Use of collagen injections for vesicoureteral reflux in transplanted kidneys

Ureteral reimplantation after deflux failure for vesicoureteral reflux in renal transplant

PURPOSE

To evaluate the outcomes of ureteral reimplantation (UR) after failure of endoscopic treatment for symptomatic vesicoureteral reflux (VUR) in renal transplant recipients.

METHODS

We conducted a monocentric retrospective study that included all renal transplant recipients with failure of Deflux™ as first-line treatment of VUR from January 2007 to December 2020. Failure of Deflux™ was defined by: VUR on retrograde cystography and at least one acute pyelonephritis of the renal graft. The preferred surgical treatment was native ureteropyelostomy (NPUS) in the recent years. If the native ureter could not be used, ureteroneocystostomy (UNC) was performed. The primary outcome was the clinical efficacy of UR defined as the absence of acute graft pyelonephritis during follow-up.

RESULTS

Out of 1565 kidney transplantations, 119 (7.6%) had symptomatic VUR treated with bulking agent. 35 (29.4%) had Deflux™ failure and were addressed to UR: 21/35 (60%) NPUS and 14/35 (40%) UNC. The median estimated blood loss, operative time, and length of stay were 120 mL, 90 min, and 7 days, respectively. After a median follow-up of 7.1 (IQR 4.1-9.8) years, UR was clinically successful in a total of 32 patients (91.4%): 20 (95.2%) and 12 (85.7%) patients in the NPUS and UNC groups, respectively (p = 0.55). Three (8.5%) high-grade complications have been reported. No nephrectomy of native kidney was required in the NPUS group.

CONCLUSIONS

After failure of Deflux™ for VUR of renal graft, surgical treatment with native ureteropyelostomy or ureteroneocystostomy is associated to a high success rate and few high-grade complications.

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.

Renal function outcomes in pediatric patients with symptomatic reflux into the transplanted kidney treated with redo ureteroneocystostomy

INTRODUCTION

Asymptomatic post-renal transplant reflux is common but only 5-10% patients are diagnosed with vesico-ureteral reflux in the setting of post-transplant febrile urinary tract infections, requiring redo ureteroneocystostomy (redo-UNC). Here we report the renal function outcomes of 37 such patients, stratified by lower urinary tract (LUT) status.

OBJECTIVE

We hypothesized that those with pre-transplant LUT dysfunction would have lower glomerular filtration rate (GFR) on follow-up.

STUDY DESIGN

Using procedure codes, 37 patients who underwent renal transplant followed by redo-UNC for transplant reflux at our institution between 1991 and 2014 were identified. Patient characteristics and GFR levels from four different time points were recorded. Comparisons were made between those with and without LUT dysfunction, using Fisher's exact, Wilcoxon rank sum, or signed-rank tests. Generalized estimating equations were constructed to account for the clustered nature of GFR within each LUT group and to assess their change over time.

RESULTS

Twelve patients (32%) had pre-transplant LUT dysfunction. The proportion of males in this group was significantly higher (75% vs. 32%, p = 0.032), and there was no statistical difference towards presenting earlier with post-transplant reflux (1.4 vs. 2.3 years, p = 0.087). After an average of 4.9 years, the median GFRs were similar between the two groups (53 mg/dL vs. 58 mg/dL, p = 0.936). There was no significant difference in GFR at this last follow-up time point in patients with and without LUT dysfunction.

DISCUSSION

Vesicoureteral reflux in the setting of renal transplantation is common and doesn't often require repair. In our series, we found that those with LUT dysfunction did not present statistically sooner with symptomatic transplant reflux. Longer-term follow-up did show a decline in GFR but did not reveal a difference in GFR in patients' with and without LUT dysfunction.

CONCLUSIONS

Pediatric post-transplant GFR after open redo ureteral reimplant decreases over time in similar fashion in patients with symptomatic reflux regardless of whether they have LUT dysfunction or normal anatomy. Vigilance should apply to the recognition, treatment, and follow-up of all symptomatic transplant reflux regardless of LUT status.

Urological complications following unstented pediatric renal transplantation

Urological complications which develop post-renal transplantation can be associated with significant morbidity especially in children. We evaluated the occurrence and management of all urological complications in a series of unstented pediatric renal transplants in a tertiary pediatric hospital. We reviewed the medical records of children who underwent unstented renal transplant between January 1996 and December 2014. Postoperative urological complications and the outcomes of their management were analyzed. A total of 160 unstented renal transplants were performed, and 32 urological complications were noted in 29 transplants (18%). There were 20 boys and nine girls with an age range of 2.5 years to 18.4 years. Nine (31%) of these patients had LUTD. The most common complication was VUR occurring in 17 patients (10.6%). Urine leaks occurred in six patients (3.8%) and ureteric obstruction in six patients (3.8%), and three patients (1.9%) had unexplained hydronephrosis. Loss of graft occurred in three patients (1.9%), and one patient died from sepsis post-uretero-ureterostomy. Patients with LUTD had more urological complications (P = .037). Unstenting is feasible in most pediatric renal transplants. LUTD is associated with a higher incidence of urological complications, especially VUR.

