Normothermic and hypothermic machine perfusion preservation versus static cold storage for deceased donor kidney transplantation.

BACKGROUND: Kidney transplantation is the optimal treatment for kidney failure. Donation, transport and transplant of kidney grafts leads to significant ischaemia reperfusion injury. Static cold storage (SCS), whereby the kidney is stored on ice after removal from the donor until the time of implantation, represents the simplest preservation method. However, technology is now available to perfuse or "pump" the kidney during the transport phase ("continuous") or at the recipient centre ("end-ischaemic"). This can be done at a variety of temperatures and using different perfusates. The effectiveness of these treatments manifests as improved kidney function post-transplant. OBJECTIVES: To compare machine perfusion (MP) technologies (hypothermic machine perfusion (HMP) and (sub) normothermic machine perfusion (NMP)) with each other and with standard SCS. SEARCH METHODS: We contacted the information specialist and searched the Cochrane Kidney and Transplant Register of Studies until 15 June 2024 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov. SELECTION CRITERIA: All randomised controlled trials (RCTs) and quasi-RCTs comparing machine perfusion techniques with each other or versus SCS for deceased donor kidney transplantation were eligible for inclusion. All donor types were included (donor after circulatory death (DCD) and brainstem death (DBD), standard and extended/expanded criteria donors). Both paired and unpaired studies were eligible for inclusion. DATA COLLECTION AND ANALYSIS: The results of the literature search were screened, and a standard data extraction form was used to collect data. Both of these steps were performed by two independent authors. Dichotomous outcome results were expressed as risk ratios (RR) with 95% confidence intervals (CI). Survival analyses (time-to-event) were performed with the generic inverse variance meta-analysis of hazard ratios (HR). Continuous scales of measurement were expressed as a mean difference (MD). Random effects models were used for data analysis. The primary outcome was the incidence of delayed graft function (DGF). Secondary outcomes included graft survival, incidence of primary non-function (PNF), DGF duration, economic implications, graft function, patient survival and incidence of acute rejection. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. MAIN RESULTS: Twenty-two studies (4007 participants) were included. The risk of bias was generally low across all studies and bias domains. The majority of the evidence compared non-oxygenated HMP with standard SCS (19 studies). The use of non-oxygenated HMP reduces the rate of DGF compared to SCS (16 studies, 3078 participants: RR 0.78, 95% CI 0.69 to 0.88; P < 0.0001; I2 = 31%; high certainty evidence). Subgroup analysis revealed that continuous (from donor hospital to implanting centre) HMP reduces DGF (high certainty evidence). In contrast, this benefit over SCS was not seen when non-oxygenated HMP was not performed continuously (low certainty evidence). Non-oxygenated HMP reduces DGF in both DCD and DBD settings in studies performed in the 'modern era' and when cold ischaemia times (CIT) were short. The number of perfusions required to prevent one episode of DGF was 7.69 and 12.5 in DCD and DBD grafts, respectively. Continuous non-oxygenated HMP versus SCS also improves one-year graft survival (3 studies, 1056 participants: HR 0.46, 0.29 to 0.75; P = 0.002; I2 = 0%; high certainty evidence). Assessing graft survival at maximal follow-up confirmed a benefit of continuous non-oxygenated HMP over SCS (4 studies, 1124 participants (follow-up 1 to 10 years): HR 0.55, 95% CI 0.40 to 0.77; P = 0.0005; I2 = 0%; high certainty evidence). This effect was not seen in studies where HMP was not continuous. The effect of non-oxygenated HMP on our other outcomes (PNF, incidence of acute rejection, patient survival, hospital stay, long-term graft function, duration of DGF) remains uncertain. Studies performing economic analyses suggest that HMP is either cost-saving (USA and European settings) or cost-effective (Brazil). One study investigated continuous oxygenated HMP versus non-oxygenated HMP (low risk of bias in all domains); the simple addition of oxygen during continuous HMP leads to additional benefits over non-oxygenated HMP in DCD donors (> 50 years), including further improvements in graft survival, improved one-year kidney function, and reduced acute rejection. One large, high-quality study investigated end-ischaemic oxygenated HMP versus SCS and found end-ischaemic oxygenated HMP (median machine perfusion time 4.6 hours) demonstrated no benefit compared to SCS. The impact of longer periods of end-ischaemic HMP is unknown. One study investigated NMP versus SCS (low risk of bias in all domains). One hour of end ischaemic NMP did not improve DGF compared with SCS alone. An indirect comparison revealed that continuous non-oxygenated HMP (the most studied intervention) was associated with improved graft survival compared with end-ischaemic NMP (indirect HR 0.31, 95% CI 0.11 to 0.92; P = 0.03). No studies investigated normothermic regional perfusion (NRP) or included any donors undergoing NRP. AUTHORS' CONCLUSIONS: Continuous non-oxygenated HMP is superior to SCS in deceased donor kidney transplantation, reducing DGF, improving graft survival and proving cost-effective. This is true for both DBD and DCD kidneys, both short and long CITs, and remains true in the modern era (studies performed after 2008). In DCD donors (> 50 years), the simple addition of oxygen to continuous HMP further improves graft survival, kidney function and acute rejection rate compared to non-oxygenated HMP. Timing of HMP is important, and benefits have not been demonstrated with short periods (median 4.6 hours) of end-ischaemic HMP. End-ischaemic NMP (one hour) does not confer meaningful benefits over SCS alone and is inferior to continuous HMP in an indirect comparison of graft survival. Further studies assessing NMP for viability assessment and therapeutic delivery are warranted and in progress.

