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Biomedical subjects

H M Snyder

Publications and source records attributed to H M Snyder.

At least 109 records · Page 6Linked to original sources
PubMed1989

Coexisting ureteropelvic junction obstruction and vesicoureteral reflux: diagnostic and therapeutic implications.

The coexistence of ureteropelvic junction obstruction and vesicoureteral reflux was seen in 17 (14 per cent) of 147 consecutive patients undergoing pyeloplasty. These patients were analyzed to determine the therapeutic implications of this association. They fell into 3 clinical groups: group 1--primary ureteropelvic junction obstruction, group 2--ureteropelvic junction obstruction secondary to high grade reflux and group 3--pseudo-ureteropelvic junction obstruction. There were 11 patients in group 1. These patients had incidental low grade reflux. Pyeloplasty should be the initial procedure with use of a nephrostomy tube or Foley catheter postoperatively. Vesicoureteral reflux resolved spontaneously with linear growth in approximately half of the cases. There were 4 patients in group 2. The obstructive uropathy should be treated initially, since primary ureteral reimplantation may provoke acute ureteropelvic junction decompensation. There were 2 patients in group 3. Pseudo-ureteropelvic junction obstruction is suggested when pelvic dilatation on the voiding cystourethrogram suggests obstruction but drainage films or antegrade studies document good drainage. The recognition of pseudo-ureteropelvic junction obstruction is important to avoid surgery on a ureteropelvic junction that is not obstructed. Primary correction of the reflux is appropriate. However, it must be recalled that a fixed kink may rarely develop later leading to true secondary ureteropelvic junction obstruction, which will require surgical correction. We recommend that a voiding cystourethrogram be part of the routine evaluation of children with suspected ureteropelvic junction obstruction.

Child↗
PubMed1989

Postnatal testicular maldevelopment in unilateral cryptorchidism.

Histomorphometric analysis of semi-thin sections was performed on testicular biopsies of 232 unilaterally cryptorchid testes and 195 of their contralateral descended partners. The results demonstrated a decreased number of germ cells detectable from the first year of life. There was delayed and defective transformation of gonocytes to Ad spermatogonia, which normally is complete at age 6 months, delayed or failed transformation of Ad spermatogonia to primary spermatocytes, which normally commences at age 3 years and decreased numbers of Leydig cells. These abnormalities were present in the unilaterally cryptorchid testes and their contralateral descended partners but they were more severe, of earlier onset and more progressive in the cryptorchid testes. These findings are compatible with the hypothesis that hypogonadotropic hypogonadism is the cause of the increased incidence of infertility seen in unilateral cryptorchidism.

Biopsy↗
PubMed1989

Cryptorchidism, orchiopexy and infertility: a critical long-term retrospective analysis.

We assessed the fertility of 40 patients who underwent orchiopexy between 1950 and 1960. Testicular biopsies also had been performed at operation, a practice exceptional for the era. Of 23 patients with unilateral undescended testes who attempted to have children 20 (87 per cent) were successful. In contrast, only 3 (33 per cent) of 9 patients with bilateral undescended testes fathered children. Over-all sperm counts in 16 patients were low but they were not predictive of paternity. Testicular biopsy specimens were reviewed and the fertility index was determined. In most cases a good correlation was found between histological status and paternity status.

Adult↗
PubMed1989

Changing concepts in management of primary obstructive megaureter.

The management of neonatal urinary tract dilatations represents one of the most challenging dilemmas in pediatric urology today. We have been confronted with 44 renal units in 35 neonates diagnosed as having primary obstructive megaureter during the last 6 years. Of these units 23 in 17 infants were diagnosed antenatally and 20 (87 per cent) have been managed without surgical intervention. Notably, 16 renal units were graded as moderate to severe megaureters by an excretory urogram. The decision to manage conservatively was based on the initial extraction of the 99mdiethylenetriaminepentaacetic acid renal scan (the extraction factor). This estimate of absolute renal function has been used to differentiate dilatations with obstructive implications for the renal parenchyma from those without. Significantly, expectant treatment has resulted in improvement of dilatation on sequential excretory urograms in 15 megaureters and none has shown a deterioration of function by renal scan. Similar diagnostic criterion also has resulted in conservative management for 12 of 21 additional neonatal megaureters seen during this period with symptoms or they were discovered serendipitously. Only 2 of these 12 megaureters required surgical correction. The neonatal primary megaureter appears in many cases to represent a different entity than those that commonly presented before the advent of antenatal and perinatal diagnosis.

