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Biomedical subjects

F D Stephens

Publications and source records attributed to F D Stephens.

At least 37 records · Page 2Linked to original sources
PubMed1983

Cecoureterocele: morphology and clinical correlations.

A unique necropsy specimen of a cecoureterocele, together with the bladder and urethra in a female newborn, was studied to determine the structure of the ureterocele and the accompanying vesicourethral sphincter. The ureterocele within the bladder base and the entire urethra were examined macroscopically and microscopically in serial sections. The ureterocele and its cecal extension were amuscular. The bladder neck, and the involuntary and voluntary sphincters were attenuated or devoid of muscle in the quadrant beneath the ureterocele and its cecal extension. These findings were correlated with the clinical features of 2 living patients with comparable ureteroceles who had urinary incontinence following surgical excision of the ureteroceles.

Child, Preschool↗
PubMed1982

Ureterovascular hydronephrosis and the "aberrant" renal vessels.

The pelvis, an angulated upper segment of the ureter and the lower anterior renal segmental vessels entangle to produce hydronephrosis. However, which of the 3 structures provokes obstruction is conjectural. The structural relations in this anomaly were compared to those of normal kidneys, hydronephroses from other causes and nonrotated kidneys. This anomaly was unique in that the pelvis and ureteropelvic junction bulged over the lower hilar segmental vessels instead of under as in other forms of hydronephrosis. Transient or permanent defects of medial rotation of the renal pelvis may account for the vulnerability of the ureteropelvic junction to obstruction by the lower anterior segmental branch of the renal artery, which was not aberrant in all the examples studied.

Aged↗
PubMed1981

The pathogenesis of renal dysplasia. I. Quantification of hypoplasia and dysplasia.

In order to assess the relative effects of abnormal ureteric orifice position and abnormal urodynamics on the morphogenesis of hypoplasia and dysplasia in kidneys obtained from infants, we devised a method of quantifying the renal structures. The method was based on radial glomerular counts which ranged from zero to normal (seven to nine), a score for dysplastic structures, and the ratio of normal to abnormal tissues present. These three values, when plotted against each other, correlated closely. The glomerular count, with occasional minor adjustment for inconsistencies, was the best parameter of hypodysplasia. Severe to moderate grades of hypodysplasias fell in the low and middle ranges and hypoplasia through to normal in the highest range. By grading kidneys in this way, we were able to compare the effects of ureteral ectopy and abnormal urinary dynamics on the developing kidney.

Histological Techniques↗
PubMed1981

The pathogenesis of renal dysplasia. III. Complete and incomplete urinary obstruction.

We graded obstructed kidneys of infants on the hypodysplasia scale to assess the influence of complete and partial obstruction on the pathogenesis of hypodysplasia. Kidneys with complete obstruction exhibited severe grades; those with partial ureteral obstruction had near normal grades. Those kidneys subjected to partial urethral obstruction ranged from mild to severe grades which correlated with degrees of lateral ectopy of the urethral office. Renal parenchymal development was impaired by complete obstruction but was tolerant to incomplete obstruction. Abnormal orifice positions associated with urethral obstructions were considered to be manifestations of ectopic ureteric buds and the hypodysplasia to be evidence of abnormal induction of abnormal renal blastema.

Humans↗
PubMed1981

The pathogenesis of renal dysplasia. II. The significance of lateral and medial ectopy of the ureteric orifice.

Renal hypoplasia and dysplasia may be primary malformations linked to a panureteric bud deformity or result from damage to the developing nephrons caused by abnormal urodynamic pressures, Kidneys with misplaced ureteric orifices were graded, according to histologic criteria, on the hypodysplasia scale. With lateral ectopy of the ureteric orifices with and without congenital urethral obstruction, the grades correlated with specific orifice positions. The grades of kidneys with caudal ectopy of the ureters indicated a more general correlation. Dysgenesis of the bud and nephrogenic mesenchyme may account for the renal hypodysplasia when the ureteric orifice is found to be ectopic.

