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Biomedical subjects

R L Lebowitz

Publications and source records attributed to R L Lebowitz.

At least 19 recordsLinked to original sources
PubMed1992

Urinary tract infection in infants in spite of prenatal diagnosis of hydronephrosis.

The efficacy of preventing neonatal urinary infection in infants by diagnosing hydronephrosis in the fetus on obstetrical ultrasonography was studied. 426 infants had uroradiologic evaluation between 1984 and June 1991 because they had hydronephrosis detected in utero. Thirteen with posterior urethral valves were excluded. Of the remaining 413, 13 (3.1%) presented with urinary infection in the first 6 months of life. Ten of the 13 were boys and 7 were not circumcised. Eleven of the 13 infants less than 2 months old were formula-fed. The causes of hydronephrosis were reflux alone in 6, ureteropelvic junction obstruction in 6 (with coexisting ipsilateral reflux in 4), and primary megaureter in 1. Ultrasonography alone was insufficient to exclude reflux. Amoxicillin-resistant bacteria were the causative organisms in all 10 for whom bacteriology data was available. Four categories of management failure were identified: 1) failure of communication of the prenatal findings, 2) antibiotics not prescribed, 3) antibiotics prescribed but not administered, and 4) infection in spite of continuous antibiotic prophylaxis. Uncircumcised formula-fed male infants with reflux seemed to be at special risk for infection.

Anti-Bacterial Agents↗
PubMed1992

Urolithiasis in a children's hospital: 1985-1990.

We performed a retrospective study of patients who had urinary tract stones and were seen at our hospital from 1985-1990. The study was intended to determine the prevalence of urolithiasis and optimal approaches to imaging. Clinical data and imaging studies of 87 patients were reviewed. The mean age was 15.7 years with a range of 3 months to 44 years. Fifty-four percent of patients were male. Most patients had a known predisposing cause for urolithiasis; patients with myelodysplasia and structural urologic problems predominated. Plain films were performed in 77 patients; 57% showed stones. Ultrasonograms were performed in 71 patients; 77% showed stones. Excretory urograms (EU) were performed in 49 patients; 84% showed either stones or their effect on the urinary tract. Computed tomographic (CT) scan was performed in 25 patients; all showed stones.

Adolescent↗
PubMed1992

Primary megaureter in infants and children: a review.

Primary megaureter is a common cause of obstructive uropathy in children. The imaging studies and records of 75 infants and children with primary megaureter seen at Children's Hospital were reviewed. We describe our findings and illustrate the clinical presentations, diagnosis, and treatment of this entity.

Child↗
PubMed1992

Prenatal diagnosis of the megacystis-megaureter association.

A total of 11 male neonates with hydronephrosis and a large bladder in utero had the megacystis-megaureter association. Prenatal ultrasound findings included bilateral hydroureteronephrosis; a large, smooth, thin-walled bladder, and normal volume of amniotic fluid. Postnatal studies demonstrated grades 4 to 5 bilateral reflux, a large bladder without obstruction and in 2 infants nonfunction of a kidney or renal moiety. Of 7 infants initially managed nonoperatively 5 have undergone surgery due to persistent reflux or breakthrough urinary infections. The prenatal diagnosis of the megacystis-megaureter association can be suspected with reasonable accuracy. Prompt postnatal continuous antibiotic prophylaxis and uroradiological confirmation allow for nonemergency management of this condition with excellent results.

Female↗
PubMed1992

The detection and characterization of vesicoureteral reflux in the child.

Voiding cystourethrography or radionuclide cystography should be performed in the child in whom it is important to know whether reflux is present. Voiding cystourethrography is more accurate in characterizing and grading reflux, and monitoring is intermittent. Conversely, radionuclide cystography uses a lower radiation dose and its continuous monitoring leads to fewer false negative results but its ability to characterize reflux is poor. The performance of voiding cystourethrography or radionuclide cystography to detect reflux is an art as well as a science. These tests are done best by those who are experienced and interested in imaging the urinary tract of the child. At our hospital we perform voiding cystourethrography in all young children with urinary tract infection to detect and precisely characterize reflux to enable intelligent planning of management. In older patients, when it is less likely that reflux is present but it is still desirable to ensure that reflux is not occurring, radionuclide cystography is performed. If reflux is present, then a decision is made on an individual basis as to whether additional characterization by voiding cystourethrography is needed. Radionuclide cystography is also used for family screening, for periodic followup of reflux being managed nonoperatively and to ensure that reflux has been eliminated after antireflux surgery.

Child↗
PubMed1991

Urinary tract calculi that form on surgical staples: a characteristic radiologic appearance.

