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Biomedical subjects

P F Austin

Publications and source records attributed to P F Austin.

16 recordsLinked to original sources
PubMed2001

Advantages of rectus fascial slings for urinary incontinence in children with neuropathic bladders.

PURPOSE: Many surgical procedures to improve outlet resistance in children with neuropathic bladders are obstructive and increase the detrusor leak point pressure. In contrast, fascial slings are designed to achieve continence by increasing the Valsalva or stress leak point pressure without altering the detrusor leak point pressure. We evaluate the effectiveness of fascial slings in achieving continence in pediatric patients with neuropathic bladder. MATERIALS AND METHODS: From October 1994 until February 1999, 10 females and 8 males with neuropathic bladder secondary to myelodysplasia or traumatic spinal cord injury underwent fascial sling procedures. Mean patient age was 14 years (range 8 to 18) and all were incontinent despite aggressive medical management. Urodynamic evaluation was performed preoperatively and postoperatively. Specific urodynamic measurements included detrusor leak point pressure, stress leak point pressure and detrusor compliance. Compliance was only compared in the 12 nonaugmented cases. RESULTS: With a mean followup of 21.2 months (range 6 to 57), preoperative and postoperative urodynamics revealed little change in mean detrusor leak point pressure (23.2 versus 23.22 cm. H2O) but a substantial increase in mean stress leak point pressure (41.6 versus 64.5 cm. H2O). Mean compliance was unchanged in the nonaugmented group (22.00 versus 26.78 ml/cm. H2O). Four patients (22.22%) remained wet after surgery, of whom 2 were successfully treated with a repeat sling procedure and 1 with collagen injection for an overall continence rate of 94.44%. CONCLUSIONS: Fascial slings can be effectively used in pediatric patients for neuropathic incontinence. Furthermore, stress urinary incontinence is corrected by increasing the Valsalva or stress leak point pressure with preservation of the detrusor leak point pressure. Preservation of detrusor leak point pressure is particularly advantageous because other forms of bladder outlet procedures achieve continence at the expense of increasing detrusor pressures, thus placing the upper tracts at risk for damage.

Adolescent↗
PubMed2001

Symptomatic ureteropelvic junction obstruction in children in the era of prenatal sonography-is there a higher incidence of crossing vessels?

OBJECTIVES: To determine whether prenatal sonography and early detection and correction of ureteropelvic junction obstruction (UPJO) has changed the incidence of crossing vessels as the etiology of obstruction in older children presenting with symptomatic UPJO. METHODS: We reviewed the medical records of all children and adolescents who underwent pyeloplasty for symptomatic UPJO between 1986 and 1999, during the era of widespread use of prenatal sonography. Operative notes were used to determine which patients had obstruction due to lower pole crossing vessels. RESULTS: Thirty-eight patients were identified who underwent pyeloplasty for symptomatic UPJO. Lower pole vessels were identified in 22 (58%) of 38 patients (P <0.0001 compared with historical controls). All patients underwent dismembered pyeloplasty and remained asymptomatic after surgery, with renal scans demonstrating excellent drainage and preservation of function. CONCLUSIONS: Prenatal ultrasonography has increased the incidence of crossing vessels as the etiology of UPJO in young children and adolescents presenting with symptomatic UPJO compared with the historical incidence of 11% to 15%. This finding may impact treatment recommendations with respect to endourologic management of the obstruction in this patient population. Currently, we recommend open dismembered pyeloplasty for young children and adolescents presenting with symptomatic UPJO.

Child↗
PubMed2001

Multi-institutional experience with the gastrointestinal composite reservoir.

