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Ex vivo normothermic perfusion (EVNP) is increasingly recognised as a viability tool to increase organ utilisation in deceased donor transplantation. We report the use of EVNP to assess graft perfusion quality following indication nephrectomy and back-bench arterial reconstruction in a case of renal artery stenosis, unamenable to endovascular treatment. Once explanted, it was not possible to effectively cold perfuse the graft through the main renal artery or collaterals. An arterial reconstruction was performed with patch angioplasty using the largest collateral creating a single common stem. EVNP was used to assess organ perfusion and, therefore, viability. Excellent global perfusion was evident alongside urine production, demonstrating that the arterial reconstruction was satisfactory. A patient with end-stage renal disease was consented with particular attention to the uncertainty of the underlying donor disease process and long-term outcome of the reconstruction. Primary function was achieved and recipient estimated glomerular filtration rate (eGFR) remains stable at 58 mL/min/1.73 m² at 6 months.

A key limitation in assessing the therapeutic impact of non-pharmacological approaches to treating hypertension is the method of reporting outcomes. Reducing the medications required to achieve the same blood pressure may be reported separately to a reduction in the blood pressure without change in medication, and thus lessen the reported beneficial impact of treatment. This study aims to derive a novel scoring system to gauge the therapeutic impact of non-drug treatment of hypertension by utilising a combination of excessive blood pressure and the number of anti-hypertensives into a combined score - the hypertensive index (HTi). The hypertensive index was empirically derived based on the systolic blood pressure and number of antihypertensive drugs, and applied retrospectively to a cohort undergoing intervention for renovascular hypertension. Subgroup and receiver operating characteristic analyses were used to compare the HTi to traditional methods of reporting outcomes. 99 patients were included. Following intervention, 46% had improvement in both medication load and blood pressure, 29% had benefit in blood pressure without reduction in medication load, 15% had reduction in medication load without significant change in blood pressure and 9% showed no benefit in either parameter. The HTi was superior in detecting benefit from intervention compared with measuring blood pressure or medication load alone (AUC 0.94 vs 0.85;0.84). The hypertensive index may be a more sensitive marker of treatment effect than assessing blood pressure measurements alone. The use of such scoring systems in future trial design may allow more accurate reporting of the effects of interventions for hypertension.

Purpose This prospective, observational first in human study evaluated the safety and effectiveness of WRAPSODYTM Cell-impermeable Endoprosthesis (Merit Medical Systems, Inc.) in the treatment of arteriovenous fistula and arteriovenous graft access circuit stenosis. Materials and Methods Investigators conducted a prospective analysis of 46 patients with access circuit stenosis from three centres. Treatment sites included the peripheral outflow veins (e.g. cephalic arch, basilic vein swing point; 16 fistula and 10 graft patients); the graft-vein anastomosis (9 patients); and the central veins (up to, but not including the SVC; 11 patients). Primary outcome measures included 30-day freedom from access circuit-related safety events and 30-day target lesion primary patency. Secondary outcome measures included procedural success; device- and procedure-related adverse events; target lesion primary patency; access circuit primary patency; and secondary patency. In-person follow-up was scheduled at 1, 3, 6, and 12 months. An independent data monitoring/clinical event committee adjudicated all reinterventions and device/procedure-relatedness for adverse events. Results All initial procedures were successful. All but one patient was free from safety events through the first 30 days (97.8% (45/46)). This event was not device-related. Over the remainder of the study, one adverse event was adjudicated as possibly device-related. Six- and 12-month target lesion primary patency rates were 97.7% (42/43) and 84.6.% (33/39), respectively. Six- and 12-month access circuit primary patency rates were 84.4% (38/45) and 65.9% (29/44), respectively. Conclusion Results suggest that the study device is safe and effective for treatment of stenoses in the peripheral and central veins of arteriovenous access circuits. Level of Evidence Level 2b, cohort study.

Background Pseudoaneurysm formation is common in standard thin-walled polytetrafluoroethylene (sPTFE) grafts, occurring in up to 10% of grafts, and is reported as the most common cause of graft loss for grafts more than 2 years old. The Gore® Acuseal™ graft is an early cannulation graft, needled before incorporation, and thus may be especially prone to pseudoaneurysm formation. In addition, as this is a relatively new product, there are limited data on long-term outcomes such as pseudoaneurysm. We report one center's experience of the incidence and etiological factors associated with pseudoaneurysm formation over 5 years and 265 grafts. Methods A total of 265 Acuseal grafts were placed in the last 5 years. All patients had prospective data entered into an electronic searchable patient record. Surveillance was performed with 3 monthly imaging (digital subtraction angiography or ultrasound), clinical examination, and hemodynamic performance. Data examined included the incidence, causative factors, and outcomes of pseudoaneurysm. Results Eleven grafts (4.15%) developed a pseudoaneurysm, with 2 patients developing significant hemorrhage. The median time to development of a pseudoaneurysm was 25 months interquartile range (IQR, 20-28 months). Several common etiological factors were identified. All but one patient had overuse of needling sites (n = 10; 90.9%). Other factors associated with pseudoaneurysm formation were inadequate surveillance (n = 9; 81.8%), venous outflow stenosis (n = 9; 81.8%), and anticoagulation/dual antiplatelet therapy (n = 7; 63.6%). Management included observation and needle rotation (n = 5; 45.5%), stent grafting (n = 3; 27.3%), or excision (n = 1; 9.1%) of the pseudoaneurysm. Surgical or endovascular augmentation of the venous outflow was required in 9 patients (81.8%). Graft ligation and explantation were required in 5 patients (45.5%) with graft preservation achieved in 6/11 patients (54.5%). Conclusions Pseudoaneurysm formation occurs less frequently in Acuseal grafts compared with historical data for standard PTFE grafts. Pseudoaneurysm formation did not occur in any graft within the first 13 months after implantation, suggesting early cannulation before incorporation is not by itself a risk factor for pseudoaneurysm development. Poor needling, venous stenosis, inadequate surveillance, and anticoagulation/dual antiplatelet therapy are remediable factors, and graft preservation is possible. Acuseal is a robust graft with lower rates of pseudoaneurysm formation on long-term follow-up than standard PTFE grafts.

