Vassilios Papalois

Imperial College London, Londinium, England, United Kingdom

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Publications (96)205.33 Total impact

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    ABSTRACT: Viability assessment during preservation is imperative to avoid unnecessary discard of marginal organs maximizing graft outcomes in kidney transplantation. To address this need, we have developed a novel system based on a rapid sampling microdialysis (rsMD) analyzer allowing continuous tissue monitoring and measurement of metabolic markers of cell damage. Our aim was to develop a tool that allows for accurate assessment of tissue metabolism and organ viability in the preservation period. Twenty-two porcine kidneys subjected to 15 min of warm ischemia underwent either 24 h of static cold storage (SCS) or 10 h of hypothermic machine perfusion (HMP). After preservation, tissue temperature was allowed to passively increase to ambient temperature as an ischemic challenge. Cortical and medullary metabolism was monitored throughout with online measurements of lactate concentrations made every 60 s. On commencement of monitoring, lactate concentrations were successfully detected within 15 mins. During the initial 1.5 h, lactate concentrations were similar during SCS (65 μM) and HMP (124 μM, P > 0.05) but lower after 10 h of SCS (SCS: 68 μM versus HMP: 230 μM, P < 0.001). Warming data suggest a resilience of HMP kidneys to subsequent temperature induced ischemia compared to SCS kidneys. This preliminary study provides the baseline ischemic profile for porcine kidneys while validating the technique of rsMD as a tool for organ viability assessment during preservation. The data characterize metabolic differences between SCS and HMP preserved allografts and can help elucidate why HMP is clinically superior to SCS allowing development of interventions to augment these benefits. Copyright © 2015 Elsevier Inc. All rights reserved.
    No preview · Article · Jul 2015 · Journal of Surgical Research
  • Hakim N · Papalois V · Epstein M

    No preview · Book · Feb 2015
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    ABSTRACT: 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.
    Full-text · Article · May 2014 · BMC Nephrology
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    ABSTRACT: In this study, we analyze the outcomes of transplant renal artery stenosis (TRAS), determine the different anatomical positions of TRAS, and establish cardiovascular and immunological risk factors associated with its development. One hundred thirty-seven of 999 (13.7%) patients had TRAS diagnosed by angiography; 119/137 (86.9%) were treated with angioplasty, of which 113/137 (82.5%) were stented. Allograft survival in the TRAS+ intervention, TRAS+ nonintervention and TRAS- groups was 80.4%, 71.3% and 83.1%, respectively. There was no difference in allograft survival between the TRAS+ intervention and TRAS- groups, p = 0.12; there was a difference in allograft survival between the TRAS- and TRAS+ nonintervention groups, p < 0.001, and between the TRAS+ intervention and TRAS+ nonintervention groups, p = 0.037. TRAS developed at the anastomosis, within a bend/kink or distally. Anastomotic TRAS developed in living donor recipients; postanastomotic TRAS (TRAS-P) developed in diabetic and older patients who received grafts from deceased, older donors. Compared with the TRAS- group, patients with TRAS-P were more likely to have had rejection with arteritis, odds ratio (OR): 4.83 (1.47-15.87), p = 0.0095, and capillaritis, OR: 3.03 (1.10-8.36), p = 0.033. Patients with TRAS-P were more likely to have developed de novo class II DSA compared with TRAS- patients hazard ratio: 4.41 (2.0-9.73), p < 0.001. TRAS is a heterogeneous condition with TRAS-P having both alloimmune and traditional cardiovascular risk factors.
    Full-text · Article · Jan 2014 · American Journal of Transplantation
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    Full-text · Article · Dec 2012 · International Journal of Surgery
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    ABSTRACT: Objectives: To satisfy donor organ shortage, overweight and obese donors are becoming a greater proportion of the kidney donor pool. Although good safety data exist in overweight and moderately obese individuals (body mass index = 25 to 35 kg/m²), there is little information about outcomes in morbidly obese donors (body mass index ≥ 40 kg/m²). The purpose of this study was to review the experience with morbidly obese donors in a single center and assist in the discussion about the feasibility of nephrectomy in such cases. Materials and methods: Outcomes of nephrectomy in morbidly obese donors between January 2005 and June 2010 were reviewed retrospectively and compared with outcomes in nonobese donors. Results: Of 386 nephrectomies, 7 involved morbidly obese donors. Mortality and major complication rates were low in all body mass index categories. A high incidence of minor postoperative complications was observed in the morbidly obese, with 57% morbidly obese patients requiring treatment for complications including respiratory infection, compared with 30% in nonobese donors (P < .05). There were no significant differences in mean operative time, estimated blood loss, and length of hospital stay between all body mass index categories. Limited follow-up data (mean, 20 mo) showed similar renal function parameters between groups. Conclusions: The limited data suggest that nephrectomy may be feasible in selected morbidly obese donors. Further study is needed before major conclusions can be made.
