Publications by authors named "Francis Calder"

27 Publications

  • Page 1 of 1

A multicenter randomized controlled trial indicates that paclitaxel-coated balloons provide no benefit during angioplasty of arteriovenous fistulas.

Kidney Int 2021 Mar 26. Epub 2021 Mar 26.

MBBS, PhD, King's College London/ Guy's and St Thomas' NHS Foundation Trust. Electronic address:

The role of paclitaxel-coated balloons has been established in the coronary and peripheral arterial circulations with recent interest in the use of paclitaxel-coated balloons to improve patency rates following angioplasty of arteriovenous fistulas. To assess the efficacy of paclitaxel-coated angioplasty balloons to prolong the survival time of target lesion primary patency in arteriovenous fistulas, we designed an investigator-led multi-center randomized controlled trial with follow up time variable for a minimum of one year. Patients with an arteriovenous fistula who were undergoing an angioplasty for a clinical indication were included but patients with one or more lesions outside the treatment segment were excluded. Following successful treatment with a high-pressure balloon, 212 patients were randomized. In the intervention arm, the second component was insertion of a paclitaxel-coated balloon. In the control arm, an identical procedure was followed, but using a standard balloon. The primary endpoint was time to loss of clinically-driven target lesion primary patency. Primary analysis showed no significant evidence for a difference in time to end of target lesion primary patency between groups: hazard ratio 1.18 with a 95% confidence interval of 0.78 to 1.79. There were no significant differences for any secondary outcomes, including patency outcomes and adverse events. Thus, our study demonstrated no evidence that paclitaxel-coated balloons provide benefit, following standard care high-pressure balloon angioplasty, in the treatment of arteriovenous fistulas. Hence, in view of the benefit suggested by other trials, the role of paclitaxel-coated angioplasty balloons remains uncertain.
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http://dx.doi.org/10.1016/j.kint.2021.02.040DOI Listing
March 2021

Surgeons Are Not Pilots: Is the Aviation Safety Paradigm Relevant to Modern Surgical Practice?

J Surg Educ 2021 Feb 9. Epub 2021 Feb 9.

Guy's and St. Thomas' NHS Foundation Trust; King's College London, London, England.

Error in surgery is common, although not always consequential. Surgical outcomes are often compared to safety data from commercial aviation. This industry's performance is frequently referenced as an example of high-reliability that should be reproduced in clinical practice. Consequently, the aviation-surgery analogy forms the conceptual framework for much patient safety research, advocating for the translation of aviation safety tools to the healthcare setting. Nevertheless, overuse or incorrect application of this paradigm can be misleading and may result in ineffective quality improvement interventions. This article discusses the validity and relevance of the aviation-surgery comparison, providing the necessary context to improve its application at the bedside. It addresses technical and human factors training, as well as more novel performance domains such as professional culture and optimization of operators' condition. These are used to determine whether the aviation-surgery analogy is a valuable source of cross-professional learning or simply another safety cliché.
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http://dx.doi.org/10.1016/j.jsurg.2021.01.016DOI Listing
February 2021

Silent and dangerous: catheter-associated right atrial thrombus (CRAT) in children on chronic haemodialysis.

Pediatr Nephrol 2021 May 30;36(5):1245-1254. Epub 2020 Oct 30.

Department of Paediatric Nephrology, Evelina London Children's Hospital, London, SE1 7EH, UK.

Background: Catheter-associated right atrial thrombus (CRAT) is a recognised complication of central venous catheter (CVC) use for haemodialysis (HD) patients.

Methods: This was a single-centre retrospective longitudinal observational study of consecutive children aged 6 months-18 years over a 7-year period receiving in-centre chronic HD. Echocardiograms as per routine cardiac surveillance were performed 6 months or earlier given clinical concerns.

Results: Sixty-five children, 36 boys (55.4%), median (IQR) age 11.8 (5.3, 14.7) years, received HD for kidney failure with replacement therapy (KFRT). Initial modality was HD in 45 (69.2%), with CVC as initial access in 42 (93.3%) and AVF in 3 (6.7%); in the remaining 20 (30.8%) patients PD was the initial modality before switching to HD. Seven of 65 (10.8%) developed CRAT at median 2 (0.8, 8.4) months from CVC insertion, with one CRAT detected 3 days following insertion. One child had 2 episodes of CRAT and one additionally thrombosed their AVF. No patient had an underlying primary kidney disease associated with a pro-thrombotic state. Those with CRAT were younger, had more frequent CVC change and received dialysis for longer duration compared to those with no CRAT. Six episodes of CRAT (75%) received anticoagulation therapy. Infective complications were observed in 25% and catheter malfunction in 50%. Five CRAT episodes (62.5%) resulted in CVC loss. One patient died after a haemorrhagic complication of anticoagulation and sepsis, and another developed life-threatening superior vena cava obstruction syndrome. Overall mortality 14% (1/7).

