Late ureteral stenosis following renal transplantation: risk factors and impact on patient and graft survival

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.

Different profiles of acute graft pyelonephritis among kidney recipients from standard or elderly donors

Background

Acute graft pyelonephritis (AGPN) is a relatively common complication in kidney transplants (KTs); however, the effects on allograft function, diagnostic criteria, and risk factors are not well established.

Methods

Retrospective analysis of all consecutive adult KTs was performed between 01 January 2011 and 31 December 2018 (follow-up ended on 31 December 2019) to examine the association between the diagnosis of AGPN (confirmed with magnetic resonance imaging [MRI]) during the first post-transplantation year and graft outcomes.

Results

Among the 939 consecutive KTs (≈50% with donors ≥60 years), we identified 130 MRI-confirmed AGPN episodes, with a documented association with recurrent and multidrug-resistant bacterial urinary tract infections (UTIs) (p < 0.005). Ureteral stenosis was the only risk factor associated with AGPN (OR 2.9 [95% CI, 1.6 to 5.2]). KTs with AGPN had a decreased allograft function at the first year (ΔeGFR 6 mL/min/1.73 m2 [-2-15] in non-AGPN vs. -0.2 [-6.5-8.5] in AGPN, p < 0.001), with similar and negative profiles in KTs from standard or elderly donors. However, only KTs with AGPN and a donor <60 years showed reduced death-censored graft survival (p = 0.015); most of this subgroup received anti-thymocyte globulin (ATG) induction (40.4% vs. 17.7%), and their MRI presented either a multifocal AGPN pattern (73.9% vs. 56.7%) or abscedation (28.3% vs. 11.7%). No difference was noted in death-censored graft survival between early (<3 months post-KT) or late (3-12 months) AGPN, solitary/recurrent forms, or types of multidrug-resistant pathogens. Linear regression confirmed the independent role of multifocal pattern, abscedation, ATG induction, and donor age on the eGFR at the first year.

Conclusion

AGPN, influenced by multifocal presentation, ATG induction, donor age, and abscedation, affects kidney function and significantly impacts allograft survival in KTs with donors <60 years.

Single-port robotic-assisted ureteral reconstruction for management of strictures after renal transplantation

Ureteral strictures are a common and often challenging complication of renal transplantation. The use of single-port (SP) robotic-assisted laparoscopic surgery is a novel approach in the management of these patients. Here we describe 3 patients with stricture of the transplant ureter causing hydronephrosis and allograft dysfunction, whose ureteral reconstructions were successfully performed using the SP robotic-assisted laparoscopic approach. Two patients underwent transplant-to-native ureteroureterostomy and 1 patient underwent ureteroneocystostomy. We demonstrate that the use of concurrent ureteroscopy and near-infrared fluorescence enables safe and rapid identification of native and transplant ureters. In addition, side-to-side anastomosis of transplant-to-native ureters allows for preservation of ureteral vasculature. In this limited series, the SP robotic platform demonstrates great promise in simplifying and streamlining our approach to ureteral strictures in this patient population.

Robotic ureter reconstruction using the native ureter to treat long-segment ureteral stricture of the transplant kidney utilizing Indocyanine green: The first Korean experience

PURPOSE

Ureteral strictures are a common complication after kidney transplantation. Open reconstruction is preferred for long-segment ureteral strictures that cannot be resolved endoscopically; however, it is known to have the potential to fail. We report 2 successful cases of robotic reconstruction surgery of a transplant ureter using the native ureter with the aid of intraoperative Indocyanine green (ICG).

MATERIALS AND METHODS

Patients were placed in semi-lateral position. Using Da Vinci Xi, the transplant ureter was dissected, and the stricture site was identified. End-to-side anastomosis of the native ureter to the transplant ureter was performed. ICG was utilized to identify the course of the transplant ureter and confirm the vascularity of the native ureter.

RESULTS

Case 1: A 55-year-old female underwent renal transplantation at another hospital. She had recurrent febrile urinary tract infections (UTIs) and a ureteral stricture requiring percutaneous nephrostomy (PCN). The PCN and ureteral stent were removed successfully after surgery. The patient had only 1 febrile UTI episode after surgery. Case 2: A 56-year-old female underwent renal transplantation at another hospital. She had acute pyelonephritis 1-month post-transplantation, and a long-segment ureteral stricture was identified. She developed a UTI with anastomosis site leakage in the early postoperative period, which resolved with conservative treatment. The PCN and ureteral stent were removed 6 weeks after surgery.

CONCLUSIONS

Robotic surgery for managing long-segment ureteral stricture after kidney transplantation is safe and feasible. The use of ICG during surgery to identify the ureter course and its viability can improve the success.

Contemporary risk factors for ureteral stricture following renal transplantation

INTRODUCTION

Allograft ureteral strictures after renal transplantation impact graft function and increase patient morbidity. They can be challenging to treat and may require complex surgical repair. Therefore, the objective of this study was to identify contemporary risk factors for the development of post-renal transplant ureteral strictures.

