Refluxing Renal Units Research Articles

THE NATURAL HISTORY OF NEONATAL VESICOURETERAL REFLUX ASSOCIATED WITH ANTENATAL HYDRONEPHROSIS

Purpose: In an attempt to evaluate the natural history of neonatal vesicoureteral reflux, patients with antenatal history of hydronephrosis and documented reflux in the first 30 days of life were analyzed.Materials and Methods: Between 1993 and 1998, 260 patients with a history of antenatal hydronephrosis were referred for evaluation. Of these patients 31 were diagnosed with unilateral or bilateral refluxing renal units (54 renal units). Patients were treated with a prospective plan of observational therapy and prophylactic antibiotics, and resolution rate was calculated in patients with adequate followup. Reflux grade was correlated with postnatal ultrasonographic findings, urinary tract infections and differential renal function. Outcome analysis of 34 high grade (III to V) refluxing renal units using the Kaplan-Meier survival curves was undertaken with the end point being complete resolution or improvement. Three patients with vesicostomy and 2 who underwent ureteral reimplantation were excluded from a...

The natural history of neonatal vesicoureteral reflux associated with antenatal hydronephrosis.

In an attempt to evaluate the natural history of neonatal vesicoureteral reflux, patients with antenatal history of hydronephrosis and documented reflux in the first 30 days of life were analyzed. Between 1993 and 1998, 260 patients with a history of antenatal hydronephrosis were referred for evaluation. Of these patients 31 were diagnosed with unilateral or bilateral refluxing renal units (54 renal units). Patients were treated with a prospective plan of observational therapy and prophylactic antibiotics, and resolution rate was calculated in patients with adequate followup. Reflux grade was correlated with postnatal ultrasonographic findings, urinary tract infections and differential renal function. Outcome analysis of 34 high grade (III to V) refluxing renal units using the Kaplan-Meier survival curves was undertaken with the end point being complete resolution or improvement. Three patients with vesicostomy and 2 who underwent ureteral reimplantation were excluded from analysis. Reflux was grade I in 5% (33% males), II in 15% (62% males), III in 32% (71% males), IV in 18% (90% males) and V in 30% (100% males) of the patients. Postnatal ultrasound findings correlated poorly with the presence and degree of vesicoureteral reflux. Of 17 patients followed for at least 14 months (average followup 20) there was complete resolution in 60% with grade III, 50% with grade IV and 28% with grade V reflux. Using the Kaplan-Meier estimate there was a 50% chance of improvement (decrease in reflux grade by at least 2 grades) in high grade reflux by age 16 months. Urinary tract infections developed in 8 patients (26%) while on antibiotics. Of 46 renal units in 23 patients evaluated with a renal scan before urinary tract infection, 12 had less than 35% function. A normal postnatal ultrasound should not be a basis for excluding the use of cystography. Our Kaplan-Meier estimate shows that high grade reflux does improve and may resolve spontaneously. In addition, renal scarring may be seen with high and low grade reflux in the absence of urinary tract infection but high grade reflux is associated with a higher incidence of infection.

