The influence of pallets on the behaviour and design of drive-in steel storage racks - Part I: Behaviour

Drive-in steel storage racks represent a popular alternative to the more common selective racks when available space is restricted or when storing the same good. In drive-in racks, the forklift truck drives into the rack and stores the pallets on beam rails on the first-in last-out principle. Recent experimental studies have shown that by acting as horizontal ties between uprights, pallets significantly influence the structural behaviour of the rack. However, due to the uncertainty in the degree of friction between the rail beams and the pallets, current industry design practice does not consider this effect. This paper quantifies the influence of the pallets on the bending moment distribution in the uprights using a 3D finite element model calibrated against experimental results on a full scale drive-in rack. Additionally, as 3D models may be computationally intensive when a large number of analyses are required, this paper presents an improved version of the 2D model of drive-in racks introduced by Godley. In the improved 2D model, all possible loading scenarios and the influence of pallets on the structural behaviour of the rack are considered. When compared to advanced 3D finite element analyses, the model is able to accurately reproduce the bending moment distribution in the upright, with and without the presence of pallets

The influence of pallets on the behaviour and design of steel drive-in storage racks - Part II Design

This paper analyses the influence of the horizontal restraints provided by pallets on the ultimate capacity of drive-in racks. The paper is based on the assumption that one can accurately determine the coefficient of friction between the rail beams and the pallets or can design a device that restrains the pallets from sliding on the rail beams. Thirty-six drive-in racks representing the global sale of an Australian manufacturer over three years are analysed for all possible loading scenarios. For the sake of computational efficiency, the simple 2D model introduced in the companion paper is used for the study. The load case(s) governing the structural design is(are) also clarified and the friction coefficient or strength of a restraining device required to prevent the pallets from sliding is determined

Valeur pronostique de l’index de résistance lors de la conservation rénale pulsatile hypothermique des greffons prélevés à partir de donneurs décédés après arrêt cardiaque

International audienceObjectifsLa pénurie d’organe a conduit à utiliser des reins de plus en plus marginaux comme ceux issus des Donneurs Décédés par Arrêt Cardiaque (DDAC). L’évaluation de ces greffons est basée sur l’analyse des caractéristiques du donneur et des paramètres de perfusion. Le but de notre étude est de vérifier l’intérêt de l’utilisation de l’Index de Résistance (IR) pour l’évaluation de la viabilité des greffons.MéthodesDepuis 2006, 54 greffons ont été prélevés puis perfusés par la machine RM3 (Waters Medical®). Les donneurs respectaient les critères du protocole national de DDAC. Les greffons étaient perfusés avant extraction par sonde de Gillot (SG) ou par Circulation Régionale Normothermique (CRN). Une bi-greffe était réalisée si les IR étaient compris entre 0,35 et 0,5 mmHg/ml/min. Une étude que nous avons publiée montrait des résultats fonctionnels similaires entre des bi-greffes réalisées avec un IR compris entre 0,35 et 0,5 et des mono-greffes. Nous avons étudié le rôle des IR par rapport aux caractéristiques des donneurs et aux résultats fonctionnels post-transplantation.RésultatsEntre 2006 et 2013, 46 patients ont été transplantés à partir de DDAC. Huit greffons n’ont pas été transplantés du fait de mauvais paramètres de perfusion (IR > 0,40 mmHg/ml/min). Six patients ont eu une bi-greffe. Dix-sept greffes ont été réalisées après CRN et 29 après SG. Le suivi médian a été de 59,7 ± 34,6 mois. Il n’y a eu aucune Non Fonction Primaire (NFP). 86,9 % des patients ont eu une Reprise Retardée de Fonction. La clairance calculée moyenne à 12 mois est de 41,5 ml/min/1,73m2. Les IR des greffons conservés par Gillot ou par CRN étaient statistiquement différents. Le sexe, le taux de créatinine du donneur, les temps d’ischémie chaude, de low-flow, et les durées entre le début de CRN ou GILLOT et le prélèvement impactaient significativement sur les IR.ConclusionL’absence de NFP et les bons résultats fonctionnels permettent de valider notre stratégie d’acceptation des greffons en fonction de l’analyse des IR. Les IR sont corrélés au degré d’agression tissulaire subi par le greffon pendant la phase critique de l’arrêt cardiocirculatoire au prélèvement

