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Biomedical subjects

S P Greenfield

Publications and source records attributed to S P Greenfield.

At least 19 recordsLinked to original sources
PubMed2001

Management of vesicoureteral reflux in children.

Although much has been learned about the diagnosis and management of vesicoureteral reflux, several important areas of investigation remain. Because not all children with reflux are equally susceptible to renal scarring and the development of reflux nephropathy, controversy surrounds the need to evaluate all children with urinary tract infection or to continue prophylaxis in known refluxing children after a certain age. In addition to age, other factors such as sex, grade of reflux, and the presence of voiding dysfunction can all play a role. The grade of reflux as seen on the contrast voiding cystourethrogram is the best predictor of reflux resolution in large numbers of patients, but grade alone cannot predict spontaneous cessation in any one individual. Attempts at refining more quantitative imaging modalities have so far proved unsuccessful. Open ureteral reimplantation remains the standard for surgical care if surgery is necessary. Both cystoscopic and laparoscopic techniques, however, may ultimately prove to be reliable, minimally invasive approaches to definitive correction. Finally, there are data to support continued diagnosis and treatment of reflux in at-risk populations. The incidence of reflux-related morbidity in children has significantly diminished over the last three decades. A major challenge is to better identify at-risk subpopulations of children with reflux, so that not every child will require intensive, long-term medical treatment or surgery.

Age Factors↗
PubMed2000

The relationship between dysfunctional voiding and congenital vesicoureteral reflux.

Voiding dysfunction may play an etiological role in congenital vesicoureteral reflux in otherwise normal children. There is increasing evidence to suggest that in some infants and older children, vesicoureteral reflux is associated with congenital structural deficiency of the trigonal ureterovesical junction valve mechanism as well as aberrant lower urinary tract function. In the youngest infants this abnormal function can be present at birth, whereas in older children it may be acquired and learned during the toilet training years, if it is not already present. Voiding dysfunction may spontaneously improve or require additional therapy. Increased rates of breakthrough infection, renal scarring and surgical failure have been associated with undiagnosed and untreated lower urinary tract dysfunction, emphasizing the importance of its recognition. Controversy remains regarding the role of invasive urodynamics and anticholinergic medication, and further large-scale prospective studies are necessary before either modality becomes routine when assessing and treating these children.

Age Factors↗
PubMed1999

Contemporary incidence of morbidity related to vesicoureteral reflux.

OBJECTIVES: The association among vesicoureteral reflux (VUR), renal scarring, and reflux nephropathy is well established. Screening programs for children who present with urinary tract infection (UTI) and their siblings, along with medical and surgical management, have been promoted by pediatric medical and urologic specialists in Buffalo and the surrounding community for more than two decades. Has this comprehensive and costly effort resulted in a decrease in VUR-related morbidity and should it be continued? METHODS: The records of all active patients who presented from 1982 through 1997 to this region's single pediatric nephrology referral center were reviewed. One hundred twenty-two children and adolescents (73 boys, 49 girls) were identified with hypertension (HTN), renal insufficiency (RI), and end-stage renal disease (ESRD) requiring dialysis or transplantation. RESULTS: There were 70 patients (57%) with HTN, 19 (16%) with RI, and 33 (27%) with ESRD. Reflux nephropathy was the underlying cause in 6 patients (5%)-3 with HTN and 3 with ESRD. The etiologies of morbidity in the remaining patients were medical renal disease, 61 (50%); idiopathic, 17 (14%); obstructive uropathy, 14 (11%); primary congenital renal hypoplasia, 12 (10%); and vascular, 12 (10%). Of the 6 patients with VUR-related morbidity, 4 were boys (3 with ESRD, 1 with HTN) and 2 were girls (with HTN). Five children presented in the 1980s and 1 in the 1990s. Only 1 patient had a history of UTI, and she presented early in the series in 1982 at 5 years of age. Ages of presentation were infancy (2 boys), early childhood (1 boy, 1 girl), and adolescence (1 boy, 1 girl). Reasons for presentation were failure to thrive (n = 2), voiding dysfunction without UTI (n = 1), muscle cramps (n = 1), UTI (n = 1), and HTN (n = 1). Reflux grade ranged from I to V, but 4 patients had grade III or less. CONCLUSIONS: Awareness of VUR-related morbidity has led to more widespread diagnosis and treatment, which appears to have resulted in a dramatic decrease in the numbers of affected patients in this community. The diagnosis and treatment of VUR has altered the epidemiology of HTN and renal failure in children and young adults.

