Vesicoureteral Reflux in Kidney Transplantation

Evaluation of two nephrocystostomy techniques for ureteral bypass in cats

OBJECTIVE

To describe two techniques for nephrocystostomy (NCT) in cats.

STUDY DESIGN

Experimental study.

ANIMALS

Twelve, adult, purpose-bred, cats.

METHODS

A simple NCT (n = 3) or bladder cuff NCT (n = 9) was performed in the right or left kidneys. For simple NCT, an 8F catheter was placed through the caudal pole into the renal pelvis and the bladder was sutured around the catheter. For bladder cuff NCT, a 6 mm defect was removed from the caudal pole and a cuff of bladder mucosa was advanced and sutured into the renal pelvis. A 10F catheter was placed through the defect into the renal pelvis and the bladder wall was sutured around the catheter. Catheters were removed 41-118 days post-surgery. Computed tomography (CT) was performed 25 days after catheter removal for the simple NCT and 30 (n = 6) and 90 (n = 3) days after catheter removal for bladder cuff NCT. Histological evaluation of the nephrocystostomy site was performed.

RESULTS

All simple NCTs became obstructed after catheter removal. All bladder cuff NCTs were patent, and CT revealed contrast flow into the bladder. Hematuria, clot-associated urethral obstruction, catheter dislodgement, and bladder infection occurred variably after surgery. Histological findings consisted of smooth epithelialization of the NCT and degenerative changes in the caudal pole of the kidney.

CONCLUSION

Bladder cuff NCT was feasible in normal cats and remained patent for 90 days. Methods to limit nephrostomy track hemorrhage should be investigated. Degenerative changes may be related to vascular impairment from the bladder cuff sutures.

CLINICAL SIGNIFICANCE

Complete ureteral bypass was possible in cats using only native tissues.

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

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

THE AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Vesicoureteral reflux treatment following kidney transplantation potentially prevents graft function deterioration and allows long-term graft survival

OBJECTIVES

The impact of vesicoureteral reflux post-kidney transplantation on graft survival remains unclear, and guidelines on appropriate vesicoureteral reflux management post-kidney transplantation are lacking. For this reason, we conducted a retrospective study on the impact of vesicoureteral reflux and its treatment on graft survival.

METHODS

We evaluated 347 consecutive kidney transplantation recipients, who also underwent a ureteroneocystostomy, between 1996 and 2012.

RESULTS

Vesicoureteral reflux was diagnosed in 55 cases (15.9%), with a median post-kidney transplantation duration of 50 months (range 0-172 months). Among these, 22 were monitored, 17 underwent transurethral collagen injections, and 16 received a ureteroneocystostomy. The 10-year graft survival rate was significantly lower in recipients with vesicoureteral reflux (68.9%) than in those without vesicoureteral reflux (84.4%) (P = 0.0165). Moreover, among the vesicoureteral reflux recipients, the 10-year graft survival rate was significantly higher in those whose vesicoureteral reflux was cured (80.1%) than in those whose vesicoureteral reflux persisted (53.6%) (P = 0.0062). Multivariate analysis showed that vesicoureteral reflux was significantly associated with both overall and death-censored graft loss (odds ratio 3.737 and 3.685; P = 0.0015 and P = 0.0052, respectively). Lastly, the incidence of interstitial fibrosis and tubular atrophy was higher in recipients with vesicoureteral reflux than in those without vesicoureteral reflux (P = 0.0009).

CONCLUSIONS

Post-kidney transplantation vesicoureteral reflux has a negative impact on long-term graft survival, and that treatment prevents graft deterioration. From the perspective of maintaining long-term graft function in kidney recipients, vesicoureteral reflux may be one of the most important complications to be addressed.

