The Use of 2-Octylcyanoacrylate Dressing in Reducing the Risk of Superficial Surgical Site Infections in Colorectal Stoma Surgery: A Retrospective Cohort Study.

BACKGROUND: Superficial surgical site infection (SSI) is a common morbidity following bowel resection surgery involving stoma formation with clinical and financial implications. The study aimed to evaluate the role of topical skin adhesive, 2-octylcyanoacrylate (Dermabond®) (2-OCA) in reducing wound infections following colorectal stoma surgery. METHODS: We performed a retrospective, single-centre, cohort study using clinical notes. All patients, over the age of 18, undergoing bowel resection either elective or emergency, with stoma formation over five years from January 2015 to December 2019 were included. The primary endpoint was SSI, defined by the clinical manifestation of inflammation including pain, erythema, and discharge, regardless of the microbiological culture results. Patients received either 2-OCA glue as wound dressing or standard firm adhesive wound dressing e.g. Opsite. RESULTS:  Overall, 604 patients were included in the study. The median age was 67; 187 (31%) patients received Dermabond (Group 1) and 417 (69%) received standard care (Group 2). A total of 288 (47%) patients were female, 134 (22%) had body mass index (BMI) greater than 30, 87 (14%) were diabetic, and 90 (15%) were smokers. A total of 279 (46%) patients had an American Society of Anesthesiologists (ASA) score of 3 and 4; 282 (47%) patients went through emergency surgery, 279 (64%) patients underwent dirty surgery, and 220 (35%) patients developed SSI. BMI greater than 30 compared to < 30 (OR: 2.32, 95% CI: 1.54-3.49, p<0.0001), diabetes compared to no diabetes (OR: 0.54, 95% CI: 0.32-0.92, p<0.0241), dirty surgery compared to clean surgery (OR: 2.26, 95% CI: 1.51-3.37, p<0.0001) and standard care, no 2-OCA glue use compared to the use of 2-OCA glue (OR: 1.52, 95% CI: 1.03-2.24, p=0.0343) were associated with SSIs.  Conclusion: Our study demonstrates that there is an association between 2-OCA and reduced SSIs in bowel resection surgery involving stoma formation when compared to standard methods of wound dressing. Further randomised clinical trials are recommended to strengthen this evidence and demonstrate causation.

Cardiorespiratory Optimisation By Arteriovenous fistula Ligation after renal Transplantation (COBALT): study protocol for a multicentre randomised interventional feasibility trial.

INTRODUCTION: Cardiovascular events are a major cause of mortality following successful kidney transplantation.Arteriovenous fistulas (AVFs) are considered the best option for haemodialysis, but may contribute to this excess mortality because they promote adverse cardiac remodelling and ventricular hypertrophy. This raises the question whether recipients with a well-functioning kidney transplant should undergo elective AVF ligation. METHODS AND ANALYSIS: The COBALT feasibility study is a multicentre interventional randomised controlled trial (RCT) that will randomise renal transplant patients with stable graft function and a working AVF on a 1:1 basis to standard care (continued conservative management) or to AVF ligation. All patients will perform cardiopulmonary exercise testing (CPET) on recruitment and 6 months later. Daily functioning and quality of life will be additionally assessed by questionnaire completion and objective measure of physical activity. The primary outcome-the proportion of approached patients who complete the study (incorporating rates of consent, receipt of allocated intervention and completion of both CPETs without withdrawal)-will determine progression to a full-scale RCT. Design of the proposed RCT will be informed by an embedded qualitative assessment of participant and healthcare professional involvement. ETHICS AND DISSEMINATION: This study has been approved by the East Midlands-Derby Research Ethics Committee (22/EM/0002) and the Health Research Authority. The results of this work will be disseminated academically through presentation at national and international renal meetings and via open access, peer-reviewed outputs. Existing networks of renal patient groups will also be used to disseminate the study findings to other key stakeholders. TRIAL REGISTRATION NUMBER: ISRCTN49033491.