Transplantation rénale pédiatrique

International audienceAIMS:To describe indications, surgical aspects, results and outcomes of kidney transplantation in children.MATERIAL AND METHODS:An exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords (MESH): "kidney transplantation", "pediatric", "children", "outcomes". Publications obtained were selected based on methodology, language, date of publication (last 10 years) and relevance. Prospective and retrospective studies, in English or French, review articles; meta-analysis and guidelines were selected and analyzed. This search found 2608 articles. After reading titles and abstracts, 18 were included in the text based on their relevance.RESULTS:Kidney transplantation is the gold-standard treatment for end stage renal kidney disease in children. The surgical procedure is well standardized with a retroperitoneal approach when child and kidney size allow it or a transperitoneal approach in child less than 15 kg and big size kidney graft. Anastomosis sites include iliac vessels in the retroperitoneal approach, and inferior vena cava and aorta in case of transperitoneal procedure. Ureteral reimplantation used most of the time a Campos Freire technique. Sometimes, particular conditions in the recipient (such as vena cava thrombosis) required procedure adaptation.CONCLUSION:Graft survival dramatically increased over the past few years and is now superior to those observed in adult kidney transplantation, particularly in experienced team with microsurgery skills. Immunosuppressive treatments are similar to adults. Viral infections and post-transplant lymphoproliferative disorder are the main complications of renal transplantation in children and may lead to lethal outcomes. An increase graft loss is observed during boyhood due to immunosuppressive drugs uncompliance

Endopyelotomie pour syndrome de la jonction sur rein greffe A propos de trois observations

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Influence of allograft weight to recipient bodyweight ratio on outcome of cadaveric renal transplantation

AIM: One of the factors that may affect survival and function of kidney graft is its functional mass. METHODS: In a prospective study, we investigated the impact of the ratio between donor kidney weight in grams and recipient bodyweight in kilograms (DKW/RBW) on creatinine clearance, inulin clearance, and proteinuria: 154 kidneys from deceased donors were weighed and the mean kidney weight was 227 ± 59 g, the bodyweight of the recipients was 64 ± 19 kg. RESULTS: This study showed significant lower values of modification of diet in renal disease (MDRD) in patients with DKW/RBW ratio 2.5 g/kg and between 2.5 and 4.5 g/kg compared with those with DKW/RBW ratio >4.5 g/kg as well as in patients with DKW/RBW ratio 4 g/kg; moreover a random coefficient model showed a different time evolution in creatinine clearance values in patients with DKW/RBW ≤ 3 g/kg when compared with patients with DKW/RBW ratio >4 g/kg. There were significant lower values of inulin clearance in patients with DKW/RBW ratio between 2.5 and 4.5 g/kg compared with those with DKW/RBW ratio >4.5 g/kg at 12 post-transplant months and a significantly greater occurrence and earlier appearance of proteinuria in the recipients with DKW/RBW ratio <2.5 g/kg. DKW/RBW ratio did not influence DGF incidence and graft survival. Donor and recipient gender, number of acute rejection episodes and donor age also significantly influenced MDRD values. CONCLUSIONS: Measurements of graft weight as well as donor kidney and recipient body matching should be recommended as influencing renal function

Ischémie–reperfusion. Liquides de conservation et machines de perfusion en transplantation rénale.

