Effects of long-term extracorporeal blood perfusion of the distal portion of isolated equine forelimbs on metabolic variables and morphology of laminar tissue

Abstract

Isolated equine limbs were perfused under physiologic conditions over a period of < or = 10 hours without structural damage to the laminar tissue.

Extracorporeal perfusion of isolated organs of large animals – Bridging the gap between in vitro and in vivo studies

“…1). An equilibration period with a low flow rate that is gradually increased allows the specimen to warm slowly and prevents edema formation (Wüstenberg, 2006;Patan et al, 2009).…”

“…For perfusates containing erythrocytes, such as blood/plasma (Patan et al, 2009) or blood/dialysate mixtures (Wagner et al, 2003), room air is adequate to achieve satisfactory saturation of the perfusate while a low flow rate may support sufficient time for gas exchange in the oxygenation system (Wagner et al, 2003).…”

“…If temporary storage or transport of the organ is necessary, the duration of warm ischemia should be kept as short as possible. Therefore, after the cold flush, specimens should also be cooled externally to further reduce metabolism (Patan et al, 2009). This is best achieved by wrapping specimens with swabs soaked in electrolyte solution or by complete immersion in a plastic bag and storage on ice (VanGiesen et al, 1983).…”

“…So, despite the reduced concentration of oxygen carriers due to its dilution, the improved flow rate leads to better tissue supply and consequently to superior organ function (Dittrich et al, 2000). For dilution purposes, plasma (Patan et al, 2009) or artificial solutions such as Tyrode solution (Friebe et al, 2013b), modified Krebs-Henseleit buffer (Mancina et al, 2015) or dialysate solution (acetate hemodialysis concentrate HD 22, Fresenius Medical Care, Bad Homburg, Germany) (Wagner et al, 2003) have been used successfully.…”

“…These systems generally follow the same concept as rotating disc oxygenators, as oxygen exchange occurs at a porous membrane. A simple but effective adaptation of this principle is the use of gas-permeable tubing exposed to room air in a custom made oxygenation chamber, which has been shown to be effective for oxygenation of media containing erythrocytes (Hamilton et al, 1974;Patan et al, 2009).…”