Independent risk factors for early urologic complications after kidney transplantation

Approach to Kidney Allograft Dysfunction: A Brief Review

It is important for providers caring for kidney transplant recipients to be familiar with the common causes of allograft dysfunction. Early detection of allograft dysfunction leads to timely management, with the goal of preventing or delaying progression to allograft failure. Although transplant rejection is always a concern, the differential diagnoses for allograft dysfunction are broad and include perioperative complications, infections, recurrent disease, and calcineurin nephrotoxicity. In this review, we will go over early and late causes of allograft dysfunction and discuss the basic workup and principles of management for each condition.

Rectus sheath patch. A novel surgical technique in the repair of isolated renal pelvis necrosis in a transplanted kidney. A case report

INTRODUCTION

Focal necrosis of the renal pelvis in a transplanted kidney is a rare but often morbid complication that may lead to graft loss. Given the scarcity of donor organs, all attempts are made to preserve the graft. Currently there is no standard surgical technique for reconstruction or repair of isolated renal pelvic necrosis.

PRESENTATION OF CASE

A 70-year-old male with end stage kidney disease underwent renal transplantation. The patient developed a day-three post-operative urine leak. During surgical exploration, a focal area of pelvic necrosis was observed without evidence of proximal or distal ureteric involvement. Given the excellent function of the renal allograft, a novel surgical technique was successfully used to repair the necrotic defect. Reconstruction of the renal pelvis was performed using an avascular rectus sheath patch. The patch was secured over the open pelvis following necrotic tissue debridement. The patient made a successful recovery with complete resolution of urine leak. A 6-week post-operative retrograde pyelogram confirmed no ongoing urine leak.

DISCUSSION

To restore anatomy, the pelvic defect was patched with avascular rectus sheath fascia. Advantages of this reconstructive method were technique simplicity and low donor site morbidity. Potential complications included patch failure with ongoing urine leak, ventral wall hernia through the fascial donor site and stenosis of the ureteropelvic junction.

CONCLUSION

This case highlights the successful surgical management of a renal pelvis urine leak patched with rectus sheath fascia. This technique could be considered as a graft saving procedure in similar cases where the alternative is transplant nephrectomy.

The early outcomes of two separate anastomosis procedures in deceased kidney transplantation with double arteries: A retrospective comparative study

BACKGROUND

Kidneys with double renal arteries are used on a routine basis nowadays, and separate anastomosis in situ is one of the suitable arterial anastomosis procedures. The commonly used methods are parallel end-to-side anastomoses of double arteries to the external iliac artery, and end-to-end anastomosis to the internal iliac artery combined with end-to-side anastomosis to the external iliac artery. No studies have compared the prognoses of the two procedures in deceased kidney transplantation.

METHODS

We retrospectively analyzed 35 consecutive deceased kidney transplantations with double arterial anastomoses in the urology department of China-Japan Friendship Hospital from January 2018 to April 2021. Group I comprised recipients with double parallel end-to-side anastomoses to the external iliac artery; Group II comprised the others. Their prognoses were then compared.

RESULTS

There were no significant differences between Group I and II in characteristics of recipients and donors. The mean eGFRs at 1, 3, 6 and 12 months post-transplant in Group I and II were 36.4 vs 54.1 (P = 0.009), 40.4 vs 54.4 (P = 0.02), 40.4 vs 56.9 (P = 0.02) and 39.8 vs 57.9 (P = 0.007) mL/min respectively. There was no difference in early postoperative complications and 1-year survival rates between the two groups (P = 1.00).

CONCLUSION

Separate anastomosis is a reliable procedure for deceased kidney transplantation with double arteries. Double separate anastomoses to the external and internal iliac arteries have better graft function compared with double parallel anastomoses to the external iliac artery during the first year after transplantation.

