1,721,063 research outputs found
Pilot, open, randomized, prospective trial for normothermic machine perfusion evaluation in liver transplantation from older donors.
No full textEx-situ normothermic machine perfusion (NMP) might minimize ischemia/reperfusion injury (IRI) of liver grafts. Twenty primary liver transplants recipients of older grafts (≥70 years) were randomized 1:1 to NMP or cold storage (CS). The primary study endpoint was to evaluate graft and patient survival at 6 months posttransplantation. The secondary endpoint was to evaluate: IRI by means of peak transaminases within 7 days after surgery; incidence of biliary complications at month 6, and evaluation of liver and bile duct biopsies. Liver and bile duct biopsies were collected at bench surgery, end of ex-situ NMP, and end of transplant surgery. Interleukin 6, 10 and TNF-α perfusate concentrations were tested during NMP. All grafts were successfully transplanted. Median (IQR) posttransplant AST peak was 709 (371-1575) and 574 (377-1162) UI/L, for NMP and CS respectively (p=0.597). One hepatic artery thrombosis in the NMP group and one death in the CS group were observed. In NMP, we observed high TNF-α perfusate levels and these were inversely correlated with lactate (p<0.001). Electron microscopy showed decreased mitochondrial volume density and steatosis, and increased volume density of autophagic vacuoles at the end of transplantation in NMP versus CS patients (p<0.001). Use of NMP with older liver grafts is associated with histological evidence of reduced ischemia/reperfusion injury, although the clinical benefit remains to be demonstrated. This article is protected by copyright. All rights reserved
Reply to "Association between donor age and risk of graft failure after liver transplantation: an analysis of the Eurotransplant database”
No full textReply to https://doi.org/10.1111/tri.1335
Donor diabetes and prolonged cold ischemia time increase the risk of graft failure after liver transplant: Should we need a redefinition of the donor risk index?
No full textDear Editors,
We read with great interest the paper by Brüggenwirth et al. (1) about the importance of cold ischemia time (CIT) and diabetes type II (DM-2) in increasing the risk of graft failure after liver transplantation (LT). The results obtained from the UNOS database are in line with those obtained in a recently published study coming from our center. (2) Our retrospective, single-center analysis was based on data from 1,354 adult LTs performed at the University of Pisa Medical School Hospital: in all the cases, whole sized livers coming from deceased-brain donors were transplanted. Using a propensity score approach, 448 patients receiving a graft younger than 70 years were finally matched with 515 counterparts receiving grafts older than 70 years. Four variables were found to be independently significant as risk factors for graft loss, namely HCV positivity (HR=2.1; p<0.001), donor age (HR=1.0; 95% p<0.001), CIT (HR=1.0; p=0.042), and donor DM-2 status (HR=1.5; p=0.047). It is extremely interesting to underline that two apparently very different databases like a North American and an Italian one consented to obtain similar results, mainly in consideration of their big numerosity (58,226 and 1,354 respectively). In both the contexts, the synergic action of acute (prolonged CIT) and chronic (DM-2) damages eventually ended in promoting post-LT graft failure. Indeed, the fact that advanced donor age is an amplifying factor of chronic damages induced by DM-2 looks to be as a natural consequence. Also Brüggenwirth et al. reported that “the only risk factor that meaningfully altered the HR for DM-2 (and remained statistically significant) in the final models was donor age”.(1) Here comes the problem connected with the vagueness of the definition of donor DM-2. In fact, defining DM-2 status as “use of insulin” or “altered blood sugar levels” is not enough for completely capturing the real pathological changes induced by the disease. For example, using these dichotomous variables completely fails in defining the length and the severity of DM-2: thus, age is probably only a very good surrogate for this purpose. For this reason, identification of pathological markers (3) consenting to pre-operatively define the grafts at high-risk for poor post-LT function should represent a real revolution in the selection and allocation processes. We strongly believe that not age per se, but a combination of acute and chronic damages associated with age, mainly due to metabolic diseases, play a fundamental role in worsening results when using older grafts.
