Value of routine voiding cystourethrography after renal transplantation

Vesicoureteral reflux postoperative radical nephroureterectomy for upper urinary tract urothelial carcinoma: A case report

Introduction

Primary Upper tract urothelial carcinoma (UTUC) is a rare subtype of urothelial carcinoma and has an unknown incidence and prevalence in Yemen. Radical nephroureterectomy (RNU) with bladder cuff removal is the standard treatment for UTUC.

Case presentation

We present a 67-year-old male patient who developed grade II vesicoureteral reflux (VUR) on the left side of the urinary tract after undergoing right-sided RNU for non-invasive UTUC. Follow-up examinations at one-, three-, and six-month post-surgery revealed no evidence of kidney diseases. The patient's recovery has been satisfactory, and ongoing regular follow-ups are being maintained.

Conclusion

Vigilant monitoring of VUR presence and effective management following RNU is crucial to minimize complications and preserve renal function. The underlying mechanisms linking VUR development and RNU remain unclear, necessitating further research.

Diagnostic and therapeutic management of vesico-ureteral reflux in pediatric kidney transplantation-Results of an online survey on behalf of the European Society for Paediatric Nephrology

BACKGROUND

Vesico-ureteral reflux (VUR) is considered to be a risk factor for recurrent febrile urinary tract infections and impaired renal transplant survival.

METHODS

An online survey supported by the European Society for Paediatric Nephrology was designed to evaluate current management strategies of VUR in native and transplanted kidneys of recipients aged <18 years.

RESULTS

Seventy-three pediatric transplant centers from 32 countries contributed to the survey. All centers performed urological evaluation prior to pediatric kidney transplantation (KTx) with subsequent interdisciplinary discussion. Screening for VUR in native kidneys (30% in all, 70% in selected patients) led to surgical intervention in 78% (11% in all, 89% in selected patients) with a decided preference of endoscopic intervention over ureterocystoneostomy. Following KTx, continuous antibiotic prophylaxis was applied in 65% of the patients and screening for allograft VUR performed in 93% of selected patients. The main management strategies of symptomatic allograft VUR were continuous antibiotic prophylaxis (83%) and surgical treatment (74%) (endoscopic intervention 55%, redo ureterocystoneostomy 26%).

CONCLUSIONS

This survey demonstrates the high variability in the management of VUR in pediatric KTx recipients, points to knowledge gaps, and might serve as a starting point for improving the care for patients with VUR in native and transplanted kidneys.

Role of Contrast-Enhanced Voiding Urosonography in the Evaluation of Renal Transplant Reflux - Comparison with Voiding Cystourethrography and a New Classification

Vesicoureteral reflux (VUR) is a common urological complication in renal transplant patients.

THE AIM

of this study is to evaluate the performance of contrast-enhanced voiding urosonography (CEvUS) in the diagnosis and classification of reflux into the renal allograft, to evaluate and classify VUR into the allograft using voiding cystourethrography (VCUG) and CEvUS, to compare the two methods, and to propose a new classification of reflux into the allograft based on CEvUS and VCUG assessment, in line with the international reflux grading system.

MATERIALS AND METHODS

 From January 2017 to July 2019, 84 kidney transplant patients were enrolled. All patients underwent VCUG and CEvUS.

RESULTS

 In 76 cases there was agreement between VCUG and CEvUS (90 %) (Kappa = 0.7). The sensitivity of CEvUS using VCUG as the gold standard was 90 %, and the specificity was 92 %. Of the 7 cases diagnosed by VCUG and not by CEvUS, 6 were grade 1 and 1 was grade 2.

CONCLUSION

 Transplant patients with reflux symptoms should undergo CEvUS. If the outcome is negative, VCUG should be performed. The classification that we propose is better suited to describe VUR in transplant patients, because it is simpler and takes into account whether reflux occurs not only during urination but also when the bladder is relaxed.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

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.

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.

