Urologic considerations and complications in kidney transplant recipients

Ex Vivo Surgical Removal Versus Conservative Management of Small Asymptomatic Kidney Stones in Living Donors and Long-term Kidney Transplant Outcomes

BACKGROUND

Donors with small asymptomatic kidney stones have been increasingly accepted because of organ shortages and advances in endoscopic urology. This study aims to evaluate and compare long-term living-donor kidney transplant outcomes following ex vivo surgical removal versus conservative management of donors' gifted asymptomatic stones.

METHODS

Between January 2007 and December 2021, 119 kidney transplant recipients received stone-bearing kidneys, divided into the removal group (N = 63) and observation group (N = 56). We evaluated posttransplant stone events, urinary infections, kidney function, delayed graft function, length of hospital stay, and survival outcomes.

RESULTS

After a median follow-up of 75.5 mo, the removal group had a 10.9% lower absolute incidence of stone events (7/56 [12.5%] versus 1/63 [1.6%]; hazard ratio, 0.08; 95% confidence interval, 0.01-0.77) and a 14.3% lower absolute incidence of urinary infections (16/56 [28.6%] versus 9/63 [14.3%]; hazard ratio, 0.42; 95% confidence interval, 0.19-0.95) than the observation group. The removal group also showed superior kidney graft function. The 2 groups had comparable length of hospital stay (11.0 versus 12.0 d; P  = 0.297) and exhibited similar delayed graft function incidence (1/56 [1.8%] versus 2/63 [3.2%]; P  = 1.000) and urinary stricture incidence (1/56 [1.8%] versus 3/63 [4.8%]; P  = 0.621). Graft survival ( P  = 0.350) and patient survival ( P  = 0.260) were comparable between 2 groups. Subgroup analyses in recipients who received kidneys with stones <4 mm also reported similar results.

CONCLUSIONS

Ex vivo surgical removal might outperform conservative management for donors' gifted asymptomatic kidney stones, improving long-term transplant outcomes and reducing stone events without increasing perioperative complications, even for stones <4 mm.

Robotic-Assisted Management of Ureteral Complications in Post-Renal Transplant Patients: A Case Series and Literature Review

Introduction: Urologic complications are thought to be the most common surgical complication of renal transplantation. Ureteral pathology, including stenosis, urine leak, and vesicoureteral reflux, predominates. Although endourologic and interventional radiological management may be utilized, failure rates remain relatively high and surgical reconstruction remains the definitive management. Robotic ureteral reconstruction has been demonstrated to provide patient benefit in nontransplant populations, but the literature on transplant reconstruction is very limited. This study reports an additional series of patients with a focus on surgical technique, as well as reviews the available evidence for robotic reconstruction for post-transplant ureteral complications. Methods: All institutional patients undergoing robotic-assisted reconstruction for post-transplant ureteral complications for the years 2019-2022 were included. Intra- and postoperative variables, patient demographics, and follow-up data were obtained retrospectively from parsing of patient records. Statistics were tabulated descriptively. Results: Eleven patients underwent ureteral reconstruction. Of the 11, 9 (81%) were male with a mean age of 51.9 years (16-70) and BMI of 33.8 (24.3-49.1). The most common (10/11) indication for reconstruction was stricture; the most common (10/11) technique used was Lich-Gregoir reimplantation. Mean operative time was 288 minutes (143-500). There were no intra- or immediate postoperative complications. Median length of stay was 2 days (1-22). There were two incidences of mortality at 2 and 5 months postoperatively unrelated to surgery. There were four readmissions within 30 days, three for urinary tract infection (UTI) and one for a pelvic abscess which required washout. The remainder of the cohort has been followed for a mean of 14.6 months (6-41) without any incidences of graft loss or recurrence of ureteral pathology. Conclusions: Robotic-assisted ureteral reconstruction is a technically challenging but highly feasible technique that may provide the benefits of minimally invasive surgery while still allowing definitive reconstruction. Centers with extensive robotic capabilities should consider the technique.

Impact of early surgical complications on kidney transplant outcomes

BACKGROUND

Kidney transplantation (KT) improves clinical outcomes of patients with end stage renal disease. Little has been reported on the impact of early post-operative surgical complications (SC) on long-term clinical outcomes following KT. We sought to determine the impact of vascular complications, urological complications, surgical site complications, and peri-graft collections within 30 days of transplantation on patient survival, graft function, and hospital readmissions.