Cet article fait partie intégrante du rapport « Les urologues et la transplantation rénale » du 110e Congrès de l’Association française d’urologie rédigé sous la direction de François Kleinclauss.International audienceAimsTo describe ischemia–reperfusion mechanisms, the impact on kidney graft and strategies developed to minimize ischemia–reperfusion damages.Material and methodsAn exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords: ischemia-reperfusion; organ preservation; hypothermic machine perfusion; renal transplantation. Publications obtained were selected based on methodology, language, date of publication and relevance. Prospective and retrospective studies, in English or French, review articles; meta-analysis and guidelines were selected and analyzed. This search found 1293 articles. After reading titles and abstracts, 88 were included in the text, based on their relevance.ResultsIschemia–reperfusion injuries occur when blood supply of an organ is interrupted or drastically reduced. Ischemic damages started immediately after arterial clamping in donor, persist during cold ischemia time, and are increased after reperfusion because of increased oxygen levels, organ warming and recipient cell infiltration. Besides metabolic and biologic impact, IR induced dramatic immunologic impact through immunologic cells activation.ConclusionsKnowledge of IR mechanisms is crucial to improve organ storage strategies and to decreased impact of IR on long-term graft and patient survival. Hypothermic machine perfusion was associated with prolonged graft survival versus cold storage. Principles and results of hypothermic machine perfusion will be reported.ObjectifDécrire le mécanisme d’ischémie–reperfusion, ses conséquences sur le transplant rénal et les stratégies de conservation permettant de réduire les lésions d’ischémie–reperfusion.Matériel et méthodesUne recherche bibliographique exhaustive à partir de Medline (http://www.ncbi.nlm.nih.gov) et Embase (http://www.embase.com) a été réalisée en utilisant les mots clés suivants seuls ou en combinaison : « insuffisance rénale, transplantation rénale, lésions d’ischémie–reperfusion, préservation d’organe, machines de perfusion et cellules endothéliales ». Les articles obtenus ont ensuite été sélectionnés sur leur méthodologie, leur langue de publication (anglais/français), leur pertinence par rapport au sujet traité et leur date de publication. Seules les études prospectives et rétrospectives en anglais et en français, articles de revue, de méta-analyse ou de recommandations ont été sélectionnés (1293 articles). Après sélection en fonction du titre et du résumé et de la pertinence, 88 articles ont été analysés et inclus dans les différentes sous sections (ischémie–reperfusion 61 articles ; conservation d’organe 27 articles).RésultatsLes lésions d’ischémie débutent lors du clampage de l’organe chez le donneur et perdurent jusqu’au déclampage. Les lésions de reperfusion correspondent à une aggravation des lésions précédentes lors de la phase initiale de reperfusion, conséquence de l’apport d’oxygène alors que le métabolisme mitochondrial n’est pas restauré, du réchauffement et de l’infiltration du greffon par les cellules du receveur. Outre d’importantes conséquences métaboliques et structurelles, ces lésions ont des conséquences immunologiques majeures, notamment par le biais de l’activation de l’immunité innée.ConclusionLa compréhension des mécanismes d’ischémie–reperfusion est essentielle pour améliorer les techniques de préservation et limiter leur conséquence à long terme sur la survie des greffons et des patients. Parmi les stratégies pour lutter contre les lésions d’ischémie–reperfusion, la conservation des greffons sur machine à perfusion a montré son avantage tant sur la plan biologique que clinique. Les principes et les résultats de la perfusion des greffons seront décrits dans cet article

Dual kidney transplantation from uncontrolled deceased donors after cardiac arrest: a possible option

Organ shortage is a major problem in organ transplantation. For this reason, transplantation teams have found it necessary to revisit their organ acceptance criteria. Uncontrolled deceased donors after cardiac arrest could increase the donor pool by 20%, but at the same time there is a greater risk of delayed graft function and primary non-function. Dual kidney transplantation is an option when single kidney transplantation cannot be carried out because of lack of organ quality. We report for the first time our four first dual kidney transplantation from uncontrolled deceased donors after cardiac arrest with a follow up longer than 1 year. We described graft outcomes until 5 years, and histology at 3 and 12 months after transplantation. All organs were machine perfused in order to assess their quality leading to a single kidney transplantation or dual kidney transplantation decision. After 1 year of follow up, all grafts were functional with a mean estimated glomerular filtration rate of 44.5 ± 3.3 mL/min/1.73 m2, and a mean inulin clearance of 43.7 ± 13.6 mL/mn/1.73 m2. These findings suggest that dual kidney transplantation can represent a viable option for kidneys unsuitable for single kidney transplantation without increasing the rate of surgical complications. Successful transplantation is linked to histological, biological and donor clinical criteria, as well as perfusion parameters

Recommandations françaises du Comité de transplantation de l’association française d’urologie (CTAFU) : agents antiplaquettaires et anticoagulants oraux directs en transplantation rénale

International audienceObjective: To define guidelines for the use of antiplatelet therapy (AT) and direct oral anticoagulants (DOAC) in candidates for kidney allotransplantation.Method: A review of the medical literature following a systematic approach was conducted by the CTAFU to report the use of AT and DOAC before major surgery and in the setting of advanced chronic kidney disease, defining their managment prior to kidney transplantation with the corresponding level of evidence.Results: DOAC are not recommended in patients under dialysis. Aspirin therapy, but not anti-P2Y12 and DOAC, may be maintained during renal transplantation. Anti-P2Y12 and DOAC should not be use in patients awaiting a kidney transplant, except when a living donor is scheduled, therefore authorizing treatment interruption in optimal conditions. Further data regarding DOAC reversion and monitoring may improve their use in this setting. Global level of evidence is weak.Conclusion: These French recommendations should contribute to improve surgical management of kidney transplant candidates exposed to AT or DOA