Intravoxel Incoherent Motion-Diffusion-Weighted MRI for Investigation of Delayed Graft Function Immediately after Kidney Transplantation.

Purpose: A non-invasive way of assessing post-transplant renal graft function has been needed. This study aimed to assess the micro-structural and micro-functional status of graft kidneys by using intravoxel incoherent motion- (IVIM-) diffusion-weighted imaging (DWI) to investigate delayed graft function (DGF) immediately after transplantation. Method: A prospective study was conducted on 37 patients, 14 with early graft function (EGF) and 23 with DGF (9 with complication, 14 without) who underwent IVIM-DWI, most often within 1-7 days after kidney transplantation. A total of 37 cases were collected and all the participants have been well-informed and signed their consents. In addition, the study conducted in this paper was approved by the Ethics Committee of Clinical Research, Taichung Veterans General Hospital (IRB number: CE14065). Using biexponential analysis of slow diffusion coefficient (D slow), fast diffusion coefficient (D fast), and perfusion fraction was performed. The apparent diffusion coefficient (ADC) was calculated by use of a monoexponential model. All parameters were measured from three different regions-of-interest (ROI), covering the entire renal parenchyma, cortex, and medulla. Results: D slow, perfusion fraction, and ADC were significantly higher in patients with EGF than DGF (all p values values <0.001). Especially, ADC measured from ROI covering the entire kidney parenchyma had the best cut-off value (1.93µm2/msec) with the highest area under the receiver operating characteristic curve (AUC 0.943) in differentiating EGF from DGF. For analysis of pair-wise differences, only the perfusion fraction values, measured from the ROI covering the renal cortex, were significantly higher in 14 DGF patients with no complications than in the 9 DGF patients with complications, with the best cut-off value of 12.3% and the AUC of 0.844. Conclusion: Noninvasive IVIM-DWI reliably differentiates DGF from EGF after kidney transplantation, and it may aid in identifying posttransplant complications and indications for renal biopsy.

Contrast-enhanced CT texture analysis for the prediction of delayed graft function following kidney transplantation from cadaveric donors.

OBJECTIVE: Delayed graft function (DGF) is a common complication after transplantation of deceased donor kidneys. The aim of this study was to investigate the feasibility of using computed tomography texture analysis (CT-TA) of the donor kidney to predict delayed graft function (DGF) following kidney transplantation from cadaveric donors. MATERIALS AND METHODS: We made a retrospective review of all consecutive DBD and DCD kidney donors admitted to our institution and their corresponding KTRs between December 2014 and January 2019. We extracted 15 image features from unenhanced CT and contrast-enhanced CT corresponding to first order and second order Haralick textural features. Predictors of DGF were evaluated by univariable and multivariable analysis. Receiver operating characteristic (ROC) analysis was performed and the area under the ROC curve (AUC) to predict DGF was calculated for the predictors. RESULTS: A total of 115 patients were included in the study. DGF occurred in 15 patients (13%). Recipient body mass index (BMI) (P=0.003) and Skewness (P=0.05) represented independent predictors in the multivariate model. The combination of both clinical and textural features in a bivariate model reached a ROC-AUC of 0.79 (95% CI: 0.64-0.94) in predicting the probability of DGF. CONCLUSION: Results from this preliminary study suggest that CT texture analysis might be a promising quantitative imaging tool to help physician predict DFG after kidney transplantation from cadaveric donors. LEVEL OF EVIDENCE: 4/5.

Value of Baseline Post-Transplant MAG3 Renal Scintigraphy in the Evaluation of Graft Function.

