Transurethral injection therapy with dextranomer/hyaluronic acid copolymer (Deflux) for treatment of secondary vesicoureteral reflux after renal transplantation

A systematic review of outcomes of Deflux® treatment for vesicoureteral reflux following pediatric renal transplantation

INTRODUCTION

Vesicoureteral reflux (VUR) after renal transplant in the pediatric population may be associated with an increased incidence of urinary tract infection (UTIs) leading to increased morbidity, including graft dysfunction and graft loss. The non-orthotopic location of the transplanted ureter, and lack of submucosal tunnel may pose challenges in correcting the VUR using endoscopic injection techniques. Herein we report the results of a systematic review evaluating the outcomes of endoscopic treatment of VUR using Deflux® in this population.

METHODS

Pubmed and Embase databases were searched from October 2001 to April 2019. Full-text English articles involving patients less than 18 years old at the time of transplant, with a diagnosis of VUR post-transplantation, who underwent Deflux® treatment were included. Figure 1 outlines our PRISMA-compliant search strategy.

RESULTS

We found 6 eligible studies describing Deflux® treatment outcomes in 67 pediatric patients with post-transplant VUR where voiding cystourethrogram (VCUG) confirmed the diagnosis and resolution of VUR. The mean success rate was 36.8%. Ureteral obstruction occurred in 7/67 cases (10.4%). In all these 7 cases of obstruction, ureteric stenting was the initial management, but was only successful in 1 patient. Open ureteroneocystostomy (UNC) was performed in 4/7 cases, while 2/7 were managed expectantly (unknown outcomes). Persistent VUR with UTI despite Deflux® were reported in 20 out of 67 cases. Of these, 7 were managed with prophylactic antibiotics, and 13 with UNC. Success rates were consistently low for UNC after failed Deflux® in comparison to redo UNC in transplant ureters without prior injection.

CONCLUSION

Low success rates are seen following injection techniques for VUR after pediatric renal transplant. Although an appealing option, Deflux® may prove counterintuitive due to the high rate of obstruction and suboptimal results if open reimplantation is required. A multi-institutional prospective study with a larger population size may further elucidate these results.

Treatment of Vesicoureteral Reflux Detected After Renal Transplant in Pediatric Patients: A Single-Center Experience

OBJECTIVE

In children who undergo renal transplant, vesicoureteral reflux on the transplanted kidney is a serious complication that may result in organ loss. In this study, we aimed to evaluate the results of endoscopic and open surgical techniques in the treatment of patients with recurrent urinary tract infections and vesicoureteral reflux after renal transplant.

MATERIAL AND METHODS

The files of pediatric patients who underwent renal transplant in our hospital between January 2016 and January 2019 were evaluated retrospectively. In this single-center analysis, we investigated the incidence of vesicoureteral reflux in the kidney transplant recipients and the results of various approaches to treat it.

RESULTS

Eighty pediatric patients underwent renal transplant between January 2016 and January 2019. Fourteen of those patients (17.5%, 7 female and 7 male) were diagnosed with vesicoureteral reflux in the postoperative period. Twelve of 14 patients received endoscopic injections as the first treatment. Clinical or radiological success was achieved in 5 patients (5 of 15 injection treatments, 33%); in 4 patients (4/12, 33.3%) success was after the first endoscopic injection treatment, and in 1 patient (1/3, 33.3%) success was after the second injection. Meanwhile, clinical or radiological success was achieved in 6 of 7 patients who underwent redo ureteroneocystostomy (6/7, 85.7%).

CONCLUSION

Although symptomatic vesicoureteral reflux after renal transplant is rare in pediatric patients, it is an important cause of morbidity as it requires recurrent surgical procedures. Although endoscopic treatment is safe and minimally invasive, the success rate is lower than expected, and redo of ureteral reimplant may be required in most cases.

The Efficiency and Safety of Endoscopic Treatment on Kidney-Transplanted Patients With Symptomatic Vesicoureteral Reflux in Native and Transplanted Renal Units

OBJECTIVES

To evaluate the outcome of endoscopic treatment of symptomatic vesicoureteral reflux (VUR) in patients with VUR in both transplanted and native renal units.