METHODS

A retrospective analysis was performed on all renal transplant patients at Vancouver General Hospital from 2008-2019. Demographics, clinical parameters, and outcomes were compared between patients who did and did not develop ureteral strictures. Putative risk factors for ureteral stricture were analyzed using logistic regression.

RESULTS

A total of 1167 patients were included with a mean followup of 61.9±40.8 months. Ureteral strictures occurred in 25 patients (2.1%). Stricture patients had no demographic differences compared to non-stricture patients but had significantly higher rates of postoperative complications, longer hospital stays, and decreased renal function one year post-transplant (all p<0.05). On multivariable analysis, cold ischemia time >435 minutes (odds ratio [OR] 43.9, confidence interval [CI] 1.6-1238.8, p=0.027), acute rejection (OR 3.0, CI 1.1-7.4, p=0.027), and postoperative complications (OR 112.4, CI 2.4-5332.6, p=0.016) were risk factors for stricture.

CONCLUSIONS

Renal transplant patients with ureteral stricture experience greater morbidity and reduced post-transplant renal function compared to non-stricture patients. Our findings support attempts to reduce cold ischemia time, acute rejection, and postoperative complications to mitigate this potential complication. Our study is limited by the low incidence of ureteral stricture resulting in a small sample of stricture patients. Future research in a larger, multicenter setting is warranted.

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.

Renal Transplant Hydroureteronephrosis as a Manifestation of Rejection: An Under-Recognized Entity?

Hydroureteronephrosis (HUN) of the renal transplant (RT) can be obstructive or non-obstructive, refluxing or non-refluxing, and can cause allograft dysfunction. HUN of the RT as a manifestation of rejection is uncommon and has not been described in children. We describe two pediatric RT recipients who presented with late-onset HUN, 5 and 10 years after transplantation. Both had new-onset HUN which occurred at the time of rejection; HUN resolved in both patients after treatment of rejection. Renal function stabilized in both patients without the need for stent or nephrostomy tube placement. There was no obstruction or vesicoureteral reflux (VUR). Edema of the uroepithelial cells leading to transient obstruction causing HUN is a most likely explanation. We conclude that treatment of rejection in patients without obstruction or VUR may lead to resolution of HUN without the need for urological interventions.

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.

Temporary Covered Metallic Ureteral Stent Placement for Ureteral Strictures following Kidney Transplantation: Experience in 8 Patients

This brief report presents 8 patients with silicone-covered metallic stent placement for ureteral strictures refractory to double-J stent placement, following kidney transplantation. Stent removal was successfully performed in 7 patients via antegrade (n = 4) or retrograde (n = 3) access 6 weeks to 6 months after stenting for elective removal (6-month interval, n = 3), urothelial hyperplasia (n = 2), or stent migration (n = 2), and their mean primary ureteral patency after stent removal was 15.4 months (range, 2-27 months). Hematuria (n = 2) and pain (n = 3) occurred, but resolved within 1 week. One stent was removed during reconstructive surgery. During follow-up of mean 22.6 months after stent removal, ureteral strictures recurred in 2 patients.

Role for contrast-enhanced ultrasound in assessing complications after kidney transplant

Kidney transplantation (KT) is an effective treatment for end-stage renal disease. Despite their rate has reduced over time, post-transplant complications still represent a major clinical problem because of the associated risk of graft failure and loss. Thus, post-KT complications should be diagnosed and treated promptly. Imaging plays a pivotal role in this setting. Grayscale ultrasound (US) with color Doppler analysis is the first-line imaging modality for assessing complications, although many findings lack specificity. When performed by experienced operators, contrast-enhanced US (CEUS) has been advocated as a safe and fast tool to improve the accuracy of US. Also, when performing CEUS there is potentially no need for further imaging, such as contrast-enhanced computed tomography or magnetic resonance imaging, which are often contraindicated in recipients with impaired renal function. This technique is also portable to patients' bedside, thus having the potential of maximizing the cost-effectiveness of the whole diagnostic process. Finally, the use of blood-pool contrast agents allows translating information on graft microvasculature into time-intensity curves, and in turn quantitative perfusion indexes. Quantitative analysis is under evaluation as a tool to diagnose rejection or other causes of graft dysfunction. In this paper, we review and illustrate the indications to CEUS in the post-KT setting, as well as the main CEUS findings that can help establishing the diagnosis and planning the most adequate treatment.

Robotic Surgery for the Reconstruction of Transplant Ureteral Strictures

OBJECTIVE

To demonstrate the feasibility and success of a robotic approach to reconstruction of ureterovesical anastomotic strictures in kidney transplants.

MATERIALS AND METHODS

Between November 2017 and December 2019, a total of 5 patients with transplant ureteral stricture were identified and treated with robot assisted laparoscopic repair. All patients were confirmed to have ureteral stricture with a preoperative antegrade nephrostogram through their nephrostomy tube and cystogram. The patients demographics, ureteral characteristics, type of procedure, and outcomes are reported.

RESULTS

All patients were diagnosed after evaluation for renal deterioration. The average age of the patients was 49 years old. The average stricture length was 2.5 cm, and the location was variable, though more commonly in the distal ureter. Three patients required a pyelo-vesicostomy, while 2 required a ureteroneocystostomy. The mean length of stay was 2.2 days. Average follow-up was 97 days, with all 5 patients having successful outcomes, no strictures or delayed leaks were identified. There were no wound infections or readmissions within 30 days.

