Impact of early vesico ureteral reflux on the transplanted kidney

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.

Vesicoureteral Reflux in Nonfunctioning Renal Allograft Incidentally Detected in a Posttransplant 99mTc-DTPA Scan: Significance of Postvoid Imaging

ABSTRACT

In the present note, a case with rising serum creatinine shortly posttransplantation was referred for 99mTc-DTPA scan. The previous nonfunctioning renal allograft in the left hemipelvis showed no finding during dynamic phase of scan and filling phase of bladder but revealed a high-grade vesicoureteral reflux (VUR) in postvoid image, which can be responsible, partly, for the patient's present and prior symptoms.

Vesicoureteral Reflux in Kidney Transplantation

BACKGROUND

Vesicoureteral reflux (VUR) is frequently found after transplantation, but its impact on graft function, urine tract infection, and graft loss remains uncertain. Therefore our objective was to evaluate the effects of VUR on the outcome of renal transplantation.

MATERIAL AND METHODS

We included 1008 adult renal transplant recipients of whom a 1-week posttransplant voiding cystourethrogram was available. Study end points included occurrence of bacteriuria, renal function, and graft survival.

RESULTS

In total, 106 (10.5%) of 1008 graft recipients had a diagnosis of VUR on voiding cystography. The incidence of bacteriuria was comparable in the reflux and nonreflux group (17% vs 17.4%, P = .91). There was no significant difference in renal function at 3 months and 1 year in patients with and without VUR. One- and 5-year graft survival in patients with VUR was 85.8% and 82.1% compared to 87.3% and 83.0% in patients without VUR ( P = .68 and P = .80).

CONCLUSION

Posttransplant VUR has no correlations with early bacteriuria, renal function, and graft survival.

The modified Barry technique to prevent vesicoureteric reflux in paediatric renal transplant recipients: initial recipient outcomes

OBJECTIVE

We present the initial clinical results of the 'modified Barry technique' for the prevention of VUR in paediatric renal transplant grafts. Ours is the only centre in the UK using this technique, as confirmed in a questionnaire developed in our department.

PATIENTS AND METHODS

We retrospectively analysed data of 15 paediatric renal transplant patients (operated June 2006-November 2009) who had their vesicoureteric anastomosis performed using the modified Barry technique with a 2-cm submucosal anti-reflux tunnel. The original Barry technique involved the creation of a 4-cm tunnel; this was modified by us to reduce the risk of ureteric stenosis.

RESULTS

At a median follow up of 23.7 months (6.3-39.4), the incidence of VUR was 7% (1/15). There was no evidence of postoperative urological complications, such as urinary leak, primary ureteric obstruction including anastomotic stricture/stenosis, transplant graft renal calculi and chronic rejection. At current follow up, graft and patient survival are 100%.

CONCLUSION

With the introduction of the modified Barry technique, the incidence of VUR in our series fell 10-fold to 7%, compared with our earlier study (P<0.0001), without any urological complications. Although the initial results are encouraging, larger patient numbers and longer follow up are required to validate this technique further.

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.

Comparing two ureter reimplantation techniques in kidney transplant recipients

We compared the incidence of urological and anastomotic complications for the ureteroureterostomy and Lich-Gregoir techniques in kidney transplant recipients. Between May 2003 and February 2004, 75 kidney transplant recipients from living donors were divided into two similar groups to receive ureteroureterostomy (n = 41, 28 male, 13 female) and Lich-Gregoir techniques (n = 34, 24 male, 10 female) for ureteral reimplantation. Patients with vesicoureteral reflux (VUR) to the native kidneys were excluded from the study. The urological complications included complicated hematuria, ureteral stenosis, symptomatic VUR, recurrent urinary tract infection (UTI). There was no statistical significance between two groups in terms of gender, age, end-stage renal disease etiology, human leucocyte antigen (HLA) mismatch numbers, type and duration of dialysis, and cold ischemia time. The incidence of urologic and anastomotic complications was 12%. Complications in the Lich-Gregoir group included symptomatic VUR in 8.8% and stent migration in 2.9% of cases. Complications observed in the ureteroureterostomy group were ureteral stricture 7.3% and complicated hematuria in 4.9% of cases. However, symptomatic reflux was not observed in the ureteroureterostomy group. UTI frequency was similar in both groups. Ureteroureterostomy can be safely performed as a primary choice in kidney transplant recipients.

Reflux Nephropathy in Kidney Transplants, Demonstrated by Dimercaptosuccinic Acid Scanning

BACKGROUND

This study determines why kidney transplants develop new focal defects.

METHODS

Thirty children at a U.K. pediatric nephrology department receiving kidney transplants had early and late dimercaptosuccinic acid (DMSA) scans to detect acquired focal defects, and their presence correlated with possible risk factors. Associations between clinical events and focal DMSA lesions appearing in grafts were measured.

RESULTS

Of the 30 early DMSA scans (within 2 weeks of function), one child with a thrombosed polar artery had a focal defect. On rescanning later, 11 (37%) had acquired segmental defects; five were multiple, and their glomerular filtration rates were 20 ml/min/1.73 m lower (95% CI 7-34). Histology in one case showed pyelonephritic scarring. Reflux into the transplant ureter occurred in 19/27 (70%) of children tested (by radiological or indirect radionuclide cystography). Nine of 13 children (69%) who had a combination of reflux and a urine infection had acquired scars, whereas only 1/14 (7%) did without this combination (P = 0.001). Scarring was not associated with the age or sex of the donor or recipient, rejection episodes, renal biopsy, or drug-induced nephrotoxicity.

