Patrick Arthur Dewan - Academia.edu (original) (raw)
Papers by Patrick Arthur Dewan
British Journal of Urology, 1993
The antenatal histories of 42 patients with posterior urethral valves diagnosed between June 1987... more The antenatal histories of 42 patients with posterior urethral valves diagnosed between June 1987 and September 1990 were reviewed. The mothers of all patients had at least one ultrasound scan during pregnancy. Despite this, fetal uropathy was diagnosed in only 19 cases. The remaining 23 undiagnosed children presented acutely, all within the first 6 months of life. In 33 of 36 pregnancies scanned before 24 weeks' gestation, fetal urological pathology was undetected. Mean plasma creatinine (pCr) at presentation in the group antenatally diagnosed was 139 Jlmol/I and in those presenting acutely was 238 Jlmol/1. All pCr analysed were taken after at least 48 h of life. Renal function as measured by follow-up pCr was better in the antenatally diagnosed group during the first year of life. It would appear that a routine second ultrasound scan at 26 weeks' gestation or later would reveal more cases of posterior urethral valves and this information may improve the outcome in terms of renal function.
British Journal of Urology, 1993
Ten lambs had their bladders augmented with de-epithelialised stomach muscle added to an intact u... more Ten lambs had their bladders augmented with de-epithelialised stomach muscle added to an intact urothelium. They were assessed functionally and histologically up to 2 months post-operatively. The urothelium remained viable with minimal inflammation and a neo-bladder with good volume was formed.
Papua and New Guinea medical journal
The posterior sagittal anorectoplasty (PSARP) procedure for the definitive repair of children wit... more The posterior sagittal anorectoplasty (PSARP) procedure for the definitive repair of children with imperforate anus was described in 1982. Unfortunately, surgeons in Papua New Guinea (PNG) have until recently not had the opportunity of being trained in the technique. Through the Medical Officer, Nursing and Allied Health Sciences Training Project (MONAHP) and Pacific Islands Project (PIP) of the Royal Australasian College of Surgeons, 65 Papua New Guinean children with an anorectal anomaly have undergone a repair, in conjunction with training of the surgical staff and medical students. A new technique for the management of a prolapsed colostomy has been developed and a protocol for management of PSARP patients postoperatively has been formulated. Patients referred to the paediatric surgical visiting teams were diagnosed and treated according to the stage their management had reached. Patients with a low anomaly were treated by a cutback procedure, those with a colostomy and a high l...
Urology, 2002
To analyze the relationship between hydronephrosis due to urinary tract obstruction and the prese... more To analyze the relationship between hydronephrosis due to urinary tract obstruction and the presence of the sonographic eggshell sign, which is a recently described crescent of increased echogenicity at the caliceal/parenchymal interface and possibly an indicator of raised intrarenal pressure. All patients presenting between 1996 and 1999 for surgical management of pelviureteral junction obstruction or congenital posterior urethral obstruction had films reviewed for the presence of the eggshell sign. Of 94 patients, 40 presented postnatally and 54 had hydronephrosis detected on the antenatal ultrasound scan. Of the postnatal group, 16 (40%) had urethral obstruction, of whom 4 (25%) displayed the eggshell sign; in the 24 with pelviureteral junction obstruction, the echogenic pericaliceal crescent was seen in 5 (20.8%). Of the 54 in the prenatal group, 8 (15.4%) were found to have urethral obstruction, 5 (62.5%) of whom demonstrated the eggshell sign. Of the 46 prenatally diagnosed patients with pelviureteral junction obstruction, 31 (70.5%) displayed the eggshell sign before birth; we were unable to satisfactorily review 2 patients' ultrasound scans. Antenatally diagnosed hydronephrosis due to significant urinary tract obstruction seems to be related to the appearance of the eggshell sign on ultrasonography, particularly in those patients with pelviureteral junction obstruction. Those patients without significant caliceal distension and those with renal dysplasia or severe hydronephrosis with low-pressure kidneys were less likely to display the eggshell sign. Although the association with other causes of hydronephrosis is unknown, we believe these figures support the need for further investigation of the eggshell sign as a marker of raised intrarenal pressure to possibly provide another data point in the sonographic evaluation of congenital hydronephrosis.
