Correlation of vesicoureteral reflux with degree of hydronephrosis and the impact of antireflux surgery

Understanding and Managing Pediatric Urinary Tract Infections in Vesicoureteral Reflux: Insights Into Pathophysiology and Care

Vesicoureteral reflux (VUR) is a pediatric condition identified by the backward flow of urine from the bladder to one or both ureters and kidneys, predisposing patients to recurrent urinary tract infections (UTIs) and kidney scarring. Continuous antibiotic prophylaxis has long been a mainstay of management aimed at preventing recurrent UTIs and resulting renal damage. This review critically discusses the evidence supporting the utilization of antibiotic prophylaxis in VUR, with a focus on its efficacy, safety, long-term outcomes, and future directions in management. The literature reveals that continuous antibiotic use as a prophylactic measure minimizes the possibility of having recurrent UTIs in VUR children, especially in high-grade reflux children. However, the overall benefit of continuous antibiotic prophylaxis in protecting against kidney scarring remains controversial. Furthermore, concerns about antibiotic resistance, adverse drug reactions, and the psychosocial burden on families have led to a reevaluation of this option's role in managing VUR. Emerging evidence supports the role of non-antibiotic interventions and the potential of surgical management in select cases. Future research should focus on identifying criteria of patients who would benefit most from continuous antibiotic prophylaxis and on developing novel therapeutic approaches to minimize the need for prolonged antibiotic use.

Postoperative hydronephrosis following ureteral reimplantation: Clinical significance and importance of surgical technique and experience

BACKGROUND

Though common, postoperative hydronephrosis (POHN) following ureteroneocystostomy raises concern for an underlying obstruction. We aimed to determine the clinical significance of POHN following open (OUR) or robotic (RALUR) ureteral reimplantation.

METHODS

We retrospectively reviewed pediatric patients who underwent ureteral reimplantation for vesicoureteral reflux (VUR) from 2008 to 2019 by a single surgeon. Baseline characteristics, operative outcomes, and trends in POHN were assessed. POHN was defined as new onset hydronephrosis or exacerbation of pre existing hydronephrosis. Renal ultrasounds were performed 1, 4, and 12 months postoperatively. Voiding cystourethrograms were performed 4 months postoperatively. Surgical experience for RALUR cases was defined as number of ureters operated over time.

RESULTS

Altogether, 93 patients (127 ureters) underwent RALUR and 19 patients (26 ureters) underwent OUR. POHN was found in 27.6% and 30.8% of ureters after RALUR and OUR, respectively. Rate and time to POHN resolution for RALUR (91.4%, 112 days) and OUR (75%, 211 days) were statistically similar. Odds of POHN after RALUR were directly related with preoperative VUR grade (Range OR: 2.82[2.26-3.52]) and surgical experience (Range OR: 8.88[7.16-11.02]). Surgical experience was inversely related with odds of VUR recurrence (Range OR: 0.41[0.32-0.54]). Rates of VUR resolution were comparable for OUR and RALUR patients. No patient required additional intervention for POHN.

CONCLUSIONS

Incidence and resolution rate of POHN after OUR and RALUR were similar. Higher VUR grades were associated with increased odds of POHN after RALUR. Increasing RALUR experience improved VUR resolution rate but increased odds of POHN. Surgical success rates were similar for RALUR and OUR.

LEVEL OF EVIDENCE

II.

Incidence and resolution of de novo hydronephrosis after pediatric robot-assisted laparoscopic extravesical ureteral reimplantation for primary vesicoureteral reflux

INTRODUCTION

With the advent of robot-assisted laparoscopic ureteral reimplantation (RALUR) for primary vesicoureteral reflux (VUR), understanding and minimizing its complications continues to be critical. Incidence of de novo hydronephrosis after RALUR could be indicative of an outcome that needs further study or could be a benign transient finding.

OBJECTIVE

In the present study, we hypothesized that the incidence of de novo hydronephrosis after RALUR is low and resolves spontaneously.

METHODS

An IRB-approved prospective single-institutional registry was utilized to identify all patients undergoing RALUR via an extravesical approach from 2012 to 2020. Patients with primary VUR and minimal (Grade I SFU) or no hydronephrosis prior to surgery were included. Patients who had other associated pathology or underwent concomitant procedures were excluded. Preoperative characteristics including VUR and hydronephrosis grades as well as post-operative clinical details and hydronephrosis grades were aggregated and analyzed.

