LightGBM outperforms other machine learning techniques in predicting graft failure after liver transplantation: Creation of a predictive model through large-scale analysis.

BACKGROUND: The incidence of graft failure following liver transplantation (LTx) is consistent. While traditional risk scores for LTx have limited accuracy, the potential of machine learning (ML) in this area remains uncertain, despite its promise in other transplant domains. This study aims to determine ML's predictive limitations in LTx by replicating methods used in previous heart transplant research. METHODS: This study utilized the UNOS STAR database, selecting 64,384 adult patients who underwent LTx between 2010 and 2020. Gradient boosting models (XGBoost and LightGBM) were used to predict 14, 30, and 90-day graft failure compared to conventional logistic regression model. Models were evaluated using both shuffled and rolling cross-validation (CV) methodologies. Model performance was assessed using the AUC across validation iterations. RESULTS: In a study comparing predictive models for 14-day, 30-day and 90-day graft survival, LightGBM consistently outperformed other models, achieving the highest AUC of.740,.722, and.700 in shuffled CV methods. However, in rolling CV the accuracy of the model declined across every ML algorithm. The analysis revealed influential factors for graft survival prediction across all models, including total bilirubin, medical condition, recipient age, and donor AST, among others. Several features like donor age and recipient diabetes history were important in two out of three models. CONCLUSIONS: LightGBM enhances short-term graft survival predictions post-LTx. However, due to changing medical practices and selection criteria, continuous model evaluation is essential. Future studies should focus on temporal variations, clinical implications, and ensure model transparency for broader medical utility.

IN.PACT AV access randomized trial: Japan cohort outcomes through 12 months.

PURPOSE: There is a lack of adjudicated and prospectively randomized published outcomes on the use of drug-coated balloons (DCB) to treat dysfunctional arteriovenous fistula in Asian patients. This post hoc subgroup analysis of 112 Japanese participants from the global IN.PACT AV Access trial reports outcomes through 12 months. MATERIALS AND METHODS: Participants were treated with DCB (n = 58) or standard non-coated percutaneous transluminal angioplasty (PTA) balloons (n = 54). Outcomes included target lesion primary patency (TLPP), access circuit primary patency, and safety. RESULTS: Through 6 months, TLPP was 86.0% (49/57) in the DCB group and 49.1% (26/53) in the PTA group (p < 0.001). Through 12 months, TLPP was 67.3% (37/55) in the DCB group and 43.4% (23/53) in the PTA group (p = 0.013). CONCLUSION: In this post hoc analysis of Japanese participants from the IN.PACT AV Access trial, participants treated with DCB had higher TLPP through 6 and 12 months compared with PTA.

The uric acid-urea distribution volume ratio is a potential marker of hydration status in patients on hemodialysis.

The distribution volume of uric acid is affected by the amount of extracellular water (ECW), while urea distribution volume can be considered as total body water (TBW). Thus, the ratio of distribution volumes of uric acid and urea can be paralleled to and be considered as the proxy of ECW/TBW. A total of 108 patients at our facility was included. The uric acid and urea distribution volume ratio (UUVdR) calculated from the single-pool model, which was measured within 1 month of the time when the bioimpedance index was measured. ECW/TBW at the end of the HD session was measured by InBody S10. We investigated the association between the UUVdR and the ECW/TBW values and the factors affecting the residuals of the regression equation. We also evaluated the predictive ability of overhydration or dehydration in randomly selected two groups, i.e., the training group and the validation group. ECW/TBW correlated highly with UUVdR. Multivariate analysis demonstrated that only creatinine and ECW/TBW were significantly associated with regression residuals. The cutoff values of UUVdR for overhydration and dehydration were 0.666 and 0.579, respectively, in the training group. Their AUC were 0.872 and 0.898, respectively. The sensitivity and specificity values in the validation group were 0.571 and 0.868 for overhydration, and 0.444 and 0.953 for dehydration, respectively. UUVdR might be a proxy of hydration status in hemodialysis patients. It may be possible to predict hydration status without dedicated devices in the epidemiological study.

Machine learning for morbid glomerular hypertrophy.