INTRODUCTION: Accurate assessment of renal graft function in the early post-transplant period is crucial, as it influences clinical management and graft prognostication. However, there are limitations in current available modalities. MAG3 scintigraphy could contribute vital information on graft function. OBJECTIVES: This study aimed to determine the predictive value of parameters derived from MAG3 performed within 72 hours post transplant in detecting graft function. Delayed graft function (DGF), which is defined as dialysis requirement within the first week post transplant, is chosen as a surrogate measure of graft function. METHODOLOGY: All renal transplant recipients who underwent MAG3 within 72 hours post transplant from 2017 to 2019 were enrolled. Three MAG3 parameters, renogram grade, tubular injury severity score, and R20:3, were evaluated. RESULTS: A total of 117 patients were enrolled. The overall incidence of DGF was 16.2% with a significantly higher incidence amongst cadaveric graft recipients (53.6%) compared with living graft recipients (4.5%). Renogram grade ≥2, tubular injury severity score ≥4, and R20:3 > 1.31 significantly predicted DGF, P < .05 with high area under the curve for R20:3 of 0.97. Grafts with parameters above the cutoffs also showed significantly worse GFR at 1- and 3-months post-transplant. On multivariate analysis, prolonged cold ischemia time was associated with a higher risk of DGF, odds ratio 1.005 (95% confidence interval 1.003-1.007), P < .05. CONCLUSION: Baseline MAG3 accurately depicts early graft function and was also predictive of GFR at 1- and 3- months post-transplant. These baseline MAG3 scans could be particularly useful amongst deceased donor graft recipients owing to the higher risk of poor graft function.

Reduced Flow in Delayed Graft Function as Assessed by IVIM Is Associated With Time to Recovery Following Kidney Transplantation.

BACKGROUND: Delayed graft function (DGF), defined as the need for dialysis in the first week after kidney transplantation, frequently complicates posttransplantation care. The most common cause of DGF is ischemia-reperfusion injury (IRI). To date, no clinical tools can accurately estimate its severity, nor the time required for recovery of kidney function. PURPOSE: To investigate if parameters related to directed flow and diffusion of water, as determined by intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI), could be used to differentiate DGF from normal graft function posttransplantation, predict time to recovery from DGF, and hence serve as a surrogate measure of IRI severity. STUDY TYPE: Prospective, cross-sectional cohort study. POPULATION: Fifty consecutive kidney transplant recipients within 3-10 days posttransplantation at our hospital. FIELD STRENGTH/SEQUENCE: 3.0T/IVIM-DWI. ASSESSMENT: The following IVIM-DWI parameters were studied: flow-fraction (f), apparent diffusion coefficient (ADC), and total-ADC (ADCT ). Mean intrarenal resistive index (R.I.) from Doppler ultrasound was also included for a comparison of IVIM-DWI with the clinical standard of care. STATISTICAL TESTS: Welch's t-test, Spearman's correlation, and linear regression. RESULTS: f was significantly reduced in DGF compared to non-DGF patients in the cortex, medulla, and whole renal parenchyma (P < 0.05). Time to recovery with respect to MRI correlated negatively with f (P < 0.05; rho = -0.52 (cortex), and -0.65 [parenchyma]), ADC (P < 0.05; rho = -0.59 [cortex], 0.59 [medulla], and -0.59 [parenchyma]) and ADCT (P < 0.05; rho = -0.54 [cortex], and -0.52 [medulla]). Whole renal parenchymal f predicted time to recovery relative to MRI (P < 0.05, adjusted r-squared = 0.36). R.I. was significantly different between the groups but did not correlate with time to recovery with respect to MRI (rho = 0.43, P = 0.096). DATA CONCLUSION: Quantification of renal flow using IVIM-DWI has the potential to serve as a surrogate measure of IRI severity to estimate the degree of and recovery from DGF. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.

Predictive Value of Intraoperative Doppler Flowmetry for Delayed Graft Function in Kidney Transplantation: A Pilot Study.

