Alternative forms of portal vein revascularization in liver transplant recipients with complex portal vein thrombosis.

BACKGROUND & AIMS: Complex portal vein thrombosis (PVT) is a challenge in liver transplantation (LT). Extra-anatomical approaches to portal revascularization, including renoportal (RPA), left gastric vein (LGA), pericholedochal vein (PCA), and cavoportal (CPA) anastomoses, have been described in case reports and series. The RP4LT Collaborative was created to record cases of alternative portal revascularization performed for complex PVT. METHODS: An international, observational web registry was launched in 2020. Cases of complex PVT undergoing first LT performed with RPA, LGA, PCA, or CPA were recorded and updated through 12/2021. RESULTS: A total of 140 cases were available for analysis: 74 RPA, 18 LGA, 20 PCA, and 28 CPA. Transplants were primarily performed with whole livers (98%) in recipients with median (IQR) age 58 (49-63) years, model for end-stage liver disease score 17 (14-24), and cold ischemia 431 (360-505) minutes. Post-operatively, 49% of recipients developed acute kidney injury, 16% diuretic-responsive ascites, 9% refractory ascites (29% with CPA, p <0.001), and 10% variceal hemorrhage (25% with CPA, p = 0.002). After a median follow-up of 22 (4-67) months, patient and graft 1-/3-/5-year survival rates were 71/67/61% and 69/63/57%, respectively. On multivariate Cox proportional hazards analysis, the only factor significantly and independently associated with all-cause graft loss was non-physiological portal vein reconstruction in which all graft portal inflow arose from recipient systemic circulation (hazard ratio 6.639, 95% CI 2.159-20.422, p = 0.001). CONCLUSIONS: Alternative forms of portal vein anastomosis achieving physiological portal inflow (i.e., at least some recipient splanchnic blood flow reaching transplant graft) offer acceptable post-transplant results in LT candidates with complex PVT. On the contrary, non-physiological portal vein anastomoses fail to resolve portal hypertension and should not be performed. IMPACT AND IMPLICATIONS: Complex portal vein thrombosis (PVT) is a challenge in liver transplantation. Results of this international, multicenter analysis may be used to guide clinical decisions in transplant candidates with complex PVT. Extra-anatomical portal vein anastomoses that allow for at least some recipient splanchnic blood flow to the transplant allograft offer acceptable results. On the other hand, anastomoses that deliver only systemic blood flow to the allograft fail to resolve portal hypertension and should not be performed.

Hypoxia-inducible factor-1α-dependent induction of miR122 enhances hepatic ischemia tolerance.

Hepatic ischemia and reperfusion (IR) injury contributes to the morbidity and mortality associated with liver transplantation. microRNAs (miRNAs) constitute a family of noncoding RNAs that regulate gene expression at the posttranslational level through the repression of specific target genes. Here, we hypothesized that miRNAs could be targeted to enhance hepatic ischemia tolerance. A miRNA screen in a murine model of hepatic IR injury pointed us toward the liver-specific miRNA miR122. Subsequent studies in mice with hepatocyte-specific deletion of miR122 (miR122loxP/loxP Alb-Cre+ mice) during hepatic ischemia and reperfusion revealed exacerbated liver injury. Transcriptional studies implicated hypoxia-inducible factor-1α (HIF1α) in the induction of miR122 and identified the oxygen-sensing prolyl hydroxylase domain 1 (PHD1) as a miR122 target. Further studies indicated that HIF1α-dependent induction of miR122 participated in a feed-forward pathway for liver protection via the enhancement of hepatic HIF responses through PHD1 repression. Moreover, pharmacologic studies utilizing nanoparticle-mediated miR122 overexpression demonstrated attenuated liver injury. Finally, proof-of-principle studies in patients undergoing orthotopic liver transplantation showed elevated miR122 levels in conjunction with the repression of PHD1 in post-ischemic liver biopsies. Taken together, the present findings provide molecular insight into the functional role of miR122 in enhancing hepatic ischemia tolerance and suggest the potential utility of pharmacologic interventions targeting miR122 to dampen hepatic injury during liver transplantation.

Eosinophils attenuate hepatic ischemia-reperfusion injury in mice through ST2-dependent IL-13 production.

Eosinophils are a myeloid cell subpopulation that mediates type 2 T helper cell immune responses. Unexpectedly, we identified a rapid accumulation of eosinophils in 22 human liver grafts after hepatic transplantation. In contrast, no eosinophils were detectable in healthy liver tissues before transplantation. Studies with two genetic mouse models of eosinophil deficiency and a mouse model of antibody-mediated eosinophil depletion revealed exacerbated liver injury after hepatic ischemia and reperfusion. Adoptive transfer of bone marrow-derived eosinophils normalized liver injury of eosinophil-deficient mice and reduced hepatic ischemia and reperfusion injury in wild-type mice. Mechanistic studies combining genetic and adoptive transfer approaches identified a critical role of suppression of tumorigenicity (ST2)-dependent production of interleukin-13 by eosinophils in the hepatoprotection against ischemia-reperfusion-induced injury. Together, these data provide insight into a mechanism of eosinophil-mediated liver protection that could serve as a therapeutic target to improve outcomes of patients undergoing liver transplantation.

A biopsychosocial approach to liver transplant evaluation in two patients with Wilson's disease.