There is presently a lack of organization and standardized reporting schema for arteriovenous graft (AVG) infections. The purpose of this article is to evaluate the various types of treatment modalities for access site infections through an analysis of current publications on AVG. Key proposals are made to support standardization in a data-driven manner to make infection reporting more uniform and thereby facilitate more meaningful comparisons between various dialysis modalities and AVG technologies.

It is inevitable that complications arising from surgical procedures are ascribed to surgical technique, and this applies to venous stenosis (VS) in arteriovenous grafts. However, despite a wide range of cellular studies, computer modelling, observational series and clinical trials, there remains uncertainty on whether surgical technique contributes to VS. This article reviews evidence from basic science, fluid dynamics and clinical data to try and rationalise the main surgical options to modify the occurrence of venous stenosis. There is sufficient data from diverse sources to make recommendations on clinical practice (size of target vein, shape of anastomosis, angle of approach, distance from venous needling, trauma to the target vein) whilst at the same time this emphasises the need to carefully report the practical aspects of surgical technique in future clinical trials.

Guidelines make no firm recommendations about surveillance of arteriovenous grafts as several randomised trials (RCT) have not shown a clear benefit in patency. However a more thorough review of these RCT based on epidemiological principles reveals significant limitations. In particular a key weakness of these older studies is the interventions performed for venous stenosis detected that was largely angioplasty. However, the observational data of modern stent-grafts shows a clear benefit over angioplasty, and thus seems to suggest that a modern well considered RCT is now mandated.

Background: Early cannulation arteriovenous grafts (ecAVG) for dialysis access are limited by reintervention for venous stenosis (VS) despite their good initial patency. Whilst stent-grafts (SG) have shown promise, the optimal sizing is unclear. Therefore, this study aims to determine if outflow vein diameter, SG diameter or these relative to each other (V:Sr) alters outcomes, and if so, which is more important. Methods: Retrospective analysis was performed of Gore® Acuseal® ecAVGs with VS treated with Gore® Viabahn® SG over a 7-year period. Primary patency (PP), time to thrombosis and functional patency were analysed by SG length/diameter, vein diameter and V:Sr. Results: We identified 114 ecAVGs with median follow-up 492 days (IQR 189–770). SG length and diameter did not correlate with PP, however, there was a significant relationship between vein diameter and PP (RR = 0.901 (0.832–0.975), p = 0.01) and between V:Sr and PP (RR = 0.462 (0.255–0.838), x2 = 5.866, p = 0.0015). The optimal V:Sr was ⩾1.4 (i.e. vein diameter at least 40% greater than the stent-graft; or ‘free-floating’ stent outflow) (RR = 2.759 (1.670–4.558), p Conclusions: Placement of the SG outflow into a relatively larger segment of vein was associated with a significant increase in PP independent of the absolute vein diameter. This suggests that larger calibre SG which are apposed to the vein wall are not required for optimal primary patency, and indeed should be actively avoided. Instead, a ‘free-floating’ stent outflow which is undersized relative to the recipient vein (whilst maintaining a minimum anchoring calibre) is recommended where possible. This should be considered during intervention and may require selection of longer devices, where practical, to bring the stent outflow into a larger vein segment. Level of Evidence: Level 3a, Non-randomised controlled cohort/follow-up study

Arteriovenous fistula (AVF) is the preferred type of vascular access for maintenance haemodialysis but it may contribute to maladaptive cardiovascular remodelling. We studied the effect of AVF creation on cardiac structure and function in patients with chronic kidney disease (CKD). In this prospective cohort study patients with CKD listed for first AVF creation underwent cardiac magnetic resonance (CMR) imaging at baseline and at 6 weeks. All participants had ultrasound measurements of fistula blood flow at 6 weeks. The primary outcome was the change in left ventricular (LV) mass. Secondary outcomes included changes in LV volumes, LV ejection fraction, cardiac output, LV global longitudinal strain and N-terminal-pro B-type natriuretic peptide (NT-proBNP). A total of 55 participants were enrolled, of whom 40 (mean age 59 years) had AVF creation and completed both scans. On the second CMR scan, a mean increase of 7.4 g (95% CI 1.1–13.7, p = 0.02) was observed in LV mass. Significant increases in LV end-diastolic volumes (p = 0.04) and cardiac output (p = 0.02) were also seen after AVF creation. No significant changes were observed in LV end-systolic volumes, LV ejection fraction, NT-proBNP and LV global longitudinal strain. In participants with fistula blood flows ≥ 600 mL/min (n = 22) the mean increase in LV mass was 15.5 g (95% CI 7.3–23.8) compared with a small decrease of 2.5 g (95% CI − 10.6 to 5.6) in participants with blood flows

Background: Early-cannulation arteriovenous grafts (ecAVG) have good initial patency, but frequent episodes of reintervention for venous stenosis (VS) and thrombosis limit their use. Stent grafts (SG) have shown promise in reducing re-interventions and improving functional patency for dysfunctional ecAVG and recurrent VS. There is little data on the impact of stent grafts as the first elective procedure for VS. The aim of this study was to determine firstly, if treating VS whilst asymptomatic has a better outcome than treating after presentation with thrombosis; and secondly, to determine the best initial treatment for asymptomatic VS: SG or angioplasty. Methods: A retrospective study was performed of 259 ecAVG with a sutured anastomosis. The case-mix and outcomes of 153 who presented with VS was analysed by presentation (elective at surveillance or emergency following thrombosis), and then for only elective patients, by treatment (SG vs angioplasty). Results: There was no significant difference in case-mix and time to presentation by mode of presentation (100 elective and 53 with thrombosis) other than a higher rate of pro-thrombotic disorders in thrombosed ecAVG. Thrombosed ecAVG had poorer outcomes with increased re-intervention rates and thrombosis in the following year, and reduced long-term functional patency. In patients presenting electively, primary SG rather than angioplasty led to significantly reduced thrombosis rates, a longer time to re-intervention in the following year, and superior long-term functional patency. The use of SG was the same in both groups. Both the mode of presentation and the type of intervention performed were independently predictive of a poorer subsequent functional patency. Conclusions: Primary elective stent-grafting may be the optimal strategy to reducing maintenance costs with ecAVG.

