What are the benefits of preemptive versus non-preemptive kidney transplantation? A systematic review and meta-analysis.

Opting for a preemptive kidney transplant (PKT) can help avoid costs and morbidity associated with dialysis. However, while multiple studies have shown clinical benefits of PKT, other studies have not demonstrated this, leading to controversy in the literature regarding the exact benefits of PKT. Therefore, this study aimed to determine the clinical outcomes of PKT versus non-preemptive kidney transplantation (nPKT) in adult patients. Multiple databases were searched up to May 4, 2022. Independent reviewers selected studies for inclusion and extracted relevant data. Risk of bias was assessed using the Downs and Black checklist. Eighty-seven studies including 859,715 adult kidney transplant patients were included the review. The risk of patient death (relative risk [95% confidence interval] 0.74 [0.60-0.91]) was significantly lower in PKT versus nPKT patients for living donor (LD) transplants, whereas the risk of overall graft loss was significantly lower in PKT compared to nPKT patients for both LD (0.72 [0.62-0.83]) as well as deceased donor (DD) transplants (0.80 [0.69-0.92]). The evidence suggests that LD PKT patients have a lower risk of patient death and graft loss compared to nPKT patients, and DD PKT patients have a lower risk of graft loss than nPKT patients.

Is Preemptive Kidney Transplantation Associated With Improved Outcomes when Compared to Non-preemptive Kidney Transplantation in Children? A Systematic Review and Meta-Analysis.

Main Problem: Preemptive kidney transplantation (PKT) is performed prior to dialysis initiation to avoid dialysis-related morbidity and mortality in children and adolescents. We undertook a systematic review to compare clinical outcomes in PKT versus kidney transplantation after dialysis initiation in paediatric patients. Methods: The bibliographic search identified studies that compared paediatric recipients of a first or subsequent, living or deceased donor PKT versus non-preemptive kidney transplant. Methodological quality was assessed for all studies. Data were pooled using the random-effects model. Results: Twenty-two studies (n = 22,622) were included. PKT reduced the risk of overall graft loss (relative risk (RR) .57, 95% CI: .49-.66) and acute rejection (RR: .81, 95% CI: .75-.88) compared to transplantation after dialysis. Although no significant difference was observed in overall patient mortality, the risk of patient death was found to be significantly lower in PKT patients with living donor transplants (RR: .53, 95% CI: .34-.83). No significant difference was observed in the incidence of delayed graft function. Conclusion: Evidence from observational studies suggests that PKT is associated with a reduction in the risk of acute rejection and graft loss. Efforts should be made to promote and improve rates of PKT in this group of patients (PROSPERO). Systematic Review Registration: https://clinicaltrials.gov/, CRD42014010565.

The Impact of Cold Ischaemia Time on Outcomes of Living Donor Kidney Transplantation: A Systematic Review and Meta-Analysis.

Studies have been carried out to investigate the effect of a prolonged cold ischaemia time (CIT) on the outcomes of living donor kidney transplantation (LDKT). There is no clear consensus in the literature about the effects of CIT on LDKT outcomes, and therefore, we performed a systematic review and meta-analysis to provide evidence on this subject. Searches were performed in five databases up to 12 July 2021. Articles comparing different CIT in LDKT describing delayed graft function (DGF), graft and patient survival, and acute rejection were considered for inclusion. This study is registered with PROSPERO, CRD42019131438. In total, 1452 articles were found, of which eight were finally eligible, including a total of 164,179 patients. Meta-analyses showed significantly lower incidence of DGF (odds ratio (OR) = 0.61, p < 0.01), and significantly higher 1-year graft survival (OR = 0.72, p < 0.001) and 5-year graft survival (OR = 0.88, p = 0.04), for CIT of less than 4 h. Our results underline the need to keep CIT as short as possible in LDKT (ideally < 4 h), as a shorter CIT in LDKT is associated with a statistically significant lower incidence of DGF and higher graft survival compared to a prolonged CIT. However, clinical impact seems limited, and therefore, in LDKT programmes in which the CIT might be prolonged, such as kidney exchange programmes, the benefits outweigh the risks. To minimize these risks, it is worth considering including CIT in kidney allocation algorithms and in general take precautions to protect high risk donor/recipient combinations.