CONCLUSION

Kidney transplants are at high risk of developing segmental pyelonephritic scars if infected urine refluxes into the graft, either early through a transanastomotic stent or later from vesicoureteric reflux. These scars may reduce the renal function and are readily seen on DMSA, but not ultrasound scans. Consideration should be given to more effective antireflux surgery for transplants, with subsequent testing for reflux, urinary antibiotic prophylaxis, and prompt treatment of urine infections.

Urological and Surgical Complications in 362 Consecutive Living Related Donor Kidney Transplantations

OBJECTIVE

The aim of this study is to review retrospectively the surgical and urological complications encountered in 362 cases of living related donor kidney transplantations (LRDTs).

MATERIAL AND METHODS

Between 1983 and 2002, 362 consecutive LRDTs were performed at our institution. The urological and surgical complications were determined in these cases.

RESULTS

Overall, urological and surgical complications were encountered in 57 (15.7%) of the renal transplants. Of the 362 patients, urological complications were detected in 29 of them (8.01%), including 5 urinary fistula (with 1 distal ureteral necrosis), 2 ureteric stenosis, 1 renal calculi, 8 symptomatic vesicoureteral reflux and 13 lymphocele requiring intervention. Vascular complications were developed in 5 patients such as renal vein thrombus in 1 and renal arterial stenosis in 4 cases. Wound infection was detected in 6 patients. Fourteen patients underwent surgical explorations due to perinephric hematoma during the early postoperative period. Renal allograft rupture due to accelerated rejection was developed in 2 cases. A lower segmental arterial injury occurred in 1 patient during the operation.

CONCLUSION

LRDT is an important treatment alternative for patients with end-stage renal disease. Many complications may occur after renal transplantations. Our rate of complications is within the range of the current literature. After a modification of our surgical technique, as not dissecting the external iliac artery, the number of lymphoceles has decreased dramatically and with using ureteric stents, we detected a significant decrease in urinary complication rates.

Endoscopy Treatment with Coaptite® in Symptomatic Vesico-Ureteral Reflux after Kidney Transplant: Initial Experience in Four Cases

The evidence of symptomatic vesico-ureteral reflux after kidney transplant impose its correction. In our experience the incidence of this correction is 1%. The first choice is endoscopes treatment with periorifitial injections (75% good results) with Teflon or Macroplastique. In the latest four patients with symptomatic vesico-ureteral reflux III degree (recurrent urinary infections, serum creatinina >20–40%) we applied Coaptite®, with three periorifitial injections. Coaptite® is a biocompatible material, natural and inert, made of calcium idrossiapatite spheres of 100 micron suspended in a water and glycerine gel. These characteristics made Coaptite® much more suitable in transplanted patients with immunosuppressive therapy. Coaptite® is X-ray opaque: treatments and results are more easily measurable. The results with Coaptite® are superimposable to Teflon or Macroplastique. We observed any complications.

Use of collagen injections for vesicoureteral reflux in transplanted kidneys

Reports in the literature suggest the incidence of vesicoureteral reflux (VUR) in transplanted kidneys to range from 2-79%. Collagen injections have been used with reported success rates of up to 65% to prevent VUR into native orifices in children, but have not been studied in transplant neo-orifices. We evaluated the use of collagen injections in seven patients with transplant kidney neo-orifices who displayed grades II-IV VUR and seemed to be related to symptomatic urinary tract infections (UTIs). Postoperative VCUGs obtained at 2 months showed improvement in the grade of reflux in four of seven (57.1%) patients; one (14.3%), no change; and two (28.6%), worse reflux. All patients also redeveloped symptomatic UTIs after collagen injection. We conclude that the use of collagen injections in kidney transplant neo-orifices did not prevent VUR. Although prevention of VUR may have been achieved short term, VCUG examinations 2 months after initial injection revealed persistent reflux. Etiologies for failure to prevent VUR may be the readily absorbable nature of collagen, technical aspects of the procedure, the degree of reflux, and anatomic differences between native orifices (which lie on a well-supported trigone) and transplant neo-orifices (which lie on the posterior wall with less support).

Cyclic voiding urosonography for detecting vesicoureteric reflux in renal transplant recipients

BACKGROUND

The clinical significance of vesicoureteric reflux (VUR) in renal transplant recipients remains controversial. Voiding urosonography (VUS), a new modality for detecting VUR, can be used in these patients. The sensitivity of X-ray and radionuclide cystography for detecting VUR may be improved with cyclic procedures. The aim of our study was to evaluate whether cyclic VUS is superior to the single-cycle procedure.

METHODS

Cyclic VUS was performed in 27 renal transplant recipients. Eight were children or adolescents and the remaining 19 recipients were adults. VUS was performed according to accepted guidelines. After the first micturition, the catheter was left in place and the entire procedure was repeated under the same conditions.

RESULTS

Both initial cycle and cyclic VUS detected 17 out of 27 (63%) VURs in the same patients. The sensitivity was not improved by cyclic VUS. However, there were differences between the initial cycle and cyclic VUS (P=0.028) when comparing the number of negative results and the grades of VURs detected. This difference was even more pronounced when analysing only positive results. In the initial cycle, five out of 17 (29%) VURs were grade III, compared with 10 out of 17 (59%) grade III VURs in the same patients using the cyclic procedure (P=0.008).

CONCLUSIONS

Cyclic VUS did not improve the detection sensitivity for VUR in our study. However, given that VUR grade may be important for the management of renal transplant recipients, the use of cyclic VUS may provide a useful diagnostic tool for these patients.