Objective: \ud The predicted outcomes of autogenous arteriovenous (AV) hemodialysis access creation are predominantly based on historical data; however, both the hemodialysis population and clinical practices have changed significantly during the last decade. This study examined contemporary AV access clinical use and patencies.\ud \ud Methods: \ud A multicenter observational cohort study was performed of all new AV accesses created in Scotland in 2015. The primary end point was efficacy assessed by successful AV access use for a minimum of 30 days and primary, primary assisted, and secondary patency at 1 year. Data obtained included all interventions to maintain or to restore patency. Predictors of patency loss including demographics, comorbid conditions, dialysis status, AV access location, duplex ultrasound surveillance, procedures, prior access, and antiplatelets were assessed. Kaplan-Meier and competing risks analyses were performed to estimate the probability of AV access failure. All patients were followed up for at least 1 year or had a censoring event.\ud \ud Results: \ud A total of 582 AV accesses were created in 537 patients (mean age, 60 [standard deviation, 14] years; 60% men; 42% with diabetes) in nine adult renal centers. Mean follow-up was 11.8 (standard deviation, 7.6) months. By the end of the follow-up, 322 (55.3%) AV accesses were successfully used for dialysis. At 1 year, 48% (95% confidence interval [CI], 44-52) of AV accesses had primary patency, (95% CI, 63-71) had primary assisted patency, and 69% (95% CI, 65-73) had secondary patency. The leading cause of primary patency loss was primary failure (30%). An average of 0.48 intervention per patient-year was required to maintain patency. On multivariable analysis, patency was better for an upper arm than for a forearm AV access (1-year secondary patency of upper arm vs forearm AV accesses, 74% vs 58%). The cumulative hazard and incident functions for AV access failure were 31% (95% CI, 27-35) and 23% (95% CI, 20-27) at 1 year, respectively.\ud \ud Conclusions: \ud Despite advances in recent years with preoperative vessel assessment and surveillance, patency rates have not improved, with primary failure remaining the major obstacle. Competing events should be taken into consideration; otherwise, biases may occur with overestimation of the probability of AV access failure.

Objectives Ferumoxytol is an alternative to gadolinium-based compounds as a vascular contrast agent for magnetic resonance angiography (MRA), particularly for patients with chronic kidney disease (CKD). However, dose-related efficacy data are lacking. We aimed to determine the optimal (minimum effective) dose of ferumoxytol for MRA in patients with CKD. Methods Ferumoxytol-enhanced MRA (FeMRA) was performed at 3.0 T in patients with CKD after dose increments up to a total of 4 mg/kg. Image quality was assessed by contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) in the abdominal aorta and inferior vena cava. Quadratic regression analyses were performed to estimate the effects of dose increments on CNR and SNR. Results Twenty-three patients underwent FeMRA (mean age 60 [SD 13] years, 87% men, 48% had diabetic nephropathy) with cumulative doses of 0, 1, 2, 3 and 4 mg/kg of ferumoxytol. On regression analyses, a parabolic relationship was observed between ferumoxytol dose and signal with progressive signal loss using doses exceeding 4 mg/kg. A dose of 3 mg/kg achieved ≥ 75% of predicted peak CNR and SNR and images were deemed of excellent diagnostic quality. Conclusions In patients with CKD undergoing FeMRA, a dose of 3 mg/kg provides excellent arterial and venous enhancement. The benefits of increasing the dose to a theoretically optimal value of 4 mg/kg appear to be negligible and likely of minimal, if any, diagnostic value. Key Points • Ferumoxytol is used off-label as an MRI contrast agent but dose-related data are lacking. • In patients with CKD requiring MR angiography, a dose of 3 mg/kg provides excellent vascular enhancement. Electronic supplementary material The online version of this article (10.1007/s00330-019-06137-4) contains supplementary material, which is available to authorized users.

Funder: GlaxoSmithKline; funder-id: http://dx.doi.org/10.13039/100004330, Introduction: Delayed graft function (DGF) following renal transplantation is a manifestation of acute kidney injury (AKI) leading to poor long-term outcome. Current treatments have limited effectiveness in preventing DGF. Interleukin-18 (IL18), a biomarker of AKI, induces interferon-γ expression and immune activation. GSK1070806, an anti-IL18 monoclonal antibody, neutralizes activated (mature) IL18 released from damaged cells following inflammasome activation. This phase IIa, single-arm trial assessed the effect of a single dose of GSK1070806 on DGF occurrence post donation after circulatory death (DCD) kidney transplantation. Methods: The 3 mg/kg intravenous dose was selected based on prior studies and physiologically based pharmacokinetic (PBPK) modeling, indicating the high likelihood of a rapid and high level of IL18 target engagement when administered prior to kidney allograft reperfusion. Utilization of a Bayesian sequential design with a background standard-of-care DGF rate of 50% based on literature, and confirmed via extensive registry data analyses, enabled a statistical efficacy assessment with a minimal sample size. The primary endpoint was DGF frequency, defined as dialysis requirement ≤7 days post transplantation (except for hyperkalemia). Secondary endpoints included safety, pharmacokinetics and pharmacodynamic biomarkers. Results: GSK1070806 administration was associated with IL18-GSK1070806 complex detection and increased total serum IL18 levels due to IL18 half-life prolongation induced by GSK1070806 binding. Interferon-γ−induced chemokine levels declined or remained unchanged in most patients. Although the study was concluded prior to the Bayesian-defined stopping point, 4/7 enrolled patients (57%) had DGF, exceeding the 50% standard-of-care rate, and an additional two patients, although not reaching the protocol-defined DGF definition, demonstrated poor graft function. Six of seven patients experienced serious adverse events (SAEs), including two treatment-related SAEs. Conclusion: Overall, using a Bayesian design and extensive PBPK dose modeling with only a small sample size, it was deemed unlikely that GSK1070806 would be efficacious in preventing DGF in the enrolled DCD transplant population. Trial registration: NCT02723786.