Pediatric Surgery International, 1995
Over a 3-year period 128 boys had endoscopic video recording; 29 were found to have a localized c... more Over a 3-year period 128 boys had endoscopic video recording; 29 were found to have a localized constriction of the bulbar urethra. Three had significant narrowing, 11 had a moderate change in lumenal diameter, and 15 had a minor indentation. Three boys had a membranous obstruction, 21 had a lesion that changed appearance during the endoscopy, consistent with contracting muscle,
Pediatric Surgery International, 1993
Young's classification of urethral valves has been challenged by endoscopic and post-mortem evide... more Young's classification of urethral valves has been challenged by endoscopic and post-mortem evidence, but as yet has not been abandoned. A recent review of Young's original work, which also reported conversion of type III valves to type I, identified a need to reassess the morphology of congenital posterior urethral obstruction. These seven cases support the contention that there is a common morphology for most boys with congenital obstruction of the posterior urethra.
Pediatric Surgery International, 1988
... Testicular teratoma and diastematomyelia in a boy with Klinefelter's syndrome Duncan Mac... more ... Testicular teratoma and diastematomyelia in a boy with Klinefelter's syndrome Duncan MacGregor 1 and Paddy Dewan 2 ... The authors would like to thank Dr. PE Campbell, Dr. M. de Campo, Mr. D. Wallace, and Mr. R. Fowler for their assistance with this case report. References ...
Pediatric Surgery International, 1988
A boy with Fabry's disease (alpha-galactosidase A deficiency) who developed priapism as a complic... more A boy with Fabry's disease (alpha-galactosidase A deficiency) who developed priapism as a complication of this disorder is presented.
Pathology, 1993
Xanthogranulomatous pyelonephritis (XGP) is an unusual chronic inflammatory condition which most ... more Xanthogranulomatous pyelonephritis (XGP) is an unusual chronic inflammatory condition which most often affects women in their 5th to 7th decades and is rare in infants. Predisposing factors include infection, calculi and obstructive uropathy. We have reviewed the surgical files of 4 cases seen over a 28 yr period from 1964-91. All of the 3 partial and one total nephrectomy specimens demonstrated typical features of XGP with renal parenchyma effaced by a mixed acute and chronic inflammatory infiltrate which included prominent aggregates of foamy histiocytes containing eosinophilic inclusions. No Michaelis-Gutmann bodies were seen. This study shows the association of XGP with chronic infection, anatomical malformation and reflux in infancy, and raises the possibility of a temporary altered immune response in its pathogenesis.
Journal of Pediatric Surgery, 2003
The aim of this study was to report the results of 32 cases of dilatation of urethral stricture u... more The aim of this study was to report the results of 32 cases of dilatation of urethral stricture using a guide wire and sheath dilator technique supplemented by clean intermittent catheterization if further stabilization of the urethral stricture was felt warranted. Methods: The procedure involves insertion of a straight flexi-tip lubricated guide wire through the urethral stricture under cystoscopic guidance followed by insertion of a series of sheath dilators. Dilatation was followed by insertion of a Foley catheter, which was left in situ for 1 to 3 days. Patients underwent repeat cystoscopy to evaluate the urethra for recurrent stricture and those with a recalcitrant stricture were commenced on clean intermittent catheterization (CIC) to stabilize the narrowing. Results: Thirty-two patients were included. They have been followed up for up to 2 1 ⁄2 years after their last cystoscopy (mean, 16 months). Thirteen of 32 patients had more than 4 dilatations under anesthesia. Twelve patients had undergone CIC postoperatively. Complications included a urinary tract infection in 3 boys and bladder spasms in one. No false passage or sepsis occurred with this approach. Conclusions: Guide wire-assisted urethral dilatation helps avoid risks associated with blind dilatation techniques and appears to be a safe and simple alternative for management of urethral strictures in pediatric urology.
Journal of Pediatric Surgery, 2001
Five infants with giant omphalocele had persistent collapse of the left lung and required prolong... more Five infants with giant omphalocele had persistent collapse of the left lung and required prolonged respiratory support. Narrowing of the left main bronchus, reversible with positive end-expiratory pressure, was identified radiographically in 3 infants, and we postulate that this relates to distortion of the bronchus within the constraints of the elongated, narrow thoracic cavity characteristic of these patients. The lung collapse may be precipitated by manipulation (reduction or attempted reduction) of the omphalocele.