BACKGROUND: The delayed graft function (DGF) in kidney transplantation (KT) is a risk factor for long-term poor graft survival. The pathogenesis is multifactorial but mainly related to an ischemia-reperfusion injury. However, the graft hemodynamics have been recently identified as a key aspect for early DGF risk assessment and potential therapeutic intervention. METHODS: A pilot study on 20 single kidney grafts from donor after brain death with intraoperative measurement of graft arterial flowmetry, 30 minutes after reperfusion. Exclusion criteria were grafts with multiple arteries or severe atherosclerosis of the recipient's external iliac artery. RESULTS: KT recipients with DGF (n = 4, 20%) were homogenous with controls (n = 16) in terms of cold ischemia time, donor age, recipients' hemodynamic parameters, renal artery, and recipients' external iliac artery diameters. Nonetheless, at transplant, the kidney grafts that developed DGF were characterized by a significantly higher renal artery resistive index (DGF vs no-DGF 0.96 ± 0.04 vs 0.77 ± 0.13, P = .02), as well as lower flow extraction rate (24.8% ± 11.8 vs 59.2% ± 21.1, P < .01). CONCLUSIONS: Intraoperative arterial graft flowmetry seems to be an effective tool to identify grafts at high risk of DGF.

Kidney allograft dysfunction due to ipsilateral thigh arteriovenous graft.

Arteriovenous graft in the thigh is used not infrequently for hemodialysis. Outcomes with this lower extremity dialysis access are generally comparable to upper extremity access and superior to long-term catheter use. However, it could have significant implications in a patient getting a kidney transplant. Here we describe a case of thigh arteriovenous graft causing kidney allograft dysfunction in a new transplant recipient, and this resolved with graft ligation.

Limited clinical value of two consecutive post-transplant renal scintigraphy procedures.

OBJECTIVES: Duration of delayed graft function (DGF) and length of hospital stay (LOS) are outcomes of interest in an era that warrants increased efficacy of transplant care whereas renal allografts originate increasingly from marginal donors. While earlier studies investigate the predictive capability of a single renal scintigraphy, this study focuses on the value for both DGF duration and LOS of consecutively performed scintigraphies. METHODS: From 2011 to 2014, renal transplant recipients referred for a Tc-99m MAG3 renal scintigraphy were included in a single-center retrospective study. Primary endpoints were DGF duration and LOS. Both the first (≤ 3 days) and second scintigraphies (3-7 days after transplantation) were analyzed using a 4-grade qualitative scale and quantitative indices (TFS, cTER, MUC10, average upslope). RESULTS: We evaluated 200 first and 108 (54%) consecutively performed scintigraphies. The Kaplan-Meier curves for DGF duration and qualitative grading of the first and second scintigraphy showed significant differences between the grades (p < 0.01). The Kaplan-Meier curve for the delta grades between these procedures (lower, equal, or higher grade) did not show significant differences (p = 0.18). Multivariate analysis showed a significant association between the qualitative grades, from the first and second scintigraphy, and DGF duration, HR 1.8 (1.4-2.2, p < 0.01) and 2.8 (1.8-4.3, p < 0.01), respectively. CONCLUSIONS: Qualitative grades of single renal scintigraphies, performed within 7 days after transplantation, can be used to make a reliable image-guided decision on the need for dialysis and to predict LOS. A consecutive renal scintigraphy, however, did not show an additional value in the assessment of DGF. KEY POINTS: • Post-transplant renal scintigraphy procedures provide information to predict delayed graft function duration and length of hospital stay. • Performing two consecutive renal scintigraphy procedures within 1 week after transplantation does not strengthen the prediction of delayed graft function duration and length of hospital stay. • Single renal scintigraphy procedures can be used to provide clinicians and patients with a reliable indication of the need for dialysis after transplantation and the expected duration of hospitalization.

Live Confocal Tissue Assessment With SYTO16/PI and WGA Staining Visualizes Acute Organ Damage and Predicts Delayed Graft Function in Kidney Transplantation.