An autostapler is frequently used when bowel is interposed in the urinary tract during reconstructive urologic surgery in children. Usually the metallic staples are buried beneath the intestinal mucosa. However, if a portion of a staple is unintentionally left exposed or becomes exposed through migration and is then bathed by urine, it can become the nidus for formation of a calculus. The radiologic studies of 30 patients having surgery of this type in our hospital from 1980 to 1990 were reviewed prospectively, and stones were found to have developed on staples in eight patients. None of the patients had metabolic abnormalities. The stones were easily visible on plain radiographs because they were calcified. They formed in the lumen of the bladder or the bowel segment on the exposed portion of the staple. Thus, the staple was eccentric in the calculus and not central, as is usually the case with a stone forming on a foreign body. This experience suggests that stones forming on surgical staples during reconstructive urologic surgery have a characteristic radiologic appearance that may aid in their identification.

Adult↗
PubMed1991

Perforation of the augmented urinary bladder in nine children and adolescents: importance of cystography.

Augmentation of the urinary bladder is a popular surgical procedure for increasing the capacity and lowering the intraluminal pressure in patients whose bladder is small, noncompliant, or has high pressure. Among 250 augmentations performed at our hospital, nine patients have had 16 episodes of postoperative extravasation of urine from their augmented bladder. Thirteen episodes were studied by fluoroscopically monitored contrast cystography, which was diagnostic in 12. One patient's perforation was noted during an unrelated operation and the other two died of peritonitis before cystography could be performed. Four episodes occurred early, within 3 weeks of surgery. All were at a surgical anastomosis and presumably represented incomplete healing. Each patient with an early episode of extravasation had a perforation later. Nine perforations occurred from 1.0 to 6.5 months after the augmentation. Of these, three occurred at an anastomosis and four occurred in the augmenting segment. The locations of two were never fully documented. Three perforations occurred late, from 2.5 to 6.0 years after surgery, and all were in the augmenting segment. Three of the nine patients died of complications associated with perforation. Perforation of the bladder is not rare and is a potentially fatal complication of augmentation. Whenever a patient who has undergone augmentation has signs or symptoms suggesting perforation, cystography can play a crucial role in diagnosis and should be performed without delay.

Adolescent↗
PubMed1990

Pitfalls in pediatric urinary sonography.

Our review of pediatric urinary tract ultrasonograms over a period of two and one-half years resulted in a catalog of pitfalls. Cases included normal scans mistaken for abnormal and vice versa. These erroneous diagnoses stemmed from the inappropriate selection of the primary imaging test, improper timing of the ultrasonogram, errors of commission or omission in performance of the scans, and improper interpretation of the findings. For ease of reference, the pitfalls are grouped under bladder, ureters, and kidney with emphasis on the first two which are common sources of error.

Child↗
PubMed1990

Descent of the bladder neck: a urographic finding in denervation of the urethral sphincter in children with myelodysplasia.

The urographic position of the neck of the bladder in relation to the pubic symphysis was correlated with lower motor neuron (LMN) denervation of the urethral sphincter as detected with electromyography in 65 infants and children with myelodysplasia. Descent (prolapse) of the bladder (bladder neck below the upper margin of the pubic symphysis) was present in 30 (46.2%) patients. Prolapse was both more frequent and tended to be more severe in girls. Complete LMN denervation of the urethral sphincter was present in 25 (83.3%) of the 30 patients with prolapse and in only four (11.4%) of 35 with a normally positioned bladder. Conversely, 25 (86.2%) of the 29 patients with complete LMN denervation of the sphincter had prolapse as compared with only five (13.9%) of 36 patients with partial or no LMN denervation of the sphincter. Although not as precise as urodynamic testing, significant descent of the bladder neck is a reliable urographic finding of complete LMN denervation of the external urethral sphincter in infants and children with myelodysplasia.

Child↗
PubMed1990

The cloacal malformation: radiologic findings and imaging recommendations.

The imaging studies and records of 65 patients with the cloacal malformation seen from 1969 to 1989 were reviewed. The malformations were described according to cloacal configuration (urethral, vaginal), type of urinary-cloacal communication (urethral, vesical), and level of rectal communication (vaginal, cloacal, vesical, other). Lower urinary tract abnormalities were frequent (reflux, ureteral ectopia, bladder diverticula, bladder duplication, urachal remnants, urethral duplication), as were genital abnormalities (uterine duplication, vaginal duplication, uterine atresia, vaginal atresia), abnormalities of the bony pelvis (partial sacral agenesis, pubic diastasis), and renal abnormalities (agenesis, obstruction, horseshoe kidney). Contrast material studies of the cloaca and the distal limb of the colostomy with fluoroscopy in various projections were essential for diagnosis. Voiding cystourethrography was important for detecting vesicoureteric reflux. Sonography was of limited value for evaluation of the malformation but was valuable for imaging the kidneys. MR imaging revealed that spinal cord abnormalities cannot be predicted based on the appearance of the lumbosacral spine and are more common than previously thought.

