PubMed Health⌕ Search

Biomedical subjects

B M Churchill

Publications and source records attributed to B M Churchill.

At least 19 recordsLinked to original sources
PubMed2003

Estimation of glomerular filtration rate and bladder capacity: the effect of maturation, ageing, gender and size.

OBJECTIVE: To show that glomerular filtration rate (GFR) and bladder capacity (BC) develop isometrically, and to provide graphs for estimating GFR and BC for specific individuals of any age, sex, height and weight, for cystometric purposes. MATERIALS AND METHODS: GFR and BC data were collected from published reports; graphs relating GFR and BC to age, sex, height and weight were obtained by using a computerized curve-fitting technique that minimizes the 1.1 power of the absolute error. RESULTS: The plots show the GFR and BC for individuals of 10th, 50th and 90th percentile height and weight as a function of age and sex for different physiological conditions. GFR increases up to age 20 years and thereafter declines, whereas GFR per unit body surface area reaches a maximum at 3.25 years old and declines thereafter. CONCLUSIONS: The clinical management strategy to preserve or enhance renal function in paediatric and adult nephrological disease should incorporate the present data on development, growth, ageing and deterioration of function. These data should be used when interpreting cystometrograms and evaluating compliance. The graphs are useful for clinically estimating GFR and BC, especially when estimating infusion rate and BC for individual patients. BC and GFR develop isometrically with a proportionality constant of 4.56 min, except from birth to 1.5 years of age. Accordingly, individuals with healthy urinary systems, irrespective of age, sex and size, in the same physiological conditions have, on average, the same time to reach BC, ranging from 7 h at a normal 1% GFR to 41 min at the maximum diuresis of 10% GFR.

Adolescent↗
PubMed2001

Pediatric urine testing.

Today, urinalysis is one of the most common clinical tests ordered for adult and pediatric patients. Because urine specimens are usually readily available and are obtained noninvasively, the urine testing is well suited for children. This article discusses the most common urine tests performed in children for screening purposes and also less common tests for diagnosis of specific disorders. Special considerations regarding urine specimen collection in children are discussed. Some simple tests that are underused by clinicians are mentioned, as are some exciting new molecular applications of urine testing.

Child↗
PubMed2001

Enuresis.

The authors do not have all of the data about enuresis, and many children are subject to relapses or failure of treatment. There is no cause for despondency, however. Enuresis is no longer a mystery. Good data exist about the natural history, epidemiology, and etiology of enuresis. In addition, multiple treatment modalities are available to practitioners. This article has sought to review the scientific literature and to relate the authors' experience with enuresis. The authors recommend a treatment program for children with monosymptomatic nocturnal enuresis that includes removal of caffeine from the diet. Enuretic children do not consume enough fluid, and the authors recommend that the daily fluid requirement be divided during the day: 40% in the morning, 40% in the afternoon, and 20% in the evening, with no restriction of fluid. Normalization of small functional bladder capacities may help to cure enuresis and has an effect on the efficacy of other therapies. Treatment of enuretics with antibiotics is effective in children with UTI, bacteriuria, or cystitis cystica. DDAVP has been shown to be effective in the treatment of enuresis, especially in children who have achieved a normal functional bladder capacity. Bladder alarm systems also offer a potential cure of enuresis, are inexpensive, and show a low relapse rate.

Behavior Therapy↗
PubMed2001

Dysfunctional elimination syndrome in children without obvious spinal cord diseases.

Elimination dysfunction is a functional disease that encompasses the urinary and GI tracts. Because the presentation is varied and ED is a disease of exclusion, a thorough history and physical examination are mandatory. Noninvasive management that includes the "fundamental four" and continuous engagement and encouragement of the patient and family are the pillars of treatment. For patients who are refractory to this approach, new research in children-directed biofeedback research shows promise.

Biofeedback, Psychology↗
PubMed2001

Dysfunction of the lower urinary and distal gastrointestinal tracts in pediatric patients with known spinal cord problems.