THE MODERN ENDOSCOPIC APPROACH TO URETEROCELE

During the last 20 years the surgical approach to ureterocele has evolved from major open surgery to minimally invasive endoscopic puncture. We believe that the endoscopic approach decreases the need for open surgical procedures. We identified specific factors that predict the need for repeat surgery. We reviewed the charts of 60 new patients with ureterocele treated with primary endoscopic incision between 1991 and 1995. Followup ranged from 4 to 62 months (mean 20). Mode of presentation, ureterocele location, associated vesicoureteral reflux and association of the ureterocele with a duplex system were evaluated. Ureterocele wall thickness was assessed subjectively via radiographic and cystoscopic methods, and categorized as thin, intermediate and thick. All 9 patients with a single system ureterocele had an intravesical ureterocele. No patient had associated reflux nor did any require a secondary open procedure. In 3 cases new onset ipsilateral reflux into the ureterocele spontaneously resolved. Of the 51 patients with a duplex system and associated ureterocele 19 (37%) required a secondary open procedure. The ureterocele was intravesical and ectopic in 22 (43%) and 29 (57%) cases, respectively. Reflux was associated with the ureterocele in 27 patients (53%), and 12 (44%) required a secondary open procedure. A total of 11 patients underwent ureteral reimplantation of 15 refluxing renal units and only 2 renal units required ureteral tapering. Reflux is no longer present in 14 of the 15 renal units (93%). Patients with a thick walled ureterocele required repeat puncture more frequently than those with a nonthick ureterocele. With the use of modern endoscopic techniques children with intravesical and single system ureteroceles require secondary open surgery less frequently than those with ectopic and duplex system ureteroceles. The mode of presentation does not predict the need for a repeat open procedure. Thick walled ureteroceles require repeat endoscopic puncture more frequently than thin and intermediate walled ureteroceles.

A MULTICENTER OUTCOMES ANALYSIS OF PATIENTS WITH NEONATAL REFLUX PRESENTING WITH PRENATAL HYDRONEPHROSIS

Purpose Approximately 10 to 30% of prenatal cases of hydronephrosis result in the postnatal diagnosis of vesicoureteral reflux. Using a new generic prenatal-postnatal data sheet developed by the Society for Fetal Urology the characteristics, natural history and outcome of prenatal hydronephrosis confirmed postnatally to be vesicoureteral reflux were documented at 3 centers. Materials and Methods We performed a retrospective multicenter review of Society for Fetal Urology data sheets completed for each patient in whom prenatal hydronephrosis was proved to be postnatal vesicoureteral reflux from 1993 to 1998. Results In 56 male and 15 female patients with prenatal hydronephrosis a total of 116 refluxing renal units were confirmed postnatally. Of the 116 renal units 112 were hydronephrotic prenatally. During gestation increased hydronephrosis was noted with voiding in 4 cases. Of the 112 hydronephrotic renal units only 26 ureters in 15 patients were seen prenatally. The obstetrician considered the diagnosis of vesicoureteral reflux in only 24% of the cases. Postnatally 116 refluxing renal units were identified. Initial postnatal ultrasound was normal in 25% of the cases. Bilateral reflux was present in 36 male and 9 female patients. In 10 of the 19 uncircumcised patients (53%) urinary tract infection developed despite antibiotic prophylaxis. In 15 of the 74 renal units with grades III to V reflux the condition resolved at an average patient age of 0.9 and 2.1 years in boys and girls, respectively. A total of 27 refluxing renal units were reimplanted. Conclusions The majority of prenatal reflux occurs in boys, and it is high grade and bilateral. The data sheets designed by the Society for Fetal Urology are useful data collection instruments. The presentation and natural history of vesicoureteral reflux are different in male and female individuals. In a significant number of renal units grade reflux resolves spontaneously. Early circumcision may decrease the incidence of breakthrough urinary tract infection in this subpopulation. In addition, the effective management of prenatally detected reflux depends on multispecialty communication.

A multicenter outcomes analysis of patients with neonatal reflux presenting with prenatal hydronephrosis.