MATERIAL AND METHODS

Between January 2014 and December 2019, 23 transplanted patients with symptomatic VUR with reflux in both transplanted and native kidney were included in the study. All patients were patients with a history of kidney failure due to reflux nephropathy. A voiding cystourethrography was performed after at least 1 episode of acute glomerulo pyelonephritis or deterioration of the graft function. All patients underwent a urine culture and an ultrasonic evaluation preoperatively. A dextranomer/hyaluronic acid bulking agent was injected via endoscope by a rigid metal needle around a double J stent. Clinical success was defined as absent of febrile urinary tract infection during the follow-up period.

RESULTS

The procedure was applied in 52 effected renal units; of these, 27 were transplanted kidneys, and 25 were native kidneys. Overall clinical success was achieved in 69.6% (N = 16) of patients. The success rate after the first procedure was 52.2% (N = 12), whereas 17.3% (N = 4) achieved success after the second treatment. No intraoperative complications occurred throughout the endoscopic procedure. Minor postoperative complications included 2 (10%) cases of self-limiting episodes of hematuria that did not require intervention.

CONCLUSION

Endoscopic treatment of symptomatic VUR for both transplanted ureter and native ureter is a safe treatment in most of the patients. Therefore, endoscopic ureteral injection is a treatment modality with low morbidity that should be preferred to open surgery as first-line treatment in this subgroup of patients.

Efficiency and Safety of the Sting Operation on Kidney Transplanted Patients with Symptomatic Vesicoureteral Reflux and Neurogenic Bladder Dysfunction

PURPOSE

The study aimed to evaluate the feasibility and effectiveness of the endoscopic treatment in transplanted patients with neurogenic bladder who complained of symptomatic vesicoureteral reflux (VUR).

MATERIAL AND METHODS

Fifteen patients with VUR who were previously diagnosed with a neurogenic bladder were included in the study. The Lich-Gregoire technique was used for ureterovesical anastomosis during transplantation, and a double J stent was inserted routinely in the ureter to protect the anastomosis. The sting operation was performed under general anesthesia in the lithotomy position. A 4.8 Fr double J stent (Boston Scientific, Boston, MA) was inserted to prevent the risk of ureteral obstruction. Successful treatment was defined as absent acute glomerulopyelonephritis (AGPN) during follow-up and as absent VUR on radiological evaluation.

RESULTS

Clinical success was achieved in 6 of 10 patients (60%) who presented with recurrent febrile urinary tract infection (UTI) and in 4 of 6 (66%) patients who presented with gradually graft function deterioration. In 3 patients, the ureteral neo-orifice could not be localized during the operation owing to severe trabeculation of the bladder wall. The other 2 patients with a previous history of augmented bladder procedures had a hypotension attack during bladder filling; hence, the operation was stopped to prevent further complications. Two patients, whose clinical symptoms did not resolve after the sting procedure, accepted open ureteral reimplantation surgery.

CONCLUSION

Endoscopic management of the VUR in the transplant patients with neurogenic bladder function is safe and effective in at least half of the patients in a mid-term follow-up period.

Endoscopic Treatment for Post-Transplant Vesicoureteral Reflux

INTRODUCTION

Vesicoureteral reflux (VUR) is one of the most common ureteric complications after kidney transplantation that might cause symptomatic infections which deteriorate graft function. Surgical reimplantation has been the standard treatment; recently, endoscopic injection has been an alternative approach. We report our endoscopic treatment results and analyze the long-term outcome, even in patients with less optimal graft function.

MATERIALS AND METHODS

A total of 16 patients and 19 symptomatic VUR were diagnosed at mean time of 88.3 months after their transplantation. The distribution of VUR grade was 1, 2, 8, 6, and 2 for grade I to V, respectively, with a mean VUR grade of 3.26 according to their voiding cystourethrogram images. Endoscopic Deflux injections were performed by a single urologist via rigid cystoscope with a beveled needle system. They were followed monthly thereafter.

RESULT

The average number of admissions due to symptomatic urinary tract infection was 2.68/person, and the mean creatinine level before endoscopic treatment was 1.63 mg/dL. The amount of Deflux injection was 0.7 to 1.2 mL per affected ureter; the mean creatinine level after endoscopic treatment was 1.41 mg/dL. The eGFR remained stationary in both eGFR > 60 and eGFR < 60 mL/min groups with a clinical success rate of 75% in both groups.

CONCLUSION

Endoscopic dextranomer-hyaluronic acid injection is a safe and feasible treatment option for VUR after kidney transplantation. Our data showed its efficacy in recipients whose eGFR is less than 60 mL/min.

