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

Early versus late removal of urinary catheter after kidney transplantation

BACKGROUND

The optimal treatment for end-stage kidney disease is kidney transplantation. During the operation, a catheter is introduced into the bladder and remains in place postoperatively to allow the bladder to drain. This decreases tension from the cysto-ureteric anastomosis and promotes healing. Unfortunately, urinary catheters can pose an infection risk to patients as they allow bacteria into the bladder, potentially resulting in a urinary tract infection (UTI). The longer the catheter remains in place, the greater the risk of developing a UTI. There is no consensus approach to the time a catheter should remain in place post-transplant. Furthermore, the different timings of catheter removal are thought to be associated with different incidences of UTI and postoperative complications, such as anastomotic breakdown.

OBJECTIVES

This review aimed to compare patients who had their catheter removed < 5 days post-transplant surgery to those patients who had their catheter removed ≥ 5 days following their kidney transplant. Primary outcome measures between the two groups included: the incidence of symptomatic UTIs, the incidence of asymptomatic bacteriuria and the incidence of major urological complications requiring intervention and treatment.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 April 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs comparing timing of catheter removal post-transplantation were eligible for inclusion. All donor types were included, and all recipients were included regardless of age, demographics or type of urinary catheter used.

DATA COLLECTION AND ANALYSIS

Results from the literature search were screened by two authors to identify if they met our inclusion criteria. We designated removal of a urinary catheter before five days (120 hours) as an 'early removal' and anything later than this as a 'late removal.' The studies were assessed for quality using the risk of bias tool. The primary outcome of interest was the incidence of asymptomatic bacteriuria. Statistical analyses were performed using the random effects model, and results were expressed as relative risk (RR) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Two studies (197 patients) were included in our analysis. One study comprised a full-text article, and the other was a conference abstract with very limited information. The risk of bias in the included studies was generally either high or unclear. It is uncertain whether early versus late removal of the urinary catheter made any difference to the incidence of asymptomatic bacteriuria (RR 0.89, 95% Cl 0.17 to 4.57; participants = 197; I2 = 88%; very low certainty evidence). Data on other outcomes, such as the incidence of UTI and the incidence of major urological complications, were lacking. Furthermore, the follow-up of patients across the studies was short, with no patients being followed beyond one month.

AUTHORS' CONCLUSIONS

A high-quality, well-designed RCT is required to compare the effectiveness of early catheter removal versus late catheter removal in patients following a kidney transplant. At the present time, there is insufficient evidence to suggest any difference between early and late catheter removal post-transplant, and the studies investigating this were generally of poor quality.

Incidence of and Risk Factors for Recurrent Urinary Tract Infections in Renal Transplant Recipients

Background

Recurrent urinary tract infections (rUTIs) are common after renal transplantation (RTx), and the impact on graft and patient survival remains controversial.

Objective

In this study, we investigate the incidence and risk factors for rUTIs in a cohort of RTx recipients and evaluate the effect on graft and patient survival.

Design setting and participants

A retrospective cohort of adult patients who underwent RTx at Rigshospitalet, Denmark, between 2014 and 2021 was evaluated in this study.

Outcome measurements and statistical analysis

Risk factors for rUTIs were explored with a multivariable cause-specific Cox proportional hazard analysis. The Kaplan-Meier estimate was used to assess overall survival.

Results and limitations

A total of 571 RTx recipients were included. The median age was 52 yr (interquartile range: 42-62 yr). Of the cases, 62% were deceased donor RTx. A total of 103 recipients experienced rUTIs. We found increasing age (hazard ratio [HR]: 1.02 per year increase, 95% confidence interval [95% CI]: 1.00-1.04, p = 0.02), female gender (HR: 2.1, 95% CI: 1.4-3.3, p < 0.001), history of lower urinary tract symptoms (HR: 2.3, 95% CI: 1.4-3.5, p = 0.001), and a UTI within 30 d of surgery (HR: 3.5, 95% CI: 2.1-5.9, p < 0.001) were associated with rUTIs. No influence of rUTIs on overall or graft survival was observed.