There is a new emphasis on tailoring appropriate vascular access for hemodialysis to patients and their life-plans, but there is little known about the optimal use of newer devices such as early-cannulation arteriovenous grafts (ecAVG), with studies utilising them in a wide variety of situations. The aim of this study was to determine if the outcome of ecAVG can be predicted by patient characteristics known pre-operatively. This retrospective analysis of 278 consecutive ecAVG with minimum one-year follow-up correlated functional patency with demographic data, renal history, renal replacement and vascular access history. On univariate analysis, aetiology of renal disease, indication for an ecAVG, the number of previous tunnelled central venous catheters (TCVC) prior to insertion of an ecAVG, peripheral vascular disease, and BMI were significant associates with functional patency. On multivariate analysis the number of previous TCVC, the presence of peripheral vascular disease and indication were independently associated with outcome after allowing for age, sex and BMI. When selecting for vascular access, understanding the clinical circumstances such as indication and previous vascular access can identify patients with differing outcomes. Importantly strategies that result in TCVC exposure have an independent and cumulative association with decreasing long-term patency for subsequent ecAVG. As such, TCVC exposure is best avoided or minimised particularly when ecAVG can be considered.

Objective Tunneled central venous catheter infection (TCVCi) is a common complication that often necessitates removal of the TCVC and a further TCVC. Theoeretically, insertion of an early-cannualtion graft (ecAVG) early after TCVC infection is possible but not widely practiced with concerns over safety and infection in the ecAVG. With 8 years of ecAVG experience, the aim of this study was to compare the outcomes following TCVC infection, comparing replacement with TCVC (TCVCr) versus immediate ecAVG (ecAVGr). Methods Retrospective comparison of two cohorts, who underwent replacement of an infected TCVC either by an early cannulation graft (n = 18) or by a further central catheter (n = 39). Data were abstracted from a prospectively completed electronic patient record and collected on patient demographics, TCVC insertion, duration and infection, including culture proven bacteriaemia and subsequent access interventions. Results 18/299 patients identified from 2012-2020 had an ecAVG implanted as treatment for a TCVCi. In a one-year time-period (1/1/2015 -31/12/2015) out of 222 TCVC inserted, 39 were as a replacement following a TCVCi. No patient with an ecAVGr developed an immediate infection, nor complication from the procedure. The rate of subsequent vascular access infection was significantly more frequent for those with TCVCr than with an ecAVGr (0.6 vs. 0.1/patient/ 1000 HD days, p Conclusion An ecAVG early following a TCVC infection is safe, reduces the incidence of subsequent infectious complications and reduces the number of TCVC required, with a better functional patency.

Background Duplex US is performed routinely for vascular mapping prior to arteriovenous fistula (AVF) creation for hemodialysis but cannot demonstrate the central vasculature. Ferumoxytol, an iron oxide nanoparticle, provides an alternative to gadolinium contrast material for MR angiography for safe use in chronic kidney disease (CKD). Purpose To assess the clinical utility of ferumoxytol-enhanced MR angiography compared with duplex US for vascular mapping before upper limb AVF creation in participants with CKD. Materials and Methods In a prospective comparative study (ClinicalTrials.gov: NCT02997046) from December 2016 to August 2018, participants with CKD underwent ferumoxytol-enhanced MR angiography and duplex US. Two independent readers evaluated vessels for diameter, stenosis or occlusion, arterial disease, and central stenosis. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to assess intra- and interreader variability. On the basis of accepted standards for AVF creation, an algorithm was developed to predict AVF outcome based on imaging findings. Multivariable regression models used AVF success as the dependent variable and age, sex, and duplex US or ferumoxytol-enhanced MR angiography findings as independent variables. Results Fifty-nine participants with CKD (mean age, 59 years ± 13 [standard deviation]; 30 women) were evaluated. A total of 51 fistulas were created, of which 24 (47%) were successful. Ferumoxytol-enhanced MR angiography showed excellent inter- and intrareader repeatability (ICC, 0.84-0.99) for all variables assessed. In addition to revealing 15 central vasculature stenoses, ferumoxytol-enhanced MR angiography resulted in characterization of 88 of 236 (37%) of the arterial sections examined as unsuitable for AVF creation compared with 61 of 236 (26%) sections with duplex US (

Background and Aims Arteriovenous fistula (AVF) is considered the preferred type of access for maintenance haemodialysis. The creation of an AVF may contribute to maladaptive cardiovascular remodelling. We conducted a study to evaluate the effect of AVF creation on cardiac structure and function in patients with end-stage renal disease (ESRD). Method In this prospective cohort study, patients with ESRD listed for AVF creation underwent cardiac magnetic resonance imaging at baseline and at 6 weeks. All participants had ultrasound measurements of AVF blood flow at 6 weeks. The primary outcome was the change in left ventricular (LV) mass. Secondary outcomes included changes in LV volumes, left atrial volume, LV ejection fraction, LV global longitudinal strain, cardiac output/index, and septal thickness. Results A total of 65 patients were enrolled, of whom 40 had an AVF creation and completed both scans. Patients were divided into 2 groups based on AVF blood flows: 22 in the high flow group (≥ 600mL/min) and 18 in the low flow group (< 600mL/min). On the second cardiac magnetic resonance scan, a mean increase of 7.4 g (95% CI, 1.1–13.7, P=0.02) was observed in LV mass; in the high flow group the mean increase was 15.5 g (95% CI, 7.3–23.8) compared with a small decrease of 2.5 g (95% CI, −10.6 to 5.6) in the low flow group (P=0.003). Significant increases in LV end-diastolic volumes, cardiac output, and cardiac index were also seen after AVF creation (P Conclusion Creation of AVF in adults with ESRD resulted in significant increase of LV myocardial mass early after surgery.