Adolescent↗
PubMed1998

Renal growth characteristics in children born with multicystic dysplastic kidneys.

OBJECTIVES: To report on the growth characteristics of the affected and contralateral kidneys in children born with multicystic dysplastic kidneys (MCDKs). METHODS: Thirty-three patients were enrolled from 1970 to 1995: 23 were initially managed nonoperatively (mean follow-up 3.39 years), and 10 underwent nephrectomy. Patients underwent radionuclide renal imaging and contrast voiding cystography. Serial ultrasonography was used to obtain measurements of the affected and contralateral kidneys. Blood pressure measurements and serum creatinine levels were available in some patients. RESULTS: Among the 23 nonoperative patients, the affected MCDK involuted in 4 patients during a mean follow-up of 4.5 years at a rate of 1.02 cm/yr (24% annually); 7 kidneys decreased in size at a mean rate of 0.38 cm/yr (5.8% annually); 6 grew at a mean rate of 1.16 cm/yr (9.9% annually); 1 kidney did not change in size; and 5 children were lost to follow-up. The mean size of the contralateral kidneys at birth was 5.3 cm, 2 standard deviations larger than normal. Over time, this relative hypertrophy was maintained at a growth rate of 0.89 cm/yr (18.5% annually). Two patients who had undergone nephrectomy also had serial postoperative ultrasonic renal measurements, and contralateral growth was 0.61 cm/yr (12.16% annually). All but 1 patient had normal blood pressure measurements and serum creatinine levels. CONCLUSIONS: Most MCDKs involute or decrease in size over time, although this may take many years. Contralateral hypertrophy is seen at birth and is maintained during childhood growth, regardless of whether the affected kidney is removed. There is no associated hypertension or malignancy when the dysplastic kidney is left in place.

Follow-Up Studies↗
PubMed1997

Resolution rates of low grade vesicoureteral reflux stratified by patient age at presentation.

PURPOSE: Most children with grades I to III primary vesicoureteral reflux are monitored for years on antibiotic prophylaxis until reflux resolves. While the overall resolution rate of these grades is known, the rates for various patient ages at presentation are unknown. Therefore, we examined resolution rates of these grades for different ages at presentation. MATERIALS AND METHODS: From 1985 through 1990, 168 boys (245 ureters) and 433 girls (590 ureters) with all grades of reflux were enrolled in the study and monitored through the end of 1993. Urine cultures were obtained every 4 months and contrast voiding cystourethrography was repeated every 18 months. Age at presentation was stratified into groups younger than 1, 1 to 3, 4 to 6, 7 to 9, and 10 years and older. Resolution rates were then calculated for grades I to III reflux for each age at presentation. Time to resolution was also evaluated for each age and grade. RESULTS: There were no significant differences between rates of resolution at different ages for each grade. Children less than 10 years old had as high a likelihood of resolution as infants. Neither sex nor bilaterality versus unilaterality was a helpful predictor of resolution. Time to resolution varied widely and it was also not helpful for identifying the cases of reflux that resolved. CONCLUSIONS: Low grade vesicoureteral reflux may not resolve until adolescence and age at presentation is not a reliable predictive factor. Children should remain on prophylaxis for many years unless definitive correction is undertaken.

Age Factors↗
PubMed1997

Experience with vesicoureteral reflux in children: clinical characteristics.