Ureterovesical Leak Following Renal Transplant and Effects of Acute Rejection and Antirejection Therapy: A Nested Case-Control Analysis and Outcome of 1102 Consecutive Renal Transplant Recipients

OBJECTIVES

Studies on nontechnical risk factors for ureterovesical leak after renal transplant are scarce. This study aimed to report the possible pre- and postoperative risk factors and the role of acute rejection and antirejection therapies for urine leak after transplant and its effect on graft and patient survival.

MATERIALS AND METHODS

We conducted a retrospective analysis of 13 patients (1.17%) with urine leak (case group) and 52 patients without leak (control group) (case-to-control ratio of 1:4) from 1102 living related (first degree) renal transplant recipients seen between January 2012 and December 2021. We analyzed demographic and clinical details and biochemical and outcome parameters using a nested case-control design.

RESULTS

Cases were olderthan controls (P = .018), were more ABO incompatible (P = .009), and had more 6/6 HLA mismatch transplants (P = .047). Donors of cases were older than donors of controls (P = .049). The rate of postoperative hypoalbuminemia was greaterin the case group (P = .050). Rates of acute rejection (P = .012) and plasmapheresis (P = .003) were greaterin the case group than in the control group. On multivariate logistic regression analysis, recipient age, 6/6 HLA mismatch, and plasmapheresis were found to independently associated with urine leak. None ofthe patient required surgical repair, as all responded to conservative therapy. Urine leak did not affect graft outcomes (P = .324), but overall survival was less in cases than in controls.

CONCLUSIONS

Nontechnical risk factors that cause posttransplant ureteric leak include older donor and recipient age and ABO incompatible and 6/6 HLA mismatch transplants. Acute rejection and plasmapheresis predispose leak, and an indwelling double J stent can allow adequate healing of the anastomosis. High index of suspicion and prompt management are imperative to preserve graft and patient outcome.

Ureterovesical Anastomosis Complications in Kidney Transplantation: Definition, Risk Factor Analysis, and Prediction by Quantitative Fluorescence Angiography with Indocyanine Green

Ureteral stenosis and urinary leakage are relevant problems after kidney transplantation. A standardized definition of ureterovesical anastomosis complications after kidney transplantation has not yet been established. This study was designed to demonstrate the predictive power of quantitative indocyanine green (ICG) fluorescence angiography. This bicentric historic cohort study, conducted between November 2015 and December 2019, included 196 kidney transplantations. The associations between quantitative perfusion parameters of near-infrared fluorescence angiography with ICG and the occurrence of different grades of ureterovesical anastomosis complications in the context of donor, recipient, periprocedural, and postoperative characteristics were evaluated. Post-transplant ureterovesical anastomosis complications occurred in 18%. Complications were defined and graded into three categories. They were associated with the time on dialysis (p = 0.0025), the type of donation (p = 0.0404), and the number of postoperative dialysis sessions (p = 0.0173). Median ICG ingress at the proximal ureteral third was 14.00 (5.00–33.00) AU in patients with and 23.50 (4.00–117.00) AU in patients without complications (p = 0.0001, cutoff: 16 AU, sensitivity 70%, specificity 70%, AUC = 0.725, p = 0.0011). The proposed definition and grading of post-transplant ureterovesical anastomosis complications is intended to enable valid comparisons between studies. ICG Fluorescence angiography allows intraoperative quantitative assessment of ureteral microperfusion during kidney transplantation and is able to predict the incidence of ureterovesical anastomosis complications. Registration number: NCT-02775838.

Risk Factors for Urologic Complications After Kidney Transplantation and Impact in Graft Survival

Background and Purpose

Kidney transplantation (KT) is the best therapy for chronic kidney disease (CKD). Major urologic complications (MUCs) are the second etiology associated to morbidity and graft loss following KT, after rejection episodes. The objective of this study was to estimate the incidence, risk factors and impact on graft survival associated to urological complications in KT patients.