A systematic review of living kidney donor enhanced recovery after surgery.

Enhanced recovery after surgery (ERAS) reduces complications and shortens hospital stay without increasing readmission or mortality. However, its role in living donor nephrectomy (LDN) has not yet been defined. Medline, Embase, CINAHL, PsycINFO, and Cochrane Central were searched prior to 08/01/21 for all randomized controlled and cohort studies comparing ERAS to standard of care in LDN. The study was registered on PROSPERO (CRD: CRD42019141706). One thousand, three hundred seventy-seven patients were identified from 14 studies (698 patients with ERAS and 679 patients without). There were considerable differences in the protocols used, and compliance with general ERAS recommendations was poor. Meta-analysis of laparoscopic procedures (including hand- and robot-assisted) revealed that duration of stay was significantly reduced by 0.98 days with ERAS (95% CI = 0.36-1.60, P = .002) and opiate requirement by 32.4 mg (95% CI = 1.1-63.7, P = .04). There was no significant difference n readmission rates or complications. Quality of evidence was low to moderate assessed using the GRADE tool. This review suggests there is a positive benefit of ERAS in laparoscopic LDN. However, there was considerable variation in ERAS protocols used, and the quality of evidence was low; as such, a guideline for ERAS in LDN should be developed and validated.

Mitochondria as Therapeutic Targets in Transplantation.

Advances in surgical procedures, technology, and immune suppression have transformed organ transplantation. However, the metabolic changes that occur during organ retrieval, storage, and implantation have been relatively neglected since the developments many decades ago of cold storage organ preservation solutions. In this review we discuss how the metabolic changes that occur within the organ during transplantation, particularly those associated with mitochondria, may contribute to the outcome. We show how a better understanding of these processes can lead to changes in surgical practice and the development of new drug classes to improve the function and longevity of transplanted grafts, while increasing the pool of organs available for transplantation.

Renal transplantation during the SARS-CoV-2 pandemic in the UK: Experience from a large-volume center.

There is uncertainty about the safety of kidney transplantation during the SARS-CoV-2 pandemic due to the risk of donor transmission, nosocomial infection and immunosuppression use. We describe organ donation and transplant practice in the UK and assess whether kidney transplantation conferred a substantial risk of harm. Data from the UK transplant registry were used to describe kidney donation and transplant activity in the UK, and a detailed analysis of short-term, single-center, patient results in two periods: during the pre-pandemic era from 30th December 2019 to 8th March 2020 ("Pre-COVID era") and the 9th March 2020 to 19th May 2020 ("COVID era"). Donor and recipient numbers fell by more than half in the COVID compared to the pre-COVID era in the UK, but there were more kidney transplants performed in our center (42 vs. 29 COVID vs. pre-COVID respectively). Overall outcomes, including re-operation, delayed graft function, primary non-function, acute rejection, length of stay and graft survival were similar between COVID and pre-COVID era. 6/71 patients became infected with SARS-CoV-2 but all were discharged without critical care requirement. Transplant outcomes have remained similar within the COVID period and no serious sequelae of SARS-CoV-2 infection were observed in the peri-transplant period.

Utilization and Outcomes of Single and Dual Kidney Transplants from Older Deceased Donors in the United Kingdom.