Long-term outcome of non-antireflux robotic-assisted laparoscopic ureter reimplantation in ureteral obstruction

PURPOSE

Although robotic-assisted laparoscopic ureter reimplantation (RALUR) is a recognized alternative to open and laparoscopic ureter reimplantation in treating distal ureteral obstruction, there are limited data on long-term efficacy and safety outcomes of non-antireflux RALUR. We assessed patients undergoing RALUR, evaluating operative, functional and safety determinants.

MATERIALS AND METHODS

All consecutive patients undergoing non-antireflux RALUR between April 2015 and January 2020 were included in this retrospective cohort study. The primary outcome endpoint was recurrent distal ureteral obstruction.

RESULTS

Mean follow-up was 41.3 months (CI 95%, 33.3-49.2). Among the 26 included patients, none developed recurrent distal ureteral obstruction. Kidney function in terms of serum creatinine level (72.0 vs. 71.0 µmol/L, p=0.988) and glomerular filtration rate (92.0 vs. 91.0 mL/min, p=0.831) was stable between the preoperative period and the last follow-up. Renal pelvis dilatation decreased significantly postoperatively, from grade 2 to grade 0 (p<0.001). Most patients (73.1%) remained free from any clinical symptoms of reflux during the follow-up. The rate of postoperative complications (Clavien-Dindo grade ≥II) was 23.1%. All complications resolved without sequelae. No recurring urinary tract infections were reported.

CONCLUSIONS

Non-antireflux RALUR appears to be safe and effective in the management of distal ureteral obstruction. There was no recurrent ureteral obstruction after RALUR in our cohort during a mean follow-up of more than 3 years. Non-antireflux reimplantation did not seem to have any notable impact on renal function during the follow-up period.

Kidney transplantation from expanded criteria donors: an increased risk of urinary complications - the UriNary Complications Of Renal Transplant (UNyCORT) study

OBJECTIVES

To assess the impact of expanded criteria donors (ECD) on urinary complications in kidney transplantation.

PATIENTS AND METHODS

The UriNary Complications Of Renal Transplant (UNyCORT) is a cohort study based on the French prospective Données Informatisées et VAlidées en Transplantation/Computerized and VAlidated Data in Transplantation (DIVAT) cohort. Data were extracted between 1 January 2002 and 1 January 2018 with 1-year minimum follow-up, in relation to 44 pre- and postoperative variables. ECD status was included according to United Network for Organ Sharing (UNOS) definition. The primary outcome of the UNyCORT study was the association between the donor's ECD/standard criteria donors (SCD) status and urinary complications at 1 year in uni- and multivariate analysis. Sub-group analysis, stratified analysis on ECD/SCD donor's status and transplant failure analysis were then conducted.

RESULTS

Between 1 January 2002 and 1 January 2018, 10 279 kidney transplants in adult recipients were recorded within the DIVAT network. A total of 8559 (83.4%) donors were deceased donors and 1699 (16.6%) were living donors (LD). Among donation after circulatory death (DCD) donors, 224 (2.85%) were uncontrolled DCD and 93 (1.09%) were controlled DCD donors. A total of 3617 (43.9%) deceased donors were ECD. The overall urological complication rate was 16.26%. The donor's ECD status was significantly associated with an increased risk of urological complications at 1 year in multivariate analysis (odds ratio: 1.50, 95% CI 1.31-1.71; P < 0.001) and especially with stenosis and ureteric fistulae at 1 year. There is no association with LD, uncontrolled and controlled DCD. The placement of an endo-ureteric stent was beneficial in preventing urinary complications in all donors and particularly in ECD donors.

CONCLUSION

The donor's ECD status is associated with a higher likelihood of stenosis and ureteric fistulae at 1 year. Recipients of grafts from ECD donors should probably be considered for closer urological monitoring and systematic preventive measures.

Robot-assisted Transplant Ureteral Repair to Treat Transplant Ureteral Strictures in Patients after Robot-assisted Kidney Transplant: A Case Series

OBJECTIVE

To describe the use of robotic-assisted transplant ureteral repair (RATUR) for treating transplant ureteral stricture (TUS) in 3 patients who had undergone robot assisted kidney transplant (RAKT).