Approximately 10 to 30% of prenatal cases of hydronephrosis result in the postnatal diagnosis of vesicoureteral reflux. Using a new generic prenatal-postnatal data sheet developed by the Society for Fetal Urology the characteristics, natural history and outcome of prenatal hydronephrosis confirmed postnatally to be vesicoureteral reflux were documented at 3 centers. We performed a retrospective multicenter review of Society for Fetal Urology data sheets completed for each patient in whom prenatal hydronephrosis was proved to be postnatal vesicoureteral reflux from 1993 to 1998. In 56 male and 15 female patients with prenatal hydronephrosis a total of 116 refluxing renal units were confirmed postnatally. Of the 116 renal units 112 were hydronephrotic prenatally. During gestation increased hydronephrosis was noted with voiding in 4 cases. Of the 112 hydronephrotic renal units only 26 ureters in 15 patients were seen prenatally. The obstetrician considered the diagnosis of vesicoureteral reflux in only 24% of the cases. Postnatally 116 refluxing renal units were identified. Initial postnatal ultrasound was normal in 25% of the cases. Bilateral reflux was present in 36 male and 9 female patients. In 10 of the 19 uncircumcised patients (53%) urinary tract infection developed despite antibiotic prophylaxis. In 15 of the 74 renal units with grades III to V reflux the condition resolved at an average patient age of 0.9 and 2.1 years in boys and girls, respectively. A total of 27 refluxing renal units were reimplanted. The majority of prenatal reflux occurs in boys, and it is high grade and bilateral. The data sheets designed by the Society for Fetal Urology are useful data collection instruments. The presentation and natural history of vesicoureteral reflux are different in male and female individuals. In a significant number of renal units high grade reflux resolves spontaneously. Early circumcision may decrease the incidence of breakthrough urinary tract infection in this subpopulation. In addition, the effective management of prenatally detected reflux depends on multispecialty communication.

URETERAL REIMPLANTATION IN INFANCY: EVALUATION OF LONG-TERM VOIDING FUNCTION

Purpose The advisability of early ureteral reimplantation in neonates and infants is controversial and to our knowledge long-term results are not available. We evaluated long-term voiding function after ureteral reimplantation in infancy. Materials and Methods Between 1984 and 1993, 32 children underwent ureteral reimplantation in year 1 of life at our institution. Long-term results were evaluated in regard to surgical outcome, voiding function, urinary tract infection and the need for prophylaxis. Analysis of voiding function included family interviews, uroflowmetry and post-void residual urine measurement. Results Complete long-term data were available in 14 girls and 7 boys. The diagnosis was primary bilateral and unilateral vesicoureteral reflux, and ureterovesical junction obstruction in 11, 4 and 6 cases, respectively. Of the 26 refluxing renal units overall disease was grade II in 3, III in 6 and IV to V in 17. Patient age at surgery was 0.6 to 12 months (mean 5.4) and followup was 5 to 13 years (mean 9.5). Tapered reimplantation was performed in 8 renal units using excisional or infolding in 5 and 3, respectively. There were no complications in 19 patients (94%), while 2 had postoperative reflux for which 1 underwent reoperation. In 13 patients voiding habits were normal, while 8 reported infrequent voiding (3 or fewer voids daily). In 19 of the 20 patients tested voided volume was appropriate, and the flow rate of 10.8 to 52.7 cc per second (mean 20.9) and post-void residual urine volume of 0 to 40 cc (mean 11) were considered normal. One patient with normal uroflowmetry had incomplete vesical emptying. Conclusions Early reimplantation may result in a high technical success rate and low postoperative morbidity in infants. After long-term followup infrequent voiding was common but noninvasive assessment of bladder function revealed no significant abnormality in the majority of patients.

Congenital reflux nephropathy: a follow-up of 108 cases diagnosed perinatally.

