Urolithiasis in allograft kidneys

Comprehensive Approaches to Urolithiasis in Renal Transplants: A Narrative Review

This review addresses the management of urolithiasis in renal transplant recipients, a notably vulnerable group due to the unique anatomical and physiological alterations of the transplanted organ. The prevalence of nephrolithiasis in these patients varies between 0.1% and 6.3%, with a significant impact on graft longevity and function. Surgical access complications due to the renal graft's position on the iliac vessels and the variety of urinary anastomoses complicate the treatment approaches. This study evaluates the effectiveness and outcomes of percutaneous nephrolithotomy (PCNL) and ureteroscopy (URS), two primary minimally invasive strategies for managing graft stones. Through a narrative review using the PubMed and EMBASE databases, it was found that PCNL offers high stone-free rates especially beneficial for large stones, whereas URS provides a less invasive option with a lower risk of complications for small stones. Both techniques require tailored approaches based on stone composition-mostly calcium oxalate-and specific patient anatomical factors. This review underscores the importance of early diagnosis, appropriate treatment selection, and continuous post-treatment monitoring to mitigate risks and promote long-term renal function in transplant recipients.

Percutaneous nephrolithotomy for adult renal transplant de novo graft lithiasis: a single center analysis and systematic review of the literature

INTRODUCTION/OBJECTIVE

Graft stones in renal transplant recipients pose a unique challenge, finding effective interventions to ensure optimal graft function and patient well-being. Various methods of stone clearance have been described for graft stones, including percutaneous nephrolithotomy (PCNL). While PCNL is a promising approach for managing graft stones, specific outcomes and associated characteristics for this approach have not been comprehensively evaluated before. This study aims to evaluate the safety and efficacy of the use of PCNL as the primary intervention of graft stones by assessing stone-free rates (SFR), treatment impact on graft function, and perioperative complications.

METHODS

A retrospective clinical audit was performed for all transplants performed in a single center from 2007 to 2022, which included all graft lithiasis patients who were treated with PCNL. Both perioperative parameters and post-operative outcomes were collected. In addition, a systematic review including articles from MEDLINE, Embase, Web of Science yielded 18 full-text articles published between 1/1/2000 and 15/11/2023. The results pertaining to patients who underwent PCNLs for graft stones were cross-referenced and thoroughly evaluated. The review encompassed a comprehensive analysis of clinical data, postoperative outcomes, and procedural details. The protocol for the systematic review was prospectively registered on PROSPERO (CRD42023486825).

RESULTS

In our center, 6 graft lithiasis patients were treated with PCNL. The initial SFR was 83.3%. SFR at 3 months and 1 year were both 100.0%. SFR at 3 years was 66.7%. Other centers reported initial SFR of 82.6-100.0% (interquartile range). SFR at 3 months, 1 year, 3 years was not well reported across the included studies. Incidence of graft lithiasis ranged from 0.44%-2.41%. Most common presentations at diagnosis were oliguria/anuria/acute kidney injury and asymptomatic. Reported complications included blood loss, transient hematuria, high urine output, sepsis, and damage to surrounding structures. The most commonly reported metabolic abnormalities in transplant lithiasis patients included hyperuricemia and hyperparathyroidism.

CONCLUSION

PCNL is a practical and efficient choice for addressing graft lithiasis, demonstrating excellent stone clearance and minimal perioperative complications. These findings show the importance of PCNL as a primary intervention in this complex patient population.

Current Perspectives on Endourological Ex Vivo Stone Interventions in Kidney Transplantation: A Systematic Review

OBJECTIVE

To conduct a systematic review (SR) of literature to assess the existing evidence concerning the success and complications of endourological ex vivo stone surgeries.

METHODS

Eligible studies for inclusion focused on investigating the success and/or complications related to endourological ex vivo surgeries in donors with nephrolithiasis. A SR was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search included databases of Web of Science, PubMed, and Scopus and only article in English were included. Studies published between 2002 and 2023 included in this SR.

RESULTS

After screening 1726 abstracts, this SR included 16 studies with a total of 209 patients. The mean stone size was 5.6 mm and majority of kidneys contained single stones, located in the lower calyx. After ex vivo endourological stone surgeries, the average stone-free rate was found to be 95.4%. The mean duration of ex vivo surgery was 17.3 minutes. Regarding intraoperative complications, two patients (1%) experienced mucosal injuries during pneumatic lithotripsy. As for postoperative complications, two patients (1%) experienced vascular complications. In terms of urological complications, hematuria was observed in 24 patients (11.5%), while one patient (0.5%) experienced clot formation in renal pelvis. Seven patients (3.3%) had urinary tract infections, and three patients (1.4%) developed urolithiasis during the follow-up. Additionally, one patient (0.5%) experienced complete occlusion of ureteroneocystostomy and required revision.

CONCLUSION

Given the advancements in current technology and techniques, endourological ex vivo stone surgeries are increasingly recognized as an effective and safe option for donors with nephrolithiasis.

TRIAL REGISTRATION

This systematic review was registered under the protocol registration number CRD42024538384/PROSPERO.

Percutaneous Nephrolithotomy for De Novo Urolithiasis After Kidney Transplantation: A Systematic Review of the Literature

