Is blood a necessary component of the perfusate during isolated limb perfusion - a randomized controlled trial

Background: Isolated limb perfusion (ILP) is a treatment option for malignancies localized to an extremity and is performed by surgical isolation of the limb which is connected to an extracorporeal circulation system. A high concentration of a chemotherapeutic agent is perfused through the limb, while systemic toxicity is avoided. Currently, the use of packed red blood cells in the priming solution is the norm during ILP. The aim of this study was to investigate the possibility to replace an erythrocyte-based prime solution with a crystalloid-based prime solution while maintaining the regional metabolic oxygen demand during ILP. Methods: In a single-center, randomized controlled, non-blinded, non-inferiority clinical trial, 21 patients scheduled for treatment with ILP were included and randomized 1:1 to either an erythrocyte-based prime solution (control) or a crystalloid-based prime solution (intervention). Results: There was a significant difference in lactate level (mmol/L) during the perfusion between the intervention group and the control group (1.6 ± 0.4 vs. 3.6 ± 0.7, p = .001). No significant differences in oxygen extraction (%) (22 ± 11 vs. 14 ± 4, p = .06), oxygen delivery (ml/min) (90 ± 49 vs. 108 ± 38, p = .39), oxygen consumption (ml/min) (14 ± 2 vs. 14 ± 5, p = .85), regional central venous saturation (%) (83 ± 10 vs. 91 ± 4, p = .07) or INVOS (%) (76 ± 14 vs. 81 ± 11, p = .42) were found between the intervention group and the control group. Conclusion: This study showed no significant improvement with the addition of packed red blood cells into the prime solution in ensuring the metabolic oxygen demand in the treated extremity during ILP, and we, therefore, recommend that a crystalloid-based prime solution should be used.