Conclusions: This is the first report of CRAT in a paediatric HD population. There was ~ 11% incidence of CRAT in patients receiving chronic HD detected by surveillance echocardiography. Although frequently asymptomatic, CRAT is associated with serious sequelae. Anticoagulation and surveillance with expert echocardiography remain mainstays of management. Graphical abstract.
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http://dx.doi.org/10.1007/s00467-020-04743-9DOI Listing
May 2021

Update on the creation and maintenance of arteriovenous fistulas for haemodialysis in children.

Pediatr Nephrol 2020 Oct 15. Epub 2020 Oct 15.

"Mitera" Children's Hospital, Maroussi, Athens, Greece.

Arteriovenous fistulas (AVFs) are widely used for haemodialysis (HD) in adults with stage 5 chronic kidney disease (CKD 5) and are generally considered the best form of vascular access (VA). The 'Fistula First' initiative in 2003 helped to change the culture of VA in adults. However, this cultural change has not yet been adopted in children despite the fact that a functioning AVF is associated with lower complication rates and longer access survival than a central venous line (CVL). For children with CKD 5, especially when kidney failure starts early in life, there is a risk that all VA options will be exhausted. Therefore, it is essential to develop long-term strategies for optimal VA creation and maintenance. Whilst AVFs are the preferred VA in the paediatric population on chronic HD, they may not be suitable for every child. Recent guidelines and observational data in the paediatric CKD 5 population recommend switching from a 'Catheter First' to 'Catheter Last' approach. In this review, recent evidence is summarized in order to promote change in current practices.
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http://dx.doi.org/10.1007/s00467-020-04746-6DOI Listing
October 2020

UK renal transplant outcomes in low and high BMI recipients: the need for a national policy.

J Nephrol 2020 Apr 3;33(2):371-381. Epub 2019 Oct 3.

Department of Transplantation, Guy's Hospital, Guy's and St Thomas' NHS Foundation Trust, Great Maze Pond, London, SE1 9RT, UK.

Introduction: We assessed the effect of recipient body mass index (BMI) on the outcomes of renal transplantation and the management of obese patients with end-stage renal disease across the UK.

Methods: We analyzed data of 25539 adult renal transplants (2007-2016) from the UK Transplant Registry. Patients were divided in BMI groups [underweight: < 18.5, normal: 18.5-24.9 (reference group), overweight: 25-29.9, class I obese: 30-34.9, class II/III obese: ≥ 35]. We also conducted a national survey of all UK renal transplant centers on the influence of BMI on decisions regarding management of renal transplant candidates.

Results: BMI ≥ 25 was an independent risk factor for delayed graft function and primary non-function (p ≤ 0.001). Underweight (p = 0.001), class I obese (p = 0.017) and class II/III obese recipients (p < 0.001) had poorer graft survival, however, 5- and 10-year graft survival rates were good. Patient survival was shorter for underweight recipients (p < 0.001) and longer for overweight (p = 0.028) and class I obese recipients (p = 0.013). The national survey revealed significant variability among transplant centers in BMI threshold for listing patients on transplant waiting list and limited support with conservative or surgical procedures for weight control.

Conclusions: Obesity alone should not be a barrier for renal transplantation. A national strategy is required to give all patients equal chances in transplantation.
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http://dx.doi.org/10.1007/s40620-019-00654-7DOI Listing
April 2020

An Implanted Blood Vessel Support Device for Arteriovenous Fistulas: A Randomized Controlled Trial.

Am J Kidney Dis 2020 01 22;75(1):45-53. Epub 2019 Aug 22.

Department of Nephrology and Transplantation, Guy's and St Thomas' NHS Foundation Trust, London.

Rationale & Objective: Reducing turbulent blood flow through dialysis arteriovenous fistulas (AVFs) and radial stretching of their venous wall may attenuate hyperplasia and stenosis and improve AVF outcomes in hemodialysis patients. The goal of this study was to evaluate the safety and efficacy of the VasQ implant, which intervenes on these mechanisms by physically supporting the surgical arteriovenous anastomosis.

Study Design: Prospective, randomized, controlled, multicenter study.

Settings & Participants: 40 consecutive patients with kidney failure referred for creation of a brachiocephalic fistula in 4 vascular access centers in the United Kingdom and Israel.

Interventions: AVF surgical creation with placement of the VasQ implant (treatment) versus AVF placement without the implant (control).

Outcomes: Safety assessed as percentage of severe device-related adverse events was the primary outcome. Secondary outcomes were efficacy assessments including: (1) AVF maturation at 3 months, defined as cephalic vein diameter≥5mm and flow≥500mL/min; (2) functional cumulative patency, defined as successful 2-needle cannulation for two-thirds or more of all dialysis runs for 1 month in study participants receiving dialysis; (3) cephalic vein diameter and blood flow; and (4) primary and cumulative patency at 6 months.

Results: No severe device-related adverse events were observed. There was no significant difference in maturation at 3 months or primary patency at 6 months between treatment and control (85% vs 80% and 80% vs 66%). Significantly larger vein luminal diameters were observed in the treatment group versus controls at 3 and 6 months (8.27±2.2 vs 6.69±1.8mm [P=0.03] and 9.6±2.5 vs 7.56±2.7mm [P=0.03]). Functional patency at 6 months was significantly greater in the treatment group (100% vs 56% [P = 0.01]).

