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Biomedical subjects

M Maizels

Publications and source records attributed to M Maizels.

At least 73 records · Page 4Linked to original sources
PubMed1984

The management of children with vesicoureteral reflux and ureteropelvic junction obstruction.

We reviewed our management of children with vesicoureteral reflux and ureteropelvic junction obstruction in the same renal unit. Of the children who underwent pyeloplasty for ureteropelvic junction obstruction 9 per cent also had vesicoureteral reflux. These children were almost exclusively boys. Ureteropelvic junction obstruction was caused mostly by a stricture or fixed kinks of the upper ureter. Vesicoureteral reflux was primarily grade IV and was associated with abnormal morphology of the ureteral orifice. Pyeloplasty was the initial surgical correction and ureteral reimplantation was performed expectantly.

Child↗
PubMed1983

Surgical correction of the failed orchiopexy.

The reasons for failure of orchiopexy were investigated by reviewing the records of 350 boys with undescended testis. There were 36 boys (10 per cent) who had experienced failure of an initial surgical procedure. We found that the standard surgical techniques of local inguinal dissection, high ligation of a patent processus vaginalis, extensive retroperitoneal mobilization of the spermatic vessels and vas deferens, and/or creation of a dartos pouch were sufficient to correct these failures. Retroperitoneal dissections were required to correct the undescended testes in 58 per cent of the boys. Only 37 per cent of the boys could be treated satisfactorily by localized inguinal dissection. It appears that standard surgical techniques, especially aggressive retroperitoneal dissection, are adequate to correct even troublesome cases of undescended testis.

Adolescent↗
PubMed1983

Bilateral cecoureteroceles causing urinary retention in the newborn.

The cecoureterocele differs from the usual ectopic ureterocele because it extends outside the bladder and may obstruct the urethra. The differentiation requires careful examination of the urethra by a voiding cystourethrogram and cystoscopy. We describe the management of a girl with bilateral cecoureteroceles who presented as a newborn with urinary retention and sepsis. Surgical correction of the cecoureterocele may differ from that required for the usual ectopic ureterocele.

Escherichia coli Infections↗
PubMed1983

The vesical sphincter electromyogram in children with normal and abnormal voiding patterns.

Recording the vesical sphincter electromyogram clarifies abnormal patterns of voiding in children. Since the electromyogram patterns in children with normal voiding patterns have not yet been evaluated, we recorded the sphincter electromyograms during voiding of 39 children with normal voiding patterns. These normal electromyograms were compared to those recorded in 86 children with abnormal voiding patterns. Each of the 39 children with a normal voiding pattern demonstrated synergy of the vesical sphincter during voiding. Of the 86 children with an abnormal voiding pattern 69 per cent demonstrated synergy and 31 per cent demonstrated dyssynergia of the vesical sphincter during voiding. Of the children with dyssynergia 89 per cent were girls and only 11 per cent were boys. Sphincter dyssynergia was demonstrated only by children with an abnormal pattern of voiding and those with a history of a normal pattern of voiding demonstrated only sphincter synergy (p less than 0.005). The electromyographic diagnoses of vesical sphincter synergy and dyssynergia obtained by surface electrode recordings correlated with the clinical voiding patterns of the children.

Adolescent↗
PubMed1983

Cowper's syringocele: a classification of dilatations of Cowper's gland duct based upon clinical characteristics of 8 boys.

Lesions of Cowper's gland duct assume various appearances. A system to classify each of these appearances is offered to diagnose these lesions more precisely. The urethrographic and endoscopic characteristics of dilated Cowper's gland ducts noted in 8 boys are grouped as a simple classification. The dilated Cowper's duct is referred to as a syringocele (Greek syringo--tube plus cele--swelling). There are 4 groups of Cowper's syringoceles: 1) simple syringocele--a minimally dilated duct, 2) perforate syringocele--a bulbous duct that drains into the urethra via a patulous ostium and appears as a diverticulum, 3) imperforate syringocele--a bulbous duct that resembles a submucosal cyst and appears as a radiolucent mass, and 4) ruptured syringocele--the fragile membrane that remains in the urethra after a dilated duct ruptures. Marsupialization of the syringoceles cured urine infection and hematuria but voiding symptoms may persist.

Adolescent↗
PubMed1983

Bladder capacity (ounces) equals age (years) plus 2 predicts normal bladder capacity and aids in diagnosis of abnormal voiding patterns.