Journal of Paediatrics and Child Health, 1998
To ascertain the age distribution of the different pathological mechanisms which lead to the deve... more To ascertain the age distribution of the different pathological mechanisms which lead to the development of pelviureteric junction obstruction. A series of 165 kidneys in 158 children who underwent pyeloplasty for pelviureteric junction obstruction were reviewed. Those 132 renal units (127 children) with uncomplicated pathology were selected for further study. The operative records were reviewed for the underlying cause of obstruction and the age at operation. Obstruction due to extrinsic compression by an aberrant lower pole vessel occurred in an older group (median age 67.3 mo) than those with a narrowing or angulation of the pelviureteric junction (median age 3.1 mo). Pelviureteric junction obstruction, secondary to a lower pole vessel presents at an older age. Doppler ultrasonography to detect a lower pole vessel may be of benefit in the management of equivocal cases of pelviureteric junction obstruction, particularly in prenatally diagnosed hydronephrosis.
Journal of Paediatrics and Child Health, 1994
A case of neonatal adrenal haemorrhage presenting as a unilateral acute scrotum is reported, and ... more A case of neonatal adrenal haemorrhage presenting as a unilateral acute scrotum is reported, and the role of ultrasound (US) examination in diagnosis is discussed.
British Journal of Urology, 1992
Summary— Congenital obstruction of the posterior urethra was first systematically classified by Y... more Summary— Congenital obstruction of the posterior urethra was first systematically classified by Young in 1919. Since then, no‐one has seriously challenged the presence of both Type I and Type III “valves”, although the presence of Type II lesions has often been disputed. A review of Young's papers and more recent anatomical studies, together with endoscopic findings in our own patients, indicates that most congenital posterior urethral obstructions are anatomically similar. Consequently, Young's classification now seems redundant.
BJU International, 2001
The indications for ureterocystoplasty include a variety of conditions associated with a common t... more The indications for ureterocystoplasty include a variety of conditions associated with a common theme, i.e. low bladder capacity, poor compliance and raised intravesical pressure. The aetiology of bladder dysfunction can include posterior urethral obstruction [1±5], bladder exstrophy [6], a neuropathic bladder [2,4±6] and ureteric duplication with re ̄ux [2,7], all of which are not infrequently associated with poor renal function and massively dilated, re ̄uxing ureters. Often only one kidney is adversely affected, a phenomenon which has been described as the `pop-off ' or VURD syndrome (unilateral VUR and renal dysplasia) [8]. In the VURD syndrome unilateral VUR appears to allow the ipsilateral ureter and its pelvicalyceal system to act as an expansive reservoir, preventing contralateral VUR and renal damage, by lowering the bladder pressure [9]. Occasionally the dilated poorly functioning system leads to persistent UTI, suggesting the need for a nephroureterectomy. However, removing the pressure-reducing re ̄uxing unit may lead to a deterioration in function of the remaining kidney, or of a transplant kidney. This deterioration may be prevented by bladder augmentation, which reduces bladder pressure. Traditionally the bladder has been augmented with a segment of small or large bowel, the complications of which have been increasingly recognized, including excessive mucus formation, calculi, dysplasia and malignancy, metabolic acidosis, and abnormalities of calcium metabolism [10±12]. There are signi®cant complications also when the stomach is chosen as the source of augmenting tissue, i.e. haematuria-dysuria, metabolic alkalosis and hypergastrinaemia [13±15]. Several techniques have been suggested which produce a urothelial-lined reservoir, none of which has gained universal acceptance. Urothelial grafting onto denuded bowel muscle with either harvested urothelium [16], or cultured cells, has not been applied to patients [17]. Autoaugmentation, in which the detrusor is incised, leaving a wide-mouthed diverticulum, may not provide a permanent solution for a suf®cient proportion of patients [18]. Diverticulocystoplasty is only applicable to patients with very large bladder diverticula [19]. A demucosalized enterocystoplasty has been used in many animal models [20±22], but in only a few patients [23]. The success of the use of demucosalized segments of bowel is marred by the re-growth of the bowel epithelium, if the submucosa is not removed, or potential infarction of the muscle if the submucosa is taken off [21]. However, good results have been reported for autoaugmentation colocystoplasty. Another alternative, autoaugmentation gastrocystoplasty, uses a de-epithelialized segment of stomach, which seems more able to tolerate the removal of the mucosa than the colon or small bowel. The gastric muscle patch is then added to an autoaugmented bladder; as yet the technique has only been reported in a few patients, but good results have been recorded [24,25]. The use of the ureter in bladder augmentation provides a urothelial-lined neobladder with all the appropriate histological layers, and therefore ureterocystoplasty has become favoured, particularly when there is high-grade VUR [1,2,4,6,26±29]. Of the many patients with ureterocystoplasty thus far described, several have been aged f2 years, indicating the applicability to younger children [1,2,4,6,26,27,29], whereas ileocystoplasty and gastrocystoplasty are rarely considered appropriate in the very young, although they have been used [30,31]. Given the de®ciencies of the other currently available urothelial-lined techniques, it would appear that ureterocystoplasty is ideal for patients with appropriately enlarged ureters. The technique has the added advantage in the female population that there is no pedicle to interfere with either expansion of the uterus during pregnancy, nor a risk from division during a Caesarian section. The more recent development of a wholly extraperitoneal ureterocystoplasty (with or without transuretero-ureterostomy for renal preservation) adds several additional advantages. By maintaining the integrity of the peritoneal cavity the risk of both ventriculo-peritoneal shunt infection and subsequent Accepted for publication 15 August 2001 BJU International (2001), 88, 744±751
BJU International, 2002
Objective To review the ultrasonography of patients who had undergone pyeloplasty for pelvi-urete... more Objective To review the ultrasonography of patients who had undergone pyeloplasty for pelvi-ureteric junction (PUJ) obstruction, and document the changes in calyceal distension and parenchymal thickness after pyeloplasty, to attempt to establish an additional prognostic indicator. Patients and methods Fifty-eight patients who underwent pyeloplasty for PUJ obstruction were assessed retrospectively. Pre-and postoperative ultrasonograms were analysed for both pyelocaliectasis, graded according to the Society for Fetal Urology criteria, and the ratio of the depth of calyces to the thickness of the parenchyma (C/P ratio). Patients underwent nuclear medicine renography before and 3 months after pyeloplasty. The results were analysed using the paired t-test, Kruskal±Wallis test, Spearman's correlation coef®cient by rank test and the Mann-Whitney U-test. Results There was no signi®cant difference in hydronephrosis grade before and after surgery (P<0.05) but there was a signi®cant difference in the C/P ratios (P<0.01). There was no correlation between C/P ratios and the results of diuresis renography. Conclusion Hydronephrosis as measured by an estimate of pelvic volume is an insensitive marker of improvement after pyeloplasty. Reduced calyceal distension correlates well with other favourable prognostic indicators. Therefore, the C/P ratio may be an additional indicator of the appropriateness of surgical intervention, and should be the subject of further study.
British Journal of Urology, 1992
Summary— Injectable polytetrafluoroethylene (Polytef) has been used in many patients for vocal co... more Summary— Injectable polytetrafluoroethylene (Polytef) has been used in many patients for vocal cord augmentation and for the management of urinary incontinence since the early 1960s and noninjectable forms have been used for sutures, hernia repair, replacement of the stapes, hip prostheses, cardiac valves and vascular grafts.Since 1984, many children have been treated with subureteric Polytef injection for the management of vesicoureteric reflux. Its use in young patients has heightened the concern about particle migration and carcinogenesis, particularly in view of the fact that the substance may be in the patient for decades.The available evidence does not confirm a significant carcinogenic effect in humans; rather it suggests that, if there is a risk, it is extremely low. However, human specimens, taken decades after the implantation of Polytef, and long‐term, non‐rodent animal experiments are needed to substantiate the probable safety of Polytef in children.
BJU International, 2001
Objective To assess the clinical and radiological spectrum in boys with endoscopically severe pos... more Objective To assess the clinical and radiological spectrum in boys with endoscopically severe posterior urethral obstruction, as there is a broad clinical spectrum which does not always correlate with the cystoscopic ®ndings. Patients and methods Between December 1990 and July 2000, 39 boys (newborn to 12 years old) underwent cystoscopy to investigate a urethral anomaly and were found to have a severe obstructing posterior urethral membrane. Their voiding cystograms, video-recorded cystoscopy and presenting signs were reviewed. Results Of the 39 boys assessed, a voiding cystogram and presenting signs were available in 36. Of these 36 boys, three cystograms were initially reported as normal, eight showed posterior urethral dilatation as the only feature, and the remainder had more severe bladder and upper tract changes. Fourteen were diagnosed after identifying antenatal hydronephrosis, four presented with voiding dysfunction, one with haematuria and 17 were found after investigation of a urinary tract infection. Conclusions This study shows that a congenital posterior urethral membrane that has only a small posterior defect endoscopically can have a wide clinical and radiological spectrum. The difference in outcome may be caused by variations in the response of the bladder to the obstruction, resulting in a different effect on the upper tracts. Keywords posterior urethral valves, congenital obstructive posterior urethral membrane (COPUM), cystoscopy, cysto-urethrogram
Indicates that injections under the ureteric orifice can cure VUR and that the tissue response to... more Indicates that injections under the ureteric orifice can cure VUR and that the tissue response to the plastics becomes quiescent. Research into embolisation from solid implants from intravenous tubing and the possibility of antibody formation to implanted plastics is also included. A ...
