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Biomedical subjects

R L Lebowitz

Publications and source records attributed to R L Lebowitz.

At least 55 records · Page 3Linked to original sources

What's new in pediatric uroradiology.

The diagnosis and treatment of infants and children with urinary tract abnormalities have recently been affected by three developments. First, hydronephrosis can be detected in the fetus on obstetrical ultrasonography. Prenatal detection has resulted in a marked increase in the number of neonates referred for uroradiologic evaluation. Ureteropelvic junction (UPJ) obstruction, ureterovesical junction obstruction (UVJ), and reflux have been found to be the most common causes of hydronephrosis. Prophylactic antibiotics begun soon after delivery can prevent infection and its sequelae. Second, multicystic dysplastic kidney can now be accurately diagnosed preoperatively by a combination of ultrasonography and renal scintigraphy. This diagnostic certainty makes the decision to remove such a kidney a philosophical one. Third, it has been learned that reflux is sometimes familial. Nuclear cystography is an accurate and efficient method for screening asymptomatic family members.

Child↗

Congenital obstructed megaureters in early infancy: diagnosis and treatment.

Fetal screening during maternal ultrasonography has changed the mode and age of presentation of congenital uropathies, particularly congenital obstructed megaureter. We studied 47 infants less than 8 months old with primary obstructed megaureter. Surgical correction in 42 patients with moderate to severe obstruction was performed at a mean age of 1.8 months in those detected prenatally and 3.8 months in those presenting after birth. All infants showed functional and structural urographic improvement with a mean followup of 2.3 years. Reflux was seen postoperatively in 8 patients, which subsided spontaneously in 3, continues to be followed in 2 and resulted in repeat reimplantation in 3. Five infants had mild obstruction, which was managed nonoperatively and 2 showed progressive obstruction, which required repair at ages 20 and 28 months. Repair of obstructed megaureters in early infancy improves renal drainage and offers the potential for preventing renal damage before the development of symptoms or infection. With proper attention to detail, excellent results may be achieved.

Dilatation, Pathologic↗

Strictures in the ileal portion of ileocecal conduits in children and young adults.

Patients with ileocecal conduits are at risk for development of late complications. We present 3 patients who had strictures in the ileal portion of the ileocecal conduit, leading to deterioration of the upper urinary tract. The pathogenesis of these strictures appears to result from chronic inflammation. Long-term periodic upper urinary tract screening with ultrasonography is important for early detection of this complication. When new or increasing hydronephrosis is found a loopogram or antegrade pyelogram (if the ileocecal valve is competent) should be performed to evaluate the ileal portion of the ileocecal conduit.

Adolescent↗

Lower pole ureteropelvic junction obstruction and incomplete renal duplication.

The rare finding of lower pole ureteropelvic junction obstruction and incomplete renal duplication is discussed in 5 children. The children were divided into 2 groups, with short (less than 0.5 cm.) and long (greater than 4 cm.) lower ureteral segments. Short ureteral segment obstruction was managed by total excision of the narrow ureteral segment and end-to-side pyeloureterostomy. Obstructions associated with long lower ureteral segments were treated by excising the ureteropelvic junction and performing a standard Anderson-Hynes pyeloplasty. A thorough preoperative evaluation is helpful for successful management.

Child↗

Spontaneous extraperitoneal rupture of the urinary bladder in children.

The authors describe two children who had spontaneous extraperitoneal rupture of the urinary bladder into the retropubic space secondary to acute urinary retention following lower urinary tract surgery. One also had urinary ascites. In one, the urinoma was initially mistaken for the bladder during ultrasonography. In both cases, the diagnosis of bladder rupture was not considered initially because of a lack of familiarity with the occurrence of this entity in children.

Child, Preschool↗

Neonatal hydronephrosis due to primary vesicoureteral reflux: trends in diagnosis and treatment.

The records were reviewed of the 25 neonates found to have hydronephrosis due to primary vesicoureteral reflux at the authors' hospital in the 6 1/2-year period from January 1981 to June 1987. Modes of discovery and investigation, detection of associated lesions, treatment, and errors in both diagnosis and management were evaluated. Twenty-one of the neonates were boys. Fourteen cases were found at fetal screening, and the infants were asymptomatic. Inappropriate maternal/fetal intervention occurred in four cases: Three were incorrectly thought to have posterior urethral valves. The increased number of neonates found to have reflux is attributable to the widespread availability of obstetric ultrasonography and early screening of infants at risk for urinary tract abnormalities. Since the pathophysiologic characteristics of reflux are well understood, appropriate postnatal therapy can be instituted without delay.