RESULTS

86/172 (50%) patients (133 ureters), with median reflux grade of 3 (IQR: G2, G3) met the inclusion criteria. Patients underwent RALUR at a median age of 5.7 years (IQR: 3.4, 8.7) with median 36.2 months (IQR: 19.6, 63.6) follow-up. Renal ultrasound at 4-6 weeks post-op showed de novo hydronephrosis in 18 (13.5%) ureters; the complete resolution was seen in 13 ureters (72%) at a median of 4.5 months from surgery. Among the 5 with non-resolved hydronephrosis (SFU G2:4, G3:1), 2 patients (3 ureters) underwent subsequent interventions.

DISCUSSION

The present study evaluating the natural history of de novo hydronephrosis after RALUR-EV performed for primary VUR, is to our knowledge the largest cohort of patients undergoing RALUR that this has been studied in. In our cohort, the incidence of de novo hydronephrosis after RALUR was 13.5%, similar to rates reported in two OUR cohorts, and significantly lower than reported incidence rates of 22-26% in several OUR cohorts, and 30% in a RALUR cohort. In the present cohort, hydronephrosis resolved spontaneously in more than 72% of cases. The median time from surgery until resolution of hydronephrosis was 4.5 (1.6, 10.5) months, which is shorter in comparison to the average time to resolution of 7.6 months, reported by Kim et al. in an earlier study.

CONCLUSIONS

De novo hydronephrosis after RALUR can be followed with serial renal ultrasounds. The majority of de novo hydronephrosis post-RALUR is transient and resolves spontaneously within a year of surgery with a very low re-intervention rate.

Guidelines for the medical management of pediatric vesicoureteral reflux

Urinary tract infection is a bacterial infection that commonly occurs in children. Vesicoureteral reflux is a major underlying precursor condition of urinary tract infection, and an important disorder in the field of pediatric urology. Vesicoureteral reflux is sometimes diagnosed postnatally in infants with fetal hydronephrosis diagnosed antenatally. Opinions vary regarding the diagnosis and treatment of vesicoureteral reflux, and diagnostic procedures remain debatable. In terms of medical interventions, options include either follow‐up observation in the hope of possible spontaneous resolution of vesicoureteral reflux with growth/development or provision of continuous antibiotic prophylaxis based on patient characteristics (age, presence/absence of febrile urinary tract infection, lower urinary tract dysfunction and constipation). Furthermore, there are various surgical procedures with different indications and rationales. These guidelines, formulated and issued by the Japanese Society of Pediatric Urology to assist medical management of pediatric vesicoureteral reflux, cover the following: epidemiology, clinical practice algorithm for vesicoureteral reflux, syndromes (dysuria with vesicoureteral reflux, and bladder and rectal dysfunction with vesicoureteral reflux), diagnosis, treatment (medical and surgical), secondary vesicoureteral reflux, long‐term prognosis and reflux nephropathy. They also provide the definition of bladder and bowel dysfunction, previously unavailable despite their close association with vesicoureteral reflux, and show the usefulness of diagnostic tests, continuous antibiotic prophylaxis and surgical intervention using site markings.

Does de novo hydronephrosis after pediatric robot-assisted laparoscopic ureteral re-implantation behave similarly to open re-implantation?

BACKGROUND

While open ureteral re-implantation surgery is the gold standard for surgical correction of vesicoureteral reflux (VUR), robot-assisted laparoscopic ureteral re-implantation via an extravesical approach (RALUR-EV) has become a minimally invasive alternative. Previous studies have shown that transient hydronephrosis after open re-implantation can occur in up to 28% of patients. However, previous studies have also shown that de novo hydronephrosis after open re-implantation is not predictive of final differential renal function.

OBJECTIVE

A retrospective review was performed to characterize the natural history of postoperative hydronephrosis after RALUR-EV for primary VUR in pediatric patients.

STUDY DESIGN

A retrospective chart review of a single-surgeon series was performed for pediatric patients who underwent RALUR-EV for primary VUR. The severity of de novo hydronephrosis was assessed using the Society for Fetal Urology (SFU) grading system via renal ultrasound at the 1-month postoperative follow-up. Renal ultrasound was performed at least every six months. Radiographic success was defined as complete resolution of VUR on the voiding cystourethrogram at the 4-month mark. Patient demographics, surgery duration, length of hospital stay, pre-operative and postoperative VUR grades, and follow-up time periods were collected. Patients with other associated urinary pathology and patients lost to follow-up were excluded from the study.

RESULTS

A total of 87 patients (121 kidney units) with primary VUR who underwent RALUR-EV met the inclusion criteria. SFU grade 1-3 hydronephrosis was noted in 30.3% (36/119) of kidney units at the 1-month mark, but 83.9% (26/31) cases with hydronephrosis completely resolved in a median time of 7.9 months (range: 3.4-21.0 months), and all four cases with unresolved hydronephrosis were downgraded to SFU grade 1 without the need for intervention.