METHOD

We reviewed the medical records of 3 patients who experienced TUS after RAKT and who underwent RATUR between 2017 and 2020. The patients' RAKT, post-transplant clinical course, endourological interventions, reoperation, and recovery were assessed.

RESULTS

All patients diagnosed with TUS presented with deterioration of kidney function after RAKT. Method of diagnosis included ultrasound, antegrade ureterogram, and CT scan. All 3 patients had a short (<1 cm) area of TUS and underwent RATUR. For 2 patients, distal strictures were bypassed with modified Lich-Gregoir ureteroneocystostomy reimplantation. One patient was treated with pyelo-ureterostomy to the contralateral native ureter. No intraoperative complications, conversions to open surgery, or significant operative blood loss requiring blood transfusion for any patient were observed. Also, no patients had urine leaks in the immediate or late postoperative period. After RATUR, 2 patients developed Clavien grade II complications with rectus hematoma or urinary tract infection.

CONCLUSION

RATUR is a technically feasible operation for kidney transplant patients with TUS after RAKT. This procedure may provide the same benefits of open operation without promoting certain comorbidities that may occur from open surgical procedures.

Minimal-invasive management of urological complications after kidney transplantation

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

Update on the Management of Urological Problems Following Kidney Transplantation

Urological problems in kidney transplant recipients are not limited only to posttransplantation urological complications. These problems are a cause of significant patient mortality and morbidity that have wide-ranging effects on graft survival throughout the entire life of the graft. Ultimately, the transplant comprises a major portion of the urinary system; therefore, the transplant team should be prepared for foreseeable and unforeseeable urological problems in the short and long terms. These mainly include postoperative urological complications (urine leakage, ureteral stenosis, and vesicoureteral reflux), bladder outlet obstruction, and graft urolithiasis. In recent years, significant advances have been made in the management of urological complications, especially due to advances in endourologic interventions. The aim of this review is to summarize the management of urological problems after kidney transplantation in the context of the current literature.

Results of a previously unreported extravesical ureteroneocystostomy technique without ureteral stenting in 500 consecutive kidney transplant recipients

Urologic complications can still occur following kidney transplantation, sometimes requiring multiple radiological and/or surgical procedures to fully correct the problem. Previously proposed extravesical ureteral reimplantation techniques still carry non-negligible risks of the patient developing urologic complications. About 10 years ago, a new set of modifications to the Lich-Gregoir technique was developed at our center, with the goal of further minimizing the occurrence of urologic complications, and without the need for initial ureteral stent placement. It was believed that an improvement in the surgical technique to minimize the risk of developing urologic complications was possible without the need for stent placement at the time of transplant. In this report, we describe the advantages of this technique (i.e., mobilized bladder, longer spatulation of the ureter, inclusion of bladder mucosa with detrusor muscle layer in the ureteral anastomosis, and use of a right angle clamp in the ureteral orifice to ensure that it does not become stenosed). We also retrospectively report our experience in using this technique among 500 consecutive (prospectively followed) kidney transplant recipients transplanted at our center since 2014. During the first 12mo post-transplant, only 1.4%(7/500) of patients developed a urologic complication; additionally, only 1.0%(5/500) required surgical repair of their original ureteroneocystostomy. Five patients(1.0%) developed a urinary leak, with 3/5 having distal ureteral necrosis, and 1/5 subsequently developing a ureteral stricture. Two other patients developed ureteral stenosis, one due to stricture and one due to ureteral stones. These overall results are excellent when compared with other reports in the literature, especially those in which routine stenting was performed. In summary, we believe that the advantages in using this modified extravesical ureteroneocystostomy technique clearly help in lowering the early post-transplant risk of developing urologic complications. Importantly, these results were achieved without the need for ureteral stent placement at the time of transplant.

Egyptian clinical practice guideline for kidney transplantation

Objective: To present the first Egyptian clinical practice guideline for kidney transplantation (KT).