Patients and Methods

A retrospective cohort based on electronic patient files of kidney transplant recipients from Colombiana de Trasplantes was created for the period August 2008 to September 2019. Initiation of follow-up was defined as the date of transplantation up to 3 years post-transplantation. Incidence of ureteral stenosis, ureteral obstruction, and ureteral leak was measured. A logistic regression multivariate model was adjusted to determine the associated factors to MUCs (yes/no). Patient and graft survival time were analyzed using a Kaplan-Meier method.

Results

A total of 1584 KT patients were included in the cohort. MUCs were present in 195 (12.6%) KT patients. We found that dialysis duration (OR: 1.004; p = 0.02) remained significant for the incidence of MUCs in KT patients of deceased donors. Probability of graft and patient survival at 3 years of follow-up was 90.5% and 85.5%, respectively. No significant difference was found on graft and patient survival in KT patients with or without MUCs.

Conclusion

MUCs are frequent complications for KT. We did not observe significant differences in graft or patient survival according to the presence of MUCs. The identification of MUCs and risk factors may guide transplant teams for future surgical and clinical decisions.

Transplant Ureteral Stenosis after Renal Transplantation: Risk Factor Analysis

INTRODUCTION

The results of kidney transplants have improved dramatically in recent years, leading to reduced morbidity and mortality. Despite continuous improvements, urological complications occur at a rate of 2.6%-15%. Ureteral stenosis of graft ureters is the most common complication, with a probability of 0.5%-6.3%. This study aimed to determine the incidence of ureteral stenosis after kidney transplantation and identify risk factors that distinguish transplant patients with and without ureteral stenosis.

METHODS

This study retrospectively analyzed patients who had undergone kidney transplantation at the Department of Urology of the Friedrich-Alexander University Erlangen-Nuremberg between 2001 and 2015. Forty-seven patients developed ureteral stenosis during the operation. Most of the ureteral stenosis cases occurred in the first 4 months after transplantation. Kaplan-Meier analysis and the log-rank test were used to calculate the cumulative risk, and the Mann-Whitney U test was used nonparametrically. The significance level was set at p < 0.05.

RESULTS

Statistical analysis showed that residual diuresis (p = 0.008), cold ischemia time (CIT) (p = 0.040), the body mass index (p = 0.027), and donor serum creatinine value (p = 0.039) showed a significantly different distribution between recipients with or without ureteral stenosis after kidney transplantation. In multivariate Cox's regression modeling, residual diuresis and the donor serum creatinine level were identified as the only independent predictors of patients' stenosis-free survival.

CONCLUSION

Urological complications not diagnosed and treated in time endanger the success of kidney transplantation. After evaluating the kidney transplantation data of the patients at the Transplant Center Erlangen-Nuremberg from 2001 to 2015, residual diuresis, CIT, the body mass index, and donor serum creatinine value were found to influence the development of ureteral stenosis.

Kidney transplantation from expanded criteria donors: an increased risk of urinary complications - the UriNary Complications Of Renal Transplant (UNyCORT) study

OBJECTIVES

To assess the impact of expanded criteria donors (ECD) on urinary complications in kidney transplantation.

PATIENTS AND METHODS

The UriNary Complications Of Renal Transplant (UNyCORT) is a cohort study based on the French prospective Données Informatisées et VAlidées en Transplantation/Computerized and VAlidated Data in Transplantation (DIVAT) cohort. Data were extracted between 1 January 2002 and 1 January 2018 with 1-year minimum follow-up, in relation to 44 pre- and postoperative variables. ECD status was included according to United Network for Organ Sharing (UNOS) definition. The primary outcome of the UNyCORT study was the association between the donor's ECD/standard criteria donors (SCD) status and urinary complications at 1 year in uni- and multivariate analysis. Sub-group analysis, stratified analysis on ECD/SCD donor's status and transplant failure analysis were then conducted.

