Urological complications: analysis and management of 1525 consecutive renal transplantations

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.

Robotic-assisted Laparoscopic Repair of Kidney Transplant Ureteral Strictures

OBJECTIVE

To evaluate outcomes of robotic-assisted transplant ureteral repair (RATUR) for the management of kidney transplant ureteral strictures (TUS).

METHODS

We retrospectively analyzed 41 consecutive patients who underwent RATUR for TUS at multiple tertiary referral centers between January 2016 and December 2022. RATUR was performed utilizing a robotic-assisted transperitoneal approach. The primary outcome was stricture recurrence rate and secondary outcomes included postoperative complicate rate, determining factors impacting with allograft functional recovery, and rate of conversion to open surgery. Categorical and continuous variables are displayed as total number (Percentage) or median [Interquartile Range], respectively. Pearson correlation coefficient was utilized to assess categorical variable correlation with creatinine.

RESULTS

The median age was 56years [44,66]. The female-to-male ratio was 1.1:1. Approximately 66% of patients were dialysis-dependent prior to kidney transplantation. TUS was identified at a median time of 4months [2, 15.5] following kidney transplant. Median stricture length was 2 cm [1.22, 2.9 cm]. There were no TUS recurrences with a median follow-up of 36months [24,48]. There were 3 Clavien grade 2 and 1 Clavien grade 3 complications (9.5%). No baseline characteristics or preoperative diagnostics were correlated with a long-term decline in renal allograft function.

CONCLUSION

RATUR has excellent and durable outcomes with low complication rates. These findings encourage the use of a minimally invasive definitive repair as a first-line treatment option for the management of TUS.

Inferior polar nephrectomy and vesicocalicostomy for complete ureteric stricture following antibody-mediated rejection in ABO-incompatible living donor kidney transplant: a report of a rare case

Renal transplant recipients are prone to urological complications, the most common of which is stricture of the transplant ureter. We present a rare case of complete ureteric stricture in a 37-year-old man who had undergone spousal living donor kidney transplantation with ABO incompatibility. Initially, treatment involved creating an anastomosis between the native right ureter and the renal pelvis of the transplanted kidney. However, the stricture recurred. Subsequently, the patient was successfully treated with inferior polar nephrectomy and vesicocalicostomy, which entailed anastomosing the lower calyx of the transplanted kidney to the bladder. After 7 months of follow-up, the patient continued to exhibit stable renal function without stricture recurrence.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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.

Recipient and renal allograft survival following living related-donor transplantation: a single center experience

Background

Despite improvements in surgical techniques of renal transplantation, still surgical complications remain a big challenge that might affect the post-transplant recipient and graft outcome. The aim of the current study was to retrospectively assess the surgical complications following living related kidney transplants in our center from 1990 to 2012 and determine their impact on long term recipient and graft survival.

Methods

We conducted a retrospective study of all live related-donor kidney transplants performed at our tertiary referral center between June 1990 and December 2012. Data regarding recipient demographics, details of surgical techniques, any reported complications and cumulative recipient and graft survival was analyzed.

Results

One hundred and four patients were included in the study whom we had access to their complete hospital records and they didn’t miss follow up. There were 41 surgical complications reported in 37 recipients, prevalence of 35.5%. Vascular and urologic complications were reported in 17(16.3%) and 11 (10.5%) recipients respectively. Lymphocele was post-operatively diagnosed in nine (8.7%) recipients. Recipient survival at 1 year and 5-year were 100% and 97% respectively. Graft survival at 1 year and at 5 years were 96% and 85.5% respectively. Surgical complications mentioned, other than renal artery thrombosis, had no statistically significant impact on the graft and recipient survival.

Conclusion

Although surgical complications post-transplantation are not rare, the resulting morbidity can be minimized by prompt management of complications. In general, the existence of surgical complications did not impact recipient or graft survival.

Retrograde ureteric stent insertion from percutaneous suprapubic access to the bladder in renal transplant recipients with ureteric stenosis: a novel minimally invasive technique

Background

Ureteric stricture is a common and salvaging complications after renal transplantation. Two treatment methods are usually used, retrograde ureteral stent placement and percutaneous nephrostomy. The former has a higher failure rate, the latter has a great risk. Therefore, a safe and reliable treatment is needed.