Female↗
PubMed1979

The vesicoureteral hiatus and paraureteral diverticula.

Two ureteral sheaths and the vesical musculature combine to form a watertight ureterovesical junction but the precise anatomy and function of each component are still somewhat contentious. The morphology was studied in postmortem specimens of children with and without paraureteral diverticula and urethral obstruction, and function by deductive reasoning from radiographic and surgical observations in living children. Waldeyer's fascia (the superficial sheath) of the ureter was found to seal the potential space between the tunnel wall and the ureter, and deficiencies were associated with hiatal hernias. The deep sheath provided anchorage of the ureter to the trigone and through the attachments of the superficial sheath to the bladder wall. Both sheaths and the tunnel muscles could be identified clearly and dissected precisely at operations involving the ureterovesical junction to facilitate the surgical procedures.

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↗
PubMed1978

The persisting mesonephric duct: high junction of vas deferens and ureter.

We describe 9 examples of a rare congenital anomaly in which the unduplicated ureter joined the vas and exhibited long persisting mesonephric ducts that resembled the ureter rather than the vas. Some of the kidneys were unexpectedly well developed. It is proposed that a cranial ectopic ureteral bud may have induced a metanephric kidney in the region of the mesonephros or the ectopic bud and the metanephric blastema were displaced cranially.

Abnormalities, Multiple↗
PubMed1978

The vesicoureteral hiatus and paraureteral diverticula.

Two ureteral sheaths and the vesical musculature combine to form a watertight ureterovesical junction but the precise anatomy and function of each component are still somewhat contentious. The morphology was studied in postmortem specimens of children with and without paraureteral diverticula and urethral obstruction, and function by deductive reasoning from radiographic and surgical observations in living children. Waldeyer's fascia (the superficial sheath) of the ureter was found to seal the potential space between the tunnel wall and the ureter, and deficiencies were associated with hiatal hernias. The deep sheath provided anchorage of the ureter to the trigone and through the attachments of the superficial sheath to the bladder wall. Both sheaths and the tunnel muscles could be identified clearly and dissected precisely at operations involving the ureterovesical junction to facilitate the surgical procedures.

Child↗
PubMed1977

"H-type" urethroanal fistula.

Stephens and Smith have recently described a urethroanal connection through which urine was passed preferentially into the otherwise normal rectum at the pectinate line. Other authors have reported similar deformities. The term "congenital 'H-type' anourethral fistula" was proposed for this rare anomaly by deVries and Friedland in 1974. In this communication, we describe two examples of the "H-type" urethroanal fistula (Fig. 1). Each patient also had tracheoesophageal fistula. One patient (R.P.), now 11 yr of age, has had successful correction of the anomaly. The other patient (T.McC.), a small premature baby whose uroanal deformity was investigated radiographically, died of sepsis and uremia. The anatomical relationships in this baby were investigated histologically in the autopsy specimen by means of serial sections. From this study, it has been possible to determine the sphincteric anatomy and to suggest a possible pathoembryology of the defect.

Child, Preschool↗
PubMed1977

Techniques and results of urodynamic evaluation of children.

Simultaneous recording of intravesical pressure, urine flow rate and anal sphincter electromyography was undertaken in 25 children with a variety of urological problems. Urethral pressure profile measurement was obtained in 3 of these patients and was used as an adjunct to cystometry alone in 5 others. The diagnostic patterns that emerged were useful in selecting specific pharmacologic and surgical therapeutic measures.

Adolescent↗
PubMed1977

Paraureteral diverticula. Associated renal morphology and embryogenesis.

