Independent risk factors for urological complications after deceased donor kidney transplantation

Surgical Complications Following Renal Transplantation in a Large Institutional Cohort

Background

Successful renal transplantation (RTx) relies on immunosuppression and an optimal surgical course with few surgical complications. Studies reporting the postoperative complications after RTx are heterogeneous and often lack systematic reporting of complications. This study aims to describe and identify postoperative short-term and long-term complications after RTx in a large institutional cohort and identify risk factors for a complicated surgical course.

Methods

The study is a retrospective single-center cohort of 571 recipients who underwent living or deceased donor open RTx between 2014 and 2021. Data were collected on background information and perioperative and postoperative data. Complications were defined as short-term (<30 d) or long-term (>30 d) after transplantation and graded according to the Clavien-Dindo classification. Multivariable logistic regression was performed to evaluate risk factors for serious short-term complications and multivariable time-dependent Cox regression to evaluate risk factors for long-term complications.

Results

A total of 351 patients received a graft from a deceased donor, and 144 of these grafts were on perfusion machine before transplantation. One or more short-term complications occurred in 345 (60%) patients. Previous RTx was associated with short-term Clavien-Dindo >2 complications in recipients (odds ratio = 2.08; 95% confidence interval [CI], 1.18-3.69; P = 0.01). Being underweight (body mass index <18.5) in combination with increasing age increased the odds of short-term Clavien-Dindo >2 and vascular complications. Increasing blood loss per 100 mL was associated with increased odds of short-term Clavien-Dindo >2 (odds ratio = 1.11; 95% CI, 1.01-1.21; P = 0.032). No associations were found for long-term complications after RTx. The 5-y cumulative incidence of graft loss was 12.6% (95% CI, 8.9-16.3).

Conclusions

Short-term complications are common after RTx, and risk factors for severe short-term complications include previous RTx, increasing age, and low body mass index. No risk factors were identified for severe long-term complications. Further studies should explore whether new surgical techniques can reduce surgical complications in RTx.

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.

Taguchi versus Lich-Grégoir Extravesical Ureteroneocystostomy in Kidney Transplantation: A Systematic Review

INTRODUCTION

Ureteric implantation of the transplanted ureter into native urinary bladder tissue in kidney transplantation recipients is essential for post-operative kidney function. We aimed to determine the effects of Taguchi versus Lich-Grégoir extravesical ureteroneocystostomy in kidney transplantation.

METHODS

We searched multiple databases (MEDLINE, Cochrane Library, and Web of Science), trial registries, and conference proceedings until March 2021. We included prospective studies comparing Taguchi and Lich-Grégoir ureteroneocystostomy in kidney transplantation. Two review authors independently screened the identified records, extracted data, evaluated the risk of bias using ROBINS-I, and assessed the certainty of evidence according to GRADE.

RESULTS

We identified 3 prospective studies with serious or critical risk of bias, leading to low-certainty evidence. We downgraded the risk of bias due to study limitations. Assessment and/or reporting of baseline imbalances, co-interventions, and confounding factors was insufficient in all included studies. The effect of Taguchi ureteroneocystostomy remains unclear.

CONCLUSION

Currently available evidence is not useful to determine the effect of Taguchi versus Lich-Grégoir ureteroneocystostomy in kidney transplantation. There is a need for methodologically better designed and executed studies, such as randomized controlled trials with long-term follow-up reporting baseline imbalances, co-interventions, and confounding factors.

Intraoperative assessment of ureter perfusion after revascularization of transplanted kidneys using intravenous indocyanine green fluorescence imaging

Background

Kidney transplantation is the most valuable renal replacement therapy. One of the most common urologic complications following kidney transplantation is ureter anastomosis leakage, which leads to high morbidity along with kidney graft loss. We hypothesized that indocyanine green (ICG) fluorescence videography can assess ureter perfusion after revascularization of transplanted kidneys.

Methods

We conducted a prospective cross-sectional study in end-stage renal disease patients who underwent deceased donor kidney transplantation at Ramathibodi Hospital from September 2019 to January 2020. The segments of transplanted ureters were categorized as having good or poor perfusion based on the percentage from ICG fluorescence videography images. Then the results from ICG fluorescence videography were compared with histopathology which is considered the gold standard.

Results

Thirty-one sections of dissected ureters were evaluated from 10 patients. Compared with pathological diagnosis of ureteral ischemia, ICG videography had sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio of 100%, 92.6%, 66.7%, 100%, and 14, respectively. Accuracy was 93.6%. The area under the curve of ICG fluorescence videography was 0.96. The average ureter length that maintained good perfusion was 14 cm from the ureteropelvic junction. Adverse events from ICG were not observed in this study.