Abnormalities, Multiple↗
PubMed1990

Importance of prenatal detection of hydronephrosis of the upper pole.

To determine the impact of prenatal detection on neonates with hydronephrosis of the upper pole of a duplex collecting system, we reviewed 40 such cases seen between June 1982 and April 1989. This six-per-year rate contrasts with fewer than one case per year that was seen at our hospital from 1947 to 1977. Nineteen patients had an ectopic ureterocele, and 21 had an ectopic ureter without a ureterocele. Thirty-three (83%) were girls. Thirty-three cases were discovered because of abnormal findings on a prenatal sonogram, and 20 of those infants were asymptomatic. In the 33 patients whose prenatal sonographic findings were abnormal, the sonogram was diagnostically precise for hydronephrosis of the upper pole of a duplex collecting system in only 39%. This imprecision did not adversely affect management or outcome. Postnatal sonography modified the prenatal diagnosis in 75% of these 33 patients. Voiding cystourethrography was the most sensitive and precise imaging technique for detecting both ureterocele and reflux. Lower pole reflux was almost twice as common when an ectopic ureterocele was present (63%) than when one was not (33%). Prenatal sonographic detection of hydronephrosis of the upper pole of a duplex collecting system decreased the proportion of neonates presenting with urinary tract infection and urosepsis because of prophylactic antibiotics initiated at birth and continued until surgical correction. Precise prenatal diagnosis was not needed for effective surgical treatment.

Humans↗
PubMed1990

The unsuspected double collecting system on imaging studies and at cystoscopy.

Five children (three girls and two boys) who had a duplex collecting system with an ectopic ureter or a ureterocele that was not detected with either imaging or cystoscopy were seen during a 10-year period. Four had urinary tract infection. The fifth was noted to have hydronephrosis when CT scanning of the abdomen was done for trauma. In each case, voiding cystourethrography showed reflux into what was thought to be a single (nonduplex) collecting system, but was found during surgery to be the lower pole of a duplex system. Excretory urography in four patients, sonography in two, and CT scanning in one did not show signs of duplication on the affected side. In each case cystoscopy failed to show a duplex system on the affected side. The diagnosis of duplication of the collecting system with ectopic ureter or ureterocele was made in each case only when the bladder was opened to reimplant the ureter. Direct opacification of the previously unsuspected upper pole ureter in each case showed it to be bind-ending and terminating at the level of the kidney. Radiologists and surgeons should be aware that duplex systems may not always be visible on urography and sonography.

Abnormalities, Multiple↗
PubMed1989

Urosepsis in infants with vesicoureteral reflux masquerading as the salt-losing type of congenital adrenal hyperplasia.

Three male infants with vomiting, dehydration, hyponatremia, hyperkalemia and metabolic acidosis were found to have vesicoureteral reflux (VUR) and urinary tract infection. Two were initially thought to have the salt-losing form of congenital adrenal hyperplasia. Although prompt diagnosis of this potentially fatal condition is critical, its mimicry by urosepsis in infants with VUR is actually more common. Infection probably causes unresponsiveness of the distal renal tubules to aldosterone.

Adrenal Hyperplasia, Congenital↗
PubMed1989

Congenital midureteral obstruction.

Congenital midureteral obstruction, caused either by a ureteral valve or stricture, is an exceedingly rare entity. When encountered, it is generally misdiagnosed as either primary megaureter or ureteropelvic junction obstruction, leading to a less than optimal surgical approach. Seven children with midureteral obstruction were seen over the past 17 years. Two of the patients presented with hydronephrosis on prenatal ultrasonography, and five with urinary tract infection. In only three was the diagnosis suspected on intravenous urography and voiding cystourethrography alone. Five of the seven cases had either antegrade or retrograde pyelography, prior to or at the time of their operative procedure, and in four of these a correct diagnosis was made. Notably, in five of the seven cases, recognition of the midureteral lesion prior to the surgical incision allowed the approach to be modified and a more appropriate technique (ureteroureterostomy) to be performed. The etiology of midureteral valve and stricture has been attributed to improper recanalization, insufficient vascular supply, or persistence of ureteral folds. Three of our patients had contralateral renal dysgenesis, suggesting an underlying ureteral bud abnormality.

Child↗
PubMed1989

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↗