To determine: (i) the proportion of vesicoureteric reflux (VUR) associated with congenital renal damage and whether it can be severe enough to cause renal impairment from birth: (ii) to evaluate the distribution of males and females affected; and (iii) to describe the course of congenital damage in the first years of life. A total of 108 children (76 male and 32 female, M:F 2.3:1), whose VUR was diagnosed before any infection, were followed from birth for a mean (range) of 4.3 (1-10) years. Renal damage was defined by serum creatinine concentration, creatinine clearance and renal imaging (ultrasonography and renal scintigraphy) performed within the first month of life and periodically thereafter. Of the 108 children, 58 had bilateral and 50 unilateral reflux (total number of refluxing units, 166). High-grade VUR (grade > or = 4) was found in 96 (58%) refluxing renal units (RRUs). Males had a prevalence of bilateral severe (> or = grade 4) reflux (M:F 5.2:1), while in those wit unilateral VUR, the M:F ration was 1.5:1. At birth, mild to moderate damage was present in 56 (36%) RRUs and only associated with VUR of grade > or = 3. Bilateral reflux of grade > or = 4 was associated with congenital moderate/severe renal failure in nine neonates (seven males). In infants with grade > or = 4 VUR who underwent surgical correction, VUR resolved in 92% of cases. In infants with VUR of grade > or = 4 followed medically, the reflux spontaneously resolved in 42% and ameliorated in 16% after 18 months. Serial renal scans during the follow-up showed no progression of renal damage. VUR diagnosed at birth on prenatal ultrasonography is associated with congenital damage, with males affected more often than females. The damage involves both kidneys in a consistent proportion and is an important cause of chronic renal impairment from birth. It does not progress in the first years of life if infections are prevented. It is suggested that males with this condition may constitute a major group at risk of developing chronic renal failure in later life.

Can careful ultrasound examination of the urinary tract exclude vesicoureteric reflux in the neonate?

The aim of the study was to determine whether a urinary tract appearing normal when assessed by meticulous ultrasound (US) examination may coexist with vesicoureteric reflux (VUR) and whether a normal US scan can be used to exclude VUR, thereby avoiding unnecessary voiding cystourethrography (VCUG). The US features of 35 neonates with known VUR were reviewed. Criteria studied included pelvic dilatation above 7 mm on a transverse scan, calyceal or ureteral dilatation, pelvic or ureteral wall thickening, absence of the corticomedullary differentiation (CMD) and signs of renal dysplasia (small kidney, thinned or hyperechoic cortex and cortical cysts); all signs that have been shown to result from or to be associated with VUR. 57 refluxing renal units (RRU) were found among the 35 patients. VUR was bilateral in 22. Among the 57 RRU, at least one US anomaly that would have prompted VCUG was present in 50 (87.7%). Pelvic dilatation above 7 mm was present in 29 RRU (50.9%) only. Calyceal dilatation was present in 24 RRU, the dilatation involving the calyces but not the renal pelvis in seven. Ureteral dilatation was observed in 15 RRU. Pelvic or ureteral wall thickening was present in seven RRU. CMD was absent in 32 RRU (56.1%). US signs of dysplasia were found in 19 RRU. No US anomaly was found in seven RRU (12.3%) in six patients. A careful and meticulous US examination of the neonatal urinary tract allows the detection of over 87% of RRU by showing at least one sonographic abnormality. It is concluded that a normal appearing urinary tract on US does not usually coexist with VUR and that in such cases VCUG is not necessary.

Early Versus Late Surgical Management of Fetal Reflux Nephropathy

Considering that infants with reflux nephropathy may be susceptible to urinary tract infection or longer postnatal vesicoureteral reflux, an early antireflux procedure rather than chemoprophylaxis may be indicated after birth. In 15 male and 7 female neonates bilateral and unilateral primary high grade vesicoureteral reflux was detected prenatally in 15 and 7, respectively, on the basis of dilatation of the urinary tract. There was grade III or IV reflux in the 37 refluxing renal units and all patients received chemoprophylaxis after birth. In 11 neonates congenital reflux nephropathy was diagnosed during month 1 of life, including 5 (9 refluxing renal units) who underwent early antireflux surgery without evidence of urinary tract infection and 6 (11 refluxing renal units) who underwent late surgery with a history of urinary tract infection. All patients treated nonsurgically and surgically were monitored up to 2 years and for 2 years postoperatively, respectively. Of the 11 patients (17 renal units) without congenital reflux nephropathy reflux improved in 53%, a documented urinary tract infection occurred in 2 and there was no development of new scars in a previously normal kidney. In the 11 patients (20 renal units) with congenital reflux nephropathy the parenchymal defect detected during month 1 of life was general or focal, that is at the mid zone as well as the poles. Surgery was performed at a mean of 8 weeks of life in 5 patients without a documented urinary tract infection, 24 weeks earlier than in the 6 with a history of urinary tract infections. Postoperative breakthrough infections occurred in all 6 infants who underwent late surgery and in none who underwent early surgery (p < 0.05). New scarring developed in previously scarred renal units but there was more new scarring in the renal units treated with late surgery (10 of 11, 90%) than in those treated with early surgery (2 of 9, 22%, p < 0.001). In both groups retardation of growth was identified in the renal units with general nephropathy. Renal units with fetal reflux nephropathy were susceptible to urinary tract infections and new scar formation. Early antireflux surgery performed before a urinary tract infection develops offers a better prognosis than late surgery.