Introduction and Objective: Renal transplantation is the treatment for end-stage renal disease that offers better quality of life and survival. Among the possible complications that might affect allografts, urolithiasis might have severe consequences, causing acute kidney injury (AKI) or septic events in immunocompromised patients. Allograft stones might be treated with percutaneous nephrolithotomy (PCNL). The aim of this Cochrane style review was to assess the safety and efficacy of PCNL in patients with renal transplant. Methods: A comprehensive search in the literature was performed including articles between July 1982 and June 2023, with only English original articles selected for this review. Results: The final review encompassed nine articles (108 patients). The mean age was 46.4 ± 8.7 years, with a male:female ratio of 54:44. The average time from transplantation to urolithiasis onset was 47.54 ± 23.9 months. Predominant symptoms upon presentation were AKI (32.3%), followed by urinary tract infection and fever (24.2%), and oliguria (12.9%). The mean stone size was 20.1 ± 7.3 mm, with stones located in the calices or pelvis (41%), ureteropelvic junction (23.1%), or proximal ureter (28.2%). PCNL (22F-30F) was more frequently performed than mini-PCNLs (16F-20F) (52.4% vs 47.6%). Puncture was guided by ultrasound (42.9%), fluoroscopy (14.3%), or both (42.9%). The stone-free rate (SFR) and complication rates were 92.95% (range: 77%-100%) and 5.5%, respectively, with only one major complication reported. Postoperatively, a ureteral stent and nephrostomy were commonly placed in 47%, with four patients needing a second look PCNL. During an average follow-up of 32.5 months, the recurrence rate was 3.7% (4/108), and the mean creatinine level was 1.37 ± 0.28 mg/dL. Conclusions: PCNL remains a safe and effective option in de novo allograft urolithiasis, allowing to treat large stones in one-step surgery. A good SFR is achieved with a low risk of minor complications. These patients should be treated in an endourology center in conjunction with the renal or transplant team.

URS for de-novo urolithiasis after kidney transplantation: a systematic review of the literature

INTRODUCTION

There is a gap in the available literature and guidelines concerning the optimal approach for treating allograft stones, which currently include external shockwave lithotripsy, ureteroscopy and laser lithotripsy, or percutaneous nephrolithotomy. The objective of this systematic review was to evaluate the safety and effectiveness of URS as a treatment option for patients in this scenario.

EVIDENCE ACQUISITION

A comprehensive search of the literature was conducted until August 2023. Only original articles written in English were considered for inclusion. This review has been registered in PROSPERO (registration number CRD42023451154).

EVIDENCE SYNTHESIS

Eleven articles were included (122 patients). The mean age was 46.9±9.5 years, with a male-to-female ratio of 62:49. The preferred ureteral reimplantation technique was the Lich-Gregoire. The mean onset time was 48.24 months. Acute kidney injury, urinary tract infections and fever were the most frequent clinical presentations (18.3% each), followed by hematuria (10%). The mean stone size measured 9.84 mm (±2.42 mm). Flexible URS was preferred over semirigid URS. The stone-free rate stood at 83.35%, while the overall complication rate was 13.93%, with six (4.9%) major complications reported. Stones were mainly composed of calcium oxalate (42.6%) or uric acid (14.8%). Over an average follow-up period of 30.2 months, the recurrence rate was 2.46%. No significant changes in renal function or allograft loss were reported.

CONCLUSIONS

URS remains an efficient choice for addressing de-novo allograft urolithiasis, offering the advantage of treating urinary stones with a good SFR and a low incidence of complications. Procedures should be performed in an Endourology referral center.

Management of de novo nephrolithiasis after kidney transplantation: a comprehensive review from the European Renal Association CKD-MBD working group

The lifetime incidence of kidney stones is 6%-12% in the general population. Nephrolithiasis is a known cause of acute and chronic kidney injury, mediated via obstructive uropathy or crystal-induced nephropathy, and several modifiable and non-modifiable genetic and lifestyle causes have been described. Evidence for epidemiology and management of nephrolithiasis after kidney transplantation is limited by a low number of publications, small study sizes and short observational periods. Denervation of the kidney and ureter graft greatly reduces symptomatology of kidney stones in transplant recipients, which may contribute to a considerable underdiagnosis. Thus, reported prevalence rates of 1%-2% after kidney transplantation and the lack of adverse effects on allograft function and survival should be interpreted with caution. In this narrative review we summarize current state-of-the-art knowledge regarding epidemiology, clinical presentation, diagnosis, prevention and therapy of nephrolithiasis after kidney transplantation, including management of asymptomatic stone disease in kidney donors. Our aim is to strengthen clinical nephrologists who treat kidney transplant recipients in informed decision-making regarding management of kidney stones. Available evidence, supporting both surgical and medical treatment and prevention of kidney stones, is presented and critically discussed. The specific anatomy of the transplanted kidney and urinary tract requires deviation from established interventional approaches for nephrolithiasis in native kidneys. Also, pharmacological and lifestyle changes may need adaptation to the specific situation of kidney transplant recipients. Finally, we point out current knowledge gaps and the need for additional evidence from future studies.

Urolithiasis in Kidney Transplant Patients: A Multicenter KSER Research Series

Background and Objectives: Urolithiasis occurrence is uncommon in kidney transplantation patients, though it has serious implications, including acute kidney injury in the transplanted kidney. This study investigates the leading causes of urolithiasis in kidney transplantation patients, the diagnostic process, and the outcomes of multimodal management. Materials and Methods: Data collection spanned from January 1997 to December 2021, involving kidney transplantation patients with urolithiasis from the database of the Korean Society of Endourology and Robotics (KSER) research committee. Analysis encompassed factors triggering urolithiasis, the diagnostic process, stone attributes, treatment methods, and outcomes. Results: Our analysis included 58 kidney transplantation patients with urolithiasis from eight medical centers. Of these patients, 37 were male and 4 had previous urolithiasis diagnoses. The mean age was 59.09 ± 10.70 years, with a mean duration from kidney transplantation to diagnosis of 76.26 ± 183.14 months. The most frequent method of stone detection was through asymptomatic routine check-ups (54.7%). Among the 58 patients, 51 underwent stone treatment. Notably, 95.3% of patients with ureter stones received treatment, a significantly higher rate than the 66.7% of patients with renal stones (p = 0.010). Success rates showed no significant differences between renal (70%) and ureter stone (78.0%) groups (p = 0.881). Conclusions: Urolithiasis in transplanted kidneys constitutes an acute condition requiring emergency intervention. Endo-urological interventions are effective for kidney transplantation patients with urolithiasis. To ensure prevention and early detection, diligent follow-up and routine imaging tests are necessary.

Kidney stones in renal transplant recipients: A systematic review

INTRODUCTION

Lithiasis in renal graft recipients might be a dangerous condition with a potential risk of organ function impairment.

