Graft Ureter Research Articles

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.

V06-07 ROBOTIC RADICAL CYSTECTOMY IN RENAL TRANSPLANT PATIENTS: THE INDOCYANINE GREEN (ICG) TECHNIQUE

You have accessJournal of UrologyCME1 Apr 2023V06-07 ROBOTIC RADICAL CYSTECTOMY IN RENAL TRANSPLANT PATIENTS: THE INDOCYANINE GREEN (ICG) TECHNIQUE Chi Hang Yee, Timothy Chang Kidd Ng, Steffi Kar Kei Yuen, Mandy Ho Man Tam, Jeremy Yuen Chun Teoh, Peter Ka Fung Chiu, Chi Kwok Chan, and Chi Fai Ng Chi Hang YeeChi Hang Yee More articles by this author , Timothy Chang Kidd NgTimothy Chang Kidd Ng More articles by this author , Steffi Kar Kei YuenSteffi Kar Kei Yuen More articles by this author , Mandy Ho Man TamMandy Ho Man Tam More articles by this author , Jeremy Yuen Chun TeohJeremy Yuen Chun Teoh More articles by this author , Peter Ka Fung ChiuPeter Ka Fung Chiu More articles by this author , Chi Kwok ChanChi Kwok Chan More articles by this author , and Chi Fai NgChi Fai Ng More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003274.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The risk of developing bladder cancer in transplant populations is higher compared with the general population. The presence of a graft kidney can be an additional challenge to surgeons when radical cystectomy is contemplated for this group of patients. The study is to review the outcome of robotic radical cystectomy in patients with a graft kidney in-situ by the use of the indocyanine green (ICG) technique. METHODS: Consecutive cases of robotic radical cystectomy in patients with history of renal transplant were reviewed. Pre-operative graft ureter catherterization was performed and robotic radical cystectomy was executed with the aide of ICG to identify the graft ureter in order to preserve its maximal length. Peri-operative and oncological outcome were assessed. RESULTS: Between 2019 to 2022, 3 renal transplant recipients underwent robotic radical cystectomy and intra-corporeal ileal conduit reconstruction, with the indication of pathologically confirmed muscle-invasive disease. One of the patients had robotic bilateral nephroureterectomy performed in the same setting. Mean patient age was 68.0±8.5 years, mean interval between renal transplant and the index cystectomy surgery was 20.0±2.6 years. All patients’ graft were located at the right lower quadrant. Operation time for the patient with additional bilateral nephroureterectomy was 543 minutes. For the other 2 patients, the operation time were 300 minutes and 227 minutes. Mean hospital stay was 7.7±1.2 days. No post-operative complication was observed 3 months after the operation. In all cases, the graft ureter could be identified with the ICG technique. CONCLUSIONS: Robotic radical cystectomy in the setting of renal transplant recipient is a safe alternative to its open surgery counterpart. The ICG technique provides an effective option to identify the graft ureter during dissection in order to gain the maximal length for subsequent reconstruction. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e510 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Chi Hang Yee More articles by this author Timothy Chang Kidd Ng More articles by this author Steffi Kar Kei Yuen More articles by this author Mandy Ho Man Tam More articles by this author Jeremy Yuen Chun Teoh More articles by this author Peter Ka Fung Chiu More articles by this author Chi Kwok Chan More articles by this author Chi Fai Ng More articles by this author Expand All Advertisement PDF downloadLoading ...

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

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

Ultrashort anisoperistaltic end-to-side ureteroureterostomy in renal transplantation.

The improvement of surgical techniques in kidney transplantation aims to reduce the incidence of post-transplant complications, contributing to the reduction of hospital stay, related costs, morbidity and mortality, in addition to improving the quality of life of patients. The choice of the best technique is influenced by several factors and the most common technique for urinary tract reconstruction in transplants is performed with implantation of the ureter of the graft in the caudal position, with the anastomosis performed in the bladder. However, the kidney pole can be inverted and the graft ureter anastomosis can be performed directly on the recipient's ureter, facilitating venous and ureteral anastomoses and reducing urological complications.

Reconstructive plastic surgery on the urinary tract of a kidney transplant

We present a clinical case of urolithiasis. A patient diagnosed with stage 5 chronic kidney disease due to autosomal dominant polycystic kidney disease after bilateral nephrectomy underwent kidney transplantation with ureteral graft stenting. Two months after the operation, a stone was found in the upper third of the ureteral graft, complicated by necrosis in this area. Reconstructive plastic surgery on the ureter of the transplanted kidney with removal of the ureteral stone achieved the desired clinical effect.

