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Biomedical subjects

R L Lebowitz

Publications and source records attributed to R L Lebowitz.

At least 91 records · Page 5Linked to original sources
PubMed1984

The megacystis-megaureter syndrome.

The term megacystis-megaureter describes the radiologic appearance of a large capacity thin-walled bladder and massive primary vesicoureteral reflux. The pathophysiology of these massively dilated ureters and the large capacity bladder is the constant recycling of large volumes of refluxed urine. We treated 29 children between 1 day and 13 years old with this syndrome. Urinary tract infection was present in 74 per cent of the cases. Of these children who presented before 1975, 14 were misdiagnosed primarily as having bladder outlet obstruction, which resulted in inappropriate treatment in 13 and renal deterioration in 5. The remaining 15 children treated after 1975 by means of antireflux surgery alone have remained well with stable renal function and virtual elimination of residual urine. Initial therapy should be aimed at correction of the massive reflux, rather than surgical reduction of bladder capacity or relief of presumed bladder outlet obstruction.

Child↗
PubMed1984

Refluxing urethral ectopic ureters: recognition by the cyclic voiding cystourethrogram.

Reflux into an ectopic ureter that opens into a girl's urethra has been difficult to demonstrate and has been thought to occur in only about a third of the patients with this anomaly. In an attempt to more reliably demonstrate this reflux, 12 girls aged 1 day to 6 years, who were suspected of having an ectopic ureter, were studied using a method of cyclic filling and voiding during the cystourethrogram. Reflux into their urethral ectopic ureter was shown in 11 (92%). The technique of cyclic voiding cystourethrography should be used in all girls in whom an ectopic ureter is suspected, either because of signs or symptoms or because of a dilated upper pole of a duplex collecting system seen on an excretory urogram or a sonogram. It should also be used when a conventional voiding cystourethrogram has shown no or only minimal reflux.

Child↗
PubMed1984

The coexistence of primary megaureter and reflux.

Primary megaureter is a common cause of obstruction of the urinary tract in children. Vesicoureteric reflux is a common lower-tract abnormality. The seemingly paradoxical coexistence of these entities was found to occur nine times over the 10-year period, 1973 to 1983 (in about 2800 children with reflux and about 75 children with primary megaureter). This coexistence should be suspected on voiding cystourethrography when the juxtavesical segment of the megaureter is normal in caliber, the refluxed contrast agent is diluted by urine that is trapped in the ureter, and drainage of refluxed contrast agent into the bladder is impeded. The diagnosis can be confirmed by excretory urography with a catheter draining the bladder to temporarily prevent the reflux. The surgical treatment consists of resection of the distal aperistaltic segment and reimplantation of the ureter.

Child, Preschool↗
PubMed1983

Trends in pediatric uroradiology.

Excretory urography, conventional and radionuclide voiding cysto(urethro)graphy, ultrasonography, radionuclide renal imaging and computed tomography are all currently readily available in most locales for the evaluation of the child's urinary tract. It is the responsibility of the radiologist to determine which studies are best for which children and the order in which they should be performed to minimize "cost" while maximizing the information obtained. A description of such an approach and its consequences are presented.

Adolescent↗
PubMed1983

Fetal and neonatal hydronephrosis.

Maternal ultrasonography makes it possible to easily detect hydronephrosis in the fetus, and therefore fetal "screening" should be part of every obstetrical ultrasonogram. However, the mere presence of fetal hydronephrosis virtually never means that either fetal intervention or early delivery is warranted. The importance of fetal case-finding is that it enables us to promptly (and electively) evaluate and treat the asymptomatic neonate before infection or other complications occur.

Female↗
PubMed1983

Prolonged dense nephrograms in battered children. Suspect rhabdomyolysis and myoglobinuria.

Prolonged, dense nephrograms were seen on intravenous urography in 5 cases of child abuse presenting with possible renal injury. Each child had oliguria, elevated muscle enzymes, and pigmented urine positive for blood, but without red cells on microscopic examination. These findings are suggestive of myoglobinuria. The abnormalities resolved with appropriate fluid and electrolyte management. This complication of child abuse, not previously emphasized, may be suggested by the urographic findings. Possible factors contributing to the dense nephrograms are presented.

Child↗
PubMed1983

The coexistence of ureteropelvic junction obstruction and reflux.

Since ureteropelvic junction obstruction is the most common upper urinary tract problem in children, and vesicoureteral reflux the most common lower tract problem, it is not surprising that these entities sometimes coexist in the same child. Over a 10 year period this uncommon phenomenon has been noted 21 times (in about 2,800 children with reflux and 200 children with ureteropelvic junction obstruction). Significant ureteropelvic junction obstruction in association with mild reflux can mimic severe reflux, but the operation needed is not reimplantation but pyeloplasty. Conversely, when significant ureteropelvic junction obstruction coexists with significant reflux, both operations may be necessary, but the order in which they are done (pyeloplasty first) seems to be crucial. Voiding cystography with appropriate postvoid drainage films, excretory urography, often with a catheter draining the bladder to prevent reflux, and provocative diuretic excretory urography and/or renography can determine that ureteropelvic junction obstruction does coexist and quantitate the severity of each problem.

Adolescent↗
PubMed1983

Interlabial masses in little girls: review and imaging recommendations.