PURPOSE: We evaluated multi-institutional experience with the gastrointestinal composite reservoir in patients with metabolic acidosis, the short bowel syndrome, severe pelvic radiation and/or renal insufficiency. MATERIALS AND METHODS: At 4 institutions 33 patients underwent construction of a gastrointestinal composite reservoir, including 19 with the short bowel syndrome, 13 with metabolic acidosis and 7 who also had renal insufficiency. A total of 16 patients underwent conversion of a previous diversion and the remaining 17 received new urinary diversion. Charts were reviewed for the metabolic impact of the gastrointestinal reservoir as well as any long-term sequelae. RESULTS: At a mean followup of 54 months there was a significant (p < or =0.05) improvement in mean preoperative and postoperative serum chloride (106 versus 102 mEq./l.), serum bicarbonate (23.3 versus 25 mEq./l.) and serum pH (7.36 versus 7.4). Mean serum creatinine did not significantly differ during followup in patients with normal renal function or renal insufficiency. Complications were not different than those of standard intestinal or gastric reservoirs. CONCLUSIONS: The gastrointestinal reservoir has provided an excellent metabolic balance in a large series of compromised patients with few side effects. We believe that the gastrointestinal composite reservoir represents the urinary diversion of choice when standard intestinal urinary reservoirs cannot be created in the setting of metabolic acidosis, the short bowel syndrome and severe pelvic radiation. However, the value of the gastrointestinal composite in the setting of renal insufficiency remains undetermined.

Acidosis↗
PubMed2000

Nephrostomy tube drainage with pyeloplasty: is it necessarily a bad choice?

PURPOSE: Despite continued controversy regarding the optimal method of urinary diversion after dismembered pyeloplasty in children, we have treated the majority of our patients with postoperative nephrostomy tubes and no stents. We report our experience. MATERIALS AND METHODS: The records of all patients who underwent surgery for ureteropelvic junction obstruction from August 1985 to October 1998 and were treated only with a nephrostomy tube after pyeloplasty were reviewed for hospital course, complications and postoperative followup. All patients had a perinephric Penrose drain as well as a Foley catheter placed for bladder drainage. RESULTS: A total of 137 pyeloplasties were performed in 132 patients, including 5 with bilateral ureteropelvic junction obstruction, using only nephrostomy tube drainage with an average followup of 2.1 years. Initial nephrostograms demonstrated good drainage across the repair with no extravasation in 91% of patients. Subsequent nephrostograms revealed a widely patent anastomosis in the remaining cases. No patient had postoperative obstruction, or required secondary pyeloplasty or nephrectomy. Urinary tract infection developed in 2 patients (1.5%). Mean hospitalization was 4.4 days. There was a significant difference in length of stay in the last 5 years compared to that in previous years (3.4 versus 5.8 days, p <0.05) and hospital stay continues to decrease. CONCLUSIONS: Use of only a nephrostomy tube after pyeloplasty resulted in few complications and an open anastomosis in 100% of cases. Nephrostomy drainage not only serves as a protective mechanism, but also allows easy access for radiographic studies before removal of the tube. In addition, nephrostomy tube drainage does not prolong hospitalization and the tube may be easily removed on an outpatient basis without further anesthesia.

Child↗
PubMed1999

alpha-Adrenergic blockade in children with neuropathic and nonneuropathic voiding dysfunction.

PURPOSE: Inadequate bladder emptying is a common urinary dysfunction in children. The role of alpha-blockers for managing bladder outlet obstruction remains relatively unexplored in children. Because of the well established impact of alpha-blocker therapy in men, we investigated its use for treating inadequate bladder emptying in the pediatric population. MATERIALS AND METHODS: We treated 17 children 3 to 15 years old with documented poor bladder emptying of various etiologies, including dysfunctional voiding, the Hinman syndrome, the lazy bladder syndrome, posterior urethral valves, myelomeningocele and the prune-belly syndrome, using the alpha-1 adrenergic receptor antagonist, doxazosin. The initial dose of 0.5 to 1.0 mg. nightly was increased according to patient response and as tolerated. Patients were followed weekly to monthly by symptomatic history, and urine flow and/or post-void residual urine volume measurement. Two patients with neurogenic bladder were also followed with cystometrography and leak point pressure determination. RESULTS: Bladder symptomatology and/or emptying improved in 14 patients (82%). Ten patients had decreased post-void residual urine during treatment and in 3 uroflowmetry showed increased maximum flow. Two patients with neuropathic bladder secondary to myelomeningocele had decreased leak point pressure on alpha-blocker therapy and in 2 with a history of posterior urethral valves new onset bilateral hydronephrosis completely resolved. Only 1 patient had mild postural hypotension, which resolved with dose reduction. CONCLUSIONS: Selective alpha-blocker therapy seems to be well tolerated in children and appears effective for improving bladder emptying in various pediatric voiding disorders at short-term followup. Long-term followup and further investigation are warranted to validate the potential role of alpha-blocker therapy in pediatric urinary dysfunction.