Dilatation, Pathologic↗
PubMed1989

Hinging the urethral plate in hypospadias meatoplasty.

A technique is described for creation of a cosmetically normal, vertical slit-like urethral meatus in conjunction with common hypospadias reconstructions that preserve the urethral plate. The distal portion of the urethral plate is incised longitudinally in the midline. This incision allows the flat and rigid urethral plate to be folded or hinged during glans plasty, molding it into an anatomically correct vertical slit configuration. This modification has been applied successfully to a variety of meatal-based flap and onlay island flap urethroplasties with no increased morbidity and a significant improvement in meatal cosmetic results.

Epithelium↗
PubMed1989

Urological manifestations of the popliteal pterygium syndrome.

We report a case of the popliteal pterygium syndrome resulting in abnormalities of the external genitalia and testicular ectopia. Management included bilateral orchiopexy and complex genitoplasty. Pterygia represent errors in development that manifest as webs across joints and can result in anomalies of the external genitalia. The genitourinary aspects of the popliteal pterygium syndrome and their management are discussed.

Abnormalities, Multiple↗
PubMed1988

Protective factors in posterior urethral valves.

Patients with posterior urethral valves may present with or contract renal insufficiency. High intravesical pressure that is transmitted to the upper urinary tract in utero is a likely contributing cause. We have identified 3 anatomical associations with posterior urethral valves that provide a pressure "pop-off" mechanism resulting in preservation of better renal function: 1) the syndrome of posterior urethral valves, unilateral vesicoureteral reflux and renal dysplasia; 2) large congenital type bladder diverticula and 3) urinary extravasation with or without urinary ascites. Followup of 71 boys with posterior urethral valves was sufficient to permit long-term analysis. Serum creatinine was used as an index of renal function and prognosis. Of the 71 boys 20 (28 per cent) had 1 of the 3 protective mechanisms. Only 1 child (5 per cent) had a serum creatinine greater than 1.0 mg. per cent. Of the remaining 51 boys without a "pop-off" mechanism 20 (39 per cent) had serum creatinine greater than 1.0 mg. per cent and 7 had already progressed to renal dialysis and/or transplantation. The difference in serum creatinine was statistically significant (p less than 0.01). Thus, the syndrome of posterior urethral valves, unilateral vesicoureteral reflux and renal dysplasia; large congenital bladder diverticula and urinary extravasation can serve as a "pop-off" mechanism to buffer high pressures in the urinary tract and to lead to the preservation of better renal function in boys with posterior urethral valves.

Child, Preschool↗
PubMed1988

Perforation of the augmented bladder in patients undergoing clean intermittent catheterization.

During urological reconstructive surgery small or large bowel is used to increase bladder capacity or to create a urinary reservoir. In most patients clean intermittent catheterization is necessary for urinary drainage. We report on 4 patients with a sigmoid cystoplasty who perform clean intermittent catheterization and who have experienced a serious long-term complication, urinary reservoir perforation, which was fatal in 1. Two were adolescent girls with myelodysplasia and 2 were prepubertal boys with bladder exstrophy. One patient experienced 2 separate reservoir perforations. Rupture occurred 15 to 48 months (mean 30.2 months) after reconstruction. Diagnosis was made by a static cystogram, which demonstrated extravasation in 2 of 4 patients, and ultrasound. In 2 patients the cystogram was normal. Management included intravenous antibiotics and open abscess drainage in all patients. In patients who have undergone augmentation cystoplasty or continent diversion and in whom abdominal pain and distension develop reservoir perforation should be considered in the differential diagnosis.