BACKGROUND The presence of a lower limb arteriovenous graft (LL-AVG) is indicative of a group of complex hemodialysis patients who have precarious long-term vascular access. The aim of this study is to describe our experience of the clinical decisions and interactions between LL-AVG and renal transplantation. METHODS The records of 23 patients who received a transplant in the presence of a LL-AVG between 2010 and 2018 were analyzed: firstly, to determine whether patients with a LL-AVG received extended criteria transplants, the implantation procedure, and the management of the LL-AVG in the post-operative period. RESULTS Seventeen patients (74%) had "end-stage access" and were thus considered for all offer stratified by the kidney donor profile index (KDPI) and donor type (DBD or DCD). In eleven patients (48%), a kidney with a high risk of delayed graft function was transplanted. Same-sided renal transplantation occurred in only 35% of cases, and of these, only one LL-AVG was ligated immediately to improve transplant perfusion. CONCLUSION A patient-based approach applied in decision-making on management of the LL-AVG post-transplantation should include (a) the likelihood of delayed graft function, (b) the need for post-operative hemodialysis, (c) the side of proposed transplant compared to the LL-AVG, and (d) local complications.

To describe a novel endovascular technique for intracaval cement retrieval after spinal surgery. We produced a replica of the intracaval cement fragment and a 3D print to plan the endovascular procedure. A woven caval filter was modified with two drawstring sutures to be used as fishing net. We used a 10F sheath in the right internal jugular vein to place the caval filter proximal to the floating fragment, and a 24F sheath in the right femoral vein was the working access. After the deployment of the caval filter, the following steps were performed through the 24F sheath: (A) The drawstring sutures were snared and retrieved to the skin surface in the groin; (B) the fragment was secured with two snare catheters from the femoral access and one through the lumen of the caval filter; (C) the fragment was broken off with a snared guide wire at the base; (D) the smallest fragment was removed directly with the snare; (E) the larger dislodged fragment was controlled within the periprocedural caval filter by tightening the drawstring and removed through the 24F sheath. Cement fragments located in the inferior vena cava after cement-augmented spinal surgery procedures can be safely removed by the described fishing net technique.

Objective: To explore putative different impacts of delayed graft function(DGF) on long-term graft survival in kidneys donated after brain death (DBD)and circulatory death (DCD).Background: Despite a 3-fold higher incidence of DGF in DCD grafts, largestudies show equivalent long-term graft survival for DBD and DCD grafts.This observation implies a differential impact of DGF on DBD and DCD graftsurvival. The contrasting impact is remarkable and yet unexplained.Methods: The impact of DGF on DBD and DCD graft survival was evaluatedin 6635 kidney transplants performed in The Netherlands. DGF severity andfunctional recovery dynamics were assessed for 599 kidney transplantsperformed at the Leiden Transplant Center. Immunohistochemical staining,gene expression profiling, and Ingenuity Pathway Analysis were used toidentify differentially activated pathways in DBD and DCD grafts.Results: While DGF severely impacted 10-year graft survival in DBD grafts(HR 1.67; P < 0.001), DGF did not impact graft survival in DCD grafts (HR1.08; P ¼ 0.63). Shorter dialysis periods and superior posttransplant eGFRs inDBD grafts show that the differential impact was not caused by a more severeDGF phenotype in DBD grafts. Immunohistochemical evaluation indicatesthat pathways associated with tissue resilience are present in kidney grafts.Molecular evaluation showed selective activation of resilience-associatedpathways in DCD grafts.Conclusions: This study shows an absent impact of DGF on long-term graftsurvival in DCD kidneys. Molecular evaluation suggests that the differentialimpact of DGF between DBD and DCD grafts relates to donor-type specificactivation of resilience pathways in DCD grafts.

Background: A self-administered 11 item vascular access specific quality of life measure (VASQoL) was previously derived from detailed qualitative interviews with adult patients with kidney failure who have experienced vascular access using the Capabilities Approach as a theoretical base. This study reports the psychometric validation of the VASQoL measure including its reliability, content validity and responsiveness to change. Methods: Cognitive interviews were conducted with 23 adult patients with kidney failure after completion of the VASQoL measure. Focus group discussion with a vascular access professional multidisciplinary team was undertaken ( n = 8) and subsequently a further 101 adult kidney failure patients with vascular access (TCVC, AVF or AVG) completed the digital VASQoL measure, EQ-5D and SF-36 questionnaires in a longitudinal study with prospectively recorded vascular access events. Results: Transcript analysis of cognitive interviews after VASQoL completion indicated that the content was comprehensive and well understood by participants. Assessment of Internal reliability for the VASQoL measure was high (Cronbach’s alpha 0.858). Test-retest reliability of the overall VASQoL measure was high (intra class correlation coefficient 0.916). In those patients who experienced a vascular access event, significant differences were observed in paired analysis of the VASQoL physical domain questions and vascular access function domain questions and in the EQ-5D usual activities, pain and anxiety domains. In those with no vascular access event, variation was observed in longitudinal analysis in VASQoL questions relating to worry about VA function and capability domains, whilst no variation was observed in the EQ5D measure. Conclusion: The VASQoL measure has good internal consistency, test-retest reliability, convergent validity and responsiveness to change for clinically relevant vascular access outcomes. This provides a validated, vascular access specific quality of life measure that can be used in future trials of vascular access, evaluation of new technologies and routine use as a patient reported outcome measure (PROM).