Minimal-invasive management of urological complications after kidney transplantation

Kidney transplantation represents the gold standard treatment option for patients with end-stage renal disease. Improvements in surgical technique and pharmacologic treatment have continuously prolonged allograft survival in recent years. However, urological complications are frequently observed, leading to both postoperative morbidity and putative deterioration of allograft function. While open redo surgery in these patients is often accompanied by elevated surgical risk, endoscopic management of urological complications is an alternative, minimal-invasive option. In the present article, we reviewed the literature on relevant urological postoperative complications after kidney transplantation and describe preventive approaches during the pre-transplantation assessment and their management using minimal-invasive approaches.

Results of Haberal's Corner-Saving Ureteral Anastomosis Technique for Renal Transplantation: A Retrospective Study

BACKGROUND

Urological complications after renal transplantation (RT), including urine leaks, remain the most common type of surgical complications in the early post-transplant period. In this study we evaluated 324 consecutive RTs recipients in whom Haberal's corner-saving anastomosis technique was used for ureteroneocystostomy.

MATERIAL AND METHODS

Since January 2018, 461 RTs were performed at our center. Haberal's corner-saving anastomosis technique was used in 324 of these 461 RTs and the effectiveness of the technique was analyzed retrospectively. There were 115 female patients and 209 male patients, with a mean age of 42.1 ± 13.9 years. The most common etiology resulting in RT was hypertension among the recipients.

RESULTS

We observed 8 (2.4%) ureteral complications in 7 recipients as follows: ureteral stenosis in 2 recipients (0.6%), anastomotic leaks in 1 (0.3%), concomitant leak-stenosis in 1 (0.3%), and vesicoureteral reflux in 3 (0.9%). Six complications were treated with interventional radiological techniques and 2 were treated surgically. There was no graft and patient loss in the event of urological complications.

CONCLUSION

Because of the low complication rate, we believe that Haberal's corner-saving ureteral anastomosis technique is a safe method for performing a ureteroneocystostomy.

Endourological application of polydimetilsiloxane in patients with symptomatic vesicoureteral reflux in the kidney graft

OBJECTIVE

To identify the results of polydimethylsiloxane application in the endourological management of symptomatic vesicoureteral reflux to the kidney graft and to determine the factors associated with persistent symptoms and with vesicoureteral reflux.

MATERIAL AND METHODS

We included 23 patients diagnosed with symptomatic VUR in kidney graft, evaluated from January 2010 to August 2018 in the High Specialty Medical Unit # 14 in Veracruz. These patients received endourological application of polydimethylsiloxane. The descriptive analysis was carried out, and, if possible, the relative risk measures for clinical failure (CF) were determined with odds ratio (OR).

RESULTS

18 (78.3%) patients presented clinical success (CS). There was a significant difference in the mean age (CS 30.61±9.7, CF 46.0±11.46; U Mann Whitney, P=.037), and in the number of episodes of AGPN prior to the application of PDMS (CS 2.27±1.27, CF 3.6±0.89, U Mann Whitney, P=.019). The most frequently identified pathogen was E. Coli, with 45.4%. VUR resolution was observed in 47.8% of the cases. There was a decreased degree of VUR in 73.9% of cases. A lower degree of VUR was determined as a protective factor for CF (OR: 0.031, 95% CI: 0.002-0.437, with P=.008).

CONCLUSIONS

The endourological application of PDMS proved to be useful in the management of patients with symptomatic VUR in kidney graft, as it decreased the VUR degree and allowed CS in most cases.

Host and pathogen factors in Klebsiella pneumoniae upper urinary tract infections in renal transplant patients

PURPOSE

To analyse the role of virulence factors (VFs) and host in Klebsiella pneumoniae upper urinary tract infections (UTIs) in renal transplant (RTx) recipients.

METHODOLOGY

Clinical and demographic data were registered prospectively. Phylogenetic background of K. pneumoniae isolates was analysed by PCR melting profiles (MP) and the following VFs genes: fimH-1, uge, kpn, ycfM, mrkD, rmpA, magA, hlyA, cnf-1, irp-1, irp-2, fyuA, entB, iutA, iroN by PCR.

