Normothermic Machine Perfusion in En Bloc Kidney Transplantation from Infant Donors: Two Innovative Surgical Approaches and Superior Clinical Efficacy

Introduction: Early graft loss and inferior graft function restrict the clinical application of infant donor kidneys. Ischemia–reperfusion injury (IRI) has been recognized as a key contributor to these adverse outcomes. In this study, using normothermic machine perfusion (NMP), we present two novel surgical techniques for en bloc kidney transplantation (EBKT) of infant donors that can fully or partially alleviate IRI, and compare their clinical efficacy with that of conventional en bloc kidney transplantation (C-EBKT) from infant donors.
Methods: We developed two novel surgical techniques for en bloc kidney transplantation (EBKT) from infant donors: ischemia-free en bloc kidney transplantation (NMP-IF-EBKT), in which NMP was applied during donor harvest, graft preservation, and implantation; and ischemia-free en bloc kidney implantation (NMP-IF-EBKI), in which NMP was used only during graft preservation and implantation. In the NMP-IF-EBKT group, no ischemia reperfusion injury (IRI) occurred in the donor kidneys, whereas in the NMP-IF-EBKI group, the donor kidneys sustained only brief IRI prior to NMP. Postoperative clinical data of these recipients, including renal function and complications, were collected and compared with conventional EBKT (C-EBKT).
Results: Totally 5 EBKT using the new techniques, including 2 cases of NMP-IF-EBKT and 3 cases of NMP-IF-EBKI, and compared with the prognostic outcome of 18 recipients of C-EBKT from infant donors in our center. Preoperative serum creatinine levels were comparable among the three groups. At postoperative weeks 1, 2, 3, and 4, mean serum creatinine levels in the NMP IF EBKT group were 128.5±68.6, 111.5±30.4, 111.0±9.9, and 103.0±42.4 μmol/L, respectively. Corresponding values in the C-EBKT group were 399.1±232.2, 213.6±107.9, 203.2±119.1, and 180.1±110.5 μmol/L, with P values of 0.06, 0.10, 0.15, and 0.18, respectively. Mean creatinine levels in the NMP-IF-EBKI group at the same time points were 373.2±221.4, 120.2±83.2, 122.1±78.4, and 160.2±126.3 μmol/L, which were higher than those in the C-EBKT group but without statistically significant differences. No postoperative complications were observed in the NMP groups, the incidence of DGF in the C-EBKT group recipients was 33.3% (6/18), and the incidence of vascular-related complications was 11.1% (2/18).
Conclusion: NMP-IF-EBKT and NMP-IF-EBKI are safe and feasible procedures that can theoretically completely or partially alleviate ischemic injury to donor organs during transplantation. Preliminary findings suggest that recipients undergoing these novel techniques exhibit more rapid postoperative renal function recovery and a lower incidence of complications. Further clinical studies with larger sample sizes are warranted to validate the efficacy of these surgical strategies.