Limitations: Small sample size, limited power for secondary end points.

Conclusions: No safety signals were detected for the VasQ external support of brachiocephalic AVFs. Higher functional patency and vein luminal diameters were achieved with the device at 3 and 6 months. VasQ may safely intervene on mechanisms associated with the disturbed hemodynamic profile in the juxta-anastomotic region.

Funding: Funded by Laminate Medical Technologies Ltd.

Trial Registration: Registered at ClinicalTrials.gov with study number NCT02112669.
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http://dx.doi.org/10.1053/j.ajkd.2019.05.023DOI Listing
January 2020

Factors associated with outcome after successful radiological intervention in arteriovenous fistulas: A retrospective cohort.

J Vasc Access 2019 Nov 14;20(6):716-724. Epub 2019 May 14.

Renal, Transplant and Urology Directorate, Guy's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK.

Introduction: Arteriovenous fistulas are the best form of vascular access for haemodialysis. A radiological balloon angioplasty is the standard treatment for a clinically relevant stenosis, but the recurrence rate is high. Data on factors associated with recurrence are limited.

Methods: A single centre, retrospective analysis was performed for 124 consecutive patients who had successful interventions for dysfunctional arteriovenous fistulae, to examine factors associated with post-intervention patency. Follow-up was at least 1 year for all patients. Variables associated with primary and cumulative patency were pre-specified and assessed using both un-adjusted (univariate) and adjusted Cox proportional hazards models. Analysis was repeated for a subgroup of 80 patients with a single lesion only in order to examine the potential effects of stenotic lesion characteristics on patency.

Results: Factors found to have a significant association with poorer outcomes (less time to loss of patency) included thrombosis at the time of intervention and a history of previous intervention. Fistula age (log days) was significantly associated with better outcomes (greater time to loss of patency). Non-white ethnicity, lesion length, and patient age were also significantly associated with accelerated loss of patency.

Discussion: The factors we have identified as linked to poor outcome may help to identify patients in whom a balloon angioplasty is unlikely to provide a durable outcome. This may prompt exploring alternative treatment or dialysis options at an early stage.
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http://dx.doi.org/10.1177/1129729819845991DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6856953PMC
November 2019

Vascular access in children requiring maintenance haemodialysis: a consensus document by the European Society for Paediatric Nephrology Dialysis Working Group.

Nephrol Dial Transplant 2019 10;34(10):1746-1765

Mitera Children's Hospital, Athens, Greece.

Background: There are three principle forms of vascular access available for the treatment of children with end stage kidney disease (ESKD) by haemodialysis: tunnelled catheters placed in a central vein (central venous lines, CVLs), arteriovenous fistulas (AVF), and arteriovenous grafts (AVG) using prosthetic or biological material. Compared with the adult literature, there are few studies in children to provide evidence based guidelines for optimal vascular access type or its management and outcomes in children with ESKD.

Methods: The European Society for Paediatric Nephrology Dialysis Working Group (ESPN Dialysis WG) have developed recommendations for the choice of access type, pre-operative evaluation, monitoring, and prevention and management of complications of different access types in children with ESKD.

Results: For adults with ESKD on haemodialysis, the principle of "Fistula First" has been key to changing the attitude to vascular access for haemodialysis. However, data from multiple observational studies and the International Paediatric Haemodialysis Network registry suggest that CVLs are associated with a significantly higher rate of infections and access dysfunction, and need for access replacement. Despite this, AVFs are used in only ∼25% of children on haemodialysis. It is important to provide the right access for the right patient at the right time in their life-course of renal replacement therapy, with an emphasis on venous preservation at all times. While AVFs may not be suitable in the very young or those with an anticipated short dialysis course before transplantation, many paediatric studies have shown that AVFs are superior to CVLs.

Conclusions: Here we present clinical practice recommendations for AVFs and CVLs in children with ESKD. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system has been used to develop and GRADE the recommendations. In the absence of high quality evidence, the opinion of experts from the ESPN Dialysis WG is provided, but is clearly GRADE-ed as such and must be carefully considered by the treating physician, and adapted to local expertise and individual patient needs as appropriate.
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http://dx.doi.org/10.1093/ndt/gfz011DOI Listing
October 2019

Endovascular intervention in the maintenance and rescue of paediatric arteriovenous fistulae for hemodialysis.

Pediatr Nephrol 2019 04 27;34(4):723-727. Epub 2018 Nov 27.

Guy's and St. Thomas' NHS Foundation Trust, London, UK.

Background: Arteriovenous fistulae (AVF) provide superior primary vascular access for children on chronic dialysis compared to central venous catheters (CVC). However, AVFs inevitably develop complications and will require some intervention to maintain long-term functional patency.