CONCLUSION

Though a complex repair, the robot-assisted approach to transplant ureter reconstruction using either an end to side neoureterocystotomy or direct pyelo-vesicotomy is technically feasible and successful. Given the many advantages inherent in comparison to an open approach, the robotic repair offers significant advantages to both the patient and the surgeon who is experienced with robotic surgery and reconstructive principles.

Imaging of Renal Transplant Complications throughout the Life of the Allograft: Comprehensive Multimodality Review

The kidney is the most commonly transplanted solid organ. Advances in surgical techniques, immunosuppression regimens, surveillance imaging, and histopathologic diagnosis of rejection have allowed prolonged graft survival times. However, the demand for kidneys continues to outgrow the available supply, and there are efforts to increase use of donor kidneys with moderate- or high-risk profiles. This highlights the importance of evaluating the renal transplant patient in the context of both donor and recipient risk factors. Radiologists play an integral role within the multidisciplinary team in care of the transplant patient at every stage of the transplant process. In the immediate postoperative period, duplex US is the modality of choice for evaluating the renal allograft. It is useful for establishing a baseline examination for comparison at future surveillance imaging. In the setting of allograft dysfunction, advanced imaging techniques including MRI or contrast-enhanced US may be useful for providing a more specific diagnosis and excluding nonrejection causes of renal dysfunction. When a pathologic diagnosis is deemed necessary to guide therapy, US-guided biopsy is a relatively low-risk, safe procedure. The range of complications of renal transplantation can be organized temporally in relation to the time since surgery and/or according to disease categories, including immunologic (rejection), surgical or iatrogenic, vascular, urinary, infectious, and neoplastic complications. The unique heterotopic location of the renal allograft in the iliac fossa predisposes it to a specific set of complications. As imaging features of infection or malignancy may be nonspecific, awareness of the patient's risk profile and time since transplantation can be used to assign the probability of a certain diagnosis and thus guide more specific diagnostic workup. It is critical to understand variations in vascular anatomy, surgical technique, and independent donor and recipient risk factors to make an accurate diagnosis and initiate appropriate treatment.^©RSNA, 2019.

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.

[Indocyanine green fluorescence to visualize the ureteric vascularization of kidney transplants: An exploratory study]

INTRODUCTION

Urinary complications after kidney transplantation are common and can compromise renal function. While they are mainly attributed to ischemic lesions of the ureter, there is no existing method to evaluate its vascularization during surgery. The aim of the study was to evaluate if indocyanine green, revealed by infra-red light andused to visualize tissue perfusion, could provide an appreciation of the ureter's vascularization during kidney transplantation.

METHODS

This feasibility study was conducted over one month, on eleven consecutive kidney transplants. During transplantation, an injection of indocyanine green enabled the surgeon to visualize in real time with an infra-red camera the ureter fluorescence. Its intensity was reported on a qualitative and semi-quantitative scale. Occurrence of urinary complications such as stenosis or ureteral fistula were collected during 6 months.

RESULTS

In all of the 11 cases (100%), the last centimeters of the ureters were not fluorescent. Three (27%) ureters were poorly or partiallly fluorescent. Out of these three cases, only one case of urinary fistula occurred, followed by ureteric stenosis. In the series, two fistulas (18%) and two ureteric stenoses (18%) occurred. No side effects were observed. The low number of events did not allow statistical analysis.

CONCLUSION

Infra-red fluorescence of indocyanine green could be a simple and innovative way to appreciate the transplant's ureteric vascularization during kidney transplantation. It could help surgeons to identify the level of ureter section and to decide the anastomosis technique, in order to limit urinary complications.

LEVEL OF EVIDENCE

3.

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.

Development of Ureteral Stenosis/Obstruction in Kidney Transplant

This retrospective study describes the incidence and prevalence of ureteral stenosis/obstruction (US/O) in a cohort of 334 renal transplants recipients in our center over the last 5 years and evaluates the risk factors that may influence the occurrence of US/O. The parameters studied included the following: history of prostate disease, smoking, urinary tract infection, renal lithiasis, ureterovesical reflux, presence and level of polar artery, type of ureterovesical anastomosis, delayed graft function, double J catheter, lymphocele, urinoma, acute rejection, prolonged catheterization, post-transplant infravesical obstruction and BK virus infection, age of the donor and recipient, and months on dialysis. Also evaluated were the nadir creatinine and instances of cold ischemia, asystole, reanastomosis, and double J catheter removal. The average incidence of US/O was 7.6% and was significantly correlated with factors of alteration of the uretero-bladder dynamics without finding a relation to vascular factors.

Relationship between early proteinuria and long term outcome of kidney transplanted patients from different decades of donor age

Background

Proteinuria after kidney transplantation portends a worse graft survival. However the magnitude of proteinuria related to patient and graft survival and its correlation with donor and recipient characteristics are poorly explored.