Methods: A panel of multidisciplinary subspecialties related to KT prepared this document. The sources of information included updates of six international guidelines, and review of several relevant international and Egyptian publications. All statements were graded according to the strength of clinical practice recommendation and the level of evidence. All recommendations were discussed by the panel members who represented most of the licensed Egyptian centres practicing KT.

Results: Recommendations were given on preparation, surgical techniques and surgical complications of both donors and recipients. A special emphasis was made on the recipient’s journey with immunosuppression. It starts with setting the scene by covering the donor and recipient evaluations, medicolegal requirements, recipient’s protective vaccines, and risk assessment. It spans desensitisation and induction strategies to surgical approach and potential complications, options of maintenance immunosuppression, updated treatment of acute rejection and chemoprophylactic protocols. It ends with monitoring for potential complications of the recipient’s suppressed immunity and the short- and long-term complications of immunosuppressive drugs. It highlights the importance of individualisation of immunosuppression strategies consistent with pre-KT risk assessment. It emphasises the all-important role of anti-human leucocyte antigen antibodies, particularly the donor-specific antibodies (DSAs), in acute and chronic rejection, and eventual graft and patient survival. It addresses the place of DSAs across the recipient’s journey with his/her gift of life.

Conclusion: This guideline introduces the first proposed standard of good clinical practice in the field of KT in Egypt.

Abbreviations: Ab: antibody; ABMR: Ab-mediated rejection; ABO: ABO blood groups; BKV: BK polyomavirus; BMI: body mass index; BTS: British Transplantation Society; CAN: chronic allograft nephropathy; CDC: complement-dependent cytotoxicity; CKD: chronic kidney disease; CMV: cytomegalovirus; CNI: calcineurin inhibitor; CPRA: Calculated Panel Reactive Antibodies; (dn)DSA: (de novo) donor-specific antibodies; ECG: electrocardiogram; ESWL: extracorporeal shockwave lithotripsy; FCM: flow cytometry; GBM: glomerular basement membrane; GN: glomerulonephritis; HIV: human immunodeficiency virus; HLA: human leucocyte antigen; HPV: human papilloma virus; IL2-RA: interleukin-2 receptor antagonist; IVIg: intravenous immunoglobulin; KT(C)(R): kidney transplantation/transplant (candidate) (recipient); (L)(O)LDN: (laparoscopic) (open) live-donor nephrectomy; MBD: metabolic bone disease; MCS: Mean channel shift (in FCM-XM); MFI: mean fluorescence intensity; MMF: mycophenolate mofetil; mTOR(i): mammalian target of rapamycin (inhibitor); NG: ‘not graded’; PAP: Papanicolaou smear; PCN: percutaneous nephrostomy; PCNL: percutaneous nephrolithotomy; PKTU: post-KT urolithiasis; PLEX: plasma exchange; PRA: panel reactive antibodies; PSI: proliferation signal inhibitor; PTA: percutaneous transluminal angioplasty; RAS: renal artery stenosis; RAT: renal artery thrombosis;:rATG: rabbit anti-thymocyte globulin; RCT: randomised controlled trial; RIS: Relative MFI Score; RVT: renal vein thrombosis; TB: tuberculosis; TCMR: T-cell-mediated rejection; URS: ureterorenoscopy; (CD)US: (colour Doppler) ultrasonography; VCUG: voiding cystourethrogram; XM: cross match; ZN: Ziehl–Neelsen stain

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

BACKGROUND

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

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

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

Endoscopic treatment of symptomatic VUR disease after the renal transplantation: analysis of 49 cases

BACKGROUND

To evaluate the outcome of endoscopic treatment for symptomatic vesicoureteral reflux (VUR) disease in renal transplantation patients and to determine the factors that were associated with the success rate of the treatment.