Case presentation

A technique of retrograde insertion of ureteral stent was established, which was applicable in three transplant recipients with post-transplant ureteral stenosis, and the data was retrospectively recorded. The patients are 2 men and 1 woman, ages 44, 27 and 32 years. These patients underwent a total of five times of retrograde insertion of ureteral stent between 2018 and 2019. None of these patients had any postoperative complication, but all patients had complete recovery from oliguric status within two weeks.

Conclusions

The retrograde ureteric stent insertion by percutaneous suprapubic access to the bladder (RUS-PSAB) was demonstrated feasibility and safety in a case series with short-term follow-up. However, larger prospective studies are needed.

Risk Factors for Anastomosis Leakage After Kidney Transplantation

Purpose

Kidney transplantation is one of the best treatment options for end-stage renal disease with an incidence of urologic complications of 2.5 to 30%. One of the most serious and frequent urological complications is urinary leakage from ureteroneocystostomy anastomosis. The purpose of this study was to evaluate risk factors of urinary leakage from ureteroneocystostomy anastomosis after kidney transplantation.

Patients and Methods

A retrospective study was performed on patients who received kidney transplantation and were diagnosed with urinary leakage thereafter based on renal scan or drain creatinine per serum creatinine compared with patients in control group. Risk factor assessment was based on inpatient and outpatient information from hospital database.

Results

From 459 patients who received kidney transplantation in 2016-2018, there were 20 patients who were diagnosed with urinary leakage after they underwent ureteroneocystostomy anastomosis. The significant risk factors for anastomosis leakage were size of suture materials and duration of ureteral stent insertion. No statistically significant difference in other factors such as underlying disease, surgical technique or duration of urinary catheter was found. About overall urological complication, gender and body mass index significantly affected the outcome.

Conclusion

The rate of urinary leakage complications was found to be about 4.36%. The risk factors of overall complication comprised gender and body mass index. Although a lot of previous studies revealed many risk factors that could affect urinary leakage, size of suture materials and duration of ureteral stent insertion were the significant risk factors in our study. Proper consideration should be given to the size of suture materials and optimal duration of ureteral stent.

Comparison of tandem ureteral stents, cryoplasty, and cutting balloon ureteroplasty in treatment of refractory transplant ureteral strictures

The objective of study was to compare clinical outcome of cryoplasty, tandem stents, and cutting balloon ureteroplasty as "bailout procedures" to prevent surgical intervention or stent dependency in renal transplant patients with refractory ureteral stricture. All patients who underwent a bailout procedure from June 11, 2003, to August 8, 2015, at a single institution were reviewed retrospectively. Refractory ureteral stricture was defined as ureteral stenosis not responding to at least two prior percutaneous plain balloon ureteroplasties. Primary patency was defined as stable allograft function following the procedure with unobstructed urine outflow, not requiring indwelling ureteral stent, repeat ureteroplasty, or surgical revision. Sixty-one procedures were performed on 51 patients. Patients were followed up for a median of 286 days. Overall primary patency rate was 26.1%. Primary patency rate by method was 38.1%, 23.1%, and 14.3% after cryoplasty, tandem stent placement, and cutting balloon dilatation, respectively (P = .260). Primary patency rate was higher in early (<3 months post-transplant) ureteral strictures (35.7% vs 13.3%; P = .047). More complications identified in patients who had tandem ureteral stents (P = .00754). As some renal transplant patients may not be good operative candidates for ureteral revision, it would be reasonable to attempt one of these "bailout" interventions as long as the clinical team and patient are aware of overall low potential for achieving primary patency.

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.

Tubular Ectasia in Renal Allograft Biopsy: Associations With Occult Obstructive Urological Complications

BACKGROUND

Urological obstructive complications (UOC) affect up to 15% of kidney transplants (KTX). Most cases are excluded by ultrasonography (US); however, accuracy may be limited in the early transplant phase. Features of acute tubular injury (ATI) in KTX biopsy may be informative but histological features indicating UOC are ill defined. Tubular ectasia (TE) was shown to be associated with UOC in experimental data. We evaluated the association of histomorphological features, particularly TE, with occult (=without relevant hydronephrosis in US) UOC and renal outcomes.

METHODS

We included all recipients with an early indication biopsy (976 of 1537 consecutive KTX). The biopsy finding of TE classified as "suspicious of UOC" was compared with the following endpoints: delayed graft function, estimated glomerular filtration rate, and occult UOC. Additionally, histopathological features of ATI were reevaluated by a single pathologist to increase diagnostic accuracy.