Female↗

Ectopic ureterocele without ureteral and calyceal dilatation (ureterocele disproportion): findings on urography and sonography.

Eight infants and children (six girls) were seen over a 13-year period with duplex collecting systems and ectopic ureteroceles. In each, there was striking dissimilarity in size between the large ureterocele and its diminutive ureter and calyces. The upper moiety did not function and, except for the ureterocele, the indirect urographic and direct sonographic signs of duplication were absent or subtle. We call this entity ureterocele disproportion. Seven patients presented with urinary infection and one was found to have hydronephrosis of a dilated lower moiety in utero. Five had ipsilateral lower-pole reflux, which ranged in degree from 3 to 5 (on a scale of 1-5). Two had bilateral duplication; one of these had a typical contralateral ectopic ureterocele. The diagnosis of ureterocele disproportion was strongly suggested by urography and sonography and was confirmed at cystoscopy by direct puncture of the ureterocele and opacification of the upper moiety. All had surgery. The approach varied and depended on the status of the lower moiety and the contralateral kidney. One had incision of the ureterocele only. Five with lower-pole reflux had excision of the ureterocele and ipsilateral common-sheath reimplantation.

Child, Preschool↗

Primary vesicoureteral reflux in blacks with posterior urethral valves: does it occur?

Primary vesicoureteral reflux (VUR) is thought to be largely independent of obstruction. Therefore, in patients with urethral obstruction due to posterior urethral valves (PUV) the occurrence of VUR is coincidental. In addition, primary VUR is reported to be uncommon in black children. If these two premises are correct, then primary VUR should be rare in black males with PUV. To test this hypothesis, we reviewed the medical records and radiographs of 43 males with PUV. Twenty-one of the 37 non-black males with PUV had VUR, of which 67% was primary and 33% was secondary. Three of the six blacks with PUV had VUR of which all was secondary. Thus, blacks with PUV lend credence to the theory that primary VUR is not caused by obstruction and support the observation that primary VUR is rare in black children, even those with PUV.

Adolescent↗

Ureteropelvic junction obstruction in the neonate.

The widespread use of maternal ultrasonography has resulted in an increasing number of asymptomatic newborns being diagnosed with hydronephrosis. A total of 89 neonates with hydronephrosis secondary to ureteropelvic junction obstruction have been referred for evaluation and treatment during the last 6 years. In the majority the condition was diagnosed readily with ultrasonography, voiding cystography and excretory urography. Twenty-five per cent underwent more quantitative assessment using nuclear renal imaging. Only 2 patients (8 per cent) had a percutaneous study. Early reconstruction was performed in 75 per cent of the patients and it proved to be safe and effective. Twenty-three neonates were followed nonoperatively. One patient (4 per cent) demonstrated clinical deterioration necessitating later surgical intervention. Careful surveillance is mandatory in all infants followed nonoperatively.

Female↗

The changing neurourologic lesion in myelodysplasia.

Seventy-nine newborns with myelodysplasia were followed up for 1 1/2 to six years with serial roentgenographic, neurologic, and urodynamic evaluations. Twenty-nine infants (37%) demonstrated changes in external urethral sphincter innervation during the first three years of life. Of the group who changed, 896% (25/29 infants) did so in the first year, 10% (3/29 infants) in the second year, and 4% (1/29 infants) in the third. The risk factor for change was 32%, 6%, and 2%, respectively, during each of these three years. Fifteen infants (19% of the total) experienced neurourologic deterioration while 14 infants (18%) improved. Seven newborns underwent a second neurosurgical procedure resulting in improvement in four, stabilization in two, and further deterioration in one. These findings underline the importance of early and continued neurologic and urologic surveillance in children with myelodysplasia because it is a dynamic disease process.

Electromyography↗

Nonutility of cineurograms in children with congenital heart disease.

Cineurography is often performed after cineangiocardiography to look for occult congenital urinary tract disease. The accuracy of cineurography was investigated in 171 patients by comparing cineurograms with renal sonograms. One hundred fifteen cineurograms (67%) showed both kidneys well enough to allow assessment of renal structure and function and the results were confirmed in 112 by ultrasonography; 3 cineurograms yielded false-positive results. Limited or no information was obtained from cineurograms of 56 patients (33%) because of nonvisualization or poor visualization of 1 or both kidneys. Of the 11 patients (6%) with urinary tract disease, only 3 were correctly assessed by cineurography. Ultrasonography discovered all 11 renal abnormalities and produced only 1 false-positive result. These data indicate that cineurography is a poor screening test and should be abandoned. When uroradiologic screening is necessary for high-risk patients, sonography is recommended.