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.

Management of urologic complications in renal transplantation: a single-center experience

INTRODUCTION

Ureterovesical complications subsequent to renal transplantation are associated with a high morbidity leading to graft loss or even death. In the present study, the management of these complications by using interventional and surgical procedures (native pyeloureterostomy [NPUS]/ureteroureterostomy [NUU] vs ureteroneocystostomy [UNC]) was evaluated retrospectively.

PATIENTS AND METHODS

Between 1994 and 2012, a total of 780 kidney transplantations (690 deceased and 90 living donors) were performed at our institution. Demographic, clinical, and laboratory data from patients with urologic complications were analyzed and compared.

RESULTS

Fifty patients (6.4%) exhibited ureterovesical complications, and 18 patients (36%) were operated on immediately. In 32 (64%) of 50 patients, an interventional procedure was initially performed, with 21 patients (66%) undergoing operation due to therapy failure. NPUS/NUU and UNC were performed in 26 (66.6%) and 13 (33.3%) patients, respectively. Indications for an operation were ureteral stenosis in 12 patients (30.8%), ureteral necrosis and urine leakage in 19 patients (48.7%), and symptomatic vesicoureteral reflux in 8 patients (20.5%). Long-term results were comparable between all groups.

CONCLUSIONS

Surgical revision of ureteral complications should be the standard therapy. NPUS/NUU, UNC, and the successful interventional procedures did not differ significantly in terms of long-term results.

Ureteropyelostomy using the native ureter for the management of ureteric obstruction or symptomatic reflux following renal transplantation

OBJECTIVE

To evaluate the outcome of ureteropyelostomy using the native ureter for the management of ureteric obstruction or symptomatic reflux after renal transplantation.

MATERIALS AND METHODS

This is a single-center retrospective review of consecutive patients who underwent ureteropyelostomy after renal transplantation between the years 2000 and 2009. Ureteropyelostomy was performed using the ipsilateral native ureter. The native kidney was not removed. Patients' baseline characteristics, preceding interventions, and postprocedural outcomes were analyzed.

RESULTS

Ten patients underwent ureteropyelostomy after renal transplantation. All had initial Lich Gregoir ureterovesical anastomosis. Reasons for the reconstructive surgery were transplant ureteric stenosis in 8 patients or vesicoureteric reflux causing recurrent graft pyelonephritis in 2 patients. Median follow-up was 53 months (range 24-76). Postoperative complications included 3 patients who had transient anastomotic obstruction after removal of the double pigtail stent. They were managed with short-term ureteric restenting or nephrostomy tube insertion. In addition, 2 patients required delayed ipsilateral native nephrectomy because of infection. At last follow-up, all grafts remained unobstructed and free of infections.

CONCLUSION

Ureteropyelostomy using the native ureter for the management of transplant ureteric obstruction or symptomatic reflux is safe and provides good long-term preservation of graft function in selected patients.

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.

Endoscopic treatment of symptomatic refluxing renal transplant ureteroneocystostomies in children

To present a multi-center experience with the use of Dx/HA copolymer for treatment of symptomatic refluxing renal transplant UNC in children. A multi-center, retrospective chart review was performed. Eleven patients with a mean age of eight yr underwent renal transplantation with an anti-refluxing UNC. Data were collected to determine the safety and effectiveness of the procedure and to identify possible predictors of success. Endoscopic treatment was successful in one of five males and five of six females, for an overall success rate of 54.5%. The etiology of renal failure was associated with success of treatment, with 4/6 (67%) patients with upper tract pathology demonstrating resolution of the VUR, as compared with one of three (33%) patients with lower tract pathology. Male patients had a higher incidence of lower tract pathology. No complications were associated with the endoscopic procedure. Endoscopic injection of Dx/HA remains a safe option for the treatment of symptomatic refluxing transplant UNC in children. Although the success rate is lower than that seen in the treatment of primary VUR, the minimally invasive nature and safety of this technique may offer advantages over open reconstruction of the refluxing transplant ureter.

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

BACKGROUND AND PURPOSE

Secondary vesicoureteral reflux (SVUR) after renal transplantation may cause recurrent urinary-tract infections (UTI) and loss of renal function. There are only a few reports on the endoscopic treatment of SVUR by transurethral injection therapy. This is the first report of transurethral injection of dextranomer/hyaluronic acid copolymer (Deflux; Q-Med Scandinavia, Uppsala, Sweden) to relieve SVUR after renal transplantation.