Methods: We report an 'endovascular-first' approach to the maintenance and rescue of paediatric AVFs. Thirty interventions targeting 46 lesions in 18 children (median age 11 years [range 5-17]) were performed. Sixty-eight percent of the AVFs were brachio-cephalic fistulae, 26% brachio-basilic fistulae and 5% radio-cephalic fistulae. Immediate functional success was 86% with good dialysis adequacy (mean urea reduction ratio > 70%) at 3 months post procedure.

Results: There was one significant complication, consisting of an AVF rupture which was managed with a covered stent.

Conclusions: Repeated interventions may be necessary to maintain AVF patency and avoid central venous catheters. This is the largest series reported to date.
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http://dx.doi.org/10.1007/s00467-018-4143-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6394687PMC
April 2019

Insights in Transplanting Complex Pediatric Renal Recipients With Vascular Anomalies.

Transplantation 2017 10;101(10):2562-2570

1 Department of Transplant Surgery, Guy's and Thomas', Evelina Children's London and Great Ormond Street Hospitals NHS Trust, London, United Kingdom. 2 Department of Paediatric Anaesthetics and Intensive Care, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom. 3 Department of Paediatric Interventional Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom. 4 Department of Vascular Surgery, Royal Free Hospital, London, United Kingdom. 5 Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom.

Background: Children with end-stage kidney disease may have coexisting iatrogenic or congenital vascular anomalies making transplantation difficult. We describe our approach in 5 recipients with vascular anomalies and significant comorbidities, including one case of blood group incompatibility.

Methods: Five children aged 3 to 17 years (median, 7 years), weighing 14 to 34 kg (median, 18 kg) kg of whom 4 had occluded inferior vena cava or iliac veins and 2 had previous complex vascular reconstructions before transplantation for midaortic syndrome and multiple aortic aneurysms, respectively underwent renal transplantation. To establish implant feasibility surgery was commenced in 2 recipients before the donor surgery.

Results: There was 4 (80%) of 5 patient survival after 1 death from sepsis (with a functioning graft) and 2 cases of delayed graft function. At the latest median follow-up of 19 months, there was 100% (death-censored) renal allograft survival with estimated glomerular filtration rates (mL/min per 1.73 m) of 43 to 72 (median, 55).

Conclusions: We conclude that major vascular anomalies do not necessarily preclude transplantation in complex pediatric patients and that surgical exploration of the recipient before commencing the donor surgery is valuable where feasibility and safety are uncertain. In addition, we have developed a novel classification system of congenital vascular abnormalities and propose its use in complex pediatric transplantation.
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http://dx.doi.org/10.1097/TP.0000000000001640DOI Listing
October 2017

A dedicated vascular access clinic for children on haemodialysis: Two years' experience.

Pediatr Nephrol 2016 12 7;31(12):2337-2344. Epub 2016 Aug 7.

Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.

Background: Arteriovenous fistula (AVF) formation for long-term haemodialysis in children is a niche discipline with little data for guidance. We developed a dedicated Vascular Access Clinic that is run jointly by a transplant surgeon, paediatric nephrologist, dialysis nurse and a clinical vascular scientist specialised in vascular sonography for the assessment and surveillance of AVFs. We report the experience and 2-year outcomes of this clinic.

Methods: Twelve new AVFs were formed and 11 existing AVFs were followed up for 2 years. All children were assessed by clinical and ultrasound examination.

Results: During the study period 12 brachiocephalic, nine basilic vein transpositions and two radiocephalic AVFs were followed up. The median age (interquartile range) and weight of those children undergoing new AVF creation were 9.4 (interquartile 3-17) years and 26.9 (14-67) kg, respectively. Pre-operative ultrasound vascular mapping showed maximum median vein and artery diameters of 3.0 (2-5) and 2.7 (2.0-5.3) mm, respectively. Maturation scans 6 weeks after AVF formation showed a median flow of 1277 (432-2880) ml/min. Primary maturation rate was 83 % (10/12). Assisted maturation was 100 %, with two patients requiring a single angioplasty. For the 11 children with an existing AVF the maximum median vein diameter was 14.0 (8.0-26.0) mm, and the median flow rate was 1781 (800-2971) ml/min at a median of 153 weeks after AVF formation. Twenty-two AVFs were used successfully for dialysis, a median kt/V of 1.97 (1.8-2.9), and urea reduction ratio of 80.7 % (79.3-86 %) was observed. One child was transplanted before the AVF was used.

Conclusions: A multidisciplinary vascular clinic incorporating ultrasound assessment is key to maintaining young children on chronic haemodialysis via an AVF.
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http://dx.doi.org/10.1007/s00467-016-3428-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5118405PMC
December 2016

Improving outcomes in dialysis fistulae.

Lancet 2016 Sep 1;388(10049):1029-1030. Epub 2016 Aug 1.

Department of Transplantation, Nephrology, and Urology, Guy's Hospital, London SE1 9RT, UK.

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http://dx.doi.org/10.1016/S0140-6736(16)31230-2DOI Listing
September 2016

Paclitaxel-coated balloon fistuloplasty versus plain balloon fistuloplasty only to preserve the patency of arteriovenous fistulae used for haemodialysis (PAVE): study protocol for a randomised controlled trial.