OBJECTIVE: The aim of our prospective clinical trial was to test a tissue staining technique (real-time confocal analysis [RTCA]) as a rapid assessment tool for donor kidney quality and function in human kidney transplantation. SUMMARY BACKGROUND DATA: Tools for objective graft tissue viability assessment before kidney transplantation are lacking. RTCA has recently been established and tested in a pilot study using rodent kidneys. METHODS: RTCA was performed in kidney biopsies stained with SYTO16/PI and WGA. A score between -3 (100% nonviable) and +3 (100% viable) describes the sum of viable cells divided by the number of nonviable cells per examined area (glomerulus, proximal, and distal tubules). The primary study endpoint was the delayed graft function (DGF). RESULTS: Seventy-one kidney transplant recipients were transplanted. The median recipient and donor age were 58.5 and 57 years, respectively. Cold ischemia time was 13.6 ±â€Š4.7 hours; anastomosis time was 30.8 ±â€Š8.7 minutes (mean ±â€ŠSD). Overall, 23 (33.8%) patients developed DGF. The RTCA score was significantly lower in kidneys developing DGF -0.43 ±â€Š1.78 versus no DGF 0.91 ±â€Š2.17, P = 0.01. The Remuzzi score did not differ between DGF and no DGF, P = 0.13. Remuzzi score and RTCA score correlate inversely significantly; P = 0.004. In the multivariate analysis, solely RTCA score was revealed as a significant independent factor predicting DGF; P = 0.015, Wald = 5.95, odds ratio = 0.72, 95% confidence interval = 0.55 to 0.94. CONCLUSIONS: Our data demonstrate that RTCA is feasible and clinically meaningful. The RTCA score predicts DGF and is a valid option to be applied in renal transplantation.

Association between Early Resistive Index Measurement and Early Graft Function and Long-Term Graft Survival after Kidney Transplantation: an Evidence-based Clinical Review.

BACKGROUND: resistive index (RI) is highly utilised to assess the graft function using Doppler ultrasonography. The RI has been shown as the best ultrasound parameter to assess kidney allograft dysfunction. Several studies have established the role of the RI as a predictor of transplant failure. However, these studies were using RI measurement in the later stages post transplantation. The present study has conducted to identify the association between early RI measurement and early graft function represented as delayed graft function (DGF) and immediate graft function (IGF), as well as long-term graft survival. METHODS: an evidence-based clinical review of studies published before May 2018 was conducted from Medline, Science Direct, EMBASE and Cochrane databases. Studies on early measurement of RI whereby the primary or secondary goals of the study related to graft function and/or graft survival were included. Studies using late RI measurement and without RI value groups were excluded. The Mantzel-Haenzel method was used to analyse pooled risk ratio and 95% confidence interval, while the heterogeneity of the study was calculated through I2 value. Data analysis was performed using Review Manager 5.3. RESULTS: nine studies with a total of 1802 patients who had undergone a kidney transplant were analysed. DGF was found in 19% (193/1015) of the low RI group and in 42.8% (337/787) of the high RI group (RR 2.04 (95% CI 1.72 - 2.41), p < 0.00001, I2 = 28%). IGF was found in 39.5% (62/157) of the low RI group and in 10.5% (28/268) of the high RI group (RR 0.26 (95% CI 0.17 - 0.40), p < 0.00001, I2 = 0%). Long-term graft survival, with follow up between 60-144 months, was found in 83% (701/845) of the low RI group and in 69.4% (395/569) of the high RI group (RR 0.82 (95% CI 0.72 - 0.93), p = 0.002, I2 = 63%). CONCLUSION: the results of this study emphasise the association between early measurement of RI and early graft function, and long-term graft survival. An elevated RI provides the chance of recognizing the patients with poor long-term prognosis, from the first moment after kidney transplant.

Practical Method for Calculation of Graft Index in Renal Transplant Scintigraphy: A Technical Note.