METHODS

We conducted a single-centre, observational cohort study examining adult patients (≥ 18 years) who received a kidney transplant from living and deceased donors between January 1st, 2005 and December 31st, 2015 with follow-up until December 31st, 2016 (n = 1,334). Univariable and multivariable analyses were performed with Cox proportional hazards models to analyze the outcomes of SC in the early post-operative period after KT.

RESULTS

The cumulative probability of SC within 30 days of transplant was 25%, the most common SC being peri-graft collections (66.8%). Multivariable analyses showed significant relationships between Clavien Grade 1 SC and death with graft function (HR 1.78 [95% CI: 1.11, 2.86]), and between Clavien Grades 3 to 4 and hospital readmissions (HR 1.95 [95% CI: 1.37, 2.77]).

CONCLUSIONS

Early SC following KT are common and have a significant influence on long-term patient outcomes.

An unusual ureteral dynamic obstruction in a kidney transplant patient

INTRODUCTION

Ureteral complications are common in kidney transplanted patients; approximately 2.6-15% of patients develop ureteral obstruction/stenosis at some time after surgery, which is one of the most frequent urologic complications. Inguinal herniation of the neoureter is a rare complication but it must be taken into account.

CLINICAL REPORT

We describe the case of a 78-years old male kidney transplanted patient (2004), who was admitted at the emergency room due to abdominal pain and with evidence of acute kidney injury. The ultrasound showed hydronephrosis (grade III) along with ureteral dilatation which ended with an image compatible with a kinking, that was confirmed at the TC and showed that the kneeling was in the right inguinal canal. It was possible, with a manual hernia reduction manoeuvre, to readjust the kneeling of the neoureter resolving the condition temporarily. The patient underwent underwent surgical hernia repair with no complication and complete recovery of renal function.

CONCLUSIONS

When ureter obstruction of the transplanted kidney occurs, it is crucial to resolve the obstruction as soon as possible in order to preserve kidney function. Hernioplastic is an effective way to treat ureter obstruction when it is caused by its herniation.

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.

Risk Factors for Urologic Complications After Kidney Transplantation and Impact in Graft Survival

Background and Purpose

Kidney transplantation (KT) is the best therapy for chronic kidney disease (CKD). Major urologic complications (MUCs) are the second etiology associated to morbidity and graft loss following KT, after rejection episodes. The objective of this study was to estimate the incidence, risk factors and impact on graft survival associated to urological complications in KT patients.

Patients and Methods

A retrospective cohort based on electronic patient files of kidney transplant recipients from Colombiana de Trasplantes was created for the period August 2008 to September 2019. Initiation of follow-up was defined as the date of transplantation up to 3 years post-transplantation. Incidence of ureteral stenosis, ureteral obstruction, and ureteral leak was measured. A logistic regression multivariate model was adjusted to determine the associated factors to MUCs (yes/no). Patient and graft survival time were analyzed using a Kaplan-Meier method.

Results

A total of 1584 KT patients were included in the cohort. MUCs were present in 195 (12.6%) KT patients. We found that dialysis duration (OR: 1.004; p = 0.02) remained significant for the incidence of MUCs in KT patients of deceased donors. Probability of graft and patient survival at 3 years of follow-up was 90.5% and 85.5%, respectively. No significant difference was found on graft and patient survival in KT patients with or without MUCs.

Conclusion

MUCs are frequent complications for KT. We did not observe significant differences in graft or patient survival according to the presence of MUCs. The identification of MUCs and risk factors may guide transplant teams for future surgical and clinical decisions.

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.

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.

Urine Leak From the Necrotic Lower Pole of a Transplanted Kidney: A Rare Complication in a Pediatric Deceased Donor Kidney Transplant Recipient

Kidney transplant patients are prone to a variety of complications, even for the most experienced surgical teams. Our busy transplant center recently performed its 5,000th solid organ transplant. We present the case of an 18-year-old male with end-stage renal disease who underwent a deceased donor kidney transplant. He developed a urine leak from the necrotic lower pole of his graft kidney and subsequently developed urosepsis and was admitted. Clinicians must have a high suspicion for complications in the immediate post-operative period in kidney transplant patients. In this report, we will highlight our diagnostic and treatment steps to preserve the patient's graft while addressing his rare complications.

Risk Factors, Diagnosis, and Treatment of Lymphocele After Renal Transplantation: A Retrospective Study

INTRODUCTION

Despite recent advances, lymphoceles are the most frequent complications following renal transplantation (RT), with an incidence of 0.6% to 51%. In this study, we present risk factors, treatments, and outcomes for lymphoceles after RT at our center.