    No preview · Article · Dec 2012
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    ABSTRACT: Increasing demand for donor kidneys, in parallel with trends toward more elderly and obese populations, make it important to continuously review donor pool inclusion criteria. Acceptance of elderly and obese living donors remains controversial, with a higher incidence of comorbidity and the greater risk of postoperative complications sighted as reasons for caution. Drawing on our center's experience, we aim to determine whether older age and obesity are in fact associated with greater perioperative risk, and longer term complications in donors undergoing nephrectomy. Three hundred eighty-three living donor nephrectomies conducted at one of the United Kingdom's largest transplant units over the last 5 years were stratified into groups according to age and body mass index. Perioperative endpoints and postdonation follow-up data collected at 6-to-12-monthly intervals were analyzed and compared. No significant differences in operative parameters, including operative time and estimated blood loss, were reported between groups. Rates of early postoperative complications were not significantly different, although subgroup analysis showed a higher incidence of respiratory complications at the extremes of obesity (body mass index ≥ 40 kg/m²). On follow-up, renal function parameters showed significant change postnephrectomy, but between-group variation was not significant. Mortality and major complication rates were comparably low in all groups of study. In our unit's experience, nephrectomy in selected donors who may otherwise have been precluded from participation on account of their age or weight, is feasible and associated with perioperative and longer term outcomes comparable with their younger nonobese counterparts. It provides a basis for informed consent of "extended criteria" donors.
    No preview · Article · Apr 2012 · Transplantation
  • Danai Balfoussia · Dharani Yerrakalva · Karim Hamaoui · Vassilios Papalois
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    ABSTRACT: Solid organ transplant constitutes the definitive treatment for end-stage organ failure. Better organ preservation methods have enabled use of marginal grafts, thereby expanding the donor pool to meet the growing demand for organs. Static cold storage as a preservation method has been superseded largely by machine perfusion in kidney transplant, with work regarding its use in other organ transplants ongoing. We hope that machine perfusion will allow better graft preservation, and pretransplant assessment, and optimization. The most extensive laboratory, preclinical, and clinical research into machine perfusion organ preservation has focused on kidneys. Successful outcomes in its use in renal transplant have sparked interest for its development and application to the liver, pancreas, heart, and lungs. This article reviews the current state of machine perfusion in abdominal and thoracic organ transplant, focusing on the recent developments in assessing graft viability.
    No preview · Article · Apr 2012
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    I Laurence · B Ariff · R A Quest · S Moser · A Glover · D Taube · P Gishen · V Papalois · C Juli
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    ABSTRACT: Accurate pre-operative evaluation of renal vascular anatomy is essential for successful renal harvest in live donor transplantation. Non-contrast renal MR angiographic (MRA) techniques are potentially well suited to the screening of donors; however, their restricted imaging field of view (FOV) has previously been an important limitation. We sought to assess whether the addition of a large FOV balanced fast field echo (BFFE) steady-state free precession (SSFP) sequence to non-contrast SSFP MRA could overcome this problem. Comparison with contrast-enhanced MRA (CE MRA) and findings at surgery were performed. 22 potential renal donors each underwent SSFP and CE MRA. 11 out of 22 potential donors subsequently underwent a donor nephrectomy. All images were diagnostic. Both SSFP MRA and CE MRA identified an equal number of arteries. Surgery confirmed two accessory renal arteries, both demonstrated with both imaging techniques. A third accessory vessel was identified with both techniques on a kidney contralateral to the donated organ. 6 out of 11 procured kidneys demonstrated early branch arteries at surgery, 5 out of 6 of which had been depicted on both SSFP and CE MRA. The median grading of image quality for main renal arteries was slightly better for CE MRA (p=0.048), but for accessory vessels it was better for SSFP MRA. This pilot study indicates that by combining free-breathing SSFP MRA with large-FOV bFFE images, an accurate depiction of renal vascular anatomy without the need for intravenous contrast administration can be obtained, as compared with surgical findings and CE MRA.