Methods

This study investigated the impact of post transplant proteinuria in the first year in 1127 kidney transplants analyzing the impact of different donor ages. Proteinuria cut off was set at 0.5 g/day.

Results

Transplants with proteinuria > 0.5 g/day correlated with poor graft and patient outcome in all donor age groups. In addition, 6-month-1-year proteinuria increase was significantly associated with graft outcome, especially with donors > 60 years old (p <  0.05; Odd Ratio 1.8). 1-year graft function (eGFR < or ≥ 44 ml/min) had similar impact to proteinuria (≥ 0.5 g/day) on graft failure (Hazard Ratio 2.77 vs Hazard Ratio 2.46). Low-grade proteinuria (0.2–0.5 g/day) demonstrated a trend for worse graft survival with increasing donor age. Also in kidney-paired analysis proteinuria ≥0.5 effect was more significant with donors > 50 years old (Odd Ratio 2.3).

Conclusions

Post-transplant proteinuria was increasingly harmful with older donor age. Proteinuria ≥0.5 g/day correlates with worse outcomes in all transplanted patients. Prognostic value of proteinuria and eGFR for graft and patient survival was comparable and these two variables remain significant risk factors even in a multivariate model that take into consideration the most important clinical variables (donor age, rejection, delayed graft function and cytomegalovirus viremia among others).

[Results of surgical revisions for ureteral complications after renal transplantation]

OBJECTIVE

To analyze the results of surgical revision for ureteral complication (ureteric stenosis or urinary leakage) after renal transplantation over a period of 10 years.

MATERIALS AND METHODS

We performed a retrospective study on 1313 consecutive kidney transplantations carried out in a University Hospital Center between 2005 and 2014. The data of the patients who developed a ureteral stenosis or a urinary leakage secondary to a renal transplantation were analyzed. Combined organ transplantations (kidney-liver and kidney-pancreas), as well as pediatric transplantations were excluded.

RESULTS

Seventy-six patients (5.8%) had ureteric stenosis or urinary leakage after renal transplantation. Forty-six patients (3.5%) underwent surgical revision: 27 for ureteral stenosis, 19 for urinary leakage. Early success was achieved in 26 patients (56.5%), including 14 ureteric stenosis (51.9%) and 12 urinary leakage (63.2%) (P=0.45). After a complementary endoscopic or surgical treatment, the final success rate was increased to 73.1% (34 patients): 20 ureteric stenosis (74.1%) and 14 urinary leakage (73.7%) (P=0.98). There were 2 graft losses (4.3%) and one death (2.2%). The mean glomerular filtration rate estimated by the MDRD was 44.58mL/min/1.73m² (±14.7) before surgery and 45.37mL/min/1.73m² (±16.5) 6 months after surgery (P=0.92).

CONCLUSION

Although frequently challenging, surgical revisions for ureteral complications after renal transplantation give good results, with a low rate of graft loss and mortality.

LEVEL OF EVIDENCE

4.

Is delayed graft function associated with ureteral stenosis in the kidney transplant recipient? A case-control study

INTRODUCTION

Ureteral stricture (US) in the kidney transplant recipient is a rare complication that can lead to morbidity and graft loss. Risk factor recognition is crucial in the prevention and management of this entity. Delayed graft function (DGF), as defined by the need for dialysis in the first week after transplantation, has been proposed as a risk factor in previous studies. Our objective is to determine the impact of DGF in US development in kidney transplant patients.

METHODS

We designed a matched case-control study. US cases in kidney transplant recipients were identified in the 2008-2017 period. We defined US as the rise in serum creatinine associated with findings suggesting obstruction in ultrasound, scintigraphy, or retrograde pyelogram; any other cause of graft dysfunction was excluded. Controls were defined as kidney transplant recipients from the same population and period without US, matched in a 1:2 fashion by age, sex, and donor type.

RESULTS

From 532 kidney transplant patients, 31 cases and 62 controls were included. Cumulative US incidence was 58 per 1000 cases. When calculating for odds ratio (OR), post-operative urinoma (OR 3.2; 95% confidence interval [CI] 2.36-4.37) and ureteral duplication (OR 3.29; 95% CI 2.40-4.51) were associated with an increased risk for US, while DGF was not found to be statistically significant as a risk factor (OR 3.3; 95% CI 0.96-11.52). No statistically significant differences were found between groups in other pre- and post-transplant-related factors CONCLUSIONS:: DGF was not associated with US in our cohort; however, ureteral duplication and postoperative urinoma were associated with an increased risk of graft ureteral stenosis development.

Native kidney cytomegalovirus nephritis and cytomegalovirus prostatitis in a kidney transplant recipient

We present a case of cytomegalovirus (CMV) native kidney nephritis and prostatitis in a CMV D+/R- kidney transplant recipient who had completed six months of CMV prophylaxis four weeks prior to the diagnosis of genitourinary CMV disease. The patient had a history of benign prostatic hypertrophy and urinary retention that required self-catheterization to relieve high post-voiding residual volumes. At 7 months post-transplant, he was found to have a urinary tract infection, moderate hydronephrosis of the transplanted kidney, and severe hydroureteronephrosis of the native left kidney and ureter, and underwent native left nephrectomy and transurethral resection of the prostate. Histopathologic examination of kidney and prostate tissue revealed CMV inclusions consistent with invasive CMV disease. This case highlights that CMV may extend beyond the kidney allograft to involve other parts of the genitourinary tract, including the native kidneys and prostate. Furthermore, we highlight the tissue-specific risk factors that preceded CMV tissue invasion. In addition to concurrent diagnoses, health care providers should have a low threshold for considering late-onset CMV disease in high-risk solid organ transplant recipients presenting with signs and symptoms of genitourinary tract pathology.