A practical research method integrating data-driven machine learning with conventional model-driven statistics is sought after in medicine. Although glomerular hypertrophy (or a large renal corpuscle) on renal biopsy has pathophysiological implications, it is often misdiagnosed as adaptive/compensatory hypertrophy. Using a generative machine learning method, we aimed to explore the factors associated with a maximal glomerular diameter of ≥ 242.3 µm. Using the frequency-of-usage variable ranking in generative models, we defined the machine learning scores with symbolic regression via genetic programming (SR via GP). We compared important variables selected by SR with those selected by a point-biserial correlation coefficient using multivariable logistic and linear regressions to validate discriminatory ability, goodness-of-fit, and collinearity. Body mass index, complement component C3, serum total protein, arteriolosclerosis, C-reactive protein, and the Oxford E1 score were ranked among the top 10 variables with high machine learning scores using SR via GP, while the estimated glomerular filtration rate was ranked 46 among the 60 variables. In multivariable analyses, the R2 value was higher (0.61 vs. 0.45), and the corrected Akaike Information Criterion value was lower (402.7 vs. 417.2) with variables selected with SR than those selected with point-biserial r. There were two variables with variance inflation factors higher than 5 in those using point-biserial r and none in SR. Data-driven machine learning models may be useful in identifying significant and insignificant correlated factors. Our method may be generalized to other medical research due to the procedural simplicity of using top-ranked variables selected by machine learning.

Correcting anemia and native vitamin D supplementation in kidney transplant recipients: a multicenter, 2 × 2 factorial, open-label, randomized clinical trial.

Anemia and vitamin D deficiency are associated with allograft failure, and hence, are potential therapeutic targets among kidney transplant recipients (KTRs). We conducted a multicenter, two-by-two factorial, open-label, randomized clinical trial to examine the effects of anemia correction and vitamin D supplementation on 2-year change in eGFR among KTRs (CANDLE-KIT). We enrolled 153 patients with anemia and >1-year history of transplantation across 23 facilities in Japan, and randomly assigned them to either a high or low hemoglobin target (>12.5 vs. <10.5 g/dl) and to either cholecalciferol 1000 IU/day or control. This trial was terminated early based on the planned interim intention-to-treat analyses (α = 0.034). Among 125 patients who completed the study, 2-year decline in eGFR was smaller in the high vs. low hemoglobin group (i.e., -1.6 ± 4.5 vs. -4.0 ± 6.9 ml/min/1.73 m2 ; P = 0.021), but did not differ between the cholecalciferol and control groups. These findings were supported by the fully adjusted mixed effects model evaluating the rate of eGFR decline among all 153 participants. There were no significant between-group differences in all-cause death or the renal composite outcome in either arm. In conclusion, aggressive anemia correction showed a potential to preserve allograft kidney function.

Impact of visceral fat area in patients with chronic kidney disease.

Longitudinal studies evaluating the association between visceral fat area (VFA) and kidney function decline in patients with chronic kidney disease (CKD) are limited, and little is known about VFA interactions contributing to the kidney prognosis (e.g. interactions between VFA ≥ 100 cm2 and age, sex, and CKD category). In this study, we stratified patients with CKD according to VFA category, as well as age, sex, CKD category, hyperglycemia, and diabetes mellitus, and determined the ability of obesity-related indicators (body mass index, waist circumference, subcutaneous fat area, visceral-to-subcutaneous fat ratio) to predict the renal prognosis. Kidney outcomes (≥ 50% estimated glomerular filtration rate decline or end-stage kidney disease) were examined in 200 patients with CKD (median follow-up, 12.3 years). On multivariable Cox analysis, an increase in VFA (10-cm2 increase) was significantly associated with kidney outcomes in the entire cohort, and VFA was significantly associated with kidney disease progression even in the VFA < 100 cm2 sub-cohort. Interestingly, the hazard ratio (HR) was higher for VFA (10-cm2 increase) than for the VFA ≥ 100 cm2 sub-cohort (HR 1.33 vs. 1.07). Overall, VFA was found to be the most versatile obesity-related indicator associated with kidney disease progression. VFA was associated with the primary outcome in the sub-cohorts of CKD stages 1-2, hyperglycemia, and diabetes mellitus. A high VFA was a significant kidney prognostic factor in the entire CKD cohort, with greater significance in patients with VFA < 100 cm2 than in patients with VFA ≥ 100 cm2. Our results may provide new insights into strategies for treating CKD.

Maximum Carotid Intima-Media Thickness in Association with Renal Outcomes.