Trials 2016 May 12;17(1):241. Epub 2016 May 12.

MRC Centre for Transplantation, King's College London, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK.

Background: The initial therapy for a stenosis in an arteriovenous fistula used for haemodialysis is radiological balloon dilatation or angioplasty. The benefit of angioplasty is often short-lived, intervention-free survival is reported to be 40-50 % at 1 year. Previous small studies and observational data suggest that paclitaxel-coated balloons may be of benefit in improving outcomes after fistuloplasty of stenotic arteriovenous fistulae.

Methods/design: We have designed a multicentre, double-blind randomised controlled trial to test the superiority of paclitaxel-coated balloons for preventing restenosis after fistuloplasty in patients with a native arteriovenous fistula. Two hundred and eleven patients will be followed up for a minimum of 1 year. Inclusion criteria include a clinical indication for a fistuloplasty, an access circuit that is free of synthetic graft material or stents, and a residual stenosis of 30 % or less after plain balloon fistuloplasty. Exclusion criteria include a synchronous venous lesion in the same access circuit, location of the stenosis central to the thoracic inlet or a thrombosed access circuit at the time of treatment. The primary endpoint is time to end of target lesion primary patency. This is defined as a clinically-driven radiological or surgical re-intervention at the treatment segment, thrombosis that includes the treatment segment, or abandonment of the access circuit due to an inability to re-treat the treatment segment. Secondary endpoints include angiographic late lumen loss, time to end of access circuit cumulative patency, the total number of interventions, and quality of life. The trial is funded by the National Institute for Health Research.

Discussion: We anticipate that this trial will provide rigorous data that will determine the efficacy of additional paclitaxel-coated balloon fistuloplasty versus plain balloon fistuloplasty only to preserve the patency of arteriovenous fistulae used for haemodialysis.

Trial Registration: ISRCTN14284759 . Registered on 28 October 2015.
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http://dx.doi.org/10.1186/s13063-016-1372-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866413PMC
May 2016

Do we need a different organ allocation system for kidney transplants using donors after circulatory death?

BMC Nephrol 2014 May 22;15:83. Epub 2014 May 22.

UCL Centre for Nephrology, Royal Free hospital, London, UK.

Background: There is no national policy for allocation of kidneys from Donation after circulatory death (DCD) donors in the UK. Allocation is geographical and based on individual/regional centre policies. We have evaluated the short term outcomes of paired kidneys from DCD donors subject to this allocation policy.

Methods: Retrospective analysis of paired renal transplants from DCD's from 2002 to 2010 in London. Cold ischemia time (CIT), recipient risk factors, delayed graft function (DGF), 3 and 12 month creatinine) were compared.

Results: Complete data was available on 129 paired kidneys.115 pairs were transplanted in the same centre and 14 pairs transplanted in different centres. There was a significant increase in CIT in kidneys transplanted second when both kidneys were accepted by the same centre (15.5 ± 4.1 vs 20.5 ± 5.8 hrs p<0.0001 and at different centres (15.8 ± 5.3 vs. 25.2 ± 5.5 hrs p=0.0008). DGF rates were increased in the second implant following sequential transplantation (p=0.05).

Conclusions: Paired study sequential transplantation of kidneys from DCD donors results in a significant increase in CIT for the second kidney, with an increased risk of DGF. Sequential transplantation from a DCD donor should be avoided either by the availability of resources to undertake simultaneous procedures or the allocation of kidneys to 2 separate centres.
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http://dx.doi.org/10.1186/1471-2369-15-83DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4035739PMC
May 2014

A comparison of the outcomes of one-stage and two-stage brachiobasilic arteriovenous fistulas.

J Vasc Surg 2013 Nov 28;58(5):1300-4. Epub 2013 Jun 28.

Renal Department, King's College Hospital, London, United Kingdom; Department of Nephrology and Transplantation, Guy's Hospital, London, United Kingdom. Electronic address:

Objective: The brachiobasilic arteriovenous fistula (BBAVF) can be formed in one or two stages. This study examined the failure rates and functional patencies of one-stage vs two-stage brachiobasilic transposition fistulas to compare the two surgical techniques.

Methods: We retrospectively identified all the patients who underwent BBAVF access surgery at King's College Hospital between January 1, 2009, and December 31, 2011 (3 years). Patients were divided into two groups according to one-stage or two-stage procedure. All patients were seen in the access clinic 4 to 6 weeks postoperatively, and their fistulas were scanned (duplex). The surveillance of fistulas consists of duplex scans every 6 months to assess volume flow.