    Preview · Article · Jan 2012 · The British journal of radiology
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    ABSTRACT: There are many views regarding the initiation of the process for live donor kidney transplantation (LDKT), the motives of the donor and the appropriate ways to promote LDKT. Health care professionals and patients were recruited in a tertiary renal and transplant centre and completed an anonymous questionnaire. They were then divided into focus groups and a structured interview was performed in order to discover the rationale behind the answers in the questionnaire. Four hundred and sixty-four participants completed the questionnaire. There were 168 health care professionals and 296 patients. Most of the participants (26.9%) suggested that the first approach to a potential donor should be made by the potential recipient. Participants believed that the most important motives for a kidney donor are relief as a result of the recipient's improved health after the transplant (82.5%) and altruism (80.4%). About 89.2% of participants believed that proper long-term medical follow-up of the donor is the most important factor for LDKT promotion. Fifty-five participants discussed the rationale of their answers in the focus group interview. In our study, participants preferred an initial approach of the donor by the recipient. The relief as a result of the recipient's improved health was suggested as a very strong motive for donation. Proper donor follow-up was considered to be paramount for the further development of LDKT.
    Full-text · Article · Dec 2011 · Nephrology Dialysis Transplantation

  • No preview · Article · Nov 2011 · BMJ (online)
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    ABSTRACT: ABOi transplantation is an accepted method of expanding the kidney donor pool but there is little analysis of the protocols used. We established an ABOi programme utilising leukocyte depletion, tacrolimus, TPE and IvIg. There are few reports in the literature on the success rates of antibody removal protocols or relating to patients in whom antibody removal fails. The purpose of this study was to define the likelihood of achieving transplantation depending on ABO antibody titers. 56 patients entered our ABOi program. Data were analysed to determine the likelihood of achieving transplantation, ABO antibody titre prior to antibody removal and amount of TPE required to achieve transplantation. The median antibody titer was 1:64 (Range 0-1:1024). Transplantation proceeded when the ABO titer reached ≤1:4. 51/56 (91%) patients achieved transplantation after 8.3±5 TPE. Five patients with high ABO titers were not transplanted despite extensive TPE. The number of TPE required to reach an ABO titer of ≤1:4 correlates best with pre-treatment IgG titers. This is the first study to demonstrate a cut off titer for entry in to the ABO incompatible program using the relationship between ABO titer and amount of TPE required to reach transplantation. We now tailor the antibody removal protocol prior to transplantation and have introduced a cut-off entry titer to the program (≤1:256), because of the unacceptable risk of exposing patients with higher titers to long-lasting immunosuppression and costly, prolonged, courses of TPE without the guarantee of successful transplantation. Patients whose ABO titer exceeds the cut-off are counselled and offered alternative routes to transplantation.
    No preview · Article · Sep 2011 · Transplantation
  • Paul T R Thiruchelvam · Vassilios E Papalois
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    ABSTRACT: The increasing shortage of donor kidneys available for transplantation combined with an ageing population has resulted in the use of expanded-criteria donor (ECD) kidneys. These kidneys are associated with an increased risk of delayed graft function, acute rejection and reduced graft survival. This paper will cover the use of ECDs and the presentation of risk to patients receiving these organs.
    No preview · Article · Sep 2011 · Clinical Ethics
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    ABSTRACT: Immunosuppressive regimens for kidney transplantation which reduce the long-term burden of immunosuppression are attractive, but little data are available to judge the safety and efficacy of the different strategies used. We tested the hypothesis that the simple, cheap, regimen of alemtuzumab induction combined with tacrolimus monotherapy maintenance provided equivalent outcomes to the more commonly used combination of interleukin-2 receptor monoclonal antibody induction with tacrolimus and mycophenolate mofetil combination maintenance, both regimens using steroid withdrawal after 7 days. One hundred twenty-three live or deceased donor renal transplant recipients were randomized 2:1 to receive alemtuzumab/tacrolimus or daclizumab/tacrolimus/mycophenolate. The primary endpoint was survival with a functioning graft at 1 year. Both regimens produced equivalent, excellent outcomes with the primary outcome measure of 97.6% in the alemtuzumab arm and 95.1% in the daclizumab arm at 1 year (95% confidence interval of difference 6.9% to -1.7%) and at 2 years 92.6% and 95.1%. Rejection was less frequent in the alemtuzumab arm with 1- and 2-year rejection-free survival of 91.2% and 89.9% compared with 82.3% and 82.3% in the daclizumab arm. There were no significant differences in terms of the occurrence of opportunistic infections. Alemtuzumab induction with tacrolimus maintenance monotherapy and short-course steroid use provides a simple, safe, and effective immunosuppressive regimen for renal transplantation.