BACKGROUND AND OBJECTIVES: Kidneys from elderly deceased donors are often discarded after procurement if the expected outcomes from single kidney transplantation are considered unacceptable. An alternative is to consider them for dual kidney transplantation. We aimed to examine the utilization of kidneys from donors aged ≥60 years in the United Kingdom and compare clinical outcomes of dual versus single kidney transplant recipients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Data from the United Kingdom Transplant Registry from 2005 to 2017 were analyzed. We examined utilization rates of kidneys retrieved from deceased donors aged ≥60 years, and 5-year patient and death-censored graft survival of recipients of dual and single kidney transplants. Secondary outcomes included eGFR. Multivariable analyses and propensity score analysis were used to correct for differences between the groups. RESULTS: During the study period, 7841 kidneys were procured from deceased donors aged ≥60 years, of which 1338 (17%) were discarded; 356 dual and 5032 single kidneys were transplanted. Donors of dual transplants were older (median, 73 versus 66 years; P<0.001) and had higher United States Kidney Donor Risk Indices (2.48 versus 1.98; P<0.001). Recipients of dual transplants were also older (64 versus 61 years; P<0.001) and had less favorable human leukocyte antigen matching (P<0.001). After adjusting for confounders, dual and single transplants had similar 5-year graft survival (hazard ratio, 0.81; 95% CI, 0.59 to 1.12). No difference in patient survival was demonstrated. Similar findings were observed in a matched cohort with a propensity score analysis method. Median 12-month eGFR was significantly higher in the dual kidney transplant group (40 versus 36 ml/min per 1.73 m2; P<0.001). CONCLUSIONS: Recipients of kidneys from donors aged ≥60 years have similar 5-year graft survival and better graft function at 12 months with dual compared with single deceased donor kidney transplants.

Kidney transplantation following uncontrolled donation after circulatory death.

PURPOSE OF REVIEW: The identification and utilization of kidneys from uncontrolled donation after circulatory death (uDCD) donors for transplantation may increase transplantation rates markedly. This article summarizes the latest international results from successful uDCD kidney transplant programmes and considers how such programmes may impact on the transplant waiting list. RECENT FINDINGS: The results of more than 1000 uDCD donor kidney transplants have been reported since 2007 from France and Spain. Estimates from France, Spain and Sweden suggest that effective utilization of the potential uDCD donor pool might increase donation rates by 25%. The main concern relating to uDCD kidney transplantation is the high incidence of primary nonfunction with the incidence of primary nonfunction reported as 7-8% even with careful donor selection and the use of normothermic regional perfusion at the time of organ recovery. Notwithstanding, reported 1- year graft survival figures are equivalent to those from expanded criteria donors (ECD) and 10-year graft survival of between 72 and 82% was reported in the two single-centre series with longest reported follow-up period. SUMMARY: Uncontrolled DCD kidney transplantation has been successfully implemented in several regions in France and Spain. Wider implementation of uDCD programmes would increase substantially the number of kidneys for transplantation, while maintaining acceptable transplant outcomes.

Development of an objective, standardized tool for surgical assessment of deceased donor kidneys: The Cambridge Kidney Assessment Tool.

Quality assessment in kidney transplantation involves inspection to identify negative markers of organ quality. However, there is a paucity of evidence guiding surgical appraisal, and currently there is no evidence to differentiate important features from those that can be safely ignored. We propose a method to standardize surgical assessment and derived a simple rule to rapidly identify kidneys suitable for transplantation. Donor and recipient data were recorded alongside clinical outcomes in a prospectively maintained database. We developed a proforma (Cambridge Kidney Assessment Tool, CKAT) and used it to assess deceased donor kidney transplants. Factors predictive of utilization were identified by multivariate and univariate logistic regression analysis of CKAT-assessment scores, and test performance was evaluated using standard 2 × 2 contingency tables. Ninety-seven kidneys were included at a single center (2013-2014), and 184 CKAT assessments were performed. A CKAT threshold of "Carrell + Perfusion >3" was highly specific (99%) and performed favorably to consultant opinion (specificity 95%). 96% of the kidneys implanted in accordance with the rule survived to 1 year (mean eGFR 45.3 mL/min/1.73 m2 ). To our knowledge, this is the first attempt to objectively define macroscopic features that are relevant to kidney utilization. Common language could support training in organ assessment and ultimately help address unnecessary discard of donor kidneys.

Cold Pulsatile Machine Perfusion Versus Static Cold Storage for Kidneys Donated After Circulatory Death: A Multicenter Randomized Controlled Trial.