Early cannulation arteriovenous grafts (ecAVGs) are proposed as an alternative to tunneled central venous catheters (TCVCs) in patients requiring immediate vascular access for hemodialysis (HD). We compared bacteremia rates in patients treated with ecAVG and TCVC.The study randomized 121 adult patients requiring urgent vascular access for HD in a 1:1 fashion to receive an ecAVG with or without (+/-) an arteriovenous fistula (AVF; n = 60) or TCVC+/-AVF (n = 61). Patients were excluded if they had active systemic sepsis, no anatomically suitable vessels, or an anticipated life expectancy 3 months. The primary end point was the culture-proven bacteremia rate at 6 months, with the trial powered to detect a reduction in bacteremia from 24% to 5% (α = .05, β = .8). Secondary end points included thrombosis, reintervention, and mortality. A cost-effectiveness analysis was also performed.Culture-proven bacteremia developed in 10 patients (16.4%) in the TCVC arm ≤6 months compared with two (3.3%) in the ecAVG+/-AVF arm (risk ratio, 0.2; 95% confidence interval, 0.12-0.56; P = .02). Mortality was also higher in the TCVC+/-AVF cohort (16% [n = 10] vs 5% [n = 3]; risk ratio, 0.3; 95% CI, 0.08-0.45; P = .04). The difference in treatment cost between the two arms was not significant (£11,393 vs £9692; P = .24).Compared with TCVC+/-AVF, a strategy of ecAVG+/-AVF reduced the rate of culture-proven bacteremia and mortality in patients requiring urgent vascular access for HD. The strategy also proved to be cost-neutral.

Purpose Published registry data demonstrate longstanding variation in the utilisation of different vascular access (VA) modalities between Scottish renal units; this may reflect different clinical processes between centres. A comprehensive appraisal was undertaken to understand the processes underpinning VA creation and maintenance across Scotland. Methods A mixed methods approach was utilised. Fifty-two semi-structured interviews were conducted with patients and clinicians in all ten, adult and paediatric, Scottish renal units. Interview transcripts were subjected to thematic analysis. Clinical activity data were prospectively collected for six weeks, and correlated with registry data. Results VA accounts for a large clinical workload. There was significant inter-centre variation in the utilisation of different VA modalities, and patients described frustrating, dissatisfying experiences. VA creation and maintenance pathways functioned best when nephrologists, surgeons and radiologists were co-located on the same campus with close multi-disciplinary working, protected clinical time, and proactive VA maintenance. No unit routinely measured or discussed procedure outcomes or strategic aspects of their service. Conclusions Varied clinical outcomes reflected varied clinical processes. Optimised clinical pathways, staff education and measurement of clinical outcomes may improve VA service quality and facilitate safer, more effective, patient-centred care.

Although kidney transplantation is the treatment of choice for suitable patients with end-stage kidney disease, approximately 25% of chronic kidney disease (CKD) patients have peripheral arterial disease (PAD) ([1][1]). Computed tomography angiography (CTA) can identify patients requiring

In 2013, the UK national renal registry established 57,000 adults in the UK were treated for advanced kidney failure, 23,683 (42%) receiving haemodialysis. Haemodialysis patients face some of the highest treatment burden in the National Health Service (NHS) and are among the most 'expensive' to treat. In addition, patients endure complex treatment trajectories. In this study, we have sought to gather and synthesise the opinion of clinical and Human Computer Interaction (HCI) domain experts (n=9) to establish a set of initial design requirements in order to test the feasibility of developing a digital aid (i.e. electronic haemodialysis patient portal) to support patients in the course of their treatment. Expert feedback was gathered by means of interviews and focus groups in order to instruct design requirements for a haemodialysis patient portal.

Introduction: Kidney transplantation offers superior quality of life and survival compared to dialysis although involves invasive procedures, hospitalisation, clinic attendances, and risk of intercurrent illness. In this study we demonstrate visually and numerically the breadth and depth of activity incurred by transplantation when considering the patient journey. Methods: Consecutive patients in the Glasgow Renal and Transplant Unit (UK) in receipt of a kidney transplant during 2015 were studied. Demographics and events of interest were collated from electronic patient records for 2 years following transplantation. Results: 132 patients were transplanted. The median number of clinical contact days over 2 years was 47; 12 in-patient days, 3 day ward attendances, and 28 out-patient appointments. 46% of clinical contact days occurred in the first 90 days. In-patient days, were higher in both BMI >30kg/m2 and in extended criteria donor subgroups. 64/132 (48.5%) experienced at least one clinically significant infection requiring antibiotics, antivirals, and/or a reduction in immune-suppression; 9/132 (6.8%) experienced 10 or more infections. An average of 8.2 imaging studies were undertaken per patient; half of these within the first 90 days (540/1090, 49.5%). Transplant biopsy was performed on 86 occasions in 50/132 (37.9%); 45/86 biopsies (52.3%) occurred in the first 90 days. 16/132 (12.1%) experienced an episode of biopsy-proven acute rejection. Over 2 years, 11/132 lost graft function (8.3%), and 8/132 recipients died (6.1%). Discussion: The effect of aggregating these data is to provide a granular map of the post-transplant period. This offers greater insights into what patients may expect following receipt of their kidney transplant, the resources required to support care longitudinally, and seeks to assist in the evolution of care models and definitions of quality.

Peripheral vascular disease is common with varying degrees of severity. It is a marker of systemic vascular disease and is associated with increased cardiovascular and overall mortality. There are numerous modifiable and non-modifiable risk factors associated with peripheral vascular disease. In this chapter we discuss the aetiology, investigation and treatment of peripheral vascular disease using an evidence-based approach.