Adolescent↗
PubMed1999

The gastrointestinal composite urinary reservoir in patients with myelomeningocele and exstrophy: long-term metabolic followup.

PURPOSE: We investigated the long-term metabolic effects of gastrointestinal composite urinary reservoirs in patients with myelomeningocele or exstrophy. MATERIALS AND METHODS: Seven patients with myelomeningocele or exstrophy who required complex urinary reconstruction in the setting of metabolic acidosis or the short bowel syndrome underwent construction of a gastrointestinal composite reservoir, including a staged and a single procedure in 3 and 4, respectively. Preoperatively and postoperatively serum electrolytes were measured, and urinalysis and urine cultures were performed in all patients. In 5 patients serum pH was compared preoperatively and postoperatively, and in all serum gastrin was measured postoperatively. RESULTS: At an average followup of 62 months (range 52 to 87) serum chloride and bicarbonate significantly normalized (p <0.05) in all 7 patients with bladder exstrophy or myelomeningocele. Serum pH also significantly normalized (p <0.05) in 5 patients at long-term followup. Serum gastrin and creatinine were normal and urinary pH fluctuated insignificantly throughout followup. None of the patients had urolithiasis or symptoms of the hematuria-dysuria syndrome. Periodic symptomatic urinary tract infections developed but none required chronic antibiotic therapy. CONCLUSIONS: Gastrointestinal composite urinary reservoirs appear to be beneficial for patients with myelomeningocele or exstrophy who have preexisting metabolic acidosis or the short bowel syndrome. Serum electrolyte neutrality is achieved during long-term followup. No patient had the hematuria-dysuria syndrome or urolithiasis.

Adult↗
PubMed1999

Evaluation of flap valve as an alternative continence mechanism in the Florida pouch.

OBJECTIVES: To evaluate urodynamic findings in a successful flap valve (FV) continence mechanism in association with a continent colonic urinary reservoir (Florida pouch) and to compare the urodynamic findings of the FV mechanism with the doubly plicated (PI) standard anti-incontinence segment in the same reservoir. METHODS: Thirteen patients who successfully received the Florida pouch between 1988 and 1996 agreed to undergo urodynamic evaluation as part of a pilot study. Eight patients had a PI continence mechanism and a mean time from surgery of 51 months; 5 had a FV continence mechanism and a mean time from surgery of 14 months. Enterocystometry was performed with a trans-stomal Bard triple channel 7F catheter. Volume and pressure at first desire to empty (VFDE, PFDE), as well as maximal enterocystometric capacity and pressure (VMEC, PMEC), were recorded. Maximal outlet pressure (MOP) was recorded using the catheter withdrawal technique. RESULTS: PI and FV groups demonstrated the following mean values respectively: VFDE, 692.7 and 403 mL; PFDE, 19.5 and 19.2 cm H2O; VMEC, 876.5 and 515 mL; PMEC, 25.9 and 24.6 cm H2O; MOP, 57.5 and 51.2 cm H2O (reservoir empty) and 50.5 and 52.6 cm H2O (reservoir full); and functional length of outlet, 24.3 and 24.6 cm. MOP measurement demonstrated greater variability in the PI than in the FV group. CONCLUSIONS: Urodynamic comparison of these mechanisms reveals that MOP measurement was closer to the mean among FV than PI patients. In addition, the mean VFDE (692.7 mL for PI versus 403 mL for FV, P < 0.05) and the mean VMEC (876.5 mL for PI versus 515 mL for FV, P < 0.05) were significantly less in the FV group. Lower VMEC and less variability in MOP indicate that continence may be more dependent on MOP in the FV mechanism. A longer follow-up time and a larger number of patients will be of assistance in clarifying these findings.