DISCUSSION

A radiographic success rate of 96% was demonstrated in this cohort, which is comparable with that of historical open re-implantation series. A similar rate of de novo hydronephrosis was also noted in this cohort when compared with that of previous open re-implantation series, but de novo hydronephrosis after RALUR-EV had a similar or more rapid resolution rate than that previously reported after open intravesical and extravesical re-implantation series.

CONCLUSION

De novo hydronephrosis after RALUR-EV behaves similarly to de novo hydronephrosis after open ureteral re-implantation, where de novo hydronephrosis is present in up to 30% of pediatric patients who underwent RALUR-EV. The hydronephrosis self-resolves without the need for intervention in the overwhelming majority of cases and resolves at a median time of 7.9 months after surgery.

Does hydronephrosis predict the presence of severe vesicoureteral reflux?

We hypothesized that, in patients with vesicoureteral reflux (VUR) grade IV or V, hydronephrosis will likely be found, if the patient has a full bladder during the renal ultrasound examination. Eight hundred thirty-seven patients were included in the study. Patients ranged in age from <1 month to 18.7 years, with a median age of 1.3 years. Five hundred sixty-nine were female and 268 were male. In this retrospective study, each patient underwent a voiding cystourethrogram (VCUG) and a renal ultrasound examination. The presence of hydronephrosis and bladder filling status in 131 renal units with VUR grade IV or V was evaluated. Sensitivity and specificity for hydronephrosis to detect the presence of VUR grades IV and V were 60 and 92 %, respectively. Positive predictive value and negative predictive value were 74 and 87 %, respectively. Odds ratios for the relationship between hydronephrosis and severe VUR was significant (p = 0.046).

CONCLUSION

In patients with grade IV or V VUR, hydronephrosis will be observed in the presence of a full bladder. Therefore, a renal ultrasound could be considered a screening test to decide on performing a VCUG.

Hydronephrosis following ureteral reimplantation: when is it concerning?

OBJECTIVES

Hydronephrosis without obstruction is common prior to ureteral reimplant, especially in patients with high-grade VUR. Consequently, when hydronephrosis is present post-operatively, it is unclear when it should be concerning. We evaluated the finding of hydronephrosis in children undergoing reimplantation and its evolution following surgery.

METHODS

After obtaining IRB approval, we identified 938 children who underwent reimplantation at our institution from 1998 to 2006. Their pre- and post-operative US and clinical course were analyzed.

RESULTS

Hydronephrosis was observed in 24% pre-operatively and 21% post-operatively. 52% with pre-operative hydronephrosis had it post-operatively, while 12% without pre-operative hydronephrosis had it post-operatively. 71% of post-operative hydronephrosis resolved on average in 1.36 years. 19% didn't resolve and 0.1% had ureteral obstruction. Risk factors for post-operative hydronephrosis included increasing severity of VUR, and high degree of pre-operative hydronephrosis.

CONCLUSION

Hydronephrosis following ureteral reimplantation is not rare, and correlated to pre-operative evaluations. Post-operative hydronephrosis is frequently transient and benign, and usually resolves within the first 2 years. These patients do not require follow-up ultrasounds or further imaging, and can be followed clinically. Patients with high-grade VUR and hydronephrosis pre-operatively, however, are at risk for developing worsened hydronephrosis and should be followed with a 3-month post-operative ultrasound.

The clinical utility and safety of the endoscopic treatment of vesicoureteral reflux in patients with duplex ureters

OBJECTIVE

A systemic review of published literature on the use of bulking agents in the treatment of vesicoureteral reflux (VUR) in patients with duplex systems was performed in order to evaluate the diagnostic challenges; determine success rates, and compare with use in single systems; and evaluate safety, in particular of Deflux.

METHODS

A PubMed/Medline search was conducted for index articles discussing duplex ureters published in 1963-2007. All types of publications were included. A multiple linear regression analysis was performed.

RESULTS

Overall, 28 different treatment arms originating in 17 separate studies (19 publications) satisfied the inclusion criteria for linear regression efficacy analysis. Data were available on 2879 patients: 2400 with single and 479 with duplex systems. Ten publications provided information on the frequency of failure to diagnose duplex systems using specific techniques. An overall 18% failure rate to detect duplex systems was reported for combined techniques. For patients in whom favorable anatomic location of ureters allowed successful endoscopic injection of a bulking agent, correction of VUR was achieved in 53-100% of cases. A univariant analysis showed no difference in success rate between single and duplex systems with the use of Deflux, or other bulking agent. The predicted probability of success in a single system was 68% and in a duplex system 64%.