BACKGROUND: The benefits of cold pulsatile machine perfusion (MP) for the storage and transportation of kidneys donated after circulatory death are disputed. We conducted a UK-based multicenter, randomized controlled trial to compare outcomes of kidneys stored with MP versus static cold storage (CS). METHODS: Fifty-one pairs of kidneys donated after circulatory death were randomly allocated to receive static CS or cold pulsatile MP. The primary endpoint, delayed graft function, was analyzed by "intention-to-treat" evaluation. RESULTS: There was no difference in the incidence of delayed graft function between CS and MP (32/51 (62.8%) and 30/51 (58.8%) P = 0.69, respectively), although the trial stopped early due to difficulty with recruitment. There was no difference in the incidence of acute rejection, or in graft or patient survival between the CS and MP groups. Median estimated glomerular filtration rate at 3 months following transplantation was significantly lower in the CS group compared with MP (CS 34 mL/min IQR 26-44 vs MP 45 mL/min IQR 36-60, P = 0.006), although there was no significant difference in estimated glomerular filtration rate between CS and MP at 12 months posttransplant. CONCLUSIONS: This study is underpowered, which limits definitive conclusions about the use of MP, as an alternative to static CS. It did not demonstrate that the use of MP reduces the incidence of delayed graft function in donation after circulatory death kidney transplantation.

Surveillance arterioveNous fistulAs using ultRasound (SONAR) trial in haemodialysis patients: a study protocol for a multicentre observational study.

INTRODUCTION: Arteriovenous fistulas (AVFs) are considered the best and safest modality for providing haemodialysis in patients with end-stage renal disease. Only 20% of UK centres achieve the recommended 80% target for achieving dialysis of the prevalent dialysis population via permanent access (as opposed to a central venous catheter). This is partly due to the relatively poor maturation rate of newly created fistulas, with as many as 50% of fistulas failing to mature.The Surveillance Of arterioveNous fistulAe using ultRasound study will examine whether a protocolised programme of Doppler ultrasound (US) surveillance can identify, early after creation, potentially correctable problems in those AVFs that subsequently fail to mature. METHODS AND ANALYSIS: This is a multicentre observational study that will assess newly created AVFs by Doppler US performed at 2, 4, 6 and 10 weeks after creation. The primary outcome measure will be primary fistula patency at week 10. Secondary outcome measures include: successful use of the fistula; clinical suitability for dialysis; creation of new fistula or radiological salvage; fistula thrombosis; secondary fistula patency rate and patient acceptability. ETHICS AND DISSEMINATION: The study has been approved by the Cambridgeshire and Hertfordshire Research Ethics Committee and by the Health Research Authority (REC 18/EE/0234). The results generated from this work will be published as open access, within 3 years of trial commencement. We will also present our findings at key national/international renal meetings, as well as support volunteers at renal patient groups to disseminate the trial outcome. TRIAL REGISTRATION NUMBER: ISRCTN36033877.

Uncontrolled DCD donation-tilting at windmills or pushing against an open door?

Wider use of donation after circulatory death donors may increase transplant numbers substantially. Most countries that have adopted donation after circulatory death donation have focused on controlled donation after circulatory death donors, whereby life-supporting treatment is withdrawn in a coordinated manner. In this issue, del Río and colleagues report the Spanish experience for kidneys transplanted from uncontrolled donation after circulatory death donors (typically individuals with sudden cardiorespiratory arrest in the community). In the largest series to date, they confirm that remarkably good transplant outcomes are achievable.

PreImplantation Trial of Histopathology In renal Allografts (PITHIA): a stepped-wedge cluster randomised controlled trial protocol.