Conclusions

We conclude that ICG fluorescence videography is beneficial for detection of early ureteral ischemia in kidney transplantation patients, with negligible adverse events. However, further studies with larger numbers of patients are necessary to confirm our results and clinical outcomes regarding complication rates.

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.

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.

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.

Timely surgical intervention for ureteric complications ensures adequate graft function in renal transplantation: a 10-year review

BACKGROUND

Ureteric complications can cause significant morbidity in renal and simultaneous pancreas-kidney (SPK) transplantation. This 10-year review identified transplant patients with ureteric complications necessitating surgical intervention in an Australian tertiary centre.

METHODS

The hospital records were scrutinized in detail to identify all patients who underwent renal or SPK transplantation from 1 June 2009 to 31 May 2019 with subsequent surgical management of ureteric complications. A case series of patients with ureteric complications was generated and findings were analysed.

RESULTS

A total of 893 renal and SPK transplants were performed over the 10-year period. Ten of these (1.12%; seven renal and three SPK) had ureteric complications. All were managed surgically. Five of the 10 had ureteric leaks (0.56%); three had ureteric strictures (0.34%), one had ureteric obstruction from extraluminal compression (0.11%) and one had both leak and stricture (0.11%). All 10 patients underwent ureteric reimplantation. Two patients required more than one operation for their ureteric complication. No graft loss or surgical mortality occurred. All 10 patients currently have functioning kidney transplants and none require maintenance dialysis.

CONCLUSION

We report a low rate (1.12%) of ureteric complications in our renal and SPK transplants. Our standard practice of definitive correction by ureteric reimplantation is proving successful. The authors confirm that appropriate surgery is a viable and durable option in renal transplant patients with excellent graft outcomes.

Consensus on definition and severity grading of lymphatic complications after kidney transplantation

BACKGROUND

The incidence of lymphatic complications after kidney transplantation varies considerably in the literature. This is partly because a universally accepted definition has not been established. This study aimed to propose an acceptable definition and severity grading system for lymphatic complications based on their management strategy.

METHODS

Relevant literature published in MEDLINE and Web of Science was searched systematically. A consensus for definition and a severity grading was then sought between 20 high-volume transplant centres.

RESULTS

Lymphorrhoea/lymphocele was defined in 32 of 87 included studies. Sixty-three articles explained how lymphatic complications were managed, but none graded their severity. The proposed definition of lymphorrhoea was leakage of more than 50 ml fluid (not urine, blood or pus) per day from the drain, or the drain site after removal of the drain, for more than 1 week after kidney transplantation. The proposed definition of lymphocele was a fluid collection of any size near to the transplanted kidney, after urinoma, haematoma and abscess have been excluded. Grade A lymphatic complications have a minor and/or non-invasive impact on the clinical management of the patient; grade B complications require non-surgical intervention; and grade C complications require invasive surgical intervention.

CONCLUSION

A clear definition and severity grading for lymphatic complications after kidney transplantation was agreed. The proposed definitions should allow better comparisons between studies.

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.

Association of Double-J Stenting in Renal Transplant Patients With Urinary Tract Colonization and Infections in a Multidrug-resistant Microbe Endemic Nosocomial Environment

PURPOSE

We investigated the association of ureteral stenting after kidney transplantation with the development of urinary tract infections (UTIs) and/or urinary tract colonization, in a hospital environment considered endemic for multidrug resistant (MDR) Gram-negative Enterobacteriaceae.

METHODS

Seventy-five recipients of deceased donor grafts were divided in groups A and B. Group A (with subgroups A1 and A2) included 45 transplanted patients without urinary stenting, and group B 30 patients with stenting. Subgroup A1 consisted of 30 patients transplanted before 2006, and A2 of 15 patients transplanted after 2006, when MDR, mainly carbapenem-resistant, Enterobacteriaceae, frequency has risen in our hospital.

RESULTS

The incidence and the number of UTIs per patient were significantly higher in patients without stenting compared to those with stenting. (Group A: 32/45 vs group B: 9/30, P < .001, and group A: 2.86 ± 0.43 vs group B: 0.6 ± 0.19, P < .01 respectively). Patients without stenting tended to have a higher frequency of recurrent UTIs compared to those with stenting (group A: 16/45 vs group B: 4/30, P < .05). Asymptomatic bacteriuria was more frequent in the patients with stent (group A: 8/45 vs group B: 14/30, P < .05). Further sub-comparison of the A1 and A2 subgroups with group B did not change the statistical results.

CONCLUSIONS

There is no clinically significant association of ureteral stenting after kidney transplantation with the high frequency of MDR Gram-negative bacteria in our hospital.

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.