MATERIAL AND METHODS

Since January 2018, 461 RTs were performed at our center. Nine recipients were excluded. The remaining 452 RTs were analyzed retrospectively. Recipients were divided into 2 groups: a lymphocele group (n = 29) and a nonlymphocele group (n = 423). Lymphoceles were diagnosed by ultrasound. Statistical analyses were made using the SPSS 15 software program.

RESULTS

Twenty-nine (6.4%) of the 452 recipients developed lymphoceles. Seven of these 29 (24.1%) recipients were asymptomatic. The most common symptom was hydronephrosis (34.4%). Percutaneous drainage was performed in 21 recipients; sclerotherapy with percutaneous drainage was used in the remaining 8. In 5 (17.2%) recipients, there was a recurrence of lymphoceles. There were significant differences with respect to age (50-65 years; P = .016), use of a drainage catheter (P = .044), and polycystic kidney diseases (P = .049).

CONCLUSION

Lymphoceles can be treated successfully using the percutaneous drainage technique alone or in combination with povidone iodine. Drainage use, polycystic kidney disease, and age (50-65 years) were established as risk factors for lymphocele development.

Hypothermic machine perfusion can safely prolong cold ischemia time in deceased donor kidney transplantation. A retrospective analysis on postoperative morbidity and graft function

In deceased donor kidney transplantation (KT), a prolonged cold ischemia time (CIT) is a negative prognostic factor for KT outcome, and the efficacy of hypothermic machine perfusion (HMP) in prolonging CIT without any additional hazard is highly debated. We conducted a retrospective study on a cohort of 154 single graft deceased donor KTs, in which a delayed HMP, after a preliminary period of static cold storage (SCS), was used to prolong CIT for logistic reasons. Primary outcomes were postoperative complications as well as 1 year graft survival and function. 73 cases (47.4%) were managed with HMP and planned KT, while 81 (52.6%) with SCS and urgent KT. The median CIT in HMP group and SCS group was 29 hour:57 minutes [27-31 hour:45 minutes] and 11 hour:25 minutes [9-14 hour:30 minutes], respectively (P < .001). The period of SCS in the HMP group was significantly shorter than in the SCS group (10 vs. 11 hour:25 minutes, P = .02) as well as the prevalence of expanded criteria donors was significantly higher (43.8% vs. 18.5%, P < .01). After propensity score matching for these two baseline characteristics, the HMP and SCS groups showed comparable outcomes in terms of delayed graft function, vascular, and urologic complications, infections, and episodes of graft rejection. At 1 year follow-up, serum creatinine levels were comparable between the groups. Therefore, the use of HMP to prolong the CIT and convert KT into a planned procedure seemed to have an adequate safety profile, with outcomes comparable to KT managed as an urgent procedure and a CIT nearly three time shorter.

The Double-Edged Sword of Immunosuppressive Therapy in Kidney Transplantation: A Rare Case Report of Pulmonary Mucormycosis Post-Transplant and Literature Review

Immunosuppressive therapy is improving the graft survival of kidney transplant recipients and increasing the potential risk of infection. Pulmonary mucormycosis is a rare post-operative infection complication characterized with rapid deterioration and high mortality. In this case, a 33-year-old patient underwent a kidney transplantation with regular immunosuppressive therapy. Soon, 38 days post-transplant, pulmonary patchy shadows can be seen in the radiological examination and rounded into a large cavity formation with splenic rupture 25 days later. The diagnosis of mucormycosis was confirmed by lung biopsy and spleen histopathology. This case is a reminder that early diagnosis is imperative, meanwhile, rational antifungal therapy, timely elimination of immunosuppressants, and alternatively, abandoning the graft should be prudently assessed in the treatment of mucormycosis.