INTRODUCTION: Most potential kidney transplant donors in the UK are aged over 60 years, yet increasing donor age is associated with poorer graft survival and function. Urgent preimplantation kidney biopsy can identify chronic injury, and may aid selection of better 'quality' kidneys from this group. However, the impact of biopsy on transplant numbers remains unproven. The PreImplantation Trial of Histopathology In renal Allografts (PITHIA) study will assess whether the introduction of a national, 24 hours, digital histopathology service increases the number, and improves outcomes, of kidneys transplanted in the UK from older deceased donors. METHODS AND ANALYSIS: PITHIA is an open, multicentre, stepped-wedge cluster randomised study, involving all UK adult kidney transplant centres. At 4-monthly intervals, a group of 4-5 randomly selected clusters (transplant centres) will be given access to remote, urgent, digital histopathology (total intervention period, 24 months). The trial has two primary end points: it is powered for an 11% increase in the proportion of primary kidney offers from deceased donors aged over 60 years that are transplanted, and a 6 mL/min increase in the estimated glomerular filtration rate of recipients at 12 months post-transplant. This would equate to an additional 120 kidney transplants performed in the UK annually. Trial outcome data will be collected centrally via the UK Transplant Registry held by NHS Blood and Transplant (NHSBT) and will be analysed using mixed effects models allowing for clustering within centres and adjusting for secular trends. An accompanying economic evaluation will estimate the cost-effectiveness of the service to the National Health Service. ETHICS AND DISSEMINATION: The study has been given favourable ethical opinion by the Cambridge South Research Ethics Committee and is approved by the Health Research Authority. We will present our findings at key transplant meetings, publish results within 4 years of the trial commencing and support volunteers at renal patient groups to disseminate the trial outcome. TRIAL REGISTRATION NUMBER: ISRCTN11708741; Pre-results.

Use of Organs From Hepatitis C Virus-Positive Donors for Uninfected Recipients: A Potential Cost-Effective Approach to Save Lives?

BACKGROUND: Organs from hepatitis C virus (HCV) seropositive (HCVpos) individuals are seldom used for transplantation because of the risk of disease transmission. Because transmitted HCV is now amenable to effective treatment, we estimated the potential impact of using HCVpos deceased donor organs for transplantation. METHODS: The Potential Donor Audit of patients (<80 years) dying in UK critical care units and the UK Transplant Registry was searched to identify HCVpos potential and proceeding deceased donors. Donor organ quality was assessed using validated donor organ quality indices. Cost analysis was performed by comparing the cumulative cost of direct-acting antivirals with hemodialysis and renal transplantation. RESULTS: Between 2009 and 2016, 120 patients identified from the Potential Donor Audit were not considered as potential donors because of the presence of HCV. Between 2000 and 2015, 244 HCVpos potential deceased donors were identified from the UK Transplant Registry, and 76 (31%) proceeded to donation, resulting in 63 liver, 27 kidney, and 2 heart transplants. Recipient and graft survival was not adversely impacted by donor HCVpos status. Most (69%) offered organs were declined because of positive virology although their quality was similar to that of other transplanted organs. The additional costs of treating recipients exposed to HCV by receiving a HCVpos kidney was cost-neutral with dialysis 5 years from transplantation. CONCLUSIONS: HCVpos donors represent a potential source of organs for HCV seronegative recipients as many good quality HCVpos donor organs are not currently used for transplantation. This change in practice may increase access to transplantation without having an adverse effect on transplant outcome.

Novel endoscopic management of buried bumper syndrome in percutaneous endoscopic gastrostomy: The Olympus HookKnife.

Buried bumper syndrome (BBS) is an uncommon but serious complication of percutaneous endoscopic ga-strostomy. It involves the internal fixation device, or "bumper", migrating into the gastric wall and subsequent mucosal overgrowth. We described a case series of four patients with BBS treated with a novel endoscopic technique using a HookKnife between June 2016 and February 2017. The HookKnife is a rotating L-shaped cutting wire designed for hooking tissue and pulling it away from the gastric wall towards the lumen. The technique was successful in all four cases with no complications. Each patient was discharged on the day of treatment. The HookKnife is a manoeuvrable, safe and effective device for endoscopic removal of buried bumpers and could avoid surgery in a high risk group of patients. To our knowledge this technique has not been described previously. We suggest that this technique should be added to the treatment algorithms for managing BBS.

