Nicolas Goldaracena

Mechanism of hard-nanomaterial clearance by the liver

The liver and spleen are major biological barriers to translating nanomedicines because they sequester the majority of administered nanomaterials and prevent delivery to diseased tissue. Here we examined the blood clearance mechanism of administered hard nanomaterials in relation to blood flow dynamics, organ microarchitecture, and cellular phenotype. We found that nanomaterial velocity reduces 1000-fold as they enter and traverse the liver, leading to 7.5 times more nanomaterial interaction with hepatic cells relative to peripheral cells. In the liver, Kupffer cells (84.8%±6.4%), hepatic B cells (81.5±9.3%), and liver sinusoidal endothelial cells (64.6±13.7%) interacted with administered PEGylated quantum dots but splenic macrophages took up less (25.4±10.1%) due to differences in phenotype. The uptake patterns were similar for two other nanomaterial types and five different surface chemistries. Potential new strategies to overcome off-target nanomaterial accumulation may involve manipulating intra-organ flow dynamics and modulating cellular phenotype to alter hepatic cell interaction.

Normothermic ex vivo liver perfusion using steen solution as perfusate for human liver transplantation: First North American results.

The European trial investigating normothermic ex vivo liver perfusion (NEVLP) as a preservation technique for liver transplantation (LT) uses gelofusine, a non–US Food and Drug Administration–approved, bovine‐derived, gelatin‐based perfusion solution. We report a safety and feasibility clinical NEVLP trial with human albumin–based Steen solution. Transplant outcomes of 10 human liver grafts that were perfused on the Metra device at 37 °C with Steen solution, plus 3 units of erythrocytes were compared with a matched historical control group of 30 grafts using cold storage (CS) as the preservation technique. Ten liver grafts were perfused for 480 minutes (340‐580 minutes). All livers cleared lactate (final lactate 1.46 mmol/L; 0.56‐1.74 mmol/L) and produced bile (61 mL; 14‐146 mL) during perfusion. No technical problems occurred during perfusion, and all NEVLP‐preserved grafts functioned well after LT. NEVLP versus CS had lower aspartate aminotransferase and alanine aminotransferase values on postoperative days 1‐3 without reaching significance. No difference in postoperative graft function between NEVLP and CS grafts was detected as measured by day 7 international normalized ratio (1.1 [1‐1.56] versus 1.1 [1‐1.3]; P = 0.5) and bilirubin (1.5; 1‐7.7 mg/dL versus 2.78; 0.4‐15 mg/dL; P = 0.5). No difference was found in the duration of intensive care unit stay (median, 1 versus 2 days; range, 0‐8 versus 0‐23 days; P = 0.5) and posttransplant hospital stay (median, 11 versus 13 days; range, 8‐17 versus 7‐89 days; P = 0.23). Major complications (Dindo‐Clavien ≥ 3b) occurred in 1 patient in the NEVLP group (10%) compared with 7 (23%) patients in the CS group (P = 0.5). No graft loss or patient death was observed in either group. Liver preservation with normothermic ex vivo perfusion with the Metra device using Steen solution is safe and results in comparable outcomes to CS after LT. Using US Food and Drug Administration–approved Steen solution will avoid a potential regulatory barrier in North America. Liver Transplantation 22 1501–1508 2016 AASLD.

Subnormothermic ex vivo liver perfusion reduces endothelial cell and bile duct injury after donation after cardiac death pig liver transplantation

An ischemic‐type biliary stricture (ITBS) is a common feature after liver transplantation using donation after cardiac death (DCD) grafts. We compared sequential subnormothermic ex vivo liver perfusion (SNEVLP; 33°C) with cold storage (CS) for the prevention of ITBS in DCD liver grafts in pig liver transplantation (n = 5 for each group). Liver grafts were stored for 10 hours at 4°C (CS) or preserved with combined 7‐hour CS and 3‐hour SNEVLP. Parameters of hepatocyte [aspartate aminotransferase (AST), international normalized ratio (INR), factor V, and caspase 3 immunohistochemistry], endothelial cell (EC; CD31 immunohistochemistry and hyaluronic acid), and biliary injury and function [alkaline phosphatase (ALP), total bilirubin, and bile lactate dehydrogenase (LDH)] were determined. Long‐term survival (7 days) after transplantation was similar between the SNEVLP and CS groups (60% versus 40%, P = 0.13). No difference was observed between SNEVLP‐ and CS‐treated animals with respect to the peak of serum INR, factor V, or AST levels within 24 hours. CD31 staining 8 hours after transplantation demonstrated intact EC lining in SNEVLP‐treated livers (7.3 × 10−4 ± 2.6 × 10−4 cells/μm2) but not in CS‐treated livers (3.7 × 10−4 ± 1.3 × 10−4 cells/μm2, P = 0.03). Posttransplant SNEVLP animals had decreased serum ALP and serum bilirubin levels in comparison with CS animals. In addition, LDH in bile fluid was lower in SNEVLP pigs versus CS pigs (14 ± 10 versus 60 ± 18 μmol/L, P = 0.02). Bile duct histology revealed severe bile duct necrosis in 3 of 5 animals in the CS group but none in the SNEVLP group (P = 0.03). Sequential SNEVLP preservation of DCD grafts reduces bile duct and EC injury after liver transplantation. Liver Transpl 20:1296‐1305, 2014.

