Urine concentration and enuresis in healthy preschool children.

OBJECTIVES: To determine whether children concentrate their urine overnight and to assess the correlation between specific gravity of a first morning urine specimen and the results of a questionnaire concerning bedwetting, voiding habits, and continence in 47 healthy children aged 3 to 6 years. DESIGN: A prospective observer-blinded consecutive sample. SETTING: Two San Francisco, Calif., preschools. PARTICIPANTS: Forty-seven children attending preschool during the study period. MEASUREMENTS/MAIN RESULTS: Forty of 47 children had a urine specific gravity greater than 1.020. None of these children wet the bed during this study, although four (11%) of 36 had a history of bedwetting. Furthermore, seven children with a urine specific gravity of 1.015 or lower had a history of bedwetting and wet the bed during this study. A voiding frequency of six or more times per day, by history, was associated with a 3:1 relative risk of bedwetting but did not segregate children with primary enuresis from those with secondary enuresis. CONCLUSIONS: Our results indicate that healthy children aged 3 to 6 years are able to concentrate their urine. In addition, urine specific gravity was an accurate predictor of the presence of nocturnal enuresis in this group of children. Our results suggest that a specific gravity of the first morning urine specimen should be correlated with appropriate history before extensive diagnostic evaluation or empiric therapy is performed in children with nocturnal enuresis.

Laparoscopy for the evaluation and management of the nonpalpable testicle.

OBJECTIVE: To assess the usefulness of laparoscopy for the diagnosis and treatment of the nonpalpable testicle and to evaluate the results of laparoscopic orchidopexy. METHODS: We retrospectively reviewed the charts of 91 laparoscopies performed over a period of 4 years. We reviewed the following parameters: findings, complications, patency of the processus vaginalis, appearance of the cord structures, and the success of the different procedures performed for the intra-abdominal testicle. RESULTS: Fourteen patients had bilateral and 77 unilateral nonpalpable testicles. The mean age of the patients was 39.5 +/- 50.8 months. There were three laparoscopic complications (3.2%) one of which was a major bowel laceration. Laparoscopy defined the intra-abdominal anatomy accurately in 90 of the 91 cases Of the 26 intra-abdominal testicles above the ring, a one-stage laparoscopic orchidopexy was performed in five and a single-stage standard orchidopexy in seven. All of these testicles remain viable and are in good position. Eight patients underwent a staged Fowler-Stephens orchidopexy with laparoscopic clipping of the spermatic vessels as the first stage. Of these, a second-stage open orchidopexy was performed in five and a laparoscopic orchidopexy in three. Testicular atrophy occurred in two of the patients who underwent the second-stage open orchidopexy. Three one-stage Fowler-Stephens orchidopexies were performed with testicular atrophy occurring in two of these testicles. Laparoscopic orchiectomy was performed on two patients. CONCLUSIONS: Laparoscopy is a valuable tool in the diagnosis and treatment of the nonpalpable testicle. Laparoscopic orchidopexy may decrease the rate of testicular atrophy since most of these can be performed laparoscopically in one stage, thus preserving the vascular supply.

Detrusorrhaphy for repair of unilateral vesicoureteral reflux: report of 76 patients using a modified technique.

OBJECTIVE: To present our results for repair of unilateral vesicoureteral reflux in 76 children using a modified technique of detrusorrhaphy. METHODS: A retrospective chart review was performed for 76 children who underwent repair of unilateral vesicoureteral reflux by a modified technique of detrusorrhaphy. Of the 76 refluxing ureters, 12 were associated with historically refluxing contralateral ureters. In addition, 72/76 were grades II to IV; 4/76 grade V; three had a paraureteral diverticulum; four completely duplicated collecting systems; and two had associated ureteroceles. The surgical technique was modified to preserve both the obliterated umbilical artery and superior vesical pedicle and to minimize trigonal distortion through dissection lateral to the trigone in a direct path to the bladder neck. RESULTS: Seventy-five of 76 ureters were successfully repaired (99%). The remaining ureter showed initial improvement to grade I reflux and spontaneous resolution by 1 year. Obstruction did not occur. Three episodes of "new onset" contralateral vesicoureteral reflux were noted postoperatively. This represents a substantial decrease in incidence (3.9%) when compared with previously reported series (18%). CONCLUSION: Detrusorrhaphy is a reasonable treatment of unilateral vesicoureteral reflux with utility in the full range of anatomic associations. This approach is also associated with a lower incidence of new onset, contralateral reflux when compared with intravesical surgery.

