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D T Wilcox

Publications and source records attributed to D T Wilcox.

At least 19 recordsLinked to original sources
PubMed2003

Accuracy of antenatal fetal ultrasound in the diagnosis of duplex kidneys.

OBJECTIVES: To assess the accuracy of ultrasound diagnosis of duplex kidneys in the fetus and to identify prognostic features of antenatal sonography associated with this diagnosis. METHODS: Retrospective identification of cases with an antenatal diagnosis of duplex kidney was made from computerized databases. Results of postnatal radiological investigations were obtained from the unit where delivery took place. RESULTS: A total of 75% of cases seen in a multidisciplinary fetal renal clinic were correctly diagnosed as having a duplex kidney. Prognostic sonographic features are described. Detection of two separate poles or a ureterocele were strongly associated with a correct diagnosis. Accuracy was increased when two or more prognostic features were seen. CONCLUSION: Accurate sonographic diagnosis of duplex kidneys in the fetus is possible in a dedicated multidisciplinary setting. Antenatal counseling and planning of postnatal care for the infant can be made with a high degree of certainty.

Female↗
PubMed2003

The validity of sacral ratios to identify sacral abnormalities.

OBJECTIVE: To test the repeatability and validity of a previously described sacral ratio measurement as a method for detecting sacral abnormalities, as the association between sacral abnormalities and neuropathic bladder is well known but the diagnosis of subtle sacral anomalies is often delayed. MATERIALS AND METHODS: Fifty sacral radiographs (from 30 patients with anorectal anomalies and 20 normal children) were viewed and reported as normal or abnormal by an expert spinal radiologist (reference standard). Sacral ratios (anteroposterior, AP, and lateral) were measured while unaware of origin by four investigators and the inter- and intra-observer variability examined. Validity was assessed by comparing individual sacral ratio values with the radiological diagnosis, using Pena's criteria for a normal sacrum (normal >/= 0.74 AP; >/= 0.77 lateral). RESULTS: Sacral ratio estimates were possible in 48 of the 50 selected radiographs. There was good repeatability of measurements and moderate variability among investigators (P > 0.1). For the 20 normal children the mean (sd) AP sacral ratio was 0.74 (0.156); in the 14 with anorectal conditions and a normal sacrum it was 0.87 (0.16) and in the 12 with an abnormal sacrum 0.64 (0.27). There was a difference (P < 0.02) among the three groups (analysis of variance) but there was wide variability in individual sacral ratios within each group, and considerable overlap of values between normal and abnormal sacra. When all sacra were defined as normal or abnormal using Pena's criteria, there was poor agreement using Cohen's kappa (AP and lateral view) with the radiological diagnosis by all four investigators. CONCLUSION: The sacral ratio has good inter- and intra-observer repeatability. The mean value for a normal AP ratio concurred with that described previously by Pena but the variability of values among similar patients was large, suggesting this single value is of limited value in discriminating a normal from an abnormal sacrum.

Analysis of Variance↗
PubMed2003

Extracellular matrix protein expression during mouse detrusor development.

BACKGROUND/PURPOSE: Extracellular matrix proteins are implicated in regulating cell proliferation and differentiation. The authors systematically analysed the expression of elastin; collagen types I, III, IV; laminin; and fibronectin during mouse detrusor muscle development, a period during which downregulation of detrusor proliferation and increasing smooth muscle differentiation is known to occur. METHODS: Embryonic days 14 (E14) and 18 (E18), and postnatal day 1 (D1) and week 6 (6wk) were examined, a period spanning the inception of the bladder to postnatal maturity. Immunohistochemistry of whole bladders was used to immunolocalise protein expression, and Western blot of dissected detrusor layers was used to semiquantify soluble protein expression. RESULTS: All proteins were detected at all 4 stages. Statistically significant increases were documented for elastin (E14 to 6wk), collagen type I (E18 to 6wk), collagen type III (D1 to 6wk) and laminin (E14 to 6wk). Fibronectin levels were relatively high up to D1, after which levels declined significantly. Collagen type IV levels decreased significantly (E18 to 6wk). CONCLUSIONS: The authors postulate that changing levels of laminin and fibronectin have opposing effects on the transition from proliferating primitive mesenchymal cells to differentiated detrusor muscle. Furthermore, changes in collagen type III and elastin may be important for bladder compliance.

Animals↗
PubMed2003

Management of urinary extravasation in 18 boys with posterior urethral valves.