PURPOSE: We reviewed our 9-year experience with a large population of children with vesicoureteral reflux who were evaluated and treated according to contemporary concepts. MATERIALS AND METHODS: From 1985 to 1993 we followed 288 boys and 752 girls with vesicoureteral reflux. If surgery was not performed, patients were on antibiotic prophylaxis and evaluation was done every 18 months with contrast voiding cystography and radionuclide renal imaging. Urine cultures were obtained every 4 months. Two negative voiding cystourethrograms 1 year apart were required to discontinue prophylaxis. RESULTS: The major reasons for initial evaluation were urinary tract infection in 560 children (54%), voiding dysfunction without urinary tract infection in 156 (15%), sibling surveys in 122 (12%) and prenatal hydronephrosis in 23 (2%). In 150 kidneys (10%) in 132 children scarring at presentation was grade 0 in 10 (7%), I in 18 (12%), II in 27 (18%), III in 30 (20%), IV in 48 (32%) and V in 17 (11%). Of these 132 patients 17 presented at ages less than 1 year (13%), 29 at ages 1 to 3 (22%), 50 at ages 4 to 6 (38%), 24 at ages 7 to 9 (18%) and 12 at ages greater than 10 (9%). No new scars were seen in children on prophylaxis without breakthrough infection. After 1 negative voiding cystourethrogram reflux was noted again in 27% of the cases. Breakthrough infections developed in 62 children of whom a third were older than 7 years. Reimplantation in 205 children (20%) was performed for grade IV to V reflux (101), breakthrough infection (62), advanced age (18), large periureteral diverticulum (12) and noncompliance (3). Five boys and 57 girls (30% of all children) had urinary tract infections after successful reimplantation. CONCLUSIONS: Almost half of the children with vesicoureteral reflux have no history of culture proved urinary tract infection. Scarring may be associated with any reflux grade and it may be initially diagnosed at any age. Only half of the scars are noted with higher grades of reflux (IV and V). Continuous prophylaxis prevents new scarring. Breakthrough infections are rare but they can occur at ages greater than 7 years. Two consecutive negative cystograms are necessary before discontinuing prophylaxis. Children should be monitored after reimplantation for recurrent urinary tract infection.

Child↗
PubMed1996

Vesicoureteral reflux: practical aspects of evaluation and management.

The efficacy of both medical and surgical therapy for vesicoureteral reflux (VUR) has been well established. Controversy remains, however, regarding who should be evaluated for the presence of VUR, who should undergo corrective surgery, who should be treated medically and for how long. Medical treatment requires many years of continuous antibiotic prophylaxis, so compliance with therapy is essential. Many children are lost to followup, however, and remain untreated after a medical regimen is started. This large number of untreated children raises issues of the appropriateness of blanket therapeutic recommendations for all children with VUR and challenges the clinician to devise more effective treatment strategies.

Anti-Bacterial Agents↗
PubMed1996

An analysis of social and economic factors associated with followup of patients with vesicoureteral reflux.

PURPOSE: Nonsurgical treatment of vesicoureteral reflux requires antibiotic prophylaxis and long-term surveillance. We examined factors that affect followup compliance and influence quality of care in these children. MATERIALS AND METHODS: We retrospectively reviewed the records of 288 boys and 742 girls with vesicoureteral reflux. RESULTS: Of the children treated nonsurgically for vesicoureteral reflux 34% were lost to followup and the majority (80%) were not monitored beyond the 1-year followup appointment. Older maternal age (36 years or older) was significantly associated with improved followup compliance. Paternal age, primary physician type, medical insurance type, income, education level and environment (urban, suburban or rural) were not significant. CONCLUSIONS: Approximately a third of children treated nonsurgically for vesicoureteral reflux will be lost to followup. Only older maternal age predicts for good compliance. Preconceptions about compliance on the basis of other factors, such as socioeconomic status and primary physician type, may be incorrect. Furthermore, the notion that certain forms of medical insurance plans may help to promote followup may also be unsupported. These children would benefit from efforts to improve compliance with a medical regimen or early correction of reflux.

Child↗
PubMed1996

Sibling reflux: a dual center retrospective study.

PURPOSE: Siblings of index patients with vesicoureteral reflux are known to have an increased incidence of reflux. Previous reports may be biased due to significantly more female siblings undergoing screening. In addition, it has been suggested that screening is unnecessary in older children. MATERIALS AND METHODS: We retrospectively reviewed the records of probands with vesicoureteral reflux. A total of 422 families comprising 622 siblings was identified at our centers from 1985 to 1994. Of the 255 boys and 277 girls newborn to 16 years old (mean age 6.2 years) 85% were evaluated. Almost 43% of the probands (225) were older than 7 years. RESULTS: Vesicoureteral reflux was noted in 144 siblings (52 boys and 92 girls, 27%). The majority had low grade reflux but in 111 (77%) maximum reflux grade was II or III. Reflux nephropathy was demonstrated on a nuclear renal scan in 18 of the 132 tested siblings (13.6%). In all of these children reflux was grades II to IV and 27% were older than 10 years. CONCLUSIONS: When vesicoureteral reflux is discovered, all siblings should be considered for screening. The evaluation of older siblings remains controversial, since they comprise only a small fraction of all siblings with reflux but may have a significant portion of reflux nephropathy. There was a 27% overall incidence with a 33% rate in girls. The incidence of reflux in siblings decreased after age 7 years but reflux nephropathy was identified even in the older children.