Objectives:\ud \ud There has been considerable change in the practice of deceased kidney transplantation in the past 15 years, with more extreme phenotypes implanted. The aim of this study was to determine whether increased use of expanded criteria donors (extended criteria donors and donors after circulatory death) affected clinical outcomes, including the incidence and pattern of delayed graft function.\ud Methods and materials:\ud \ud A retrospective analysis of 1359 renal transplants was performed over 15 years. The first 10 years of data (group 1) were compared with the subsequent 5 years (group 2). Outcomes were analyzed at 6 months and 12 months in addition to serum creatinine and patterns of delayed graft function (posttransplant times: on hemodialysis, to peak creatinine, for creatinine to half, and for creatinine to fall within 10% of baseline).\ud Results:\ud \ud There was a significant increase in the percentage of expanded criteria donor allografts used in group 2 with a significant increase in the incidence of delayed graft function. Despite this, serum creatinine and the incidence of biopsy-proven acute rejection had both improved in group 2. Group 2 expanded criteria donor kidneys had a significantly lower incidence of type 1 delayed graft function and a significantly higher incidence of types 3 and 4 delayed graft function. Time for creatinine to half in both groups was the best predictor of a serum creatinine

Continuous suturing techniques have conventionally been used for the end-to-side anastomoses of radiocephalic fistulas (RCFs); however, primary patency rates are poor. Only 50% to 60% of RCFs ever achieve functional patency. We hypothesized that a hybrid interrupted-continuous suturing technique (as used in many microsurgical procedures) may improve outcomes in fistulas constructed from small vessels.A randomized controlled trial comparing hybrid interrupted-continuous (n = 42) with continuous (n = 36) suturing techniques for RCF was undertaken. Patients were excluded if vessels were1.8 mm in diameter or if previous ipsilateral fistula had been attempted. A priori power calculation indicated that a sample size of 78 patients was required to detect an improvement in patency from 50% to 80% (α = .05, β = .8). The primary end point was primary patency at 6 weeks (assessed by a blinded observer for the presence of thrill and bruit). Secondary end points were immediate patency, functional patency (assessed clinically and by ultrasound) at 6 weeks, and presence of anastomotic stenosis.Groups were comparable for basic patient demographics, operating surgeon, and vessel diameter as measured on preoperative ultrasound (mean age, 58.9 ± 13 years; 68% male). Primary patency at 6 weeks was higher in the hybrid interrupted-continuous suturing technique group (71% vs 47%; P = .01). Immediate patency was also higher in the hybrid interrupted-continuous suturing technique group (93% vs 67%; P.001). There was no significant difference in functional patency at 6 weeks (52% vs 36%; P = .18). Three patients developed an anastomotic stenosis. All were in the hybrid interrupted-continuous suturing technique group. One patient from the interrupted suturing technique cohort required re-exploration for bleeding.A hybrid interrupted-continuous suturing technique yielded higher immediate and 6-week primary patency rates for RCF. The hybrid interrupted-continuous suturing technique may improve anastomotic compliance and reduce the narrowing and puckering that can occur on suture tightening in small-caliber vessels. Based on these findings, consideration should be given to performing hybrid interrupted-continuous anastomoses for RCFs.

Central venous catheters (CVC) remain a mainstay of vascular access particularly for incident patients, but lead to central vein stenosis (CVS) in up to 1 in 6 patents. This often leads to establishing dialysis access in the groin which in turn may result in development of CVS in the lower body, although this is poorly reported. The HeRO device was designed to address CVS by bypassing the stenosed veins with a nitinol-reinforced silicone tube into the right atrium, which acts as an outflow conduit attached to an arterial inflow. The efficacy and safety of the HeRO device in the upper limb is well established, but there is no data on its use in the lower limb. We describe 2 cases of HeRO in the lower limb, one primary and one secondary, which remain in use. Lower limb HeRO is feasible in the lower limb and can work well either as de novo (to achieve vascular access) or as a salvage procedure (to maintain vascular access).

Traditional contrast-enhanced methods for scanning blood vessels using magnetic resonance imaging (MRI) or CT carry potential risks for patients with advanced kidney disease. Ferumoxytol is a superparamagnetic iron oxide nanoparticle preparation that has potential as an MRI contrast agent in assessing the vasculature. Twenty patients with advanced kidney disease requiring aorto-iliac vascular imaging as part of pre-operative kidney transplant candidacy assessment underwent ferumoxytol-enhanced magnetic resonance angiography (FeMRA) between December 2015 and August 2016. All scans were performed for clinical indications where standard imaging techniques were deemed potentially harmful or inconclusive. Image quality was evaluated for both arterial and venous compartments. First-pass and steady-state FeMRA using incremental doses of up to 4 mg/kg body weight of ferumoxytol as intravenous contrast agent for vascular enhancement was performed. Good arterial and venous enhancements were achieved, and FeMRA was not limited by calcification in assessing the arterial lumen. The scans were diagnostic and all patients completed their studies without adverse events. Our preliminary experience supports the feasibility and utility of FeMRA for vascular imaging in patients with advanced kidney disease due for transplant listing, which has the advantages of obtaining both arteriography and venography using a single test without nephrotoxicity. • Evaluation of vascular disease is important in planning kidney transplantation. • Standard vascular imaging methods are often problematic in kidney disease patients. • FeMRA has the advantage of arteriography and venography in a single test. • FeMRA is safe and non-nephrotoxic. • FeMRA is not limited by arterial calcification.