AIM: We aimed to examine the association between the maximum intima-media thickness of the carotid artery (Max IMT) and renal prognosis, considering their potential interaction with age. METHODS: Survival analyses were performed in 112 patients with chronic kidney disease (CKD), to assess renal prognosis, with the endpoint defined as a ≥ 30% decline in estimated glomerular filtration rate (eGFR) or end-stage renal disease. RESULTS: During a median follow-up of 12.5 years, 44 participants reached the study endpoint. The major determinant of Max IMT was the maximum IMT of the internal carotid artery (Max ICA-IMT), which was the distribution ratio of 50.0% of Max IMT. Kaplan-Meier analyses showed that Max IMT ≥ 1.5 mm was significantly associated with renal prognosis when age and eGFR were matched. On multivariate Cox regression analysis, Max IMT was significantly associated with the renal outcomes and had a significant interaction with the age categories (≥ 65 years or ＜65 years) (P=0.0153 for interaction). A 1-mm increase in Max IMT was significantly associated with disease progression in the sub-cohort ＜65 years age-category, but not in the ≥ 65 years age-category; similarly the hazard ratio (HR) in the ＜65 years age-category was higher than in the ≥ 65 years age-category (HR: 2.52 vs. 0.95). Comparable results were obtained for Max ICA-IMT, Max bulb-IMT, but not for Max common carotid artery-IMT. CONCLUSIONS: A higher Max IMT was a significant renal prognosis factor in patients with CKD aged ＜65 years. Our results may provide new insights into treating CKD.

Sex Differences in Time-Series Changes in Pseudo-R2 Values Regarding Hyperuricemia in Relation to the Kidney Prognosis.

Studies on sex differences in time-series changes in pseudo-R2 values regarding hyperuricemia (HU) in relation to the kidney prognosis among patients with chronic kidney disease (CKD) are scant. The kidney prognosis was evaluated in 200 patients with CKD (median follow-up, 12.3 years). Survival analyses and logistic regression analyses were conducted, generating time-series pseudo-R2 values. We used four definitions of HU according to serum uric acid (SUA) levels (HU6, SUA ≥ 6.0 mg/dL; HU7, SUA ≥ 7.0 mg/dL; HU8, SUA ≥ 8.0 mg/dL) and antihyperuricemic agent use to calculate the mean and percentage of the change in pseudo-R2 values from the 6th year until the end of the study (6Y-End Mean and 6Y-End Change, respectively). The multivariable Cox regression analysis showed that HU7 was significantly associated with kidney outcomes. When stratified by sex, the 6Y-End Mean was clearly higher in women than in men for all HU definitions, with the highest value (0.1755) obtained for HU7 in women. The pseudo-R2 values for HU6 in women showed an increasing pattern, with a 6Y-End Change of 11.4%/year. Thus, it may be clinically meaningful to consider sex differences in the time-series pseudo-R2 values regarding HU and kidney outcomes.

Visceral to subcutaneous fat ratio as an indicator of a ≥30% eGFR decline in chronic kidney disease.

Whether the visceral-to-subcutaneous fat ratio (V/S ratio) is associated with renal prognosis in patients with chronic kidney disease (CKD) remains unclear. Furthermore, little is known about the effect of sex and the absolute amount of visceral fat accumulation such as visceral fat area (VFA) ≥100 cm2 on the V/S ratio in relation to renal prognosis. In this study, 200 patients with CKD were evaluated for renal prognosis. Survival analyses and logistic regression analyses were conducted, generating time-series pseudo-R2 values. The mean and percent change of the pseudo-R2 values from the 6th year to the 10th year (6Y-10Y Mean and 6Y-10Y Change, respectively) were calculated for determining the cut-off points for the medium-term renal prognosis. Multivariate Cox regression analysis revealed that the V/S ratio was significantly associated with renal outcomes and that the VFA category (VFA ≥ 100 cm2) had significant interactions with the V/S ratio regarding renal prognosis. The hazard ratio (HR) of the V/S ratio was higher in the sub-cohort of VFA < 100 cm2 than in the sub-cohort of VFA ≥ 100 cm2 (HR: 6.42 vs. 1.00). Regarding sex differences, a strong association was noted between the V/S ratio and renal prognosis in women but not in men (HR: 2.40 vs. 1.10). On the other hand, 6Y-10Y Mean of the pseudo-R2 values indicated differences in the cut-off points of the V/S ratio between men and women (V/S ratio: 0.75 vs. 0.5). Our findings indicate that it may be clinically meaningful to consider the differences in sex and the amount of VFA ≥100 cm2 for the V/S ratio in relation to renal outcomes in patients with CKD. The 6Y-10Y Mean of the pseudo-R2 values contributed to determining the cut-off points of the V/S ratio according to the sex difference.

