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Biomedical subjects

B M Churchill

Publications and source records attributed to B M Churchill.

At least 37 records · Page 2Linked to original sources
PubMed1996

Minimizing stomal stenosis in appendicovesicostomy using the modified umbilical stoma.

PURPOSE: We describe creation of a modified umbilical stoma as part of continent urinary diversion using appendicovesicostomy. MATERIALS AND METHODS: Umbilical stomas were created using the eversion-inversion principle in 25 patients undergoing appendicovesicostomy. RESULTS: Mean followup was 3 years. Cosmesis of the umbilical stoma was good in all cases. Stomal stenosis required surgical revision in 8% of cases. CONCLUSIONS: We recommend our modified umbilical stomal technique for appendicovesicostomy because it allows good cosmesis without compromising stomal function.

Appendix↗
PubMed1996

The dartos flap as an adjunct in preventing urethrocutaneous fistulas in repeat hypospadias surgery.

PURPOSE: Vascularized flaps for repeat hypospadias repair are often limited. We report our experience with the dartos flap in children undergoing secondary hypospadias and complex urethral repair. MATERIALS AND METHODS: The dartos flap is fibroadipose tissue between the scrotal skin and tunica vaginalis layers with its vascular pedicle based at the penoscrotal angle. The flap reaches the distal penile shaft without tension. Eight patients 1 to 17 years old (mean age 6) underwent urethral surgery and an interposed dartos flap procedure in 1994 to 1995. RESULTS: Of 6 patients cosmesis was excellent in 84%, erections were straight in 100%, and urinary streams were of good quality and without fistula in 100% after repeat hypospadias surgery. Following staged repair for anterior urethral valves a urethrocutaneous fistula developed in 1 patient and following urethral duplication repair results were excellent in 1. Mean followup was 1 year. CONCLUSIONS: The dartos flap is easy to mobilize and it provides excellent coverage for repeat proximal hypospadias surgery, since the dartos remains undisturbed. We endorse its use for complex urethral surgery and believe that the extra layer of closure helps to prevent urethrocutaneous fistulas.

Adolescent↗
PubMed1995

Voiding efficiency after ureteral reimplantation: a comparison of extravesical and intravesical techniques.

The purpose of our study was to examine postoperative changes and recovery in voiding efficiency after intravesical and extravesical ureteral reimplantation. Retrospective review was performed of 188 cases. Inclusion criteria were the presence of primary vesicoureteral reflux and the absence of previous lower urinary tract surgery. Voiding efficiency after ureteral reimplantation was assessed based on post-void residual volume measurements. It was found that postoperative voiding efficiency of patients in the extravesical unilateral group was similar to that in the intravesical group, while the extravesical bilateral group had a statistically significantly higher proportion of patients with transient voiding inefficiency. A statistically higher proportion of those in the extravesical bilateral group also required some form of urinary catheter drainage for a longer period. However, on more prolonged followup all evaluable patients in the 3 groups fully regained voiding efficiency.

Adolescent↗
PubMed1995

Bilateral congenital midureteral adynamic segments.

Two cases of congenital midureteral adynamic segments are presented. Both children were successfully managed with excision of the lesions and primary reanastomosis. Pathologic examination revealed probe-patent ureters with muscular disarray, suggesting functional obstruction. Appropriate management of the anomaly was dependent on precise radiographic localization of the area of narrowing, and for this retrograde urography was essential. Primary ureteroureterostomy was successful in both cases. In this report we discuss the diagnosis, embryology, radiographic evaluation, and management of this rate situation.

Humans↗
PubMed1995

Extravesical detrusorrhaphy for refluxing ureters associated with paraureteral diverticula.

OBJECTIVES: To demonstrate the effectiveness of an extravesical approach to refluxing ureters associated with paraureteral diverticula. METHODS: Over a 39-month period, 23 children underwent repair of Hutch diverticula with refluxing ureters using an extravesical approach. Seventeen had unilateral reflux with an ipsilateral diverticulum, 4 had bilateral reflux with a unilateral diverticulum, and 2 had bilateral reflux with bilateral diverticula. Overall, 25 ureters with associated diverticula were repaired. RESULTS: Twenty ureters were repaired with a nondismembered technique and 5 with a dismembered technique. Twenty-two of the 23 patients (96%) were successfully repaired with this approach. Three patients had transient reflux postoperatively, which resolved spontaneously within 6 months. One patient who underwent bilateral dismembered procedures for bilateral diverticula has persistent unilateral grade II reflux postoperatively. No patient developed ureteral obstruction. CONCLUSIONS: The major advantage of this technique is seen in the minimal postoperative morbidity. The extravesical approach is a safe, simple, and effective method for the management of a refluxing ureter with an associated diverticulum.