Common Sheath Reimplantation Yields Excellent Results in the Treatment of Vesicoureteral Reflux in Duplicated Collecting Systems

Purpose We evaluated our 10-year experience with the surgical treatment of vesicoureteral reflux in uncomplicated duplicated collecting systems. Materials and Methods Between 1984 and 1994, 54 refluxing renal units (8 bilateral) in 37 female and 9 male patients required surgery. Patient age ranged from 7 months to 17 years (average 4.9 at surgery). Postoperative followup (average 14.2 months) included voiding cystourethrography and renal sonography or excretory urography. Results Common sheath ureteral reimplantation via an intravesical approach was performed in 48 of the 54 refluxing renal units. Of the remaining 6 renal units detrussorrhaphy was performed in 4, and ureteroureterostomy combined with ureteral reimplantation and partial lower pole nephrectomy were done in 1 each. Two treated renal units had persistent postoperative vesicoureteral reflux, which resolved after subureteral polytetrafluoroethylene (Teflon) injection. No renal unit had postoperative hydronephrosis. Contralateral reflux was identified in 1 patient who underwent unilateral reimplantation. Our overall success rate was 96 percent for the surgical correction of vesicoureteral reflux in uncomplicated duplicated collecting systems. Common sheath reimplantation had a 98 percent success rate. Conclusions Although a duplicated collecting system increases the risk for surgical treatment, the presence of a duplication anomaly does not adversely affect surgical outcome. Modifications of procedures commonly performed in the surgical treatment of single system reflux to accommodate common sheath reimplantation have excellent surgical results with minimal morbidity.

Low anorectal anomalies: a critical appraisal

Retrospective review of 38 consecutive children with low anorectal anomalies encountered over a 7-year period was undertaken. Detailed follow-up data were available on 32 patients. Only 15 (47%) were diagnosed in the neonatal period, 6 being diagnosed after 6 months of age. Three patients had a colostomy performed prior to referral. Surgical correction was mainly by dilatation (7), cutback (8), or anoplasty (13). Associated anomalies occurred in 35% of patients; in addition, 19 (59%) had vesicoureteric reflux (VUR) with a total of 27 refluxing renal units. Three patients have undergone reimplantation of ureters. Intractable constipation was a major problem in 25% of patients and was unrelated to the time of diagnosis or treatment. The results showed that conventional management of low anorectal anomalies is followed by a substantial incidence of bowel problems. Due to the high incidence of associated VUR, all patients with anorectal anomalies should have a detailed urological assessment, including a micturating cystourethrogram.

Long-Term Follow-Up of Children with Surgically Treated Vesicorenal Reflux: Renal Growth

Renal growth after successful surgical correction of vesicoureterorenal reflux (VUR) in childhood was observed in 137 female and 22 male patients over a mean follow-up period of 10.5 years. The renal parenchymal area was determined using a compensatory planimeter. For each measured value, the standard deviation score (SDS) was calculated by comparison with a normal population. On average, renal growth after reflux operation nearly paralleled the expected normal growth rate. Scarred kidneys had a worse growth prognosis than refluxing renal units (RU) without renal damage, growth retardation being correlated with the degree of pyelonephritic changes. The diminished growth rate of scarred kidneys was accompanied by a compensatory growth of the contralateral kidney. In the absence of renal scars, a modest tendency toward growth retardation was seen in kidneys with previously high degrees of VUR. In 39.7% of the unscarred RU with an initial SDS less than -0.5, accelerated growth (change in SDS of 0.5 or more) was observed. Accelerated growth was most accentuated on small unscarred kidneys (initial SDS less than -2.0).