Preoperative assessment system for hand-assisted laparoscopic donor nephrectomy by discriminant analysis.

We developed a preoperative assessment system to predict surgical workload in hand-assisted laparoscopic donor nephrectomy (HALDNx) using the normal-based linear discriminant rule (NLDR). A total of 128 cases of left HALDNx performed by a single operator were used as training data. Surgical workload was measured by operative time. The optimized model had 9 explanatory variables: age, total protein, total cholesterol, number of renal arteries (numberRA), 4 variables of perinephric fat (PNF), and thickness of subcutaneous fat. This model was validated using cross-validation and the .632 estimator to estimate discrimination rates with future test data. PNF and numberRA were the predominant factors affecting workload followed by the computed tomography value of PNF, body weight, and male sex. The estimated accuracy of the prediction system was 94.6%. The complication rate was 9.38% and did not correlate with surgical workload. We also made our program available online for constructing assessment functions from other cohort data. In conclusion, the surgical workload of HALDNx could be predicted with PNF and numberRA as the dominant risk factors.

Single fixed low-dose rituximab as induction therapy suppresses de novo donor-specific anti-HLA antibody production in ABO compatible living kidney transplant recipients.

This study was conducted to evaluate de novo donor-specific anti-human leukocyte antigen (HLA) antibody (dnDSA) production leading to antibody-mediated rejection (ABMR) after rituximab induction in non-sensitized ABO-compatible living kidney transplantation (ABO-CLKTx). During 2008-2015, 318 ABO-CLKTx were performed at the Department of Surgery III at Tokyo Women's Medical University Hospital. To reduce confounding factors, we adopted a propensity score analysis, which was applied with adjustment for age, gender, duration of pretransplant dialysis, HLA mismatch count, preformed DSA, non-insulin-dependent diabetes mellitus, immunosuppressive treatment, and estimated glomerular filtration rate (eGFR) on postoperative day 7. Using a propensity score matching model (1:1, 115 pairs), we analyzed the long-term outcomes of 230 ABO-CLKTx recipients retrospectively. Recipients were classified into a rituximab-treated (RTX-KTx, N = 115) group and a control group not treated with rituximab (C-KTx, N = 115). During five years, adverse events, survival rates for grafts and patients, and incidence of biopsy-proven acute rejection (BPAR) and dnDSA production for the two groups were monitored and compared. All recipients in the RTX-KTx group received rituximab induction on preoperative day 4 at a single fixed low dose of 100 mg; the CD19+ B cells were eliminated completely before surgery. Of those recipients, 13 (11.3%) developed BPAR; 1 (0.8%) experienced graft loss. By contrast, of C-KTx group recipients, 25 (21.7%) developed BPAR; 3 (2.6%) experienced graft loss. The RTX-KTx group exhibited a significantly lower incidence of BPAR (P = .041) and dnDSA production (13.9% in the RTX-KTx group vs. 26.9% in the C-RTx group, P = .005). Furthermore, lower incidence of CMV infection was detected in the RTX-KTx group than in the C-KTx group (13.9% in the RTX-KTx group vs. 27.0% in the C-KTx group, P = .014). No significant difference was found between groups for several other factors: renal function (P = .384), graft and patient survival (P = .458 and P = .119, respectively), and the respective incidences of BK virus infection (P = .722) and leukopenia (P = .207). During five-year follow-up, single fixed low-dose rituximab therapy is sufficient for ensuring safety, reducing rejection, and suppressing dnDSA production for immunological low-risk non-sensitized ABO-CLKTx.

Trough Level of Mycophenolic Acid Did Not Affect De Novo DSA Development in Kidney Transplantation.