EVIDENCE ACQUISITION

A systematic literature search was conducted through February 2023. The primary objective was to assess the incidence of lithiasis in kidney transplant (KT) recipients. The secondary objective was to assess the timing of stone formation, localization and composition of stones, possible treatment options, and the incidence of graft loss.

EVIDENCE SYNTHESIS

A total of 41 non-randomized studies comprising 699 patients met our inclusion criteria. The age at lithiasis diagnosis ranged between 29-53 years. Incidence of urolithiasis ranged from 0.1-6.3%, usually diagnosed after 12 months from KT. Most of the stones were diagnosed in the calyces or in the pelvis. Calcium oxalate composition was the most frequent. Different treatment strategies were considered, namely active surveillance, ureteroscopy, percutaneous/combined approach, or open surgery. 15.73% of patients were submitted to extracorporeal shock wave lithotripsy (ESWL), while 26.75% underwent endoscopic lithotripsy or stone extraction. 18.03% of patients underwent percutaneous nephrolithotomy whilst 3.14% to a combined approach. Surgical lithotomy was performed in 5.01% of the cases. Global stone-free rate was around 80%.

CONCLUSIONS

Lithiasis in kidney transplant is a rare condition usually diagnosed after one year after surgery and mostly located in the calyces and renal pelvis, more frequently of calcium oxalate composition. Each of the active treatments is associated with good results in terms of stone-free rate, thus the surgical technique should be chosen according to the patient's characteristics and surgeon preferences.

2022 Recommendations of the AFU Lithiasis Committee: Extracorporeal shock wave lithotripsy (ESWL)

Extracorporeal shock wave lithotripsy (ESWL) is a minimally invasive technique for the fragmentation of urinary tract stones using shock waves under fluoroscopic and/or ultrasound guidance. ESWL results depend on the indication (stone size/composition, clinical context) and also on how it is performed. The stone structure, nature and density (Hounsfield units; evaluated by CT without contrast agent) influence the fragmentation achieved by ESWL. The upper size limit of kidney stones has been lowered to 15mm (1.68cm3) due to the increased risk of steinstrasse with larger sizes and the potential need of anesthesia and ureteral stenting. Conversely, the development of endourological technologies allows a finer stone fragmentation and/or better elimination, thus reducing the risk of steinstrasse and decreasing the potential number of sessions or additional interventions. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendations method (CPR) and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU 2022]) and their adaptability to the French context.

Shockwave Lithotripsy for De-Novo Urolithiasis after Kidney Transplantation: A Systematic Review of the Literature

BACKGROUND

Allograft urolithiasis is an uncommon, challenging, and potentially dangerous clinical problem. Treatment of allograft stones includes external shockwave lithotripsy (SWL), flexible ureteroscopy and lasertripsy (fURSL), or percutaneous nephrolithotomy (PCNL). A gap in the literature and guidelines exists regarding the treatment of patients in this setting. The aim of this systematic review was to collect preoperative and treatment characteristics and evaluate the outcomes of post-transplant SWL for stone disease.

METHODS

A systematic search in the literature was performed, including articles up to March 2023. Only original English articles were selected.

RESULTS

Eight articles (81 patients) were included in the review. Patients were mainly male, with a mean age of 41.9 years (±7.07). The mean stone size was 13.18 mm (±2.28 mm). Stones were predominantly located in the kidney (n = 18, 62%). The overall stone-free rate and complication rates were 81% (range: 50-100%) and 17.2% (14/81), respectively, with only one major complication reported. A pre-operative drainage was placed in eleven (13.5%) patients. Five patients (6.71%) required a second treatment for residual fragments.

CONCLUSIONS

SWL is a safe and effective option to treat de novo stones after transplantation. Larger studies are needed to better address allograft urolithiasis management.

Evaluation of the Effectiveness of Interventions on Nephrolithiasis in Transplanted Kidney

CONTEXT

De Novo nephrolithiasis in renal transplant can have severe consequences since renal transplantation involves a single functioning kidney with medical and anatomical specificities (heterotopic transplantation on iliac vessels, immunosuppressive treatments, and comorbidities).

OBJECTIVE

To systematically review all available evidence on the prevalence of de novo nephrolithiasis in renal transplant, presentation, and stone characteristics, and to report in a meta-analysis the efficacy of stone treatments (extracorporeal shock wave lithotripsy [ESWL], medical treatment, percutaneous nephrolithotomy [PCNL], open surgery, and ureteroscopy).

EVIDENCE ACQUISITION

Medline, Embase, and the Cochrane Library were searched up to November 2021 for all relevant publications reporting the management of de novo nephrolithiasis in renal allografts. The primary outcome was stone-free rate (SFR) at 3 mo. Secondary outcomes included prevalence, stone characteristics (size, density, and composition), symptoms on presentation, need for drainage, complications, and recurrence. Data were narratively synthesized in light of methodological and clinical heterogeneity, and a meta-analysis was performed for SFR. The risk of bias of each included study was assessed.

EVIDENCE SYNTHESIS

We included 37 retrospective studies with 553 patients and 612 procedures; of the 612 procedures 20 were antegrade ureteroscopy, 154 retrograde ureteroscopy, 118 PCNL, 25 open surgery, 155 ESWL, and 140 surveillance/medical treatment. The prevalence of nephrolithiasis in renal transplant was 1.0%. The mean stone size on diagnosis was 11 mm (2-50). The overall SFR at 3 mo was 82%: 96% with open surgery, 95% with antegrade ureteroscopy, 86% with PCNL, 81% with retrograde ureteroscopy, and 75% with ESWL.

CONCLUSIONS

De novo nephrolithiasis in renal transplant is an infrequent condition. A high SFR were obtained with an antegrade approach (ureteroscopy, PCNL, and open approach) that should be considered in renal transplant patients owing to the heterotopic position of the renal graft. The choice of technique was correlated with stone size: generally ureteroscopy and ESWL for stones 11-12 mm (mean stone size) versus PCNL and open surgery for 17-25 mm stones.