PURPOSE: Urinary extravasation with associated posterior urethral valves is uncommon and published articles are restricted to case reports. We propose a management algorithm on the basis of presentation of 18 boys with this condition. MATERIALS AND METHODS: In this retrospective review we analyze the clinical features, diagnostic radiological imaging (voiding cystourethrogram and (99m)technetium mercaptoacetyltriglycine scan) and measured glomerular filtration rate (GFR) for assessment of renal function in boys presenting with posterior urethral valves and urinary extravasation. Indications for surgical intervention and long-term outcome were evaluated. Results are presented as mean +/- SD. RESULTS: Patient age at presentation was 4 days (range 1 to 28). Salient features at presentation were abdominal distention in 55.5% of cases, flank mass in 55.5%, respiratory distress in 16.6% and septicemia in 22.2%. Patients were categorized into group 1 with ascites (6 boys) and group 2 without ascites (12). Followup was 70.8 +/- 5.6 months. In group 1 the 3 boys with ascites alone had a followup GFR of 29 versus 74 ml. per minute per 1.73 m.2 in 3 with urinoma plus ascites (p = 0.001) at 64 +/- 4.9 months. In group 2 the GFR in 3 boys with bilateral urinoma was 104.7 +/- 30.4 versus 54.3 +/- 29.4 ml. per minute per 1.73 m.2 in the other 9 with unilateral urinoma (p = 0.001) at 36 +/- 4.2 and 81.3 +/- 4.7 months, respectively. The ipsilateral kidney showed reduced function in 6 of 12 boys with unilateral urinoma from both groups. CONCLUSIONS: Renal function on the side of the urinoma is impaired, and the majority of patients have impaired global renal function. A management algorithm is proposed.

Algorithms↗
PubMed2002

Abdominal sensitivity in the first year of life: comparison of infants with and without prenatally diagnosed unilateral hydronephrosis.

There are few studies on visceral pain in infants, despite its clinical importance. We have used the abdominal skin reflex (ASR) to measure changes in abdominal sensitivity in the presence of visceral pathology in infants. The reflex was elicited by applying calibrated von Frey hairs to each side of the abdomen and the mechanical threshold and the degree of reflex radiation as denoted by hip flexion were measured. The developmental progression of ASR properties during the first year of life was studied in a cross-sectional sample of healthy infants ranging from 30 to 95 weeks postconceptional age (PCA). These properties were compared to those in infants with unilateral hydronephrosis (UH) using a blinded protocol. Infants with UH were studied at their first outpatient appointment after birth, and postoperatively following surgery if this was indicated. The investigators were blinded to laterality and severity of hydronephrosis until data were analysed, or until surgery. A total of 30 patients with UH and 77 healthy infants were included in the study. In 21 (70%) patients, the side of hydronephrosis had a significantly lower ASR threshold than the contralateral side of the abdomen. There was a significant increase in reflex threshold and decrease in reflex radiation with increasing PCA in control infants. However, in UH infants, this relationship did not exist, even on the unaffected side of the abdomen.Our results show that infants with prenatally diagnosed UH demonstrate increased abdominal sensitivity compared with control infants. Using the ASR, we have provided the first evidence of referred visceral hypersensitivity in infants.

Abdomen↗
PubMed2002

Long-term urological outcome of patients presenting with persistent cloaca.

PURPOSE: Persistent cloaca is a complex malformation with variable presentation that remains a difficult reconstructive challenge. Previous reviews have concentrated on surgical technique, and data on long-term outcome are scarce. We evaluate long-term outcome and when possible correlate outcome with anatomy at presentation. MATERIALS AND METHODS: The records and radiographs of 64 patients 0.5 to 25 years old with persistent cloaca treated at 1 institution from 1975 to 2000 were retrospectively reviewed to determine the outcome for urinary and fecal continence. Outcome data were available in 61 girls as 3 died. Of these patients 11 were younger than 3 years, making evaluation of continence difficult, and so the remaining 50 patients constitute the study population. Mean patient age at review was 11.3 years (range 4 to 25). RESULTS: Of the 50 patients 10 (20%) are incontinent of urine (4 with urinary diversion) and 40 (80%) are socially continent, including 11 (22%) who void spontaneously, 6 (12%) who perform clean intermittent catheterization alone and 23 (46%) who underwent reconstructive surgery. Fecal continence was achieved in 30 (60%) of patients and 40% are fecal incontinent or have a stoma. CONCLUSIONS: The majority of patients born with a cloacal malformation can achieve social fecal and urinary control, although in 46% additional reconstructive surgery was required. The presence of a good bladder neck, short common channel, a normal sacrum and 2 normal kidneys indicates improved prognosis for urinary continence. Achieving normal voiding continence in a child with a cloacal malformation still represents an enormous surgical challenge.

Adolescent↗
PubMed2002

Smooth muscle differentiation and cell turnover in mouse detrusor development.