Posterior urethral valves and kidney transplantation: Identifying opportunities for improvement.

BACKGROUND: Posterior urethral valves (PUV) represents a heterogenous spectrum in which guidelines for management are lacking particularly for those patients facing end-stage kidney disease and transplant. In this study we aim to 1) evaluate our long term PUV pediatric transplant outcomes compared to those without lower urinary tract dysfunction and 2) assess our PUV cohort for trends in bladder management and evaluate outcomes to inform development of institutional guidelines. MATERIALS AND METHODS: A retrospective cohort analysis of all patients with a diagnosis of PUV who underwent kidney transplant from 2000 to 2023 was completed. A matched cohort of patients without lower urinary tract dysfunction was identified for comparison of graft function. Charts of PUV patients were reviewed for both sociodemographic and clinical variables. Patients were classified by bladder management at the time of transplantation into three separate groups for analysis: voiding, clean intermittent catheterization, and incontinent diversion. Primary outcomes of interest were eGFR, graft failure, and UTIs post-transplant. RESULTS: 45 patients met inclusion criteria. 69% were on dialysis prior to transplant. 51% of grafts were from a deceased donor. Bladder management consisted of voiding (62%), CIC (4 via urethra, 10 via channel) (31%), and incontinent diversion (7%). 20% underwent augmentation cystoplasty (5 = ureter, 2 = gastric, 1 = colon, and 1 = ileum) prior to or at the time of transplant. Median follow up duration was 5.4 years (3.0, 10.8). Patients on CIC had higher rates of UTI; however, we found no significant difference in graft function outcomes (eGFR, graft failure) between bladder management groups or year of transplant. VUR in the transplant kidney was associated with vesicostomy (p = 0.028). 2 of 2 gastric augments developed malignancy, one of which was cause of death. Graft failure rate was 22% in both the PUV group and matched cohort, with median interval times to failure of 6.7 years and 3.7 years, respectively (p = 0.71). There were no differences in eGFR at follow-up time points between the PUV and matched cohort. CONCLUSIONS: Patients with PUV represent a spectrum of disease with heterogeneous management before and after kidney transplant. Overall, graft function outcomes were similar when compared to matched cohort without lower urinary tract dysfunction. Patients on CIC had higher rates of UTI but without impact on graft function. Gastric augmentation cystoplasty should be avoided given risk for malignancy. Guidelines to standardize evaluation and management would be helpful for patient care and outcomes.