Perigraft fluid collections after kidney transplantation: Does the type of donor (uncontrolled donation after circulatory death vs. donation after brain death) have a role?

Introduction

Perigraft fluid collection (PFC) is a common complication after kidney transplant. Its etiology is not clear and not all the causes have been identified. The influence of the type of donor has never been evaluated. Our aim was to compare the incidence, severity and management of PFC in recipients of grafts from uncontrolled donors after circulatory death (DCD) with normothermic extracorporeal membrane oxygenation (NECMO) versus recipients of grafts from donors after brain death (DBD).

Material and methods

We conducted a retrospective cohort study of 300 kidney transplants performed in our center between 2007 and 2012. Patients were divided in two groups: 150 recipients of Maastricht II DCD graft and 150 recipients of the DBD graft. Incidence, severity according to Clavien scale and management were analyzed in both groups, and comparison was carried out using Chi-square.

Results

Of the 300 kidney recipients analyzed, 93 (31.4%) suffered PFC, showing no difference between DBD (32.0%) and DCD (30.8%) groups (p = 0.9). Complicated PFC rate (defined as a PFC generating vascular compression, fever or urinary tract obstruction) was 22.9% in the DBD group versus 22.2% in the DCD group (p = 1); most complicated PFC were due to urinary tract obstruction (81%), with no difference between the groups (p = 1). Concerning Clavien scale, 78.5% of the PFC in our series were Clavien I, 19.4% Clavien IIIa and 2.2% Clavien IIIb, with no difference between both groups (p = 1).

Conclusions

PFC is a frequent complication that appears in a third of our patients, showing no difference in the incidence or severity between DBD and uncontrolled DCD graft recipients.

Surgical Complications After Kidney Transplantation

Since the first successful organ transplant conducted between twins in 1954, kidney transplant has evolved considerably over the past 50 years. Kidney transplant plays an important role in the treatment of end-stage kidney disease to improve the quality of life and prolong the life of patients. Despite significant advances, postoperative medical and surgical complications still represent important causes of morbidity and mortality. Many problems can be avoided through prophylactic correction of abnormalities detected during the preoperative evaluation; however, it is critical that technical mishaps at all stages of the transplant process (donor nephrectomy, benchwork preparation, and implant) be prevented and that careful postoperative monitoring be carried out, including thorough examination by attending physicians. However, despite these advances, surgical complications still present serious problems in kidney transplant recipients.

Atrophic bladder in long-term dialysis patients increases the risk for urological complications after kidney transplantation

OBJECTIVES

To evaluate the risk for urological complications after kidney transplantation at a single medical center in Japan.

METHODS

In the present study, 408 kidney recipients (255 men, 153 women) were enrolled. There were 349 living and 59 deceased donors. The average age of the recipients was 42.5 ± 13.5 years, and the average pretransplant dialysis period was 71.8 ± 88.2 months. Ureteroneocystostomy was carried out on 347 patients, and ureteroureterostomy on 61 patients. We investigated the relationship between pretransplant duration of dialysis and bladder capacity, and examined the risk factors for urological complication. We also evaluated the incidence of vesicoureteral reflux in 191 recipients who underwent ureteroneocystostomy during transplantation.

RESULTS

The preoperative duration of dialysis therapy showed a significant negative correlation with bladder capacity (R²  = 0.33, P < 0.001). The overall urological complication rate was 3.4% (14 patients), including urinary leakage (12 patients) and ureteral stricture (two patients). Univariate analysis showed that atrophic bladder, long-term dialysis therapy, deceased donor and ureteroureterostomy were associated with a higher incidence of urological complications (odds ratio 8.05, 4.43, 3.42 and 3.35; P < 0.01, P = 0.01, P = 0.04 and P = 0.04, respectively). Furthermore, multivariate analysis showed that atrophic bladder was the only significant factor associated with urological complications (odds ratio 10.37; P = 0.01). Among 191 recipients, vesicoureteral reflux was observed in 32 (16.8%). The incidence of vesicoureteral reflux was significantly higher in patients with atrophic bladder.

CONCLUSIONS

Bladder atrophy in renal transplant recipients after long-term dialysis therapy is associated with a higher risk of urological complications.

Minimizing the Number of Urological Complications After Kidney Transplant: A Comparative Study of Two Types of External Ureteral Stents

OBJECTIVES

The aim of this study was to evaluate the effects of 2 types of external ureteral stents on the number of urological complications after kidney transplant.

MATERIALS AND METHODS

Data were retrospectively collected from 366 consecutive transplants performed between January 2013 and January 2015 in our hospital, in which an external ureteral stent was placed during surgery and removed after 9 days. Urological complications were defined as urinary leakage or ureteral stenosis requiring percutaneous nephrostomy placement.