Destruction of the urinary tract in children with elimination, storage, and holding dysfunction of the lower urinary and the distal GI tracts is caused primarily by high intravesical pressure. UTI accelerates this process. The LPP and the status of the urethral control mechanism and its relationship to the detrusor are the primary determinants of intravesical pressure. Intravesical pressures of more than 40 cm H2O are dangerous because they cause a pressure gradient that is transmitted proximally to the renal papillae, which results in the cessation of renal blood flow and a loss of renal function over time. Hydroureteronephrosis, VUR, UTI, urinary incontinence, and calculi formation also may occur. If these dangerously high intravesical pressures remain untreated, renal failure is likely to occur over time. These children then require dialysis or renal transplantation to survive, which is tragic and represents an enormous economic cost to society. Renal failure and upper urinary tract damage is nearly 100% preventable with early and appropriate evaluation and treatment. CIC is a crucial part of the management of these children and has been shown to be safe and effective, even in newborn boys. The use of the Credé maneuver (i.e., manual compression) to empty the bladder is obsolete and should be abandoned. The distal GI tract is inseparable from the lower urinary tract and must be treated simultaneously. Failure to treat the distal GI tract yields poor clinical results and much patient dissatisfaction and makes it difficult or impossible to treat the child's urinary tract problem successfully. Bowel-management programs must include daily high water and fiber intake, together with digital perianal stimulation or fecal extraction. Neuropathic bladder and bowel problems that are intractable to conservative medical and mechanical (i.e., CIC and digital perianal stimulation or fecal extraction, respectively) management almost always can be corrected surgically with high success rates in cooperative patients. Finally, neuropathic bladder and bowel problems can be extremely isolating and debilitating problems. Psychologic counseling and emotional support must be provided as needed. The care that these patients receive must be organized, comprehensive, and correlated with these patients' lifestyles. If these children are evaluated and treated early, they have the potential to live long, healthy, and productive lives.

Biophysical Phenomena↗
PubMed2001

Prototype system for enhancing cystometric analysis with special emphasis on the pediatric population.

BACKGROUND AND PURPOSE: A urodynamic test system of improved accuracy and reliability was developed and implemented for enhancing cystometry. This system integrates known medical information, including the specialized problems of pediatric urodynamics, with the cystometric and imaging data. METHODS: After the requirements for the ideal cystometrogram test unit were established, a system was constructed, calibrated, and implemented in clinical practice. The patient's age, size, and sex are used to produce a patient-specific pressure-volume template for the cystometrogram test. RESULTS: This template showed the minimal and normal bladder capacities and the physiologically safe, equivocal, and dangerous pressure fields coded with symbolic colors. Different time averages of the pressure data were used to show bladder factors such as compliance and instability. The templates with data were presented automatically (therefore objectively) without operator intervention on monitors during testing and as printed copies on completion. CONCLUSIONS: The presentation of data in an easily understood format facilitates effective communication between the urologist, referring physician, and patient. Some of the physiological and statistical problems in pediatric urodynamic testing are efficiently and accurately resolved by this system, resulting in better analysis and diagnostic capabilities.

Automation↗
PubMed1999

Urinary continence after staged bladder reconstruction for cloacal exstrophy: the effect of coexisting neurological abnormalities on urinary continence.

PURPOSE: We determined whether there is a difference in the incidence of urinary continence in cloacal and classic bladder exstrophy after staged bladder neck reconstruction using the Young-Dees-Leadbetter technique. MATERIALS AND METHODS: We reviewed the records of patients with cloacal and classic bladder exstrophy who underwent staged bladder neck reconstruction from 1971 to 1997. RESULTS: The Young-Dees-Leadbetter bladder neck reconstruction was completed in 23 patients with cloacal exstrophy, of whom 5 (22%) became continent and 18 (78%) have persistent incontinence. A clinically apparent neurological abnormality significantly hindered the achievement of continence. Specifically 1 of the 13 children (7%) with versus 4 of the 10 (40%) without a neurological abnormality became continent (p <0.05). In contrast, staged reconstruction of classic bladder exstrophy resulted in urinary continence in 67 of the 82 patients (82%). Of the 67 continent patients 23 (34%) cannot void and require intermittent catheterization. None of the patients with classic exstrophy had a neurological deficit. CONCLUSIONS: The ability of the Young-Dees-Leadbetter bladder neck reconstruction to result in urinary continence significantly differs in the cloacal and classic bladder exstrophy populations (22 versus 82%, p <0.001). Our findings also suggest that a coexisting neurological abnormality significantly hinders the ability to reconstruct a functional bladder in patients with cloacal exstrophy.

Bladder Exstrophy↗
PubMed1998

Ureteral opening pressure: a novel parameter for the evaluation of pediatric hydronephrosis.