ANZ Journal of Surgery, 2001
British Journal of Urology, 1993
The antenatal histories of 42 patients with posterior urethral valves diagnosed between June 1987... more The antenatal histories of 42 patients with posterior urethral valves diagnosed between June 1987 and September 1990 were reviewed. The mothers of all patients had at least one ultrasound scan during pregnancy. Despite this, fetal uropathy was diagnosed in only 19 cases. The remaining 23 undiagnosed children presented acutely, all within the first 6 months of life. In 33 of 36 pregnancies scanned before 24 weeks' gestation, fetal urological pathology was undetected. Mean plasma creatinine (pCr) at presentation in the group antenatally diagnosed was 139 Jlmol/I and in those presenting acutely was 238 Jlmol/1. All pCr analysed were taken after at least 48 h of life. Renal function as measured by follow-up pCr was better in the antenatally diagnosed group during the first year of life. It would appear that a routine second ultrasound scan at 26 weeks' gestation or later would reveal more cases of posterior urethral valves and this information may improve the outcome in terms of renal function.
British Journal of Urology, 1993
Ten lambs had their bladders augmented with de-epithelialised stomach muscle added to an intact u... more Ten lambs had their bladders augmented with de-epithelialised stomach muscle added to an intact urothelium. They were assessed functionally and histologically up to 2 months post-operatively. The urothelium remained viable with minimal inflammation and a neo-bladder with good volume was formed.
Papua and New Guinea medical journal
The posterior sagittal anorectoplasty (PSARP) procedure for the definitive repair of children wit... more The posterior sagittal anorectoplasty (PSARP) procedure for the definitive repair of children with imperforate anus was described in 1982. Unfortunately, surgeons in Papua New Guinea (PNG) have until recently not had the opportunity of being trained in the technique. Through the Medical Officer, Nursing and Allied Health Sciences Training Project (MONAHP) and Pacific Islands Project (PIP) of the Royal Australasian College of Surgeons, 65 Papua New Guinean children with an anorectal anomaly have undergone a repair, in conjunction with training of the surgical staff and medical students. A new technique for the management of a prolapsed colostomy has been developed and a protocol for management of PSARP patients postoperatively has been formulated. Patients referred to the paediatric surgical visiting teams were diagnosed and treated according to the stage their management had reached. Patients with a low anomaly were treated by a cutback procedure, those with a colostomy and a high l...
Urology, 2002
To analyze the relationship between hydronephrosis due to urinary tract obstruction and the prese... more To analyze the relationship between hydronephrosis due to urinary tract obstruction and the presence of the sonographic eggshell sign, which is a recently described crescent of increased echogenicity at the caliceal/parenchymal interface and possibly an indicator of raised intrarenal pressure. All patients presenting between 1996 and 1999 for surgical management of pelviureteral junction obstruction or congenital posterior urethral obstruction had films reviewed for the presence of the eggshell sign. Of 94 patients, 40 presented postnatally and 54 had hydronephrosis detected on the antenatal ultrasound scan. Of the postnatal group, 16 (40%) had urethral obstruction, of whom 4 (25%) displayed the eggshell sign; in the 24 with pelviureteral junction obstruction, the echogenic pericaliceal crescent was seen in 5 (20.8%). Of the 54 in the prenatal group, 8 (15.4%) were found to have urethral obstruction, 5 (62.5%) of whom demonstrated the eggshell sign. Of the 46 prenatally diagnosed patients with pelviureteral junction obstruction, 31 (70.5%) displayed the eggshell sign before birth; we were unable to satisfactorily review 2 patients' ultrasound scans. Antenatally diagnosed hydronephrosis due to significant urinary tract obstruction seems to be related to the appearance of the eggshell sign on ultrasonography, particularly in those patients with pelviureteral junction obstruction. Those patients without significant caliceal distension and those with renal dysplasia or severe hydronephrosis with low-pressure kidneys were less likely to display the eggshell sign. Although the association with other causes of hydronephrosis is unknown, we believe these figures support the need for further investigation of the eggshell sign as a marker of raised intrarenal pressure to possibly provide another data point in the sonographic evaluation of congenital hydronephrosis.
