Renal hemofiltration prevents metabolic acidosis and reduces inflammation during normothermic machine perfusion of the vascularized composite allograft: A preclinical study

Artif Organs. 2022 Feb;46(2):259-272. doi: 10.1111/aor.14089. Epub 2021 Nov 26.


Introduction: Recent experimental evidence suggests normothermic machine perfusion of the vascularized composite allograft results in improved preservation compared to static cold storage, with less reperfusion injury in the immediate post-operative period. However, metabolic acidosis is a common feature of vascularized composite allograft perfusion, primarily due to the inability to process metabolic by-products. We evaluated the impact of combined limb-kidney perfusion on markers of metabolic acidosis and inflammation in a porcine model.

Methods: Ten paired pig forelimbs were used for this study, grouped as either limb-only (LO, n = 5) perfusion, or limb-kidney (LK, n = 5) perfusion. Infrared thermal imaging was used to determine homogeneity of perfusion. Lactate, bicarbonate, base, pH, and electrolytes, along with an inflammatory profile generated via the quantification of cytokines and cell-free DNA in the perfusate were recorded.

Results: The addition of a kidney to a limb perfusion circuit resulted in the rapid stabilization of lactate, bicarbonate, base, and pH. Conversely, the LO circuit became progressively acidotic, correlating in a significant increase in pro-inflammatory cytokines. Global perfusion across the limb was more homogenous with LK compared to LO.

Conclusion: The addition of a kidney during limb perfusion results in significant improvements in perfusate biochemistry, with no evidence of metabolic acidosis.

Keywords: ex vivo normothermic perfusion; kidney perfusion; metabolic acidosis; vascularized composite allograft.

MeSH terms

  • Acidosis / prevention & control*
  • Animals
  • Composite Tissue Allografts*
  • Forelimb
  • Inflammation / prevention & control
  • Kidney / physiology*
  • Perfusion / methods*
  • Reperfusion Injury
  • Sus scrofa