RESULTS

Fifty-eight (5.9%) patients presented with TE, which was not related to delayed graft function or estimated glomerular filtration rate. Forty percent of patients had a UOC (most frequently ureteral stenosis) close to biopsy. Comparing these biopsies to matched controls, TE was significantly associated with UOC (odds ratio 2.69; P = 0.018). After histopathological reevaluation of these biopsies including additional features of ATI, we developed a final multivariate model with a highly significant relationship to UOC (Receiver operating characteristic-area under the curve: 0.77; P = 0.001). The model provides a specificity of 78% and negative predictive value of 73%.

CONCLUSIONS

TE together with additional signs of ATI indicates occult UOC. This histological phenotype should trigger more detailed evaluation for UOC when there is no evidence of relevant hydronephrosis in the ultrasonography.

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.

Endoscopic Balloon Dilatation in the Treatment of Benign Ureteral Strictures: A Meta-Analysis and Systematic Review

BACKGROUND AND PURPOSE

Although balloon dilatation is one of the main endoscopic procedures used to treat benign ureteral strictures, its precise efficacy remains controversial. We aimed to identify, combine, and analyze existing published data to ascertain the efficacy of endoscopic balloon dilatation for benign ureteral strictures.

METHODS

In December 2018, a literature search was performed using Medline, Embase, and Web of Science databases. We included reports in which the study population consisted of patients who underwent endoscopic balloon dilatation for the treatment of benign ureteral strictures. Technical, short-term, and long-term success rates (expressed as mean ± standard error) were adopted as the outcome measures.

RESULTS

Using our search strategy, a total of 19 studies (all series reports) were included for analysis. Using a random-effects model, the pooled technical success rate of endoscopic balloon dilatation for benign ureteral strictures was found to be 89% ± 4%. Furthermore, the short-term success rate (i.e., 3 months after surgery) was 60% ± 10%, and the long-term success rate (i.e., 6-12 months after surgery) was 54% ± 14%. In the subgroup analysis, the success rate of endoscopic balloon dilatation for ≤2-cm benign ureteral strictures was significantly higher than that for >2-cm ones (odds ratio [OR]: 0.13; 95% confidence interval [CI]: 0.05-0.35). In addition, the success rate in cases with strictures of onset timing ≤3 months was relatively higher than that in cases with strictures of onset timing >3 months (OR: 0.46; 95% CI: 0.15-1.43).

CONCLUSION

Our study indicates that endoscopic balloon dilatation has a high success rate in the treatment of benign ureteral strictures with length ≤2 cm and onset timing ≤3 months. However, there is still no consensus on balloon type, dilatation pressure, expansion number, postoperative ureteral stent type, and stent retention time for the balloon dilatation technique.

Minimally Invasive Approach to Ureteral Stricture in Transplant Kidney by Periodic Retrograde Ureteral Stent Placement and Exchange

PURPOSE

The aim of the study was to evaluate the effectiveness of minimally invasive treatment of ureteral strictures and describe the technique that we used for retrograde placement of ureteral stent in transplant kidneys.

MATERIAL AND METHODS

We reviewed the medical cards of all transplant kidney patients with persistent ureteral strictures who were managed with periodical ureteral stent placement and balloon dilatation between 2008 and 2016. Different maneuvers that were used to overcome the difficulties for retrograde ureteral stent placement and exchange were discussed. Clinical characteristics and treatment outcomes of the study cohort were analyzed.

RESULTS

Between 2008 and 2016, a total of 1026 transplantations were performed in our clinic, and ureteral stricture was found in 13 patients (1.26%). Of the 13 patients, 8 were treated with periodic ureteral stent insertion and balloon dilatation. Ureteral stent insertion or stent exchange was performed in 52 transplant renal units. The overall success rate of retrograde ureteral stent insertion at the first attempt was 75% and stent exchange success rate was 100%. Renal function remained stable in all patients during a median follow-up of 41 months (range, 13-60 months). No other local or systemic complication was encountered and no stent encrustation was noted.

CONCLUSIONS

Endoscopic management of ureteral stricture by periodical retrograde ureteral stent replacement and balloon dilatation is safe, effective, and highly successful in transplant patients who are not eligible for open reconstructive surgery.

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.