RESULTS

We studied urine cultures and clinical data from 61 episodes of K. pneumoniae UTI in 54 RTx recipients. There were 32 cases of AB (53%), 10 cases of lower UTI (16%), 19 cases of AGPN (31%), including six cases of bacteraemia. In total, 74 % of strains were extended-spectrum beta-lactamase+, and there were two carbapenemase-producing strains. PCR MP typing showed a diverse population with 52 different genetic profiles of K. pneumoniae. Analysis of the DNA profiles indicated 45 unrelated, unique genotypes and 7 related (16 isolates from 15 patients) genotypes. Urine flow impairment emerged as an independent predictor of K. pneumoniae upper UTIs (OR 14.28, CI 2.7-75.56, P 0.002), while we did not find any association between the profile of VFs and developing upper UTIs. The prevalence of the uge gene was lower in RTx patients on everolimus when compared to isolates from patients not receiving mTOR inhibitors (33.3 % vs 82.8 % P<0.05).

CONCLUSIONS

K. pneumoniae upper UTI may be a marker of urine flow impairment. Bacterial VFs could not discriminate between upper and lower UTIs. However, immunosuppression may influence the selection of particular VFs.

A survey of Canadian renal transplant surgeons: Use of ureteric stents and technique of the ureteroneocystotomy

INTRODUCTION

The role of ureteric stenting in renal transplant has been well-demonstrated. The goal of this survey was to determine the utilization of ureteric stents by Canadian transplant surgeons, and how the ureteroneocystotomy and followup is performed.

METHODS

An online survey was sent to the 40 surgeon members of the Canadian Society of Transplantation. The primary outcome was the rate of ureteric stent use at the time of renal transplantation. The secondary outcomes were the ureteric stent dwell time, use and type of prophylactic antibiotics, and the use of routine post-transplant ultrasonography.

RESULTS

All respondents (25) used ureteric stent routinely and 92% remove the stent between four and six weeks postoperatively. Prophylactic antibiotics were used 64% of the time for ureteric stent removal. The majority of surgeons do not routinely perform a post-stent removal ultrasound. Fifty-six percent of respondents perform a refluxing anastomosis.

CONCLUSIONS

Ureteric stents are routinely used in renal transplant in Canada. Areas for improvement and topics of debate identified from this survey are the need for peri-stent removal antibiotics, the role of post-stent removal ultrasound, the duration of stent dwell time, and the need for a non-refluxing ureteroneocystotomy.

Renal function outcomes in pediatric patients with symptomatic reflux into the transplanted kidney treated with redo ureteroneocystostomy

INTRODUCTION

Asymptomatic post-renal transplant reflux is common but only 5-10% patients are diagnosed with vesico-ureteral reflux in the setting of post-transplant febrile urinary tract infections, requiring redo ureteroneocystostomy (redo-UNC). Here we report the renal function outcomes of 37 such patients, stratified by lower urinary tract (LUT) status.

OBJECTIVE

We hypothesized that those with pre-transplant LUT dysfunction would have lower glomerular filtration rate (GFR) on follow-up.

STUDY DESIGN

Using procedure codes, 37 patients who underwent renal transplant followed by redo-UNC for transplant reflux at our institution between 1991 and 2014 were identified. Patient characteristics and GFR levels from four different time points were recorded. Comparisons were made between those with and without LUT dysfunction, using Fisher's exact, Wilcoxon rank sum, or signed-rank tests. Generalized estimating equations were constructed to account for the clustered nature of GFR within each LUT group and to assess their change over time.

RESULTS

Twelve patients (32%) had pre-transplant LUT dysfunction. The proportion of males in this group was significantly higher (75% vs. 32%, p = 0.032), and there was no statistical difference towards presenting earlier with post-transplant reflux (1.4 vs. 2.3 years, p = 0.087). After an average of 4.9 years, the median GFRs were similar between the two groups (53 mg/dL vs. 58 mg/dL, p = 0.936). There was no significant difference in GFR at this last follow-up time point in patients with and without LUT dysfunction.