Deceased Organ Donors With a History of Increased Risk Behavior for the Transmission of Blood-Borne Viral Infection: The UK Experience.

BACKGROUND: Deceased organ donors are routinely screened for behaviors that increase the risk of transmissible blood-borne viral (BBV) infection, but the impact of this information on organ donation and transplant outcome is not well documented. Our aim was to establish the impact of such behavior on organ donation and utilization, as well transplant recipient outcomes. METHODS: We identified all UK deceased organ donors from 2003 to 2015 with a disclosed history of increased risk behavior (IRB) including intravenous drug use (IVDU), imprisonment and increased risk sexual behavior. RESULTS: Of 17 262 potential donors, 659 (3.8%) had IRB for BBV and 285 (1.7%) were seropositive for BBV, of whom half had a history of IRB (mostly IVDU [78.5%]). Of actual donors with IRB, 393 were seronegative for viral markers at time of donation. A history of recent IVDU was associated with fewer potential donors proceeding to become actual organ donors (64% vs 75%, P = 0.007). Donors with IRB provided 1091 organs for transplantation (624 kidneys and 467 other organs). Transplant outcome was similar in recipients of organs from donors with and without IRB. There were 3 cases of unexpected hepatitis C virus transmission, all from an active IVDU donor who was hepatitis C virus seronegative at time of donation, but was found to be viremic on retrospective testing. CONCLUSIONS: Donors with a history of IRB provide a valuable source of organs for transplantation with good transplant outcomes and there is scope for increasing the use of organs from such donors.

Transplantation of organs from deceased donors with meningitis and encephalitis: a UK registry analysis.

BACKGROUND: Deceased organ donors, where the cause of death is meningitis or encephalitis, are a potential concern because of the risks of transmission of a potentially fatal infection to recipients. METHODS: Using the UK Transplant Registry, a retrospective cohort analysis of deceased organ donors in the UK was undertaken to better understand the extent to which organs from deceased donors with meningitis and/or encephalitis (M/E) (of both known and unknown cause) have been used for transplantation, and to determine the associated recipient outcomes. RESULTS: Between 2003 and 2015, 258 deceased donors with M/E were identified and the causative agent was known in 188 (72.9%). These donors provided 899 solid organs for transplantation (455 kidneys and 444 other organs). The only recorded case of disease transmission was from a donor with encephalitis of unknown cause at time of transplantation who transmitted a fatal nematode infection to 2 kidney transplant recipients. A further 3 patients (2 liver and 1 heart recipient) died within 30 days of transplantation from a neurological cause (cerebrovascular accident) with no suggestion of disease transmission. Overall, patient and graft survival in recipients of organs from donors with M/E were similar to those for all other types of deceased organ donor. CONCLUSION: Donors dying with M/E represent a valuable source of organs for transplantation. The risk of disease transmission is low but, where the causative agent is unknown, caution is required.

Kidney donation after circulatory death (DCD): state of the art.

The use of kidneys from controlled donation after circulatory death (DCD) donors has the potential to markedly increase kidney transplants performed. However, this potential is not being realized because of concerns that DCD kidneys are inferior to those from donation after brain-death (DBD) donors. The United Kingdom has developed a large and successful controlled DCD kidney transplant program that has allowed for a substantial increase in kidney transplant numbers. Here we describe recent trends in DCD kidney donor activity in the United Kingdom, outline aspects of the donation process, and describe donor selection and allocation of DCD kidneys. Previous UK Transplant Registry analyses have shown that while DCD kidneys are more susceptible to cold ischemic injury and have a higher incidence of delayed graft function, short- and medium-term transplant outcomes are similar in recipients of kidneys from DCD and DBD donors. We present an updated, extended UK registry analysis showing that longer-term transplant outcomes in DCD donor kidneys are also similar to those for DBD donor kidneys, and that transplant outcomes for kidneys from expanded-criteria DCD donors are no less favorable than for expanded-criteria DBD donors. Accordingly, the selection criteria for use of kidneys from DCD donors should be the same as those used for DBD donors. The UK experience suggests that wider international development of DCD kidney transplantation programs will help address the global shortage of deceased donor kidneys for transplantation.

