Hypothermic Machine Perfusion of Liver Grafts Can Safely Extend Cold Ischemia for Up to 20 Hours in Cases of Necessity
In the first case, a 42-year-old woman was referred to our center for urgent LT because of acute hepatic failure and hepatic artery thrombosis after pancreaticoduodenectomy for ampullary adenoma. The donor was a 65-year-old brain-dead female patient who died from spontaneous brain hemorrhage. Laparotomy performed on the recipient revealed extensive intestinal necrosis and complete hepatic artery and portal vein thrombosis, which made LT impractical and futile. Another recipient, a 66-year-old female patient with hepatocellular carcinoma and hepatitis C virus (HCV) cirrhosis, was selected. The retrieved liver was connected to an HMP Liver Assist (Organ Assist B.V., Groningen, The Netherlands) after 12:15 hours of SCS, which provided additional time to organize the recipient’s transport and preparation for LT.
In the second case, a liver from an 18-year-old male donor, who was brain dead due to traumatic brain injury, was initially offered to another center and retrieved for combined lung and liver transplantation. Because the recipient developed severe hemodynamic instability after lung implantation, the surgeons decided not to proceed with LT. Subsequently, the liver was offered to our center and connected to HMP after 12:10 hours of SCS, to provide time to prepare the recipient (a 61-year-old female patient with hepatocellular carcinoma and hepatitis C virus cirrhosis).
In both cases, the grafts were perfused with cooled (10 °C) and oxygenated Belzer MPS solution (Bridge to Life Ltd., Columbia, SC) from the portal vein (4 mmHg) and the hepatic artery (25 mmHg), with continuous and pulsatile flow, respectively. Vascular resistances during perfusion are shown in Figure 1A. Specific informed consent was obtained before the procedure. Biliary production was observed immediately after portal reperfusion. Total CIT was 18:15 hours in the first case and 20:00 hours in the second case. In both cases, the postoperative course was normal (Figure 1B) and without complications during follow-up of 9 and 4 months, for the first and second cases, respectively.
Prolonged CIT has been associated with a high incidence of early graft dysfunction and primary nonfunction.3 More than 25 years ago, Pienaar demonstrated the benefits of HMP in long-term liver preservation, reporting successful LTs after 72 hours of perfusion in a dog series.1 However, clinical reports on the logistical advantage of HMP are surprisingly rare.4 In our experience, despite the extraordinarily prolonged CIT, we observed excellent functional recovery. Our results are likely multifactorial and obviously influenced by the good graft quality and the donor-recipient matching. Nevertheless, the surprisingly low transaminase peaks posttransplant were indicative of minimal graft preservation injury. We did not observe the time-dependent increase in vascular resistances reported by other authors during prolonged perfusion,5 which was likely because HMP was initiated after SCS and the time of perfusion was limited in both cases despite the prolonged total CIT.
In conclusion, our experience suggests that, in cases where unexpected problems delay the ordinary transplant process, HMP can be used to prolong CIT with high-quality preservation and allow utilization of grafts that otherwise would be discharged because of logistical problems.