Therapeutic laparoscopy for intra-abdominal testes.

Fourteen laparoscopic surgical procedures were performed in 10 children with 11 intra-abdominal testes. In addition to localizing the testes, laparoscopy aided in the surgical approach. In 8 patients, the first phase of a two-stage Fowler-Stephens orchiopexy was performed. Five children underwent an open surgical procedure three months later and have a viable testis in the scrotum after at least nine months of follow-up. In 5 patients (6 testicles), laparoscopy was used to dissect the testis. Three patients underwent the second phase of the two-stage Fowler-Stephens procedure laparoscopically. In all 3 patients, the testicle could be easily mobilized into the scrotum. Two other testicles were mobilized by dissecting the spermatic vessels up to the renal hilum laparoscopically; this allowed the intra-abdominal testes to come into the scrotum without dividing the spermatic vessels. In one teenager with a small intra-abdominal testis and a normal contralateral testis, laparoscopic orchiectomy was performed. We believe laparoscopy has a role both diagnostically and surgically in the treatment of intra-abdominal testes.

Ultrasound diagnosis of tunica albuginea cyst: clinical perspective.

Two case reports of tunica albuginea cysts are presented. Imaging of this lesion by high resolution ultrasonography and the impact of this technique on management are considered.

Renal cell carcinoma: incidental diagnosis and natural history: review of 235 cases.

Two hundred thirty-five cases of histologically proved renal cell carcinoma (1976-1987) were reviewed to determine the impact of incidental tumor detection on the natural history of this cancer. One hundred sixty-eight patients (71.5%) presented with clinical signs and/or symptoms of renal pathology. Of these, 25 (18%) were investigated without consideration of renal cell carcinoma in the differential diagnosis. Sixty-seven cases (28.5%) were diagnosed as an incidental finding on diagnostic imaging for extrarenal symptomatology. Approximately 30 percent of patients were found to have metastatic disease on initial presentation regardless of incidental, or suspected discovery of these tumors. Stages A and B tumors were encountered with equal frequency in patient groups with both suspected and incidental diagnosis. Intravenous pyelography was the diagnostic modality used to detect the diagnosis in 83 percent of cases. While incidental detection of renal cell carcinoma has become more frequent than in previous years, it appears to have impacted minimally on the discovery of earlier stage tumors than those with presenting clinical symptoms. In contrast to prior reports, our data show that the natural history of renal cell carcinoma is not significantly altered by the incidental detection of tumor.

Pediatric ureteropelvic junction obstruction treated with retrograde endopyelotomy.

OBJECTIVES: To determine the feasibility of retrograde endopyelotomy in the management of pediatric ureteropelvic junction (UPJ) obstruction. METHODS: We treated 2 boys aged 4 and 6 years with the Acucise endopyelotomy device for symptomatic ureteropelvic junction obstruction. The Acucise device was placed over a Lunderquist guide wire with fluoroscopic guidance only and routine Double J catheters were left in situ for 6 weeks after the procedure. The morbidity of the treatment and the short-term outcome were assessed. RESULTS: There were no acute complications and short-term follow-up results were satisfactory as determined by intravenous urography and diuretic renography. CONCLUSIONS: Ureteropelvic junction obstruction in children may be treated by retrograde endopyelotomy with the Acucise device. The principal potential advantage of this procedure is reduced morbidity. Our findings suggest that further evaluation is warranted.

Fetal lower urinary tract physiology: in vivo studies.

Fetal lower urinary tract function is under continuous maturation throughout gestation and is an integrated neurophysiologic event by late gestation. Preliminary in vivo study suggests that peripheral and central nervous system regulation of micturition occurs in utero, and that these events can be modulated pharmacologically and through external stimulation. Normal bladder function in utero is essential to normal development of the entire fetus, and in utero modulation of bladder dysfunction may be feasible as our understanding and diagnostic acumen increase.

Renal hemodynamic and functional effects of 10 days' partial urinary obstruction in the fetal lamb.