PATIENT SUMMARY

De novo nephrolithiasis in renal transplants is an infrequent situation that can have severe consequences on the function of the renal graft. We evaluated the efficacy of each treatment and noted that antegrade approaches (open surgery, percutaneous nephrolithotomy, and antegrade ureteroscopy) were associated with the highest stone-free rate. As opposed to the management of nephrolithiasis in native kidney, an antegrade approach should be considered more in renal transplant patients.

Is There Still a Place for Percutaneous Nephrolithotomy in Current Times?

Background: Percutaneous nephrolithotomy (PCNL) and its miniaturized modifications are usually considered the standard surgical options for large (>20 mm) staghorn and infected stones. Moreover, PCNL is a viable alternative to retrograde intrarenal surgery (RIRS) for smaller stones (<20 mm) in the presence of anatomical malformations or inaccessible lower pole stones. However, due to the advancements in laser and scope technology, RIRS is expanding its indications with the potential benefits of lower complications and a shorter hospital stay. Methods: A literature search using the PUBMED database from inception to June 2022 was performed to explore the current role of PCNL in endourology. The analysis involved a narrative synthesis. Results: PCNL confirmed its role in the treatment of large and complex stones; moreover, miniaturized PCNL has become more competitive, gaining space among classic indications of flexible ureteroscopy. Conclusions: considering all the evaluated subgroups, we can conclude that PCNL is an old fascinating procedure and is here to stay.

Flexible Ureteroscopy as the New Standard for the Management of Renal Transplant Urolithiasis <15 mm: A Single-Center Experience

Objectives: To determine the safety and efficacy of flexible ureteroscopy in the treatment of transplant urolithiasis. Materials and Methods: We reviewed a single-center series of 2652 patients who underwent surgical treatment for nephrolithiasis at our institution from 2009 to the present day to identify all patients undergoing ureteroscopy for treatment of transplant lithiasis. Results: We identified 18 patients who underwent ureteroscopy for treatment of urolithiasis within the transplanted kidney or ureter. The majority of the procedures were performed using a retrograde approach with flexible ureteroscopy, with one patient undergoing antegrade ureteroscopy and two patients requiring semirigid ureteroscopy. Holmium:yttrium-aluminum-garnet laser lithotripsy was utilized in all but one case, which was performed using basket extraction. There were no intraoperative complications reported. Four patients had small stone fragments on postoperative imaging, three of which were observed. One patient required repeat ureteroscopy for persistent distal ureteral stone. Conclusion: Retrograde ureteroscopy is a feasible, safe, and effective intervention for the treatment of transplant lithiasis. Minimal intraoperative or postoperative complications were reported, and only one patient required additional intervention for residual stone burden.

[Urinary stones in renal transplant recipients and donors: The French guidelines from CTAFU]

OBJECTIVE

To define guidelines for the management of kidney stones in kidney transplant (KTx) donor or recipients.

METHOD

Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU to report kidney stone epidemiology, diagnosis and management in KTx donors and recipients with the corresponding level of evidence.

RESULTS

Prevalence of kidney stones in deceased donor is unknown but reaches 9.3% in living donors in industrialized countries. Except in Maastrich 2 donors, diagnosis is done on systematic pre-donation CT scan according to standard french procedure. No prospective study has compared therapeutic strategies available for the management of kidney stones in KTx donor: ureteroscopy or an extra corporeal lithotripsy in case of living donor prior to donation, ex vivo approach (pyelotomy or ureteroscopy), ureterocopy in the KTx recipient or surveillance. De novo kidney stones result from a lithogenesis process to be identified and treated in order to avoid recurrences. The context of solitary functional kidney renders the prevention of recurrence of great importance. Diagnosis is suspected when identification of a renal graft dysfunction, hematuria or urinary tract infection with renal pelvis dilatation. Stone size and location are determined by computed tomography. There are no prospective, controlled studies on kidney stone management in the KTx. The therapeutic strategies are similar to standard management in general population.

CONCLUSION

These French recommendations should contribute to improve kidney stones management in KTx donor and recipients.

[Urolithiasis of the kidney transplanted patient in south Tunisia: A 17-year experience]

INTRODUCTION

Urolithiasis in a kidney transplanted patient is an uncommon but complex urological complication. Its potential severity comes from its occurrence on a solitary kidney and on a field of immunosuppression. The aim of our study is to assess the incidence, characteristics and course of urolithiasis in our series.

METHODS

A retrospective study was performed. We included kidney transplanted patients between November 2002 and November 2019 and presenting lithiasis during their follow-up. Clinical, biological and radiological data were collected as well as lithiasis disease related data. The management of and patient's evolution were also specified.

RESULTS

Seven of 416 kidney transplanted patients developed lithiasis during their follow-up with an incidence of 1.6 %. The mean age at lithiasis diagnosis was 36.5 years [24-55 years], the sex ratio was 1.3. They developed stones after mean follow-up of 67 months [4-168 months]. The stones' size varied from 2 to 18mm. Treatment was alkalisation in 3 cases, extracorporeal lithotripsy in 2 cases, a double J stent in 3 cases and pyelolithotomy in 2 cases. Four patients had multiple treatments. Three patients had 1 residual stone during evolution (7mm average diameter), 1 microlithiasis, 1 lost to follow-up after treatment and only 2 (out of 7) were "stone free". Furthermore, lithiasis didn't damage the graft survival after a median follow-up of 62 months post-treatment.

CONCLUSION

Urolithiasis in the kidney transplanted patient requires an adapted multidisciplinary management. Its skill is a challenge for both the nephrologist and urologist.

Treatment of recurrent renal transplant lithiasis: analysis of our experience and review of the relevant literature

BACKGROUND

Renal transplant lithiasis is a rather unusual disease, and the recurrence of lithiasis presents a challenging situation.

METHODS

We retrospectively analyzed the medical history of one patient who suffered renal transplant lithiasis twice, reviewed the relevant literature, and summarized the characteristics of this disease.