White-light activatable organic NIR-II luminescence nanomaterials for imaging-guided surgery.

While second near-infrared (NIR-II) fluorescence imaging is a promising tool for real-time surveillance of surgical operations, the previously reported organic NIR-II luminescent materials for in vivo imaging are predominantly activated by expensive lasers or X-ray with high power and poor illumination homogeneity, which significantly limits their clinical applications. Here we report a white-light activatable NIR-II organic imaging agent by taking advantages of the strong intramolecular/intermolecular D-A interactions of conjugated Y6CT molecules in nanoparticles (Y6CT-NPs), with the brightness of as high as 13315.1, which is over two times that of the brightest laser-activated NIR-II organic contrast agents reported thus far. Upon white-light activation, Y6CT-NPs can achieve not only in vivo imaging of hepatic ischemia reperfusion, but also real-time monitoring of kidney transplantation surgery. During the surgery, identification of the renal vasculature, post-reconstruction assessment of renal allograft vascular integrity, and blood supply analysis of the ureter can be vividly depicted by using Y6CT-NPs with high signal-to-noise ratios upon clinical laparoscopic LED white-light activation. Our work provides efficient molecular design guidelines towards white-light activatable imaging agent and highlights an opportunity for precision imaging theranostics.

The impact of preservation solutions for static cold storage on kidney transplantation outcomes: Results of a Brazilian nationwide multicenter study.

This study evaluated the current practices of selecting cold storage preservation solutions in Brazil and their impact on delayed graft function (DGF) incidence and 1-year outcomes in kidney transplant recipients. A retrospective cohort study was conducted, including 3,134 brain-dead deceased donor kidney transplants performed between 2014 and 2015 in 18 Brazilian centers. The most commonly used preservation solution was Euro-collins (EC, 55.4%), followed by Histidine-tryptophan-ketoglutarate (HTK, 30%) and Institut Georges Lopez (IGL-1, 14.6%). The incidence of DGF was 54.4%, with 11.7% of patients requiring dialysis for more than 14 days, indicating prolonged DGF. Upon adjusting for confounding variables, HTK demonstrated a significantly lower risk of DGF than EC (OR 0.7350.82500.926), as did IGL-1 (OR 0.6050.7120.837). Similar protective effects were observed for prolonged DGF when comparing HTK (OR 0.4780.5990.749) and IGL-1 (OR 0.4780.6810.749) against EC. No significant association was found between preservation solutions and 1-year death-censored graft survival. In conclusion, EC was the most frequently used cold storage perfusion solution, demonstrating a higher incidence and duration of DGF compared with HTK and IGL-1, but with no impact on 1-year graft survival.

Optimizing Quality of Life in Kidney Transplant Recipients Through Structured Exercise: A Systematic Review and Evidence-Based Guidelines.

With the progress of medicine and the maturity of surgery, the improvement of quality of life (QOL) in kidney transplant patients has gradually attracted widespread attention. There is evidence that exercise training has a beneficial effect on patients with renal transplantation. To discover whether exercise can improve patient QOL, this study collected the existing evidence about the effect of structured exercise training on the QOL of renal transplant recipients. Under the guidance of the 5 steps of evidence-based practice, relevant literature in various resources, from 2000 to 2023, was searched. Using the method of systematic review, a PRISMA table was made, and the studies were screened by inclusion and exclusion criteria. Then, the reports were reviewed and the data were extracted. Finally, 5 qualified randomized controlled trials for exercise training of renal transplant recipients were identified. All 5 studies evaluated the health outcomes of patients' QOL. Through the method of evidence-based practice, it was proven that exercise intervention can improve patient QOL after renal transplantation and accelerate their early postoperative recovery. This study integrates and discusses the evidence related to exercise training and QOL of renal transplant recipients to gain an in-depth understanding of the improvements of exercise on patients' QOL and the shortcomings of current clinical implementation. It provides evidence for medical staff to provide exercise interventions to help these transplant patients recover their health and return to daily life.