    No preview · Article · Aug 2011 · Transplantation
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    ABSTRACT: Transplantation provides the best outcomes and quality of life for people with end-stage renal disease and therefore offers the optimum treatment of choice. Preemptive living donor (LD) transplantation is an increasingly preferable alternative to dialysis as transplantation outcomes indicate lower morbidity and mortality rates and greater graft and patient survival rates compared to those who are transplanted after dialysis has commenced. Despite nursing and medical teams giving information to patients regarding transplantation and living donation, the number of people coming forward for preemptive transplant work-up remained limited. Changing the format, environment, and quality of information given to patients and families seemed necessary in order to increase the number of preemptive transplants. Our data show that we have improved the access to the information seminars with attendance rising from 5 to 15 attendees per seminar (3 per year) in 2005 to average 65 attendees per seminar (6 per year) in 2010. By expanding the access to information for patients, their families and friends, living donation has increased with a growth in the proportion of preemptive LD transplants from 28% (23/81) in 2006 to 44% in 2010 (29/66; p = 0.05). We can conclude that expanding the pool accessing information has increased the number of preemptive (LD) transplants in our center.
    No preview · Article · Aug 2011 · Renal Failure
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    ABSTRACT: Swelling in an arteriovenous fistula (AVF) is commonly caused by thrombosis, aneurysm and infection. However, due to the increased risk of malignancy after transplantation, this should also be considered. We discuss 4 patients with malignancy confined to an AVF after renal transplantation presenting in a 2-year period. Angiosarcoma was diagnosed in 3 patients and the other had post-transplant lymphoproliferative disorder (PTLD). Angiosarcoma behaves aggressively and 2 of our patients died within 6 months of diagnosis. There are 6 previous cases and 5 died within 16 months of diagnosis. PTLD at AVFs has not been documented previously. Malignancy at an AVF is a rare but important differential that can impact significantly on patient morbidity and mortality. Predilection for malignancy at an AVF is not understood. We review the literature and discuss possible aetiologies.
    No preview · Article · Jun 2011 · American Journal of Nephrology
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    ABSTRACT: Acceptance of elderly or marginal health individuals as kidney donors is debated, with practices varying between centres. Transplant recipients, live kidney donors and health-care professionals caring for patients with renal failure were surveyed regarding their views on live donor kidney transplantation (LDKT) of marginal health (diabetes, hypertension, atherosclerosis, obesity, etc.) and elderly donors. Participants were recruited within a tertiary renal and transplant centre and invited to participate in focus groups and structured interviews. They also completed an anonymous questionnaire. Of 464 participants who completed the questionnaire (36% health-care professionals and 64% patients), 49% and 64%, respectively, stated that marginal and elderly donors should be accepted for LDKT. In the structured interviews, emphasis was given to presenting to donor, recipient and their respective families a calculated risk regarding the effect that either a nephrectomy or transplant has on long-term quality of life. Participants stated that an independent third party in addition to the transplant team should discuss involved risks. Issues of ‘how desperate’ the recipient's situation is should also be considered. Health-care professionals stated that regardless of the strength of will of an individual to donate a kidney (despite age, health problems or personal risk), they should always have the right to say ‘no’ if performing a specific LDKT was against their professional and ethical values. About half of those surveyed considered that marginal health and elderly donors were acceptable for LDKT. Emphasis was given to the explanation to donors and recipients of the risks involved in such transplantation.