We studied fetal lambs to define the renal pathophysiology of chronic in utero partial bladder outlet obstruction. These fetal lambs, 115 to 120 days gestation (term = 145 days), underwent urethral ligation, placement of a urachal catheter and positioning of an ultrasonic flow transducer around the left renal artery. Partial obstruction was created by placing a narrow connector between the urachal and an amniotic catheter. In control animals a large connector was placed to allow free drainage of the bladder into the amniotic cavity. Renal blood flow was measured daily, and urine was collected at days 5 and 10 to evaluate renal function. In control animals, no significant changes in any parameters were observed. In the partially obstructed fetal lambs, renal blood flow increased to 165% of baseline after 5 days; from 5 to 10 days, it decreased, but remained above baseline values through 10 days (128%). Urine production dropped significantly after 10 days (67%). Glomerular filtration rate increased slightly after 5 days (127%), but decreased after 10 (56%). Filtration fraction steadily decreased after 5 (70%) and 10 days (33%). Fractional and total sodium excretion did not change. Renal blood flow increases, filtration fraction decreases and renal function trends progressively diminish in response to partial bladder outlet obstruction over a period of 10 days in the fetal lamb.

Urodynamic and clinical follow-up of 28 children after gastrocystoplasty.

OBJECTIVES: To determine the efficacy of gastrocystoplasty in creating a large and compliant urinary reservoir. PATIENTS AND METHODS: Twenty-eight children (14 boys, 14 girls), with a median age of 9 years (range 4-17), were evaluated before and for a median of 2 years and 5 months after gastrocystoplasty. Evaluation included urodynamic and renal function studies and a survey of their post-operative complications and their sense of well-being. Renal function was assessed by ultrasound and serum creatinine, and electrolytes were measured. RESULTS: After gastrocystoplasty bladder size increased, compliance improved, hydronephrosis decreased or was stable, and renal function remained stable. There were minimal complications and the children's subjective impression of their well-being was markedly improved. CONCLUSION: Gastrocystoplasty, using our surgical technique, is a reliable method of creating a large and compliant urinary reservoir. Advantages include the absence of clinical urinary tract infections, the absence of mucus and the preservation of renal function. Complications, such as haematuria, dysuria and hypochloraemic alkalosis, might be avoided by excluding the antrum from the gastrocystoplasty, maintaining the child on a normal salt-containing diet, employing catheterization or buffering the urine in children with normal urethral sensation.

Role of nitric oxide in fetal lower urinary tract function.

We studied the role of nitric oxide (NO) in normal function of the lower urinary tract in fetal lambs. Fetal surgery was performed in pregnant ewes at 118 days' gestation (term 145-days) to place arterial, venous, and double-lumen urachal catheters. Five animals had a catheter secured in the distal urethra (to measure voided volume), and six underwent ligation of the urethra. Urodynamic studies were performed via the urachal catheter under baseline conditions, during systemic blockade of NO synthesis with N omega-nitro-L-arginine, and with systemic NO stimulation by L-arginine 48 hours postoperatively. Nitric oxide blockade caused an 88% mean increase in bladder capacity (volume to initiation of voiding) (p < 0.001) and a 5.8-fold increase in mean postvoid residual volume (p < 0.0001) despite normal maximal bladder pressures, suggesting inadequate sphincteric relaxation. Qualitatively, NO inhibition increased the presence of low-level bladder contractions and caused a trend toward decreased bladder compliance. Increase of NO substrate by L-arginine infusion restored baseline findings if performed after N omega-nitro-L-arginine. Stimulation of NO by L-arginine infusion caused continuous efflux of the infusate secondary to a persistently open sphincter. In conclusion, NO is active in the function of the lower urinary tract in the fetal lamb and appears to influence both sphincter and detrusor activity.

The prune-belly syndrome: current insights.

The prune-belly syndrome comprises a constellation of well-established physical findings, yet the cause and management remain controversial. This review focuses on the current understanding of its pathogenesis and characterizes the fetal and neonatal diagnosis and management. Other associated anomalies are discussed to understand better the factors affecting treatment and prognosis as these patients grow into childhood and beyond.

Effects of endothelium-derived nitric oxide on renal hemodynamics and function in the sheep fetus.