PURPOSE: We systematically analyzed detrusor muscle differentiation in normal mice with a focus on cell turnover (proliferation and apoptosis) as well as on expression of the muscle specific proteins alpha-smooth muscle actin and desmin. MATERIALS AND METHODS: The stages examined were embryonic days 14 and 18, and postnatal day 1 and week 6, representing a period spanning organ inception to postnatal maturity. Alpha-smooth muscle actin, desmin and proliferating cell nuclear antigen were assessed by immunohistochemical testing of whole bladders and Western blot analysis of dissected detrusor layers. Apoptosis was detected in tissue sections by end-labeling. RESULTS: Alpha-smooth muscle actin was expressed by the detrusor layer throughout maturation with levels significantly increasing from embryonic days 14 to 18 and cytoplasmic staining gaining in uniformity postnatally. Desmin expression in the detrusor was insignificant at embryonic day 14 but increased progressively thereafter. Proliferating cell nuclear antigen expression in the detrusor was highest at organ inception and fell stepwise at each developmental stage with low levels postnatally. Apoptosis in the detrusor was only detected at embryonic day 14. CONCLUSIONS: These results demonstrate that morphological growth of the mouse detrusor muscle is accompanied by complex serial changes in the expression of muscle specific proteins and in cell turnover. Strikingly, detrusor muscle cell differentiation and proliferation are inversely related. These detailed studies may serve as a comparison for future experiments involving aberrant mouse bladder development.

Actins↗
PubMed2002

Prenatal diagnosis of cloacal anomalies.

OBJECTIVE: To evaluate prenatal diagnosis in facilitating prenatal counselling and planning optimal perinatal care for persistent cloaca, a complex malformation with variable presentation and a difficult reconstructive challenge for the paediatric urologist and surgeon. PATIENTS AND METHODS: The prenatal records of six patients with a suspected prenatal diagnosis of cloacal anomaly, subsequently confirmed on delivery, were reviewed. All had serial prenatal ultrasonograms. Fetal medicine and paediatric surgical specialists were present for the scans and counselled the parents jointly. RESULTS: The diagnosis was made at 19-33 weeks of gestation; all fetuses had a cystic structure arising from the pelvis and bilateral hydronephrosis, with a poorly visualized fetal bladder in most. Other prenatal features included transient fetal ascites, oligohydramnios, ambiguous genitalia and growth retardation. Female karyotype was confirmed in all cases by amniocentesis. Diagnosis was aided in two patients by fetoscopy and in another by magnetic resonance imaging. CONCLUSIONS: Cloacal anomalies can be diagnosed prenatally and should be considered in any female fetus presenting with bilateral hydronephrosis, a poorly visualized bladder and a cystic lesion arising from the pelvis. Prenatal diagnosis allows time for parental counselling and planning of the delivery at a centre equipped with neonatal intensive-care and paediatric surgical facilities.

Cloaca↗
PubMed2002

Renal outcome in patients with cloaca.

PURPOSE: Cloaca is a complex malformation in which the rectum, vagina and urinary tract open into a single common channel. Functional results after reconstructive surgery have been documented but the renal outcome is less clearly understood. MATERIALS AND METHODS: The records of all patients with cloacal malformation treated at our institution from 1980 to 2000 were retrospectively reviewed to determine the renal outcome. All patients underwent serial ultrasound of the urinary tract, voiding cystography, nuclear renography, lumbosacral radiography, and measurement of serum creatinine and glomerular filtration rate when appropriate. RESULTS: We identified 64 patients 0.5 to 19 years old (mean age 11.2) at the time of the study. Of the 64 patients 53 (83%) were born with a structural abnormality of the urinary tract, including renal dysplasia in 17 (27%), ectopic kidney in 9 (14%), solitary kidney in 8 (13%), duplex kidneys in 6 (9%) and ureteropelvic junction obstruction in 3 (5%). Vesicoureteral reflux was noted in 34 cases (53%) and a sacral abnormality was diagnosed in 36 (57%). The glomerular filtration rate was measured in 38 patients (60%). Chronic renal failure developed in 32 patients (50%) with a glomerular filtration rate of less than 80 ml. per minute per 1.73 m.2, including 11 (17%) who progressed to end stage renal failure, 4 who (6%) required renal transplantation and 4 who died of chronic renal failure. Of the 32 children with a glomerular filtration rate of less than 80 ml. per minute per 1.73 m.2 44% had renal dysplasia, 25% had a solitary kidney, 44% had sacral anomalies, 72% had vesicoureteral reflux and 47% had secondary renal scarring. CONCLUSIONS: Renal impairment causes significant morbidity and mortality in patients with a cloacal malformation. These patients need a complete nephrourological assessment in the neonatal period due to the high incidence of urinary tract and sacral anomalies as well as careful post-reconstruction followup.

Adolescent↗
PubMed2001

Duplex systems.