Adolescent↗
PubMed1988

Simple cysts of the testis in children: preoperative diagnosis by ultrasound and excision with testicular preservation.

We report on 2 children with simple cysts of the testis who were treated with excision and testicular preservation. To our knowledge both cases represent the first report of conservative surgery for these lesions in children. In 1 case the diagnosis of a simple intratesticular cyst was made by ultrasound. This patient was followed conservatively until enlargement resulted in excision of the cyst with preservation of the gonad. In the other case the diagnosis was made intraoperatively and simple excision of the lesion with testicular sparing was performed. High resolution real-time ultrasound should be performed routinely for all suspected testicular masses in children. Benign testicular tumors are more common than in adults and ultrasound may permit identification of lesions that can be excised locally with testicular preservation. Should the diagnosis of a simple, small intratesticular cyst be made by ultrasound regular followup may be appropriate. Should enlargement occur surgical excision can be done with the possibility of gonadal preservation.

Cysts↗
PubMed1988

Surgical management of urinary incontinence in children.

The field of continent reconstruction continues to expand rapidly, as new innovations are introduced by imaginative surgeons. Today, review of previous experience and knowledge of physiology permit creation of solutions to previously insoluble problems. It must be stressed that long-term results are not available for many of these procedures, but with careful follow-up, the outlook is promising.

Cecum↗
PubMed1987

Intervention for fetal obstructive uropathy: has it been effective?

The best management of fetal hydronephrosis is controversial. Despite the lack of experimental evidence that prenatal drainage of the obstructed urinary tract substantially improves ultimate renal function, various forms of percutaneous intervention on the fetal bladder and kidney have been used. To evaluate the efficacy of intervention for suspected fetal obstructive uropathy, all published reports of drainage of the fetal urinary tract up to December, 1985, were reviewed. In the 57 reported cases, the most common type of intervention was placement of a vesicoamniotic shunt (37%). Complications occurred in 25 cases (44%), including inadequate shunt drainage or migration (19%), onset of premature labour within 48 h (12%), urinary ascites (7%), and chorioamnionitis (5%). Of 28 fetuses with associated oligohydramnios, only 6 (21%) survived. 2 of these survivors had vesicoamniotic shunts, 2 single or multiple bladder aspirations, 1 an external renal drainage catheter, and 1 in-utero vesicostomy. Because of the high complication rate and lack of evidence of improved survival from in-utero drainage procedures, a prospective, randomised trial is needed to compare survival with and without vesicoamniotic shunt placement.

Amnion↗
PubMed1987

Germ cell counts in semithin sections of biopsies of 115 unilaterally cryptorchid testes. The experience from the Children's Hospital of Philadelphia.

One hundred and fifteen biopsies from unilateral cryptorchid prepubertal patients were embedded in Epon. Semithin sections were examined by light microscope and the germ cell count per tubule was calculated. The mean number of germ cells was normal from birth to 12 months of age and dropped below the lower limits of normal between 1 and 2 years. Germ cell counts rose considerably during the 18-months observation period with the highest counts occurring in the last 6 months. Variability in the clinical diagnosis of cryptorchidism or inherent heterogeneity in the testicular histology of cryptorchidism are possible explanations.

Biopsy↗
PubMed1987

Association of congenital megacalycosis and ipsilateral segmental megaureter.

Four cases of congenital megacalycosis associated with ipsilateral segmental megaureter in children are presented. This association has not been emphasized, although review of the English and French literature revealed eight such cases. In all cases, the concurrent entities are unilateral, with a left-sided predominance and a male prevalence. The diagnosis of megacalycosis is presumed in four of the cases by normal function and prompt emptying of the calyceal systems on diuretic renography and/or urography. The presence of normal caliber renal pelvis interposed between the dilated collecting system and the distal dilated ureter without evidence of vesicoureteral reflux implies the coexistence of ipsilateral idiopathic megaureter. The patients usually present because of urinary tract infection and/or calculus formation, but respond well to conservative therapy.