Conclusions

One in six patients experience rUTIs after RTx. Pre- and postoperative variables affect the risk of rUTIs, but none are easily modifiable. In this cohort, rUTIs did not affect the graft function or survival. The etiology of rUTIs remains poorly understood, and there is a continuous need to study how rUTIs can be reduced and treated optimally.

Patient summary

In this study, we looked at the risk factors for recurrent urinary tract infections in patients after kidney transplantation. We conclude that 21.5% of patients experience recurrent urinary tract infections 5 years after kidney transplantation. Multiple risk factors were found and should be taken into consideration by clinicians.

Utility of Pre-Transplant Bladder Cycling for Patients With a Defunctionalized Bladder. A Randomized Controlled Trial

OBJECTIVE

To study the necessity of pre-transplant programmed bladder cycling (PBC) in patients with defunctionalized bladder (DB).

METHOD

This RCT included renal transplant (RT) candidates with DB. Eligible patients were assigned to 2 groups, group I underwent PBC before RT and group II underwent direct RT into the DB. The primary outcome was to assess the efficacy of PBC in improving post- RT bladder capacity. Secondly, to compare its impact on early urological complications and 3-month voiding function and 1-year graft function and survival. Graft function was evaluated using serum creatinine and eGFR using MDRD equation.

RESULTS

Groups I included 23 patients and group II included 20 patients. The mean ±SD of bladder capacity was 88.7±11.7mL and 90.6 ±9.8mL in both groups, respectively (P = .5). In group I, PBC increased bladder capacity to 194.7 ±21.2 mL (P < .001). Targeted bladder capacity was achieved in 19 (82.6 %) patients and 2 patients developed UTI. At 3-months, bladder capacity, compliance and bladder contractility index improved significantly in both groups with a significant reduction in maximum detrusor pressure with no significant difference between both groups (P = .3,0.4, 0.2 and 0.8, respectively). Urinary leakage occurred in one (4.3%) and 3 patients (15%) in group 1 and 2, respectively (P = .2). At 1-year, no statistically significant differences in the median (IQR) serum creatinine (P = .05) and eGFR (P = .07) between both groups were noted.

CONCLUSION

Pre-transplant PBC for DB-patients provided no clinical advantage concerning post-operative urological complication, urodynamic criteria and graft function and survival.

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.

Influence of Graft Ureter Length, a Donor-Related Factor, on Urinary Tract Infections After Living-Donor Kidney Transplantation: A Single-Center Analysis of 211 Cases

Urinary tract infection (UTI) occurs in 25% of recipients of living-donor kidney transplantation (LDKT). Female sex, age, and anatomical abnormalities have been reported as recipient-related risk factors for UTI after LDKT; few studies have reported donor-related factors. We retrospectively examined UTI occurrence within 5 years of transplantation in recipients (n = 211) who underwent LDKT at our hospital between April 2011 and April 2021. All nephrectomies were performed using a retroperitoneal pure laparoscopic approach. The ureter was dissected at the lower level of the common iliac artery and trimmed to the shortest length, enough to reach the bladder using extra vesicular ureterocystoneostomy with a 3 cm submucosal tunnel. Twenty-nine recipients (13.7%) developed UTI within 5 years, and the median time to onset was 40.0 days. After adjusting for the well-known factors, including recipient sex, graft ureter length was an independent factor for UTI occurrence (HR 1.25, 95% CI 1.02∼1.53, p = 0.028) in the multivariate Cox regression analysis. The long ureter is usually trimmed, and the widest part is used for anastomosis, which may increase the possibility of reflux from the bladder to the ureter in the standard technique. The ureter length may be associated with the incidence of UTI after LDKT.

Vesicoureteral reflux treatment following kidney transplantation potentially prevents graft function deterioration and allows long-term graft survival

OBJECTIVES

The impact of vesicoureteral reflux post-kidney transplantation on graft survival remains unclear, and guidelines on appropriate vesicoureteral reflux management post-kidney transplantation are lacking. For this reason, we conducted a retrospective study on the impact of vesicoureteral reflux and its treatment on graft survival.