Urothelial carcinoma of the graft kidney with molecular analyses: a rare case report

BackgroundMalignancy after transplantation is a leading cause of death among kidney transplant recipients. However, donor-derived malignancies are rare. We report a case of a high grade papillary urothelial carcinoma arising in a transplanted kidney.Case presentationA 62-year-old female who received a kidney transplantation more than 30 years ago presented with urinary tract infection, acute renal failure, and hydronephrosis of the transplant kidney. Anterograde nephrostogram showed a large filling defect in the lower pole of the transplant kidney and in the proximal 3–4 cm of the ureter. A biopsy from the renal pelvic mass showed a high grade urothelial carcinoma. She underwent an anterior exenteration, resection of both transplant and native kidneys and bilateral pelvic lymph node dissection. Pathologic examination showed a high grade papillary urothelial carcinoma which appeared to arise in the pelvis of the graft kidney, involve the graft ureter and native urinary bladder. The tumor had metastasized to one left obturator lymph node but spared the two native kidneys and ureters. Short tandem repeat (STR) analysis confirmed the tumor to be of donor origin. Next-generation sequencing identified amplification of TERT and loss of CDKN2A/CDKN2B in the primary tumor.ConclusionWhile it is known that transplant recipients have an increased risk of urothelial carcinoma compared to the general population, the lack of the well-documented risk factors, such as older age at transplantation, BK polyomavirus infection, and prolonged post-transplantation history and dissemination of the tumor in this case shed light on the de novo tumorigenesis of the graft kidney within the host microenvironment. Amplification of Telomerase reverse transcriptase (TERT) and loss of cyclin dependent kinase inhibitor 2A/2B (CDKN2A/CDKN2B) detected in the tumor by next gene sequencing suggests that they may play an important role in this case.

Regeneration of muscular wall of the bladder using a ureter matrix graft as a scaffold

ABSTRACT We investigated a method for bladder augmentation in rats using a decellularized ureter graft. We used 16 rats divided into two groups of eight. After partial cystectomy, the bladders in group 1 were grafted with a 1 cm2 patch of human decellularized ureter. Rats in group 2 were untreated controls. Biopsies of the graft were taken at 1, 3 and 9 months postoperatively for histological investigation. Total removal of cells and preservation of extracellular matrix (ECM) was confirmed in the decellularized ureter. Histological examination after 1 month revealed few cells at the border of the graft. Three months after the operation, the graft was infiltrated by vessels and smooth muscle and the mucosal lining was complete. All bladder wall components resembled native bladder wall by 9 months after implantation. CD34, CD31, α-smooth muscle actin, S100, cytokeratin AE1/AE3 and vimentin were detected 9 months after the operation. We demonstrated the potential of decellularized biocompatible ureteric grafts for use as a natural collagen scaffold for bladder repair in rats.

Total nephroureterocystectomy and urethrectomy due to urothelial carcinoma associated with the BK polyomavirus infection after kidney transplantation: a case report with literature review

BackgroundBK polyomavirus (BKPyV) infection after kidney transplantation is an important cause of graft failure among kidney transplant recipient and may cause malignant tumor, although the association between BKPyV infection and malignant tumor has been controversial yet.Case presentationWe report a case of a 39-year-old-male kidney transplantation (KTx) recipient with urine BKPyV replication who developed a graft pelvic tumor with the positive Simian virus 40 large T antigen (SV40 TAg). The patients received a living-related KTx from his 65-year-old mother. A protocol biopsy at 14 months after KTx showed BKPyV-associated nephropathy. Therefore, the dose of immunosuppressants was reduced, resulting in improved BKPyV viremia, but viruria persisted. About 117 months after KTx, urine cytology showed atypical cells suspicious for malignancy. Cystoscopy revealed a tumor on the neck of the bladder. Transurethral resection of the bladder tumor (TUR-BT) was performed; however, the diagnosis of malignancy was not confirmed at that time. Six months after the TUR-BT, urine cytology showed atypical cells definite for malignancy. Computed tomography and retrograde pyelography showed no evidence of urinary tract tumor and metastasis. Subsequently, total nephroureterocystectomy and urethrectomy were performed. Histological examination of the graft ureter revealed a high-grade urothelial carcinoma, with glandular differentiation, pT1. Immunohistochemically, the tumor showed positivities for SV40 TAg and p53, along with increased Ki67 labeling cells were increased. By contrast, nonneoplastic cells were negative for SV40 TAg. At the time of writing the present manuscript, the patient is free from recurrence or residual tumor and being closely monitored without additional therapy, 32 months after the surgery.ConclusionThe relationship between BKPyV infection after KTx and bladder carcinogenesis remains to be elucidated. However, when the KTx recipients who continue to have BKPyV infection for a long time are treated, the possibility of risk factors for renourinary carcinoma should always be carefully considered.

