Complete duplication of the bladder and urethra in the coronal plane: case report.
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Child, Preschool↗
Biomedical subjects
M Maizels
Publications and source records attributed to M Maizels.
TGF-beta mRNA expression in the renal pelvis after experimental and clinical ureteropelvic junction obstruction.
PURPOSE: The renal parenchymal expression of transforming growth factor-beta (TGF-beta) is increased in experimental obstructive uropathy. To better understand the pathophysiology of hydronephrosis, we pursued this observation by determining if the expression of TGF-beta is also increased in the obstructed renal pelvis. MATERIALS AND METHODS: The expression of TGF-beta mRNA was evaluated in experimental and clinical ureteropelvic junction obstruction by reverse transcriptase polymerase chain reaction (RT-PCR). Southern blot analysis with labeled human cDNA probes for TGF-beta was then done to verify the results. RESULTS: Experimentally, pelves subjected to ureteral constriction showed significantly higher TGF-beta mRNA expression than normals. After reversal of obstruction, the expression of TGF-beta remained significantly higher than normals but was not different from pelves with ongoing obstruction. Clinically, there was a significantly higher level of TGF-beta mRNA expression in obstructed pelves than in nonobstructed ureters. High levels of TGF-beta mRNA expression correlated significantly with good clinical outcome, good renal function, muscle hypertrophy and acute onset of obstruction. CONCLUSIONS: There is increased TGF-beta mRNA expression in the renal pelvis following clinical and experimental ureteropelvic junction obstruction. These data implicate TGF-beta in the adaptive molecular responses that increase muscle and collagen elaboration seen in hydronephrosis.
Animals↗
Outcome of nonspecific hydronephrosis in the infant: a report from the Registry of the Society for Fetal Urology.
Since 1988 the Society for Fetal Urology has worked to evaluate if there is consensus on management of infants with nonspecific hydronephrosis. Initially, multicenter agreement on the criteria to grade hydronephrosis and method of diuretic renography were developed to promote similarities in how infant kidneys with nonspecific hydronephrosis were profiled for grade (0 to 4), per cent differential function by diuretic renography and drainage response by diuretic renography (obstructed, not obstructed or indeterminate). Between 1989 and 1992 a total of 33 pediatric urologists from 21 cities registered 464 cases (582 kidneys) of hydronephrosis. Of the cases 275 (59%) were managed by observation and 189 (41%) were treated surgically. The operated kidneys showed profiles (hydronephrosis grade 3 or greater and diuretic renography obstructed) that were significantly different from the profiles of observed kidneys (hydronephrosis grade 2 or less and diuretic renography no obstruction) (p < 0.001 each). Six months postoperatively the mean grade of hydronephrosis (1.8) and diuretic renography diagnosis (no obstruction) were significantly better than they were preoperatively (p < 0.001 each). In addition, postoperatively the mean grade of hydronephrosis, diuretic renography diagnosis and per cent differential function were similar to age matched observed kidneys. We conclude that when radiographic tests are done similarly, there is consensus in the management of infant hydronephrosis by surgery or observation.
Databases, Factual↗
Ultrasound grading of hydronephrosis: introduction to the system used by the Society for Fetal Urology.
The Society for Fetal Urology (SFU) was founded in 1988 to study the postnatal evolution of prenatally detected anomalies of the urinary tract by following those neonates whose prenatal studies have brought them to medical attention while asymptomatic. The SFU has attempted to standardize methods of performing and grading the ultrasound and radionuclide examinations in this population. A system to grade upper tract dilatation or hydronephrosis (HN) imaged by ultrasound has been developed and is being used by SFU members in 36 institutions. The appearance of the calices, renal pelvis and renal parenchyma are key in determining the grade of HN and are illustrated in this article.
Female↗
Use of kidney internal splint/stent (KISS) catheter in urinary diversion after pyeloplasty.
We report on the use of a new catheter, the kidney internal splint/stent (KISS), to facilitate renal urine drainage following pyeloplasty. The catheter combines the desirable qualities of nephrostomy tube diversion, anastomotic stent, and trocar placement in a single tube. The special construction of its lumen diminishes the likelihood of obstructed drainage. Our experience using the KISS catheter with 31 patients undergoing pyeloplasty shows it provides effective internal and external urinary diversion.