The extended Toronto criteria for liver transplantation in patients with hepatocellular carcinoma: A prospective validation study

The selection of liver transplant candidates with hepatocellular carcinoma (HCC) relies mostly on tumor size and number. Instead of relying on these factors, we used poor tumor differentiation and cancer‐related symptoms to exclude patients likely to have advanced HCC with aggressive biology. We initially reported similar 5‐year survival for patients whose tumors exceeded (M+ group) and were within (M group) the Milan criteria. Herein, we validate our original data with a new prospective cohort and report the long‐term follow‐up (10‐years) using an intention‐to‐treat analysis. The previously published study (cohort 1) included 362 listed (294 transplanted) patients from January 1996 to August 2008. The validation cohort (cohort 2) includes 243 listed (105 M+ group, 76 beyond University of California San Francisco criteria; 210 transplanted) patients from September 2008 to December 2012. Median follow‐up from listing was 59.7 (26.8‐103) months. For the validation cohort 2, the actuarial survival from transplant for the M+ group was similar to that of the M group at 1 year, 3 years, and 5 years: 94%, 76%, and 69% versus 95%, 82%, and 78% (P = 0.3). For the combined cohorts 1 and 2, there were no significant differences in the 10‐year actuarial survival from transplant between groups. On an intention‐to‐treat basis, the dropout rate was higher in the M+ group and the 5‐year and 10‐year survival rates from listing were decreased in the M+ group. An alpha‐fetoprotein level >500 ng/mL predicted poorer outcomes for both the M and M+ groups. Conclusion: Tumor differentiation and cancer‐related symptoms of HCC can be used to select patients with advanced HCC who are appropriate candidates for liver transplantation; alpha‐fetoprotein level limitations should be incorporated in the listing criteria for patients within or beyond the Milan criteria. (Hepatology 2016;64:2077‐2088)

Stereotactic body radiotherapy vs. TACE or RFA as a bridge to transplant in patients with hepatocellular carcinoma. An intention-to-treat analysis

BACKGROUND & AIMS There is limited information on the use of stereotactic body radiotherapy (SBRT) as a bridge to liver transplantation for hepatocellular carcinoma and no study comparing its efficacy to transarterial chemoembolization (TACE) and radiofrequency ablation (RFA). We aimed to ascertain the safety and efficacy of SBRT on an intention-to-treat basis compared with TACE and RFA as a bridge to liver transplantation in a large cohort of patients with hepatocellular carcinoma. METHODS Outcomes between groups were compared from the time of listing and from the time of transplant. Between July 2004 and December 2014, 379 patients were treated with either SBRT (n=36, SBRT group), TACE (n=99, TACE group) or RFA (n=244, RFA group). RESULTS The drop-out rate was similar between groups (16.7% SBRT group vs. 20.2% TACE group and 16.8% RFA group, p=0.7); 30 patients were transplanted in the SBRT group, 79 in the TACE group and 203 in the RFA group. Postoperative complications were similar between groups. Patients in the RFA group had more tumor necrosis in the explant. The 1-, 3- and 5-year actuarial patient survival from the time of listing was 83%, 61% and 61% in the SBRT group vs. 86%, 61% and 56% in the TACE group, and 86%, 72% and 61% in the RFA group, p=0.4. The 1-, 3- and 5-year survival from the time of transplant was 83%, 75% and 75% in the SBRT group vs. 96%, 75% and 69% in the TACE group, and 95%, 81% and 73% in the RFA group, p=0.7. CONCLUSIONS In conclusion, SBRT can be safely utilized as a bridge to LT in patients with HCC, as an alternative to conventional bridging therapies. LAY SUMMARY Patients with liver cancer included in the waiting list for liver transplantation are at risk of tumor progression and death. Stereotactic body radiotherapy may be a good alternative to conventional therapies to reduce this risk.

Eight-Hour Continuous Normothermic Ex Vivo Kidney Perfusion Is a Safe Preservation Technique for Kidney Transplantation: A New Opportunity for the Storage, Assessment, and Repair of Kidney Grafts.