Humans↗
PubMed1999

Predictability of PSA failure in prostate cancer by computerized cytometric assessment of tumoral cell proliferation.

OBJECTIVES: To evaluate the relationship of DNA ploidy and cell proliferation (CP) with Gleason score (GS) and clinical outcome in prostate cancer. METHODS: Sixteen patients with benign prostatic hyperplasia (BPH) and 65 patients with prostate cancer classified by GS (four groups: 2 to 4, 5 to 6, 7, and 8 to 10) were studied. All patients with carcinoma underwent prostatectomy and were separated into prostate-specific antigen (PSA) failure and nonfailure groups (failure if PSA 0.1 ng/mL or more three times after surgery). Tumoral CP (Ki-67 inmunostaining and SG2M phase) and DNA ploidy were evaluated by computerized cytometry. RESULTS: BPH were diploid with low CP (8% SG2M cells or less). Carcinomas were either diploid with high CP (greater than 8% SG2M cells) or aneuploid. CP was significantly higher (P <0.001) in tumors with GS 7 or greater than in tumors with GS less than 7 (mean percent Ki-67 cells 18.3% versus 7.8%, respectively). PSA failure increased with GS (7.1% in GS 2 to 4, 21% in GS 5 to 6, 28.6% in GS 7, and 50% in GS 8 to 10), as well as with aneuploidy (18.5% in diploid tumors versus 72.7% in aneuploid tumors). Those experiencing PSA failure had significantly higher (P <0.001) CP than those not failing (mean percent Ki-67 cells 24% and mean percent SG2M 30.4% versus 8.7% and 13.5%, respectively). Cox regression analysis showed GS, DNA ploidy, Ki-67, and SG2M to each be univariately prognostic for time to PSA failure; however, Ki-67 and SG2M were more highly significant (P <0.0001 for both) than GS (P = 0.007) or DNA ploidy (P = 0.002). After adjusting for either SG2M or Ki-67 measures of CP, neither ploidy nor GS contained additional prognostic value. CONCLUSIONS: Tumor CP and DNA ploidy can be reliably determined in prostate cancer by computerized cytometry. On the basis of our preliminary results, CP correlates well with GS and predicts PSA failure better than DNA ploidy or GS.

Aged↗
PubMed1998

Prenatal bladder outlet obstruction secondary to ureterocele.

We present 2 cases of prenatal hydroureteronephrosis and bladder outlet obstruction due to an obstructing ureterocele. Both neonates were stabilized and managed with early endoscopic decompression. Neither infant demonstrated significant function in the kidney ipsilateral to the ureterocele either before or after ureterocele puncture. There have been few cases reported of prenatal bladder outlet obstruction due to a ureterocele. Our limited experience has been poor with regard to salvaging the affected upper tract. Future definitive management will be tailored as more of these cases are documented.

Female↗
PubMed1998

The prenatal diagnosis of cloacal exstrophy.