RESULTS

We retrieved 29 relevant studies with an incidence of 0.34 to 3.26% for renal transplant lithiasis. The summarized incidence was 0.52%, and the recurrence rate was 0.082%. The mean interval after transplantation was 33.43 ± 56.70 mo. Most of the patients (28.90%) were asymptomatic. The management included percutaneous nephrolithotripsy (PCNL, 22.10%), ureteroscope (URS, 22.65%), extracorporeal shockwave lithotripsy (ESWL, 18.60%) and conservative treatment (17.13%). In our case, the patient suffered from renal transplant lithiasis at 6 years posttransplantation, and the lithiasis recurred 16 months later. He presented oliguria, infection or acute renal failure (ARF) during the two attacks but without pain. PCNL along with URS and holmium laser lithotripsy were performed. The patient recovered well after surgery, except for a 3 mm residual stone in the calyx after the second surgery. He had normal renal function without any symptoms and was discharged with oral anticalculus drugs and strict follow-up at the clinic. Fortunately, the calculus passed spontaneously about 1 month later.

CONCLUSIONS

Due to the lack of specific symptoms in the early stage, patients with renal transplant lithiasis may have delayed diagnosis and present ARF. Minimally invasive treatment is optimal, and the combined usage of two or more procedures is beneficial for patients. After surgery, taking anticalculus drugs, correcting metabolic disorders and avoiding UIT are key measures to prevent the recurrence of lithiasis.

Post-renal transplant urolithiasis in children: an increasingly diagnosed complication: a retrospective cohort study

OBJECTIVE

Urolithiasis in renal transplant (RTx) recipients is a potential cause of allograft loss if obstruction is untreated. It is not clear if paediatric transplant recipients are following the global trend for increased prevalence of urolithiasis over time.

DESIGN/SETTING/PATIENTS

A retrospective chart review was undertaken to evaluate the frequency, risk factors and characteristics of post-RTx urolithiasis over two decades (1995-2016), in a tertiary Australian paediatric hospital.

RESULTS

Stones were diagnosed in 8 of 142 (5.6%) recipients, 6 of whom were transplanted in the latter decade. All patients were male, with a median age 4.9 years and median weight 11.8 kg. Presentation was with haematuria (n=4), pain (n=2), dysuria (n=2), stone passage (n=1) and asymptomatic (n=1). Time to presentation was bimodal; three stones were identified in the initial 3 months post RTx and the remainder after 31-53 months. Two stones were in association with retained suture material and two patients had recurrent urinary tract infections. The average stone size was 8.4 mm. Five stones were analysed; all contained calcium oxalate, three were mixed, including one with uric acid. Five (83.3%) children had hypercalciuria but none had hypercalcaemia. Cystolithotripsy was the the most common treatment (n=5), in combination with citrate supplementation. No graft was lost due to stones.

CONCLUSIONS

Calculi occur with increasing frequency after renal transplantation. Clinicians need a high index of suspicion as symptoms may be atypical in this population. The cause for the increased frequency of stones in transplant recipients is not clear but is in keeping with the increase seen in the general paediatric population.

Evaluation of Deceased Kidney Donors for Renal Stone Disease: Is Computed Tomography Needed?

Objective

To investigate the clinical consequences of neglected risk of urolithiasis in deceased kidney donors in routine clinical practice, this study focused on different management options for transplanted allograft stones, and tried to find new solutions for more accurate detection of urolithiasis in deceased kidney donors prior to renal transplantation.

Methods and Results

The overall prevalence of stone disease in endemic countries is between 7 and 29%. Because of the increased risk for stone disease in epidemic countries, screening renal grafts from deceased donors necessitates more sensitive imaging tests. Despite well established procedures on preoperative living related renal donor evaluation, there is no consensus on a preoperative imaging tool in cadaveric renal donor evaluation. The most commonly used imaging modality in deceased renal donors is ultrasonography. The overall sensitivity and specificity of ultrasonography for kidney stones are 45 and 88%, respectively. Use of a computed tomography scan for renal diseases, especially for urinary stones is now almost a routine test in clinical practice. Its sensitivity for renal stones < 3 mm is 85%, whereas for renal stones > 3 mm it is 100%.

Conclusion

The use of radiological modalities i.e. computed tomography with higher sensitivity in deceased donors prior to renal transplantation seems reasonable in urinary stone epidemic countries.

Ex-vivo ureteroscopy of deceased donor kidneys

INTRODUCTION

When encountered, the ideal management of lithiasis in deceased donor kidneys is not well-defined. With advances in endourological techniques, minimally invasive treatments are becoming an increasingly viable option. We set out to describe our experience performing ex-vivo ureteroscopy on cadaveric donor kidneys, including one in which the procedure was completed on-pump.

METHODS

A retrospective chart review was undertaken to identify patients who had undergone ex-vivo ureteroscopy prior to cadaveric renal transplant. Four patients were identified, including one in which the procedure was done with the kidney remaining on-pump. The surgical technique and subsequent data were reviewed.

RESULTS

Ex-vivo ureteroscopy was successfully completed in all four instances without intraoperative complication. All kidneys were endoscopically stone-free. Creatinine nadirs ranged from 0.8-1.4. All four patients remained stone-free at a mean followup of 13 months.

CONCLUSIONS

Our series provides further evidence as to the safety and efficacy of ex-vivo ureteroscopy prior to transplantation in cadaveric renal transplants and describes a novel technique in the form of on-pump ex-vivo ureteroscopy.

Incidence of kidney stones in kidney transplant recipients: A systematic review and meta-analysis

AIM

To evaluate the incidence and characteristics of kidney stones in kidney transplant recipients.

METHODS

A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the inception of the databases through March 2016. Studies assessing the incidence of kidney stones in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of kidney stones.

RESULTS

Twenty one studies with 64416 kidney transplant patients were included in the analyses to assess the incidence of kidney stones after kidney transplantation. The estimated incidence of kidney stones was 1.0% (95%CI: 0.6%-1.4%). The mean duration to diagnosis of kidney stones after kidney transplantation was 28 ± 22 mo. The mean age of patients with kidney stones was 42 ± 7 years. Within reported studies, approximately 50% of kidney transplant recipients with kidney stones were males. 67% of kidney stones were calcium-based stones (30% mixed CaOx/CaP, 27%CaOx and 10%CaP), followed by struvite stones (20%) and uric acid stones (13%).

