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R Medel

Publications and source records attributed to R Medel.

15 recordsLinked to original sources
PubMed2002

Detrusor after-contractions in children with normal urinary tracts.

OBJECTIVE: To assess the clinical significance of after-contractions (A-Cs) in children with normal urinary tracts. PATIENTS AND METHODS: Urodynamic records obtained in 315 children with urinary infection or enuresis were reviewed retrospectively; 184 were selected for analysis of A-Cs. All patients had normal urinary tracts and none showed signs of an overt neuropathy. The urodynamic method comprised standard measurements of pressures and flowmetry (42 had video-urodynamic studies). RESULTS: After-contractions occurred in 151 of the 184 patients; the incidence tended to decrease with age. The mean amplitude of the A-Cs was 77.9 cmH2O; in 36% of the records it was higher than the voiding contraction. Residual urine was found in 12 of 151 records with A-Cs, but in only one patient was such residual urine confirmed in control voids. The patterns were assessed in 131 patients: in 36% they resembled stop-test responses, in 31% they were preceded by brief peaks of pressure or had jagged limbs, and in 33% they were grossly irregular. In 137 records the content of the bladder was estimated at the start of A-Cs; in 51% the bladder was empty or had evacuated >95% of its content, in 39% 95-80% and in 10% <80%. In only 7% of the patients had the A-Cs started after the voiding contraction had completely subsided. There was no difference in the incidence of A-Cs in girls with enuresis (84%) and girls with a history of urinary infections (85%). Detrusor instability was detected in 81% of the children with A-Cs and in 70% of those without; there was no correlation between the amplitudes of uninhibited detrusor contractions and of A-Cs. Characteristic images of external sphincter activity were found in only three of 14 video-urodynamic recordings with A-Cs. CONCLUSION: After-contractions are common in children with normal urinary tracts but they tend to disappear with age. In clinical urodynamics they are of limited practical use because their appearance is unpredictable and there are artefacts related to recording the final phase of micturition. The relationship with detrusor instability may be explained as a coincidence of two common but unrelated findings, and A-Cs are unrelated to urinary infection. External sphincter activity is not the only cause of A-Cs and when it occurs it does not alter the course of voiding, as it does in neuropathic dysfunctions. As their clinical significance is uncertain, treatment of A-Cs is not advocated.

Adolescent↗
PubMed2002

Bladder function associated with posterior urethral valves after primary valve ablation or proximal urinary diversion in children and adolescents.

PURPOSE: We retrospectively reviewed 2 series of patients with posterior urethral valves treated initially with valve ablation preceded by bilateral cutaneous ureterostomies or valve ablation alone to evaluate and compare bladder function behavior of each treatment group. MATERIALS AND METHODS: From 1970 to 1983, 19 males 22 days to 21 months old with posterior urethral valves were treated with 1 of 2 initial surgical approaches, including upper tract diversion, delayed undiversion and ablation in 11 (group 1), and primary valve ablation only in 8 (group 2). Median patient age at the time of cutaneous urinary diversion and primary valve ablation for groups 1 and 2 was 7 and 9 months, respectively. Median duration of bladder defunctionalization was 48 months. All patients were evaluated urodynamically after initial ablation or re-functionalization of the bladder using standard rapid fill cystometry. Median patient age for groups 1 and 2 was 14 and 9.5 years, respectively, at the time of urodynamic testing 16 and 12.6 years, respectively, at followup. RESULTS: Urodynamic assessment revealed detrusor instability in 5 group 1 patients but in only group 2 1 patient. Group 2 patients had significantly lower median end filling pressure (4 versus 15 cm. water, p <0.03) and higher maximum bladder capacity (1.4 versus 0.8, p <0.005) than those in group 1. Group 1 patients had lower compliance than those in group 2 (median 15 versus 82 cm. water, p <0.05). Further analysis showed no difference between groups 1 and 2 in overall median voiding detrusor pressure at maximum flow (51 versus 52.6 cm. water, respectively). Cystometric detrusor under activity patterns were noted in 5 group 1 and 2 group 2 patients. Residual urine volumes were 17%, 31%, 19% and 8% of bladder capacity, respectively, in 2 group 1 and 2 group 2 patients. At final followup 5 group 1 and 2 group 2 patients had renal function deterioration. Two other group 1 patients and group 2 had progression to end stage renal failure. A higher ureteral reimplantation rate was noted in group 1 (63%) than group 2 (6%). CONCLUSIONS: This retrospective study revealed that long-term bladder function of patients with posterior urethral valves treated with temporary supravesical diversion is affected more adversely than those treated with valve ablation alone.