Defining delayed graft function after renal transplantation: simplest is best.

BACKGROUND: Delayed graft function (DGF) after renal transplantation can be diagnosed according to several different definitions, complicating comparison between studies that use DGF as an endpoint. This is a particular problem after transplantation with kidneys from donation after circulatory death (DCD) kidneys, because DGF is common, and its relationship to early graft failure may differ depending on the definition of DGF. METHODS: The presence of DGF in 213 donation after brain death (DBD) and 312 DCD kidney transplants from October 2005 to August 2011 was determined according to 10 different, but widely used, definitions (based on dialysis requirements, creatinine changes, or both). The relationship of DGF to graft function and graft survival was determined. RESULTS: The incidence of DGF varied widely depending on the definition used (DBD; 24%-70%: DCD; 41%-91%). For kidneys from DCD donors, development of DGF was only associated with poorer 1-year estimated glomerular filtration rate for 1 of 10 definitions of DGF, and no definition of DGF was associated with impaired graft survival. Conversely, for DBD kidneys, DGF, as defined in 9 of 10 different ways, was associated with poorer 1-year estimated glomerular filtration rate and inferior graft survival. Importantly, the predictive power for poorer transplant outcome was comparable for all definitions of DGF. CONCLUSION: No definition of DGF is superior. We suggest that the most widely used and most easily calculated definition--the use of dialysis in the first postoperative week--should be universally adopted as the definition of DGF clinically and as a study endpoint.

Effect of donor age and cold storage time on outcome in recipients of kidneys donated after circulatory death in the UK: a cohort study.

BACKGROUND: Use of kidneys donated after controlled circulatory death has increased the number of transplants undertaken in the UK but there remains reluctance to use kidneys from older circulatory-death donors and concern that kidneys from circulatory-death donors are particularly susceptible to cold ischaemic injury. We aimed to compare the effect of donor age and cold ischaemic time on transplant outcome in kidneys donated after circulatory death versus brain death. METHODS: We used the UK transplant registry to select a cohort of first-time recipients (aged ≥ 18 years) of deceased-donor kidneys for transplantations done between Jan 1, 2005, and Nov 1, 2010. We did univariate comparisons of transplants from brain-death donors versus circulatory-death donors with χ tests for categorical data and Wilcoxon tests for non-parametric continuous data. We used Kaplan-Meier curves to show graft survival. We used Cox proportional hazards regression to adjust for donor and recipient factors associated with graft-survival with tests for interaction effects to establish the relative effect of donor age and cold ischaemia on kidneys from circulatory-death and brain-death donors. FINDINGS: 6490 deceased-donor kidney transplants were done at 23 centres. 3 year graft survival showed no difference between circulatory-death (n=1768) and brain-death (n=4127) groups (HR 1·14, 95% CI 0·95-1·36, p=0·16). Donor age older than 60 years (compared with <40 years) was associated with an increased risk of graft loss for all deceased-donor kidneys (2·35, 1·85-3·00, p<0·0001) but there was no increased risk of graft loss for circulatory-death donors older than 60 years compared with brain-death donors in the same age group (p=0·30). Prolonged cold ischaemic time (>24 h vs <12 h) was not associated with decreased graft survival for all deceased-donor kidneys but was associated with poorer graft survival for kidneys from circulatory-death donors than for those from brain-death donors (2·36, 1·39-4·02, p for interaction=0·004). INTERPRETATION: Kidneys from older circulatory-death donors have equivalent graft survival to kidneys from brain-death donors in the same age group, and are acceptable for transplantation. However, circulatory-death donor kidneys tolerate cold storage less well than do brain-death donor kidneys and this finding should be considered when developing organ allocation policy. FUNDING: UK National Health Service Blood and Transplant; Cambridge National Institute for Health Research Biomedical Research Centre.