CONCLUSIONS

There is significant potential for failing to detect duplex systems prior to preparing an individual for either open or endoscopic treatment. From the studies available, endoscopic injection of bulking agents is highly successful in correcting mild-to-moderate VUR in duplex systems, with no reports of serious or clinically significant adverse effects. At a minimum, duplex systems would not seem to be a contraindication to the use of Deflux or any other bulking agent.

The role of the Lich-Gregoir procedure in refluxing duplicated collecting systems: experience from long-term follow up of 45 children

OBJECTIVE

The need for surgical correction of vesicoureteral reflux (VUR) is increased in duplicated systems. The aim of this study was to evaluate the outcome of the Lich-Gregoir procedure (LG) with regard to VUR persistence, contralateral de-novo VUR, hydronephrosis, preservation of split renal function, urinary tract infections (UTI) and postoperative side effects.

PATIENTS AND METHODS

Between 1993 and 2007, 45 children (mean age 3.2 years) underwent a unilateral common sheath LG. A combined number of at least 75 episodes of febrile UTI had occurred in 39 children prior to surgery. VUR grades I to V were present in two, nine, 16, 16 and two children, respectively. Hydronephrosis was present in 18 children. Mean split renal function was 44.03% (range 15-63%). Indications for surgery were febrile breakthrough UTI in 11 children and abscessing pyelonephritis in two. The remainder underwent surgery due to renal scars, reduced split renal function (<45%), VUR persistence and/or parental desire.

RESULTS

Persistent ipsilateral and de-novo contralateral VUR were detected in three children (ipsilateral in one, contralateral in one, bilateral in one), resulting in a 4.4% rate of persistent ipsilateral VUR. One year post surgery, low-grade hydronephrosis persisted in six patients without impact on split renal function. Mean split renal function remained stable at 44.06% (range 15-68%). During follow up (mean 41 months), six febrile UTIs occurred in five girls (92.4% risk reduction, P<0.00000005). Neither urinary retention nor any other side effect was observed.

CONCLUSION

Performed unilaterally, common sheath LG is a safe and effective technique to cure VUR, prevent febrile UTI and maintain split renal function in duplicated systems with otherwise uncomplicated anatomy.

The Role of Endoscopic Treatment in the Management of Grade V Primary Vesicoureteral Reflux

OBJECTIVES

Although endoscopic treatment provides a high rate of success in children with grades II-IV vesicoureteral reflux (VUR), its role in the management of grade V reflux has been questioned. In this study we reviewed our 21-yr experience of endoscopic treatment in children with grade V primary VUR.

METHODS

We retrospectively reviewed the medical records of 132 children who underwent endoscopic treatment for primary grade V reflux from 1984 to 2004. VUR was unilateral in 39 patients and bilateral in 34, and 59 patients had ipsilateral grade V reflux with a lower grade of VUR on the contralateral side. Endoscopic treatment was performed in a total of 166 grade V ureters; polytetrafluoroethylene was used from 1984 to 2000 and dextranomer/hyaluronic acid from 2001 to 2004. Median follow-up was 12.2 yr and mean follow-up was 13.4 yr.

RESULTS

VUR was completely resolved after first injection in 88 (53%) ureters and downgraded to grade I or II in 26 (15.7%). VUR resolved after a second and third injection in 36 (21.7%) and 10 (6%) of ureters, respectively. Endoscopic treatment failed to correct VUR in 6 (3.6%) ureters, requiring ureteral reimplantation in 5 and nephrectomy in 1. Thirteen patients developed urinary tract infections during the follow-up period, and on investigation 9 ureters (5.4%) had recurrence of VUR. No injection or morbidity related to tissue-augmenting substances was noted in any patient.

CONCLUSION

Endoscopic treatment should be the first-line of treatment in management of grade V vesicoureteral reflux.

[Evidence-based medicine and vesicoureteral reflux]

Vesicoureteral reflux (VUR) remains one of the most controversial subjects in paediatric urology. Much literature has been published on VUR, making the understanding of this anomaly and its treatments quite opaque. Evidence-Based Medicine (EBM) should be helpful to clarify the various VUR approaches contained in the 6224 titles found on Medline using the keywords "vesicoureteral reflux" and "vesicoureteric reflux". These articles were critically reviewed and graded according to EBM scorings, with regard to their methodological designs. This review of VUR literature suggests that most of our knowledge is based on publications with a low level of evidence, and that EBM lacks arguments to support recommendations for VUR diagnostic and treatment. It appears yet that antenatal dilatation of the urinary tract and symptomatic urinary tract infections (UTI) justify VUR screening. Surgery should be discussed in recurrent UTIs or deterioration of renal function. There is no consensus in case of persistent asymptomatic VUR regarding indication and duration of antibio-prophylaxis, and selection of radical treatment.