Objectives: To describe the UK and Ireland experience of the Haemodialysis Reliable Outflow graft in complex vascular access. Design: Observational, multi-centre case series. Methods: Data from any patient undergoing Haemodialysis Reliable Outflow graft were collected from eight UK and one Irish centre. Any Haemodialysis Reliable Outflow procedure between July 2013 and May 2016 was included. Demographics, primary and secondary patency rates, and complications were analysed. Results: A total of 52 patients underwent Haemodialysis Reliable Outflow graft insertion. Median age was 55 (20–86) years, 24 (46%) were male and 66% were Caucasian. Median follow-up was 290 (10–966) days and patient survival was 41/52 (79%). In total, 48 procedures were in the upper limb with 39 using the brachial artery as inflow (75%). The internal jugular vein and subclavian vein were most frequently used as access for outflow insertion. Primary patency rates at 6, 12, and 24 months were 51.2% (95% confidence interval, 38.8%–67.4%), 40.9% (95% confidence interval, 28.7%–58.2%), and 33.4% (95% confidence interval, 21.3%–52.5%), respectively. Secondary patency rates at 6, 12, and 24 months were 84.8% (95% confidence interval, 75%–95.9%), 76.5% (95% confidence interval, 64.5%–90.6%), and 70.6% (95% confidence interval, 56%–88.9%), respectively. There were 65 surgical and 49 radiological interventions resulting in 2.30 interventions per year to retain patency. Complications included four infections and two episodes of steal syndrome. Conclusion: The Haemodialysis Reliable Outflow graft provides acceptable 12-month secondary patency rates and acceptable complication rates in a UK and Ireland multi-centre series of complex access patients. Haemodialysis Reliable Outflow should be considered in patients with central pathology as a potential alternative to lower limb grafts and long-term central venous catheters.

Purpose Central vein stenosis (CVS) and line infection are well-recognized complications of tunnelled central venous catheters (TCVCs) in patients on haemodialysis. The aim of this study was to evaluate any relationship between CVS and line infection. Methods Analysis of 500 consecutive patients undergoing TCVC insertion was undertaken. Data were collected on patient demographics, details of line insertion and duration, culture-proven bacteraemia and presence of symptomatic CVS. Logistic regression analysis was used to determine risk factors for CVS and bacteraemia. Results Mean patient age was 59.0 years (range: 17-93). Mean number of catheter days was 961.1 ± 57.6 per TCVC; 39.4% of TCVCs were associated with culture-proven bacteraemia and 23.6% developed symptomatic CVS. Bacteraemia and CVS were inevitable complications of all TCVCs. The time to symptomatic CVS was longer in patients with bacteraemia than without (1230.91 ± 101.29 vs. 677.49 ± 61.59 days, pConclusions Our results suggest that early line infection may be protective against CVS. Alternatively, there may be two distinct predisposition states for CVS and line infection. Further studies are needed to confirm our association and investigate causation.

Background The aim of this study was to evaluate the relationship between Qa, cardiovascular parameters and symptomatic cardiac disease. Methods A prospective cohort study of 100 patients dialysing via an arteriovenous fistula (AVF) was performed. Qa was measured using pulsed Doppler ultrasound. Cardiovascular parameters were measured using thoracic bioimpedance technique (Medis, GmbH). Measurement of cardiovascular parameters was undertaken pre- and post-occlusion of the AVF. Results Mean age was 57.1 years (range: 19-83); 51% male. Mean values pre-occlusion: mean arterial blood pressure (MABP) 89.6 ± 16.9 mmHg; stroke volume index (SVI) 39.3 ± 4.6 mL; cardiac index (CI) 3.7 ± 0.8 L/min/m2; systemic vascular resistance index (SVRI) 585.5 ± 67.8 dyn/sec/cm−5/m2; oxygen delivery (DO2I) 607.1 ± 116.8 mL/min/m2. A total of 12% of patients had CI>4.5 L/min/m2 pre-occlusion. There was no difference in heart rate (HR), MABP and SVI following occlusion of AVF. Mean CI reduced post-AVF occlusion (∆CI: -0.42 L/min/m2; p2I (∆ DO2I: 45.5 mL/min/m2; p−5/m2; p2000 mL/min (-2.79 ± 0.34 vs. -0.24 ± 0.48 L/min/m2; p2; NHYA 2: -0.3 ± 0.7 L/min/m2; NYHA 3: -0.7 ± 1.0 L/min/m2; p = 0.06). Conclusions The relationship between AVF blood flow, cardiac output and symptomatic cardiac disease is complex. Occlusion of an AVF leads to reduced cardiac output and improved oxygen delivery, even in asymptomatic patients. This difference is most marked in patients with high-flow AVF (>2000 mL/min). High-flow AVF with large ∆CI may lead to high cardiac output state, which is reversible on occlusion of the AVF.

Background The modality by which haemodialysis (HD) is delivered [arteriovenous fistula (AVF), arteriovenous graft (AVG) or central venous catheter (CVC)] varies widely and is influenced by clinical evidence, patient factors and the prevailing service configuration. The aim of this study was to determine the outcome and impact of access strategy on patient outcome by mapping out the HD journey in a cohort of incident patients. Methods A 2-year cohort of consecutive incident HD patients from the point of referral for first dialysis access to completion of the first 365 days of HD was prospectively reviewed. Data were sought on access type; radiological, surgical and other access-related activity; bacteraemic events; admission rates and cumulative financial cost. Results A total of 144 patients started RRT for the first time with HD over the 2-year period. All were followed up to 1 year after starting HD, generating a total of 47 753 observed HD days. Activity prior to starting HD for the full cohort was found to average 0.92 arteriovenous (AV) access creation procedures, 0.40 CVC insertions, 0.14 interventional radiology procedures and 0.41 ultrasound examinations per patient. The small number of patients who started on an AVG had a tendency towards higher pre-HD surgical and imaging activity than those who started on an AVF or CVC. Activity after starting HD varied greatly with the access type used at the start of HD, with AVF patients experiencing less hospitalization, procedure and imaging activity and financial costs compared with those who start HD with a CVC. Patients who started on an AVG had a tendency towards lower surgical activity rates and financial costs than those who started on a CVC. Conclusions Providing, maintaining and dealing with the complications of HD vascular access places a significant burden of activity that is shared across nephrology, surgery and imaging services. A well-functioning AVF is associated with the lowest burden, whereas a failed AVF or CVC access is associated with the highest burden. Patient journeys are shaped by the vascular access that they use and we suggest that the contemporary pursuit of HD access should focus on delivering personalized access solutions.