The fate of contralateral ureter after ipsilateral reimplantation in unilateral vesicoureteric reflux

Four patients out of 23 girls and 7 boys who were treated by successful ureteroneocystostomies for unilateral reflux had postoperative contralateral reflux (13.33%). Three of these 4 refluxing ureters resolved with medical treatment. A second surgery was needed in only 1 case (3.33%) who did not respond to medical treatment. There was no correlation between the preoperative severity of ipsilateral reflux, intravenous urography findings and the onset of contralateral reflux after unilateral reimplantations. Data from this study and previous works indicated that bilateral reimplantations are not warranted for unilateral refluxing renal units unless there are position and shape anomalies at the ureterovesical angle and a very careful preoperative evaluation of the patients is mandatory in this regard.

Fetal Vesicoureteric Reflux

We present an analysis of 30 patients with fetal vesicoureteric reflux (VUR) from a series of 107 patients with prenatally diagnosed urinary tract anomalies. In 13 patients (Group 1) the fetal VUR was the only urinary tract abnormality. In 17 patients (Group 2) the fetal VUR was combined with other urinary tract problems. In 14 of 46 refluxing renal units there was no evidence of upper tract dilatation on a pre- and post-natal ultrasound examination. Any infant with postnatal urinary tract dilatation needs full urological investigations, including a micturating cystogram. A normal postnatal ultrasound examination does not exclude fetal VUR.

Reflux nephropathy secondary to intrauterine vesicoureteric reflux

In 107 infants with 182 antenatally diagnosed urinary tract anomalies, 24 had either unilateral (12) or bilateral (12) vesicoureteric reflux (VUR). The VUR was more common in boys (male to female ratio, 16:8) and usually severe (grades IV [16], III [10], II [4], and I [6]). Intravenous pyelography showed the changes of atrophic pyelonephritis in 10 refluxing units, and in another two with an associated pelviureteric junctional hydronephrosis. Lateral ectopia of the ureteric orifices was noted in six of these 10 refluxing renal units. Isotopic renography showed a reduction in function in nine of the 14 patients examined, ranging between 9% and 41%. (45% and above was considered within the normal range). Only two patients developed a urinary infection before intravenous pyelography or isotopic renography was performed, suggesting that renal changes noted were primary rather than secondary. Findings support the hypothesis that foetal VUR may be a contributing factor in the causation of atrophic pyelonephritis (foetal reflux nephropathy) observed in these patients.

Correction of vesicoureteral reflux by the Gil-Vernet procedure.

Gil-Vernet antireflux procedure has been carried out for 22 refluxing renal units (14 patients), yielding a positive outcome in all, with disappearance of refluxing in 94% of the renal units with grade II, III and IV vesicoureteral reflux. The efficiency and simplicity of the technique is emphasized.

Extravesical Ureteroplasty

The results of extravesical ureteroplasty (Lich-Gregoir technique) for primary extravesical reflux in 62 children with 82 refluxing renal units are evaluated. Postoperative radiograms revealed persistent reflux in 5 (6.1 per cent) and obstruction in 1 (1.2 per cent) of the renal units. Of 7 patients in whom bilateral reflux had been noted previously but who had unilateral reflux at the time of operation, unilateral repair resulted in absence of reflux on the contralateral side in 6. The favorable success rate, low morbidity and median 5-day hospitalization support the use of extravesical ureteroplasty for uncomplicated reflux.