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Biomedical subjects

S B Bauer

Publications and source records attributed to S B Bauer.

At least 55 records · Page 3Linked to original sources
PubMed1996

Ten-year experience with the artificial urinary sphincter in children.

PURPOSE: To assess the efficacy of the artificial urinary sphincter survival and continence were first evaluated 5 years ago. We now evaluated the effects of the artificial urinary sphincter more than a decade after implantation. MATERIALS AND METHODS: Before 1985 an artificial urinary sphincter was implanted in 22 male and 14 female consecutive patients 4 to 30 years old (median age 12). In addition, between 1985 and 1990, 18 other children underwent artificial urinary sphincter implantation. Results of both series were compared. RESULTS: Of the 25 sphincters in the original series that were functioning after 5 years 1 was removed and 2 patients were lost to followup, resulting in 22 functioning implants (61% of the patients). Mean survival time of the prostheses was 12.1 years and average followup for functioning sphincters was 13.7 years. There was no statistically significant difference in artificial urinary sphincter survival between the original group at 5 years and the second group treated after 1985. Of the patients in both groups with sphincters in place 32 of 39 (82%) were dry. Augmentation cystoplasty was performed in 9 of 18 patients (50%) in the second series (5 preoperatively and 4 postoperatively) compared to 10 of 36 (28%) in the original series at 5 years (3 preoperatively and 7 postoperatively). Renal failure developed in 6 patients from both series. CONCLUSIONS: The artificial urinary sphincter is a durable long-term solution for children with intractable incontinence. Long-term surveillance of the urinary tract is mandatory because of the potential for renal failure in patients who have bladder hypertonicity after placement of the device.

Adolescent↗
PubMed1996

Functional bladder capacity measured during radionuclide cystography in children.

PURPOSE: To estimate functional bladder capacity (FBC) during direct radionuclide cystography and to assess the relationship between vesicoureteral reflux and FBC. MATERIALS AND METHODS: By using 5,165 direct radionuclide cystograms in patients aged newborn to 14 years, linear and nonlinear models were fit to estimate FBC from age. Analysis was performed on girls and boys separately. In a subgroup, height and weight were evaluated as predictors of FBC. Linear models were used to assess differences in predicted FBC according to sex and reflux status. RESULTS: The relationship between FBC and age is best described by a nonlinear power function. Percentiles derived from this model are close to the empiric percentiles of FBC. When controlling for age, girls and patients with reflux had larger bladder capacities (P < .01). Height and weight did not improve FBC prediction accuracy. CONCLUSION: FBC follows a curve with increasing age. The nonlinear relationship between FBC and age appears to be consistent with maturation in infants and children.

Adolescent↗
PubMed1996

Bladder stimulation therapy improves bladder compliance: results from a multi-institutional trial.

PURPOSE: We examined data from multiple institutions to determine whether intravesical bladder stimulation therapy is effective in improving bladder compliance by increasing bladder capacity and lowering bladder storage pressures. MATERIALS AND METHODS: The charts of 568 patients from 11 institutions were evaluated. Of the 568 patients 335 had adequate and accurate pretreatment and posttreatment urodynamic studies, and were included in this study. A total of 155 patients was from Children's Memorial Hospital, while the remaining 180 were from 10 other institutions. Bladder capacity and bladder capacity pressure were determined for each patient before and after therapy. RESULTS: Overall, 53% of patients had increased bladder capacity of 20% or greater after treatment (average increase 105 cc), which represents a 63% increase from pretreatment values. This increase occurred in an average of 1.9 years. Further analysis of this subset of patients revealed that in 90% intravesical storage pressures were decreased or maintained within a safe range (less than 40 cm. water). Evaluation of patients who did not respond to bladder stimulation with a 20% or greater increase in bladder capacity revealed that they had nearly normal bladder capacity before therapy. When the data on bladder capacity and bladder capacity pressure from Children's Memorial Hospital were compared to results from the 10 other institutions, there were no appreciable differences. CONCLUSIONS: Bladder stimulation is effective in increasing bladder capacity without significantly elevating storage pressure in a majority of patients. We conclude that this technique is safe and effective in improving bladder compliance, and that it is reproducible elsewhere.

Adolescent↗
PubMed1996

Reconstructive options in genitourinary rhabdomyosarcoma.

PURPOSE: We attempted to develop a rational and consistent scheme for surgical reconstruction in patients with genitourinary rhabdomyosarcoma. MATERIALS AND METHODS: We reviewed the records of 35 patients with resectable genitourinary rhabdomyosarcoma treated from 1970 to 1993. RESULTS: Primary sites included bladder in 11 cases, prostate in 13, vagina/uterus in 9 and pelvic tumors of uncertain origin in 2. A total of 33 patients underwent surgery, including partial and radical cystectomy in 17 (bowel conduit diversion in 10, continent urinary diversion in 6 and ureterosigmoidostomy in 1). Overall 30 of the 33 surgical patients are free of disease 4 months to 24 years after diagnosis. CONCLUSIONS: A nonrefluxing colon conduit is appropriate at cystectomy. Continent diversion fashioned from the original conduit may be planned as the patient achieves a durable disease-free status.