Adolescent↗
PubMed2001

10-Year experience with artificial urinary sphincter in children and adolescents.

PURPOSE: We evaluate specific indications, patient selection and complications of the AMS800 artificial sphincter in children and adolescents with sphincteric incontinence. MATERIALS AND METHODS: Between 1987 and 1997, 39 males and 10 females with a mean age of 14 years (range 7 to 20) with sphincter deficiency underwent artificial urinary sphincter placement. The underlying etiology of incontinence was myelodysplasia in 38 patients, exstrophy-epispadias complex in 7 and urethral trauma in 4. All patients underwent preoperatively conventional urodynamic investigations. Augmentation cystoplasty was done in 9 patients before sphincter implantation and both procedures were performed simultaneously in 2 cases. The cuff was adjusted around the bladder neck in 37 patients and around the bulbar urethra in 12. Followup ranged from 2 to 11 years (mean 7.5). RESULTS: There were 54 sphincter implants in 49 patients. Of the 49 patients 33 (67%) achieved continence, 9 had substantial improvement and 7 remained unchanged after surgery. Erosion occurred in 10 patients due to sphincter infection in 2, mechanical failure in 6 and postoperative changes in bladder behavior in 2. Of these 10 patients with erosion 5 are incontinent and awaiting sphincter replacement, 2 required bladder neck closure and appendicovesicostomy, and 3 are dry without prosthetic replacement. Mean time to erosion was 24.9 months (range 1 month to 9 years), and 3 erosions occurred within 3 months of sphincter placement. Of the 6 patients with mechanical problems 5 regained continence after successful replacement of the sphincter. Only 2 of the 49 cases had postoperative detrusor overactivity requiring augmentation after surgery. Of the 29 patients who performed clean intermittent catheterization preoperatively 3 no longer needed it after implantation of the prosthesis. Finally, 25 (86%) of the 29 patients with a cuff placed around the bladder neck and with no previous surgical repairs at this site achieved continence after implantation whereas only 3 (37.5%) of 8 patients who had undergone prior bladder neck surgical procedures became continent. CONCLUSIONS: This study supports previous reports that the artificial urinary sphincter is effective therapy for sphincteric incontinence. Additionally, in our study previous surgical procedures on the lower urinary tract before sphincter placement increased significantly the rate of postoperative complications.

Adolescent↗
PubMed2001

Bladder functional outcome after delayed vesicostomy closure and antireflux surgery in young infants with 'primary' vesico-ureteric reflux.

OBJECTIVE: To evaluate bladder function by conventional urodynamic investigations in young infants with primary vesico-ureteric reflux (VUR) who had undergone an initial temporary cutaneous vesicostomy followed by later antireflux surgery and vesicostomy closure. PATIENTS AND METHODS: From 1983 to 1990, nine boys (10-360 days old) with primary VUR were treated with an initial vesicostomy, followed by delayed closure of the vesicostomy and the simultaneous surgical correction of reflux. Severe VUR was detected bilaterally in seven and unilaterally in two infants at the time of the initial diagnosis. The mean (SD, range) age at vesicostomy was 12.4 (8, 3-23) months and the duration of bladder defunctionalization 38.7 (25.5, 18-90) months. All patients were assessed urodynamically after closing the vesicostomy, using rapid-fill cystometry with normal saline solution at room temperature. The mean (range) age at the time of urodynamic testing was 7.3 (5-15) years; the mean (SD, range) follow-up was 10.1 (4.1, 5-17) years. RESULTS: Six boys with bilateral VUR underwent successful ureteroneocystostomy; nephroureterectomy was required in one patient. In two patients the VUR resolved with time. After re-functionalization, the mean (SD, range) maximum cystometric capacity, expressed as a percentage of the mean bladder capacity for age, was 1.4 (0.5, 0.6-2.2)%. In three patients the bladder capacity was higher (> or = 40%) than expected for age, while one had diminished (< 70%) bladder capacity. The mean (range) end-filling detrusor pressure was 14.5 (5-42) cmH2O and the mean (SD, range) compliance 24 (13.9, 4-44) mL/cmH2O. Two patients had a compliance of < 10 mL/cmH2O, one of whom had associated unstable detrusor contractions of 90 cmH2O. The mean (SD, range) detrusor voiding pressure at peak flow was 47.3 (16.8, 5-76) cmH2O. One patient had a residual urine volume of 8% of bladder capacity. At the follow-up, only one patient (aged 5 years) with detrusor instability had urinary incontinence. CONCLUSION: This study shows that the bladder of young infants with primary VUR treated with temporary vesicostomy regained normal function after re-functionalization of the lower urinary tract.