Under the light of these experiences, and in agreement with other Authors,(4) a re-evaluation of the Donor Risk Index (DRI) should be considered. In fact, after the publication by Feng et al. in 2006,(5) a larger use of the so called extended criteria donors has been observed, in particular of donors with multiple comorbidities. As a consequence, a new analysis able to update the donor-related risk stratification should be considered. We believe that a new universal DRI should be the future target, including international experiences, and not being limited only to regional databases which may not be able to intercept specific behaviors or needs of a particular region of the world
VIABILITY TESTING DURING NORMOTHERMIC MACHINE PERFUSION REQUIRES BOTH HEPATOCELLULAR AND CHOLANGIOCELLULAR CRITERIA
No full textAge disparities in transplantation
No full textPurpose of review: The aim of this review is to outline disparities in liver and kidney transplantation across age spectrum. Disparities do not involve only recipients whose age may severely affect the possibility to access to a potentially life-saving procedure, but donors as well. The attitude of transplant centers to use older donors reflects on waiting list mortality and drop-out. This review examines which age categories are currently harmed and how different allocation systems may minimize disparities.
Recent findings: Specific age categories suffer disparities in the access to transplantation. A better understanding of how properly evaluate graft quality, a continuous re-evaluation of the most favorable donor-to-recipient match and most equitable allocation system are the three key points to promote 'justice and equality' among transplant recipients.
Summary: The duty to protect younger patients waiting for transplantation and the request of older patients to have access to potentially life-saving treatment urge the transplant community to use older organs thus increasing the number of available grafts, to evaluate new allocation systems with the aim to maximize 'utility' while respecting 'equity' and to avoid 'futility' thus minimizing waiting list mortality and drop-out, and improving the survival benefits for all patients requiring a transplant
Analysis of patients' needs after liver transplantation in Tuscany: a prevalence study.
Full text linkBACKGROUND: The reorganization of the healthcare system in Tuscany aims at characterizing the hospitals as a place for the treatment of acute patients. This event, together with the improvement of long-term survival after orthotopic liver transplantation (OLT), calls for a management network able to ensure effective continuity of care for patient needs in the posttransplantation period.
MATERIALS AND METHODS: An observational study of prevalence has been carried out with the primary objective to evaluate patients' needs and criticalities both in routine daily life and in urgency in the posttransplantation period and the capacity of the regional health system to support them. A survey, using a semi-structured questionnaire consisting of 27 questions, was administered to all patients resident in Tuscany who underwent transplantation from 2000 to 2010. The survey tool assessed the following: socio-demographic data, personal, family and social difficulties, problems emerged in the clinical routine and urgency, resolution modality, relationships with the general practitioner and the referral specialist, and services the patients would appreciate receiving in their province of residence.
RESULTS: In the study, 346 patients matched the inclusion criteria of the study, 324 gave telephone consent to participate in the survey, and 225 responded (69.4%). The most frequent difficulties were as follows: depression (39.5%), difficulty in returning to work (29.3%), low income (22.6%), lack of self-sufficiency (22.6%), addictions (19.1%) (cigarette smoking 16.4%), 12.4% eating disorders, and 18.9% other difficulties (social isolation, absence of a family network, and so on). The main reasons for dissatisfaction were as follows: difficulty to obtain the required laboratory tests and lack of a reference structure at the local health facility. Few patients have a referral specialists in their area and most of them primarily refer to the Transplant Center even late after the procedure.
DISCUSSION: Early diagnosis of specific conditions (depression, addiction, and eating disorders) should be implemented in the follow-up period and services such as counselling, dietary support, rehabilitation, and social services should be provided locally. An integrated management system between the transplantation center and the local facilities (hospitals, general practitioners, primary care, and laboratories) should be implemented and referral specialized centers should be identified locally
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
TRAPIANTO DI FEGATO CON GRAFT MARGINALE CONSERVATO CON MACCHINA DA PERFUSIONE NORMOTERMICA: PRIMO CASO ITALIANO
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
