differences in various measurements, compared with control specimens.
• However, significant differences were not evident between the low-flow and filter-treated groups, indicating that leukocyte depletion did not significantly alter the results.
• The researchers noted myeloperoxidase activity, linked to inflammation, was higher in the low-flow group than in the control group. The difference in this activity was not detected between the control and filter-treated groups.

Conclusions

• The researchers concluded that the extracorporeal circuit was successful in maintaining the jejunum in a functioning state for up to three hours and could be used to simulate tissues’ injury.
• However, leukocyte depletion generally did not attenuate the effects of low-flow ischemia and reperfusion on the equine small intestine, suggesting the presence or absence of these cells had limited effect on the overall ischemia and reperfusion outcome.