Adolescent↗
Does early pyeloplasty really avert loss of renal function? A retrospective review.
We reviewed 75 cases of isolated, unilateral pediatric ureteropelvic junction obstruction and 167 diuretic radionuclide renograms performed during the last 8 years. Differential function of the affected kidney was calculated using scintillation count data at 1 and 3 minutes, and the area under the renogram curve between 1 and 3 minutes. There was no significant difference among the 3 measures of per cent differential function for a given patient. Per cent differential function on the first renogram preoperatively neither declined as age at presentation advanced nor did it vary according to the clinical presentation. Similarly, the changes in postoperative per cent differential function were unaffected by the age at initial presentation, manner of presentation, occurrence of postoperative complications or the surgeon. These data do not support the concept that pyeloplasty for the isolated, unilateral ureteropelvic junction obstruction should be performed early to avert loss of renal function.
Adolescent↗
Response of the newborn ureteropelvic junction complex to induced and later reversed partial ureteral obstruction in the rabbit model.
The clinical controversy regarding the timing of surgery for asymptomatic newborns with obstructed hydronephrosis was addressed using a model of reversible partial ureteral obstruction in the newborn rabbit. The histomorphometric changes in the ureteropelvic junction complex (for example, pelvis, ureteropelvic junction and upper ureter) and kidney in 44 normal cases were determined and compared with the effects of 47 cases of ongoing partial obstruction and timed reversal of partial obstruction at 1 week in 9 cases, at 2 weeks in 10 or at 4 weeks in 10 (end of the study at age 8 weeks). After partial obstruction hydronephrosis appeared by 1 week postoperatively. There were progressive increases in the thickness of the lamina muscularis and mass index of smooth muscle and collagen (all p < 0.001). However, since the per cent surface area of smooth muscle did not change significantly in comparison to normal, there was disproportionately more collagen. For reversals at 1 week the muscle and collagen in the lamina muscularis were not significantly different from normal. For reversals at 2 weeks the mass index of collagen was greater than normal (p < 0.05) and reversal at 1 week (p < 0.05). For reversals at 4 weeks the lamina muscularis was thicker, and the mass index of collagen and muscle was greater than the earlier reversal groups and normal (all p < 0.05). In conclusion, partial ureteral obstruction causes progressive thickening of the lamina muscularis by collagen and muscle with a disproportionately greater increase in collagen than muscle. The earlier the obstruction can be reversed, the more normal is the ureteropelvic junction complex histology. The functional significance of these changes needs to be determined.
Animals↗
Management of the undescended testis.
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Cryptorchidism↗
Microanatomy and morphometry of the hydronephrotic "obstructed" renal pelvis in asymptomatic infants.
There has been limited histological study of the obstructed ureteropelvic junction in patients less than 1 year old. We present our prospective studies on the histomorphometry of the ureteropelvic junction complexes of 35 infants, of whom 23 underwent pyeloplasty for obstruction and 12 were age matched autopsy normals. Qualitatively, the major abnormalities of the pelvic microanatomy in the hydronephrotic obstructed kidneys included a lamina muscularis that was significantly thicker than normal and the presence of collagen fibers between muscle fascicles. Additionally, variable amounts of elastin were present in the adventitia and lamina muscularis. At the ureteropelvic junction the abnormalities were an increase in the number of inner longitudinal muscle bundles, collagen between muscle bundles (p less than 0.016) and elastin in the adventitia. Quantitatively, for the pelvis the lamina muscularis was significantly thicker in 18 obstructed kidneys compared to 7 controls (1,075 +/- 79 mu. versus 420 +/- 63 mu., mean +/- standard error of mean, p less than 0.001). The percentage area density of smooth muscle in the obstructed versus normals was increased (45.1% versus 35.2%, p less than 0.039). The percentage area density of collagen in the obstructed specimens versus normal showed an upward trend (38.6% versus 27.6%), which was not significant. In conclusion, the obstructed ureteropelvic junction complexes of kidneys in asymptomatic infants show significant qualitative and quantitative differences from normal.
Humans↗
Grading nephroureteral dilatation detected in the first year of life: correlation with obstruction.