Adolescent↗
PubMed1995

Contradictory supranormal nuclear renographic differential renal function: fact or artifact?

We previously reported contradictory supranormal nuclear renographic differential renal function in cases of unilateral hydroureteronephrosis, in which the kidneys with hydroureteronephrosis paradoxically had a greater differential function than the contralateral normal mate, based on diethylenetriaminepentaacetic acid (DTPA) nuclear renography. To evaluate whether DTPA supranormal differential function represented true hyperfunction, patients with DTPA supranormal differential function were evaluated with dimercaptosuccinic acid (DMSA) nuclear renography and the results were compared. A total of 16 patients with unilateral hydronephrosis was identified to have DTPA differential function of 53% or more. They were younger than age 1 year and had never undergone any urological surgery. In all 16 patients the DMSA differential function (mean 51.1%, range 42 to 57%) was lower than their own corresponding DTPA differential function (mean 58.3%, range 53 to 66%, p < 0.0001). In addition, the DMSA differential function was not significantly different from the intuitively anticipated mean of 50% (p = 0.48). The DTPA supranormal differential function identified in our patients was not corroborated by the DMSA differential function. With recent evidence that DMSA differential function may be a better predictor of outcome following relief of unilateral ureteral obstruction consideration should be given to using DMSA as a potentially more relevant method for differential function measurement in the setting of unilateral hydronephrosis. Conversely, until the potential deficiencies of DTPA are fully understood caution should be exercised in the interpretation of DTPA differential function in the setting of hydronephrosis.

Artifacts↗
PubMed1995

Evaluation of pediatric hydronephrosis using individualized pressure flow criteria.

In pursuit of a diagnostic modality better able to assess collecting system urine transport characteristics while operating within physiological ranges, a new set of guidelines for the pressure flow study was proposed. An infusion rate individualized for each patient was chosen based on a calculated estimate of the maximum physiological urine output, adjusted for patient size and age. The upper limit of normal renal pelvic pressure used was 14 cm. water. We evaluated 37 renal units with grade 3 or 4 hydronephrosis with the individualized pressure flow study. Patient age ranged from 0.2 to 12 years (median 1.1). Calculated individualized infusion rates ranged from 1.3 to 12.5 ml. per minute and resulting renal pelvic pressures ranged from 7 to greater than 40 cm. water. In each patient the corresponding renal pelvic pressure resulting from a fixed 10 ml. per minute infusion rate was uniformly equal to or higher than the corresponding individualized study pressures (p < 0.0001). Disagreement between the individualized and fixed rate pressure flow studies was highest in the younger patients. The correlation coefficient between diuretic nuclear renography half-times and individualized pressure flow results was 0.09, indicative of a random association between the 2 variables. By using individualized infusion rates based on the calculated estimate of the maximum physiological urine output, much of the falsely high pressures induced by nonphysiologically high fixed infusion rates in pediatric patients can be avoided.

Child↗
PubMed1995

Concomitant bladder neck closure and Mitrofanoff diversion for the management of intractable urinary incontinence.

In a 7-year period 28 patients 1 to 20 years old have undergone bladder neck closure in conjunction with Mitrofanoff diversion for the management of severe incontinence. Surgery was performed as a salvage procedure in 19 patients and as a primary anti-incontinence procedure in 9. At a mean followup of 29 months 27 of 28 patients (96%) were totally continent, requiring no pads. Bladder neck closure was primarily successful in 24 of 28 patients (86%) and 25 (89%) had stable upper tracts. Five patients had bladder calculi and 5 required stomal revisions. One child had a bladder perforation associated with blunt trauma. Bladder neck closure and Mitrofanoff diversion were done without bladder augmentation in 11 cases and augmentation was performed previously or concurrently in the remainder. Four patients who did not initially undergo augmentation required later augmentation (2 for hydronephrosis and 2 for persistent incontinence). We conclude that bladder neck closure in conjunction with Mitrofanoff diversion is highly efficacious in achieving continence in a highly complex subgroup of patients with intractable urinary leakage. With careful patient selection and diligent followup total continence can be achieved in this most difficult patient population.

Adolescent↗
PubMed1995

The effect of temporary cutaneous diversion on ultimate bladder function.