Adolescent↗
PubMed1995

Regional renal blood flow measurements using radioactive microspheres in a chronic porcine model with unilateral vesicoureteral reflux.

95Niobium labeled radioactive microspheres were used to determine regional renal blood flows in a porcine model of chronic sterile vesicoureteral reflux. Unilateral vesicoureteral reflux was surgically created in 5 mini-pigs and regional renal blood flows were determined by microsphere injection 6 months later. The contralateral nonrefluxing kidney acted as a control. There was a significant reduction of flow in the inner cortical regions of the middle (78% of control, p < or = 0.0437) and lower poles (69% of control, p < or = 0.0274), and the juxta-medullary cortical region of the lower pole (67% of control, p < or = 0.0124). There was no difference in flow in the other regions or when comparing whole kidneys. There were no differences between refluxing and nonrefluxing kidneys when comparing ratios of inner to outer cortical flow level by level. These observations are in contrast to those in acutely created vesicoureteral reflux in a porcine model, which had no significant differences in flow in any region using the microsphere technique. Decreases of blood flow in certain cortical regions may help explain some of the physiological changes in vesicoureteral reflux in children and experimental models of reflux.

Animals↗
PubMed1995

Intrascrotal epidermoid cyst with extension into the pelvis.

An 8-year-old boy presented with an asymptomatic extratesticular, scrotal epidermoid cyst with extension across the urogenital diaphragm into the pelvis. While routine contrast studies and ultrasound were performed, magnetic resonance imaging was most useful in depicting the anatomical boundaries of the lesion, including the intrapelvic extension. Complete excision was performed transcrotally. The lesion is histologically indistinguishable from epidermoid cysts found elsewhere in the external genitalia, that is the penis, scrotum or testis. The etiology is unknown but it may represent a monolayer teratoma of germ cell origin or abnormal embryological closure of the median raphe.

Child↗
PubMed1994

Type III posterior urethral valves: presentation and management.

The clinical and radiographic presentation of infants with type III posterior urethral valves help to distinguish them from patients with the more common type I valves. The diaphragmatic valvular obstruction may make catheterization impossible. Percutaneous cystography can confirm the diagnosis and allow for short-term decompression. The presence of smooth-walled bladders with narrow posterior urethras is unique to type III valves but is not always present. Type III valves present within a spectrum of clinical severity; however, the majority involve significant renal impairment. The prognosis for survival and renal function appears poorer for patients with type III valves than for those with type I valves.

Child, Preschool↗
PubMed1994

Two-stage repair for severe hypospadias.

In 39 patients a 2-stage modified Belt-Fuqua repair was performed for severe hypospadias and chordee. Patient age at initial surgery averaged 2 years and stage 2 was done 7 months later. Testosterone was given before stage 1 to 22 patients (56%) and before both stages to 13 (33%). Of 5 patients with intersex 2 had mixed gonadal dysgenesis, 1 was a true hermaphrodite and 2 were 46 XX male subjects. The preoperative meatal location was subglanular in 9 cases, mid shaft in 8, proximal shaft in 2, penoscrotal in 15 and perineal in 5. Those with subglanular meatus had hypoplastic distal urethras and severe chordee. A dorsal Nesbit procedure for chordee correction was done in 24 cases (62%). Neourethral length ranged from 3 to 7 cm. (average 4 cm.) and average followup was 16 months. Neourethral diverticula developed in 8 cases (21%) and they were repaired uneventfully an average of 7 months (range 2 to 24) after stage 2. Minor urethral strictures (3 distal and 4 proximal) were treated with a single visual internal urethrotomy and there was 1 (2.5%) urethrocutaneous fistula. All children had excellent cosmetic and functional outcomes. A staged approach allows for cosmetic reconstruction of the glans and mucosal collar during stage 1 and offers 2 opportunities to augment penile size with testosterone. Bladder or buccal mucosal grafts are avoided since the prepuce is always adequate. There are no hypospadias deformities, penile shaft torsion or asymmetry. Fistula formation is minimal and strictures are minor. The 2-stage repair remains a safe, reliable alternative for boys with severe hypospadias.

