This work presents the first application of high-resolution magic angle spinning (HR-MAS) 1H NMR spectroscopy to human liver biopsy samples, allowing a determination of their metabolic profiles before removal from donors, during cold perfusion, and after implantation into recipients. The assignment of peaks observed in the 1H HR-MAS NMR spectra was aided by the use of two-dimensional J-resolved, TOCSY and 1H-13C HMQC spectra. The spectra were dominated by resonances from triglycerides, phospholipids, and glycogen and from a variety of small molecules including glycerophosphocholine (GPC), glucose, lactate, creatine, acetate, amino acids, and nucleoside-related compounds such as uridine and adenosine. In agreement with histological data obtained on the same biopsies, two of the six livers were found to contain high amounts of triglycerides by NMR spectroscopy, which also indicated that these tissues contained a higher degree of unsaturated lipids and a lower proportion of phospholipids and low molecular weight compounds. Additionally, proton T2 relaxation times indicated two populations of lipids, a higher mobility triglyceride fraction and a lower mobility phospholipid fraction, the proportions of which changed according to the degree of fat content. GPC was found to decrease from the pretransplant to the posttransplant biopsy of all livers except for one with a histologically confirmed high lipid content, and this might represent a biomarker of liver function posttransplantation. NMR signals produced by the liver preservation solution were clearly detected in the cold perfusion stage biopsies of all livers but remained in the posttransplant spectra of only the two livers with a high lipid content and were prominent mainly in the graft that later developed primary graft dysfunction. This study has shown biochemical differences between livers used for transplants that can be related to the degree and type of lipid composition. This technology might therefore provide a novel screening approach for donor organ quality and a means to assess function in the recipient after transplantation.

AIMTo identify objective predictive factors for donor after cardiac death (DCD) graft loss and using those factors, develop a donor recipient stratification risk predictive model that could be used to calculate a DCD risk index (DCD-RI) to help in prospective decision making on organ use.METHODSThe model included objective data from a single institute DCD database (2005-2013, n = 261). Univariate survival analysis was followed by adjusted Cox-regressional hazard model. Covariates selected via univariate regression were added to the model via forward selection, significance level P = 0.3. The warm ischemic threshold was clinically set at 30 min. Points were given to each predictor in proportion to their hazard ratio. Using this model, the DCD-RI was calculated. The cohort was stratified to predict graft loss risk and respective graft survival calculated.RESULTSDCD graft survival predictors were primary indication for transplant (P = 0.066), retransplantation (P = 0.176), MELD > 25 (P = 0.05), cold ischemia > 10 h (P = 0.292) and donor hepatectomy time > 60 min (P = 0.028). According to the calculated DCD-RI score three risk classes could be defined of low (DCD-RI < 1), standard (DCD-RI 2-4) and high risk (DCD-RI > 5) with a 5 years graft survival of 86%, 78% and 34%, respectively.CONCLUSIONThe DCD-RI score independently predicted graft loss (P < 0.001) and the DCD-RI class predicted graft survival (P < 0.001).

A diaphragmatic hernia (DH) is a rare complication of pediatric liver transplantation (LT), with multiple factors implicated in the pathophysiology. It is a potentially life-threatening condition in the absence of early recognition and surgical treatment. A DH after LT has been reported in 16 patients in 7 case series. We report 10 cases from our institution and review the published literature to understand the underlying pathophysiology. The study sample included all children (<18 years of age) who underwent LT from October 1989 to August 2013 at our center and subsequently presented with a DH. Among 4433 LT procedures performed in this time period, 1032 were for children. Ten DH cases were recognized, and risk factors were assessed. The mean age at diagnosis was 4.9 years, all patients with a DH received left lateral segment split grafts, and the mean graft weight was 248 6 41 g with a mean graft-to-recipient body weight ratio (GBWR) of 3% 6 1.22% (range 5 1.7%-5.0%). The mean cold ischemia time was 510.7 6 307.6 minutes (range 5 60-900 minutes). Six patients had a primary abdominal muscle closure, 3 had a temporary Silastic mesh closure, and 1 had a skin closure only. Postoperative ascites and pleural effusion did not appear to be significant risk factors. All 10 children presented with a right posterolateral DH, with 1 also having a left DH. The small bowel was herniated in the majority. All patients underwent prompt surgical intervention without complications. An early age, a split graft, and a high GBWR may be risk factors for a DH. A high index of suspicion and prompt surgical intervention minimize complications.