DISCUSSION

Vesicoureteral reflux in the setting of renal transplantation is common and doesn't often require repair. In our series, we found that those with LUT dysfunction did not present statistically sooner with symptomatic transplant reflux. Longer-term follow-up did show a decline in GFR but did not reveal a difference in GFR in patients' with and without LUT dysfunction.

CONCLUSIONS

Pediatric post-transplant GFR after open redo ureteral reimplant decreases over time in similar fashion in patients with symptomatic reflux regardless of whether they have LUT dysfunction or normal anatomy. Vigilance should apply to the recognition, treatment, and follow-up of all symptomatic transplant reflux regardless of LUT status.

Unexpected Vesicoureteral Reflux Into a Nonfunctioning Transplant Kidney on Renal Scintigraphy

Vesicoureteral reflux after renal transplantation is associated with increase risk of urinary tract infections, renal scarring, and graft failure. We describe a case of a 46-year-old woman with 2 transplant kidneys, one functioning and another nonfunctioning, presenting with pelvic pain after a bilateral periureteral bulking procedure. Diuretic renography was performed to exclude iatrogenic ureteral obstruction. This showed a normally functioning transplant kidney without obstruction and subsequent vesicoureteral reflux into the collecting system of the nonfunctioning transplant kidney. This inadvertent indirect nuclear cystogram illustrates an unusual imaging presentation of a common disease process requiring further treatment.

Clinicopathologic Impact of Early Medullary Ray Injury in Patients Following Kidney Transplantation

BACKGROUND

Previously, we explored the histopathologic characteristics of medullary ray injury (MRI) inducing interstitial fibrosis and tubular atrophy (IF/TA) to determine its etiologies, which include calcineurin inhibitor (CNI) toxicity and urologic complications. However, we did not examine the effects of these etiologies on long-term kidney allograft prognosis, because biopsy timing differed among cases.

AIM

We examined the influence of early MRI on kidney allograft prognosis using protocol biopsies taken within a 3-month time frame.

METHODS

We defined early MRI as tubular degeneration with interstitial edema or mild fibrosis localized to the medullary ray. We divided 53 protocol biopsies into 2 groups, with and without early MRI. Early MRI+ cases with isometric vacuolization were classified as CNI toxicity; those with Tamm-Horsfall protein in the interstitium and a thyroidlike appearance were classified as urinary tract system abnormalities; remaining cases were classified as "others." We compared changes in serum levels of creatinine (sCr) over 3 years and fibrosis extent at 1 year.

RESULTS

The sCr levels were significantly higher in the MRI+ group than the MRI- group at 3 years (P = .024). Examining the 3 MRI+ subgroups, only the MRI+ urinary tract system abnormalities group had significantly high sCr levels compared to the MRI- group (P = .019). The MRI+ group showed significant signs of IF/TA at 1 year.

CONCLUSIONS

Early MRI after kidney transplantation was significantly more likely to develop IF/TA at 1 year and had higher sCr levels at 3 years. In such cases, intervention might preserve graft function over the long term.

Vesicoureteral Reflux in Kidney Transplantation

BACKGROUND

Vesicoureteral reflux (VUR) is frequently found after transplantation, but its impact on graft function, urine tract infection, and graft loss remains uncertain. Therefore our objective was to evaluate the effects of VUR on the outcome of renal transplantation.

MATERIAL AND METHODS

We included 1008 adult renal transplant recipients of whom a 1-week posttransplant voiding cystourethrogram was available. Study end points included occurrence of bacteriuria, renal function, and graft survival.

RESULTS

In total, 106 (10.5%) of 1008 graft recipients had a diagnosis of VUR on voiding cystography. The incidence of bacteriuria was comparable in the reflux and nonreflux group (17% vs 17.4%, P = .91). There was no significant difference in renal function at 3 months and 1 year in patients with and without VUR. One- and 5-year graft survival in patients with VUR was 85.8% and 82.1% compared to 87.3% and 83.0% in patients without VUR ( P = .68 and P = .80).

CONCLUSION

Posttransplant VUR has no correlations with early bacteriuria, renal function, and graft survival.

