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Background Arteriovenous fistulas are critical for haemodialysis, but maturation rates remain poor. Experimental and anecdotal evidence has supported the use of transdermal glyceryl trinitrate ( GTN) patches. The aim of this RCT was to determine whether use of a GTN patch aids arteriovenous fistula maturation. Methods Patients referred for arteriovenous fistula formation were eligible. The GTN or placebo patch was applied immediately after surgery and left in situ for 24 h. The primary outcome measure was the change in venous diameter at 6 weeks after fistula formation. The secondary outcome measure was clinical fistula patency at 6 weeks. Results Of 200 patients recruited (533 screened), 101 were randomized to the placebo group and 99 to the GTN group. Of these, 81 and 86 respectively completed surgery, and had follow-up data available at 6 weeks. Improvements in venous diameter were similar in the two groups: mean(s.d.) increase 2·3(1·9) mm in the placebo group compared with 2·2(1·8) mm in the GTN group ( P = 0·704). The fistula failure rate did not differ significantly between the two groups: 23 per cent for placebo and 28 per cent for GTN ( P = 0·596). Conclusion GTN transdermal patches used for 24 h after surgery did not improve arteriovenous fistula maturation. Registration number: NCT01685710 (). [ABSTRACT FROM AUTHOR]

Introduction: Hypothermic machine perfusion, an organ preservation modality, involves flow of chilled preservation fluid through an allograft's vasculature. This study describes a simple, reproducible, human model that allows for interrogation of flow effects during ex vivo organ perfusion., Materials and Methods: Gonadal veins from deceased human renal allografts were subjected to either static cold storage or hypothermic machine perfusion for up to 24 hours. Caspase-3, Krüppel-like factor 2 expression and electron microscopic analysis were compared between 'flow' and 'no-flow' conditions, with living donor gonadal vein sections serving as negative controls., Results: The increase in caspase-3 expression was less pronounced for hypothermic machine-perfused veins compared with static cold storage (median-fold increase 1.2 vs 2.3; P < 0.05). Transmission electron microscopy provided ultrastructural corroboration of endothelial cell apoptosis in static cold storage conditions. For static cold storage preserved veins, Krüppel-like factor 2 expression diminished in a time-dependent manner between baseline and 12 hours ( P < 0.05) but was abrogated and reversed by hypothermic machine perfusion ( P < 0.05)., Conclusions: Our methodology is a simple, reproducible and successful model of ex vivo perfusion in the context of human organ preservation. To demonstrate the model's utility, we establish that two widely used markers of endothelial health (caspase-3 and Krüppel-like factor 2) differ between the flow and no-flow conditions of the two predominant kidney preservation modalities. These findings suggest that ex vivo perfusion may mediate the induction of a biochemically favourable endothelial niche which may contribute tohypothermic machine perfusion's association with improved renal transplantation outcomes.

Conflicting evidence surrounds clinical outcomes in obese individuals after transplantation; nonetheless, many are denied the opportunity to receive a transplant. Allografts with complex vascular anatomy are regularly used in both deceased and living donor settings. We established the risk of transplanting kidneys with multiple renal arteries into obese recipients. A retrospective analysis of data from 1095 patients undergoing renal transplantation between January 2004 and July 2013 at a single centre was conducted. Of these, 24.2% were obese (body mass index >30 kg/m(2)), whereas 25.1% of kidneys transplanted had multiple arteries, thereby making the transplantation of kidneys of complex anatomy into obese recipients a relatively common clinical occurrence. Vessel multiplicity was associated with inferior 1-year graft survival (85.8.% vs 92.1%, P = .004). Obese patients had worse 1-graft survival compared to those of normal BMI (86.8% vs 93.8%, P = .001). The risk of vascular complications and of graft loss within a year after transplantation were greater when grafts with multiple arteries were transplanted into obese recipients as compared to their nonobese counterparts (RR 2.00, CI 95% 1.07-3.65, and RR 1.95, CI 95% 1.02-3.65). Additionally, obese patients faced significantly higher risk of graft loss if receiving a kidney with multiple arteries compared to one of normal anatomy (RR 1.97, 95% CI 1.02-3.72). Thus, obese patients receiving complex anatomy kidneys face poorer outcomes, which should be considered when allocating organs, seeking consent, and arranging for aftercare., (Copyright © 2015 Elsevier Inc. All rights reserved.)