We evaluated the effect of temporary cutaneous diversion on bladder function in cases of various congenital uropathies. The clinical courses of patients who underwent reversal of vesicostomy or pyelostomy/ureterostomy in a 7-year period were reviewed. Indications for diversion included azotemia, massive hydronephrosis, high grade reflux and/or incomplete bladder emptying. Mean age at diversion was 15 weeks. Overall 75 cases were evaluated (posterior urethral valves in 31, neurogenic bladder in 16, reflux in 14, the syndrome of vertebral defects, anal atresia, tracheoesophageal fistula with esophageal atresia, and radial and renal anomalies in 8 and other in 6). Of 55 patients who underwent undiversion by direct closure only 2 required later augmentation for bladder/renal deterioration. Excluding the myelomeningocele patients on clean intermittent catheterization 45 of 46 who underwent direct closure were able to void spontaneously with acceptable post-void residuals. Urodynamics in 22 cases revealed normal bladder capacity at pressures below 30 cm. water in 19 (86%) after direct closure. We conclude that after a period of defunctionalization approximately 75% of children will have essentially normal bladder function. The frequency of bladder augmentation varied from 54% in patients with myelomeningocele to 14% in those with vesicoureteral reflux. This observation suggests that the need for bladder augmentation in the remaining patients is more related to the effect of the primary pathological condition on the detrusor rather than the diversion itself.

Cystostomy↗
PubMed1995

Donor aortic cuff reduces the rate of anastomotic arterial stenosis in pediatric renal transplantation.

A total of 333 pediatric renal transplantations performed at our institution between January 1977 and July 1994 was retrospectively reviewed to provide guidelines for minimizing the incidence of transplant renal artery stenosis. The patients who had renal artery stenosis were 3 months to 17.5 years old (median age 9.3 years) at the time of transplantation and the condition was diagnosed 2.2 months to 2.5 years (median 4.2 months) after transplantation. Renal artery stenosis was diagnosed in 19 transplants (19 of 333, 5.7%) as a result of severe hypertension or renal function deterioration. Stenosis occurred at the anastomosis in 7 cases (37%) and distal to the anastomosis in 12 (63%). Transplantations performed with a donor aortic cuff resulted in a lower rate of renal artery stenosis at the anastomosis (0 of 193, 0%) compared to those performed without a cuff (7 of 140, 5.0%, p = 0.0021). The rate of renal artery stenosis distal to the anastomosis was not different regardless of whether a cuff was used (5 of 193 cases, 2.6%) or not (7 of 140, 5.0%, p = 0.37). End-to-end anastomoses to internal iliac arteries, which were always performed without cuffs, had a particularly high rate of renal artery stenosis (3 of 10, 30%) compared to end-to-side anastomoses performed without cuffs (4 of 130, 3.1%, p = 0.0080). Bench surgery or multiple renal arteries did not adversely influence the rate of renal artery stenosis. With prompt diagnosis and treatment the actuarial graft survival of the transplants with renal artery stenosis was similar to that of the transplants without renal artery stenosis (p > 0.05).

Actuarial Analysis↗
PubMed1995

Functional characteristics of the reconstructed neourethra after island flap urethroplasty.

To test the neourethra objectively in cases judged to be clinical successes after transverse island flap hypospadias repair, we analyzed uroflowmetry data (peak flow, voided volume and ultrasonically determined post-void residuals) after repair. Patients were included if they were old enough to void volitionally and flow data were available after fistula or stricture repair. Flow data were then plotted on previously published age-dependent nomograms from normal controls. Of 80 boys available for study 51 required no secondary procedures, 16 subsequently underwent fistula repair and 13 had strictures opened. After all primary and secondary procedures 55 patients (69%) had peak flows within the normal range and 25 (31%) had peak flows below the normal range. Of the 51 boys who never had fistulas and/or strictures 37 (73%) had normal flows while 18 of 29 (62%) who underwent fistula and/or stricture repairs had normal flows (p < 0.05). Residual volume was less than 10% of voided volume in 44 of the 51 boys who clinically had no problems postoperatively, in 8 of the 13 who had strictures opened and in 15 of the 16 who underwent fistula repairs. We conclude that the neourethra is functionally equivalent to a normal urethra in most boys after transverse flap urethroplasty. A majority of boys will have normal flow even after stricture or fistula repair.

Child, Preschool↗
PubMed1995

Histologic studies of intravesical oxybutynin in the rabbit.