PURPOSE: The antegrade nephrostogram is an important tool in the evaluation of the upper urinary tract. However, the information currently provided by a nephrostogram is largely limited to anatomical details. To establish a meaningful pressure-flow parameter that may be incorporated into a routine nephrostogram, we evaluated the ureteral opening pressure (defined as the pressure at which contrast material is first seen beyond the suspected site of obstruction) and correlated these findings with the results of pressure-flow studies performed with an external infusion and/or furosemide induced diuresis. MATERIALS AND METHODS: A total of 52 renal units were studied under a prospective pressure-flow study protocol. All patients had grade 3 or 4 hydronephrosis (Society of Fetal Urology classification) and patient age range was 0.2 to 12 years (median 1.1). The suspected sites of obstruction were the ureteropelvic and ureterovesical junctions in 42 and 10 renal units, respectively. With the patient under general anesthesia 22 gauge percutaneous nephrostomy needles were inserted. Pressure-flow studies with an external infusion and/or furosemide induced diuresis were then performed. As the renal pelvic pressure progressively increased during the course of the pressure-flow studies, the renal pelvic pressure at which contrast material was first seen to appear distal to the suspected site of obstruction was recorded as the ureteral opening pressure. Ureteral opening pressures were compared to the results of the pressure-flow studies. RESULTS: With a positive test defined as renal pelvic pressure greater than 14 cm. water, positive ureteral opening pressures were associated with positive pressure-flow study results in 100% of the cases, regardless of which form of pressure-flow study was used or where the suspected site of obstruction was located. In contrast, negative ureteral opening pressures had specificities and negative predictive values of only 19 to 57%, depending on the form of the pressure-flow study and the suspected site of obstruction. CONCLUSIONS: An elevated ureteral opening pressure was 100% predictive of obstruction and may obviate the need for more elaborate pressure-flow analyses. However, if the ureteral pelvic pressure remained low, the possibility of a potentially significant obstruction could not be definitively eliminated and further evaluation was required.

Child↗
PubMed1998

Urethral replacement with vascularized tunica vaginalis: defining the optimal form of use.

PURPOSE: Residual urethral defects after failed hypospadias surgery present difficulties in reconstruction. In these situations, repair using vascularized tissue flaps remains ideal, yet challenging. In order to offer more surgical alternatives in these cases, the use of vascularized tunica vaginalis flaps as urethral replacements has recently been established in an animal model. We undertook the following studies to further define the role of tunica vaginalis in urethral reconstruction. MATERIALS AND METHODS: A vascularized flap of tunica vaginalis was used to replace an experimentally created 25-30 mm. gap in the anterior urethra of 26 rabbits, either as an onlay or tube flap. A control group consisting of 7 animals underwent only a segmental anterior urethral resection and primary re-anastomosis. RESULTS: Satisfactory urethral healing occurred in all control animals that survived the procedure. All 8 animals which had tunica vaginalis tube flap reconstruction underwent contracture of the neourethra probably secondary to the presence of striated cremasteric muscle elements brought with the tunica during mobilization. All 16 animals available for long term study in the onlay flap group had excellent flap viability and 100% urethral patency rates. The mesothelial lining of the tunica was seen to be replaced by a stratified epithelial lining similar to the urothelial lining of the native urethra. CONCLUSION: The tunica vaginalis is a viable alternative to other tissues presently used for urethral replacement and can be used successfully as a vascularized onlay flap.

Animals↗
PubMed1997

Bilateral single ureteral ectopia: difficulty attaining continence using standard bladder neck repair.

PURPOSE: We reviewed the surgical results of the management of bilateral single ureteral ectopia, a rare congenital cause of severe urinary incontinence. MATERIALS AND METHODS: We reviewed the records of 6 girls and 1 male infant who presented to 1 institution with this diagnosis in a 10-year period. RESULTS: All patients were incontinent and 3 had undergone ureteral reimplantation as an initial procedure with persistent postoperative wetting. Of the 5 patients who underwent a total of 8 attempts at increasing bladder outlet resistance, including 3 Young-Dees-Leadbetter, 2 Kropp, 1 Stamey, 1 Burch and 1 pubovaginal sling procedure, 2 also underwent simultaneous bladder augmentation to increase bladder capacity. However, none of these children had satisfactory continence after the continence procedure. Three of these patients who subsequently underwent appendicovesicostomy with bladder neck closure are continent. The 2 remaining patients underwent initial appendicovesicostomy with bladder neck closure and augmentation, and they are also continent. CONCLUSIONS: In our series total day and nighttime continence was only achieved by bladder neck closure, appendicovesicostomy and augmentation. Attempts at increasing bladder outlet resistance in patients with bilateral single ectopic ureters led to suboptimal rates of success even when adequate bladder capacity had been ensured by simultaneous augmentation.

Adolescent↗
PubMed1997

Renal transplantation in children following augmentation ureterocystoplasty.