Results: During the study interval, 149 brachiobasilic transpositions (65 one-stage and 84 two-stage) were performed in 141 patients. Patients undergoing the two-stage procedure had a smaller mean preoperative vein diameter (4.0 ± 1.1 vs 3.6 ± 1.3 mm; P = .041) and tended to be older (58 ± 15 vs 63 ± 15 years; P = .062). Mean overall follow-up was 559 ± 333 days. There was no difference in primary failure between the two groups (45% vs 42%; P = .718). At 1 year, the two-stage BBAVFs had significantly better primary (71% vs 87%; P = .034), assisted primary (77% vs 95%; P = .017), and secondary functional (79% vs 95%; P = .026) patencies. The same applied to 2-year primary (53% vs 75%; P = .034), assisted primary (57% vs 77%; P = .017), and secondary functional (57% vs 77%; P = .026) patencies. Multivariate Cox regression showed that the one-stage procedure was 3.2 times more likely to fail (P = .028). Men were 2.7 times more likely to lose their access (P = .054).

Conclusions: This study describes a large series of BBAVFs and makes an extensive comparison between the one-stage and two-stage operations. Significantly improved overall functional patency is demonstrated for the two-stage operation.
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http://dx.doi.org/10.1016/j.jvs.2013.05.030DOI Listing
November 2013

Nephrectomy for the failed renal allograft in children: predictors and outcomes.

Pediatr Nephrol 2013 Aug 19;28(8):1299-305. Epub 2013 Apr 19.

Renal Unit, Great Ormond Street Hospital for Children, Great Ormond Street, London, WC1N 3JH, UK.

Background: There are no guidelines for the removal of a failed renal allograft, and its impact on subsequent dialysis and retransplantation has not yet been described.

Methods: We performed a 10-year review of allograft failure to study the factors that determined an outcome of transplant nephrectomy and choice of subsequent renal replacement therapy in children with or without nephrectomy.

Results: A total of 34 children developed graft failure over the 10-year study period, of whom 18 (53 %) required transplant nephrectomy. The median graft survival was 1.1 (range 0.2-10.6) versus 7.5 (1.5-15.0) years in the nephrectomy and non-nephrectomy groups, respectively (p = 0.011). Children with graft failure within 1 year of transplantation were four-fold more likely to require transplant nephrectomy than those with graft failure after 1 year (p = 0.04). Renal biopsy performed at ≤ 8 weeks prior to graft loss showed Banff grade II acute rejection in 13 of the 18 children who required subsequent nephrectomy versus three of the 13 children who did not need nephrectomy (p = 0.01). Inflammation (fever, graft tenderness and raised C-reactive protein (CRP) in the 2 weeks preceding graft failure) was seen in 66 % of nephrectomized children, but not in any in the non-nephrectomy group (p = 0.0003 for CRP between groups). Banff II rejection, an inflammatory response and the time post-transplantation significantly and independently predicted the outcome of nephrectomy (p = 0.008, R (2) = 67 %). Human leukocyte antigen (HLA) antibody levels after graft failure were higher in the nephrectomy group (p = 0.0003), but there was no difference between groups in terms of the presence or class of donor-specific antibodies. Of the children with graft failure, 82 % required dialysis (61 % hemodialysis) and 35 % have to date been successfully retransplanted.

Conclusions: Children with Banff II rejection, an inflammatory response and early graft loss are more likely to require transplant nephrectomy. Nephrectomy may be associated with higher circulating HLA antibody levels.
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http://dx.doi.org/10.1007/s00467-013-2477-9DOI Listing
August 2013

Clinically significant peripancreatic fluid collections after simultaneous pancreas-kidney transplantation.

Transplantation 2013 May;95(10):1263-9

Department of Transplant Surgery, MRC Centre for Transplantation, Guy's Hospital, Great Maze Pond, London, United Kingdom.

Background: Peripancreatic fluid collections (PPFC) are a serious complication after simultaneous pancreas-kidney transplantation (SPKTx).

Methods: Retrospective study for all 223 SPKTx performed from December 8, 1996, to October 10, 2011, to evaluate the risk factors (RF) and impact of PPFCs on outcomes was conducted.

Results: Clinically significant PPFCs were seen in 36 (16%) cases, all within 3 months after transplantation. Radiologic drainage resolved 2 (6%) cases, and 34 required laparotomy (mean [SD], 4 [7]). Compared with the non-PPFC group (n=186), the PPFC group had similar patient and total kidney graft survivals but significantly lower total pancreas survival (68% vs. 85%) and greater incidence of infections (75% vs. 46%, all P<0.05) at 5 years. PPFCs were associated with early graft pancreatitis in 18 (50%), pancreatic fistula in 20 (56%, 9 with obvious duodenal stump leak) and infection in the collection in 20 (56%) cases. Comparison of PPFCs with pancreas graft loss to the PPFCs with surviving grafts showed that the incidence of pancreatic fistula was greater in the former (90% pancreas graft loss vs. 42% pancreas graft survival, P<0.01). Binary logistic regression analysis of RF for developing PPFC showed a donor age >30 years to be significant (P=0.03; odds ratio, 3.4; confidence interval, 1.1-10.5) and a trend of association with donor body mass index >30 and pancreas cold ischemia time greater than 12 hr.