Timing of Ureteric Stent Removal and Occurrence of Urological Complications after Kidney Transplantation: A Systematic Review and Meta-Analysis.

Implanting a ureteric stent during ureteroneocystostomy reduces the risk of leakage and ureteral stenosis after kidney transplantation (KTx), but it may also predispose to urinary tract infections (UTIs). The aim of this study is to determine the optimal timing for ureteric stent removal after KTx. Searches were performed in EMBASE, MEDLINE Ovid, Cochrane CENTRAL, Web of Science, and Google Scholar (until November 2017). For this systematic review, all aspects of the Cochrane Handbook for Interventional Systematic Reviews were followed and it was written based on the PRISMA-statement. Articles discussing JJ-stents (double-J stents) and their time of removal in relation to outcomes, UTIs, urinary leakage, ureteral stenosis or reintervention were included. One-thousand-and-forty-three articles were identified, of which fourteen articles (three randomised controlled trials, nine retrospective cohort studies, and two prospective cohort studies) were included (describing in total n = 3612 patients). Meta-analysis using random effect models showed a significant reduction of UTIs when stents were removed earlier than three weeks (OR 0.49, CI 95%, 0.33 to 0.75, p = 0.0009). Regarding incidence of urinary leakage, there was no significant difference between early (<3 weeks) and late stent removal (>3 weeks) (OR 0.60, CI 95%, 0.29 to 1.23, p = 0.16). Based on our results, earlier stent removal (<3 weeks) was associated with a decreased incidence of UTIs and did not show a higher incidence of urinary leakage compared to later removal (>3 weeks). We recommend that the routine removal of ureteric stents implanted during KTx should be performed around three weeks post-operatively.

Attitudes among transplant professionals regarding shifting paradigms in eligibility criteria for live kidney donation.

BACKGROUND: The transplant community increasingly accepts extended criteria live kidney donors, however, great (geographical) differences are present in policies regarding the acceptance of these donors, and guidelines do not offer clarity. The aim of this survey was to reveal these differences and to get an insight in both centre policies as well as personal beliefs of transplant professionals. METHODS: An online survey was sent to 1128 ESOT-members. Questions were included about several extended donor criteria; overweight/obesity, older age, vascular multiplicity, minors as donors and comorbidities; hypertension, impaired fasting glucose, kidney stones, malignancies and renal cysts. Comparisons were made between transplant centres of three regions in Europe and between Europe and other countries worldwide. RESULTS: 331 questionnaires were completed by professionals from 55 countries. Significant differences exist between regions in Europe in acceptance of donors with several extended criteria. Median refusal rate for potential live donors is 15%. Furthermore, differences are seen regarding pre-operative work-up, both in specialists who perform screening as in preoperative imaging. CONCLUSIONS: Remarkably, 23.4% of transplant professionals sometimes deviate from their centre policy, resulting in more or less comparable personal beliefs regarding extended criteria. Variety is seen, proving the need for a standardized approach in selection, preferably evidence based.

Vascular Multiplicity Should Not Be a Contra-Indication for Live Kidney Donation and Transplantation.