RESULTS

Between 1 January 2002 and 1 January 2018, 10 279 kidney transplants in adult recipients were recorded within the DIVAT network. A total of 8559 (83.4%) donors were deceased donors and 1699 (16.6%) were living donors (LD). Among donation after circulatory death (DCD) donors, 224 (2.85%) were uncontrolled DCD and 93 (1.09%) were controlled DCD donors. A total of 3617 (43.9%) deceased donors were ECD. The overall urological complication rate was 16.26%. The donor's ECD status was significantly associated with an increased risk of urological complications at 1 year in multivariate analysis (odds ratio: 1.50, 95% CI 1.31-1.71; P < 0.001) and especially with stenosis and ureteric fistulae at 1 year. There is no association with LD, uncontrolled and controlled DCD. The placement of an endo-ureteric stent was beneficial in preventing urinary complications in all donors and particularly in ECD donors.

CONCLUSION

The donor's ECD status is associated with a higher likelihood of stenosis and ureteric fistulae at 1 year. Recipients of grafts from ECD donors should probably be considered for closer urological monitoring and systematic preventive measures.

Complex Ureteral Reconstruction in Kidney Transplantation

OBJECTIVES

Despite advances in surgical techniques and organ preservation, transplant ureteric strictures remain a common complication in kidney transplantation. A variety of endourological and surgical techniques have been utilized; however, there is a lack of consensus on the optimal modality in dealing with these complex cases.

MATERIALS AND METHODS

We present challenging ureteral reconstruction cases after failed attempts at ureteral dilatation, failed conventional open repairs, and/or with bladder dysfunction.

RESULTS

All renal allografts were salvaged by successful use of bladder Boari flap and intestinal segment interpositions/diversions.

CONCLUSIONS

Operative repair remains the most durable and successful approach, and minimally invasive options should be reserved for nonsurgical candidates, with consideration of a single attempt in patients with early, distal, short (<2 cm), nonischemic strictures.

Risk Factors of Ureteral Stenosis in Kidney Transplant Recipients: A Retrospective Study in National Referral Hospital in Indonesia

Ureteral stenosis is one of the most common urological complications following kidney transplantations. It is occurred in 2–10% of patients and poses a significant problem to the patients as it may lead to permanent damage to renal damage. Identification of risk factors is important to prevent the incidence of ureteral stenosis. Thus, we aim to determine the risk factors of ureteral stenosis in the Indonesian population. This is a retrospective analysis of 487 kidney transplant patients performed in Cipto Mangunkusumo Hospital between 2014 and 2018. We collected and compared donor and recipient demography data in recipients who developed ureteral stenosis and recipients who did not develop ureteral stenosis. Ureteral stenosis was defined as the presence of hydronephrosis from ultrasound and increased number of serum creatinine. The overall incidence of ureteral stenosis post-kidney transplantation in our center is 6.6% (32 from 487 patients) from January 2014 until June 2018. We found that older donor and recipient age more frequent in developing ureteral stenosis post-kidney transplantation (p < 0.001). We also found that donors with number of arteries more than 2 (p < 0.001) and prolonged warm ischemic time (p < 0.05) are more frequently to develop ureteral stenosis post-kidney transplantation. There is no association between type II diabetes mellitus and hypertension with ureteral stenosis in this study. Donor age, recipient age, donor number of arteries more than 2, and prolonged warm ischemia time are associated with ureteral stenosis after kidney transplantation.