Successful Kidney Transplantation Using Elderly Living Donor with Extremely Large Renal Cyst and Double Arteries.

The authors describe a kidney transplant procedure using a living donor with a large cyst and double arteries. Due to the lack of regular transplant activity from a deceased donors, we decided to use the, so called, expanded criteria living donors, which means older age (more than 65 years), hypertension, some structural anomalies of the kidneys (cysts, multiple renal arteries), ABO incompatible kidney transplant, etc. The surgical procedure was the unroofing of a large cyst and wadding with perirenal fat. The 10 years survival rate is quite successful and we can recommend it.

Robotic versus open mini-incision living donor nephrectomy: Single centre experience.

BACKGROUND: Robotic surgery is associated with less tissue manipulation and earlier recovery with minimal incision. The aim of this study was to compare the short-term clinical outcomes between robotic-assisted donor nephrectomy (RDN) and open mini-incision donor nephrectomy (ODN). METHODS: From 2016 to 2019, 141 cases involving RDN were analysed. Patient outcomes were compared with those of 191 patients who underwent ODN from 2010 to 2015. Demographics, operation factors, perioperative outcomes, and complications were retrospectively reviewed. RESULTS: The RDN group presented with less blood loss than the ODN group (p = 0.023). The length of hospital stay was significantly shorter in the RDN group than in the ODN group (p < 0.005). The overall rate of complications was low and there was no significant difference in complication rates between the groups. CONCLUSION: The robotic approach has benefits over the traditional open approach, including shorter length of hospital stay and reduced intraoperative blood loss.

Efficacy of lengthening right renal veins using accompanying gonadal veins in living donor kidney transplantation.

BACKGROUND: Short harvested right renal veins (RV) are quite common in living donor kidney transplantation (KT). This technical difficulty might interfere implanting and increase warm ischemic time. Several techniques to overcome this problem have been applied, including iliac vein transposition, inverted transplant, synthetic graft, saphenous vein… Application of accompanying gonadal vein (GV), which is easily approachable and less time-consuming, has been recently published. This study aims to evaluate its effectiveness and safety. METHODS: Retrospective study on KT using the gonadal vein to lengthen the short right renal vein at Viet Duc University Hospital from April 2019 to April 2022. The following data were gathered: baseline characteristics, vascular imaging in CT scan/after nephrectomy and after reconstruction (mm), reconstruction and surgical time, hospitalization days. The outcomes were determined by kidney function after transplantation (plasma creatinine, creatinine clearance) and related complications. RESULTS: Twenty-five cases with procured right kidney with short RV from the living donor which were reconstructed and lengthened by the accompanying GV were collected. The additional length of RV was 15.9 ± 2.4 mm. Average cold ischemic time, venoplasty time, warm ischemic time were 60.4 ± 8.2, 21.2 ± 5.3, and 38.1 ± 5.6 min, respectively. The average hospital stay was 15.3 ± 3.2 days. Average follow-up time was 31 ± 5.2 months, creatinine clearance was around 60 ml/min after 1 year, no vascular or urologic complications was observed. CONCLUSION: Accompanying GV from a living donor to lengthen short right RV in KT is a feasible, safe, and effective technique.

Anterior quadratus lumborum block provided superior pain control and reduced opioid consumption in kidney transplantation: A randomized controlled trial.