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.

Urologic Evaluation and Management of Pediatric Kidney Transplant Patients

Urologic causes of end-stage renal disease are estimated between 25% and 40% of causes. The goal of renal transplantation in chronic kidney disease patients is to provide renal replacement therapy with less morbidity, better quality of life, and improved overall survival compared with dialysis. A patient's urologic history can be a significant source of problems related to infections, recurrence of disease, and surgical complications. Many of the urologic risks are modifiable. Proper evaluation and management can mitigate the potential problems after transplantation, and these patients with complex urologic problems are seen to have similar graft function outcomes.

Endoscopic antireflux surgery leading to obstruction in pediatric renal transplant patients

To describe a multicenter experience with management of ureteral obstruction after injection of Dx/HA for VUR in pediatric renal transplant patients. The records of all pediatric renal transplant patients who underwent Dx/HA injection for VUR and had subsequent obstruction were identified, and the management and outcomes were reviewed. Follow-up ranged from 1 to 10 years. There were four patients identified, all of whom had a history of rising creatinine, recurrent UTI, and increasing hydronephrosis which led to the diagnosis of high-grade VUR. Obstruction was diagnosed within 24-72 hours after injection in three patients. One patient was asymptomatic, and rising creatinine and hydronephrosis were noted 1 month after injection. One patient was managed expectantly, while three patients underwent ureteral stent placement. After the stent was removed, one patient went on to open reimplant due to delayed obstruction, the second patient with voiding dysfunction is currently managed with an indwelling ureteral stent and may require further definitive surgery, the third patient recovered, and the fourth is being observed. Our cases illustrate that despite initial successful management of the obstruction in some, delayed obstruction is possible and may necessitate open reimplant. It is imperative that these patients have close follow-up after Dx/HA.

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.

Diagnosis and management of ureteral complications following renal transplantation

When compared with maintenance dialysis, renal transplantation affords patients with end-stage renal disease better long-term survival and a better quality of life. Approximately 9% of patients will develop a major urologic complication following kidney transplantation. Ureteral complications are most common and include obstruction (intrinsic and extrinsic), urine leak and vesicoureteral reflux. Ureterovesical anastomotic strictures result from technical error or ureteral ischemia. Balloon dilation or endoureterotomy may be considered for short, low-grade strictures, but open reconstruction is associated with higher success rates. Urine leak usually occurs in the early postoperative period. Nearly 60% of patients can be successfully managed with a pelvic drain and urinary decompression (nephrostomy tube, ureteral stent, and indwelling bladder catheter). Proximal, large-volume, or leaks that persist despite urinary diversion, require open repair. Vesicoureteral reflux is common following transplantation. Patients with recurrent pyelonephritis despite antimicrobial prophylaxis require surgical treatment. Deflux injection may be considered in recipients with low-grade disease. Grade IV and V reflux are best managed with open reconstruction.

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.

Ureteral obstruction following injection of dextranomer/hyaluronic acid copolymer: an infrequent but relevant complication

PURPOSE

To report our experience with ureteral obstruction after injection of dextranomer/hyaluronic acid copolymer (Dx/Ha) to treat vesicoureteral reflux, and analyze its possible causes, management and outcome.

MATERIALS AND METHODS

Retrospective review of patients undergoing injection of Dx/Ha. The charts of patients with clinically relevant ureteral obstruction were evaluated for indications, prior interventions, technique of injection and volume injected. Video recordings obtained during injection were analyzed to detect possible technical errors.

RESULTS

Fifty-four patients (87 ureters) were treated with Dx/Ha injection in a 5-year period. Five ureters (5.7%) in five patients (9.3%) developed significant ureteral obstruction requiring intervention. Manifestations of obstruction included pain in two patients, urinary tract infections in one and loss of function in one. Increased serum creatinine was observed in a patient with a transplanted kidney. Four obstructions resolved spontaneously (two after percutaneous nephrostomy, two after placement of a ureteral stent) and one required reimplantation. Review of the videos did not reveal any deviation from the usual technique. The volumes injected in the obstructed cases (0.7-1.2 ml) were in the usual range.

CONCLUSIONS

In this series, the incidence of post Dx/Ha ureteral obstruction was higher than previously reported. Although 4/5 cases resolved spontaneously, they required drainage to relieve symptoms or to improve renal function. Surgeons need to be aware of this complication and include its possible occurrence in the informed consent obtained prior to injection.