To understand better the significance of pediatric idiopathic nephroureteral dilatation the renal ultrasound images of patients less than 1 year old with hydronephrosis or hydroureteronephrosis were graded and compared to the radiological diagnosis of obstruction as determined by diuresis renography and/or urography. The study included 73 boys and 30 girls with hydronephrosis (76 patients) or hydroureteronephrosis (27). For hydronephrosis obstruction was diagnosed in 56 children (74%) and involved 61 of 97 kidneys (63%). For obstructed kidneys the mean grade of hydronephrosis (3.4 +/- 0.7 standard deviation) was statistically different from that of nonobstructed kidneys (1.6 +/- 0.8 standard deviation) (p less than 0.05). When the value to predict obstruction was set at grade 3 hydronephrosis or greater there was an 88% sensitivity and 95% specificity. For hydroureteronephrosis obstruction was diagnosed in 15 of 27 children (56%) and involved 17 of 34 kidneys (50%). The degree of dilatation was weighted as a score to assess the grades of hydronephrosis and ureteral dilatation, namely hydroureteronephrosis score equals grade of hydronephrosis plus grade of ureteral dilatation. In obstructed megaureters the mean hydroureteronephrosis score (5.8 +/- 1.0) was statistically different from that for nonobstructed megaureters (mean hydroureteronephrosis score 2.7 +/- 1.9) (p less than 0.001). When the value to predict obstruction was set at hydroureteronephrosis score of 5 or greater there was a 94% sensitivity and 80% specificity. Although ultrasound examination alone cannot be used to diagnose urinary obstruction, the radiological diagnosis of obstruction is linked with the grade of hydronephrosis or score of hydroureteronephrosis.
Age Factors↗
The "well tempered" diuretic renogram: a standard method to examine the asymptomatic neonate with hydronephrosis or hydroureteronephrosis. A report from combined meetings of The Society for Fetal Urology and members of The Pediatric Nuclear Medicine Council--The Society of Nuclear Medicine.
Perinatal hydronephrosis (HN) and hydroureteronephrosis (HUN) are recognized more frequently as the routine use of prenatal ultrasonography increases. The decision-making process for those instances of urinary tract dilatation that require surgical correction and those that do not is based in part on the findings of diuresis renography. The methodology for performing this test has differed among nuclear medicine practitioners and the surgical findings are occasionally discrepant from the diuretic renogram interpretation. Consequently, the Society of Fetal Urology (SFU) and the Pediatric Nuclear Medicine Council (PNMC) of the Society of Nuclear Medicine met to develop by consensus a more uniform methodology. A standard method has been agreed upon for the following facets of diuretic renography: patient preparation (hydration and bladder catheterization), diuresis renography technique (radiopharmaceutical used, patient position during examination, data acquisition parameters, diuretic pharmaceutical and dosage, time of injection and regions of interest to monitor diuretic effect), and data analysis (percent differential renal function, curve pattern analysis and methods of measuring diuretic response). Pooled diuresis renogram data are being collected for analysis for correlation with surgical results and clinical outcomes to determine the most appropriate information to be derived from the diuretic renogram in neonates with HN and HUN.
Data Interpretation, Statistical↗
Insertion of testicular prosthesis: use of vaginal speculum.
We have used a vaginal speculum to insert a testicular prosthesis through the inguinal approach over the past four years. We have found this technique to be easily performed and reproducible in allowing the testicular prosthesis to be placed in the normal dependent position in the scrotum.
Adolescent↗
Role of in-office ultrasonography in screening infants and children for urinary obstruction.
With the availability of machines suitable for the office, we studied whether in-office ultrasonography could assist in the management of children with known or suspected hydronephrosis. Of 509 children examined, 81 (16 per cent) had hydronephrosis. In 56 (70 per cent) of these children, ultrasonography was helpful in expediting the diagnosis (9 cases), clarifying the etiology (16 cases), evaluating the condition postoperatively (26 cases), and screening (5 cases). Three incorrect ultrasound diagnoses were encountered. The authors believe that ultrasound is the best initial imaging method for the urinary tract and have shown that it is practical and effective in an office setting.
Child↗
Surgical correction of anterior urethral diverticula after hypospadias repair in children.