We investigated the effects of the endothelium-derived nitric oxide system on renal hemodynamics and function during the 3rd trimester in a chronically catheterized fetal sheep preparation. Acetylcholine caused a significant decrease in renal vascular resistance (60% of the baseline value) as compared with aortic constriction (142% of the baseline value). The effects of acetylcholine could be blocked by prior administration of N omega-nitro-L-arginine (renal vascular resistance = 102% of baseline). Sodium nitroprusside also caused a significant drop in renal vascular resistance (63% of baseline), but this could not be blocked by N omega-nitro-L-arginine (77% of baseline). Infusion of N omega-nitro-L-arginine with blood pressure maintained at a constant level resulted in a significant increase in renal vascular resistance (148% of the baseline value) as compared with saline alone (94% of baseline). Glomerular filtration rate increased after saline infusion (156% of the baseline value), but this increase was blocked by N omega-nitro-L-arginine (87% of baseline). Sodium excretion also increased (340%), and this increase was blunted by N omega-nitro-L-arginine (235%). We conclude that basal production of endothelium-derived nitric oxide results in ongoing renal vasodilation in 3rd-trimester fetal sheep, maintaining baseline renal blood flow. The endothelium-derived nitric oxide system can also be stimulated to an increased level of activity, and its blockade partially prevents the homeostatic response of the fetus to volume and salt overload.

Human papillomavirus type 6 in grade I transitional cell carcinoma of the urethra.

Of 4 patients who underwent cystourethroscopy, biopsy and laser excision of suspected urethral condylomata acuminata 3 had coexistent grade I papillary transitional cell carcinoma of the urethra. Human papillomavirus type 6 messenger ribonucleic acid was demonstrated within biopsy specimens using tritium-labeled single-stranded antisense ribonucleic acid probes. Compared to condylomata the papillary transitional epithelium expressed less viral message, which might be expected in an epithelium that does not show full squamous epithelial or koilocytotic differentiation. Among these patients there was 1 papillary transitional lesion in the bladder that, although histologically similar, did not express human papillomavirus message, suggesting differential susceptibility of epithelium between the bladder and urethra. The finding of active human papillomavirus transcription within the urethral papillary transitional lesions raises the possibility of an active role for the virus in the pathogenesis of these lesions. These findings broaden the spectrum of epithelial types reported to support human papillomaviruses and provides impetus for a wider search for these viruses in other transitional cell neoplasms.

Induction of insulin resistance in normal adipose tissue by uremic human serum.

An incubation of uremic human serum with normal rat adipose tissue will make the subsequently isolated adipocytes less responsive to insulin. To examine the extent of insulin resistance, we obtained sera from nondiabetic, uremic patients, who had not undergone dialysis therapy. The sera were then dialyzed (3500 molecular-weight cutoff) for 18 hr against a defined culture medium to eliminate possible in vitro effects of altered levels of end-product metabolites, electrolytes, and metabolic substrates. After an incubation of epididymal fat tissue from normal rats, for 3 hr with the dialyzed sera (50% vol/vol), cells were isolated and washed. The insulin stimulation of 14C-glucose (0.2 mM) incorporation to 14CO2 and total lipids was significantly reduced in the adipocytes pretreated with sera from 19 of the 29 uremic patients. Although elevated in the uremic patients, the sera levels of insulin, and parathyroid and growth hormones were not correlated to insulin resistant activity. Furthermore, incubation of adipose tissue for 3 hr with insulin, glucagon, or PTH did not produce resistance. The uremic sera reduced glucose utilization equally at 0.2 and 50 mM glucose, suggesting that the insulin resistance was induced additionally at a site distal to the glucose transport system. However, the concentration of insulin (22 microunits/ml) required for half-maximal stimulation of glucose metabolism was not altered by pretreatment with uremic serum. Also, neither the isoproterenol-stimulated lipolysis nor the inhibition of this cellular event was influenced by pretreatment with uremic sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Testicular imaging.

Clinicians have relied on radionuclide scanning for evaluating acute scrotal pain and on ultrasonography for chronic scrotal pain and anatomic lesions (testicular and paratesticular structures). This review reinforces the utility of these established imaging techniques and also introduces color Doppler ultrasonography as an integral component in the advancement of testicular imaging, particularly in effective and timely diagnosis of spermatic cord torsion. The expanding capability of MR imaging for scrotal disorders is presented.

Clean intermittent catheterization in boys using the LoFric catheter.