CONCLUSION

The estimated incidence of kidney stones in patients after kidney transplantation is 1.0%. Although calcium based stones are the most common kidney stones after transplantation, struvite stones (also known as “infection stones”) are not uncommon in kidney transplant recipients. These findings may impact the prevention and clinical management of kidney stones after kidney transplantation.

[Urinary lithiasis in renal transplant recipient]

OBJECTIVES

To report epidemiology and characteristics of urinary lithiasis and its management in kidney allograft at the time of organ procurement or after kidney transplantation.

MATERIAL AND METHODS

An exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords (MESH): urinary lithiasis, stone, kidney transplantation. Publications obtained were selected based on methodology, language, date of publication (last 10 years) and relevance. Prospective and retrospective studies, in English or French, review articles; meta-analysis and guidelines were selected and analyzed. This search found 58 articles. After reading, 37 were included in the text based on their relevance.

RESULTS

Frequency of urinary lithiasis in renal transplant recipient is similar to those observed in the general population. Generally, urinary lithiasis of the graft is asymptomatic because of renal denervation after organ procurement and transplantation. Nevertheless, this situation may be at high risk due to the immunosuppressed state of the recipient with a unique functioning kidney. Most of the time, the diagnosis is incidental during routine post-transplantation follow-up. Management of urolithiasis in renal transplant recipient is similar to that performed in general population.

CONCLUSION

Due to its potential severity in transplanted immunosuppressed patients with a sole kidney, urolithiasis requires expert urological management.

The development and current status of minimally invasive surgery to manage urological complications after renal transplantation

Introduction:

In the past, urological complications after renal transplantation were associated with significant morbidity. With the development and application of endourological procedures, it is now possible to manage these cases with minimally invasive techniques.

Materials and Methods:

A MEDLINE search for articles published in English using key words for the management of urological complications after renal transplantation was undertaken. Forty articles were selected and reviewed.

Results:

The incidence of urological complications postrenal transplantation was reported to be 2–13%. Ureteric leaks occurred in up to 8.6%, and 55% were managed endourologically. The incidence of lymphocele was as high as 20%, and less that 12% of the cases required treatment. Ureteric stricture was the most common complication, and endourological management was successful in 50–70%. The occurrence of complicated vesicoureteral reflux was 4.5%, and 90% of low-grade reflux cases were successfully treated with deflux injections. Stones and obstructive voiding dysfunction occurred in about 1% of kidney transplant recipients.

Conclusion:

Minimally invasive techniques have a critical role in the management of urological complications after renal transplantation. Urinary leakage should be managed with complete decompression. Percutaneous drainage should be the first line of treatment for lymphocele that is symptomatic or causing ureteric obstruction. Laparoscopic lymphocele deroofing is successful in aspiration-resistant cases. Deflux is highly successful for the management of complicated low-grade kidney transplant reflux. The principles of stone management in a native solitary kidney are applied to the transplanted kidney. Early identification and treatment of bladder outlet obstruction after renal transplantation can prevent urinary leakage and obstructive uropathy.

Treatment of Kidney Stone in a Kidney-Transplanted Patient with Mini-Percutaneous Laser Lithotripsy: A Case Report

We report a case of a kidney-transplanted patient with urolithiasis treated with mini-percutaneous laser lithotripsy. The patient presented with renal dysfunction and graft hydronephrosis. Diagnostic procedures revealed ureterolithiasis as a cause of obstruction, and percutaneous nephrostomy was inserted as a temporary solution. Before surgery, the stone migrated to the renal pelvis. Mini-percutaneous laser lithotripsy was successfully performed, and during surgery, all stone fragments were removed. Six months after successful treatment, the patient has good functioning and stone-free graft.

Lithiasis of the renal allograft, a rare urological complication following renal transplantation: a single-center experience of 2,045 renal transplantations

BACKGROUND AND PURPOSE

Urinary lithiasis represents an unusual urologic complication in renal transplantation, with an incidence of 0.17%-1.8%.We present our experience with renal graft lithiasis in our series of renal transplantations.

MATERIAL AND METHODS

We reviewed the medical records for 2045 patients who underwent kidney transplantation from January 1983 to July 2013. Among the grafts, 9 patients were found to have allograft lithiasis. In 6 cases, the calculi were localized within the renal unit, and in 3 cases in the ureter. Two of the patients had relapsed after a few years from the first treatment. In both of them the stones were localized again in the ureter.

RESULTS

In our series, incidence of graft lithiasis was 0.44% (n = 9). Three of the 9 patients (33.3%) were treated via percutaneous nephrolithotripsy (PCNL), 3 (33.3%) underwent extracorporeal shockwave lithotripsy (ESWL), 2 (22.2%) passed their stones spontaneously, and 1 (11.1%) underwent PCNL after 2 failed ESWL interventions. All patients are currently stone free but still remain under close urologic surveillance.

CONCLUSIONS

Urinary stone formation can lead to significant morbidity and graft loss. The treatment options should be similar to those for patients in the general population. Long-term follow-up is substantial to determine the outcome and to prevent the recurrence.

Ex vivo pyelotomy, nephroscopy and holmium laser lithotripsy of a staghorn stone in a donor kidney prior to renal transplant

This case report presents the diagnostic and treatment procedures of stone removal from the kidney of a 67-year-old donor, the transplantation of the kidney to a 65-year-old recipient, and the postoperative course until the end of hospitalization. Computed tomography performed before collecting the organ showed a staghorn stone in the renal pelvis and lower calyces in the right donor kidney. The stones were removed ex-vivo using a rigid ureteroscope and a holmium laser prior to transplantation. Then the organ was transplanted to the left iliac fossa of a 65-year-old man with end-stage renal failure. The authors think there is a possibility of increasing the kidney pool, by using organs containing large calculi. In such cases stones should be removed before the operation and the patient should be monitored regularly, especially in the first months after the transplant.