Minimally invasive approach for the management of urological complications after renal transplantation: single center experience

BACKGROUND

The aim of the study was to characterise urological complications after renal transplantation and to evaluate the role of minimally invasive management for urological complications.

METHODS

A total of 920 kidney transplantations were performed between 2008 and 2015. All patients were followed up for at least 1 year after transplantation. Complications regarded as urological were urinary leakage, ureteral stricture, urinary malignancy, bladder outlet obstruction (BOO) and urinary calculi. We evaluated data from the time of occurrence of urological complications and the type of the management prescribed.

RESULTS

Among 920 transplantations performed in our clinic, 41 (4.4%) urological complications arose. Twenty (48.8%) of the complications occurred during the first 3 months and 21 (51.2%) occurred after 3 months, postoperatively. Ureteral strictures were found in 14 (34.1%) patients, urinary tract stones in seven (17%), BOO in 6 (14.6%) and urinary leakage was observed in 5 (12.1%) patients. Ureteral stricture was managed with endoscopic approach in eight (61.3%) patients. Urinary tract stones and urinary leakage were managed in 7 (100%) and 4 (75%) patients with endoscopic approach. Overall 29 (70.7%) of 41 urological complications were managed with endourological approaches.

CONCLUSIONS

It is likely that the importance of open surgery could decrease in the future. Endoscopic management of urological complications have come to have an important role in the treatment of urological complications after transplantation.

Transplant Kidney Retrograde Ureteral Stent Placement and Exchange: Overcoming the Challenge

OBJECTIVE

To present a reliable technique for fluoroscopic controlled, large-bore, ureteral stent placement and exchange in transplant kidneys with persistent ureterovesical strictures.

MATERIALS AND METHODS

We reviewed the medical charts of all patients who underwent kidney transplant with persistent ureterovesical strictures who underwent ureteral stent placement or exchange at our institution between 2005 and 2015 using the new technique. Clinical characteristics and treatment outcomes of the study cohort were analyzed.

RESULTS

Ureteral stent insertion or stent exchange, using this technique, was performed in 32 renal transplant units. Median operating time was 24 minutes (interquartile range, 21-36.75 minutes). The overall success rate of the technique at first attempt was 96.9%. In 1 patient, drainage of the transplanted kidney with a nephrostomy tube was indicated after procedure failure. No other local or systemic complications were encountered, and no stent encrustation was noted in this cohort of patients. Renal function remained stable in all patients during a median follow-up of 59 months (interquartile range, 28-61 months).

CONCLUSION

Herein, we present in detail a step-by-step technique for the insertion and exchange of large-bore ureteral stents in transplanted kidneys. The technique was shown to be safe, effective, and highly successful.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Open Vesicocalicostomy for the Management of Transplant Ureteral Stricture

A 59-year-old male developed a proximal stricture of his transplant ureter ten years after a living donor renal transplant. Endoscopic management was unsuccessful, and the patient was temporized with percutaneous nephrostomy tubes for months. Eventually, it became clear he would require surgical revision. Intraoperatively, complete fibrosis of the renal hilum, and intrarenal location of the pelvis precluded the planned pyelovesicostomy. A successful open vesicocalicostomy was performed, anastomosing a bladder flap to a lower pole calix. The patient remains recurrence free after 6 months of follow-up.

Ureteral Complications in Kidney Transplantation: Analysis and Management of 853 Consecutive Laparoscopic Living-Donor Nephrectomies in a Single Center

BACKGROUND

We report the incidence and nature of ureteral and surgical complications in our series of 853 consecutive living-donor renal transplants after laparoscopic living-donor nephrectomy. The aim of this study was to analyze the therapeutic approaches to ureteral complications in kidney transplantations and their relationship with recipient outcome.

METHODS

The medical records of patients who underwent kidney transplantation from 2000 to 2014 were reviewed retrospectively. After the donor nephrectomies were performed with the use of laparoscopic, hand-assisted laparoscopic, and vesico-ureteral anastomosis, the recipient's ureteral complications were classified according to the mechanism and site of urinary tract involvement: anastomosis stricture, anastomosis leakage, vesico-ureteral reflux, and urolithiasis.