Self-Expandable Covered Metallic Stent (UVENTA) to Treat a Ureteral Stricture After Renal Transplant: A Case Report

We present the use of a self-expandable covered metallic stent (UVENTA; TaeWoong Medical, Gyeonggi-do, South Korea) to treat a ureteral stricture after kidney transplant. In this report, we describe the procedure and short-term outcomes of a patient with a recurrent distal stricture who did not respond to percutaneous balloon dilation. We decided to place this temporary stent as an alternative to complex surgery. The aim of the procedure was to get a chronic dilation of the stricture up to 7 mm to stabilize the fibrotic tissue. The procedure was easily and quickly performed by an antegrade and retrograde combined approach. The postoperative course was uneventful. The stent was left in situ for 7 months. No complications were noted, and the renal function remained stable. The stent was easily removed, and 5 months later there were no signs of recurrence. The UVENTA device was shown to be an easy, safe, and effective minimally invasive treatment for ureteral stricture in renal transplant. Proper permanence time and long-term results need to be explored.

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.

Initial Experience in the Use of Novel Auto-expandable Metal Ureteral Stent in the Treatment of Ureter Stenosis in Kidney Transplanted Patients

INTRODUCTION

Ureter stenosis in renal transplantation patients is a relatively frequent complication that negatively conditions graft evolution. The use of ureteral stents is a valid treatment alternative to the use of double-J catheters in patients for whom surgery is not contemplated or after surgical recurrence. We present our initial experience with five patients treated using this technique.

MATERIALS AND METHODS

We describe a total of five patients with ureteral stenosis after renal transplantation who were treated using ureteral stent model UVENTA (Taewoong Medical, Seoul, Korea) in our center. The median follow-up was 18 months (range, 4 to 38 months). We describe the clinical history of patients and previous treatments on ureteral stenosis. The technical procedure of placement is described. The clinical course is analyzed by measurement of renal function and imaging tests, as well as post-stent complications. Survival of the renal graft is evaluated.

RESULTS

The procedure could be completed in all patients without complications. The technique was effective in all patients, with correction of creatinine value and hydronephrosis during the renal ultrasound test. One patient suffered a urinary tract infection episode associated with the use of the ureteral stent. One patient suffered the loss of the renal graft secondary to the development of cryoglobulins. One hundred percent of the ureteral stents are functioning as of the writing of this article.

CONCLUSIONS

In renal transplantation patients with ureter stenosis, metallic stents are a useful technique with low morbidity and associated complications.

Preperitoneal Surgical Approach to Treat Vesicoureteral Anastomotic Leakage, Distal Stenosis or Reflux After Kidney Transplantation

BACKGROUND

If endourological approaches are not applicable to treat vesicoureteral anastomotic complications after kidney transplantation, the surgical gold standard in many transplant centers is pyeloureterostomy or ureteroureterostomy using the native ureter. We report an original preperitoneal technique that can be used for vesicoureteral reanastomosis in kidney transplant recipients not eligible for endourological treatment.

METHODS

Between January 2011 and December 2015, 18 kidney transplant recipients underwent this new surgical procedure. Of this number, 15 subjects with at least 1 year of follow-up were included in the analysis. The indications were vesicoureteral reflux, anastomotic stenosis, and leakage in 8, 5, and 2 patients, respectively. Briefly, a double J stent was preoperatively inserted into the grafted ureter. Surgery was performed through a Pfannenstiel incision. The preperitoneal space surrounding the bladder was dissected and the distal part of the grafted ureter was identified and mobilized. The anastomotic area was resected and another vesicoureteral anastomosis was performed (Lich-Gregoir technique), keeping the JJ stent in place for three weeks.

RESULTS

This procedure was performed 213 days (range 17-2608) after kidney transplantation. Median surgical duration was 179 minutes (range 112-314) and median hospital stay 8 days (range 4-14). The success rate was 86.7% (13/15), with a median follow-up of 1148 days (range 517-1808). In two patients, symptomatic recurrence of vesicoureteral reflux required a pyeloureterostomy using the native ureter.

CONCLUSIONS

The authors describe a simple technique that avoids transperitoneal dissection, potentially yielding more esthetic results thanks to easy access, as well as excellent outcomes.

Ureteral Stenosis After Renal Transplantation-A Single-Center 10-Year Experience

BACKGROUND

Kidney transplantation (KT) is the definitive treatment for ESRD. Ureteral stenosis (US) is one of the most common urologic complications and has been reported in 2.6%-15% of KTs.