Adolescent↗
PubMed2000

Urodynamic findings in boys with posterior urethral valves after treatment with primary valve ablation or vesicostomy and delayed ablation.

PURPOSE: Primary valve ablation and temporary vesicostomy with delayed valve ablation are alternative initial management procedures in neonates and infants with posterior urethral valves. To investigate whether initial vesicostomy followed by delayed valve ablation and simultaneous vesicostomy closure may lead to more alterations in bladder function than primary valve ablation only we retrospectively compared postoperative urodynamic findings in 2 small groups of patients. MATERIALS AND METHODS: From 1980 to 1990, 15 male infants 19 days to 34 months old with posterior urethral valves were treated with 1 of 2 initial surgical approaches, including valve ablation only in 8 (group 1), and primary vesicostomy and delayed valve ablation associated with concomitant vesicostomy closure in 7 (group 2). Mean age at valve ablation and vesicostomy in groups 1 and 2 was 10.8 +/- 11.2 months (range 1 to 35) and 55.4 +/- 43.3 days (range 19 to 151), respectively. Average duration of vesicostomy diversion was 33.6 +/- 18.8 months (range 14 to 70). All patients underwent conventional urodynamics postoperatively using normal saline at room temperature. In groups 1 and 2 mean age at followup was 11.5 +/- 6.6 (range 5 to 16.2) and 9. 4 +/- 3.1 (range 4.10 to 14) years, respectively. Controls comprised 46 age matched males who underwent urodynamics using similar methodology. RESULTS: Postoperative urodynamic assessment of maximum cystometric bladder capacity and the incidence of detrusor instability in each treatment group were not statistically different. In group 1 bladder capacity was significantly higher than that in controls (p <0.0001). In group 2 mean end filling detrusor pressure was increased compared with that in group 1 (29 cm. water, range 15 to 60 versus 8, range 4 to 21). Compliance was significantly lower in group 2 than in group 1 (p <0.0005). Analysis of detrusor voiding pressure at maximum flow was not significantly different in the 2 groups. We noted detrusor under activity in 1 group 1 and 2 group 2 cases. In these patients post-void residual urine volume was 8% to 66% of cystometric bladder capacity. However, only 1 of these 3 patients who required augmentation cystoplasty needed intermittent catheterization. Urodynamic patterns of outflow obstruction developed in 1 patient in each group, including urethral stricture and bladder neck obstruction. At followup we observed no difference in renal function impairment in the 2 groups. CONCLUSIONS: Our retrospective study of rapid filling cystometry suggests that primary valve ablation for posterior urethral valves is associated with a better bladder function outcome than that in patients treated with vesicostomy and delayed valve ablation. Therefore, although cutaneous vesicostomy may be performed as initial management of posterior urethral valves, primary valve ablation is the most effective surgical option in these cases.

Adolescent↗
PubMed1998

Urethral duplication in children: surgical treatment and results.

PURPOSE: Urethral duplication is a rare congenital anomaly. We report the clinical presentation, imaging findings and surgical treatment in 7 boys with incomplete sagittal duplication of the urethra. MATERIALS AND METHODS: Duplication involved hypospadias in 5 cases (group 1) and a bifid urethra with an accessory preanal tract (Y duplication) in 2 (group 2). Group 1 was treated with 1-stage urethroplasty, including marsupialization of the dorsal orthotopic urethra, ventral-to-dorsal urethrourethrostomy and penile island flap onlay repair to cover the open dorsal urethra. In contrast, group 2 was treated with 2-stage urethral reconstruction with detachment and mobilization of the accessory preanal branch in association with a scrotal tubed neourethra followed by urethroplasty, as in group 1. In all cases the dorsal penile urethra was located between the corpora cavernosa and surrounded by the tunica albuginea. RESULTS: A urethrocutaneous fistula developed in 1 of the 5 group 1 patients. In group 2, 1 patient had recurrent penoscrotal meatal stenosis after the 1-stage procedure and 1 had a urethral diverticulum with calculi at the scrotal tubed neourethra 7 years after urethral reconstruction. Six of the 7 patients now void spontaneously through a meatus located normally at the tip of the glans. The remaining patient with a neurogenic bladder is on intermittent catheterization via appendicovesicostomy due to difficult catheterization of the irregular and sensitive neourethra. CONCLUSIONS: While the ideal surgical management of urethral duplication anomalies remains uncertain, we used a combination of surgical techniques to correct this severe malformation.