Holmium Laser Enucleation of the Prostate With Percutaneous Nephrostomy Into the Transplanted Kidney in Patient With Severe Benign Prostatic Hyperplasia With Vesicoureteral Reflux - A Case Report

A 66-year-old male, who had received renal transplantation 10 years before, was admitted to our hospital with urinary retention. The prostate volume was 169.2 ml. Furthermore, grade 5 vesicoureteral reflux (VUR) was shown in the cystography. Holmium laser enucleation of prostate (HoLEP) was performed, and percutaneous nephrostomy to the transplanted kidney was performed simultaneously to prevent from severe perioperative infection. After that, renal graft function improved and no urinary retention reoccurred, although surgical repair against VUR was necessary 10 months after HoLEP. We conclude that surgical treatment for BPH after kidney transplantation should be strongly considered with care for infections.

Body mass index and outcome in renal transplant recipients: a systematic review and meta-analysis

BACKGROUND

Whether overweight or obese end stage renal disease (ESRD) patients are suitable for renal transplantation (RT) is often debated. The objective of this review and meta-analysis was to systematically investigate the outcome of low versus high BMI recipients after RT.

METHODS

Comprehensive searches were conducted in MEDLINE OvidSP, Web of Science, Google Scholar, Embase, and CENTRAL (the Cochrane Library 2014, issue 8). We reviewed four major guidelines that are available regarding (potential) RT recipients. The methodology was in accordance with the Cochrane Handbook for Systematic Reviews of Interventions and written based on the PRISMA statement. The quality assessment of studies was performed by using the GRADE tool. A meta-analysis was performed using Review Manager 5.3. Random-effects models were used.

RESULTS

After identifying 5,526 studies addressing this topic, 56 studies were included. We extracted data for 37 outcome measures (including data of more than 209,000 RT recipients), of which 26 could be meta-analysed. The following outcome measures demonstrated significant differences in favour of low BMI (<30) recipients: mortality (RR = 1.52), delayed graft function (RR = 1.52), acute rejection (RR = 1.17), 1-, 2-, and 3-year graft survival (RR = 0.97, 0.95, and 0.97), 1-, 2-, and 3-year patient survival (RR = 0.99, 0.99, and 0.99), wound infection and dehiscence (RR = 3.13 and 4.85), NODAT (RR = 2.24), length of hospital stay (2.31 days), operation duration (0.77 hours), hypertension (RR = 1.35), and incisional hernia (RR = 2.72). However, patient survival expressed in hazard ratios was in significant favour of high BMI recipients. Differences in other outcome parameters were not significant.

CONCLUSIONS

Several of the pooled outcome measurements show significant benefits for 'low' BMI (<30) recipients. Therefore, we postulate that ESRD patients with a BMI >30 preferably should lose weight prior to RT. If this cannot be achieved with common measures, in morbidly obese RT candidates, bariatric surgery could be considered.

Ureterovesical anastomotic techniques for kidney transplantation: a systematic review and meta-analysis

No consensus exists about which ureterovesical anastomosis technique to use for kidney transplantation. The aim of this systematic review was to compare the existing techniques in relation to the risk of urological complications. All studies that compared ureterovesical anastomotic techniques in kidney transplantation were included. Study endpoints were urinary leakage, ureteral stricture, vesicoureteral reflux and hematuria. Subanalyses of stented and nonstented techniques were performed. Two randomized clinical trials and 24 observational studies were included. Meta-analyses were performed on the Lich-Gregoir (LG) versus Politano-Leadbetter (PL) techniques and LG versus U-stitch (U) techniques. Compared with the PL technique, the LG technique had a significantly lower prevalence of urinary leakage (risk ratio (RR): 0.47, 95% confidence interval (CI): 0.30 to 0.75) and a significantly lower prevalence of hematuria when compared with both PL and U techniques (RR: 0.28, 95% CI: 0.16 to 0.49 and RR: 0.23, 95% CI: 0.11 to 0.50, respectively), regardless of ureteral stenting. There was no difference in the prevalence of ureteral strictures or vesicoureteral reflux between the various techniques. Of the three most frequently used ureterovesical anastomotic techniques, the LG technique results in fewer urological complications than the PL and U techniques.