RESULTS

A total of 197 patients received a straight stent with 2 larger side holes (type A; 8F "Covidien" tube; Covidien, Dublin, Ireland) and 169 patients received a single J stent with 7 smaller side holes (type B; 7F "Teleflex" single J stent; Teleflex Medical, Athlone, Ireland). We found a significantly higher number of percutaneous nephrostomy placements with type A stents, with 34 (17%) versus 16 (9%) in type B (P = .030). Reason for percutaneous nephrostomy placement, occurrence of stent dysfunction, and need for early removal (< 8 days) were equal in both groups (P = .397), whereas incidence of rejection and urinary tract infection were higher in type B stent group. Patient and graft survival did not differ between the groups.

CONCLUSIONS

Use of the type B stent was associated with less urological complications compared with the type A stent.

Urological complications after renal transplantation - a single centre experience

Introduction

Urological complications after renal transplantation occur in between 2.5% and 30% of all graft recipients. The aim of the study was to present 7 years of experience in urological treatment of patients with a transplanted kidney. We aimed to identify retrospectively late urological complications in renal transplant recipients at a single center and analyze the treatment modalities and their outcome.

Material and methods

Between January 2008 and December 2014, a total of 58 patients after KTX were treated in the Department of Urology because of post-transplant urological complications that occurred during follow-up at the Transplant Outpatient Department. Retrieved data were analysed in retrospectively.

Results

In the group of 38 patients with ureteral stenosis (Clavien grade III), 29 patients underwent endoscopy, 8 open surgical procedures and one both endoscopic and open operation. Ten patients were admitted with symptomatic lymphocoele (Clavien III), of which 9 were successfully treated with drainage and one with surgical marsupialization. Because of urolithiasis in the grafted kidney (Clavien grade III), 4 patients were treated with ureterorenoscopic lithotripsy (URSL) and one only with the extracorporeal shock wave lithotripsy (ESWL) procedure. Five urethral strictures plasties and one graftectomy because of purulent pyelonephritis were also conducted. The average age in the group of recipients who experienced urologic complications was similar (46.1 vs. 47.8) to those without complications. There was no vesicoureteral reflux or ureteral necrosis requiring surgical intervention, no graft loss and death related to urological complication and treatment.

Conclusions

Most complications could be successfully treated with endourological procedures. The kidney function improved in the majority of patients.

Ureteral length in live donor kidney transplantation; Does size matter?

The aim of this study was to evaluate the role of ureteral length on urological complications. Data were retrospective collected from the INEX-trial database, a RCT to compare the intravesical to the extravesical ureteroneocystostomy. Ureteral length was measured in 198 recipients and used to divide recipients into three categories based on interquartile ranges: short (≤8.5 cm), medium (8.6-10.9 cm) and long ureters (≥11 cm). Urological complications were defined as the number of percutaneous nephrostomy placements (PCN). Fifty recipients fell into the short, 98 into the medium and 50 recipients into the long ureter category. Median follow-up was 26 (range 2-45) months. There was no significant difference in number of PCN placements between the categories. There were 9 (18%) PCN placements in the short ureter category, 21 (20%) in medium ureter category and 10 (21%) in the long ureter category, P = 0.886. Risk factor analysis for gender, arterial multiplicity and type of ureteroneocystostomy showed no differences in PCN placements between the three ureteral length categories. We conclude that ureteral length alone does not seem to influence the number of urological complications.

Independent risk factors for early urologic complications after kidney transplantation

Urologic complications are the most frequent technical adverse events following kidney transplantation (KTX). We evaluated traditional and novel potential risk factors for urologic complications following KTX. Consecutive KTX recipients between December 1, 2006 and December 31, 2010 with at least six-month follow-up (n = 635) were evaluated for overall urologic complications accounting for donor, recipient, and transplant characteristics using univariate and multivariate logistic regression. Urologic complications occurred in 29 cases (4.6%) at a median of 40 d (range 1-999) post-transplantation and included 17 ureteral strictures (2.6%), five (0.8%) ureteral obstructions due to donor-derived stones or intraluminal thrombus, and seven urine leaks (1.1%). All except two complications occurred within the first year of transplantation. Risk factors for urologic complications on univariate analysis were dual KTX (p = 0.04) and renal artery multiplicity (p = 0.02). On multivariate analysis, only renal artery multiplicity remained significant (aHR 2.4, 95% confidence interval 1.1, 5.1, p = 0.02). Donation after cardiac death, non-mandatory national share kidneys, donor peak serum creatinine > 1.5 mg/dL or creatinine phosphokinase > 1000 IU/L, and donor down time were not associated with urologic complications. Our data suggest that donor artery multiplicity is an independent risk factor for urologic complications following KTX.

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.