We present a new surgical technique to correct acquired anterior urethral diverticula after hypospadias repair. The correction involves a degloving circumferential skin incision, excision of the diverticulum, and closure of the urethra incorporating overlapping suture lines.
Child, Preschool↗
Ultrasonography and diagnosis of pediatric genitourinary rhabdomyosarcoma.
Rhabdomyosarcoma is the most common tumor of the lower genitourinary tract in children during their first two decades of life. Four patients with genitourinary rhabdomyosarcoma are presented, with ultrasonographic and radiographic findings. The utility of ultrasound in the diagnosis of this pediatric tumor is emphasized.
Child↗
Silicone foam dressing for penis after reconstructive pediatric surgery.
Although silicone foam has been used abroad as an effective means to dress the penis after hypospadias surgery, its use has not been widespread in the United States. We have modified the method to apply the foam in order to facilitate its use. We used this method to dress the penis with silicone foam in 50 boys after reconstructive surgery. The dressing appeared to be effective in restricting edema and hematoma formation. Also, the dressing stabilized the indwelling urethral catheter thereby preventing disruption of the glansplasty. The urethrocutaneous fistula rate (10%) was not reduced by use of the foam. The dressings uncommonly fell off prematurely. The boys appeared to experience little discomfort while the foam was in place and during its removal.
Bandages↗
Surgery for duplex kidneys with ectopic ureters: ipsilateral ureteroureterostomy versus polar nephrectomy.
Conventional surgery for the ectopic ureter stresses polar nephrectomy, while preserving a functioning upper pole by ipsilateral ureteroureterostomy is performed less commonly. During the last 15 years we operated on 35 children for ectopic ureter. High ipsilateral ureteroureterostomy (15 patients) was performed when the upper pole cortex appeared to be smooth and pink, and the anastomosis was surgically feasible. Upper pole nephrectomy and upper ureterectomy (21 patients) were performed when the involved segment appeared grossly to be pale, cystic or otherwise abnormal. One low ipsilateral ureteroureterostomy was performed concomitant with contralateral ureteral reimplantation. Complications after ipsilateral ureteroureterostomy and partial nephrectomy were similar. Histological evidence of dysplasia of the polar nephrectomy specimens was focal in 7 patients (33 per cent), marked in 2 (10 per cent) and not detected in 12 (57 per cent). Ipsilateral ureteroureterostomy is an appropriate means to manage the ectopic ureter in selected cases because dysplasia in these upper pole renal units seldom is significant, and because ipsilateral ureteroureterostomy and polar nephrectomy have similar postoperative morbidity rates.
Child↗
Urinary obstruction reduces glomerulogenesis in the developing kidney: a model in the rabbit.
To study the effect of unilateral ureteral obstruction upon the development of the kidney a fetal rabbit model was developed. A total of 27 rabbits underwent ureteral ligation in utero (24 days after conception) and 34 underwent ureteral ligation at term (30 days after conception). Two rabbits undergoing in utero ureteral ligation underwent decompression at term. Fetal development was evaluated by glomerular counts of mid sagittal sections of the kidney and compared to that of 67 normal rabbits, 43 littermates of rabbits undergoing surgery, 12 rabbits with missed ligation of the ureter and 4 whose ureters were ligated after the period of nephrogenesis had ended (57 days after conception). In the normal rabbit term occurred at 31 days after conception but nephrogenesis continued until 48 days when the cortical glomerular count reached approximately 650. Ligation of the ureter at 24 days led to a rapid decrease in cortical glomerular counts in the obstructed kidney but glomeruli developing within the nephrogenic cap were more resistant to the effects of the obstruction. Glomerular counts in the nonobstructed kidney were similar to those of littermates. Ligation of the ureter at 30 days produced similar findings. All operated fetuses and their littermates showed glomerular counts less than that of normal animals of the same age. In the 2 fetuses who underwent ureteral ligation at 24 days after conception and decompression at 30 days after conception sacrifice at 42 days after conception revealed that glomerular counts that had been reduced by 95 per cent by the obstruction showed 80 per cent recovery after decompression. It appears that renal development can be quantified by glomerular counts in the rabbit. Obstruction during fetal development reduces these counts while in a limited sample decompression of the obstructed kidney partially restores them. This model appears to be suitable for the study of the effects of fetal surgery upon renal function.
Animals↗