Urologic complications after transplantation of 225 en bloc kidneys from small pediatric donors ≤20 kg: Incidence, management, and impact on graft survival

Pediatric en bloc kidney transplants (EBKs) from small deceased pediatric donors are associated with increased early graft loss and morbidity. Yet, urologic complications post-EBK and their potential impact on graft survival have not been systematically studied. We retrospectively studied urological complications requiring intervention for 225 EBKs performed at our center January 2005 to September 2017 from donors ≤20 kg into recipients ≥18 years. Overall ureteral complication incidence after EBK was 9.8% (n = 22) (12% vs 2% for EBK donors < 10 vs ≥ 10 kg, respectively [P = .031]). The most common post-EBK urologic complication was a stricture (55%), followed by urine leak (41%). In all, 95% of all urologic complications occurred early within 5 months posttransplant (median, 138 days). Urologic complications could be successfully managed nonoperatively in 50% of all cases and had no impact on graft or patient survival. In summary, urologic complications after EBK were common, associated with lower donor weights, occurred early posttransplant, and were often amenable to nonoperative treatment, without adversely affecting survival. We conclude that the higher urologic complication rate after EBK (1) should not prevent increased utilization of small pediatric donor en bloc kidneys for properly selected recipients, and (2) warrants specific discussion with EBK recipients during the preoperative consent process.

Uncommon Complications in the First Year After Renal Transplantation

INTRODUCTION

Classic post-transplant complications are highly studied and monitored; however, other unusual complications may occur due to immunosuppression. The objective of this study is to show these rare complications in a kidney transplant center.

MATERIAL AND METHODS

Retrospective, observational, longitudinal study of renal transplants carried out from 2013 to 2017 in the Renal Transplant Unit of the National Medical Center Siglo XXI. A total of 790 transplants were performed, with surveillance for 1 year and rare events described. An analysis of frequencies and percentages of the events was performed using the statistical package SPSS version 25.

RESULTS

Of the 790 patients, 110 (13.92%) experienced rare events, classified into 9 types of complications.

DISCUSSION AND CONCLUSIONS

Complications exist in renal transplantation that are often ignored or minimized. A considerable number have been observed in this study, 110 events (13.92%); this result allows us to consider multiple possibilities in a kidney transplant program, especially infectious complications (34 patients) and surgical complications (29 cases). With the increase in diabetic receptor transplantation, metabolic complications will surely increase in the coming years.

Nursing Care of the Patient With Neurogenic Bladder After Kidney Transplantation: A Case Report

OBJECTIVE

Urologic complications are among the most common complications after kidney transplantation. These complications are urinary retention, hematuria, hemorrhage, urinary leakage, vesicoureteral reflux, pyelonephritis, and nephrolithiasis. Although neurogenic bladder is one of the indications for kidney transplantation, it is not considered in the literature to be an expected complication after transplantation. In this case, we discuss the nursing care of a patient who underwent kidney transplantation from a living donor and developed neurogenic bladder.

CASE REPORT

A 60-year-old woman underwent kidney transplantation from a living donor, and neurogenic bladder developed in the patient 1 year after kidney transplantation. Clear intermittent catheterization treatment was administered for the kidney transplant recipient with neurogenic bladder. Clear intermittent catheterization treatment was stopped in the patient who had frequent urinary tract infections and, alternatively, sacral neuromodulation treatment was administered to the patient.

CONCLUSIONS

The nursing care of a patient with neurogenic bladder after kidney transplantation aims to prevent excessive bladder distension, infection, stone formation, vesicoureteral reflux, renal failure, urinary tract damage, and incontinence, and to ensure regular and complete discharge of the bladder. The most common treatment modalities for these objectives are permanent or intermittent catheterization, sacral neuromodulation, and medical therapy. In the care of the patient with neurogenic bladder after kidney transplantation, nurses should provide appropriate care related to treatment options and bladder training, plan urination schedules of the patient, and monitor for possible complications.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

Tubular vesicopyelostomy for the management of types 2 and 3 (long-segment) ureteric stenosis after kidney transplantation

Late ureteral stenosis following kidney transplantation needs immediate correction in order to protect allograft function and requires a complicated surgical procedure. In this study, we present the long-term results of tubular bladder reconfiguration and cystopyelostomy (tubular vesicopyelostomy), an innovative and practical procedure for the management of long-segment ureteric stenosis (types 2 and 3) after transplantation. Between 2002 and 2017, 722 kidney transplant patients were monitored at the University of Medical Sciences, Bozyaka Organ Transplantation and Research Center. Twenty-eight of these patients underwent tubular vesicopyelostomy operation; 17 male and 11 female patients with a mean age of 45.6 ± 10.5 years. Time to surgical intervention for urinary tract obstruction was 122.5 ± 114.7 months. The mean serum creatinine values previous to and 3 days following the tubular vesicopyelostomy operation were 3.46 ± 1.5 mg/dL and 1.75 ± 0.7 mg/dL, respectively (p < 0.0001). Within a mean follow-up period of 55.1 ± 40.9 months, functional grafts were recorded in 22 patients with a mean serum creatinine value of 1.92 ± 0.8 mg/dL. Only one patient developed anastomotic stenosis after the tubular vesicopyelostomy procedure, giving an overall success rate for tubular vesicopyelostomy of 96.4%. Six patients returned to hemodialysis. In five, the underlying etiology was not related to recurrent obstruction or surgical complications. Sixteen patients underwent allograft biopsy after the operation, but features of tubulointerstitial nephritis were seen in only one. Tubular vesicopyelostomy operation is a safe and successful method for the surgical treatment of late and complicated ureteral obstructions with excellent long-term results. It may be a good, practical alternative to other more sophisticated surgical options.