Intravesically applied oxybutynin has been reported to have no significant systemic anticholinergic side effects, with excellent efficacy in the treatment of neurogenic bladder dysfunction. Currently, the morphologic effects of intravesical oxybutynin on the local bladder tissue are not well established. It is the purpose of this study to address this issue in an animal model. Thirty-nine New Zealand White female rabbits were catheterized daily and intravesical solutions instilled for as long as 30 days. In part A of the study, the overall histologic effects of intravesical oxybutynin were examined by comparing oxybutynin with saline administration. Part B of this study compared the relative effects of crushed oxybutynin tablets and pure oxybutynin powder. The bladder histology and urine microbiological studies were analyzed in a blinded fashion. We found that the crushed oxybutynin tablets and saline administered intravesically produced similarly mild inflammation in the bladders (p < 0.05). When we compared the crushed oxybutynin tablets and pure oxybutynin powder, however, the crushed tablet group was found to have a mild eosinophilic infiltrate seen in 5 of 9 animals, which was not observed in any of the animals in the other groups (p = 0.029). Qualitative and quantitative analyses of the microbiological findings were not different among the different groups (p > 0.05). Our findings support the clinical use of intravesical oxybutynin as being safe for local tissue. However, consideration should be given to the use of the pure powdered form of oxybutynin, since the crushed oxybutynin tablets may lead to allergic reactions.

Administration, Intravesical↗
PubMed1994

The sensitivity of pressure specific bladder volume versus total bladder capacity as a measure of bladder storage dysfunction.

Assessment of bladder storage function requires an accurate measure of bladder capacity and pressure. Pressure specific bladder volume is the volume that a bladder can accommodate at a specific pressure. A total of 21 consecutive children with neurogenic bladders who were candidates for bladder augmentation based on standard clinical criteria (upper urinary tract deterioration, incontinence and infection) was studied to determine the efficacy of pressure specific bladder volume as a measure of bladder dysfunction. Urodynamic indexes were compared to previously established nomograms. All 21 patients had bladder volumes at pressures of 30 cm. water or less, which decreased below the 5th percentile as determined by the nomogram. In 7 patients (33%) normal total bladder capacity was achieved at the expense of elevated storage pressures. Pressure specific bladder volume provides a better measure of bladder storage function than total bladder capacity because it relates volume to intravesical pressure, does not rely on a subjective end point to bladder filling, and is objective and reproducible.

Adolescent↗
PubMed1994

Contradictory supranormal differential renal function during nuclear renographic investigation of hydroureteronephrosis.

We selected a group of children with unilateral hydroureteronephrosis to assess the significance of the differential renal function as determined by nuclear renography as a factor in defining obstructive dilatation. All children who presented to our institution during a 21-month period with unilateral hydroureteronephrosis and a normal contralateral kidney were reviewed. Patients with reflux or bladder pathology were excluded, resulting in 13 evaluable patients younger than age 2 years. Diuretic renography was performed using 99mtechnetium-diethylenetriaminepentaacetic acid in accordance with the well tempered renogram. Ancillary studies included voiding cystourethrography, ultrasonography and/or excretory urography. Of the 13 patients 5 had a differential function greater than 55% in the hydronephrotic kidney. Ten of the 13 patients, including the 5 with supranormal function, underwent surgical correction in the form of ureteral reimplantation for recurrent infections, increasing hydronephrosis, decreasing or decreased function and loss of parenchyma. Stenotic distal adynamic ureteral segments with proximal dilatation were confirmed in all cases. The implication by nuclear renography that a dilated kidney has better function than its morphologically normal counterpart is at variance with any available clinical or experimental data. The etiology of this apparently elevated function is unclear and its presence on a renographic study should not be interpreted as suggestive that the kidney is free of risk of nephron loss. Management decisions should not be based solely on the differential function as determined by nuclear renography.

Child, Preschool↗
PubMed1994

Intrarenal resistive index correlates with renal pelvis pressure.

Elevation in the intrarenal resistive index has been suggested by many to be a physiological parameter useful for detecting functionally significant hydronephrosis. It is currently unknown whether the intrarenal resistive index changes truly reflect the changes in collecting system pressure or whether they are simply a coincidental epiphenomenon. The purpose of this study is to establish the relationship between intrarenal resistive index and collecting system pressure. Between August 1992 and October 1993, 9 patients younger than 1 year underwent a percutaneous pressure-flow study as part of hydronephrosis evaluation. During the pressure-flow study intrarenal resistive index was measured serially with simultaneous renal pelvis pressure readings. In all patients the index increased as the renal pelvis pressure increased. Furthermore, using the experimentally derived proximal tubular pressure of 14 cm. water as the probable threshold for functionally normal collecting system pressure, it was found that all intrarenal indexes of 82% or less corresponded to renal pelvis pressures of less than 14 cm. water, while all of those greater than 82% corresponded to renal pelvis pressures greater than 14 cm. water. By combining several lines of evidence, it appears probable that as maximal diuresis induced by physiological and pharmacological means leads to acute transient elevation in renal pelvis pressure in a functionally obstructed collecting system, the intrarenal resistive index is capable of reflecting this dynamic elevation in renal pelvis pressure and potentially able to distinguish physiologically significant upper urinary tract obstruction from nonobstructive dilatation.