INTRODUCTION: Mycophenolate mofetil has improved long-term outcomes of kidney transplantation. However, the impact of mycophenolic acid (MPA) trough level on the development of de novo donor-specific anti-HLA antibody (DSA) is unclear. We examined the relation between MPA trough level and de novo DSA development. METHOD: We retrospectively studied 617 kidney recipients whose MPA trough level and de novo DSA data were available. All patients underwent primary kidney transplant from living donors from 2008 to 2014, and were chronically treated with a calcineurin inhibitor, mycophenolate mofetil, and +/- steroids. They were equally divided into 4 groups according to the mean trough level of MPA (mMPA) at 1 year post-transplantation: Group 1, mMPA < 2.14 ng/mL (n = 152); Group 2, mMPA 2.14-2.83 ng/mL (n = 157); Group 3, mMPA 2.83-3.57 ng/mL (n = 153); and Group 4, mMPA ≥ 3.57 ng/mL (n = 155). The groups were compared by incidence rate of de novo DSA, graft survival rate, and renal function. RESULTS: The incidence rates of de novo DSA were 33.3% in Group 1, 23.7% in Group 2, 22.9% in Group 3, and 30.3% in Group 4 (P = .158). Although there was no significant difference in graft survival rates, a significant difference of renal functions was noted: the higher the renal function, the lower the MPA trough level. CONCLUSION: The mMPA trough level at 1 year post-transplantation was not statistically associated with the incidence rate of de novo DSA after kidney transplantation.

Primary Nonfunction on Kidney Transplant Recipients From Donation After Circulatory Death Donors.

BACKGROUND: The need for donor pool expansion remains an important task for kidney transplantation. The aim of this study is the evaluation of primary nonfunction (PNF) from donation after circulatory death (DCD) kidneys. METHODS: Between 1996 and 2017, 100 kidney transplants from DCD donors were conducted in our department. We retrospectively analyzed PNF of kidney transplant recipients from DCD donors in terms of donors' and recipients' epidemiologic characteristics. RESULTS: Of 100 grafts, 95 recipients (95.0%) had discontinued hemodialysis at the time of hospital discharge. Only 5 recipients (5.0%) developed PNF. All 5 PNF recipients received a single graft from an expanded criteria donor (ECD). The mean donor age in the PNF group was 65.0 (SD, 6.2) years. Significant differences between the PNF group and discontinued dialysis group were found for donor age (P < .01) and for the use of ECD kidneys (P < .02). Nevertheless, no significant difference was found between groups for several factors: a history of hypertension and cerebrovascular events, terminal creatinine levels, and graft weight. CONCLUSION: The incidence of PNF from DCD kidneys was very low. Although ECD kidneys in older donors might be a significant risk factor for PNF, these findings suggest that DCD kidneys should be used more frequently for donor expansion.

Single Graft Utilization From Donors With Severe Acute Kidney Injury After Circulatory Death.

Chronic shortages of organs for transplantation have led to the use of marginal kidneys from donors after circulatory death with acute kidney injury (AKI), but the utilization of kidneys with severe AKI is not well established. We retrospectively analyzed eight kidney transplantation (KTx) cases from donation after circulatory death (DCD) with terminal creatinine (t-Cr) concentrations higher than 10.0 mg/dL and/or oliguria for more than 5 days (AKI network criteria: stage III). Although all patients showed delayed graft function, no cases of primary nonfunction (PNF) were found. Five patients maintained stable renal function for approximately 15.5, 10, 10, 5, and 0.5 years after KTx. Only 1 patient showed biopsy-proven acute rejection. Also, 2 patients developed graft failure: one attributable to chronic antibody mediated rejection at 11.3 years after KTx, and one attributable to recurrence of IgA nephropathy at 4.6 years after KTx. Kidneys with AKI stage III yielded great outcomes without the risk of primary nonfunction and rejection. Although the AKI kidneys were associated with delayed graft function, these results suggest that even the most severe kidneys with AKI stage III from DCD donors can be considered a valid alternative for recipients on a waiting list for KTx.

Longterm renal allograft survival after sequential liver-kidney transplantation from a single living donor.

Combined liver-kidney transplantation (CLKT) is well established as a definitive therapy with the potential to provide complete recovery for certain liver-kidney diseases, although the results might be contingent on the cause of transplantation. The purposes of the present study were to review the longterm outcome of renal allografts in CLKT patients from single living donors and to investigate the beneficial factors, compared with solitary renal transplantation. Thirteen patients underwent sequential liver transplantation (LT) and kidney transplantation (KT) from single living donors. The indications for KT were oxaluria (n = 7), autosomal recessive polycystic disease (n = 3), and others (n = 3). The same immunosuppressive regimen used after LT was also used after KT. KT was performed between 1.7 and 47.0 months after the LT. The overall patient survival rate was 92.3% at 10 years. In 12 of the 13 surviving patients, the renal allografts were found to be functioning in 11 patients after a mean follow-up period of 103.6 months. The death-censored renal allograft survival rate at 10 years was 100%, which was better than that of KT alone (84.9%) in Japan. Immunological protection conferred by the preceding liver allograft may have contributed to the longterm outcomes of the renal allografts. In addition, the donation of double organs from a single living and related donor may have a favorable impact on the graft survival rate. In the future, investigations of factors affecting the longterm outcome of renal allografts, including details of the involvement of de novo donor-specific antibody, will be needed. Liver Transplantation 23 315-323 2017 AASLD.