    No preview · Article · Jun 2011 · Clinical Ethics
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    ABSTRACT: We surveyed the following groups of individuals concerning their attitudes towards the pathway leading up to live donor kidney transplantation (LDKT) and post-operative follow-up: kidney transplant (deceased and live donor) recipients, live kidney donors and medical and nursing staff caring for end-stage renal disease and dialysis patients. Participants were recruited within a tertiary renal and transplant centre and invited to complete anonymized questionnaires, be involved in focus groups and undertake structured interviews. A total of 464 participants completed the questionnaire (36% health care professionals and 64% patients). Most perceived donor risk as small or very small (62%), and 49% stated that a potential donor should be given up to 3 months to reconsider the decision to donate. Participants were almost equally divided as to whether consensus of the donor's family is necessary (46%) or not (44%) in LDKT. Seventy-one percentage of the participants suggested that patients have a greater appreciation of a LDKT if they have been on dialysis; 58% of participants thought that donor and recipient should recuperate beside each other after surgery; 45% thought that the post-operative follow-up for the donor should last up to a year; and 83% thought that donor follow-up should include medical status and quality of life. In the interviews, participants expressed several interesting views. Participants believed that LDKT is safe for the donor, and the pathway to surgery and post-operative follow-up should be performed in a way that ensures lack of coercion and includes family support and an extensive post-operative follow-up.
    No preview · Article · May 2011 · International Urology and Nephrology
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    ABSTRACT: Development of live donor kidney transplantation (LDKT) programs has intensified debate regarding acceptability of certain donor categories and potential commercialization. Concerning these issues, we surveyed the views of medical and nursing staff caring for patients with renal failure and renal transplant recipients and donors. Participants were recruited from a tertiary transplant unit and invited to complete an anonymous questionnaire. Four hundred and sixty-four participants completed the questionnaire (42% response). One hundred and sixty-eight (36.2%) were health care professionals and 296 (63.8%) patients; 85.6% of participants were willing to donate to their children, 80.2% to siblings, 80.8% to parents, 72% to a non-blood-related relative or friend, and 15.3% to a stranger. If participants had hypothetical renal failure, they were prepared to accept a kidney from a parent (79.5%), sibling (78.7%), child (56.3%), a non-blood-related relative or friend (79.3%), or stranger (54.1%). Regarding commercialization, responders' attitudes were that the donor should not accept financial reward (29.1%), be compensated for expenses only (60.6%), or should receive a direct financial reward (10.1%). For non-directed donation, 23.5%, 55.6%, and 20.7% were not in support of reward, compensation only, and financial reward, respectively. While live kidney donation was accepted by the majority of individuals surveyed, only the minority approved of commercialization.
    No preview · Article · Mar 2011 · Clinical Transplantation
  • E. Mazaris · P. Tekkis · V. Papalois
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    ABSTRACT: Introduction Surgical practice of the highest standards has always been based on sound knowledge of applied anatomy, sharp clinical judgment and excellent operative skills. In modern times, surgical practice is also integrated with basic and translational research in which the surgeon has to be actively and creatively involved.Tight monitoring of the outcomes of surgical practice and the development of evidence-based surgery is a central theme in modern surgery. Clinical audit is an important process for the continuous evaluation of care provided to patients, leading to the acknowledgement of drawbacks, and has become a driving force for future improvement. Thus, it is necessary for surgeons to familiarize themselves, as early as possible during their careers, with the basic principles. Acquiring informed consent is a crucial part of the daily practice of a surgeon. In modern healthcare, the patients rightly have a very strong say regarding their care and medical-legal problems arise more frequently. Therefore, surgeons have to be trained properly regarding the width and depth of the information they need to provide to the patients and their families prior to surgery regarding the type of operation, the potential problems and alternative treatments and allow them sufficient time and space to ‘digest the information’, ask questions and finally consent without coercion.
    No preview · Article · Jan 2011

Publication Stats

1k Citations
205.33 Total Impact Points


  • 2008-2015
    • Imperial College London
      Londinium, England, United Kingdom
  • 2006-2014
    • Ealing, Hammersmith & West London College
      Londinium, England, United Kingdom
  • 1998-2012
    • Imperial College Healthcare NHS Trust
      Londinium, England, United Kingdom
  • 2004
    • The Queen Elizabeth Hospital
      Tarndarnya, South Australia, Australia
  • 2002-2003
    • WWF United Kingdom
      Londinium, England, United Kingdom