Adolescent↗
PubMed1996

Natural history of vesicoureteral reflux in siblings.

PURPOSE: We attempted to assess the natural course of vesicoureteral reflux after it was detected in asymptomatic siblings of children with reflux, and to determine predictors of and time to resolution. MATERIALS AND METHODS: We reviewed the records and radionuclide cystograms of 76 girls and 32 boys 2 weeks to 103 months old (mean age 21 months) with vesicoureteral reflux detected in a sibling screening program. Predictors were determined using logistic regression and survival analysis. RESULTS: Vesicoureteral reflux resolved in 52.8% of cases at a mean followup of 18.5 months. Yearly resolution rates exceeded 28%. Predictors of the likelihood of resolution were not identified. At diagnosis unilateral reflux and mild reflux were independent and univariate predictors, respectively, of more rapid resolution. CONCLUSIONS: By showing that spontaneous resolution is likely for children with vesicoureteral reflux detected in a sibling screening program, this study supports nonsurgical management with annual imaging evaluation.

Child↗
PubMed1995

Electrophysiological and urodynamic studies to monitor surgical outcome in children with tethered spinal cords.

Children with myelodysplasia often develop tethering of their spinal cord within 2-3 years after correction of their initial birth defect, leading to either neurological or urological dysfunction. Surveillance of these children includes electrophysiologic/urodynamic (EMG/UDS) studies to monitor improvement or deterioration of their neurological function. We reviewed 39 patients who underwent surgical untethering from 1979 to 1994 to determine whether postoperative EMG/UDS studies were useful in assessing outcome after surgery. All patients had a complete neurologic examination and an EMG/UDS prior to and 3 months after surgery. Twenty patients (51%) showed improvement in their EMG/UDS study after untethering, 15 (39%) demonstrated no significant change, and 4 (10%) showed deterioration. Improvement consisted of either return of previously absent motor units, return of sacral reflexes, or improved bladder dynamics. In a further 3 patients, subsequent deterioration on serial postoperative EMG/UDS testing was the first indication of recurrent tethering. We conclude that serial EMG/UDS evaluation in patients at risk for tethering of the spinal cord may serve as a useful adjunct to close clinical observation.

Child↗
PubMed1995

The effects of delayed diagnosis and treatment in patients with an occult spinal dysraphism.

From 1987 to 1993, 21 older individuals presented for the first time with signs and symptoms that eventually led to the diagnosis of occult spinal dysraphism. Assessment consisted of a neurological examination, urodynamic studies preoperatively and postoperatively, and spinal cord imaging. Of 21 patients 18 had an abnormal neurological examination, whereas only 15 had an abnormal urodynamic study, as judged by sphincter electromyography. Radiological imaging showed that 9 patients had a tethered cord alone, 4 each had lipomeningocele and lipoma, 2 had a bony spine abnormality and 1 each had thoracic meningocele and diastematomyelia. Of the 21 patients 19 underwent spinal surgery. Postoperatively, the neurological examination improved in 1 case (5%) and remained unchanged in 18 (95%), while urodynamic findings improved in 3 (16%), were unchanged in 11 (68%) and worsened in 5 (26%). Six patients had progressive deterioration and required secondary spinal surgery, which helped only 2 (33%). These observations confirm that older children and adults with occult spinal dysraphism are more likely to present with irreversible urological and neurological findings than younger children, and so it is imperative that a diagnosis be made and treatment be instituted as early as possible.

Adult↗
PubMed1995

Retained sacral function in children with high level myelodysplasia.

To assess the preservation of sacral function despite denervation higher on the spinal cord in children with myelodysplasia, we examined 151 myelomeningocele patients presenting for urodynamic evaluation from 1980 to 1992 with a lesion at L3 or above on neurological examination. Of the 151 patients 70 (46%) had denervation of the external sphincter on initial evaluation and 81 (54%) had sacral sparing, that is normal or near normal electrical potentials of the external urethral sphincter and/or retained reflexic bladder activity regardless of the presence or absence of sacral reflexes. Of the 81 patients with sacral sparing 57 (70%) had detrusor-sphincter dyssynergia and 21 had synergy or denervation of the sphincter in association with retained detrusor reflexia. Whereas only 18% of children age 1 year or younger with retained sacral function had upper urinary tract deterioration on initial radiological studies (manifested by reflux or hydronephrosis), 57% had deterioration when evaluated after age 1 year. None of the patients without retained sacral function had evidence of upper urinary tract damage at younger than 1 year but 28% of those studied beyond age 1 year had changes. Patients with flaccid lower extremities can retain sacral function, which puts the upper urinary tract at risk of deterioration. Our results show that this risk increases with time.