Child↗
PubMed1998

Monosymptomatic primary enuresis: differences between patients responding or not responding to oral desmopressin.

OBJECTIVES: To evaluate the 24-h diuresis, urinary osmolality, plasma arginine vasopressin (AVP) and urinary prostaglandin E2 (PGE2) before and during desmopressin treatment in patients with monosymptomatic primary enuresis (MPE), and to investigate the possible depressor effect of desmopressin on the detrusor in such patients with urodynamically confirmed bladder instability. PATIENTS AND METHODS: Seven healthy children (control group) and 11 consecutive patients with MPE (mean age 10.4 years, range 7-15) were assessed using laboratory tests, renal and bladder ultrasonography, and video-urodynamic investigations. A 24-h inpatient assessment with a controlled water intake of 20 mL/kg per day included determinations of diuresis, urinary osmolality, AVP and PGE2 in both normal children and those with MPE. After 30 days of treatment at optimal doses of desmopressin, all children were hospitalized and re-evaluated during desmopressin treatment; all completed 3 months of treatment at optimal doses. At the end of this period, patients whose symptoms improved by > or = 80% were defined as 'responders' while those in whom they did not were defined as 'non-responders'. RESULTS: After treatment, six of the 11 patients with MPE were 'responders' and five 'non-responders'. Urodynamic evaluation showed bladder instability in seven of the 11 patients with MPE but in those with bladder dysfunction, urodynamic studies carried out during desmopressin treatment showed no changes in detrusor activity. There were significant differences in the morning values of AVP between normal children and responders (P < 0.03), and between responders and non-responders (P < 0.02); none of the non-responders had AVP levels of < 2.5 pg/mL, while none of the responders exceeded this value. At midnight, responders had the lowest mean AVP and non-responders the highest; this correlated with the highest PGE2 value in the nonresponders at 00.00-08.00 hours. Non-responders had an overnight mean PGE2 level greater than that in normal subjects or responders. CONCLUSIONS: Polyuria occurred in all patients with MPE, independently of the response to desmopressin. Responders had the lowest AVP values over the 24 h; the morning AVP levels differentiated normal subjects from enuretic patients and responders from non-responders. In patients with MPE, clinically undetected bladder instability was unrelated to the results of treatment and there were no urodynamic changes during desmopressin treatment. The differences between enuretic patients suggested a different aetiology of MPE, probably related to an increase in PGE2 concentration and an antagonistic mechanism of action of AVP or desmopressin.

Administration, Oral↗
PubMed1998

Primary enuresis: a urodynamic evaluation.

OBJECTIVE: To assess urodynamic and clinical data in patients with primary enuresis for potential prognostic indicators of detrusor instability. PATIENTS AND METHODS: The records of 33 patients (mean age 8.8 years, range 5-14) with monosymptomatic primary enuresis (MPE, bedwetting as the sole symptom) and 47 patients (mean age 7.1 years, range 5-12) with complicated primary enuresis (CPE, bedwetting associated with diurnal urinary loss, squatting and urge incontinence) were reviewed. The children underwent urodynamic studies to detect detrusor instability and the prevalence was compared with the type of enuresis. RESULTS: Of 33 patients with MPE, 17 (49%) showed either typical unstable detrusor contractions (16) or low-compliance bladders (one); in the remaining 16 patients, filling cystometry was normal and micturition was normal in all. Of the 47 patients with CPE, 35 (79%) showed detrusor instability and two decreased bladder compliance; the remaining 10 had stable bladders and micturition was also normal in all patients. CONCLUSION: The type of primary enuresis and the maximum cystometric bladder capacity were good indicators of bladder dysfunction.