BACKGROUND: The research aimed to assess the effectiveness of inside-out anterior quadratus lumborum (QL3) block and local wound infiltration in managing postoperative pain and total morphine dosage following kidney transplantation. METHODS: In this prospective, randomized, double-blind study; 46 end-stage renal disease patients undergoing kidney transplantation were randomly allocated into 2 groups: a QL group (n = 23) receiving 20 mL of 0.25% bupivacaine using the ultrasound-assisted inside-out technique before wound closure, while the local wound infiltration (LA) group (n = 23) receiving the same dose around the surgical wound and drain at the time of skin closure. The primary outcome measure was the numerical pain rating scale, with secondary outcomes including amount of morphine consumption at various postoperative time points (2nd, 4th, 6th, 12th, 18th and 24th hours). RESULTS: Patients in the QL group had significantly lower numerical rating scale scores at the 2nd and 4th hours, both at rest and during movement (P < .05). Although pain scores at rest and during movement at later time points were lower in the QL group compared to the LA group, these differences were not statistically significant. Cumulative morphine consumption at postoperative 4th, 6th, 12th, 18th and 24th hours was significantly lower in the QL group (P < .05). No patients experienced complications from the QL3 block. CONCLUSION: Ultrasound-assisted inside-out QL3 block significantly reduced postoperative pain levels at the 2nd and 4th hours, both at rest and during movement, and led to a reduction in cumulative morphine consumption from the 4th hour postoperatively, and persisting throughout the 24-hour period.

Urologists' proficiency in various donor nephrectomy approaches: a real-life survey, systematic review, and meta-analysis of randomized controlled trials.

INTRODUCTION: Donor nephrectomy (DN) is a unique surgical procedure in urological practice, as it involves exposing a healthy individual to the potential risks of surgery. This type of surgery exhibits heterogeneity in terms of approach (open, laparoscopic, or robotic), each with its unique set of advantages and disadvantages. Consequently, there is currently a lack of universally agreed upon clear guidelines. In these settings, this study aims to evaluate transplantation surgeons' knowledge through a real-life survey and compare it with data from published randomized controlled trials (RCTs). EVIDENCE ACQUISITION: The study is divided into two parts, with the first part focusing on the outcomes of the real-life survey designed to assess surgeons' knowledge about different DN approaches and their real-world practices during the surgery. The second part involves a systematic review and meta-analysis of RCTs, specifically examining the outcomes of different surgical approaches to DN. The systematic review followed the PRISMA Guidelines and involved a search of PubMed and Web of Science for RCTs comparing the outcomes of different DN approaches. The risk of bias was assessed using the RoB-2 tool. The random effect model was mainly used to assess the mean difference of the included studies. EVIDENCE SYNTHESIS: The study was conducted between July 2021 and January 2022 and surveyed 50 surgeons, of which 35 participants (70%) completed the survey. Regarding various approaches to DN, 97.14% of surgeons reported having experience with live DN, and 45.72% performed over 15 cases per year. The most performed approach was pure laparoscopic DN (68.57%). Pure laparoscopic DN was the preferred approach for 77.42% of respondents. The review process resulted in 335 articles, of which 35 were eligible for inclusion in the systematic review. In summary, most studies found that laparoscopic approaches, including standard, hand-assisted, LESS-DN, and mini-LDN, resulted in less postoperative pain, better cosmetic, and quicker recovery times compared to open approaches. The main limitation of the current study is the heterogeneity of the included studies. CONCLUSIONS: The study provides valuable insights into the practices of renal transplantation surgeons, offering a comprehensive comparison to level 1 studies (RCTs) in the field. It underscores the continued significance of ODN in contemporary practice, particularly in light of recommendations from the EAU guidelines on renal transplantation. This reaffirms the need to consider the advantages and disadvantages of various approaches, including factors such as cost, postoperative pain, and cosmetic outcomes. While robotic-assisted DN holds promise, their adoption remains variable, potentially due to limited robust evidence.

Timing Considerations for Sleeve Gastrectomy in Kidney Transplant Patients: A Single Center Evaluation.