When an interlabial mass is seen on physical examination in a little girl, there is often confusion about its etiology, its implications, and what should be done next. Five common interlabial masses, which superficially are strikingly similar, include a prolapsed ectopic ureterocele, a prolapsed urethra, a paraurethral cyst, hydro-(metro)colpos, and rhabdomyo sarcoma of the vagina (botryoid sarcoma). A prolapsed ectopic ureterocele occurs in white girls as a smooth mass which protrudes from the urethral meatus so that urine exits circumferentially. A prolapsed urethra occurs in black girls and resembles a donut with the urethral meatus in the center. A paraurethral cyst is smaller and displaces the meatus, so that the urinary stream is eccentric. Hydro(metro)colpos from hymenal imperforation presents as a smooth mass that fills the vaginal introitus, as opposed to the introital grapelike cluster of masses of botryoid sarcoma. Recommendations for efficient imaging are presented.

Adolescent↗
PubMed1981

Localized intra- and retroperitoneal gas collections following intraoperative use of surgical gelatine sponge.

Following recent intra- or retroperitoneal surgery, four children in whom hemostasis was obtained by means of abundant use of surgical gelatine sponge, displayed unusual bubbly air collections in the region of the operation. Three of them had vague inflammatory symptoms and signs, while in the fourth the gas was discovered incidentally. The connection between the radiological finding and the hemostatic agent is presented. In the typical case manifesting a mild clinical course, knowledge of this association helps to guard against the diagnosis of abscess, and subsequent unnecessary reoperation can be avoided.

Child↗
PubMed1981

Ureteral ectopia in infants and children.

The diagnosis of ureteral ectopia may be suspected in the girl who wets constantly or in the young boy with epididymitis. More commonly, however, the diagnosis is made during evaluation of the child with urinary tract infection. The ectopic ureter is most often associated with a poorly functioning dysplastic upper pole of a duplex collecting system and in this instance it is best managed by upper pole heminephrectomy and partial ureterectomy. When associated with a single collecting system, ureteral reimplantation can often be performed if salvageable function is demonstrated by a preoperative renal scan. Based on our experience with 48 ectopic ureters in 41 children operated on during the last 11 years, the correlation of the diagnostic findings and surgical approaches to this entity are discussed.

Child↗
PubMed1981

Infection does not cause reflux.

Vesicoureteric reflux in children was originally considered to be a secondary phenomenon, caused by distal obstruction. We now know, however, that most children with vesicoureteric reflux are not obstructed. More recently, urinary tract infection has been thought to be the cause of most vesicoureteric reflux. To test this hypothesis, the results of 601 voiding cystourethrograms with simultaneous culture of the urine (in children), over a 12 month period were analyzed. Of the 34% (204/601) with vesicoureteric reflux, 88% (179/204) had sterile urine and 12% (25/204) were infected. Of the 66% (397/601) without reflux, 90% (357/397) had sterile and 10% (40/397) infected urine. These data do not support the concept that vesicoureteric reflux is secondary to infection in these children. On the contrary, it suggests that reflux and urinary tract infection are independent variables that often coexist. It is concluded that vesicoureteric reflux is a primary phenomenon and is due to incompetence of the ureterovesical junction.

Child↗
PubMed1981

Effect of low dose irradiation on renal enlargement in children following nephrectomy for Wilms' tumor.

The effect of low dose irradiation on subsequent compensatory renal enlargement in a group of children operated upon with unilateral nephrectomy for Wilms' tumor is reported. Comparison groups were children whose remaining kidney received either no direct irradiation or irradiation to only the upper portion of the kidney. The rate of growth of the kidney in the irradiated group was slightly less but this was not statistically significant. Thus, radiation therapy in children with Wilms' tumor, so crucial to optimum survival, does not seem to cause significant renal toxicity.

Child↗
PubMed1980

Misleading appearances in pediatric uroradiology.

Certain misleading appearances are peculiar to pediatric uroradiology. The most frequently encountered pitfalls are related to the bladder, to vesicoureteral reflux, and to the duplicated collecting system. The bi-chambered nature of the child's bladder, and the rapid settling of contrast material to the most dependent portion causes many pitfalls in diagnosis. When the child is prone, normal ureters may seem to be ectopic, and ureteroceles may become invisible. When the child is supine, the volume of urine in the bladder may be grossly under-estimated. Reflux can mimic function at urography. The dynamic nature of reflux leads to under-estimation of its presence and degree on the IVP and static cystogram. Reflux into an already dilated system can lead to over-estimation of its degree. Aberrant micturition with rapid refilling of the bladder can simulate incomplete emptying. The diagnosis of "ectopic ureterocele" is based on indirect evidence. Any condition that affects the urinary apparatus in the same way will have a similar appearance. A hugh ureterocele may have a small ureter, and massive reflux into a lower pole ureter may make the diagnosis of duplication difficult. Ureteroicele "look-alikes", and effacement or intussusception of the ureterocele are cystographic pitfalls. Lower pole ureteropelvic junction obstruction and Wilms tumor in the lower portion of a kidney can have surprisingly similar appearances.

Adult↗
PubMed1980

Urethral narrowing in region of external sphincter: radiologic-urodynamic correlations in boys with myelodysplasia.

Narrowing of the urethra in the region of the external sphincter as seen during voiding cystourethrography has routinely been termed sphincter spasm. This diagnosis was found to be incorrect in a significant percentage of boys with myelodysplasia. Thirty boys with myelodysplasia and dysfunction of the lower urinary tract, in whom voiding cystourethrography revealed narrowing in the area of the external sphincter, underwent urodynamic evaluation. Incoordination of the bladder and the sphincter (sphincter spasm) was found in only 16 (52%). In the other 14 (48%), there was either relaxation of the sphincter or absent electrical activity; atrophy and fibrosis of the striated muscle of the external sphincter (documented in six patients) probably resulted from chronic denervation. Thus, voiding cystourethrography only reveals narrowing of the urethra in the region of the external sphincter. However, when it is combined with urodynamic evaluation, the dynamics of the function of the sphincter can be defined and a rational approach to treatment planned.

Child↗