OBJECTIVES: To assess the impact of augmentation ureterocystoplasty on the success of cadaveric renal transplantation in children with dysfunctional bladders. METHODS: Two patients with end-stage renal failure secondary to dysfunctional bladders (one myelodysplasia and one posterior urethral valves) underwent augmentation ureterocystoplasty prior to renal transplantation in order to increase bladder capacity and improve compliance. RESULTS: Significant improvement of bladder storage function was achieved in both patients. By the use of megaureter for augmentation, untoward sequelae of enteric or gastric augmentation were obviated. Renal transplantation was successful in both patients. Both have normal renal function 4 and 3 years after transplantation. CONCLUSIONS: Renal transplantation into bladders previously augmented with megaureters is successful. The use of urothelial-lined biomaterial for augmentation avoids the potential complications of gastro- or enterocystoplasty, which are especially dangerous in transplant patients.

Child↗
PubMed1997

Intestinal metaplasia is not a strong risk factor for bladder cancer: study of 53 cases with long-term follow-up.

OBJECTIVES: Intestinal metaplasia often coexists with adenocarcinoma of the urinary bladder, suggesting to some investigators that it is premalignant. However, the natural history and long-term outcome of intestinal metaplasia in isolation are unknown. We report 53 cases of intestinal metaplasia of the urinary bladder followed for more than 10 years. METHODS: We reviewed the Mayo Clinic surgical pathology files between 1926 and 1996 and all patients with exstrophic bladder recorded in the files of the Hospital for Sick Children (Toronto, Ontario, Canada) and Dallas Children's Hospital (Dallas, Texas) between 1953 and 1987, and identified all patients with intestinal metaplasia of the bladder. RESULTS: A total of 53 cases were identified from both series, and none of the patients developed adenocarcinoma of the bladder. The Mayo Clinic series consisted of 24 patients. Nineteen of the 24 (79.1%) were alive without evidence of cancer (median follow-up 14 years, range 0.9 to 53), and 5 patients died of intercurrent disease (at 0.9, 4, 8, 11, and 53 years after diagnosis) without evidence of bladder cancer. The Dallas Children's Hospital and the Hospital for Sick Children series consisted of 29 patients. Twenty-seven of the 29 (93.1%) were alive without evidence of cancer (median follow-up 13 years, range 3 to 23.9). Two patients died of trauma (at 10.9 and 12 years after diagnosis) and at autopsy had no evidence of bladder cancer. CONCLUSIONS: Intestinal metaplasia of the urinary bladder is not a strong risk factor for adenocarcinoma or urothelial cancer.

Adenocarcinoma↗
PubMed1997

Outcome analysis of vesicoureteral reflux in children with myelodysplasia.

PURPOSE: Vesicoureteral reflux in children with myelodysplasia is usually secondary to abnormal bladder storage. The purpose of this study was to assess the outcome of vesicoureteral reflux in children with myelodysplasia. MATERIALS AND METHODS: We retrospectively analyzed the records of 319 children with myelodysplasia who presented to our institution between 1978 and 1985. Of these children 95 presented with or had reflux during followup and they were treated with prophylactic antibiotics. Clean intermittent catheterization and anticholinergic medication were added to the regimen when indicated. RESULTS: Reflux resolved in 63% of these patients with nonsurgical management. Temporary cutaneous vesicostomy was performed in 23 children (24%) with persistent high grade reflux or evidence of upper tract deterioration. Ureteral reimplantation and augmentation cystoplasty were performed in 18 (20%) and 8 (8%) patients, respectively. No patient had progression to chronic renal failure and scars developed in only 14 kidneys (10%). CONCLUSIONS: In the majority of cases (63%) reflux resolved with nonsurgical management. Reflux in these patients should not be treated in isolation. The management of reflux is primarily aimed at improving bladder storage. The combination of aggressive nonsurgical therapy and close observation is recommended. This regimen leads to the satisfactory resolution of reflux with minimal renal morbidity.

Child↗
PubMed1996

Pediatric renal transplantation into the abnormal urinary tract.

Many children with end-stage renal disease have significant urinary tract problems other than irreversible loss of native kidney function. These significant other urinary tract problems, if not corrected prior to transplantation, may significantly increase recipient mortality, graft loss, and patient morbidity. These other urinary tract problems may cause hydroureteronephrosis in the transplanted kidney, lead to an increased incidence of graft rejection, be the source of sepsis after subsequent immunosuppression, and cause hypertension. In addition, pre-existing urinary diversion, large interabdominal masses, or previous cancer require specific pre-transplant management plans. Potential pediatric transplant recipients with other significant urinary tract problems can be classified according to three parameters; anatomical extent, pathology, and pathophysiology of the significant other problems. Particular attention must be paid to pre-existing lower tract problems. Strategy must be worked out pre transplant as to how the lower urinary tract is going to store, hold, and empty urine. The means for assessing the potential recipients and strategies and techniques for correcting pre-existing problems have been summarized in this article.