Standardization of the bladder capacities of children will improve the precision of urodynamic evaluation. In an attempt to develop a practical guide to predict the normal bladder capacity during childhood the bladder capacities of 132 children without a clinically abnormal pattern of voiding were measured. When the bladder capacities are correlated by age the following linear relationship exists: normal bladder capacity (ounces) equals age (years) plus 2. The bladder capacities of 68 children with primary enuresis, frequency or infrequent voiding were then measured. Children with clinically infrequent voiding demonstrated large bladder capacities and those with frequency or enuresis demonstrated small bladder capacities compared to normal children. The formula appears to be a useful guide to predict normal bladder capacity by age and also to aid in the diagnosis of abnormal voiding patterns.

Adolescent↗
PubMed1983

The use of lower ipsilateral ureteroureterostomy to treat vesicoureteral reflux or obstruction in children with duplex ureters.

During the last 4 years lower ipsilateral ureteroureterostomy was performed to treat vesicoureteral reflux and/or obstruction in 11 children with 13 completely duplicated systems. There was reflux only to the lower segment in 11 systems, obstruction only to the upper segment in 1 and reflux with obstruction in 1 system. The procedure is technically easier than ureteroneocystotomy, avoids cystotomy and permits a brief postoperative hospitalization. The postoperative excretory urogram demonstrated improved or stable hydronephrosis in all patients. Vesicoureteral reflux persisted in 1 system associated with a golf hole orifice. Caution should be exercised when children with reflux in duplex systems associated with a golf hole ureteral orifice are treated.

Adolescent↗
PubMed1982

The role of urinary obstruction in the genesis of renal dysplasia. A model in the chick embryo.

Although obstruction of urinary drainage is the current pathogenetic mechanism believed responsible for renal dysplasia, the results of experimental studies have not uniformly substantiated this impression. To help resolve this issue, we evaluated the effect of obstruction of the urinary drainage of the embryonic kidney upon the later development of the kidney. We developed a model which allowed us to ligate the ureter surgically of the chick embryo before and after the appearance of nephrons. Initially, the normal morphologic features of renal development were studied in 22 embryos at various stages of incubation and in 94 metanephric rudiments cultivated as chorioallantoic membrane (CAM) grafts. Then, the morphologic features of renal development were studied in 151 metanephric rudiments subjected to surgical ligation of the primitive ureter and then cultivated as CAM grafts. The ligations were performed with 9-0 silk suture, aided by the operating microscope, and induced before and after the appearance of nephrons. Renal differentiation of the non-ligated rudiments cultivated as CAM grafts resembled that which appeared in situ. Renal differentiation of 87 per cent of nonligated rudiments which survived grafting displayed normal renal development and 13 per cent displayed mild hydronephrosis. Renal differentiation of 67 per cent of the ligated rudiments which survived grafting displayed hydronephrosis and 33 per cent displayed normal development. Dysplasia was never seen in any specimen. Obstruction of the ureter of the developing kidney caused only hydronephrosis in the chick model. It appears that renal dysplasia is not solely caused by simply mechanical obstruction to urinary drainage, even when the obstruction is imposed at early stages of renal development.

Animals↗
PubMed1980

Valves of the ureter as a cause of primary obstruction of the ureter: anatomic, embryologic and clinical aspects.

The causes of obstruction of the ureter at the ureteropelvic and ureterovesical junctions are still controversial. In this study portions of obstructed ureters were excised at operation or autopsy and the suspected sites of obstruction were examined anatomically, radiographically and histologically. A valvular mechanism caused obstruction in 15 of 27 specimens. The valve lay at the junction of the dilated and undilated segments of the ureter. The internal anatomy of this site was hidden from external view by the fascia overlying the ureter and was demonstrated by contrast ureterograms. The axes of the lumina of the dilated and undilated segments were eccentric and the walls of the ureter overlapped at the site of obstruction to form a common wall, which created a valve effect. The valve flaps were visualized radiographically as a filling defect. The valve obstructed antegrade but not retrograde flow. Anatomic dissection or serial sections of blocks of the valve zone demonstrated that either a single or a double flap caused obstruction. The valve was coapted against the opposite wall of the distal segment by the pressure generated in the dilated ureter during antegrade flow. The muscle of the unobstructed segment of ureter distal to the valve appeared normal histologically, whereas the muscle of the obstructed proximal segment was hypertrophic.

Child↗
PubMed1980

Decreased incidence of bacteriuria associated with periodic instillations of hydrogen peroxide into the urethral catheter drainage bag.