RESULTS

Among the 853 cases of kidney transplantation, ureteral complications occurred in 66 patients (7.73%). The most common complication was urinary tract infection caused by vesico-ureteral reflux (n = 24, 2.81%), which was managed with by means of sub-ureteral polydimethylsiloxane injection. The second most common complication was the anastomosis site stricture (n = 23, 2.69%), which was treated by means of ureteral re-implantation or percutaneous nephrostomy. Anastomosis site leakage occurred in 11 patients (1.28%) and was managed by percutaneous nephrostomy with double-J stenting and drainage or ureteral re-implantation. Urolithiasis occurred in 8 patients (0.93%).

CONCLUSIONS

There was an 8% rate of recipient ureteral complications at our institution. Of the 66 patients, 46 (5.4%) required surgical repair. The remaining 20 patients with ureteral complications were treated with conservative care or minimally invasive procedures. The keys to successful management of these problems are early diagnosis and prompt reconstruction whenever possible. Most ureteral complications are easily managed with a successful outcome with early intervention.

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.

Internal or External Stenting of the Ureterovesical Anastomosis in Renal Transplantation

BACKGROUND

Stenting of the ureterovesical anastomosis reduces the incidence of urological complications (UCs) after renal transplantation, but there are multiple stenting techniques, and there is no consensus regarding which technique is preferred. The aim of this study was to compare an internal versus an external stenting technique on the incidence of UCs.

METHODS

This is a retrospective analysis of 419 deceased donor renal transplantations performed between January 2008 and December 2013. Until 2011, 183 patients received an external stent through the ureterovesical anastomosis placed by suprapubic bladder puncture (SP stent). From 2011, 236 recipients received an internal double-J (JJ) stent.

RESULTS

The rate of UC was 3.8% in JJ stents, compared to 9.3% in SP stents (p = 0.021). No difference in surgical ureter revision rate was observed between the groups (2.1 vs. 5.5%; p = 0.068). Urinary tract infection (UTI) rate and graft function were comparable between both groups.

CONCLUSIONS

Internal JJ stenting significantly decreased the incidence of UC compared to an external SP stent. There was no difference in surgical ureter revision rate, UTI or graft function.

[Management of urological complications after renal transplantation]

Urological complications after kidney transplantation can cause a major reduction in renal function. Surgical complications like urinary leakage and ureteral obstruction need to be solved by a specialist in the field of endourological procedures and open surgical interventions. The article summarizes this and other common urological problems after kidney transplantation.

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.

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.

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.

Ureteral strictures revisited…trying to see the light at the end of the tunnel: a comprehensive review

A ureteral stricture is a rather rare urological event defined as a narrowing of the ureter causing a functional obstruction and renal failure, if left untreated. The aim of this review article is to summarize and discuss current knowledge on the incidence, pathogenesis, management, and follow up of proximal, mid, and distal ureteral strictures.

Ultrasonographic evaluation of the renal transplant

Ultrasonography is an excellent tool for evaluation of the renal transplant in the immediate postoperative period and for long-term follow-up. In this article, normal imaging findings and complications of renal transplantations are described. Disease processes are divided into vascular, perinephric, urologic and collecting system, and parenchymal abnormalities. Attention is paid to the time of occurrence of each complication, classic imaging findings, and potential pitfalls.

Independent risk factors for urological complications after deceased donor kidney transplantation

Urological complications after kidney transplantation are mostly related to the ureteroneocystostomy, often requiring interventions with additional costs, morbidity and mortality. Our aim was to assess risk factors for urological complications in deceased donor kidney transplantation. Between January 2000 and December 2011, 566 kidney transplantations were performed with deceased donor kidneys. Recipients were divided in a group with, and a group without urological complications, defined as the need for a percutaneous nephrostomy catheter or surgical revision of the ureteroneocystostomy. Univariate and multivariate analyses were performed. Univariate analysis showed increased number of male donors (p = 0.041), male recipients (p = 0.002), pre-emptively transplanted recipients (p = 0.007), and arterial reconstructions (p = 0.004) in the group with urological complications. Less urological complications occurred in recipients on hemodialysis (p = 0.005). More overall surgical interventions (p<0.001), surgical site infections (p = 0.042), urinary tract infections (p<0.001) and lymphoceles (p<0.001) occurred in the group with urological complications. Multivariate analysis showed that male recipients (p = 0.010) and arterial reconstructions (p = 0.019) were independent risk factors. No difference was found between both groups in patient or graft survival. In conclusion, recipient male gender and arterial reconstruction are independent risk factors for urological complications after deceased donor kidney transplantation. Nevertheless, graft and recipient survival is not different between both groups.