Adolescent↗
PubMed1995

Comparative urodynamics of appendiceal and ureteral Mitrofanoff conduits in children.

We report the cystometric and conduit pressure profilometric findings of 20 children for whom the Mitrofanoff principle was applied to the construction of 21 continent catheterizable urinary conduits. Mitrofanoff conduits were fashioned from ureter in 10 cases, appendix in 8, ileum in 1, stomach in 1 and a combination appendix and ureter in 1. Conduit pressure profiles showed that functional profile length correlated strongly with the static profile maximal Mitrofanoff closure pressure (p = 0.04) and dynamic profile maximal Mitrofanoff closure pressure (p = 0.02). There was a statistically significant difference between clinical continence rates for children above and below the functional profile length threshold of 2.0 cm. (p = 0.05). The zone of continence corresponded to the region of the conduit intramural tunnel. Only 2 of 21 conduits were incontinent but both were constructed with ureters implanted into bowel reservoirs. Compared to appendiceal conduits, ureteral conduits had a lower functional profile length (p < 0.01) and static profile maximal Mitrofanoff closure pressure (p < 0.01), indicating a possible advantage to the use of the appendix.

Adolescent↗
PubMed1995

Urodynamic findings in children with spinal cord ischemia.

PURPOSE: We identified urodynamic patterns of lower urinary tract dysfunction in children after anterior spinal artery injury. MATERIALS AND METHODS: Between 1981 and 1993, 6 boys and 1 girl in whom ischemic spinal cord injuries developed after umbilical artery catheterization (4), cardiovascular surgery (2) and spontaneous bleeding from an arteriovenous fistula (1) were evaluated radiologically, neurologically and urodynamically. RESULTS: Neurological assessment revealed a motor level from T8 to S1 in all 7 children, whereas only 3 had sensory denervation ranging from T8 to L4. Urodynamic studies demonstrated a mixed upper and lower motor neuron pattern in 3 patients, a lower motor neuron lesion only in 3 and a pure upper motor neuron deficit in 1. Treatment consisted of oxybutynin in 5 cases, Credé voiding in 1 and close observation in 1. All children are dry and kidney function has remained stable. CONCLUSIONS: Spinal cord ischemia in children is a rare condition that can arise from a variety of causes, the most common of which are embolism from umbilical artery catheterization and surgical repair of a patent ductus arteriosus. The urodynamic patterns are variable but characteristically they can be upper or lower motor neuron in nature. Precise testing will lead to appropriate therapy to prevent upper urinary tract disease and minimize incontinence.

Child↗
PubMed1995

The long-term urological response of neonates with myelodysplasia treated proactively with intermittent catheterization and anticholinergic therapy.

PURPOSE: Urinary tract management in children with myelodysplasia is controversial. Some advocate observation alone, while others believe that the prophylactic institution of intermittent catheterization and anticholinergic therapy may help to prevent deterioration. MATERIALS AND METHODS: A nonrandomized prospective study was instituted to compare the urological outcomes of a cohort of children who were at risk for urological deterioration on the basis of bladder-sphincter dyssynergia and/or high filling or voiding pressures. Those at risk were observed until deterioration occurred, or were placed on prophylactic intermittent catheterization with or without anticholinergic medication. RESULTS: Of 44 children at risk 35 followed by observation alone had urinary tract deterioration, whereas only 3 of 20 at risk treated with prophylactic intermittent catheterization had deterioration with time. CONCLUSIONS: Proactive bladder treatment significantly reduced the incidence of upper urinary tract deterioration and need for surgical intervention.

Cholinergic Antagonists↗
PubMed1994

Meatal based hypospadias repair with the use of a dorsal subcutaneous flap to prevent urethrocutaneous fistula.

A technique using a dorsal dartos subcutaneous flap to wrap the neourethra after hypospadias repair is described. This method was used in a series of 204 meatal based repairs. Catheter drainage or diversion was not performed in any nontoilet trained child. The procedure was done on an ambulatory or 1-night hospitalization basis. No patient had a urethrocutaneous fistula. The additional covering of the neourethra with the dorsal subcutaneous flap appears to be excellent for avoiding the development of urethrocutaneous fistulas in patients with distal hypospadias.

Adolescent↗
PubMed1994

Management of severe hypospadias with a 2-stage repair.