Pelvic Surgery in the Transplant Recipient: Important Considerations for the Non-transplant Surgeon.

Classically, kidney transplantation (KT) consists of heterotopic implantation of the renal graft in the iliac fossa with vascular anastomosis on the iliac vessel and reimplantation of the graft ureter in the bladder of the recipient. However, a wide range of variations exist in both vascular anastomosis and urinary diversion that the non-transplant surgeon should know. For any pelvic surgery in a KT patient, the non-transplant surgeon should preoperatively evaluate the anatomy of the graft, its vascularization and its urinary tract. The transplant ureter should be identified and secured by preoperative JJ stenting whenever needed. For any surgery, maintenance and control of both immunosuppressive treatment and renal function is crucial. The advice or even the assistance of a transplant surgeon should be required because any damage to vascularization or urinary drainage of the renal graft could have dramatic and definitive consequences on graft function.

Orthotopic ileal neobladder reconstruction in a woman who developed squamous cell carcinoma of the urinary bladder after kidney transplantation.

The case of a 62-year-old woman who developed squamous cell carcinoma of the bladder 16 years after a kidney transplant is reported here. After the transplant, immunosuppressive therapy was maintained with cyclosporin A (200 mg/day) and the patient's serum creatinine level was 0.9 mg/dL. She was diagnosed with squamous cell carcinoma of the bladder 16 years later and underwent radical cystectomy with an orthotopic ileal neobladder. The Studer technique was used and the afferent ileal loop was anastomosed to the graft ureter. The postoperative course was uneventful. At the 6-month follow-up visit, the patient showed no evidence of recurrence. Her serum creatinine level was 1.0 mg/dL. The patient was continent during the day and the night. This case shows that the construction of an orthotopic ileal neobladder after cystectomy is safe and feasible in kidney transplant recipients.

Ureteral Reconstruction in Goats Using Tissue-Engineered Templates and Subcutaneous Preimplantation.

Repair of long ureteral defects often requires long graft tissues and extensive surgery. This is associated with complications, including a lack of suitable tissue and graft site morbidity. Tissue engineering may provide an attractive alternative to the autologous graft tissues. In this study, ureteral repair using (preimplanted) tubular collagen-Vicryl templates was evaluated in a new goat model. Tubular templates were prepared from tubularized Vicryl meshes and 0.7% type-I collagen (length = 6 cm, inner diameter = 6 mm, wall thickness = 3 mm). In total, twelve goats were used and evaluated after 3 months. Eight goats were implanted with the collagen-Vicryl templates and in four goats the templates were first preimplanted in the subcutis and subsequently used as ureteral graft. Template implantation was successful in 92% of the goats(11/12). During follow-up, 82% of the animals (9/11) survived without signs of discomfort. Two animals were sacrificed prematurely due to kidney perforation by the stent and urine leakage. Two other animals presented with stenosis of the neoureter due to stent migration. After preimplantation, the templates were remodeled mostly to autologous tissue with similar mechanical characteristics as the native ureter. Goats grafted with preimplanted templates presented with predominantly healthy kidneys, whereas the goats grafted with the collagen-Vicryl templates presented with fibrotic and inflamed regions in the kidneys. The use of preimplanted tissue templates showed favorable results compared with direct functional implantation of the templates. Partial remodeling toward autologous tissue and similar mechanical characteristics likely improved the integration in the ureteral tissue. Preimplantation of tissue-engineered templates should therefore be considered when two-stage procedures using a nephrostomy catheter are indicated or when planning allows for additional time to treatment.