Pediatric Surgery International, 1995
Over a 3-year period 128 boys had endoscopic video recording; 29 were found to have a localized c... more Over a 3-year period 128 boys had endoscopic video recording; 29 were found to have a localized constriction of the bulbar urethra. Three had significant narrowing, 11 had a moderate change in lumenal diameter, and 15 had a minor indentation. Three boys had a membranous obstruction, 21 had a lesion that changed appearance during the endoscopy, consistent with contracting muscle,
Pediatric Surgery International, 1993
Young's classification of urethral valves has been challenged by endoscopic and post-mortem evide... more Young's classification of urethral valves has been challenged by endoscopic and post-mortem evidence, but as yet has not been abandoned. A recent review of Young's original work, which also reported conversion of type III valves to type I, identified a need to reassess the morphology of congenital posterior urethral obstruction. These seven cases support the contention that there is a common morphology for most boys with congenital obstruction of the posterior urethra.
Pediatric Surgery International, 1988
... Testicular teratoma and diastematomyelia in a boy with Klinefelter's syndrome Duncan Mac... more ... Testicular teratoma and diastematomyelia in a boy with Klinefelter's syndrome Duncan MacGregor 1 and Paddy Dewan 2 ... The authors would like to thank Dr. PE Campbell, Dr. M. de Campo, Mr. D. Wallace, and Mr. R. Fowler for their assistance with this case report. References ...
Pediatric Surgery International, 1988
A boy with Fabry's disease (alpha-galactosidase A deficiency) who developed priapism as a complic... more A boy with Fabry's disease (alpha-galactosidase A deficiency) who developed priapism as a complication of this disorder is presented.
Pathology, 1993
Xanthogranulomatous pyelonephritis (XGP) is an unusual chronic inflammatory condition which most ... more Xanthogranulomatous pyelonephritis (XGP) is an unusual chronic inflammatory condition which most often affects women in their 5th to 7th decades and is rare in infants. Predisposing factors include infection, calculi and obstructive uropathy. We have reviewed the surgical files of 4 cases seen over a 28 yr period from 1964-91. All of the 3 partial and one total nephrectomy specimens demonstrated typical features of XGP with renal parenchyma effaced by a mixed acute and chronic inflammatory infiltrate which included prominent aggregates of foamy histiocytes containing eosinophilic inclusions. No Michaelis-Gutmann bodies were seen. This study shows the association of XGP with chronic infection, anatomical malformation and reflux in infancy, and raises the possibility of a temporary altered immune response in its pathogenesis.
Journal of Pediatric Surgery, 2003
The aim of this study was to report the results of 32 cases of dilatation of urethral stricture u... more The aim of this study was to report the results of 32 cases of dilatation of urethral stricture using a guide wire and sheath dilator technique supplemented by clean intermittent catheterization if further stabilization of the urethral stricture was felt warranted. Methods: The procedure involves insertion of a straight flexi-tip lubricated guide wire through the urethral stricture under cystoscopic guidance followed by insertion of a series of sheath dilators. Dilatation was followed by insertion of a Foley catheter, which was left in situ for 1 to 3 days. Patients underwent repeat cystoscopy to evaluate the urethra for recurrent stricture and those with a recalcitrant stricture were commenced on clean intermittent catheterization (CIC) to stabilize the narrowing. Results: Thirty-two patients were included. They have been followed up for up to 2 1 ⁄2 years after their last cystoscopy (mean, 16 months). Thirteen of 32 patients had more than 4 dilatations under anesthesia. Twelve patients had undergone CIC postoperatively. Complications included a urinary tract infection in 3 boys and bladder spasms in one. No false passage or sepsis occurred with this approach. Conclusions: Guide wire-assisted urethral dilatation helps avoid risks associated with blind dilatation techniques and appears to be a safe and simple alternative for management of urethral strictures in pediatric urology.