Adolescent↗
PubMed1997

Immediate management of posterior urethral disruptions due to pelvic fracture: therapeutic alternatives.

PURPOSE: We retrospectively reviewed the results of 3 types of initial management of pelvic fracture urethral disruption in children. MATERIALS AND METHODS: From 1980 to 1994, 35 boys 2 to 15 years old (mean age 8.1) with prostatomembranous urethral disruption were treated, including 17 who also had associated injuries. Immediate treatment included suprapubic cystostomy and delayed urethroplasty in 19 patients (group 1), urethral catheter alignment without traction and concomitant suprapubic cystostomy in 10 (group 2), and primary retropubic anastomotic urethroplasty in 6 (group 3). RESULTS: In all patients in groups 1 and 2 severe urethral obliteration developed. Four group 3 patients (66%) had a stricture at the site of anastomotic repair. After delayed urethroplasty 16 group 1 (84%) and all 10 group 2 patients were continent. However, only 3 group 3 patients (50%) achieved continence. Retrospectively associated bladder neck injury occurred in 5 of the 6 incontinent boys. Erections were observed before and after treatment in all but 3 children. Unstable pelvic ring fractures (type IV) comprised 28% of all pelvic fractures with a high rate of associated injuries. CONCLUSIONS: As described, urethral alignment was not beneficial for avoiding urethral obliteration. Therefore we recommend suprapublic cystostomy as the only form of initial treatment in these cases. Urinary incontinence seems more likely related to associated bladder neck rupture and the severity of pelvic fracture rather than to initial treatment or delayed urethral repair. Consequently, when associated bladder neck injury is present, we advocate immediate surgical repair.

Adolescent↗
PubMed1994

Hormonal parameters and testicular volume in children and adolescents with unilateral varicocele: preoperative and postoperative findings.

Preoperative and postoperative testicular volume, serum testosterone, follicle-stimulating hormone and luteinizing hormone were determined in 25 patients 8 to 19 years old (mean age 13.2 +/- 1.63) with grades 2 and 3 unilateral varicocele. Testicular growth arrest was considered significant when volume loss was greater than 2 ml. in the ipsilateral testis compared to the contralateral side. Baseline serum testosterone, follicle-stimulating hormone and luteinizing hormone as well as post-gonadotropin releasing hormone stimulation were determined preoperatively and at 4 to 6 months postoperatively. Data are presented as mean plus or minus standard deviation. Results showed an increase in serum testosterone in Tanner's stages 1 (p < 0.028) and 2 to 3 (p < 0.008). No differences were recorded in basal luteinizing hormone and follicle-stimulating hormone, as well as maximal follicle-stimulating hormone levels before and after surgery. A decrease of maximal luteinizing hormone response to gonadotropin releasing hormone test was noted postoperatively in pubertal stages 4 to 5, when compared to preoperative values. Postoperative ipsilateral testicular volume increased in all Tanner stages (p < 0.045, p < 0.008 and p < 0.012, respectively). Our observations suggest that varicocele may be initially responsible for interstitial dysfunction with preservation of germinal function and unilateral testicular growth arrest, however reversible, after pubertal surgical correction. This study supports previous reports suggesting that varicocelectomy in children who show anatomic and functional changes is advisable.

Adolescent↗
PubMed1988

Small kidney associated with primary vesicoureteral reflux in children. A pathological overhaul.

In this series two quite distinct pathological entities accounted for the small, often deformed, kidney found over a severe primary ureterovesical reflux. One of them is due to dysplastic abnormal metanephric differentiation, and the other is a segmental tubular atrophy with glomerular metamorphosis. In our material there is no evidence to support an inflammatory pathogenesis in these conditions. An abnormal excess vascularization is explained by an arteriovenous fistula present in both. Proper identification of the pathology underlying such cases will assist further studies on the natural history of these two diverse malformations.

Child↗
PubMed1985

Ultrastructural characteristics of collagen tissue in normal and congenitally dilated ureter.

Scanning electron microscopy is a useful method to study the organization distribution and orientation of the collagen fibers in the ureteral wall. Different collagen structural patterns have been observed in normal ureter, primary obstructive megaureter and refluxing megaureter. A pathogenic hypothesis is advanced based on the different functional characteristics of each one of these entities. Collagenous proliferation in primary obstructive megaureter and refluxing megaureter could be related to ureteric smooth muscle cell disfunction.

Adult↗