METHODS

We reviewed data for 973 consecutive KT procedures performed at our center from January 2004 to September 2014, with evaluation of US management and recurrence rate.

RESULTS

The 973 KTs were performed with the use of the direct ureterovesical (UV) implantation Paquin technique, and the mean follow-up time was 44.3 ± 30.2 [range, 3-111] months. During this period, 33 cases of US (3.39%) were reported. The interval from KT to US diagnosis was 10.6 ± 23.0 (range, 0.5-98.0) months. The majority of the US cases were located in the distal ureter and UV junction (83.9%), with only 2 cases of middle ureter stenosis and 2 cases of ureteropelvic junction. Mean US length was 2.5 ± 1.9 (range, 1.0-10.0) cm. Surgical management and global and treatment-specific recurrence rates were reviewed. Primary surgical treatment recurrence rate was higher for the endoscopic approach, with a mean global time from treatment to US recurrence of 6.9 ± 16.3 (range, 0-65) months and a median of 2.0 months. Open surgical approach was the main recurrence treatment option (74%). There were 2 cases of graft loss. Success rate evaluation of overall and treatment-specific primary surgical management did not reveal significant differences (P > .05) according to stenosis length (<1.5, 1.5-3.0, or >3.0 cm), time between transplant and stenosis (≤3, 3-12, or >12 mo), or stenosis location (distal, middle, or upper ureter). However, there was clearly a trend to higher success rate in smaller stenosis (<1.5 cm) and early management (≤3 mo), particularly with the use of balloon dilation.

CONCLUSIONS

US management should be decided on a case-by-case basis according to clinical characteristics, treatment-specific recurrence rate, and previous surgical options.

First Case Report of Acute Renal Failure After Mesh-Plug Inguinal Hernia Repair in a Kidney Transplant Recipient

Acute renal failure due to ureter compression after a mesh-plug inguinal repair in a kidney transplant recipient has not been previously reported to our knowledge. A 62-year-old man, who successfully underwent kidney transplantation from a deceased donor 6 years earlier, was admitted for elective repair of a direct inguinal hernia. The patient underwent an open mesh-plug repair of the inguinal hernia with placement of a plug in the preperitoneal space. We did not observe the transplanted ureter and bladder during dissection of the inguinal canal. Immediately after surgery, the patient became anuric, and a graft sonography demonstrated massive hydronephrosis. The serum creatinine level increased rapidly, and the patient underwent an emergency reoperation 8 hours later. During surgery, we did not identify the ureter but, immediately after plug removal, urine output increased progressively. We completed the hernia repair using the standard technique, without plug interposition, and the postoperative course was uneventful with complete resolution of graft dysfunction 3 days later. Furthermore, we reviewed the clinical features of complications related to inguinal hernia surgery. An increased risk of urological complications was reported recently in patients with a previous prosthetic hernia repair undergoing kidney transplantation, mainly due to the mesh adhesion to surrounding structures, making the extraperitoneal dissection during the transplant surgery very challenging. Moreover, older male kidney transplant recipients undergoing an inguinal hernia repair may be at higher risk of graft dysfunction due to inguinal herniation of a transplanted ureter. Mesh-plug inguinal hernia repair is a safe surgical technique, but this unique case suggests that kidney transplant recipients with inguinal hernia may be at higher risk of serious urological complications. Surgeons must be aware of the graft and ureter position before proceeding with hernia repair. A prompt diagnosis with graft sonography and abdominal computed tomography scan and emergency surgery may avoid the need for nephrostomy and may resolve graft dysfunction more rapidly.

A Preliminary Study Into the Significance of Intrarenal Reflux in BK Virus Nephropathy After Kidney Transplantation

Background

The BK virus typically colonizes the lower urinary tract and is the causative agent in BK virus nephropathy (BKVN), which can progress to allograft dysfunction and graft loss. Urinary reflux in kidney allografts is induced by vesicoureteral reflux or disturbances in intrarenal reflux (IRR), believed to be associated with BKVN. This study was designed to elucidate the relationship between BKVN and IRR.

Methods

We examined 30 renal transplant recipients histologically diagnosed with BKVN using anti-Simian virus 40 immunohistochemistry and 60 clinically matched control recipients. The BKVN patients were divided into stable (n = 12) and progressive (n = 18) groups according to allograft kidney function 1 year after diagnosis. Histological rejection scores according to the pathological classification of rejection in renal allografts (Banff classification), histological BKVN stages, and histological polyomavirus load levels (pvl) proposed by the Banff working group were evaluated. The IRR was quantified by histological reflux scores defined with retention and reflux of immunostained Tamm-Horsfall protein in renal tubules and glomeruli.

Results

Higher reflux scores were observed in the BKVN group compared with that in the control group. No differences in clinical parameters were observed between the BKVN and control groups. Reflux scores and pvl were significantly higher in the progressive group than in the stable BKVN group with no significant difference in BK stage observed between groups. Reflux scores were found to be significantly correlated with pvl.

Conclusions

Our preliminary study suggested that IRR might be a predisposing and prognostic factor in BKVN.