Successful Long-term Graft Survival of a Renal Transplantation Patient with Wiskott-Aldrich Syndrome.

Wiskott-Aldrich syndrome, a rare X-linked hereditary syndrome, is characterized by immunodeficiency, thrombocytopenia, and eczema. The underlying T-cell defect renders renal transplantation and immunosuppressive treatments uncertain. The present case exhibited the mild clinical manifestation, regarded as X-linked thrombocytopenia. He successfully underwent a living-donor ABO-compatible renal transplantation and splenectomy in 2002, and thereafter experiencing no severe rejection, serious infection, or malignancy for more than 10 years. Though IgA nephropathy was detected 8 months after transplantation, the patient's renal function and proteinuria were stable without any treatment. The present case showed a successful long-term graft survival and the importance of splenectomy added to renal transplantation.

Outcomes of Kidney Transplantation from Circulatory Death Donors With Increased Terminal Creatinine Levels in Serum.

BACKGROUND: To alleviate chronic renal graft shortages in Japan, donation after circulatory death (DCD) is an increasingly used organ resource. Organs from DCD donors with progressively increased terminal creatinine (t-Cr) levels are frequently used, but the effects of this condition on kidney transplantation (KTx) remain unclear. METHODS: Between 1996 and 2013, 99 KTx from DCD donors were conducted in our department. Recipients were grouped according to the t-Cr (in mg/dL) of donors: group 1, t-Cr less than < 1.5; group 2, 1.5 ≤ t-Cr < 3.0; and group 3, t-Cr ≥ 3.0. We analyzed the long-term outcomes of KTx from DCD donors retrospectively in terms of donors' terminal renal function. RESULTS: The respective mean donor t-Cr in groups 1, 2, and 3 were 0.73 ± 0.28, 2.02 ± 0.40, and 6.69 ± 3.68. The respective death-censored graft survival rates (%) in groups 1, 2, and 3 were 90.2, 96.2, and 86.7 at 1 year and 70.3, 86.2, and 73.4 at 10 years after transplantation. Group 1 exhibited lower incidence of delayed graft function than either group 2 or group 3 (80.5% vs 100% and 93.3%). Nevertheless, no significant difference was found between groups for several measures: Cr levels 1 month after KTx and lowest Cr levels throughout the observation period, prevalence of biopsy-proven acute rejection, and graft survival. Cox proportional hazard regression showed that donor age, cerebrovascular event, terminal urine output, and history of hypertension were significantly associated with graft survival. CONCLUSIONS: Results suggest that, under certain conditions, kidneys from DCD donors with progressively increased t-Cr can be used safely with promising long-term outcomes.

Nine-yr experience of 700 hand-assisted laparoscopic donor nephrectomies in Japan.

OBJECTIVE: We reviewed the introduction of a new, minimally invasive, live kidney donation program in our department. METHODS: The operating times of 700 consecutive hand-assisted laparoscopic donor nephrectomies (HALDN) conducted from February 2001 to April 2010 were examined. The risk factors for prolonging operating times were analyzed and major surgical barriers in HALDN investigated. RESULTS: All procedures were successfully performed without the requirement for conversion to open surgery or blood transfusion. The overall prevalence of perioperative complications was 3.0%, with no mortality, in this non-obese donor population with mean body mass index (BMI) as low as 23.2 ± 3.2 kg/m(2) . After the initial learning curve, a second learning plateau was detected until around case 300. Multivariate analyses showed that the significant risk factors were male sex, graft weight, number of renal arteries, right nephrectomy, and previous epigastric surgery (p < 0.05). HALDN provided direct handling of the surgical field, secure vascular control, safe manipulation of adhesive tissues, and served to maintain surgical safety. Mean values of the BMI of donors had a significant positive correlation with the prevalence of complications between large studies (p = 0.042). CONCLUSIONS: Laparoscopic donor nephrectomy was safely introduced and established in a single institution with the help of the hand-assistance method.