Outpatient percutaneous nephrolithotomy in a renal transplant patient: World's first case

Percutaneous nephrolithotomy (PCNL) is an established safe and effective surgical treatment option for renal calculi in renal allografts. The advent of tubeless PCNL has led to reports of ambulatory or outpatient PCNL. This case report describes the successful outpatient management of a 49-year-old female with a symptomatic renal pelvic calculus in her transplanted kidney. Tubeless PCNL successfully removed the stone, free of complication, and the patient was discharged 2 hours and 17 minutes after the procedure in stable condition with minimal pain. This is, to the best of our knowledge, the first successful case of outpatient tubeless PCNL in a transplanted kidney.

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.

The current role of endourologic management of renal transplantation complications

Introduction. Complications following renal transplantation include ureteral obstruction, urinary leak and fistula, urinary retention, urolithiasis, and vesicoureteral reflux. These complications have traditionally been managed with open surgical correction, but minimally invasive techniques are being utilized frequently. Materials and Methods. A literature review was performed on the use of endourologic techniques for the management of urologic transplant complications. Results. Ureterovesical anastomotic stricture is the most common long-term urologic complication following renal transplantation. Direct vision endoureterotomy is successful in up to 79% of cases. Urinary leak is the most frequent renal transplant complication early in the postoperative period. Up to 62% of patients have been successfully treated with maximal decompression (nephrostomy tube, ureteral stent, and Foley catheter). Excellent outcomes have been reported following transurethral resection of the prostate shortly after transplantation for patients with urinary retention. Vesicoureteral reflux after renal transplant is common. Deflux injection has been shown to resolve reflux in up to 90% of patients with low-grade disease in the absence of high pressure voiding. Donor-gifted and de novo transplant calculi may be managed with shock wave, ureteroscopic, or percutaneous lithotripsy. Conclusions. Recent advances in equipment and technique have allowed many transplant patients with complications to be effectively managed endoscopically.

Lithiasis in 1,313 kidney transplants: incidence, diagnosis, and management

BACKGROUND

Renal transplantation remains the optimal treatment of patients with end-stage renal disease. Urinary lithiasis represents an unusual urologic complication in renal transplantation, with an incidence of <1%. Today, recipients of kidneys from deceased donors are more likely to receive grafts with undiagnosed lithiasis, which does not occur in patients from living donors, owing to screening with computerized tomography.

OBJECTIVE

The aim of this study was to evaluate the incidence, diagnosis, and therapeutic management of renal lithiasis in transplanted kidneys at a single institution.

METHODS

We reviewed the medical records for 1,313 patients who underwent kidney transplantation from February 1968 to February 2011.

RESULTS

Among the grafts, 17 patients (1.29%) had nephrolithiasis: 9 women and 8 men. Ages ranged from 32 to 63 years (mean = 45.6 years). Fifteen patients received kidneys from cadaveric and only 2 from living related donors. Two stones, both located inside the ureter, were identified during transplant surgery (11.7%). Three instances of lithiasis were incidentally diagnosed by ultrasound during graft evaluation, within 7 days after surgery (17.6%); all 3 were in the calyces. The 12 remaining patients had the stones diagnosed later (70.58%): 6 in the calyces, 3 in the renal pelvis, and 3 inside the ureter.

CONCLUSIONS

Urinary lithiasis is a rare complication in renal transplantation. In most patients the condition occurs without pain. The diagnosis and treatment options for graft urolithiasis are similar to those patients with nephrolithiasis in the general population. Extracorporeal shock wave lithotripsy (ESWL) was the most common treatment method.

Management of stones in abnormal situations

Stones in abnormal situations present a management conundrum to the urologist. Many of these situations are relatively rare and literature is scanty on the appropriate management. We review the current literature on the management of stones in the setting of pregnancy, calyceal diverticulum, urinary diversions, pelvic kidneys, transplant kidneys, autosomal dominant polycystic kidney disease, horseshoe kidneys, and other renal anomalies. The aims of treatment are complete stone-free status. The modality of treatment should be individualized to the size and location of stone and type of abnormal situation confronted.

Decrease in and management of urolithiasis after kidney transplantation

PURPOSE

Urolithiasis after kidney transplantation can involve several contributing factors and the treatment strategy is open to question. We determined the incidence and management of urolithiasis in kidney recipients.

MATERIALS AND METHODS

We retrospectively reviewed a single center series of 3,000 kidney graft recipients during 32 years to identify those with urolithiasis. We analyzed data by the prevalence per decade, including perioperative procedures (preoperative assessment, anastomosis type and urinary drainage) and long-term followup (urinary stenosis, time to presentation, size, site, treatment type, renal function and survival).

RESULTS

We identified 31 cases and noted a significant decrease in incidence from 2.1% to 0.6% during the 3 decades. Excluding 4 cases of donor in situ stones the mean time to diagnosis was 8.5 years. Surgical risk factors were ureteral obstruction in 41% of cases, infravesical obstruction in 14% and urinary-digestive anastomosis in 14%. A total of 12 cases (38%) were observed exclusively with 2 of spontaneous passage. With minor adaptations all mini-invasive procedures, including extracorporeal shock wave lithotripsy, endoscopy and percutaneous nephrolithotomy, were feasible in graft recipients. Antegrade procedures were facilitated by the ventral position of the graft. Eight patients (25%) were treated with open surgical ureteroureteral anastomosis.

CONCLUSIONS

Prevention with a perioperative Double-J® stent and early treatment of ureteral obstruction have decreased and stabilized the urolithiasis rate at around 0.6%. Careful surveillance or any currently available instrumental treatments of urinary stones can be valid options.

Ureteroscopy for transplant lithiasis

BACKGROUND AND PURPOSE

The optimal management of renal and ureteral calculi in transplanted kidneys is not well defined. Although larger (>1.5 cm) stone burdens are generally treated with percutaneous nephrolithotomy (PCNL), smaller stones may be reasonably approached with retrograde or antegrade ureteroscopy (URS). We report our multicenter experience with URS for transplant lithiasis.