Background Hypothermic kidney storage causes preservation injury and is poorly tolerated by renal grafts. We investigated whether static cold storage (SCS) can be safely replaced with a novel technique of pressure-controlled normothermic ex vivo kidney perfusion (NEVKP) in heart-beating donor kidney transplantation. Methods Right kidneys were removed from 30 kg Yorkshire pigs in a model of heart-beating donation and either preserved in cold histidine-tryptophan-ketoglutarate solution for 8 hours (n = 5), or subjected to 8 hours of pressure-controlled NEVKP (n = 5) followed by renal heterotopic autotransplantation. Results During NEVKP, physiologic perfusion conditions were maintained with low intrarenal resistance and normal electrolyte and pH parameters. Aspartate aminotransferase and lactate dehydrogenase as injury markers were below the detectable analyzer range (<4 and <100 U/L, respectively). Perfusate lactate concentration decreased from baseline until the end of perfusion (10.38 ± 0.76 mmol/L vs 1.22 ± 0.26 mmol/L; P < 0.001). Posttransplantation, animals transplanted with NEVKP versus SCS grafts demonstrated similar serum creatinine peak levels (NEVKP, 2.0 ± 0.5 vs SCS 2.7 ± 0.7 mg/dL; P = 0.11) and creatinine clearance on day 10 (NEVKP, 65.9 ± 18.8 mL/min vs SCS 61.2 ± 15.6 mL/min; P = 0.74). After 10 days of follow-up, animals transplanted with NEVKP grafts had serum creatinine and blood urea nitrogen values comparable to their basal levels (P = 0.49 and P = 0.59), whereas animals transplanted with SCS grafts had persistently elevated serum creatinine and blood urea nitrogen when compared with basal levels (P = 0.01 and P = 0.03). Conclusions Continuous pressure-controlled NEVKP is feasible and safe in good quality heart-beating donor kidney grafts. It maintains a physiologic environment and excellent graft function ex vivo during preservation without causing graft injury.

Living vs. deceased donor liver transplantation provides comparable recovery of renal function in patients with hepatorenal syndrome: a matched case-control study.

Outcomes of living versus deceased donor liver transplantation in patients with chronic liver disease and hepatorenal syndrome (HRS) was compared using a matched pair study design. Thirty patients with HRS receiving a live donor liver transplantation (LDLT) and 90 HRS patients receiving a full graft deceased donor liver transplantation (DDLT) were compared. LDLT versus DDLT of patients with HRS was associated with decreased peak aspartate aminotransferase levels (339 ± 214 vs. 935 ± 1253 U/L; p = 0.0001), and similar 7‐day bilirubin (8.42 ± 7.89 vs. 6.95 ± 7.13 mg/dL; p = 0.35), and international normalized ratio levels (1.93 ± 0.62 vs. 1.78 ± 0.78; p = 0.314). LDLT vs. DDLT had a decreased intensive care unit (2 [1–39] vs. 4 [0–93] days; p = 0.004), and hospital stay (17 [4–313] vs. 26 [0–126] days; p = 0.016) and a similar incidence of overall postoperative complications (20% vs. 27%; p = 0.62). No difference was detected between LDLT and DDLT patients regarding graft survival at 1 (80% vs. 82%), at 3 (69% vs. 76%) and 5 years (65% vs. 76%) (p = 0.63), as well as patient survival at 1 (83% vs. 82%), 3 (72% vs. 77%) and 5 years (72% vs. 77%) (p = 0.93). The incidence of chronic kidney disease post‐LT (10% vs. 6%; p = 0.4) was similar between both groups. LDLT results in identical long‐term outcome when compared with DDLT in patients with HRS.

Live Donor Liver Transplantation: A Valid Alternative for Critically Ill Patients Suffering From Acute Liver Failure

We report the outcome of live donor liver transplantation (LDLT) for patients suffering from acute liver failure (ALF). From 2006 to 2013, all patients with ALF who received a LDLT (n = 7) at our institution were compared to all ALF patients receiving a deceased donor liver transplantation (DDLT = 26). Groups were comparable regarding pretransplant ICU stay (DDLT: 1 [0–7] vs. LDLT: 1 days [0–10]; p = 0.38), mechanical ventilation support (DDLT: 69% vs. LDLT: 57%; p = 0.66), inotropic drug requirement (DDLT: 27% vs. LDLT: 43%; p = 0.64) and dialysis (DDLT: 2 vs. LDLT: 0 patients; p = 1). Median evaluation time for live donors was 24 h (18–72 h). LDLT versus DDLT had similar incidence of overall postoperative complications (31% vs. 43%; p = 0.66). No difference was detected between LDLT and DDLT patients regarding 1‐ (DDLT: 92% vs. LDLT: 86%), 3‐ (DDLT: 92% vs. LDLT: 86%), and 5‐ (DDLT: 92% vs. LDLT: 86%) year graft and patient survival (p = 0.63). No severe donor complication (Dindo–Clavien ≥3 b) occurred after live liver donation. ALF is a severe disease with high mortality on liver transplant waiting lists worldwide. Therefore, LDLT is an attractive option since live donor work‐up can be expedited and liver transplantation can be performed within 24 h with excellent short‐ and long‐term outcomes.