Some quantitative indices have been described for renal transplant scintigraphy in evaluating graft dysfunction, some medical complications, and in predicting early and delayed graft function and long-term graft prognosis. Graft index is very useful and more accurate than many other indices in the prediction of delayed graft function and long-term prognosis. In this technical note, the method of calculation of graft index is shown in detail for the authors who want to use this index in further studies or in clinical practice.

Assessment of delayed graft function using susceptibility-weighted imaging in the early period after kidney transplantation: a feasibility study.

PURPOSE: This study aimed to explore the feasibility of susceptibility-weighted imaging (SWI) for evaluating delayed graft function (DGF) during the early posttransplantation period. METHODS: Sixty-nine recipients who accepted allograft renal transplantation underwent SWI during the second posttransplantation week. Renal allograft function was estimated via the glomerular filtration rate. Recipients with and without DGF were identified. For each transplanted kidney, the presence of abnormal signal intensity lesions (ASILs), excluding benign lesions, on SWI was assessed. Renal allograft function was compared between the recipients with and without ASILs. The correlation between ASILs and renal allograft function was tested by Spearman's rank correlation analysis. RESULTS: Thirty-four recipients were diagnosed with DGF, while 35 recipients showed no DGF. In the DGF group, 16 recipients had low-intensity ASILs, primarily at the corticomedullary junction of transplanted kidneys on SWI, and no ASILs were found in 18 recipients. In the non-DGF group, none of the recipients showed ASILs on SWI. In the DGF group, the renal allograft function among the 16 recipients with low-intensity ASILs was significantly lower than that among the other 18 recipients (8.5 ± 4.2 vs. 19.7 ± 9.7 mL/min, P < 0.001). The presence of low-intensity ASILs on SWI showed a moderate negative correlation with renal allograft function in recipients with DGF (r = - 0.553, P = 0.001). CONCLUSION: SWI can be used to evaluate DGF in the early post-kidney transplantation period.

Time-intensity curve analysis of contrast-enhanced ultrasound is unable to differentiate renal dysfunction in the early post-transplant period - a prospective study.

BACKGROUND: Contrast enhanced ultrasonography (CEUS) assessment of kidney allografts mainly focuses on graft rejection. However, studies on delayed graft function (DGF) without acute rejection are still lacking. The aim of this study was to build a time-intensity curve (TIC) using CEUS in non-immunological DGF to understand the utility of CEUS in early transplantation. METHODS: Twenty-eight patients in the short-term postoperative period (<14 days) were divided according to the need for dialysis (early graft function [EGF] and [DGF]) and 37 subjects with longer than 90 days follow-up were divided into creatinine tertiles. Time to peak [TTP] and rising time [RT were compared between groups. RESULTS: EGF and DGF were similar, except for creatinine. In comparison to the late group, medullary TTP and RT were shorter in the early group as well as the delay regarding contrast arrival in the medulla (in relation to cortex) and reaching the medullary peak (in relation to artery and cortex). In the late group, patients with renal dysfunction showed shorter temporal difference to reach medullary peak in relation to artery and cortex. CONCLUSIONS: Although it was not possible to differentiate EGF and DGF using TIC, differences between early and late groups point to blood shunting in renal dysfunction.

Early predictive value of baseline renal transplant scintigraphy in pediatric patients.