Child↗
PubMed1996

Pressure decay half-life: a method for characterizing upper urinary tract urine transport.

PURPOSE: We examined the pressure dynamics of hydronephrotic kidneys after elevated renal pelvic pressure developed. MATERIALS AND METHODS: A total of 40 patients (44 renal units) 0.2 to 12 years old was evaluated. Transiently elevated renal pelvic pressure was induced with a percutaneous nephrostomy infusion. After renal pelvic pressure increased the infusion was stopped and the subsequent decrease in pressure with time was plotted as a pressure decay curve. The rapidity of the decrease in renal pelvic pressure was then quantitated as a half-life for each pressure decay curve. Pressure decay half-lives were compared to corresponding pressure flow study results and diuretic nuclear renography half-lives. RESULTS: Renal units without elevated renal pelvic pressure during infusion at a high physiological flow rate were associated with relatively rapid pressure decay, whereas those with elevated renal pelvic pressure during infusion were associated with much slower pressure decay (p < 0.0001). Diuretic nuclear renography half-lives had no correlation with collecting system pressure dynamics. CONCLUSIONS: Pressure decay half-life provides an objective quantitative measure of the relative tendency for elevated renal pelvic pressure to persist. When used in conjunction with other diagnostic modalities, it may be a useful parameter for a comprehensive assessment of the risk of pressure induced injury in hydronephrotic kidneys.

Child↗
PubMed1996

Percutaneous vacuum vesicolithotomy under direct vision: a new technique.

PURPOSE: The number of vesical calculi is increasing as the number of patients with intestinocystoplasty increases. We describe our technique for easily removing vesical calculi in children via an atraumatic percutaneous endoscopic approach. MATERIALS AND METHODS: The procedure involves percutaneous suprapubic puncture and direct visualization of the calculi via cystoscopy through the urethra or via a second suprapubic puncture when the bladder neck is closed. The stones are vacuumed up 1 at a time with suction tubing through the suprapubic working sheath in a controlled manner with no urethral trauma. Ten patients 3 to 16 years old (mean age 8) with vesicolithiasis underwent percutaneous vacuum vesicolithotomy under direct vision in 1993 to 1995. RESULTS: Two to 12 bladder calculi were extracted (mean 7). All calculi less than 1 cm. were removed by this procedure. All bladder calculi between 1 and 1.5 cm. were also removed but they required simultaneous electrohydraulic lithotripsy. There were no complications at a mean 1-year followup. Mean hospitalization was less than 24 hours (range 0 to 3 days). CONCLUSIONS: Percutaneous vacuum vesicolithotomy is highly successful, easy to perform and safe for extracting vesical calculi. Since the procedure is done through a percutaneous sheath, it is particularly suited to the individual with an absent, small caliber, sensitive or surgically reconstructed urethra.

Adolescent↗
PubMed1996

Outcome analysis of Mitrofanoff principle applications using appendix and ureter to umbilical and lower quadrant stomal sites.

PURPOSE: We compared the indications for and results of application of the Mitrofanoff principle using appendix and ureter to umbilical and lower quadrant stomal sites. MATERIAL AND METHODS: We created continent catheterizable conduits in 60 patients 3 days to 20 years old (mean age 8.8 years). The primary indication was refractory urinary incontinence associated with bladder or cloacal exstrophy, or anomalies in 31 cases. We constructed 38 umbilical (all appendix) and 22 lower quadrant (10 appendix and 12 ureter) stomas. Mean followup was 3 years. RESULTS: We preferred the umbilicus as a stomal site for its cosmetic value. The most common indication for a lower quadrant stomal site was preservation of the retroperitoneal course of the ureter. The stomal stenosis rate was 13 and 4% in patients with umbilical and lower quadrant stomas, respectively. We preferred the appendix as a conduit due to availability. Indications for the ureter as a catheterizable conduit were absence of an adequate appendix or presence of a healthy ureter after nephrectomy. The appendiceal and ureteral conduits were catheterizable in 94 and 84% of patients, respectively, and continence was achieved in 97%. CONCLUSIONS: In a complex group of patients with incontinence application of the Mitrofanoff principle yielded good results for either combination of stomal site or catheterizable conduit. Appendicovesicostomy to the umbilicus remains our preferred procedure.

Adolescent↗