Child↗
PubMed1993

Ureteral reimplantation in infants.

Between 1984 and 1990, 30 infants (46 ureters) 8 weeks to 6 months old (mean age 4 months) underwent ureteral reimplantation. Weight at operation ranged from 4.9 to 9.5 kg. (mean 6.9). Underlying abnormalities were primary vesicoureteral reflux (28 ureters), primary ureterovesical junction obstruction (11), ectopic ureterocele (4) and ectopic ureter (3). Patients with reflux underwent surgery because of high grade reflux (grade IV or V) or breakthrough infection. Infants with primary ureterovesical junction obstruction underwent obstructive diethylenetriaminepentaacetic acid diuretic renograms. Reimplantations performed included 44 Glenn-Anderson advancements, 1 Cohen cross-trigonal advancement and 1 Politano-Leadbetter procedure. Of the ureters 30 (65%) were tapered intravesically. Ureteral stents were used in all instances. Transient ureteral obstruction developed in 2 children following stent removal and 1 required temporary percutaneous nephrostomy drainage. No permanent ureterovesical obstruction was noted in any patient. Followup at 18 months revealed no postoperative reflux in 43 of 46 ureters (93%). One infant required repeat reimplantation to correct a vesicoureteral fistula and the remaining 2 patients (2 ureters) with low grade reflux (grade I and II) are being observed. Surgery was successful in 27 of 30 tapered ureters (90%) and in all 16 of the nontapered ureters (100%). While the majority of infants with ureterovesical junction abnormalities may be observed, some may require surgery. Reimplantation, when necessary in this age group, can be performed with a high degree of success and diverting procedures such as vesicostomy or ureterostomy can be avoided.

Female↗
PubMed1993

Effects of neurogenic bladder dysfunction in utero seen in neonates with myelodysplasia.

Twenty neonates with myelodysplasia were prospectively evaluated during the first month of life with urodynamic studies, contrast voiding cystourethrograms (VCUG) and renal ultrasound scans. Ten of 20 infants had abnormal VCUGs--6 with vesicoureteric reflux (VUR) and 4 with bladder trabeculation alone. Only 2/20 neonates had abnormal ultrasounds--both with hydroureteronephrosis secondary to VUR. Elevated leak point pressure (LPP) and/or detrusor sphincter dyssynergia (DSD) were present in 10/20 infants--6 with elevated LPP and DSD, 3 with elevated LPP alone and 1 with DSD alone. Eight of 10 neonates with DSD or elevated LPP had abnormal VCUGs--4 with VUR and 4 with bladder trabeculation alone. Conversely, 8/10 neonates without DSD or elevated LPP had normal VCUGs. Contrast VCUG performed shortly after birth, therefore, is essential for the discovery of bladder trabeculation and reflux. There is a strong correlation between an abnormal VCUG and the presence of DSD and elevated LPP, suggesting that neurogenic bladder dysfunction in utero can lead to these structural abnormalities.

Abnormalities, Multiple↗
PubMed1992

Vesicoureteral reflux in children with and without a history of urinary tract infection: a comparative analysis.

Eighty-eight children who were discovered to have vesicoureteral reflux were prospectively studied over a two-year period. Two groups were compared: 49 who presented with a urinary tract infection and 39 who were identified through prospective screening. Based on the distribution of grade and the presence of parenchymal scarring, the severity of vesicoureteral reflux was comparable in the two groups. Of note, more males with reflux were identified in the noninfected group, whereas sex distribution was almost equal in the infected group. Ultrasound alone was found to be highly inaccurate in identifying reflux or parenchymal changes. In conclusion, screening of at-risk groups of children without a history of urinary tract infection may identify patients with clinically significant vesicoureteral reflux.

Child↗