Urological Complications in Kidney Transplant Recipients: Analysis of the Risk Factors and Impact on Transplant Outcomes in the Era of “Extended Criteria Donors”

Urological complications (UC) following kidney transplantation (KT) are associated with increased morbidity. The aim of this study is to evaluate the risk factors for UC in the era of “extended criteria donors” (ECD) and their impact on patient and graft survivals. A retrospective monocentric study of all patients undergoing KT from 2010 to 2019 with a follow-up ≥30 days was performed. Out of 459 patients (males: 296 (64.5%); age: 57 (19–77) years) enrolled, 228 (49.7%) received ECD organs, moreover, 166 (67.2%) grafts had a cold ischemia time ≥10 h. UCs were reported in 32 (7%) patients. In 21 (65.6%) cases UC occurred within 3 months post-KT and 24 (5.2%) were associated with early urinary tract infection (UTI). The overall 5 year patient and graft survival rates were 96.5% and 90.6%, respectively. UC decreased graft survival (UC-group: 75.0% vs. noUC-group: 91.8%, p < 0.001), especially if associated with early UTI (UC-group: 71.4% vs. noUC-group: 77.8%, p < 0.001). At multivariate analysis, early UTI after KT (OR: 9.975, 95%-IC: 2.934–33.909, p < 0.001) and delayed graft function (DGF) (OR: 3.844, 95%-IC: 1.328–11.131, p: 0.013) were significant risk factors for UC, while ECD graft did not increase the risk of post-transplant UC. ECD grafts are not associated with UC. DGF and early UTI post-KT increase the risks of UC and reduce graft survival in the long-term. Therefore, aggressive management of early post-transplant UTI and strategies to reduce DGF incidence, such as machine preservation, are essential to prevent UC after KT.

Predictive Model of Ureteral Obstruction of Allograft Kidney Following Living Donor Kidney Transplantation

BACKGROUND

Ureteral obstruction is one of the most frequent urologic complications of kidney transplantation. This study aimed to analyze independent factors that contribute to ureteral obstruction following kidney transplantation and develop predictive models form those factors.

METHODS

As many as 545 kidney transplantations were analyzed. Patients underwent transplantation between January 2014 and December 2018. Logistic regression analysis was used to develop the predictive model. Both donor and recipient demographic characteristics and operative parameters were analyzed and presented.

RESULTS

There were 37 (6.8%) subjects who developed ureteral obstruction. The independent risk factors for ureteral obstruction were multiple allograft renal arteries, older donor ages (>38 years), and older recipient age (>60 years). From the receiver operating characteristic (ROC) curve analysis, the area under the ROC curve of the predictive model was 0.843 (P < .001). Subjects with >2 renal allograft arteries, recipient age >60 years, and donor age >38 years had 83.8% probability of developing ureteral stenosis after kidney transplantation.

CONCLUSION

Donor age, recipient age, and multiple renal arteries were independent risk factors of graft ureteral obstruction. Probability of developing ureteral obstruction should be considered pre-operatively in our population, using the proposed predictive model.

Urologic complications after transplantation of 225 en bloc kidneys from small pediatric donors ≤20 kg: Incidence, management, and impact on graft survival

Pediatric en bloc kidney transplants (EBKs) from small deceased pediatric donors are associated with increased early graft loss and morbidity. Yet, urologic complications post-EBK and their potential impact on graft survival have not been systematically studied. We retrospectively studied urological complications requiring intervention for 225 EBKs performed at our center January 2005 to September 2017 from donors ≤20 kg into recipients ≥18 years. Overall ureteral complication incidence after EBK was 9.8% (n = 22) (12% vs 2% for EBK donors < 10 vs ≥ 10 kg, respectively [P = .031]). The most common post-EBK urologic complication was a stricture (55%), followed by urine leak (41%). In all, 95% of all urologic complications occurred early within 5 months posttransplant (median, 138 days). Urologic complications could be successfully managed nonoperatively in 50% of all cases and had no impact on graft or patient survival. In summary, urologic complications after EBK were common, associated with lower donor weights, occurred early posttransplant, and were often amenable to nonoperative treatment, without adversely affecting survival. We conclude that the higher urologic complication rate after EBK (1) should not prevent increased utilization of small pediatric donor en bloc kidneys for properly selected recipients, and (2) warrants specific discussion with EBK recipients during the preoperative consent process.