Current scientific literature is deficient in detailing the optimal timing for conducting bariatric surgery in relation to kidney transplantation. In this study, we performed a retrospective evaluation of kidney transplant recipients with BMI >35 kg/m2. It aimed to provide data on those who received both sleeve gastrectomy (SG) and kidney transplantation (KT) simultaneously, as well as on patients who underwent SG and KT at different times, either before or after. In addition, the acceptance levels of the bariatric surgery among different scenarios were assessed. Our findings demonstrated that combined KT and SG led to successful weight loss, in contrast to undergoing kidney transplant alone, while maintaining comparable rates of graft and patient survival. Weight loss was similar between recipients who had a combined operation and those who underwent SG following the transplant. Additionally, over a median time frame of 1.7 years, patients who underwent SG before KT exhibited a statistically significant reduction in BMI at the time of the transplant. Notably, our study highlights that patients offered the combined procedure were significantly more likely to undergo SG compared to those for whom SG was presented at a different operative time than the transplant.

Safety and graft outcome of right retroperitoneal laparoscopic donor nephrectomy for living donor kidney transplantation: A comparison with left retroperitoneal laparoscopic donor nephrectomy.

INTRODUCTION: The left kidney is often preferred for living donor kidney transplantation because of its anatomical advantages. However, the right kidney may be procured due to donor conditions. Few studies have assessed the safety and graft outcome of right retroperitoneal laparoscopic donor nephrectomy (RDN). This study aimed to compare the outcomes between right and left RDN with respect to donor outcome and the graft function of recipients. METHODS: This retrospective study included 230 consecutive living donor kidney transplants performed at our institution between May 2019 and March 2023. We reviewed the outcomes of kidney transplant in the right and left kidneys after RDN. RESULTS: A total of 230 living donor kidney transplants were performed, with 32 donors receiving right RDN (right RDN group) and 198 donors receiving left RDN (left RDN group). The renal veins and ureters were significantly shorter in the right RDN group than in the left RDN group (both p < .001). Donor operation and warm ischemia time were significantly longer in the right RDN group than in the left RDN group (p = .012 and p < .001, respectively). None of the groups exhibited any cases of delayed graft function owing to donor-related reasons. Perioperative changes in the estimated glomerular filtration rate of recipients and death-censored graft survival were not significantly different between the two groups. CONCLUSIONS: In RDN, the outcomes of right donor nephrectomy were comparable to those of left donor nephrectomy in terms of donor safety and recipient renal function.

Intensive Surveillance of Porcine-Rhesus Kidney Xenotransplant Using Different Ultrasound Techniques.

BACKGROUND: Significant progress has been made in kidney xenotransplantation in the past few years, and this field is accelerating towards clinical translation. Therefore, surveillance of the xenograft with appropriate tools is of great importance. Ultrasonography has been widely used in kidney allotransplantation and served as an economical and non-invasive method to monitor the allograft. However, questions remain whether the ultrasonographic criteria established for human kidney allograft could also be applied in xenotransplantation. METHODS: In the current study, we established a porcine-rhesus life sustaining kidney xenotransplantation model. The xenograft underwent intensive surveillance using gray-scale, colorful Doppler ultrasound as well as 2D shear wave elastography. The kidney growth, blood perfusion, and cortical stiffness were measured twice a day. These parameters were compared with the clinical data including urine output, chemistry, and pathological findings. RESULTS: The observation continued for 16 days after transplantation. Decline of urine output and elevated serum creatinine were observed on POD9 and biopsy proven antibody-mediated rejection was seen on the same day. The xenograft underwent substantial growth, with the long axis length increased by 32% and the volume increased by threefold at the end of observation. The resistive index of the xenograft arteries elevated in response to rejection, together with impaired cortical perfusion, while the peak systolic velocity (PSV) was not compromised. The cortical stiffness also increased along with rejection. CONCLUSION: In summary, the ultrasound findings of kidney xenograft shared similarities with those in allograft but possessed some unique features. A modified criteria needs to be established for further application of ultrasound in kidney xenotransplantation.

Robotic performance metrics model fellow proficiency in living donor nephrectomy.