PATIENTS AND METHODS

URS performed for stone disease within a transplanted kidney were retrospectively identified at three stone-referral centers between 2006 and 2011. Demographic and disease parameters were recorded, as were perioperative and postoperative details.

RESULTS

Twelve patients underwent URS for a calculus in a transplant renal unit and/or ureter. For retrograde procedures (7), access to the ureteral orifice was facilitated by the use of a Kumpe catheter; a two-wire (safety and working guidewire) technique was used. For antegrade procedures (5), the ureteroscope was passed into the kidney using a two-wire technique without tract dilation. All stones but one necessitated holmium:yttrium-aluminum-garnet laser lithotripsy with extraction of stone fragments. All patients were stone free on postoperative imaging except for one patient with a 2-mm fragment that was observed. Stone analysis included calcium oxalate (6), calcium phosphate (4), and struvite (1).

CONCLUSION

Antegrade and retrograde URS are safe and effective treatments for patients with simple stone burdens in a transplanted kidney. Although retrograde access to the ureter can be challenging, specialized techniques and modern endoscope technology facilitate this process. Antegrade URS for small stone burdens can be performed safely and effectively without tract dilation.

Incidental kidney stones: a single center experience with kidney donor selection

The presence of kidney stones has been a relative contraindication for living donation. With the widespread use of more sensitive imaging techniques as part of the routine living donor workup, kidney stones are more frequently detected, and their clinical significance in this setting is largely unknown. Records from 325 potential kidney donors who underwent MRA or CT-angiography were reviewed; 294 proceeded to donation. The prevalence of kidney stones found incidentally during donor evaluation was 7.4% (24 of 325). Sixteen donors with stones proceeded with kidney donation. All incidental calculi were nonobstructing and small (median 2 mm; range 1-9 mm). Eleven recipients were transplanted with allografts containing stones. One recipient developed symptomatic nephrolithasis after transplantation. This recipient was found to have newly formed stones secondary to hyperoxaluria, suggesting a recipient-driven propensity for stone formation. The remaining ten recipients have stable graft function, postoperative ultrasound negative for nephrolithiasis, and no sequelae from stones. No donor developed symptomatic nephrolithiasis following donation. Judicious use of allografts with small stones in donors with normal metabolic studies may be acceptable, and careful follow-up in recipients of such allografts is warranted.

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.

Ureteroscopic management of urological complications after renal transplantation

OBJECTIVE

To determine the feasibility, safety and efficacy of diagnostic and therapeutic ureteroscopy in renal allograft ureters.

MATERIAL AND METHODS

We reviewed 1560 consecutive renal allografts performed between June 1989 and February 2002. A total of 28 patients (1.8%) had indications for an endoscopic procedure on the allograft ureter, as follows: obstructive ureteral calculi with a history of failed extracorporeal shock-wave lithotripsy, n=6; suspected ureteral stricture, n=3; upwardly migrated ureteral stents, n=9; and ureteral stricture at the ureteroneocystostomy site, n=10. Ureters were anastomosed to the bladder using the Leadbetter-Politano and Lich-Gregoire methods in six and 22 cases, respectively. Ureteroscopies were performed with a semi-rigid 9.8 F Wolf ureteroscope.

RESULTS

Identification of the ureteral orifice and insertion of a guide-wire into it was successful in 19 cases (68%). If we exclude the 10 patients with ureteral stricture, ureteroscopy was successful in 13/18 cases (72%). Four ureteral calculi (67%) were removed with the ureteroscope. Seven out of nine migrated stents (78%) were retrieved. Four patients with ureteral stricture at the ureteroneocystostomy site (40%) underwent successful ureteral dilatation and double-J ureteral catheters were also inserted. Diagnostic ureteroscopy was successful in all cases. Two complications (one urinary leakage and one symptomatic urinary tract infection) occurred and were managed conservatively.

CONCLUSIONS

Ureteral endoscopy is a safe and effective method for the management of urological complications after renal transplantation. This procedure can be considered the first choice, in preference to percutaneous and antegrade modalities.

Percutaneous nephrolithotomy success in the transplant kidney

PURPOSE

Treatment for symptomatic calculi in the transplanted kidney can be problematic. Percutaneous nephrolithotomy has routinely been used but concerns exist about potential injury to adjacent organs using a percutaneous access technique. We report our experience with percutaneous nephrolithotomy in the transplant kidney.

MATERIALS AND METHODS

A retrospective chart review from 1988 to the present was performed of all cases of a renal transplant and subsequent renal calculi treated with percutaneous nephrolithotomy.

RESULTS

We identified 13 patients with a renal transplant who underwent percutaneous nephrolithotomy. Presenting symptoms included renal failure in 46.1% of cases, hematuria in 23.1%, urinary tract infection/pyelonephritis in 23.1%, pain in 15.4%, fever in 7.7% and hydronephrosis in 7.7%. Average calculus size was 1.36 cm (range 0.2 to partial staghorn). A single access tract was used in 12 cases and 2 access tracts were used in 1. Ultrasonic lithotripsy was performed in 10 cases, basket extraction was performed in 3 and the 2 techniques were performed in 1. No intraoperative complications occurred. Nephrostogram 24 hours after the procedure demonstrated no residual fragments in 10 patients (76.9%). Repeat endoscopy was required in 3 patients to achieve subsequent stone-free status. Postoperative complications developed in 3 patients, including sepsis, gastrointestinal bleeding and herpes esophagitis, respectively. Mean followup was 5.3 years (range 0.6 to 9). The single stone recurrence was treated with shock wave lithotripsy. Mean creatinine was stable at 2.0 mg/dl (range 0.9 to 3.9) preoperatively to 1.7 mg/dl (range 0.9 to 2.6) at the last visit (p = 0.311).

CONCLUSIONS

Percutaneous nephrolithotomy is safe and effective in the transplanted kidney. Minimal postoperative complications were noted and stone-free status was achieved in all cases. At long-term followup there were few stone recurrences with stable graft function after the procedure.