Application of ureterorenoscope and flexible ureterorenoscope lithotripsy in removing calculus from extracorporeal living donor renal graft: a single-center experience

Here, we reported our clinical application of ureterorenoscope (URS) and flexible URS lithotripsy in stone removal on 10 cases of excised living donor kidney graft. After the extraction of donor kidney by retroperitoneal laparoscopy, the donor graft was perfused with 4 °C HCA solution. Calculus between 2–4 mm were removed intact with lithotomy forceps under direct vision of URS. Larger calculi of >4 mm were fractured with flexible URS combining holmium laser lithotripsy. Fragments of the calculus were extracted with basket extractor and lithotomy forceps. All operations were successful. The operation time was 14–31 min (average 21.2 ± 6.3 min). The kidneys were then transplanted to the recipients using routine procedure. The transplanted kidneys functioned well after transplantation. Gross hematuria resolved 1–4 d after operation (average 2.6 ± 0.9 d). The transplanted kidneys functioned well without early complications such as functional recovery delay and acute graft rejection. The donors and recipients were followed for 12 months. The size of the transplanted kidneys was normal and new stones or urinary obstruction was not seen upon urinary color Doppler ultrasound examination. In conclusion, we believe it is feasible, safe and effective to use URS or flexible URS combining holmium laser lithotripsy on extracorporeal living donor kidney.

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.

Differential Characteristics of Kidney Transplant Recipients According to 1-Year Chronic Kidney Disease Stage 3a and Stage 3b Graft Function

The outcomes of transplantation have improved, but more than 50% of kidney transplantation (KT) recipients are still reported to have renal function of chronic kidney disease (CKD) stage 3 at 1 year after KT. We reviewed all 1235 patients who received a KT in our institution between 2008 and 2012. Among these recipients, 77 and 289 cases were included in the estimated glomerular filtration rate (eGFR) at 1 year after KT 30-44 (CKD stage 3b) group and eGFR 45-59 (CKD stage 3a) group, respectively. Longer duration of dialysis (odds ratio [OR] = 1.007, 95% confidence interval [CI], 1.000-1.014, P = 0.047), older donors (OR = 1.064, 95% CI, 1.031-1.098, P < 0.001), delayed graft function (OR = 3.601, 95% CI, 1.031-1.098, P < 0.001), BK virus infection (OR = 2.567, 95% CI, 1.242-5.305, P = 0.011), and pneumonia (OR = 4.451, 95% CI, 1.388-14.279, P = 0.012) were contributing factors to eGFR 30-44 mL/min. Especially, ureteral stricture occurred more frequently in eGFR 30-44 group of deceased donor KT. However, acute rejection was not a significant risk factor of lower eGFR. Graft survival was better in the eGFR 45-59 group. However, this difference was smaller in deceased donor KT. Infections and urologic complications are also important contributing factors of lower graft function in CKD stage 3. In addition, dividing CKD stage 3 into subgroups might be more useful in living donor kidney transplantation.

Acute and Chronic Allograft Dysfunction in Kidney Transplant Recipients

Allograft dysfunction after a kidney transplant is often clinically asymptomatic and is usually detected as an increase in serum creatinine level with corresponding decrease in glomerular filtration rate. The diagnostic evaluation may include blood tests, urinalysis, transplant ultrasonography, radionuclide imaging, and allograft biopsy. Whether it occurs early or later after transplant, allograft dysfunction requires prompt evaluation to determine its cause and subsequent management. Acute rejection, medication toxicity from calcineurin inhibitors, and BK virus nephropathy can occur early or later. Other later causes include transplant glomerulopathy, recurrent glomerulonephritis, and renal artery stenosis.