Transitional cell carcinoma involving graft kidney in a kidney transplant recipient: a case report

BackgroundKidney transplantation (KT) is the treatment option for patients with end stage renal disease (ESRD) to prolong survival and improve quality of life. Although the use of potent immunosuppressive agents increases graft survival in kidney transplantation recipients (KTRs), it may lead to the development of malignancy, including transitional cell carcinoma (TCC). TCC developing in the pelvis of graft kidney is very rare in KTRs.Case PresentationA 40-year-old male visited hospital with complaints of nausea, vomiting and gross hematuria. Eleven years ago, he was diagnosed ESRD of unknown origin, and received a living related KT from his father 1 year later. Radiologic findings showed a huge polypoid mass in the pelvis of graft kidney with pelvo-calyceal dilation and a 3.3 cm-sized nodule in aortocaval chain and a 2.5 cm-sized nodule in right iliac chain as TCC stage IV. Sonography-guided percutaneous needle biopsy of pelvis mass in the graft kidney revealed a low grade urothelial cell carcinoma. Radical graft nephroureterectomy was performed and histopathological diagnosis confirmed as a low grade urothelial carcinoma of graft pelvis and ureter lumen, which invaded to perirenal fat and renal parenchyma with lymphovascular presence (T3Nx). The patient started with adjuvant concurrent chemo-radiation therapy and returned to regular hemodialysis.ConclusionsWe report a rare case of TCC in the pelvis of graft kidney with already advanced disease at diagnosis in a young KTR. For the early diagnosis of TCC in KTRs, exposure history to Chinese herb or analgesics should be investigated before KT and high risk population in KTRs should be tightly performed regular postoperative surveillance for TCC and considered of less calcineurin inhibitor-based immunosuppressant protocol.

Optimal Timing for Removal of the Double-J Stent After Kidney Transplantation

BackgroundUrologic complications (UC) have gradually decreased in recent years after advanced surgical experience. The incidence of urologic complications varies between 0.22% and 30% in different medical studies. There is no routine usage of double-J stenting (DJS) during renal transplantation (RT) in the literature. It is a necessity, and optimal timing for stent removal is an important question for many transplantation centers. MethodsThis study includes 818 renal transplant patients whose ureteroneocystostomy anastomoses were completed by use of the Lich-Gregorie procedure during a 2-year period at a transplantation center. We performed 926 renal transplantations at Antalya Medical Park Hospital Renal Transplantation Center between January 2014 and January 2016. The patients were divided into four groups according to the timing of DJS removal. ResultsFor group 1, removal time for DJS was between 5 and 7 days; group 2, Removal time for DJS was between 8 and 14 days; group 3, removal time for DJS was between 15 and 21 days; and group 4, removal time for DJS was later than 22 days. The patients were divided into two groups according to removal time of stent as 5 to 14 days and >15 days. DJS was performed again in the patients whose urine output was reduced during the first 5 days after removal of the DJS, whose creatine level increased, and whose graft ureter and collecting tubules were extended as an ultrasonographic finding. ConclusionsThere is no declared optimal time for the removal of DJS. The removal time was reported between postoperative first week and 3 months in some of the reports of RT centers, according to their protocols. We emphasize that the optimal time for the removal of DJS is 14 to 21 days after RT, based on the findings of our large case report study.

Tissue Engineering of Ureteral Grafts: Preparation of Biocompatible Crosslinked Ureteral Scaffolds of Porcine Origin.

The surgical reconstruction of ureteric defects is often associated with post-operative complications and requires additional medical care. Decellularized ureters originating from porcine donors could represent an alternative therapy. Our aim was to investigate the possibility of manufacturing decellularized ureters, the characteristics of the extracellular matrix (ECM) and the biocompatibility of these grafts in vitro/in vivo after treatment with different crosslinking agents. To achieve these goals, native ureters were obtained from pigs and were decellularized. The success of decellularization and the ECM composition were characterized by (immuno)histological staining methods and a DNA-assay. In vitro: scaffolds were crosslinked either with carbodiimide (CDI), genipin (GP), glutaraldehyde, left chemically untreated or were lyophilized. Scaffolds in each group were reseeded with Caco2, LS48, 3T3 cells, or native rat smooth muscle cells (SMC). After 2 weeks, the number of ingrown cells was quantified. In vivo: crosslinked scaffolds were implanted subcutaneously into rats and the type of infiltrating cells were determined after 1, 9, and 30 days. After decellularization, scaffold morphology and composition of ECM were maintained, all cellular components were removed, DNA destroyed and strongly reduced. In vitro: GP and CDI scaffolds revealed a higher number of ingrown 3T3 and SMC cells as compared to untreated scaffolds. In vivo: at day 30, implants were predominantly infiltrated by fibroblasts and M2 anti-inflammatory macrophages. A maximum of MMP3 was observed in the CDI group at day 30. TIMP1 was below the detection limit. In this study, we demonstrated the potential of decellularization to create biocompatible porcine ureteric grafts, whereas a CDI-crosslink may facilitate the remodeling process. The use of decellularized ureteric grafts may represent a novel therapeutic method in reconstruction of ureteric defects.