Conclusions: PPFCs are associated with significant reduction in pancreas allograft survival and impact resource use. Donor age >30 years is a significant RF for their development. PPFCs associated with pancreatic fistula carry a greater risk for pancreas graft loss.
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http://dx.doi.org/10.1097/TP.0b013e318289c978DOI Listing
May 2013

Practical aspects of arteriovenous fistula formation in the pediatric population.

Pediatr Nephrol 2013 Jun 27;28(6):885-93. Epub 2012 Oct 27.

Renal Transplant & Vascular Access Surgery, Guy's and The Evelina Hospitals, Great Ormond Street Hospital, London, London, UK.

The principle of "Fistula First" for hemodialysis has been widely adopted among adults with end-stage renal failure (ESRF). UK national targets aim to have 85 % of prevalent patients using permanent access (arteriovenous fistula or graft). Currently, hemodialysis in children relies heavily on central venous catheters (CVC). However, there is significant evidence that arteriovenous fistulae (AVF) are preferable for long-term dialysis in the pediatric population. We describe the principles of fistula formation including pre-operative work-up, surgical techniques for AVF creation, and post-operative monitoring.
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http://dx.doi.org/10.1007/s00467-012-2328-0DOI Listing
June 2013

A comparison of arteriovenous fistulas and central venous lines for long-term chronic haemodialysis.

Pediatr Nephrol 2013 Feb 6;28(2):321-6. Epub 2012 Oct 6.

Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Trust, London, WC1N 3JH, UK.

Background: Despite the Fistula First initiative there is still reluctance to use arteriovenous fistulas (AVF) for chronic haemodialysis (HD) in children. Our aim was to compare outcomes of AVFs and central venous lines (CVL) in children on chronic HD in a centre where AVF is the primary choice for vascular access.

Patients And Methods: This was a retrospective case notes analysis of access complications, dialysis adequacy and laboratory outcomes in children who underwent dialysis for at least a year by AVF (n = 20, median age 14.2 years, range (2.9-16.5) and CVL (n = 5, median age 2.4 years, range 2.0-12.2) between January 2007 and December 2010.

Results: Primary access failure rate (patient-months) was 1 per 78.8 for AVF (n = 5) and 1 per 15.5 for CVLs (n = 7, p = 0.3). Failure thereafter was 1 per 131.3 and 1 per 18.5 for AVF and CVLs respectively (n = 3 and 6 respectively; p = 0.2). The annualised hospitalisation rate for access malfunction was 0.44% and 3.1% for AVFs and CVLs respectively (p = 0.004). Patients with AVFs had a lower infection rate of 0.25 per 100 patient-months compared with CVL at 3.2 per 100 (p = 0.002). There was no difference in dialysis adequacy or laboratory values between AVF and CVL groups. Access survival rates (including both primary and secondary access failure) were significantly higher for AVF compared with CVL (p = 0.0002, hazard ratio = 0.15, 95% confidence interval 0.04-0.37).

Conclusions: Patients with AVF spend less time in hospital than those dialysed by CVLs and have a much lower access infection rate. These findings emphasise the need to use AVF as first-line access for paediatric patients on chronic HD.
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http://dx.doi.org/10.1007/s00467-012-2318-2DOI Listing
February 2013

Outcome of surgical complications following simultaneous pancreas-kidney transplantation.

Nephrol Dial Transplant 2012 Apr 7;27(4):1658-63. Epub 2011 Sep 7.

Department of Transplantation, Guys and St Thomas’ NHS Foundation Trust, London, UK.

Background: Simultaneous pancreas-kidney (SPK) transplantation carries a higher risk of surgical complications than kidney transplantation alone. We aimed to establish the incidence of surgical complications after SPK transplantation and determine the effect on graft and patient survival.

Methods: Outcomes of all SPK transplants performed at our centre were compared between patients who experienced a surgical complication (SC group) and those who did not (NSC group).

Results: Our centre performed 193 SPK transplants in a 15-year period; 44 patients (23%) experienced a surgical complication. One-year and 5-year pancreatic graft survival was 89 and 80%, respectively; this was lower in the SC group. There was no significant difference in patient or kidney graft survival between the SC and NSC groups at 5 years (92 and 83%, respectively.)

Conclusion: Surgical complications following SPK transplantation can cause significant morbidity and adversely affect pancreas graft survival, but do not affect long-term kidney or patient survival.
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http://dx.doi.org/10.1093/ndt/gfr502DOI Listing
April 2012

How safe is hand-assisted laparoscopic donor nephrectomy?--results of 200 live donor nephrectomies by two different techniques.

Nephrol Dial Transplant 2009 Jan 18;24(1):293-7. Epub 2008 Aug 18.

Department of Transplant Surgery, Renal Unit, Guy's Hospital, Guy's and St Thomas' NHS Trust, London, UK.

Background: Despite the rapid introduction of laparoscopic living donor nephrectomy, doubts exist about safety compared with open surgery. Early series have often reported on selective donor groups. We present a consecutive, prospective analysis of morbidity following hand-assisted laparoscopic donor nephrectomy (HALDN) compared with historical controls undergoing open donation (ODN) in a total of 200 living donors at a single UK centre.