BACKGROUND: Whether vascular multiplicity should be considered as contraindication and therefore 'extended donor criterion' is still under debate. METHODS: Data from all live kidney donors from 2006-2013 (n = 951) was retrospectively reviewed. Vascular anatomy as imaged by MRA, CTA or other modalities was compared with intraoperative findings. Furthermore, the influence of vascular multiplicity on outcome of donors and recipients was studied. RESULTS: In 237 out of 951 donors (25%), vascular multiplicity was present. CTA had the highest accuracy levels regarding vascular anatomy assessment. Regarding outcome of donors with vascular multiplicity, warm ischemia time (WIT) and skin-to-skin time were significantly longer if arterial multiplicity (AM) was present (5.1 vs. 4.0 mins and 202 vs. 178 mins). Skin-to-skin time was significantly longer, and complication rates were higher in donors with venous multiplicity (203 vs. 180 mins and 17.2% vs. 8.4%). Outcome of renal transplant recipients showed a significantly increased WIT (30 vs. 26.7 minutes), higher rate of DGF (13.9% vs. 6.9%) and lower rate of BPAR (6.9% vs. 13.9%) in patients receiving a kidney with AM compared to kidneys with singular anatomy. CONCLUSIONS: We conclude that vascular multiplicity should not be a contra-indication, since it has little impact on clinical outcome in the donor as well as in renal transplant recipients.

Erratum: Body mass index and outcome in renal transplant recipients: a systematic review and meta-analysis.

This is an Erratum to BMC Medicine 2015, 13:111 indicating the correct name for one of the authors.Please see related article: http://www.biomedcentral.com/1741-7015/13/111. Authors' corrected note: Jan NM IJzermans last name was incorrectly spelled in the author list and was indicated as Jan NM IJermans in our published article [1]. The erratum includes this author's correct last name. The erratum includes this information. Corrected text: Jan NM IJzermans

Body mass index and outcome in renal transplant recipients: a systematic review and meta-analysis.

BACKGROUND: Whether overweight or obese end stage renal disease (ESRD) patients are suitable for renal transplantation (RT) is often debated. The objective of this review and meta-analysis was to systematically investigate the outcome of low versus high BMI recipients after RT. METHODS: Comprehensive searches were conducted in MEDLINE OvidSP, Web of Science, Google Scholar, Embase, and CENTRAL (the Cochrane Library 2014, issue 8). We reviewed four major guidelines that are available regarding (potential) RT recipients. The methodology was in accordance with the Cochrane Handbook for Systematic Reviews of Interventions and written based on the PRISMA statement. The quality assessment of studies was performed by using the GRADE tool. A meta-analysis was performed using Review Manager 5.3. Random-effects models were used. RESULTS: After identifying 5,526 studies addressing this topic, 56 studies were included. We extracted data for 37 outcome measures (including data of more than 209,000 RT recipients), of which 26 could be meta-analysed. The following outcome measures demonstrated significant differences in favour of low BMI (<30) recipients: mortality (RR = 1.52), delayed graft function (RR = 1.52), acute rejection (RR = 1.17), 1-, 2-, and 3-year graft survival (RR = 0.97, 0.95, and 0.97), 1-, 2-, and 3-year patient survival (RR = 0.99, 0.99, and 0.99), wound infection and dehiscence (RR = 3.13 and 4.85), NODAT (RR = 2.24), length of hospital stay (2.31 days), operation duration (0.77 hours), hypertension (RR = 1.35), and incisional hernia (RR = 2.72). However, patient survival expressed in hazard ratios was in significant favour of high BMI recipients. Differences in other outcome parameters were not significant. CONCLUSIONS: Several of the pooled outcome measurements show significant benefits for 'low' BMI (<30) recipients. Therefore, we postulate that ESRD patients with a BMI >30 preferably should lose weight prior to RT. If this cannot be achieved with common measures, in morbidly obese RT candidates, bariatric surgery could be considered.

Shifting paradigms in eligibility criteria for live kidney donation: a systematic review.