PURPOSE: We assess and clarify diagnostic features for making the prenatal diagnosis of cloacal exstrophy. MATERIALS AND METHODS: We evaluated 9 patients born with cloacal exstrophy at our institutions (2 prospectively and 7 retrospectively) for diagnostic features on prenatal ultrasound studies. We also thoroughly reviewed the literature on 13 previous prenatally diagnosed cloacal exstrophy cases. Diagnostic criteria were assessed by combining the findings in our patients and those in previous reports. RESULTS: Of the 22 patients with prenatal ultrasound studies and cloacal exstrophy whom we analyzed 1 of our 9 and 2 in the literature had a cloacal membrane that persisted at 22 weeks of gestation. Major ultrasound criteria for diagnosing cloacal exstrophy prenatally are nonvisualization of the bladder, a large midline infraumbilical anterior wall defect or cystic anterior wall structure (persistent cloacal membrane), omphalocele and lumbosacral anomalies. Seven less frequent or minor criteria include lower extremity defects, renal anomalies, ascites, widened pubic arches, a narrow thorax, hydrocephalus and 1 umbilical artery. CONCLUSIONS: We propose major and minor criteria to assist in the prenatal diagnosis of cloacal exstrophy. Despite these major and minor criteria the certainty of establishing a prenatal diagnosis remains challenging. Persistence of the cloacal membrane beyond the first trimester in 1 patient was an exception to the classic concept of cloacal exstrophy embryogenesis. An accurate prenatal diagnosis requires validation of these criteria by further correlation of prenatal and postnatal observations.

Cloaca↗
PubMed1998

Daytime functional bladder capacity as a predictor of response to desmopressin in monosymptomatic nocturnal enuresis.

OBJECTIVE: The objective of this study was to identify a cost-effective method of predicting a therapeutic response to desmopressin (DDAVP) by correlating daytime functional bladder capacity, age and urine osmolalities in patients with monosymptomatic nocturnal enuresis. MATERIALS AND METHODS: Thirty-five children out of 51 who initially presented to our institutions were included in the study. The remainder was excluded for lack of complete data. Constipation was actively addressed and was managed by administration of evening enemas for 3 consecutive days and dietary adjustment prior to initiating the study. Each micturition as measured throughout the day and the maximal daytime functional bladder capacity was determined as the largest void over a 2-day period. Urine samples were collected at home at 08:00, 16:00 and 22:00 (times that would best reflect the fluctuations in plasma vasopressin levels). Intranasal DDAVP was then administered, titrating the dose over a 2-week period. The initial dose was 10 micrograms and the dose was increased 10 micrograms every 3 days. RESULTS: The response to DDAVP was then evaluated and of the 35 children, 27 demonstrated a complete response to DDAVP (all at doses between 10 and 30 micrograms). These were then related to the possible predictive factors. There was a significant correlation between a high maximum daytime functional bladder capacity and response to DDAVP (p = 0.006). Similarly, age was also predictive of a good response to DDAVP treatment (p = 0.008). However, spot urine osmolalities were not predictive of a response to DDAVP (p > 0.1). CONCLUSIONS: Functional bladder capacity is a reliable predictor of response to desmopressin; children with larger capacities are more likely to exhibit a successful response. Older children have a better response rate than younger ones. Spot urine osmolality measured on specimens collected in the home setting is not predictive of response to desmopressin.

Administration, Intranasal↗
PubMed1997

Long-term metabolic advantages of a gastrointestinal composite urinary reservoir.

PURPOSE: We investigated the long-term metabolic impact of gastrointestinal composite reservoirs. MATERIALS AND METHODS: Nine patients underwent construction of a gastroileal (7) or gastrocolonic (2) reservoir for continent urinary diversion. Four cases of metabolic acidosis were converted from a preexisting conduit and the other 5 patients had diversion for either preexisting metabolic acidosis or the short bowel syndrome. All were reconstructed using a medium sized gastric segment (8 x 4 cm.) from the greater curvature of the stomach. The anti-incontinence segment was constructed from a tapered and reimplanted ileal segment. All patients underwent preoperative and postoperative measurements of serum pH, serum electrolytes, and urinalysis. Serum gastrin was measured in all patients postoperatively. Followup from surgery ranged from 47 to 61 months (mean 54.4). RESULTS: All 9 patients demonstrated electrolyte neutrality in serum on long-term followup. Postoperative serum pH (mean 7.40) was significantly different (p < 0.01) from preoperative serum pH (mean 7.36) and serum bicarbonate was also significantly different (p < 0.01) preoperatively versus postoperatively (mean 22.3 versus 25.14). Urine pH values were not significantly different throughout the study. One patient with mildly acidic urinary pH (6.0 to 6.5) had ulcerative skin changes at the stoma site. Three patients had elevated serum gastrin levels on short-term followup but all patients had normal serum gastrin levels on long-term followup. One patient, with persistent alkaline urine, had urolithiasis and symptomatic urinary tract infections. CONCLUSIONS: Our results demonstrate that a composite urinary reservoir constructed using gastric and intestinal segments achieved serum electrolyte neutrality on long-term followup. These results indicate a long-term metabolic advantage over other intestinal reservoirs associated with hyperchloremic metabolic acidosis and may be beneficial in patients compromised by either preexisting metabolic acidosis or the short bowel syndrome.