Journal of Pediatric Surgery, 2001
Five infants with giant omphalocele had persistent collapse of the left lung and required prolong... more Five infants with giant omphalocele had persistent collapse of the left lung and required prolonged respiratory support. Narrowing of the left main bronchus, reversible with positive end-expiratory pressure, was identified radiographically in 3 infants, and we postulate that this relates to distortion of the bronchus within the constraints of the elongated, narrow thoracic cavity characteristic of these patients. The lung collapse may be precipitated by manipulation (reduction or attempted reduction) of the omphalocele.
Journal of Paediatrics and Child Health, 1998
To ascertain the age distribution of the different pathological mechanisms which lead to the deve... more To ascertain the age distribution of the different pathological mechanisms which lead to the development of pelviureteric junction obstruction. A series of 165 kidneys in 158 children who underwent pyeloplasty for pelviureteric junction obstruction were reviewed. Those 132 renal units (127 children) with uncomplicated pathology were selected for further study. The operative records were reviewed for the underlying cause of obstruction and the age at operation. Obstruction due to extrinsic compression by an aberrant lower pole vessel occurred in an older group (median age 67.3 mo) than those with a narrowing or angulation of the pelviureteric junction (median age 3.1 mo). Pelviureteric junction obstruction, secondary to a lower pole vessel presents at an older age. Doppler ultrasonography to detect a lower pole vessel may be of benefit in the management of equivocal cases of pelviureteric junction obstruction, particularly in prenatally diagnosed hydronephrosis.
Journal of Paediatrics and Child Health, 1994
A case of neonatal adrenal haemorrhage presenting as a unilateral acute scrotum is reported, and ... more A case of neonatal adrenal haemorrhage presenting as a unilateral acute scrotum is reported, and the role of ultrasound (US) examination in diagnosis is discussed.
British Journal of Urology, 1992
Summary— Congenital obstruction of the posterior urethra was first systematically classified by Y... more Summary— Congenital obstruction of the posterior urethra was first systematically classified by Young in 1919. Since then, no‐one has seriously challenged the presence of both Type I and Type III “valves”, although the presence of Type II lesions has often been disputed. A review of Young's papers and more recent anatomical studies, together with endoscopic findings in our own patients, indicates that most congenital posterior urethral obstructions are anatomically similar. Consequently, Young's classification now seems redundant.
BJU International, 2001
The indications for ureterocystoplasty include a variety of conditions associated with a common t... more The indications for ureterocystoplasty include a variety of conditions associated with a common theme, i.e. low bladder capacity, poor compliance and raised intravesical pressure. The aetiology of bladder dysfunction can include posterior urethral obstruction [1±5], bladder exstrophy [6], a neuropathic bladder [2,4±6] and ureteric duplication with re ̄ux [2,7], all of which are not infrequently associated with poor renal function and massively dilated, re ̄uxing ureters. Often only one kidney is adversely affected, a phenomenon which has been described as the `pop-off ' or VURD syndrome (unilateral VUR and renal dysplasia) [8]. In the VURD syndrome unilateral VUR appears to allow the ipsilateral ureter and its pelvicalyceal system to act as an expansive reservoir, preventing contralateral VUR and renal damage, by lowering the bladder pressure [9]. Occasionally the dilated poorly functioning system leads to persistent UTI, suggesting the need for a nephroureterectomy. However, removing the pressure-reducing re ̄uxing unit may lead to a deterioration in function of the remaining kidney, or of a transplant kidney. This deterioration may be prevented by bladder augmentation, which reduces bladder pressure. Traditionally the bladder has been augmented with a segment of small or large bowel, the complications of which have been increasingly recognized, including excessive mucus formation, calculi, dysplasia and malignancy, metabolic acidosis, and abnormalities of calcium metabolism [10±12]. There are signi®cant complications also when the stomach is chosen as the source of augmenting tissue, i.e. haematuria-dysuria, metabolic alkalosis and hypergastrinaemia [13±15]. Several techniques have been suggested which produce a urothelial-lined reservoir, none of which has gained universal acceptance. Urothelial grafting onto denuded bowel muscle with either harvested urothelium [16], or cultured cells, has not been applied to patients [17]. Autoaugmentation, in which the detrusor is incised, leaving a wide-mouthed diverticulum, may not provide a permanent solution for a suf®cient proportion of patients [18]. Diverticulocystoplasty is only applicable to patients with very large bladder diverticula [19]. A demucosalized enterocystoplasty has been used in many animal models [20±22], but