METHODS

We evaluated 347 consecutive kidney transplantation recipients, who also underwent a ureteroneocystostomy, between 1996 and 2012.

RESULTS

Vesicoureteral reflux was diagnosed in 55 cases (15.9%), with a median post-kidney transplantation duration of 50 months (range 0-172 months). Among these, 22 were monitored, 17 underwent transurethral collagen injections, and 16 received a ureteroneocystostomy. The 10-year graft survival rate was significantly lower in recipients with vesicoureteral reflux (68.9%) than in those without vesicoureteral reflux (84.4%) (P = 0.0165). Moreover, among the vesicoureteral reflux recipients, the 10-year graft survival rate was significantly higher in those whose vesicoureteral reflux was cured (80.1%) than in those whose vesicoureteral reflux persisted (53.6%) (P = 0.0062). Multivariate analysis showed that vesicoureteral reflux was significantly associated with both overall and death-censored graft loss (odds ratio 3.737 and 3.685; P = 0.0015 and P = 0.0052, respectively). Lastly, the incidence of interstitial fibrosis and tubular atrophy was higher in recipients with vesicoureteral reflux than in those without vesicoureteral reflux (P = 0.0009).

CONCLUSIONS

Post-kidney transplantation vesicoureteral reflux has a negative impact on long-term graft survival, and that treatment prevents graft deterioration. From the perspective of maintaining long-term graft function in kidney recipients, vesicoureteral reflux may be one of the most important complications to be addressed.

Peritoneal Dialysis for Potential Kidney Transplant Recipients: Pride or Prejudice?

Kidney transplantation (KT) is recognized as the gold-standard of treatment for patients with end-stage renal disease. Additionally, it has been demonstrated that receiving a pre-emptive KT ensures the best recipient and graft survivals. However, due to an overwhelming discrepancy between the organs available and the patients on the transplant waiting list, the vast majority of transplant candidates require prolonged periods of dialysis before being transplanted. For many years, peritoneal dialysis (PD) and hemodialysis (HD) have been considered competitive renal replacement therapies (RRT). This dualistic vision has recently been questioned by evidence suggesting that an individualized and flexible approach may be more appropriate. In fact, tailored and cleverly planned changes between different RRT modalities, according to the patient’s needs and characteristics, are often needed in order to achieve the best results. While home HD is still under scrutiny in this particular setting, current data seems to favor the use of PD over in-center HD in patients awaiting a KT. In this specific population, the demonstrated advantages of PD are superior quality of life, longer preservation of residual renal function, lower incidence of delayed graft function, better recipient survival, and reduced cost.

Allograft Vesicoureteral Reflux after Kidney Transplantation

Allograft vesicoureteral reflux (VUR) is a leading urological complication of kidney transplantation. Despite the relatively high incidence, there is a lack of consensus regarding VUR risk factors, impact on renal function, and management. Dialysis vintage and atrophic bladder have been recognized as the most relevant recipient-related determinants of post-transplant VUR, whilst possible relationships with sex, age, and ureteral implantation technique remain debated. Clinical manifestations vary from an asymptomatic condition to persistent or recurrent urinary tract infections (UTIs). Voiding cystourethrography is widely accepted as the gold standard diagnostic modality, and the reflux is generally graded following the International Reflux Study Committee Scale. Long-term transplant outcomes of recipients with asymptomatic grade I-III VUR are yet to be clarified. On the contrary, available data suggest that symptomatic grade IV-V VUR may lead to progressive allograft dysfunction and premature transplant loss. Therapeutic options include watchful waiting, prolonged antibiotic suppression, sub-mucosal endoscopic injection of dextranomer/hyaluronic acid copolymer at the site of the ureteral anastomosis, and surgery. Indication for specific treatments depends on recipient’s characteristics (age, frailty, compliance with antibiotics), renal function (serum creatinine concentration < 2.5 vs. ≥ 2.5 mg/dL), severity of UTIs, and VUR grading (grade I-III vs. IV-V). Current evidence supporting surgical referral over more conservative strategies is weak. Therefore, a tailored approach should be preferred. Properly designed studies, with adequate sample size and follow-up, are warranted to clarify those unresolved issues.

