Background and Aims: In liver transplantation, cold preservation induces ischemia, resulting in significant reperfusion injury. Hypothermic oxygenated machine perfusion (HMP-O₂) has shown benefits compared to static cold storage (SCS) by limiting ischemia-reperfusion injury. This study reports outcomes using a novel portable HMP-O₂ device in the first US randomized control trial. Approach and Results: The PILOT trial (NCT03484455) was a multicenter, randomized, open-label, noninferiority trial, with participants randomized to HMP-O₂ or SCS. HMP-O₂ livers were preserved using the Lifeport Liver Transporter and Vasosol perfusion solution. The primary outcome was early allograft dysfunction. Noninferiority margin was 7.5%. From April 3, 2019, to July 12, 2022, 179 patients were randomized to HMP-O₂ (n=90) or SCS (n=89). The per-protocol cohort included 63 HMP-O₂ and 73 SCS. Early allograft dysfunction occurred in 11.1% HMP-O₂ (N=7) and 16.4% SCS (N=12). The risk difference between HMP-O₂ and SCS was −5.33% (one-sided 95% upper confidence limit of 5.81%), establishing noninferiority. The risk of graft failure as predicted by Liver Graft Assessment Following Transplant score at seven days (L-GrAFT₇) was lower with HMP-O₂ [median (IQR) 3.4% (2.4–6.5) vs. 4.5% (2.9–9.4), p=0.024]. Primary nonfunction occurred in 2.2% of all SCS (n=3, p=0.10). Biliary strictures occurred in 16.4% SCS (n=12) and 6.3% (n=4) HMP-O₂ (p=0.18). Nonanastomotic biliary strictures occurred only in SCS (n=4). Conclusions: HMP-O₂ demonstrates safety and noninferior efficacy for liver graft preservation in comparison to SCS. Early allograft failure by L-GrAFT₇ was lower in HMP-O₂, suggesting improved early clinical function. Recipients of HMP-O₂ livers also demonstrated a lower incidence of primary nonfunction and biliary strictures, although this difference did not reach significance.

Elderly patients are evaluated for liver transplantation (LT) with increasing frequency, but outcomes in this group have not been well defined. A linkage of the Scientific Registry of Transplant Recipients (SRTR) and the University HealthSystem Consortium (UHC) databases identified 12,445 patients who underwent LT during 2007-2011. Two cohorts were created consisting of, respectively, elderly recipients aged ≥70 years (n = 323) and recipients aged 18-69 years (n = 12,122). A 1:1 case-matched analysis was performed based on propensity scores. Elderly recipients had lower Model for End-stage Liver Disease (MELD) scores at LT (median 15 versus 19; P < 0.0001), more often underwent transplantation at high-volume centres (46% versus 33%; P < 0.0001) and more often received grafts from donors aged >60 years (24% versus 15%; P < 0.0001). The two cohorts had similar hospital lengths of stay, in-hospital mortality, hospital costs and 30-day readmission rates. There were no differences in graft survival between the two cohorts (P = 0.10), but elderly recipients had worse longterm overall survival (P = 0.009). However, a case-controlled analysis confirmed similar perioperative hospital outcomes, graft survival and longterm patient survival in the two matched cohorts. Elderly LT recipients accounted for <3% of all LTs performed during 2007-2011. Selected elderly recipients have perioperative outcomes and survival similar to those in younger adults.

The aim of this study was to analyze the impact of morbid obesity in recipients on peritransplant resource utilization and survival outcomes. Using a linkage between the University HealthSystem Consortium and Scientific Registry of Transplant Recipients databases, we identified 12 445 patients who underwent liver transplantation (LT) between 2007 and 2011 and divided them into two cohorts based on recipient body mass index (BMI; <40 vs. ≥40 kg/m²). Recipients with BMI ≥40 comprised 3.3% (n = 416) of all LTs in the studied population. There were no significant differences in donor characteristics between two groups. Recipients with BMI ≥40 were significant for being female, diabetic, and with NASH cirrhosis. Patients with a BMI ≥40 had a higher median MELD score, limited physical capacity, and were more likely to be hospitalized at LT. BMI ≥40 recipients had higher post-LT length of stay and were less often discharged to home. With a median follow-up of 2 years, patient and graft survival were equivalent between the two groups. In conclusion, morbidly obese LT recipients appear sicker at time of LT with an increase in resource utilization but have similar short-term outcomes.