Adolescent↗

Renal dysgenesis and cystic disease of the kidney: a report of the Committee on Terminology, Nomenclature and Classification, Section on Urology, American Academy of Pediatrics.

We believe that the confusion regarding abnormal renal development could be reduced by more precise terminology. Therefore, we suggest precise definitions for dysgenesis, hypoplasia, dysplasia, hypodysplasia, aplasia and agenesis of the kidney. We suggest the term reflux nephropathy be a generic label for any instance of abnormal renal morphology (gross or microscopic) associated with vesicoureteral reflux. Hypoplasia and hypodysplasia can be subclassified on the basis of associated urological criteria. There have been many previous attempts to classify cystic disease of the kidney but none has been accepted collectively by pathologists, urologists, nephrologists and radiologists. On the basis of known patterns of inheritance, a classification is outlined in which renal cystic disease is divided into 2 major groups: genetic and nongenetic. Each entity is discussed.

Classification↗

Urinary tract infection in children: putting radiology in its place.

Bacterial infection of the child's urinary tract can be viewed as a phenomenon in which bacterial virulence factors outweigh host resistance mechanisms. Structural abnormalities that compromise the host account for only a small part of the picture, but it is important to discover these abnormalities, and uroradiologic examinations can do this superbly. There are many ways to image the kidneys and the lower urinary tract, but more important than debating which of these tests to use is deciding who should be studied, why, and when, and what it means when an abnormality is discovered.

Bacterial Infections↗

Stones in the urinary bladder in children and young adults.

Bladder stones were diagnosed in 22 children and young adults at The Children's Hospital, Boston, from 1969 to 1985. One half of the patients were less than 12 years old (mean, 11.9 years). One or more lithogenic factors were implicated in all but two. The most common causes were the presence of an intravesical foreign body, infection with Proteus (a urea-splitting organism), exstrophy of the bladder, and the presence of intestinal mucosa in the urinary tract. The radiologic features of the stones were not specific, and no special techniques were needed to identify them. Heightened awareness of patients at risk will lead to prompt diagnosis and treatment.

Adult↗

Neonatal hydronephrosis in the era of sonography.

During a 6-year period (1979-1985), 142 neonates with significant hydronephrosis were seen. Seventy-eight percent of the cases were discovered on fetal screening during obstetric sonography. Maternal/fetal intervention was virtually never indicated and most babies were asymptomatic. The most common conditions found were obstruction of the ureteropelvic junction (41%), obstruction of the distal ureter (usually primary megaureter) (23%), upper-pole hydronephrosis associated with duplex anomalies (13%), and posterior urethral valves (10%). Seventeen neonates with multicystic dysplastic kidney were seen (three per year or one for every eight with hydronephrosis). In comparison, during the 30-year period, 1947-1977, 146 neonates with significant hydronephrosis were seen. Most cases were discovered because the patients had signs and/or symptoms--either an abdominal mass (an enlarged kidney or bladder) or urosepsis. The three most common conditions were obstruction of the ureteropelvic junction (22%), posterior urethral valves (19%), and ectopic ureterocele (14%). During this period, 53 neonates with multicystic dysplastic kidney were discovered (two per year or one for every three with hydronephrosis). The dramatic increase in the number of neonates found to have hydronephrosis is primarily due to the widespread use of obstetric sonography and concomitant fetal screening. The pattern of causes before 1979 represented the incidence of symptomatic lesions. The current pattern more accurately reflects the true incidence of congenital anomalies of the urinary tract.

Humans↗

The coexistence of obstruction at the ureteropelvic and ureterovesical junctions.

Obstructions at the ureteropelvic junction and ureterovesical junction were found to coexist in 14 children seen over an 11-year period. The coexistence of these two conditions made the diagnosis of each difficult. In only three children were both diagnoses made preoperatively; in the others, the second diagnosis was either suspected at surgery or was made on postoperative uroradiologic studies. Of five children in whom the initial diagnosis was obstruction at the ureteropelvic junction, only two have needed surgery for obstruction at the ureterovesical junction. Seven children had an initial diagnosis of obstruction at the ureterovesical junction, and all required subsequent pyeloplasty to relieve coexisting obstruction at the ureteropelvic junction. Therefore, our experience suggests that when both obstructions are known to exist or are suspected preoperatively, it is advisable to repair the stenosis at the ureteropelvic junction first, as distal ureteral surgery may not be necessary.

Child↗