Is peritoneal dialysis prior to kidney transplantation a risk factor for ureteral stenosis after adult to adult live kidney transplantation

Objectives

Major urinary complications such as urinary leaks, stenosis or urinary tract infections after kidney transplantation can lead to graft or patient loss. The effect of peritoneal dialysis on post-kidney transplantation complications have been discussed but its effect on ureteral stenosis is unknown. In this study, it was aimed to analyze factors effecting major ureteral complications after living donor kidney transplantation and impact of peritoneal dialysis and double J-stents (JJ stents).

Material and Methods

This study included 116 adult to adult living donor kidney transplant patients. Factors effecting major urologic complications after living donor kidney transplantation were analyzed. The donors were primary relatives of the recipients.

Results

Major urologic complications after living donor kidney transplantation was 8/116 (6.9%). Urinary leak was present in 2 (1.7%) patients. Ureteral stenosis was encountered in 6 (5.2%) patients. Double J stents were used in 84 (72.4%) of the cases. The effect of JJ ureteral stent was not statistically significant for urinary leak, ureteral stenosis (p= 0.074, p= 0.470, respectively). A total of 29 (25%) patients had peritoneal dialysis before kidney transplantation. Preoperative peritoneal dialyses and bacteriuria after kidney transplantation were independent risk factors for ureteral stenosis in multivariate analysis (p= 0.013, and p= 0.010 respectively).

Conclusion

In the guidance of the results of the present study, peritoneal dialysis prior to kidney transplantation and bacteriuria are independent risk factors for ureteral stenosis after living donor kidney transplantation. JJ stents have no effect on urologic complications after living donor kidney transplantation.

Results of Pediatric Kidney Transplants in an 8-Year Period: A Retrospective Study

BACKGROUND

Patient survival and quality of life is better after a kidney transplant compared with dialysis. In this retrospective study, we analyzed the results of pediatric kidney transplants in an 8-year period in our center.

METHODS

We reviewed the files of 166 children and adolescents who had undergone kidney transplants between 2008 and 2015 in our center. All the patients were younger than 18 years old and had been followed up for at least 2 years.

RESULTS

The transplanted kidneys were taken from live donors in 146 (88%) of the cases and from cadavers in 20 (12%) of the cases. They were procured from unrelated and related donors in 129 (90%) and 17 (10%) of the cases, respectively. Laparoscopic nephrectomy was done on 141 donors. The kidney vessels were anastomosed to the aorta, the common iliac, and the internal iliac in 3.6%, 56%, and 40.4% of cases, respectively. Preemptive kidney transplants were performed on 62 patients. The mean of patient survival was 124 ± 1.37 months. One- and five-year patient survival rates were 99% and 97%, respectively. The mean of graft survival was 118.29 ± 2.47 months. One- and five-year graft survival rates were 94% and 93%, respectively. Preemptive kidney transplants had a higher graft survival rate (P < .02).

CONCLUSION

Kidney transplant is a safe and feasible procedure in children and adolescents based on patient and graft survival outcomes. In our center, surgery complications led to kidney loss in very few cases.

An Update on Early Urological Complications in Kidney Transplantation: A National Cohort Study

<strong>BACKGROUND</strong> This study aimed to provide an update on the occurrence of early urological complications in living-donor and deceased-donor kidney transplantation (KTX). <strong>MATERIAL AND METHODS</strong> Data on all kidney transplant recipients in the Netherlands between January 2005 and December 2015 were retrieved from the prospectively collected Dutch National Organ Transplant Registry Database (NOTR). We assessed the incidence of major urological complications (MUCs) within 3 months after KTX, defined as urinary leakage and ureteral obstruction. Outcomes of living donor and deceased donor kidney transplants were compared. We performed regression analysis to identify predictive factors of urological complications and studied the influence of early urological complications on graft and patient survival. We performed an additional sub-study to explore the influence of preservation of the peri-ureteric connective tissue in living-donor KTX on the occurrence of urological complications. <strong>RESULTS</strong> Among 3329 kidney transplant recipients, urological complications occurred in 208 patients (6.2%) within 3 months after surgery. There were no significant differences in complication rates between recipients from living donors and deceased donors. Multiple regression analysis showed that older donor age and previous cardiac events of the recipient were predictors for the development of urological complications. Graft and patient survival were not affected by early MUCs. The additional sub-study showed that preservation of peri-ureteric tissue within living-donor KTX was not independently associated with urological complications. <strong>CONCLUSIONS</strong> Many living- and deceased-donor KTX recipients have early urological complications. MUCs did not affect long-term graft or patient survival.