Duplex kidneys occur in 0.8% of the general population, many of whom are asymptomatic. Children with duplex kidneys may be prone to urinary tract infections because of vesico-ureteric reflux or obstruction. Surgical management is usually required once symptoms occur. Increasing numbers of duplex kidneys are now prenatally diagnosed by ultrasound, resulting in the development of early postnatal strategies to try and reduce morbidity.

Child↗
PubMed2001

The Yang-Monti ileovesicostomy: a problematic channel?

OBJECTIVE: To compare the differences in the quality of Mitrofanoff channels created using appendix and re-tubularized small bowel (the Yang-Monti ileovesicostomy). Patients and methods The case-notes were reviewed retrospectively for all patients who underwent a Mitrofanoff procedure using either appendix or small bowel, over a 5-year period from June 1994 to July 1999. RESULTS: In all, 92 patients underwent 94 Mitrofanoff procedures; the appendix was used in 69 and small bowel in 25. The underlying diagnoses were exstrophy-epispadias complex (38), neuropathic bladder (21), anorectal malformations and cloacal anomalies (15), posterior urethral valves (nine) and miscellaneous (nine). The mean (range) age at operation was 9.2 (1.1-18.3) years. The mean (range) follow-up for the appendix group was 37 (6.7-65) months and for the Monti group 25 (6-66) months. Catheterization problems occurred in 18 (27%) patients from the appendix group; two needed an adjustment of technique, six dilatation and 10 revision. Stomal stenosis occurred in 10 (15%) patients, bladder level stenosis in four (6%) and conduit necrosis in two. Catheterization problems were reported in 15 (60%) patients from the Monti group; five needed revision, three dilatation and seven are being managed conservatively. The incidences of stomal stenosis (four, 16%) and bladder level stenosis (two, 8%) were comparable with the appendix group. In addition, two patients had distal channel (sub-stomal) stenosis and two had mid-channel stenosis. The problem unique to the Yang-Monti channel was a pouch-like dilatation in seven patients (28%), all of whom presented with catheterization problems; five are being managed conservatively and two have needed pouch resection. Stomal prolapse occurred in five (7%) patients in the appendix group, but in none of the Monti group. CONCLUSIONS: The appendix is the conduit of choice for a Mitrofanoff procedure. Re-tubularized small bowel conduits have a considerably higher incidence of catheterization problems. Anatomical factors may contribute to the unique incidence of pouch formation.

Adolescent↗
PubMed2001

Upper pole heminephrectomy: is complete ureterectomy necessary?

OBJECTIVE: To determine the re-operation rate on the distal ureter after upper pole heminephrectomy with incomplete ureterectomy. PATIENTS AND METHODS: The case notes from one institution were reviewed retrospectively; 60 upper pole heminephrectomies with incomplete ureterectomy were undertaken in 39 girls and 16 boys (mean age at primary surgery 27 months, range 3--88). RESULTS: Thirty-two children (58%) had an antenatal diagnosis while 12 (22%) presented with a urinary tract infection (UTI) and six (11%) with urinary incontinence. Twenty-nine of the 60 renal units (48%) had an associated ureterocele and in nine (15%) the ureter was ectopic. Ten infants (18%) underwent initial puncture of a ureterocele. Five patients (8%), all females, required lower urinary tract re-operation. The indications for secondary surgery were recurrent UTIs in all and a prolapsed ureterocele in one. All five had ultrasonographic evidence of a dilated ureteric stump. Reflux into the retained stump was detected in one child. CONCLUSIONS: The re-operation rate for a redundant ureteric stump in this series was 8%. The risk of injury to the good ureter may outweigh the benefits of a complete ureterectomy.

Child↗
PubMed2001

Non-visualisations of the fetal bladder: aetiology and management.

Failure to detect a normally filled fetal bladder on ultrasound scanning can imply the presence of a serious urogenital abnormality. Detailed scanning may elicit the underlying pathology, but there may be complex anomalies present, the full extent of which often has to await the results of postnatal investigations. Management in a combined paediatric urology:fetal medicine clinic is recommended.

Abnormalities, Multiple↗
PubMed1999

Antenatal and perinatal uro-nephrology: current questions and dilemmas.

The development of antenatal ultrasonography and the detection of fetal uropathies has created a new field for paediatric urologists. The embryology and physiology of the fetal renal tract is still poorly understood. It is, however, recognised that delays in the maturation of the renal system can lead to transient dilatation of the urinary tract. Structural and functional anomalies can also result in dilatation, but these are permanent. The ability to distinguish between the transient and permanent impairments to urine flow represents a diagnostic challenge. This review article discusses the pathophysiology of urine flow impairment, antenatal detection and the postnatal management of the common congenital uropathies.

Female↗