Living Donor Kidney Transplantation for a Recipient after 41 Years of Hemodialysis

Due to atrophic bladder, patients undergoing long-term dialysis experience vesicoureteral reflux and complicated urinary tract infections after kidney transplantation. A 58-year-old woman underwent living donor kidney transplantation after 41 years of dialysis. She had no contraindications, with good cardiac function and minimal artery calcification despite the long history of hemodialysis. Immunosuppression was initiated with tacrolimus, mycophenolate mofetil, prednisolone, and basiliximab. Ureteroneocystostomy with an antireflux technique was carefully conducted as her bladder volume was 15 mL. The postoperative clinical course was uneventful with immediate graft function. The bladder volume gradually increased to 81 mL at discharge, 3 weeks postoperatively. The patient was initially depressed due to frequent urination early post-transplant but recovered soon after as the bladder volume gradually increased to 400 mL. The patient has not yet reported a urinary tract infection episode. This case highlights living donor kidney transplantation-induced recovery of bladder function with careful ureteroneocystostomy, despite the long dialysis history.

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.

Update on the Management of Urological Problems Following Kidney Transplantation

Urological problems in kidney transplant recipients are not limited only to posttransplantation urological complications. These problems are a cause of significant patient mortality and morbidity that have wide-ranging effects on graft survival throughout the entire life of the graft. Ultimately, the transplant comprises a major portion of the urinary system; therefore, the transplant team should be prepared for foreseeable and unforeseeable urological problems in the short and long terms. These mainly include postoperative urological complications (urine leakage, ureteral stenosis, and vesicoureteral reflux), bladder outlet obstruction, and graft urolithiasis. In recent years, significant advances have been made in the management of urological complications, especially due to advances in endourologic interventions. The aim of this review is to summarize the management of urological problems after kidney transplantation in the context of the current literature.

Increasing bladder capacity and vesicoureteral reflux in pediatric kidney transplant patients

OBJECTIVES

To investigate the frequency of vesicoureteral reflux, and the relationship of pretransplant decreased bladder capacity and post-transplant vesicoureteral reflux in children undergoing kidney transplantation.

METHODS

A voiding cystourethrography was carried out in 172 pediatric kidney transplantation recipients before, and 4 months after, transplantation to evaluate bladder capacity and vesicoureteral reflux. The correlation of post-transplant vesicoureteral reflux with pretransplant bladder capacity, vesicoureteral reflux in the native kidney and the method of ureteral reimplantation (intravesical/extravesical) was analyzed. Atrophic bladder was defined as having ≤50% functional bladder capacity (age in years + 2) × 25 (mL) or ≤150 mL in patients aged >10 years.

RESULTS

Bladder capacity increased remarkably after transplantation in both post-transplant vesicoureteral reflux- group (from 180 to 253 mL) and vesicoureteral reflux+ group (from 82 to 171 mL). Voiding cystourethrography showed vesicoureteral reflux in 12 cases of kidney transplantation (7%; grade 1: 2, grade 2: 3, grade 3: 7). Pretransplant atrophic bladder was an independent risk factor of post-transplant vesicoureteral reflux (P = 0.004, hazard ratio 9.5). There was no difference in renal function between the vesicoureteral reflux- group and vesicoureteral reflux+ group at 4 months to 5 years post-transplantation.

CONCLUSIONS

Pretransplant atrophic bladder is a risk factor of post-transplant vesicoureteral reflux in pediatric patients. However, bladder capacity can remarkably increase after transplantation, and kidney function in the post-transplant vesicoureteral reflux+ group is stable.

Urologic complications in renal transplants

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