Urinary fistula repair in a renal graft through a partial nephrectomy and omentoplasty

OBJECTIVES

We present the management with partial nephrectomy and interposition of the greater omentum in case of urinary fistulas in renal allograft.

MATERIAL AND METHOD

We present a patient with necrosis at the inferior pole of the renal graft that affected calyceal system but with pyeloureteral vascularization preserved. The patient's condition was satisfactorily managed with a partial nephrectomy of the necrotic renal segment and primary suturing of the collecting system with interposition of the greater omentum. We reviewed the cases published to date of partial nephrectomy in renal allograft, and examined their outcomes by analyzing the patient presentation, diagnostic tools, and surgical techniques used.

RESULTS

There are few cases in the current literature that describe conservative surgical management of urinary fistulas caused by segmental necrosis after renal transplantation. Surgical approach using partial nephrectomy in these cases produces favorable outcomes in our experience and reported cases.

CONCLUSIONS

Despite its obvious surgical complexity, this nephron-sparing management is feasible and should be implemented in cases where the prior renal function and the quantity of healthy parenchyma indicate a favorable subsequent evolution for the renal graft.

Laparoscopic ureteral reimplantation in a renal transplant

We present what is to our knowledge, the first case of laparoscopic ureteral reimplantation reported in the renal transplant.

The ureteral stenosis is one of the most difficult renal transplant complications to deal with. With the development of the endourological approach, this treatment has become the first treatment option for these patients. The patient is a 28-year-old female who received a renal allograft from a cadaver donor in 2008. Ureteral stenosis was diagnosed.

The laparoscopic approach seems to be a good option over the open approach, with the benefits related with laparoscopic surgery.

Retrograde endoureterotomy for persistent ureterovesical anastomotic strictures in renal transplant kidneys after failed antegrade balloon dilation

OBJECTIVE

To evaluate the long-term outcomes and complications of retrograde endoureterotomy for persistent ureterovesical anastomotic strictures in renal transplant patients after percutaneous balloon dilation failure.

METHODS

From January 2000 to May 2010, 26 (2.6%) of 1004 renal transplant patients developed ureterovesical anastomotic stricture after surgery. Seven of these patients and five additional referred patients with similar characteristics were treated with retrograde endoureterotomy after ≥1 previous unsuccessful attempt at percutaneous balloon dilation. All strictures treated were <1 cm in length. The clinical characteristics and outcomes were analyzed. Success was defined as the absence of symptoms and the resolution of obstruction on imaging after the procedure.

RESULTS

The median interval from initial treatment to endoureterotomy was 2.9 months (range 1.3-62.1). Before endoscopic treatment, 8 patients (67%) were treated with a single trial of balloon dilation and 4 (33%) with multiple trials. Endoureterotomy was performed using cold knife, holmium:yttrium-aluminum-garnet laser, and Bugbee electrode in 9, 2, and 1 patients, respectively. The median follow-up period was 44.4 months (range 2.4-68.6). Recurrent stricture developed in 2 patients during a mean follow-up of 4.7 months. Thus, the overall success rate was 83%. Postoperative complications appeared in 3 patients (25%) with culture-positive urinary tract infection. One graft failure occurred but was not related to a recurrent stricture.

CONCLUSION

After failure of antegrade percutaneous balloon dilation, retrograde endoureterotomy is an effective salvage procedure for well-selected cases of renal transplant patients with a short ureterovesical anastomotic stricture.

Impact of surgeon experience on complication rates and functional outcomes of 484 deceased donor renal transplants: a single-centre retrospective study

OBJECTIVE

To determine how postoperative and functional outcomes after deceased donor renal transplantation (DDRT) are related to surgeon experience.

PATIENTS AND METHODS

The outcomes of 484 adult DDRT performed by 13 urological surgeons were retrospectively reviewed. After completion of a staged renal transplant training programme under supervision of an attending urological transplant surgeon, the 13 surgeons were either assigned to the inexperienced group (n = 8) or the experienced group (n = 5). Surgeons in the experienced group had performed more than 30 unsupervised DDRT in a standard fashion with routine ureteric stenting. Between 1988 and 2005, inexperienced surgeons performed 152 DDRT, whereas experienced surgeons performed 332 DDRT.