PATIENTS AND METHODS

Between November 2003 and October 2005, four women were treated for SVUR with transurethral injections of dextranomer/hyaluronic acid copolymer. All patients had deterioration of renal function attributable to SVUR, recurrent UTI, or both. The mean follow-up was 29 months (range 16-38 months).

RESULTS

Initially, SVUR was corrected in all patients. Recurrent SVUR made a second treatment necessary in two patients. Three patients had no signs of SVUR 15, 27, and 36 months after the treatment. Renal function remained stable in these patients, and two were free of UTI. One of the patients who received two Deflux injections developed a filiform stenosis of the distal ureter, which was corrected by ureteropyeloplasty with the native ureter.

CONCLUSION

Transurethral injection therapy with Deflux is a minimally invasive treatment option for patients with SVUR after renal transplantation. A second treatment seems to be necessary in some cases. Complications such as ureteral obstruction may occur.

Vesicoureteral reflux after kidney transplantation in children

We analyzed the frequency of vesicoureteral reflux and the factors that favor its appearance after kidney transplantation in pediatric patients. This retrospective analysis examined the prevalence of post-transplant vesicoureteral reflux in a total of 181 kidney transplants performed in children at our center between 1978 and 2004. In patients who required corrective surgery for this problem, we analyzed pretransplant residual diuresis, pretransplant pathology and post-transplant problems related to vesicoureteral reflux. We also analyzed form of presentation, whether reflux was to the graft or to the native kidney, degree of reflux, and surgical technique used to correct reflux. Ten patients (5.5%) needed surgery to correct reflux to the graft (nine children) or to the native kidney (one child). Reflux was manifested as urinary tract infection in six children and progressive graft failure in one. Urethrovesical disorders that favored vesicoureteral reflux were present in eight patients (non-compliance bladder, detrusor overactivity, posterior urethral valves, urethral stenosis). Lengthening the submucosal tunnel stopped urinary tract infections in all 10 patients, whereas six-month voiding cystourethrograms showed resolution in 8 patients and (only) reduction in the degree of reflux in two. The high percentage of post-transplant vesicoureteral reflux in pediatric patients were related with higher frequencies of ureterovesical pathology in children who received the transplant. Lengthening the submucosal ureteral tunnel vesicoureteral reflux was corrected in 80%. We recommend during implantation in children with pretransplant urethrovesical abnormality an initial technique, which utilizes a longer submucosal tunnel such as the Lich-Gregoir.

Early and late urological complications corrected surgically following renal transplantation

The purpose of this study was to assess outcomes of urological complications after kidney transplantation operation. Nine-hundred and sixty-five patients received a kidney transplant between 2000 and 2006. In total, 58 (6.01%) developed urological complications, including urinary leakage (n = 15, 1.55%), stenosis (n = 29, 3%), vesicoureteral reflux (VUR) (n = 12, 1.2%), calculi (n = 1, 0.1%) and parenchymal fistulae (n = 1, 0.1%). Urinary leakage cases were treated by ureteroneocystostomy (UNS) via a double-J stent and stenosis cases by UNS. Fenestration was performed in patients developing lymphoceles and unresponsive to percutaneous drainage. VUR treatment was performed by ureteroneocystostomy revision or UNS. Stent usage during ureteric reimplantation was observed to reduce urinary leakage. Surgical complication rates in renal transplantation recipients according to donor type (living versus cadaveric) and the status of stent use (with stent versus without stent) were 5.53% vs. 7.27% (P = 0.064) and 5.24% vs. 20% (P < 0.01) respectively. No recurrence, graft loss or death was seen after these interventions. Comparison of recipients with and without urological complication showed that there was no difference between groups (P > 0.05) with respect to last creatinine level. No graft or patient loss was associated with urological complications. Urological complications that can be surgically corrected should be aggressively treated by experienced surgeons and graft loss avoided.

Urologic complications in kidney transplantation

Urologic complications in kidney transplantation have an incidence ranging from 3% to 20%, representing an important cause of organ loss. From January 2001 to September 2004, 123 renal transplantations were performed using an immunosuppressive protocol including basiliximab, mycophenolate mofetil, calcineurin inhibitors, and steroids. The surgical technique was vascular anastomoses to external iliac vessels, and ureteral anastomosis according to Lich Gregoire technique using a JJ ureteral stent. We report 5 renal complications (4.2%) and 4 extrarenal complications (3.5%), the majority of which required corrective surgery. The surgical strategy uses the clinical condition of the donor and the recipient; the anatomic anomalies of the graft, and a reduced cold ischemia time. Moreover, a reduction in acute rejection episodes and immediate renal function has been fundamental to reduce urologic complications. In fact, the main cause of urologic complications is ureteral ischemia, linked both to backtable surgery and to rejection episodes. Another important factor in the reduction of early urologic complications has been the routine use of a JJ stent, which allowed us a conservative approach in this setting.