Blood Flow Velocity↗
PubMed1994

Loss of elasticity in dysfunctional bladders: urodynamic and histochemical correlation.

To store adequate volumes of urine at low safe pressures an elastic bladder wall is required. We developed 2 new techniques to measure this ability in our urodynamic laboratory: pressure specific bladder volume, which measures the bladder capacity at a given pressure, and dynamic analysis of bladder compliance. Recently, morphometric and histochemical techniques have been used to determine the relative volume of connective tissue in the bladder wall and to measure the 2 major types (I and III) of collagen within the bladder wall. These methods quantitate 3 parameters of bladder ultrastructure: 1) relative volume of per cent connective tissue, 2) ratio of connective tissue to smooth muscle and 3) ratio of type III to type I collagen. These parameters have been shown to be abnormally elevated in patients with dysfunctional bladders compared to normals. The purpose of the study was to describe the ultrastructural changes that occur in the wall of dysfunctional bladders and to determine the ability of these new urodynamic techniques to detect reliably the clinical effect of these histological changes. The study included 29 consecutive patients with dysfunctional bladders necessitating bladder augmentation. All patients had upper tract changes and/or were incontinent despite treatment with clean intermittent catheterization and pharmacotherapy. Preoperative urodynamic evaluation included measurement of the total bladder capacity, pressure specific bladder volume and dynamic analysis of bladder compliance. Full thickness bladder biopsies were obtained from the dome of the bladders during augmentation. The per cent connective tissue and the ratio of connective tissue to smooth muscle were determined for all patients, and 4 unselected patients from this group had the ratio of type III to type I collagen determined. These histological results were compared to previously established normal values. All 29 patients had a decreased pressure specific bladder volume and dynamic analysis of bladder compliance, whereas 9 had a normal total bladder capacity. The per cent connective tissue was 35.19 +/- 2.84 and ratio of connective tissue to smooth muscle was 0.60 +/- 0.08 compared to normal values of 10.6 +/- 0.020 and 0.131 +/- 0.021, respectively (p < 0.05). Ratio of type III to type I collagen was also significantly elevated in the 4 samples analyzed (30.53 +/- 1.37 versus 24.00 +/- 2.50, p < 0.05). We conclude that poor storage function of poorly compliant bladders is secondary to an alteration in the connective tissue content of the bladder wall. Furthermore, these pathological ultrastructural changes are universally reflected by an abnormally low pressure specific bladder volume and dynamic analysis of bladder compliance. This strong association validates the use of these parameters and suggests that they are urodynamic indicators of a loss of elasticity in bladder wall.

Adolescent↗
PubMed1994

Bladder augmentation: ureterocystoplasty versus ileocystoplasty.

The primary advantages of augmentation ureterocystoplasty include the absence of mucus, lack of electrolyte absorption from the augmenting segment and the avoidance of gastrointestinal complications. We tested whether the ureteral patch offers sufficient biomaterial to increase adequately the storage efficiency of dysfunctional bladders. Between April 1989 and November 1992, 8 children with unilaterally dilated and tortuous ureters underwent bladder augmentation using detubularized reconfigured megaureter. Clinical and urodynamic outcomes were compared between these patients and a control group of 8 children matched in age and diagnosis who had undergone ileocystoplasty during the same time. Total bladder capacity, pressure specific bladder volume at pressure less than 30 cm. water, dynamic analysis of bladder compliance, continence and upper tract status were compared between the 2 groups before and after augmentation. Preoperatively, all 16 patients were incontinent with high pressure, small capacity bladders, and all had upper tract changes. Postoperatively, the mean total bladder capacity was 417 ml. in the ureterocystoplasty group and 381 ml. in the ileocystoplasty group (p > 0.05), while the mean pressure specific bladder volume was 413 and 380 ml. (p > 0.05), respectively. Pressure specific bladder volume and dynamic bladder compliance were normal in 7 of 8 patients (87.5%) in the ureterocystoplasty group. All patients in the ileocystoplasty group had normal postoperative urodynamics. We conclude that megaureters subtending effete kidneys may be used to improve the storage function of dysfunctional bladders to the same extent as that achieved with ileum without the complications pursuant to ileocystoplasty, and that the improvement is maintained long term.

Adolescent↗