Subnormothermic ex vivo liver perfusion is a safe alternative to cold static storage for preserving standard criteria grafts

We developed a novel technique of subnormothermic ex vivo liver perfusion (SNEVLP) for the storage of liver grafts before transplantation. To test the safety of SNEVLP for the nonextended criteria grafts (standard grafts), we compared it to a control group with minimal cold static storage (CS) time. Heart‐beating pig liver retrieval was performed. Grafts were either stored in cold unmodified University of Wisconsin solution (CS‐1), in cold University of Wisconsin solution with ex vivo perfusion additives (CS‐2), or preserved with a sequence of 3 hours CS and 3 hours SNEVLP (33°C), followed by orthotopic liver transplantation. Liver function tests and histology were investigated. Aspartate aminotransferase (AST) levels during SNEVLP remained stable (54.3 ± 12.6 U/L at 1 hour to 47.0 ± 31.9 U/L at 3 hours). Posttransplantation, SNEVLP versus CS‐1 livers had decreased AST levels (peak at day 1, 1081.9 ± 788.5 versus 1546.7 ± 509.3 U/L; P = 0.14; at day 2, 316.7 ± 188.1 versus 948.2 ± 740.9 U/L; P = 0.04) and alkaline phosphatase levels (peak at day 1, 150.4 ± 19.3 versus 203.7 ± 33.6 U/L; P = 0.003). Bilirubin levels were constantly within the physiological range in the SNEVLP group, whereas the CS‐1 group presented a large standard deviation, including pathologically increased values. Hyaluronic acid as a marker of endothelial cell (EC) function was markedly improved by SNEVLP during the early posttransplant phase (5 hours posttransplant, 1172.75 ± 598.5 versus 5540.5 ± 2755.4 ng/mL). Peak international normalized ratio was similar between SNEVLP and CS‐1 groups after transplantation. Immunohistochemistry for cleaved caspase 3 demonstrated more apoptotic sinusoidal cells in the CS‐1 group when compared to SNEVLP grafts 2 hours after reperfusion (19.4 ± 19.5 versus 133.2 ± 48.8 cells/high‐power field; P = 0.002). Adding normothermic CS‐2 had no impact on liver injury or function after transplantation when compared to CS‐1. In conclusion, SNEVLP is safe to use for standard donor grafts and is associated with improved EC and bile duct injury even in grafts with minimal CS time. Liver Transpl 22:111‐119, 2016.

Live Donor Liver Transplantation With Older (≥50 Years) Versus Younger (<50 Years) Donors: Does Age Matter?

Objective:To compare the outcome of adult live donor liver transplantation (LDLT) with grafts from older versus younger donors. Introduction:Using older donor grafts for adult LDLT may help expand the donor pool. However, the risks of LDLT with older donors remain controversial, and many centers are reluctant to use live donors aged 45 years or older for adult LDLT. Methods:Outcomes of patients receiving a LDLT graft from donors aged 50 years or older (n = 91) were compared with those receiving a live donor graft from donors younger than 50 years (n = 378). Results:Incidences of biliary (LDLT <50: 24% vs LDLT ≥50: 23%; P = 0.89) and major complications (LDLT <50: 24% vs LDLT ≥50: 24%; P = 1) were similar between both groups of recipients. No difference was observed in 30-day recipient mortality (LDLT <50: 3% vs LDLT ≥50: 0%; P = 0.13). The 1- (90% vs 90%), 5- (82% vs 73%), and 10- (71% vs 58%) year graft survival was statistically similar between both groups (P = 0.075). Likewise, patient survival after 1- (92% vs 96%), 5- (83% vs 79%), and 10- (76% vs 69%) years was also similar (P = 0.686). Overall, donors rate of major complications (Dindo-Clavien ≥3b) within 30 days was low (n = 2.3%) and not different in older versus younger donors (P = 1). Donor median hospital stay in both groups was identical [LDLT <50: 6 (4–17) vs LDLT ≥50: 6 (4–14) days; P = 0.65]. No donor death occurred and all donors had full recovery and returned to baseline activity. Conclusions:Right lobe LDLT with donors aged 50 years or older results in acceptable recipient outcome without increased donor morbidity or mortality. Potential live donors should not be declined on the basis of age alone.