As the organ shortage increases, inherently the demand for donor kidneys continues to rise. Thus, live kidney donation is essential for increasing the donor pool. In order to create successful expansion, extended criteria live kidney donors should be considered. This review combines current guidelines with all available literature in this field, trying to seek and establish the optimal extended criteria. Comprehensive searches were carried out in major databases until November 2013 to search for articles regarding older age, overweight and obesity, hypertension, vascular anomalies/multiplicity, nulliparous women, and minors as donors. Of the 2079 articles found, 152 fell within the scope of the review. Five major guidelines were included and reviewed. Based on the literature search, live kidney donation in older donors (up to 70 years of age) seems to be safe as outcome is comparable to younger donors. Obese donors have comparable outcome to lean donors, in short- and mid-term follow-up. Since little literature is available proving the safety of donation of hypertensive donors, caution is advised. Vascular multiplicity poses no direct danger to the donor and women of childbearing age can be safely included as donors. Although outcome after donation in minors is shown to be comparable to adult donors, they should only be considered if no other options exist. We conclude that the analyzed factors above should not be considered as absolute contraindications for donation.

The need for a standardized informed consent procedure in live donor nephrectomy: a systematic review.

BACKGROUND: Informed consent in live donor nephrectomy is a topic of great interest. Safety and transparency are key items increasingly getting more attention from media and healthcare inspection. Because live donors are not patients, but healthy individuals undergoing elective interventions, they justly insist on optimal conditions and guaranteed safety. Although transplant professionals agree that consent should be voluntary, free of coercion, and fully informed, there is no consensus on which information should be provided, and how the donors' comprehension should be ascertained. METHODS: Comprehensive searches were conducted in Embase, Medline OvidSP, Web-of-Science, PubMed, CENTRAL (The Cochrane Library 2014, issue 1) and Google Scholar, evaluating the informed consent procedure for live kidney donation. The methodology was in accordance with the Cochrane Handbook for Interventional Systematic Reviews and written based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. RESULTS: The initial search yielded 1,009 hits from which 21 articles fell within the scope of this study. Procedures vary greatly between centers, and transplant professionals vary in the information they disclose. Although research has demonstrated that donors often make their decision based on moral reasoning rather than balancing risks and benefits, providing them with accurate, uniform information remains crucial because donors report feeling misinformed about or unprepared for donation. Although a standardized procedure may not provide the ultimate solution, it is vital to minimize differences in live donor education between transplant centers. CONCLUSION: There is a definite need for a guideline on how to provide information and obtain informed consent from live kidney donors to assist the transplant community in optimally preparing potential donors.

Ischemic postconditioning in human DCD kidney transplantation is feasible and appears safe.

Ischemic postconditioning may improve outcome after kidney transplantation. We performed a pilot study to assess feasibility and safety of ischemic postconditioning in human donation-after-circulatory-death kidney transplantation. Twenty patients were included. Primary outcome was rate of serious adverse events. Secondary outcomes were incidence of DGF and renal function at 3 months. Data were compared to a historical control group (n = 40). Furthermore, we performed a paired kidney analysis using the contralateral kidney (n = 11). Donor age and serum creatinine were higher in the experimental group compared with historical control: 57.7 (20-71) vs. 51.5 (24-74) years (P = 0.01) and 79 (40-156) µmol/l vs. 64 (25-115) µmol/l (P = 0.047). Postconditioning could be applied all times. One complication, a venous tear, occurred related to postconditioning. The experimental group experienced more DGF (85% vs. 63%) (P = 0.07). Serum creatinine at month 3 was 166 (109-331) µmol/l vs. 159 (81-279) µmol/l (P = 0.71). Paired kidney analysis showed no significant differences in DGF (72.2% vs. 54.5%, P = 0.66) and serum creatinine 199 (90-473) µmol/l vs. 184 (117-368) µmol/l (P = 0.76). This is the first report of applying IPoC in human kidney transplantation. Although IPoC is feasible and appears to be safe, no benefit in terms of reduced DGF or better renal function was observed (Dutch trial registry number NTR 3117).

A systematic review and meta-analysis of the influence of peritoneal dialysis catheter type on complication rate and catheter survival.