Adolescent↗
PubMed1987

Posterior sagittal exposure for reconstructive surgery for cloacal anomalies.

We treated seven girls with a cloacal anomaly through a posterior sagittal exposure. Six patients, aged 5 months to 2 1/2 years, underwent a primary reconstructive operation with urethroplasty, vaginoplasty, and posterior sagittal anorectoplasty as a single procedure. All had undergone diverting sigmoid colostomies as newborns, four had previous vesicostomies, and one had a vaginostomy. The seventh girl, a 9-year-old, had undergone a number of attempts at reconstruction. All underwent endoscopy and contrast studies of the cloaca before definitive reconstruction. This preoperative evaluation gave necessary information regarding the length and caliber of the cloacal channel and the level of confluence of the urinary, genital, and intestinal tracts. However, major decisions regarding reconstruction were often possible only in the operating room. To construct a neoanus with optimal sphincteric control, all seven underwent posterior sagittal anorectoplasty. Two required laparotomies to mobilize additional colonic length. Three developed urethrovaginal fistulae after repair. Critical decisions regarding urethral and vaginal reconstruction depend on the findings at cystoscopy and operation. The posterior sagittal approach gives excellent exposure for these decisions and the subsequent reconstruction of three functioning perineal orifices.

Child↗
PubMed1987

Urolithiasis in childhood: current management.

During the past 12 years, 62 children with urinary stones have been treated at the Children's Hospital of Philadelphia. The most common presenting symptoms were abdominal or flank pain (45%), recurrent or persistent pyuria (35%), and gross hematuria (21%). Twenty-two patients had associated congenital urologic anomalies. Infection-related struvite stones were most common and were found in 18 children, of whom 15 were found to have anatomic abnormalities. Eighteen of 28 children evaluated for a metabolic cause were found to have an abnormality, most frequently hypercalciuria. No predisposing factors could be found in 16 of the 62 patients. Forty-four (87%) children had upper urinary tract stones. Twelve of 15 bladder stones were in children with a neuropathic bladder and all were related to infection. Treatment was directed to the correction of anatomic and metabolic predisposing causes, as well as to removing the stones. Fifteen patients passed stones ranging in size from 2 to 6 mm. Forty-six surgical procedures were performed in 43 children. Pyelolithotomy and cystolithotomy were the most frequent procedures. There were three residual stones and five recurrences. Of the 29 operations for upper urinary stones reviewed, 17 might today be considered suitable for percutaneous nephrostolithotripsy or extracorporeal shockwave lithotripsy. Possible future stone management will be discussed in light of this analysis.

Adolescent↗
PubMed1987

Omphalocele, cryptorchidism, and brain malformations.

Nineteen male infants died with a large omphalocele and 52% had associated cryptorchidism. However, two different groups with both omphalocele and cryptorchidism were recognized: (1) Eleven patients with omphalocele without brain malformation and an incidence of undescended testes not significantly different from the normal population; (2) Eight patients with omphalocele and brain malformation all having cryptorchidism. A comparison of the groups indicated that intact intraabdominal pressure during intrauterine life is not a main driving force of testicular descent, whereas normal testicular descent may occur only when the brain is normally developed. Whenever a child with omphalocele and cryptorchidism is examined, careful evaluation of the central nervous system is indicated. This triad of malformations may have prognostic and therapeutic implications.

Brain↗
PubMed1987

Onlay island flap in the repair of mid and distal penile hypospadias without chordee.

The onlay island flap is a variation of the transverse preputial island flap for hypospadias repair. It is useful in patients without fibrous chordee whose meatus is mid penile or subcoronal. This technique was used in 50 patients and the results were compared to those of 34 patients undergoing the Mathieu meatal-based flap (flip-flap) during the same period. The cosmetic results with the onlay island flap were quite satisfactory and the complication rate was 6 per cent, which was identical to that observed with the Mathieu repair. The onlay island flap is applicable particularly in patients with mid shaft hypospadias without chordee, if the meatus is too proximal for a Mathieu repair and in patients with distal penile hypospadias with deficient ventral skin.

Humans↗