Methods: The results of 144 consecutively performed HALDN donors were compared to 56 preceding ODN patients. Patients with multiple arteries, right-sided nephrectomies and obesity were included. Data on recovery and complications were collected prospectively and consecutively.

Results: There were two (1.4%) major complications in the HALDN group and one in the ODN group (1.8%, P = 0.629). Additionally, there were 24 minor complications in 23 HADLN patients (16.7%), compared with 21 in 21 ODN patients (37.5%, P = 0.003). Time taken to return to normal activity and mean post-operative stay was significantly shorter for the HALDN group. There was no mortality in either group.

Conclusions: Contrary to concerns, we report a safe experience with HALDN with a low rate of major complications. Furthermore, our patients spend less time in hospital with an earlier return to normal activity compared with open donation.
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http://dx.doi.org/10.1093/ndt/gfn463DOI Listing
January 2009

Living-unrelated donor renal transplantation: an alternative to living-related donor transplantation?

Ann R Coll Surg Engl 2008 Apr;90(3):247-50

Department of Transplantation, Guy's and St Thomas' Hospitals & GKT School of Medicine, London, UK.

Introduction: An increasing number of living-unrelated, kidney donor transplants are being performed in our unit. We present a comparison of living-unrelated (LURD) and living-related donor (LRD) renal transplant outcomes and analyse influencing factors.

Patients And Methods: We retrospectively analysed the outcome of all living-donor renal transplants performed at our centre from 1993 to 2004. The parameters studied included patient and graft survival, functioning status of grafts (determined by estimated GFR) at last follow-up and any rejection episodes. Multivariate analysis was performed for recipient and donor age, ethnicity, HLA matching and re-transplants.

Results: A total of 322 live donor kidney transplants (LRD, n = 261; LURD, n = 61) were carried out over this period. Mean recipient age was 28 +/- 16 years in the LRD group and 48 +/- 12 years in LURD, while mean age of the donors was 43 +/- 11 years and 48 +/- 10 years, respectively. Caucasians constituted 80% of all the living donors. Amongst LRD, parents were the commonest (58%) donors followed by siblings (35%). In LURD, 80% were spouses. A total of 33 grafts failed, 30 in LRD (11%) and 3 in LURD (5%). Thirteen patients died, 11 (4.2%) in LRD (7 with functioning graft) and 2 (3.3%) in LURD (1 with functioning graft). Acute rejections occurred in 41% recipients in LRD and 35% in LURD (P = 0.37). Estimated GFR was lower in LURD than in LRD (49 +/- 14 versus 59 +/- 29 ml/min/1.73 m(2); P = 0.032). One- and 3-year patient survival for LRD and LURD was 98.7% and 96.3% and 97.7% and 95%, respectively (P = 0.75). One- and 3-year graft survival was equivalent at 94.8% and 92.3% for LRD, and 98.4% and 93.7% for LURD, respectively (P = 0.18).

Conclusions: Outcome of LRD and LURD is comparable in terms of patient and graft survival, acute rejection rate and estimated GFR despite differences in demographics, HLA matching and re-transplants of recipients.
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http://dx.doi.org/10.1308/003588408X261636DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430448PMC
April 2008

The axillary artery-popliteal vein extended polytetrafluoroethylene graft: a new technique for the complicated dialysis access patient.

Nephrol Dial Transplant 2004 Apr;19(4):998-1000

Department of Renal Surgery and Transplantation, St George's Hospital, Blackshaw Road, London SW17 0QT, UK.

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http://dx.doi.org/10.1093/ndt/gfg600DOI Listing
April 2004

Panning for gold: screening for potential live kidney donors.

Nephrol Dial Transplant 2004 May 19;19(5):1276-80. Epub 2004 Feb 19.

Department of Renal Medicine and Transplantation, St George's Hospital, Blackshaw Road, London SW17 0QT, UK.

Background: Living donation is one method of addressing the gulf between supply and demand for kidney transplants. However, few manage to complete the extensive work up procedure. This study reviews the reasons for failure to complete the live donor renal assessment and suggests options, which may improve the situation.

Methods: Retrospective analysis of data collected over 5 years between 1997 and 2001 of all potential live donors entering the assessment programme.

Results: 189 (103 female, 86 male) potential donors entered the assessment process. Thirty-four (18%) actually donated comprising 17 (50%) siblings, nine (26%) parents and eight (24%) unrelated donors. Of the 155 who did not donate, 46 (30%) had blood group or immunological incompatibility and 42 (27%) withdrew. Twenty-three (15%) were medically unfit, mostly due to cardiovascular disease and 16 (10%) had insufficient renal function for safe donation.

Conclusion: Live donor transplantation offers an attractive source of high quality organs, but considerable time and effort is required to realize this. Manipulation of immunological incompatibility, psychological assessment and counselling of those likely to withdraw may significantly enhance the yield. Support should also be provided for those unable to donate for whatever reason.
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http://dx.doi.org/10.1093/ndt/gfh045DOI Listing
May 2004