Wilson's disease (WD) is characterized by hepatic, neurological, and/or psychiatric disturbances. In some cases, liver transplantation is indicated. Because psychologists and other health care workers play an increasing role in the evaluation of individuals presenting for transplant, an understanding of the heterogeneous phenotype of WD is important for mental health professionals working in medical settings. This article reviews two cases of patients with WD (one probable, one confirmed) presenting for liver transplantation and a biopsychosocial assessment approach is demonstrated. Patients are presented in terms of medical, psychiatric, and psychosocial history, neuropsychological examination results, and the subsequent indications for liver transplantation. Both patients exhibited neurocognitive and psychiatric symptoms. One patient was determined to be a marginally suitable candidate for transplantation, whereas the other was considered at high risk for negative outcome post-transplant. This article demonstrates the importance of considering phenotypic presentation, neurocognitive function, psychiatric status, and psychosocial circumstances in assessing transplant readiness in patients with WD. A comprehensive and integrative biopsychosocial assessment approach is appropriate for evaluating patients with WD presenting for liver transplantation.

Transmission of Cryptococcus neoformans by Organ Transplantation.

BACKGROUND: This article describes transmission of Cryptococcus neoformans by solid organ transplantation. METHODS: We reviewed medical records and performed molecular genotyping of isolates to determine potential for donor transmission of Cryptococcus. RESULTS: Cryptococcosis was diagnosed in 3 recipients of organs from a common donor with an undifferentiated neurologic condition at the time of death. Cryptococcal meningoencephalitis was later diagnosed in the donor at autopsy. The liver and 1 kidney recipient developed cryptococcemia and pneumonia and the other kidney recipient developed cryptococcemia and meningitis; 2 patients recovered with prolonged antifungal therapy. We tested 4 recipient isolates with multilocus sequence typing and found they had identical alleles. CONCLUSIONS: Our investigation documents the transmission of Cryptococcus neoformans by organ transplantation. Evaluation for cryptococcosis in donors with unexplained neurologic symptoms should be strongly considered.

Radiofrequency ablation for unresectable tumors of the liver.

Surgical resection of primary or metastatic tumors of the liver offers patients the best long-term survival. Liver resections may not be appropriate in patients with bilobar metastases, liver dysfunction, or severe comorbidities. Radiofrequency ablation (RFA) is a technique used to destroy unresectable hepatic tumors through thermocoagulation. We retrospectively reviewed a consecutive series of patients undergoing RFA with unresectable hepatic tumors for local recurrence and overall survival. Under an Institutional Review Board-approved protocol, all patients treated with RFA at the University of Alabama at Birmingham from September 1, 1998, to June 15, 2005, were identified. During this time period, 189 lesions in 107 patients were treated with RFA. Patients' charts were retrospectively reviewed. Data is presented as mean +/- SEM. Significance is defined as P < 0.05. Patient demographics revealed 62 per cent males and 38 per cent females with a mean age of 59 (+/- 1) years. Hepatocellular carcinoma (HCC) represented 54 per cent of the tumors treated. Metastatic colorectal cancer represented 22 per cent and the remaining 24 per cent were other metastatic tumors. Overall recurrence rates for all tumors after RFA was 53 per cent. Local recurrence rates for HCC, colorectal cancer, and other metastatic lesions were 27.6 per cent, 29.1 per cent, and 52 per cent, respectively. The morbidity rate for the procedure was 11 per cent. There was one mortality (0.9%) related to RFA. Laparoscopic RFA for HCC in Childs-Pugh Class C cirrhotics (n = 6) resulted in 50 per cent of patients being transplanted with no evidence of disease at a mean follow-up period of 14 months. RFA is a safe and effective way for treating HCC and other unresectable tumors in the liver that are not eligible for hepatic resection. More effective control of systemic recurrence will dictate survival in the majority of patients with metastatic cancers. Local ablation for HCC in cirrhotic patients may be an effective bridge to transplantation. Liver transplantation may still be the most effective long-term treatment for localized HCC.

Brief communication: Glomerulonephritis in patients with hepatitis C cirrhosis undergoing liver transplantation.

BACKGROUND: Patients infected with hepatitis C virus (HCV) frequently develop renal failure after liver transplantation. OBJECTIVE: To describe renal histologic characteristics and concomitant clinical features in HCV-infected patients with end-stage cirrhosis. DESIGN: Case series. SETTING: Single-center liver transplant program in the United States. PATIENTS: 30 patients who received liver transplants for HCV-induced cirrhosis. INTERVENTION: Kidney biopsy during liver engraftment. MEASUREMENTS: Clinical data and laboratory tests of renal function within 6 months before liver transplantation. RESULTS: Twenty-five patients had immune-complex glomerulonephritis: membranoproliferative glomerulonephritis type 1 (n = 12), IgA nephropathy (n = 7), and mesangial glomerulonephritis (n = 6). Of these patients, 10 had normal serum creatinine levels, normal urinalysis results, and normal quantitative proteinuria. For 5 others, the only renal abnormality was an increased serum creatinine level. No patient had cryoglobulins in the blood or kidney. LIMITATIONS: This small observational study did not include patients with nonviral cirrhosis and did not document post-transplantation outcomes. CONCLUSIONS: Immune-complex glomerulonephritis was common in patients with end-stage HCV-induced cirrhosis and was often clinically silent. Its potential to cause renal failure after liver transplantation may be underappreciated.