Urological Consequences following Renal Transplantation: A Review of the Literature

Renal transplant (RT) represents the treatment of choice for end-stage renal disease (ESRD) but harbours a wide range of possible complications and therapeutic challenges of urological competence. Dialysis years and clinical medical background of these patients are risk factors for sexual dysfunction and lower urinary tract symptoms (LUTS). On the contrary, RT itself may have a number of possible surgical complications such as ureteral stenosis and urinary leakage, while immunosuppressive treatment is a known risk factor for de-novo malignancies.

The present review describes the main urologic problems of RT patients and their up-to-date treatment options according to the most recently available literature evidences.

Ureteric reconstruction for the management of transplant ureteric stricture: a decade of experience from a single centre

This study was conducted to review the outcomes of patients who had undergone surgical repair of a ureteric stricture following renal transplantation. All patients who developed a ureteric stricture and underwent ureteric reconstruction following renal transplantation, between December 2003 and November 2013, were reviewed. One thousand five hundred and sixty renal transplants were performed during the study period. Forty patients required surgical repair of a ureteric stricture (2.5%, 25 male, median age 48 [14-78]). The median time to stricture was 3 [1-149] months. 19 patients were reconstructed by reimplantation to the bladder, 18 utilized a Boari flap, two were a pre-existing ileal conduit and one was an anastomosis to a native ureter. In one patient, reconstruction was impossible and consequently an extra-anatomic stent was used. Two patients required re-operation for restricture and kinking. Median serum creatinine at 12 months following surgery was 148 [84-508] μmol/l. There was no 90-day mortality. Eleven grafts were lost at the time of this study, a median time of 11 [1-103] months after reconstruction. The incidence of ureteric stricture following renal transplant is low. Surgical reconstruction of the transplant ureter is the optimal treatment and is successful in the majority of patients.

Surgical complications following 1670 consecutive adult renal transplantations: A single center study

BACKGROUND AND AIMS

The aim of the study was to clarify the frequency and the sequel of surgical complications occurring within 1 year after renal transplantation.

PATIENTS AND METHODS

Surgical complications after 1670 consecutive adult kidney transplantations performed between 2000 and 2009 were retrospectively analyzed. In 2%, a living-related allograft was used, and 10% were retransplantations. An intravesical technique without stenting was used for the ureteric implantation.

RESULTS

There were 282 surgical complications occurring in 259 (15.5%) transplantations. Ureteral obstruction occurred in 53 (3.1%), lymphoceles in 39 (1.5%), postoperative hemorrhage in 36 (2.1%), and renal vein thrombosis in 22 (1.3%) patients, respectively. Out of the 17 lung emboli, 4 were fatal. Male recipients had twice as much ureteral stenosis as female (2.4 vs 1.2%, p < 0.05), and the opposite was true of urinary leakage (1.8% vs 4.0%, p < 0.025). Five-year patient and graft survival was impaired in patients with complications compared with patients without complications. Five-year patient survival was 92% versus 88% and graft survival 87% versus 74%.

CONCLUSION

Surgical complications impair patient and graft survival after kidney transplantation.

Surgical management of early and late ureteral complications after renal transplantation: techniques and outcomes

BACKGROUND

In this study, we present our experience with ureteral complications requiring revision surgery after renal transplantation and compare our results to a matched control population.

METHODS

We performed a retrospective analysis of our database between 1997 and 2012. We divided the cases into early (<60 d) and late repairs. Kaplan-Meier and Cox proportional hazards models were used to compare graft survival between the intervention cohort and controls generated from the Scientific Registry of Transplant Recipients data set.

RESULTS

Of 2671 kidney transplantations, 51 patients were identified as to having undergone 53 ureteral revision procedures; 43.4% of cases were performed within 60 d of the transplant and were all associated with urinary leaks, and 49% demonstrated ureteral stenosis. Reflux allograft pyelonephritis and ureterolithiasis were each the indication for intervention in 3.8%; 15.1% of the lesions were located at the anastomotic site, 37.7% in the distal segment, 7.5% in the middle segment, 5.7% proximal ureter, and 15.1% had a long segmental stenosis. In 18.9%, the location was not specified. Techniques used included ureterocystostomy (30.2%), ureteroureterostomy (34%), ureteropyelostomy (30.1%), pyeloileostomy (1.9%), and ureteroileostomy (3.8%). No difference in overall graft survival (HR 1.24 95% CI 0.33-4.64, p = 0.7) was detected when compared to the matched control group.

CONCLUSION

Using a variety of techniques designed to re-establish effective urinary flow, we have been able to salvage a high percentage of these allografts. When performed by an experienced team, a ureteric complication does not significantly impact graft survival or function as compared to a matched control group.

An update on ABO-incompatible kidney transplantation

ABO-incompatible kidney transplantation is nowadays a well-established procedure to expand living donor transplantation to blood group incompatible donor/recipient constellations. In the last two decades, transplantation protocols evolved to more specific isohaemagglutinin elimination techniques and established competent antirejection protection protocols without the need of splenectomy. ABOi kidney transplantation associated accommodation despite isohaemagglutinin reappearance, C4d positivity of peritubular capillaries as well as the increased incidence of bleeding complications is currently under intense investigation. However, most recent data show excellent graft survival rates equivalent to ABO-compatible kidney transplantation outcome.