Peritoneal dialysis (PD) is an effective treatment for end-stage renal disease. There are several configurations of PD catheter design that may impact catheter function, such as the shape of the intraperitoneal segment, the number of cuffs, and the subcutaneous configuration. This review and meta-analysis was carried out to determine whether there is a clinical advantage for one of the catheter types or configurations. Comprehensive searches were conducted in MEDLINE, Embase, and CENTRAL (the Cochrane Library 2012, issue 10). The methodology was in accordance with the Cochrane Handbook for Interventional Systematic Reviews and written based on the PRISMA statement. The initial search yielded 682 hits from which 13 randomized controlled trials were identified. Outcomes of interest were as follows: catheter survival, drainage dysfunction, migration, leakage, exit-site infections, peritonitis, and catheter removal. Comparing straight vs. swan neck and single vs. double-cuffed catheters, no differences were found when results were pooled. Comparison of straight vs. coiled-tip catheters demonstrated that survival was significantly different in favor of straight catheters (hazard ratio 2.05; confidence interval 1.10-3.79, P=0.02). For surgically inserted catheters, the removal rate and survival at 1 year after insertion were significantly in favor of straight catheters. Our meta-analysis clearly demonstrates benefits for catheters with a straight intraperitoneal segment.

Laparoscopic versus open peritoneal dialysis catheter insertion: a meta-analysis.

BACKGROUND: Peritoneal dialysis is an effective treatment for end-stage renal disease. Key to successful peritoneal dialysis is a well-functioning catheter. The different insertion techniques may be of great importance. Mostly, the standard operative approach is the open technique; however, laparoscopic insertion is increasingly popular. Catheter malfunction is reported up to 35% for the open technique and up to 13% for the laparoscopic technique. However, evidence is lacking to definitely conclude that the laparoscopic approach is to be preferred. This review and meta-analysis was carried out to investigate if one of the techniques is superior to the other. METHODS: Comprehensive searches were conducted in MEDLINE, Embase and CENTRAL (the Cochrane Library 2012, issue 10). Reference lists were searched manually. The methodology was in accordance with the Cochrane Handbook for interventional systematic reviews, and written based on the PRISMA-statement. RESULTS: Three randomized controlled trials and eight cohort studies were identified. Nine postoperative outcome measures were meta-analyzed; of these, seven were not different between operation techniques. Based on the meta-analysis, the proportion of migrating catheters was lower (odds ratio (OR) 0.21, confidence interval (CI) 0.07 to 0.63; P = 0.006), and the one-year catheter survival was higher in the laparoscopic group (OR 3.93, CI 1.80 to 8.57; P = 0.0006). CONCLUSIONS: Based on these results there is some evidence in favour of the laparoscopic insertion technique for having a higher one-year catheter survival and less migration, which would be clinically relevant.

Systematic review and meta-analysis of the relation between body mass index and short-term donor outcome of laparoscopic donor nephrectomy.

In this era of organ donor shortage, live kidney donation has been proven to increase the donor pool; however, it is extremely important to make careful decisions in the selection of possible live donors. A body mass index (BMI) above 35 is generally considered as a relative contraindication for donation. To determine whether this is justified, a systematic review and meta-analysis were carried out to compare perioperative outcome of live donor nephrectomy between donors with high and low BMI. A comprehensive literature search was performed in MEDLINE, Embase, and CENTRAL (the Cochrane Library). All aspects of the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement were followed. Of 14 studies reviewed, eight perioperative donor outcome measures were meta-analyzed, and, of these, five were not different between BMI categories. Three found significant differences in favor of low BMI (29.9 and less) donors with significant mean differences in operation duration (16.9 min (confidence interval (CI) 9.1-24.8)), mean difference in rise in serum creatinine (0.05 mg/dl (CI 0.01-0.09)), and risk ratio for conversion (1.69 (CI 1.12-2.56)). Thus, a high body mass index (BMI) alone is no contraindication for live kidney donation regarding short-term outcome.