METHODS

A total of 121 symptomatic VUR diseases diagnosed between 2014 and 2018 in 3560 renal transplant patients. The results of 49 VUR cases that presented with febrile urinary tract infection (UTI) and were hospitalized for antibiotic treatment were included in the study. Reflux was detected by voiding cystourethrogram and treatment was performed by endoscopic Deflux® injection. The result of endoscopic treatment was evaluated clinically by 3 months periods.

RESULTS

The mean time between transplantation and endoscopic treatment was 59.6 (5-132) months, and the mean follow-up period after the endoscopic treatment was 14 (6-48) months, respectively. The success rate after the first injection was 59.1% (n = 29) and 67.3% (n = 33) after the second injection. One patient developed anuria, one patient febrile UTI and four patients developed minimal macroscopic hematuria after the procedure.

CONCLUSIONS

Endoscopic treatment of symptomatic VUR in transplanted kidney is a safe and feasible procedure. The amount of bulking agent or duration between the transplantation and diagnosis of VUR does not have any impact on the success of the treatment. However, the younger age of the patients and the female gender seem to have a positive effect on the outcome of the procedure.

Comparing treatment modalities for transplant kidney vesicoureteral reflux in the pediatric population

INTRODUCTION

Non-refluxing ureteral reimplantation is favored in pediatric renal transplantation to prevent complications, such as vesicoureteral reflux (VUR) in the transplant ureter. VUR resulting in febrile urinary tract infections remains a problem in this population, leading to repeated hospitalizations and increased morbidity. Revision of the vesicoureteral anastomosis can be a surgical challenge due to scar tissue and tenuous vascularity of the transplant ureter. Therefore, alternative options such as endoscopic injection of Deflux at the neo-orifice and surveillance with prophylactic antibiotics have emerged as potential treatment modalities for transplant ureter VUR.

OBJECTIVE

The authors reviewed their experience of the management of VUR in the transplant ureter, comparing outcomes of various modalities.

STUDY DESIGN

With Institutional Review Board approval, a retrospective chart review of all renal transplant patients from January 2002 to January 2017 was conducted. All patients with VUR on voiding cystourethrogram (VCUG) after surgery were identified. Indications for end-stage renal disease, urologic comorbidities, pretransplant VCUG, and operative details were recorded. After transplantation, febrile urinary tract infections, ultrasound findings, and any further interventions-surveillance, subureteral endoscopic injection of Deflux, or ureteral reimplantation-were documented along with their outcomes.

RESULTS

Overall, VUR was identified in 35/285 (12.3%) transplant patients after a non-refluxing ureteroneocystostomy. VUR was managed with surveillance in 17/35 (49%), intravesical Deflux injection in 11/35 (31%), and immediate redo ureteral reimplantation in 7/35 (20%). Ten out of 11 patients undergoing Deflux injection had a postoperative VCUG. All patients developed VUR recurrence; the majority showed immediate failure and only 1/10 showed late recurrence. Of the immediate failures, 3/9 patients were maintained on prophylactic antibiotics, and 6/9 patients underwent ureteral reimplantation. In these six patients undergoing reimplantation after failed Deflux, 3/6 (50%) patients required additional surgeries: One patient developed recurrence of reflux and two patients developed ureterovesical junction obstruction. In contrast, no complications were seen in patients undergoing primary ureteral reimplantation.

DISCUSSION

The study is limited by low numbers and a retrospective design. However, the results of this study differ significantly from the published Deflux series showing a success rate of more than 50% in the treatment of transplant kidney VUR. In fact, post-Deflux redo ureteral reimplantation was associated with an increased risk of postoperative complication.

CONCLUSION

The use of Deflux in the post-transplant setting has poor results. In the study series, 11/11 patients demonstrated clinical and radiographic failure. Therefore, as an institution the authors do not recommend Deflux as first-line treatment of VUR in the transplant patient.

Unexpected Vesicoureteral Reflux Into a Nonfunctioning Transplant Kidney on Renal Scintigraphy

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