OBJECTIVES: The value of baseline renal transplant scintigraphy (RTS) with technetium-99m diethylenetriaminepentaacetic acid (Tc-DTPA) performed within 2 days after transplantation in predicting early renal transplant outcome in pediatric recipients was assessed in this study. PATIENTS AND METHODS: Baseline RTS of 48 pediatric patients were studied retrospectively. Hilson's perfusion index, graft index (GI), time between peak perfusion and iliac artery (ΔP), and the ratios of peak perfusion to plateau (P : Pl), to peak iliac artery (P : A), and to peak uptake (P : U) were obtained. In 14 patients younger than 9 years old, because of faint visualization of iliac artery, the perfusion indices and GI could not be calculated. The 'Bedside Schwartz' formula was used for calculation of follow-up estimated glomerular filtrate rate (eGFR) values. The need for dialysis in the first week or decreasing serum creatinine of less than 10%/day during 3 consecutive days after the transplantation was accepted as delayed graft function (DGF). The patients, whose creatinine reduction ratio was less than 70% on day 7 after transplantation without DGF, were accepted as slow graft function (SGF). RESULTS: The means of GI, P : U, and Hilson's perfusion index were significantly high in SGF/DGF (n=10). GI and P : U had very high accuracy in the diagnosis of DGF/SGF (area under the curve>0.90). A strong correlation was found between P : U and same day and between GI and day 15 eGFR values. GI, P : U, and P : A were significant for the prediction of follow-up eGFR of less than 60 ml/min/1.73 m. GI was more accurate than the others. CONCLUSION: Our experience in this study underlines the importance of RTS, especially with the use of GI and P : U, which are very valuable in diagnosing DGF/SGF and predicting early transplant outcome in pediatric recipients.

Can transplant renal scintigraphy predict the duration of delayed graft function? A dual center retrospective study.

INTRODUCTION: This study focused on the value of quantitatively analyzed and qualitatively graded renal scintigraphy in relation to the expected duration of delayed graft function after kidney transplantation. A more reliable prediction of delayed graft function duration may result in a more tailored and patient-specific treatment regimen post-transplantation. METHODS: From 2000 to 2014, patients with early transplant dysfunction and a Tc-99m MAG3 renal scintigraphy, within 3 days post-transplantation, were included in a dual center retrospective study. Time-activity curves of renal scintigraphy procedures were qualitatively graded and various quantitative indices (R20/3, TFS, cTER, MUC10) were combined with a new index (Average upslope). The delayed graft function duration was defined as the number of days of dialysis-based/functional delayed graft function. RESULTS: A total of 377 patients were included, with a mean age (± SD) of 52 ± 14 years, and 58% were male. A total of 274 (73%) patients experienced delayed graft function≥ 7 days. Qualitative grading for the prediction of delayed graft function≥ 7 days had a sensitivity and specificity of respectively 87% and 65%. The quantitative indices with the most optimal results were cTER (76% sensitivity, 72% specificity), and Average upslope (75% sensitivity, 73% specificity). CONCLUSIONS: Qualitative renal scintigraphy grading and the quantitative indices cTER and Average upslope predict delayed graft function ≥ 7 days with a high sensitivity. This finding may help to support both clinicians and patients in managing early post-operative expectations. However, the specificity is limited and thus renal scintigraphy does not reliably help to identify patients in whom the course of delayed graft function is longer than anticipated.

Proton Nuclear Magnetic Resonance (¹H-NMR)-Based Metabolomic Evaluation of Human Renal Allografts from Donations After Circulatory Death.

BACKGROUND Delayed graft function (DGF) is a common complication that impairs allograft function after kidney transplantation. However, the mechanism of DGF remains unclear. Nuclear magnetic resonance (NMR)-based analysis has been widely used in recent times to assess changes in metabolite levels. MATERIAL AND METHODS Samples of perfusate from allografts donated after circulatory death were collected prior to transplantation, during static cold storage. ¹H-NMR-based metabolomics combined with the statistical methods, orthogonal partial least-squares discriminant analysis (OPLS-DA), and principle-component analysis (PCA), were employed to test different levels of metabolites between the allografts that exhibited DGF and those that exhibited immediate graft function (IGF). RESULTS The study population consisted of 36 subjects, 11 with DGF and 25 with IGF. Of the 37 detected and identified metabolites, a-glucose and citrate were significantly elevated in the perfusate of DGF allografts, and taurine and betaine were significantly decreased. CONCLUSIONS ¹H-NMR analysis of DGF and IGF perfusates revealed some significant differences in their metabolite profiles, which may help explain the mechanisms of kidney ischemia-reperfusion injury and DGF.