Adult↗
PubMed1997

Spot urine osmolality, age and bladder capacity as predictors of response to desmopressin in nocturnal enuresis.

The objective of the current study was to find a cost-effective way of correlating spot urine osmolalities, bladder capacity and age in patients with monosymptomatic nocturnal enuresis with response to treatment with desmopressin (Minirin, DDAVP). A total of 35 children fulfilled the entry criteria and were included in the study. Constipation was eliminated in these children by appropriate enema treatment and diet adjustment prior to enrollment. Urine samples were collected at home at times that would best reflect fluctuations in plasma vasopressin levels (08:00, 16:00 and 22:00) over three consecutive 24-hour periods. Maximal functional bladder capacity was determined from the largest voided volume. A 2-week dose-titration treatment period with intranasal desmopressin was then conducted. With doses of desmopressin being increased by 10 micrograms every 3 days. Response to desmopressin treatment was then assessed and factors that were observed to be markers of a favourable response were noted. Of the 35 children, 27 demonstrated a complete response to desmopressin treatment, at doses of 10-30 micrograms. Spot urine osmolalities were not predictive of the response to desmopressin (P > 0.1). In contrast, there was a significant correlation between a high maximum functional bladder capacity and response to desmopressin (P = 0.006). Age was also predictive of a good response to desmopressin treatment (P = 0.008).

Administration, Intranasal↗
PubMed1994

Age as a prognostic factor in the malignant melanoma population.

BACKGROUND: The incidence of malignant melanoma is increasing faster than any other cancer, and the state of Florida has one of the highest incidence of melanoma in the United States. This increased incidence is thought to be due to the intense sunlight exposure and ultraviolet radiation exposure in the elderly population. With the increased emphasis on issues of aging, it is appropriate to study the role of age as a prognostic factor for malignant melanoma in the Florida population. METHODS: A retrospective, computer-aided search identified 442 consecutively registered patients with malignant melanoma at the Cutaneous Oncology Program. All patients had stage 1 or 2 disease (cutaneous disease only) at diagnosis. Prognostic variables analyzed included the most powerful factors for stage 1 and 2 melanoma, tumor thickness, ulceration, and Clark level of invasion. Other prognostic variables included in the analysis were the clinical variables of sex and primary site (axial vs. extremity). The population was divided into patients < or = 65 and > 65 years of age. RESULTS: Significant disease-free survival differences were encountered in the older population, with only 55% of the elderly population being disease free at 5 years compared with 65% for the younger population (p = 0.0073). However, a greater percentage of patients with melanoma who were > 65 years of age had ulcerated lesions (17.5% vs. 12.9%) and a greater percentage of thick lesions at diagnosis (67.2% vs. 62.7%). Both of these prognostic factors would bias the older population with a poorer survival. A stepwise regression analysis of the entire population was performed, treating age as a continuous variable. Surprisingly, increasing age along with tumor thickness were the only significant predictors for disease-free survival. After inclusion of these two prognostic variables, none of the other prognostic factors, including Clark level, ulceration, sex, and primary site, added to the prognostic model. CONCLUSIONS: From this analysis, it is apparent that geriatric patients with melanoma have a worse prognosis than a younger control population, even after the correction for the more commonly cited prognostic factors. This information should be used in mathematical modeling to identify high-risk populations who are candidates for perhaps more aggressive primary or adjuvant therapies.

Adult↗