We determined the incidence and source of bacterial colonization of the bladder in 31 consecutive patients with acute spinal cord injury who required indwelling urethral catheterization. Patients were randomized to conventional drainage or to conventional drainage with a secondary sterile bag for periodic administration of saline or 3 per cent hydrogen peroxide. The hydrogen peroxide group maintained sterile bladder urine significantly longer than the conventional drainage group (p less than 0.05). Cultures suggested that the reservoir for bladder colonization was the bag in 5 of 12 patients (42 per cent) on conventional drainage. Instillation of hydrogen peroxide prevented bacterial contamination of the drainage bag before bladder bacteriuria (p less than 0.01) and also reduced drainage bag bacteriuria in patients with urinary infections (p less than 0.0005). The data indicate that bacterial contamination of the drainage bag is a frequent source of bladder bacteriuria that can be eliminated effectively by periodic instillation of hydrogen peroxide.

Adolescent↗
PubMed1979

Urodynamic biofeedback: a new approach to treat vesical sphincter dyssynergia.

Some children with vesical sphincter dyssynergia are refractory to conventional pharmacologic therapy. Three such patients were treated using a method of sphincter retraining, biofeedback. They observed the urinary sphincter electromyogram while voiding to appreciate visually the abnormality. Two children learned to suppress voluntarily the inappropriate sphincter contraction during voiding. This normalized the subsequent electromyographic recordings and offered subjective improvement in the voiding symptoms. Retraining the urethral sphincter dysfunction may be approached using biofeedback techniques in selected patients.

Adolescent↗
PubMed1979

Pediatric urodynamics: a clinical comparison of surface versus needle pelvic floor/external sphincter electromyography.

Urodynamic evaluations were done on 37 children to diagnose voiding pattern abnormalities and/or recurrent urinary infections. Each of 25 children had 2 sets of testing to judge a practical method of urodynamic evaluation. Bipolar anal skin electrodes were compared to bipolar perianal muscle needle electrodes as a means of monitoring the urethral sphincter/pelvic floow electromyographic activity. In addition, the urethral catheter was compared to the suprapubic catheter as a means of monitoring intravesical pressure. The results were similar and statistically significant (p less than 0.001). The remaining 12 children were evaluated based only on the results of bipolar anal skin electrodes and uroflowmetry. The results of both groups clearly demonstrated that surface perianal electrodes are practical, accurate and reliable for the diagnosis and treatment of children with voiding pattern abnormalities. We recommend the use of surface electrodes and a urethral catheter as techniques for the urodynamic evaluation of voiding pattern abnormalities of children without overt neuropathology or extensive urethral operation. Preoperative surface electromyography of the urinary sphincters may prove to be a useful screening test to detect occult dyssynergia in patients who have had failed ureteral reimplants.

Adolescent↗
PubMed1979

The cystometric nuclear cystogram.

Vesicoureteral reflux is a common clinical problem that we monitor by interval nuclear cystography. Of the children having nuclear cystograms 40% also have voiding abnormalities, including incontinence (damp pants), urgency and infrequent micturition. We have evaluated these symptoms by recording the intravesical pressure during the nuclear cystogram. This combined examination, the cystometric nuclear cystogram, has been done on 46 children. An abnormal cystometrogram was found in 61% of the children with a voiding abnormality and helped to establish a basis for successful therapy. The cystometric nuclear cystogram aids in the diagnosis and rational therapy of childhood voiding abnormalities. It is a practical method to obtain a cystometrogram in children with voiding abnormalities who are being evaluated for ureteral reflux and it has facilitated the management of childhood ureteral reflux.

Child↗
PubMed1979

The induction of urologic malformations. Understanding the relationship of renal ectopia and congenital scoliosis.

The normally straight caudal trunk of the 3-day-old chick embryo was surgically deflected, constricted, or pierced using fine steel instruments. The delayed effects of these injuries were evaluated anatomically by performing microdissections of the genitourinary systems of the chicks surviving these operations. Eighty-six of 181 survivors of 347 operations showed malformations. Renal ectopia appeared with scoliosis 10 times more often than it appeared by itself (P less than 0.01). Eighty-six chicks survived 102 control operations; only two had a urinary anomaly (P less than 0.01). The paring of renal ectopia with scoliosis may be attributable to an isolated spinal defect that precludes complete renal ascent, an injury to the anlages of both the spine and kidney, or a genetic abnormality that affects both anlages.

Abnormalities, Multiple↗