Urologic complications in renal transplants

Urologic complications of renal transplant occur commonly and can have significant impact on graft function, survival, and patient morbidity. This review examines the prevalence of urologic complications, risk factors, diagnosis and options for management of the most common urologic complications.

Early urological complications after kidney transplantation: An overview

Urological complications, especially urine leaks, remain the most common type of surgical complication in the early post-transplant period. Despite major advances in the field of transplantation, a small minority of kidney transplants are still being lost due to urological problems. Many of these complications can be traced back to the time of retrieval and implantation. Serial ultrasound examination of the transplanted graft in the early post-operative period is of key importance for early detection. The prognosis is generally excellent if recognized and managed in a timely fashion. The purpose of this narrative review is to discuss the different presentations, compare various ureterovesical anastomosis techniques and provide a basic overview for the management of post-transplant urological complications.

Impact of ureteral stricture and treatment choice on long-term graft survival in kidney transplantation

We aimed to evaluate the influence of urological complications occurring within the first year after kidney transplantation on long-term patient and graft outcomes, and sought to examine the impact of the management approach of ureteral strictures on long-term graft function. We collected data on urological complications occurring within the first year posttransplant. Graft survivals, patient survival, and rejection rates were compared between recipients with and without urological complications. Male gender of the recipient, delayed graft function, and donor age were found to be significant risk factors for urological complications after kidney transplantation (P < .05). Death censored graft survival analysis showed that only ureteral strictures had a negative impact on long-term graft survival (P = .0009) compared to other complications. Death censored graft survival was significantly shorter in kidney recipients managed initially with minimally invasive approach when compared to the recipients with no stricture (P = .001). However, graft survival was not statistically different in patients managed initially with open surgery (P = .47). Ureteral strictures following kidney transplantation appear to be strongly negatively correlated with long-term graft survival. Our analysis suggests that kidney recipients with ureteral stricture should be managed initially with open surgery, with better long-term graft survival.

Peri- and Postsurgical Evaluations of Renal Transplant

Renal transplantation is the best treatment of choice for patient with chronic renal insufficiency because it provides better quality of life and longer survival. Survival rates for grafts and patients have improved over the recent decades because of significant evolution of surgical techniques and immunosuppressive treatment. However, renal transplantation is still associated with several complications, which may result in poor outcome. Cause of allograft dysfunction, which occurs in the early or late post-transplantation period, should be recognized immediately, so that it can be managed correctly. Surgical complications are rare and include renal artery stenosis, vascular thrombosis, hematoma, ureteral obstruction, urinary leak, hematoma, lymphocele, and perinephric fluid collections. Parenchymal complications, which are histopathologically categorized according to Banff classification, include antibody-mediated rejection, T-cell mediated rejection, interstitial fibrosis and tubular atrophy, calcineurin inhibitors, acute tubular injury, and others. Detection of changes in the allograft function is an important task in the appropriate management of complications. Although first-line imaging tool in the recognition of complications is ultrasonography, radionuclide imaging is a modality capable of assessing graft function qualitatively and quantitatively. Sequential renal scintigraphy is of particular importance in the differential diagnosis of complications, which need prompt and accurate management. Renal scintigraphy within 24-48 hours of transplantation surgery is recommended to serve as a baseline for comparison when functional impairment develops. In addition, studies have shown that early renal scintigraphy has a predictive value for the short-term and long-term graft outcomes. This article focuses in the main complications after renal transplantation, their imaging findings, and the role of renal scintigraphy.