Ureteral obstruction following renal transplantation: causes, diagnosis and management

Renal transplantation, first performed successfully in the 1950s, is the treatment of choice for most patients with end-stage renal failure. It confers longer term survival and a better quality of life than do both haemodialysis and peritoneal dialysis. The success of renal transplantation is dependent on the preservation of renal graft function and despite the many advances in surgical techniques, immunosuppressive regimens and supportive therapies, many challenges remain including post-operative ureteral obstruction. This complication can pose a risk to graft, and, occasionally, to patient survival. In this pictorial review, we describe the causes of ureteral obstruction following renal transplantation and illustrate the pivotal role of radiology in both diagnosing and managing these complications.

Native ureteropyelostomy in the treatment of obstructive uropathy in adult renal transplant. Experience and technical alternatives

OBJECTIVE

To analyze and evaluate our experience in surgical treatment with the open approach of the complex ureteral stenosis after adult kidney transplantation in a tertiary level hospital in the last seven years. We have reviewed the different surgical options used.

PATIENTS AND METHODS

A total of 589 consecutive adult renal transplants were performed from January 2005 to December 2012. Of these, 1.1% showed some degree of symptomatic obstructive uropathy which after initial urinary diversion required open surgical approach using the ipsilateral or contralateral native urinary tract. Characteristics of the patient, clinical examinations performed and surgical technique performed as well as their results are presented.

RESULTS

During the period under review, in 5 men and 2 women who had ureteral stenoses after renal transplant, 7 reparative surgeries were performed by open ureteropyelostomy, using ipsilateral native ureter in 6 cases and contralateral ureter in the remaining case. In one case, uretero-calicial anastomosis was performed due to severe pyelic shrinkage. There were no significant complications. Native kidney nephrectomy was not required for further complications. All the patients operated on had optimum plasma creatinine levels with resolution of previous dilatation.

CONCLUSIONS

The initial percutaneous nephrostomy followed by open surgical repair using native ureter represents a definitive, valid and optimal alternative in terms of safety and preservation of renal function.

Cystoscopic extraction technique and external drainage rescue of a failed attempt to traverse a severe transplanted ureteral obstruction

Purpose

The aim of this research was to evaluate the efficacy of the cystoscopic extraction and external drainage techniques for unsuccessful antegrade stenting in transplanted severe ureteral obstruction.

Materials and Methods

A total of 26 patients with severe transplanted ureteral obstruction in whom the cystoscopic extraction technique and/or external drainage technique was performed were retrospectively evaluated. After the severe obstruction was successfully traversed, balloon dilatation followed by double-J stent insertion was performed.

Results

Of the 26 patients (male:female, 9:4; mean age, 38.1 years) who underwent failed ureteral stenting with the conventional procedure, 16 patients underwent successful stenting with the cystoscopic extraction technique, and 10 patients underwent successful stenting following external drainage. The mean serum creatinine of the 26 patients before stenting was 42.9 mg/dL (range, 32.7 to 54.1 mg/dL), which decreased to 10.3 mg/dL (range, 8.7 to 11.8 mg/dL) after stenting. The complications of the procedure were lower abdominal pain in 22 patients and gross hematuria in 9 patients. All complications were relieved with medical care within 3 to 5 days after the procedure. No major complications occurred.

Conclusions

The cystoscopic extraction technique and external drainage technique are safe and useful for traversing a severe transplanted ureteral obstruction after a failed conventional procedure.

Decrease in and management of urolithiasis after kidney transplantation

PURPOSE

Urolithiasis after kidney transplantation can involve several contributing factors and the treatment strategy is open to question. We determined the incidence and management of urolithiasis in kidney recipients.

MATERIALS AND METHODS

We retrospectively reviewed a single center series of 3,000 kidney graft recipients during 32 years to identify those with urolithiasis. We analyzed data by the prevalence per decade, including perioperative procedures (preoperative assessment, anastomosis type and urinary drainage) and long-term followup (urinary stenosis, time to presentation, size, site, treatment type, renal function and survival).

RESULTS

We identified 31 cases and noted a significant decrease in incidence from 2.1% to 0.6% during the 3 decades. Excluding 4 cases of donor in situ stones the mean time to diagnosis was 8.5 years. Surgical risk factors were ureteral obstruction in 41% of cases, infravesical obstruction in 14% and urinary-digestive anastomosis in 14%. A total of 12 cases (38%) were observed exclusively with 2 of spontaneous passage. With minor adaptations all mini-invasive procedures, including extracorporeal shock wave lithotripsy, endoscopy and percutaneous nephrolithotomy, were feasible in graft recipients. Antegrade procedures were facilitated by the ventral position of the graft. Eight patients (25%) were treated with open surgical ureteroureteral anastomosis.

CONCLUSIONS

Prevention with a perioperative Double-J® stent and early treatment of ureteral obstruction have decreased and stabilized the urolithiasis rate at around 0.6%. Careful surveillance or any currently available instrumental treatments of urinary stones can be valid options.