Hypothermic Oxygenated Perfusion for Transplantation of a Pediatric Extended Right Lobe: Report of the First Case.

Abstract

Ongoing shortage of donor organs still represents a relevant problem in transplantation medicine. Use of extended criteria donor organs, living donation, and ex vivo splitting have been the major strategies to extend the donor pool for liver transplantation within the past years.1 Recently, the revival of ex vivo machine perfusion has opened up new opportunities to fight organ shortage.2 Especially extended criteria donor organs have been shown to substantially profit from hypothermic oxygenated perfusion (HOPE) prior to transplant.3,4 Combining several of the aforementioned approaches thus might generate synergistic effects and further increase the rate of organs deemed suitable for transplantation. By this means, Mabrut et al5 demonstrated the general feasibility of performing the ex vivo splitting procedure during normothermic machine perfusion. Thorne et al6 showed that extended right lobes (ERLs) generated from ex vivo splitting, usually exposed to prolonged cold ischemic time (CIT), indeed benefit from HOPE. HOPE was recently successfully applied even in pediatric liver transplantation.7 We have now applied HOPE for pretransplant conditioning of a pediatric ERL to avoid loss of the potential graft due to prolonged CIT or posttransplant cholangiopathy. In brief, a 9-y-old female child suffering from cirrhosis due to familiar intrahepatic cholestasis type 2 in reduced condition (hepatic osteopathy and recurrent decompensation amongst others) was offered an ERL following ex situ splitting of a 6-y-old male donor organ. The donor was diagnosed brain dead following traumatic brain injury. Regarding the course of the laboratory findings and the organ quality and anatomy, the donor liver (803 g) was deemed suitable for an ex vivo splitting procedure. Following an uncomplicated split, the ERL of 508 g was accepted for our patient in an extended allocation following rejection of the ERL by the primary center due to size mismatch (ERL accepted for an adult recipient). Because of the overall demanding logistics, the estimated CIT eventually was expected to be >16 h. In order to preserve the organ for transplantation, we thus decided ad hoc to perform HOPE of the ERL to counter the expected increased ischemia reperfusion injury following the prolonged CIT. HOPE via the portal vein was performed using oxygenated University of Wisconsin perfusion solution (VitaSmart, Bridge to Life, UK) with maximum pressure and flow set at 3 mm Hg and 175 mL/min, respectively (Figure 1). HOPE was maintained for 200 min followed by flush of the ERL at the end of perfusion with ice-cold custodiol solution. The transplant procedure itself was uneventful with reconstruction of the right liver artery of the donor to an aberrant right liver artery of the recipient by end-to-end anastomosis. Reperfusion of the graft likewise was uneventful without any signs of postreperfusion syndrome despite 16 h 23 min of CIT. Primary closure of the abdomen was achieved with immediate uptake of liver function regarding regular lactate clearance and courses of transaminases, international normalized ratio, and bilirubin (Figure 1). The child was extubated the same day and discharged from intensive care unit on the next day (total length of hospital stay: 21 d). Apart from a biopsy-proven, mild acute rejection episode in week 5, well responsible to steroid treatment, the postoperative course was uneventful with regular graft function at 3 mo after transplantation and absence of any signs of posttransplant cholangiopathy.FIGURE 1.: Hypothermic oxygenated perfusion of a pediatric extended right lobe: Following ex situ splitting of the liver and cold static storage of 13 h 3 min, the extended right lobe was treated for 200 min by hypothermic oxygenated perfusion (HOPE) via the portal vein prior to implant (A). Transplantation was uneventful with rapid homogenous reperfusion and no signs of postreperfusion syndrome, and the liver graft showed regular lactate clearance (B) and uptake of liver function in the course (C). ALT, alanine transaminase; γ-GT, gamma-glutamyl transferase; INR, international normalized ratio.To our knowledge, this is the first report demonstrating the effective use of HOPE for transplantation of a pediatric ERL. Based on this single-case experience, pressure-controlled perfusion of the pediatric organ seems safe. Potential benefits of HOPE in terms of reducing ischemia reperfusion injury might also apply to pediatric organs.