Timing and Predictors of Early Urologic and Infectious Complications After Renal Transplant: An Analysis of a New York Statewide Database

OBJECTIVES

The most common complications after renal transplant are urologic and are a cause of significant morbidity in a vulnerable population. We sought to characterize the timing and predictors of urologic complications after renal transplant using a statewide database.

MATERIALS AND METHODS

We queried the New York Statewide Planning and Research Cooperative System database to identify patients who underwent renal transplant from 2005 to 2013. Postoperative complications included hydronephrosis, ureteral stricture, vesicoureteral reflux, nephrolithiasis, and urinary tract infections. Cox proportional hazards model was used to assess independent predictors of urologic complications.

RESULTS

In total, 9038 patients were included in the analyses. Urologic complications occurred in 11.3% of patients and included hydronephrosis (12.0%), nephrolithiasis (2.8%), ureteral stricture (2.4%), and vesicoureteral reflux (1.5%). We found that 23% experienced at least one urinary tract infection. On multivariate analysis, predictors of urologic complications included medicare insurance, hypertension, and prior urinary tract infection. Graft recipients from living donors were less likely to experience urologic complications than deceased-donor kidney recipients (P < .001).

CONCLUSIONS

Urologic complications occur in a significant proportion of renal transplants. Further study is needed to identify risk factors for complications after renal transplantation to decrease morbidity in this vulnerable population.

Outcomes of Kidney Transplant Recipients With Percutaneous Ureteral Interventions: A Single-Center Study

Background

Long-term outcomes of kidney transplantation recipients with percutaneous ureteral management of transplant ureteral complications are not well characterized.

Methods

Electronic records of 1753 recipients of kidney-alone transplant between January 2000 and December 2008 were reviewed. One hundred thirty-one patients were identified to have undergone percutaneous ureteral management, with placement of percutaneous nephrostomy tube or additional intervention (nephroureteral stenting and/or balloon dilation). Indications for intervention included transplant ureteral stricture or ureteral leak. Kaplan-Meier survival curves and multivariable regression modeling were performed to determine survival outcomes.

Results

Kaplan- Meier graft survival (P = 0.04) was lower in patients with percutaneous ureteral intervention for transplant ureteral complication. Graft survival at 1, 5, and 10 years was 94.3% 78.3%, and 59.1% for no intervention and 97.2%, 72.1%, and 36.2% for intervention cohort. Patient survival (P = 0.69) was similar between cohorts. Multivariate analysis demonstrated no association with graft failure (hazard ratio, 1.21; 95% confidence interval, 0.67-2.19; P = 0.53) or patient death (hazard ratio, 0.56; 95% confidence interval, 0.22-1.41; P = 0.22) in intervention group. The major cause of graft failure was infection for percutaneous ureteral intervention group (20.4%) and chronic rejection for those without intervention (17.3%).

Conclusions

Kidney transplant recipients with percutaneous ureteral interventions for ureteral complications do not have a significant difference in graft and patient survival outcomes. Therefore, aggressive nonoperative management can be confidently pursued in the appropriate clinical setting.

Imaging Complications of Renal Transplantation

Renal transplant complications are categorized as those related to the transplant vasculature, collecting system, perinephric space, renal parenchyma, and miscellaneous complications including posttransplant lymphoproliferative disorder. Many of these renal transplant complications are diagnosed with imaging. Medical complications including rejection, acute tubular necrosis, and drug toxicity also can impair renal function. These medical complications are typically indistinguishable at imaging, and biopsy may be performed to establish a diagnosis. Normal transplant anatomy, imaging techniques, and the appearances of renal transplant complications at ultrasound, computed tomography, and MR imaging are reviewed.