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Biomedical subjects

R L Lebowitz

Publications and source records attributed to R L Lebowitz.

At least 37 records · Page 2Linked to original sources

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

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

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

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

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

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

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

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

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

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