1003 Evaluation of a fast-track decellularization protocol for tubularized ureteral graft tissue engineering in a rat model

1003 Evaluation of a fast-track decellularization protocol for tubularized ureteral graft tissue engineering in a rat model

BK Virus–Associated Urothelial Carcinoma of a Ureter Graft in a Renal Transplant Recipient: A Case Report

BackgroundUrothelial carcinomas of ureter grafts in renal transplant patients are rare. Here we report our experience with a case of BK virus–associated urothelial carcinoma in a ureter graft. Case ReportA 47-year-old man developed chronic renal failure secondary to diabetes mellitus and started maintenance hemodialysis in September 2007. Two months later, the patient received a renal transplant from his 70-year-old mother. The patient developed BK virus–associated nephropathy 1 year after transplantation and presented with a decline in renal function and hydronephrosis in the transplanted kidney 4 years 6 months after transplantation. Cystoscopy and retrograde pyelography revealed an irregular filling defect in the ureter graft. Cytologic diagnosis of his urine revealed a high-grade urothelial carcinoma. Computerized tomography showed a cT2 ureteral tumor and no involvement of other organs. The patient subsequently underwent a transplant nephroureterectomy with bladder cuff resection. Histopathologic findings revealed a high-grade urothelial carcinoma, pT2, in the ureter graft with SV40-positive staining. The patient was closely observed without adjuvant chemotherapy therapy and remained disease free 1 year after surgery. Renal transplant recipients with BK virus infection are at high risk of developing urologic malignancies. Close attention is necessary to diagnose post-transplantation urologica malignancies as early as possible.

Construction of Ureteral Grafts by Seeding Bone Marrow Mesenchymal Stem Cells and Smooth Muscle Cells Into Bladder Acellular Matrix

BackgroundCongenital or acquired abnormalities may cause an ureteral injury or defect. The main methods to reconstruct a long ureter often cause serious complications. In this study, we sought to construct a tissue-engineered graft by seeding bone marrow mesenchymal stem cells (MSCs) and smooth muscle cells (SMCs) into a bladder acellular matrix (BAM) for ureteral reconstruction. MethodsIsolated, proliferated, and in vitro identified rabbit bone marrow MSCs and SMCs were seeded into BAM as the experimental group. Grafts only seeding SMCs were the control group. Cell-seeded grafts were used to construct tissue-engineered tubular grafts (TETG) for transplantation into the rabbit's omentum for 2 weeks before ureteral reconstruction. Evolutionary histology was performed at 2, 4, 8, and 16 weeks postoperatively. Renal function and ureteral obstruction were evaluated using intravenous urography at 16 weeks. ResultsFlow cytometry demonstrated bone marrow MSCs to express CD29, CD44, CD90, but not CD34. Histological examination revealed consistent regeneration of TETG urothelium in the experimental group. At 8 and 16 weeks after TETG grafting in vivo, multilayer urothelium covered the entire lumen with visible neovascularization within the center. Organized smooth muscle bundles were observed. Intravenous urography demonstrated no ureteral stricture or hydronephrosis. The 5 rabbits were dead within 4 weeks postoperatively. Autopsy showed scar formation inside the graft with severe hydronephrosis. ConclusionWe successfully constructed a TETG by seeding bone marrow MSCs and SMCs into BAM for ureteral reconstruction. Thus bone marrow MSCs can potentially promote urothelial regeneration to achieve a tissue-engineered ureter.