RESULTS

Patient and graft survival at 2 hyears were 98% and 94.7%, respectively. Early graft loss in five recipients was unrelated to surgeon experience. Delayed graft function occurred in 29% of cases and median 1-year serum-creatinine was 1.48 mg/dL, with no difference between surgeon groups. Postoperative bleeding and lymphocele formation were the most frequent surgical complications, with an equal distribution between groups. Ureteric complications had a significantly higher incidence among inexperienced surgeons (6.6% versus 2.7%; P = 0.04).

CONCLUSION

We conclude that DDRT as performed by inexperienced urological renal transplant surgeons has both acceptable short- and long-term outcomes.

Renal transplant lithiasis: analysis of our series and review of the literature

BACKGROUND AND PURPOSE

Renal transplant lithiasis represents a rather uncommon complication. Even rare, it can result in significant morbidity and a devastating loss of renal function if obstruction occurs. We present our experience with graft lithiasis in our series of renal transplantations and review the literature regarding the epidemiology, pathophysiology, and current therapeutic strategies in the management of renal transplant lithiasis.

PATIENTS AND METHODS

In a retrospective analysis of a consecutive series of 1525 renal transplantations that were performed between January 1983 and March 2007, 7 patients were found to have allograft lithiasis. In five cases, the calculi were localized in the renal unit, and in two cases, in the ureter. A review in the English language was also performed of the Medline and PubMed databases using the keywords renal transplant lithiasis, donor-gifted lithiasis, and urological complications after kidney transplantation. Several retrospective studies regarding the incidence, etiology, as well as predisposing factors for graft lithiasis were reviewed. Data regarding the current therapeutic strategies for graft lithiasis were also evaluated, and outcomes were compared with the results of our series.

RESULTS

Most studies report a renal transplant lithiasis incidence of 0.4% to 1%. In our series, incidence of graft lithiasis was 0.46% (n=7). Of the seven patients, three were treated via percutaneous nephrolithotripsy (PCNL); in three patients, shockwave lithotripsy (SWL) was performed; and in a single case, spontaneous passage of a urinary calculus was observed. All patients are currently stone free but still remain under close urologic surveillance.

CONCLUSION

Renal transplant lithiasis requires vigilance, a high index of suspicion, prompt recognition, and management. Treatment protocols should mimic those for solitary kidneys. Minimally invasive techniques are available to remove graft calculi. Long-term follow-up is essential to determine the outcome, as well as to prevent recurrence.

Use of stenting in living donor kidney transplantation: does it reduce vesicoureteral complications?

The risk of urologic complications after kidney transplantation is 0% to 30%. We studied the impact of prophylactic stent placement during transplantation by assessing the necessity for a percutaneous nephrostomy (PCN) after living kidney transplantation. From January 2003 to December 2007, 342 living donor kidney transplantations were performed. Intra- and postoperative data were collected retrospectively from 285 patients with stent and 57 without. Baseline characteristics were not significantly different between groups, except for the number of previous transplantations: 31 (11%) patients with versus 16 (28%) without stent had a history of >1 transplantation (P < .001). From patients with PCN, 55 (87%) patients in the stented group received a PCN <3 months versus 11 (100%) in the nonstented group (P = .71). The reoperation rate for urologic complications was similar in both groups (3% (stented) versus 5% (nonstented; P = .43). In multivariate analysis, risk for PCN was similar in both groups (odds ratio 1.21, 95% confidence interval 0.5-2.5). Recipient survival was not significantly different. One- and 3-year death-censored graft survival was not significantly different between stented (89% and 84%) and nonstented group (90% and 85%, P = .71 and P = .96). Ureteral stent insertion is not associated with a reduced rate of PCN placement in living donor kidney transplantation.

Percutaneous management of ureteral stenosis of transplanted kidney: technical and clinical aspects

In the field of renal transplantation, advances in the management of graft rejection have led to improved graft and patient survival rates, however other types of complications have now become more apparent, e.g. vascular or urological. The most common urological complications following renal transplantation are ureteral stenosis or obstruction, constituting a significant problem of the renal graft's survival. The most important aspects concerning these complications are early diagnosis and prompt treatment since any delay in their management may lead to renal graft dysfunction or even graft loss. Developments in interventional radiology have provided minimally invasive means to treat urological complications with low complication rates. Herein we review the literature in order to evaluate the efficacy of percutaneous management of ureteral stenosis regarding its safety, immediate and long-term results, complications as well as rate of recurrence.