A study was made of paraureteric diverticula, the associated ureteric orifices, and the accompanying kidneys. It was shown that the kidney was more abnormal as the ureteric orifice position lay more laterally and into the diverticulum. The fascial arrangements of the terminal ureter and the related diverticulum were examined. When the ureter opened totally within the diverticulum, both structures showed a single investment of fascia, suggesting a common embryologic orgin of the two structures. When the ureter opened either separately into the bladder or on the verge of the diverticulum, the urter and the adjacent diverticulum each had separate fascial investment, suggesting a different etiology for the formation of this type of diverticulum. A total of 25 single-system specimens were employed for the above study. In the series there were an additional three duplex systems associated with paraureteric diverticula in shich the kidney morphology followed the above pattern but the fascial arrangements were different. Based on the observations of this investigation, it is suggested that the renal morphology is governed by the position of the ureteric orifice in the diverticulum and that the term vesical hiatal diverticula be used to denote those diverticula occurring in the vicinity of the ureteric orifice. It is further suggested that the diverticulum which engulfs the ureteric orifice be called paraureteral, and those with separate orifices in the bladder be termed periureteral to differentiate the embryologic from the pulsion etiologies.

Autopsy↗
PubMed1977

Fused kidneys: morphologic study and theory of embryogenesis.

A study was made of 50 fused kidneys; 41 postmortem specimens and 9 living patients' records were reviewed. Three patterns of renal fusion were identified--midline fused horseshoe kidney [15], laterally fused horseshoe kidney [21], and crossed renal ectopia [14]. These morphologic renal patterns were correlated with coexisting abnormalities of the urinary tract and other organ systems. A high incidence of hydronephrosis of varied etiology, vertebral, and anorectal defects was found in the laterally fused horseshoe and crossed renal ectopic groups. A theory of embryogenesis was developed to explain the asymmetric patterns of renal fusion exemplified by laterally fused and crossed fused kidneys. It was based on the effects that the lateral flexion and rotation of the hind end in the 4- to 5-mm embryo exert on the relative positions of the nephrogenic cords and wolffian ducts.

Child↗
PubMed1977

Ureteral muscle tone in prevention of vesicoureteral reflux.

Three experiments were devised to examine three aspects of the mechanism of the ureterovesical valve in dogs: muscle defects, orientation of muscle in the submucosal segment of the ureter, and the support afforded by the firm bladder base. The ureterovesical valve mechanism of the dog was found to be inefficient when the roof of the submucosal segment was denuded in situ of its muscle. The valve remained efficient when the extravesical ureter, with its circular and oblique arrangement of muscle, was substituted for the normal submucosal ureter with its longitudinally disposed muscle. The efficiency of the ureterovescial junction was not impaired by substituting a floating bed of bladder muscle for the firm platform of the bladder base in which it is normally embedded. The bladder muscle of the hiatus was not effective in the prevention of vesicoureteral reflux if the submucosal segment was rendered inefficient as a sphincter by excision of the muscle in its roof or by excision of the segment. Muscle in the submucosal segment, arranged in either longitudinal or circular fashion, was an effective activator of the mechanical valve. Presumably, the tonic action of the smooth muscle is the activator that ensures the efficiency of the one-way flow flap-trap regulator of the ureterovesical junction.

Animals↗
PubMed1976

The natural history of reflux and long-term effects of reflux on the kidney.

Spontaneous cessation of vesicoureteral reflux occurred in 42 per cent of 102 patients. It ceased in 65 per cent of the patients with unilateral reflux, in 50 per cent of those with bilateral reflux in normal caliber ureters and in 9 per cent of those with bilateral dilated ureters. Renal parenchymal changes were seen most frequently in patients with urinary infection after diagnosis. The likelihood of such infections lessened if reflux ceased. Proportionately more male than female subjects were free of infection. Renal damage may follow even 1 episode of infection. Lesions appeared with equal frequency during the entire followup period, whereas urinary infection was more common in the 5-year period after diagnosis. Renal damage was more likely to occur in kidneys that were already abnormal. Reflux should be controlled surgically if urinary infections occur after diagnosis and during long-term chemotherapy and careful observation. In the absence of infection indications for operation are infrequent. Non-surgical management may apply to normal caliber ureters and in infancy, while antireflux operation may be considered at diagnosis in dilated ureters, bilateral reflux or in the presence of renal lesions.

Adolescent↗