Surgical Repair of a Living-Donor Kidney Graft Artery Kink by a Postanastomotic External Iliac Artery Rotation and Reanastomosis.

A 61-year-old man received a living-donor kidney graft for an end-stage renal disease. In the postoperative course, the patient was oliguric and needed dialysis. The postoperative Doppler showed a normal peak systolic velocity and maintained parenchymal perfusion associated with a parvus tardus signal. The patient was operated, and a kinked renal artery was found. To reposition the artery, the distal iliac artery was clamped, sectioned, shortened, and reanastomosed after a 90° axial rotation. This innovative technic allowed restoration of a normal flow in the parenchyma and avoided an additional clamping, cooling, ischemia, and reanastomosis/reperfusion of the graft. Postoperative diuresis immediately raised >100 mL/hr and creatinine durably returned to normal values.

Immediate Vascular Complications After Kidney Transplant: Experience from 2100 Recipients.

OBJECTIVES: Vascular complications, especially immediate events during kidney transplant, are the major cause of graft loss, and prompt surgical intervention is important for salvage of the graft and recipient. In this study, our aim was to show our experiences with vascular interventions and their effects on graft outcomes in transplant patients with suspected immediate vascular events. MATERIALS AND METHODS: Over 24 years (from 1990 to 2014), 2100 renal transplant procedures (1562 living and 538 deceased donors) were performed by one fixed team. We reviewed the recipients to find cases with immediate vascular complications, including artery or vein kinking or torsion, renal artery thrombosis, and renal vein thrombosis. Diagnosis of a vascular event was suspected when urinary output suddenly stopped and was confirmed by color Doppler ultrasonography or immediate exploration. Characteristics of the patients and events, surgical interventions for saving grafts, and graft outcomes were assessed. RESULTS: Our study included 28 vascular accidents (1.3% of total renal transplants). Arterial kinking or torsion, venous kinking or torsion, renal artery thrombosis, and renal vein thrombosis occurred in 11 (0.52%), 2 (0.09%), 12 (0.57%), and 3 patients (0.14%). Nine of the 11 cases of arterial kinking occurred with use of internal iliac artery. Eleven of 13 grafts with vascular kinking or torsion were saved by immediate surgical intervention, but only 4 grafts in patients with renal artery thrombosis and only 1 graft in patients with renal vein thrombosis were saved by surgical intervention. Delayed graft function occurred in all cases of saved renal artery and renal vein thrombosis but only in 5 cases (4 arterial and 1 venous) of vascular kinking or torsion. CONCLUSIONS: The incidence of immediate vascular complications was 1.3% in our study. Sudden cessation of urine after renal transplant is a warning sign, and immediate diagnosis of vascular events will help salvage the graft with proper intervention.

A New Quantitative Index for Baseline Renal Transplant Scintigraphy With 99mTc-DTPA in Evaluation of Delayed Graft Function and Prediction of 1-Year Graft Function.

PURPOSE: The aims of this study were to assess quantitative indices of baseline renal transplant scintigraphy (RTS) with Tc-DTPA for evaluation of delayed graft function (DGF) and prediction of 1-year graft function and to describe a new inclusive index for RTS. PATIENTS AND METHODS: A total of 179 patients to whom RTS with Tc-DTPA was performed within 2 days after kidney transplantation were analyzed retrospectively. Hilson perfusion index, perfusion time (ΔP), peak-to-plateau ratio, peak perfusion-to-iliac artery ratio, T½ of graft washout, peak perfusion-to-uptake ratio, and ratio of uptake at 20 to 3 minutes (R20/3) were obtained. In addition, we first described the following formula defined as graft index (GI): GI = (ΔP × arterial peak × plateau)/(perfusion peak × uptake at 3 minutes). At 1 year, a serum creatinine level of more than 1.5 mg/dL was considered to be abnormal. Mann-Whitney U, Spearman coefficient of correlation test, and receiver operating characteristic curve were used for statistical analyses. P < 0.05 was considered statistically significant. RESULTS: Mean values of all the indices were significant. The most accurate, sensitive, and specific index for both identification of DGF and prediction of 1-year serum creatinine level of more than 1.5 mg/dL was GI. Area under the curve of GI was 0.94 for identification of DGF and 0.79 for 1-year prediction. CONCLUSIONS: The question is, "Which index is the best indicator?" This study demonstrated that the parameters of ΔP, plateau, arterial peak, perfusion peak, and uptake at 3 minutes of RTS could be assessed together by the formula of GI, which provides more accurate information to identify DGF and predict 1-year graft function.