We investigated the use of robotic objective performance metrics (OPM) to predict number of cases to proficiency and independence among abdominal transplant fellows performing robot-assisted donor nephrectomy (RDN). 101 RDNs were performed by 5 transplant fellows from September 2020 to October 2023. OPM included fellow percent active control time (%ACT) and handoff counts (HC). Proficiency was defined as ACT ≥ 80% and HC ≤ 2, and independence as ACT ≥ 99% and HC ≤ 1. Case number was significantly associated with increasing fellow %ACT, with proficiency estimated at 14 cases and independence at 32 cases (R2 = 0.56, p < 0.001). Similarly, case number was significantly associated with decreasing HC, with proficiency at 18 cases and independence at 33 cases (R2 = 0.29, p < 0.001). Case number was not associated with total active console time (p = 0.91). Patient demographics, operative characteristics, and outcomes were not associated with OPM, except for donor estimated blood loss (EBL), which positively correlated with HC. Abdominal transplant fellows demonstrated proficiency at 14-18 cases and independence at 32-33 cases. Total active console time remained unchanged, suggesting that increasing fellow autonomy does not impede operative efficiency. These findings may serve as a benchmark for training abdominal transplant surgery fellows independently and safely in RDN.

Access to robotic assisted kidney transplant for recipients: a systematic review and call for reporting standards.

Robot-assisted kidney transplantation (RAKT) is a relatively novel, minimally invasive option for kidney transplantation. However, clarity on recipient selection in the published literature is lacking thereby significantly limiting interpretation of safety and other outcomes. This systematic review aimed to identify and synthesize the data on selection of RAKT recipients, compare the synthesized data to kidney transplant recipients across the USA, and explore geographical clusters of availability of RAKT. Systematic literature review, in accordance with PRISMA, via OVID MEDLINE, Embase, and Web of science from inception to March 5, 2023. All data entry double blinded and quality via Newcastle Ottawa Scale. 44 full-text articles included, encompassing approximately 2402 kidney transplant recipients at baseline but with considerable suspicion for overlap across publications. There were significant omissions of information across studies on patient selection for RAKT and/or analysis. Overall, the quality of studies was very low. Given suspicion of overlap across studies, it is difficult to determine how many RAKT recipients received living (LD) versus deceased donor (DD) organs, but a rough estimate suggests 89% received LD. While the current RAKT literature provides preliminary evidence on safety, there are significant omissions in reporting on patient selection for RAKT which limits interpretation of findings. Two recommendations: (1) international consensus is needed for reporting guidelines when publishing RAKT data and (2) larger controlled trials consistently reporting recipient characteristics are needed to clearly determine selection, safety, and outcomes across both LD and DD recipients.

Comparison of preemptive and non-preemptive kidney transplantation outcomes in children aged <6 years.

We aimed to compare the outcomes of pediatric kidney transplantation (KT) between preemptive KT (PEKT) and non-PEKT in children aged < 6 years. Seventy-four pediatric recipients aged < 6 years who underwent KT were divided into the PEKT and non-PEKT groups. They were retrospectively evaluated for patient and graft survival, graft function, growth, and cytomegalovirus (CMV) infection. Comparison of the groups (PEKT, n = 14; non-PEKT, n = 60) revealed no significant differences between them in terms of distribution of sex, age, weight, primary disease, or population of pre-transplant CMV immunoglobulin G-positive patients. The median estimated glomerular filtration rate before KT in the PEKT and non-PEKT groups was 11.4 and 7.3 (mL/min/1.73 m2) (P < .001), respectively, and the median duration of dialysis was 2.7 years in the non-PEKT group. Graft survival at 5 years was 100% and 95% in the PEKT and non-PEKT groups, respectively (P = .634). One patient in the non-PEKT group had vascular complications, with subsequent early graft loss. Incidence of CMV infection was significantly lower in the PEKT group (P = .044). There were no significant differences in post-transplant estimated glomerular filtration rate, acute rejection, or growth. The height standard deviation score showed catch-up growth after KT in both groups. There was no significant difference in transplant outcomes in recipients aged < 6 years, with or without pre-transplant dialysis, except for the incidence of CMV infection. Therefore, PEKT in younger children should be performed aggressively by experienced multi-disciplinary teams.