Endoscopic vesicoureteral reflux correction in transplanted kidneys: does injection technique matter?

AIM AND BACKGROUND

Posttransplant vesicoureteral reflux (VUR) is a common urologic complication after renal transplantation, although its management is controversial. The treatment of choice is open surgical revision ureteral reimplantation with significant morbidity. Recently, endoscopic correction by using nonanimal dextranomer/hyaluronic acid copolymer (NA Dx/HA) injection has been reported to be effective in the treatment of VUR of transplanted kidneys. Herein, we present our 3-year endoscopic correction results in transplanted kidneys where we used two different injection techniques, subureteral and intraureteral.

MATERIALS AND METHODS

We retrospectively reviewed all patients who underwent endoscopic VUR correction of posttransplant VUR by NA Dx/HA injection between July 2005 and March 2009. We excluded patients with underlying urologic abnormalities.

RESULTS

A total of 26 patients (14 women and 12 men) with a mean age of 32.2 years (range: 15–55) were studied. The VUR was also graded as nondilating reflux in 10 (grade I–II) and dilating reflux in 16 (grade III–IV). Seventeen ureters (5 nondilating and 12 dilating VUR) were injected NA Dx/HA intraureterally, and 9 ureters (5 nondilating and 4 dilating VUR) were injected NA Dx/HA subureterally. Overall success rate was 53.8% (14 out of 26). Intraureteral injection technique was successful in nine cases (52.9%), and subureteral injection technique was successful in five cases (55.5%). In nondilating VUR, injection corrected 90% (9 out of 10) of posttransplant patients, whereas in dilating VUR group injection corrected only 31.25% (5 out of 16). We found no statistical significance of injection technique on the success rate.

CONCLUSIONS

Endoscopic correction by using NA Dx/HA with any injection technique seems to be a plausible alternative to correction of refluxing posttransplant ureters, particularly in nondilating VUR.

A novel surgical technique for management of vesicoureteral reflux following kidney transplantation: prospective study of 12 cases

The incidence of vesicoureteral reflux (VUR) varies between 10% and 80% of transplanted kidneys. In cases of failure of endoscopic treatment or recurrent urinary tract infections, surgical correction is proposed by ureteral reimplantation or pyeloureteral anastomosis using the native ureter. The aim of this study was to assess the results of a technique that increases the submucosal length of the ureter without a ureterovesical reimplantation. We treated 12 patients with VUR in the transplanted kidney by open surgery. Retrograde cystography showed resolution of reflux in all the patients. Our technique has the advantage of avoiding ureteral dissection thereby avoiding its devascularization and no invasion of the bladder mucosa.

Endoscopic application of dextranomer/hyaluronic acid copolymer in the treatment of vesico-ureteric reflux after renal transplantation

OBJECTIVE

• To evaluate the success of endoscopic dextranomer/hyaluronic acid copolymer (DHAC) application in the treatment of patients with recurrent urinary tract infections (UTIs) and vesico-ureteric reflux (VUR) into the transplanted graft after renal transplantation.

PATIENTS AND METHODS

• Between January 2008 and April 2009, 19 patients with recurrent UTIs presented VUR proven by voiding cystourethrography. • To correct VUR of the transplanted ureter, DHAC was injected endoscopically using hydrodistention technique. • Pre- and postoperative serum creatinine levels, the number of pre- and postoperative UTIs, postoperative complications and reflux resolution rate were recorded. The mean follow-up was 6.5 months.

RESULTS

• The average number of UTIs was reduced significantly from 4.89 (range 2-14) to 1.31 (range 0-4) on pre- and postoperative follow-up, respectively, of 6 months (P < 0.001). The success rate increased from 57.9% after the first injection to 78.9% after the second injection. • The remaining four patients with residual VUR received long-term low dose antibiotic prophylaxis. In total, two (10.5%) patients developed increasing creatinine levels postoperatively as a result of distal ureteral obstruction, and temporary urinary drainage was necessary in both patients.

CONCLUSIONS

• DHAC appears to be an efficient and minimal invasive method for treating VUR after renal transplantation with respect to short-term success. • Further investigation with a larger group of patients and longer follow-up is needed to evaluate the prolonged effect, as well as any potential side effects.