From 1986 to 1993 we treated 1,437 children with hypospadias of whom 58 had scrotal or perineal hypospadias with severe chordee and a small phallus. These patients underwent a 2-stage surgical repair. The first stage of the procedure included correction of the chordee and advancement of preputial flaps ventrally and distally to the superior aspect of the glans. After 6 to 12 months the second stage of the procedure was performed using the previously transferred preputial skin to reconstruct the glans and urethra. A second layer of subcutaneous tissue or tunica vaginalis was used in several instances. A penile nerve block and a transparent biomembrane dressing (Tegaderm) allowed for early postoperative mobilization. Excellent functional and cosmetic results were achieved. There is a subset of patients with severe proximal hypospadias, chordee and a small phallus who may benefit best from a 2-stage procedure. In these children a 2-stage repair allows for a better cosmetic appearance and a lower complication rate than a 1-stage repair with a free or vascularized graft.

Child↗
PubMed1994

Abnormal detrusor function precipitating hydronephrosis identified by extended voiding cystometry.

Extended voiding cystometry was performed to elucidate the true detrusor function in a patient originally misdiagnosed during standard fill cystometry. This methodology allows for observation of an extended period of bladder activity and eliminates the artifacts of classical fill cystometry, which are detrusor instability and noncompliance. A chronically elevated intravesical pressure between contractions (inter-contraction pressure) representing high pressure residual urine, as well as frequent, high amplitude, long duration detrusor contractions during the storage phase and a large post-void residual urine volume were documented. These urodynamic abnormalities are known to precipitate hydroureteronephrosis in the absence of vesicoureteral reflux.

Adult↗
PubMed1994

Laparoscopic evaluation of the nonpalpable tests: a prospective assessment of accuracy.

To assess diagnostic accuracy, laparoscopy and surgical exploration were prospectively performed in 104 children with 126 nonpalpable testes. Laparoscopic localization of the testis was correct in 90% (114 of 126 testes) and was nondiagnostic in 8% largely due to preperitoneal insufflation. No surgical complications occurred. Using the criteria of blind-ending vas deferens and spermatic vessels as diagnostic of an intra-abdominal vanishing testis, the accuracy of diagnosis was 100% but the inability to identify either vas or vessels was associated with intra-abdominal testes in 2 of 3 cases. Identification of canalicular vas deferens and spermatic vessels was associated with testes in 36 of 75 cases (48%). Bilateral nonpalpable testes were significantly less likely to have an absent testes (5%) than a unilateral nonpalpable testis (59%), suggesting the possibility of different pathophysiological mechanisms in those entities. Diagnosis and surgical management of nonpalpable testes were directly impacted by laparoscopy in 42 of 117 testes (36%) by identifying intra-abdominal vanishing testis, the location of an intra-abdominal testes or the need for retroperitoneal exploration when vas deferens and spermatic vessels were not found. Accurate knowledge of testis location in 97% of the testes facilitated development of an appropriate surgical strategy (that is laparoscopic/laparoscopic assisted versus open procedure).

Adolescent↗
PubMed1994

The use of intravesical oxybutynin chloride in patients with detrusor hypertonicity and detrusor hyperreflexia.

Intravesical oxybutynin chloride was administered to 11 children and 7 adults with upper motor neuron bladder dysfunction who were refractory to oral use or who had intolerable side effects from the medication. This therapy was combined with clean intermittent catheterization to ensure complete emptying of the bladder. Five children and 5 adults discontinued therapy due to side effects or the inconvenience of the procedure. The remaining 6 children and 2 adults continue the medication successfully and have shown on followup urodynamic studies that bladder volumes are greater and intravesical pressures are lower than before medication. Intravesical oxybutynin chloride seems to be an effective modality to treat some of these patients but it is not without significant side effects.

Administration, Intravesical↗
PubMed1993

The neurosurgical implications of continuous neurourological surveillance of children with myelodysplasia.

Between 1979 and 1990, 148 newborns with myelodysplasia were followed with serial urodynamic studies and neurological assessment. Of the patients 59 (40%) exhibited changes in neurological status by age 5 years, of whom 28 (19%) showed signs of deterioration. Most changes occurred before age 2 years. A total of 22 children underwent repeat neurosurgical exploration because of a change in urethral sphincter innervation (17), deterioration of function of the lower extremities (3), or changes on computerized tomography or magnetic resonance imaging (2). Postoperative urodynamic evaluation demonstrated improvement in 11 children, stabilization in 9 and further deterioration in 2. The earlier that a change was detected and secondary surgery was performed, the better the outcome. These findings indicate that the neurological lesion in myelodysplasia is a dynamic disease process requiring continuous neurological, orthopedic and urodynamic surveillance. Early identification and prompt neurosurgical reexploration seem to arrest and even reverse the neurological deterioration that takes place in a substantial number of these children.

Child, Preschool↗