Role of allograft nephrectomy following kidney graft failure: preliminary experience with pre-operative angiographic kidney embolization.

INTRODUCTION: Allograft nephrectomy (AN) is not without morbidity following graft failure (GF) in kidney transplantation (KT). METHODS: Single center retrospective review of all adult patients undergoing AN following KT, including a subset of patients who underwent pre-operative angiographic kidney embolization (PAKE). RESULTS: Over a 104 month period, 853 adult patients underwent deceased donor KT. With a median follow-up of 3.5 years, 174 patients (20.4%) developed GF and 38/174 (21.8%) underwent AN. The rate of AN was higher in patients with delayed graft function [DGF, Odds Ratio (OR) 2.15, p = 0.023] and early GF (OR 1.7, p = 0.064). For patients undergoing PAKE (n = 13, mean timing of AN 27.5 months post-KT), the estimated intra-operative blood loss was reduced from a mean of 375 ± 530 to 100 ± 162 ml (p < 0.10), mean peri-operative transfusion requirements were reduced from 3.36 ± 4.8 to 0.23 ± 0.44 units (p < 0.05), and total mean operating time was reduced from 192 ± 114 to 141 ± 38 min (p = NS) compared to 13 control patients undergoing AN in the absence of vascular thrombosis or PAKE. Mean length of hospital stay was decreased from 8.5 ± 9 to 5.5 ± 3 days (p = NS) in patients with PAKE. Surgical complication and infection rates and hospital charges were comparable. CONCLUSIONS: Delayed graft function and early GF are associated with a higher rate of AN. PAKE may result in less blood loss, fewer transfusions, reduced operating time, and shorter length of stay, which may translate into reductions in morbidity.

Quantified power Doppler as a predictor of delayed graft function after renal transplantation.

PURPOSE: No safe ultrasound (US) parameters have been established to differentiate the causes of graft dysfunction. OBJECTIVES: To define US parameters and identify the predictors of normal graft evolution, delayed graft function (DGF), and rejection at the early period after kidney transplantation. METHODS: Between June 2012 and August 2013, 79 renal transplant recipients underwent US examination 1-3 days posttransplantation. Resistive index (RI), power Doppler (PD), and RI + PD (quantified PD) were assessed. Patients were allocated into three groups: normal graft evolution, DGF, and rejection. RESULTS: Resistive index of upper and middle segments and PD were higher in the DGF group than in the normal group. ROC curve analysis revealed that RI + PD was the index that best correlated with DGF (cutoff = 0.84). In the high RI + PD group, time to renal function recovery (6.33 ± 6.5 days) and number of dialysis sessions (2.81 ± 2.8) were greater than in the low RI + PD group (2.11 ± 5.3 days and 0.69 ± 1.5 sessions, respectively), p = 0.0001. Multivariate analysis showed that high donor final creatinine with a relative risk (RR) of 19.7 (2.01-184.7, p = 0.009) and older donor age (RR = 1.17 (1.04-1.32), p = 0.007) correlated with risk DGF. CONCLUSIONS: Quantified PD (RI + PD) was the best DGF predictor. PD quantification has not been previously reported.