PURPOSE: We compared a recently developed hydrophilic catheter to the standard polyethylene catheter in regard to hematuria, infection and patient satisfaction. MATERIALS AND METHODS: A hydrophilic LoFric or standard Mentor catheter was assigned at random to 17 and 16 boys, respectively, who were skilled in intermittent self-catheterization. They were evaluated by weekly urinalysis and a questionnaire. RESULTS: Significantly fewer episodes of microscopic hematuria occurred in the LoFric than Mentor catheter group (9 episodes in 6 subjects versus 19 episodes in 11, p < 0.05). There were also fewer episodes of bacteriuria in the LoFric group but the difference was not statistically significant. Mean scores plus or minus standard deviation on a visual analogue scale with 0 equal to most and 10 equal to least favorable were LoFric 3.3 +/- 2.8 versus Mentor 4.9 +/- 2.7 for catheter convenience and 2.7 +/- 2.4 versus 4.2 +/- 2.6 for insertion comfort, significantly favoring the LoFric group (p < 0.05 for both). Of the 16 LoFric subjects 13 preferred to continue its use, particularly those with a history of urethral trauma or sphincteric spasm. CONCLUSIONS: In boys the LoFric catheter appears to cause less trauma. Although it is not reusable and is more expensive than the standard catheter, satisfaction is higher with the LoFric device and for select patients it has significant advantages.

Renal preservation despite 35 days of partial bladder obstruction in the fetal lamb.

To determine whether the increase in renal blood flow and preservation of renal function that we demonstrated after 10 days of chronic partial bladder obstruction in the third trimester fetal lamb also occur after earlier longer obstruction, we modified our preparation and studied the effects of 35 days of obstruction begun during the second trimester. Partial bladder obstruction was created in 10 fetal lambs at 90 days of gestation (term equals 147 days). At repeat surgical intervention 28 days later vascular catheters and a left renal artery flow transducer were placed, and catheters were externalized. We then studied renal blood flow and function at gestational ages 120 days and 125 days after 30 days and 35 days of obstruction, respectively. Tissue was obtained for histology at the time of sacrifice. Eight control fetal lambs without obstruction were studied in a similar way. Bilateral hydroureteronephrosis was noted in all fetal lambs after partial obstruction, whereas the kidneys and bladders of the control animals had a normal appearance. Renal blood flow was higher in the obstructed fetal lambs than in controls (20.2 +/- 4.9 versus 10.2 +/- 0.9 ml. per minute per kg., p < 0.05 after 30 days and 17.1 +/- 2.7 versus 9.7 +/- 0.9 per minute per kg., p < 0.05 after 35 days). There was no evidence of decreased renal function by any parameter and, in fact, glomerular filtration rate and urine volume were increased after 30 days of obstruction (1.59 +/- 0.32 versus 0.69 +/- 0.07 ml. per minute per kg., p < 0.05 and 15.7 +/- 4.3 versus 5.2 +/- 0.8 ml. per hour per kg., p < 0.05, respectively). Histological studies demonstrated normal architecture of the kidneys but thinned cortex. We conclude that the physiological responses of the fetus are such that partial lower urinary tract obstruction in our preparation results in a prolonged increase in renal blood flow and preservation of renal function.

Refined microscopic urinalysis for red blood cell morphology in the evaluation of asymptomatic microscopic hematuria in a pediatric population.

PURPOSE: The use of refined microscopic urinalysis for the presence of dysmorphic red blood cells (RBCs) has been evaluated in children and adults with a known source of hematuria. We examined the clinical usefulness of this study in a pediatric population with an unknown source of hematuria. MATERIALS AND METHODS: Children 12 years old or younger referred for evaluation of asymptomatic microscopic hematuria exhibiting 4 or more RBCs per high power field were enrolled in this study. Patients provided a first morning urine sample subjected to refined urinalysis for RBC morphology. Standard evaluation of patients was performed until a final diagnosis of the hematuria source was identified. RESULTS: A total of 44 patients completed the study. Refined urinalysis revealed pure dysmorphic RBCs in 22 patients, pure isomorphic RBCs in 8 and mixed isomorphic/dysmorphic RBCs in 14. The presence of dysmorphic RBCs correctly predicted a glomerulotubular source of hematuria in 29 of 36 patients (sensitivity 83%, specificity 81%), while the presence of isomorphic RBCs predicted a uroepithelial source of hematuria in 2 of 8 patients (sensitivity 25%, specificity 22%). Hematuria and 2+ proteinuria (100 mg./dl.) were more sensitive (100%) and specific (83%) than the presence of dysmorphic RBCs in predicting glomerulotubular hematuria. CONCLUSIONS: We believe that this is a costly test offering little additional information to the evaluation of microscopic hematuria in children. A thoughtful history and physical examination with microscopic urinalysis and dipstick for proteinuria provide an equal amount of diagnostic information. We do not recommend its routine use in the evaluation of microscopic hematuria in children.