Tissue engineering of ureteral grafts by seeding urothelial differentiated hADSCs onto biodegradable ureteral scaffolds

The study is aimed to evaluate the differentiation potential of human adipose-derived stem cells (hADSCs) into urothelial lineage, and to assess possibility of constructing ureteral grafts using the differentiated hADSCs and a novel polylactic acid (PLA)/collagen scaffolds. HADSCs were indirectly cocultured with urothelial cells in a transwell coculture system for urothelial differentiation. After 14 days coculturing, differentiation was evaluated by detecting urothelial lineage markers (cytokeratin-18 and uroplakin 2) in mRNA and protein level. Then the differentiated hADSCs were seeded onto PLA/collagen ureteral scaffolds and cultured in vitro for 1 week. The biocompatibility of the scaffolds was tested by scanning electron microscopy (SEM) and MTT analysis. At last, the cell/scafflod grafts were subcutaneously implanted into 4-week-old female athymic mice for 14 days. The results demonstrated that the hADSCs could be efficiently induced into urothelial lineage by indirect coculture. The differentiated cells seeded onto the PLA/collagen ureteral scaffolds survived up to 7 days and maintained proliferation in vitro, which indicated that the scaffolds displayed good biocompatibility. In vivo study showed that the differentiated cells in the grafts survived, formed multiple layers on the scaffolds and expressed urothelial lineage markers. In conclusion, hADSCs may serve as an alternative cell resource in cell-based tissue engineering for ureteral reconstruction. These cells could be employed to construct a model of ureteral engineering grafts and be effectively applied in vivo, which could be a new strategy on ureteral replacement with applicable potential in clinical research.

Urothelial Cancer After Renal Transplantation: An Update

According to the Australian and New Zealand Dialysis and Transplantation (ANZDATA) 2010 Annual Report, cancer is surpassing cardiovascular diseases as the leading cause of posttransplantation death. Skin cancer and posttransplantation lymphoproliferative disorder (PTLD) are 2 cancers in Western countries. However, urothelial cancer happens much more frequently among Chinese people. We reviewed our experience in Congress of the Asian Society of Transplantation (CAST) 2005, including 10 urothelial cancers, among 620 renal transplant recipients. In this report, we have presented our updated data. From July 1981 to May 2011, we performed 770 renal transplantations followed by graft and native kidney sonography annually even among asymptomatic cases using the protocol described in CAST 2005. During this period, 35 urothelial tumors were detected, ie, 25 new cases were identified in 6 years. These 35 cases included 7 cases with bilateral upper tract involvement and 5 of them with bladder tumors. Seven patients had bladder cancer alone. In 19 patients, 22 ureteral cancers included 1 that grew from the graft ureter, 17 (77.3%) patients showed hydronephrosis by sonography. We performed 13 bilateral nephroureterectomies; 2 were known to have bilateral upper tract cancer. Four of the other 11 were found to have insidious tumors. In contrast, 2 of the 15 initial unilateral nephroureterectomy patients underwent a subsequent contralateral nephroureterectomy due to a tumor. The pattern of urethral cancer in renal transplant recipients is thoroughly different, including female predominance, and a higher incidence of upper tract involvement. We emphasize the necessity of routine periodic sonographic survey even among asymptomatic patients for early detection of a urothelial tumor.

Ureteral Reconstruction Using Autologous Tubular Grafts for the Management of Ureteral Strictures and Defects: An Experimental Study

Objective: To investigate whether the peritoneal cavity could function as a bioreactor to produce autologous tubular grafts for ureteral reconstruction in beagles. Materials and Methods: 8-Fr Silastic tubes were implanted into the peritoneal cavities of 6 female beagles. At 3 weeks, the tubes were harvested and the tubular tissue covering the tubes was gently everted. A segment 3 cm in length of the right mid-ureter, involving two thirds of its diameter, was removed parallel to the ureteral axis, leaving a third of the ureteral wall. A 5-Fr double-J stent was inserted into the ureter through the created defect, and two thirds of the graft were anastomosed to both edges of the ureteral defect. One third of the graft was overlapped with the retained normal ureter and anastomosed to the external surface of the lumens. Thus, the graft was partly encapsulated by the remainder of ureteral wall. The stent was maintained for 6 weeks and removed. Excretory urography was performed at 8 (n = 3) and 12 weeks (n = 3), postoperatively. Meanwhile, the neoureter was harvested and analyzed. The left ureter served as the control and a simple intubated ureterotomy was performed. Results: Histological analysis of the tubular tissue demonstrated transversely arranged myofibroblasts and an outer layer of mesothelium. The tissue was easily everted and transplanted as a ureteral graft. Eight weeks postoperatively, the neoureter demonstrated normal ureteral architecture, composed of multilayers of urothelium surrounded by smooth muscle bundles, which became increasingly organized with time. Excretory urography indicated no stenosis or hydronephrosis. Conclusions: These results show that autologous tubular tissue grown within the recipients’ peritoneal cavity can be used for ureteral reconstruction in the beagle model.