in only a few patients [23]. The success of the use of demucosalized segments of bowel is marred by the re-growth of the bowel epithelium, if the submucosa is not removed, or potential infarction of the muscle if the submucosa is taken off [21]. However, good results have been reported for autoaugmentation colocystoplasty. Another alternative, autoaugmentation gastrocystoplasty, uses a de-epithelialized segment of stomach, which seems more able to tolerate the removal of the mucosa than the colon or small bowel. The gastric muscle patch is then added to an autoaugmented bladder; as yet the technique has only been reported in a few patients, but good results have been recorded [24,25]. The use of the ureter in bladder augmentation provides a urothelial-lined neobladder with all the appropriate histological layers, and therefore ureterocystoplasty has become favoured, particularly when there is high-grade VUR [1,2,4,6,26±29]. Of the many patients with ureterocystoplasty thus far described, several have been aged f2 years, indicating the applicability to younger children [1,2,4,6,26,27,29], whereas ileocystoplasty and gastrocystoplasty are rarely considered appropriate in the very young, although they have been used [30,31]. Given the de®ciencies of the other currently available urothelial-lined techniques, it would appear that ureterocystoplasty is ideal for patients with appropriately enlarged ureters. The technique has the added advantage in the female population that there is no pedicle to interfere with either expansion of the uterus during pregnancy, nor a risk from division during a Caesarian section. The more recent development of a wholly extraperitoneal ureterocystoplasty (with or without transuretero-ureterostomy for renal preservation) adds several additional advantages. By maintaining the integrity of the peritoneal cavity the risk of both ventriculo-peritoneal shunt infection and subsequent Accepted for publication 15 August 2001 BJU International (2001), 88, 744±751
BJU International, 2002
Objective To review the ultrasonography of patients who had undergone pyeloplasty for pelvi-urete... more Objective To review the ultrasonography of patients who had undergone pyeloplasty for pelvi-ureteric junction (PUJ) obstruction, and document the changes in calyceal distension and parenchymal thickness after pyeloplasty, to attempt to establish an additional prognostic indicator. Patients and methods Fifty-eight patients who underwent pyeloplasty for PUJ obstruction were assessed retrospectively. Pre-and postoperative ultrasonograms were analysed for both pyelocaliectasis, graded according to the Society for Fetal Urology criteria, and the ratio of the depth of calyces to the thickness of the parenchyma (C/P ratio). Patients underwent nuclear medicine renography before and 3 months after pyeloplasty. The results were analysed using the paired t-test, Kruskal±Wallis test, Spearman's correlation coef®cient by rank test and the Mann-Whitney U-test. Results There was no signi®cant difference in hydronephrosis grade before and after surgery (P<0.05) but there was a signi®cant difference in the C/P ratios (P<0.01). There was no correlation between C/P ratios and the results of diuresis renography. Conclusion Hydronephrosis as measured by an estimate of pelvic volume is an insensitive marker of improvement after pyeloplasty. Reduced calyceal distension correlates well with other favourable prognostic indicators. Therefore, the C/P ratio may be an additional indicator of the appropriateness of surgical intervention, and should be the subject of further study.
British Journal of Urology, 1992
Summary— Injectable polytetrafluoroethylene (Polytef) has been used in many patients for vocal co... more Summary— Injectable polytetrafluoroethylene (Polytef) has been used in many patients for vocal cord augmentation and for the management of urinary incontinence since the early 1960s and noninjectable forms have been used for sutures, hernia repair, replacement of the stapes, hip prostheses, cardiac valves and vascular grafts.Since 1984, many children have been treated with subureteric Polytef injection for the management of vesicoureteric reflux. Its use in young patients has heightened the concern about particle migration and carcinogenesis, particularly in view of the fact that the substance may be in the patient for decades.The available evidence does not confirm a significant carcinogenic effect in humans; rather it suggests that, if there is a risk, it is extremely low. However, human specimens, taken decades after the implantation of Polytef, and long‐term, non‐rodent animal experiments are needed to substantiate the probable safety of Polytef in children.
BJU International, 2001
Objective To assess the clinical and radiological spectrum in boys with endoscopically severe pos... more Objective To assess the clinical and radiological spectrum in boys with endoscopically severe posterior urethral obstruction, as there is a broad clinical spectrum which does not always correlate with the cystoscopic ®ndings. Patients and methods Between December 1990 and July 2000, 39 boys (newborn to 12 years old) underwent cystoscopy to investigate a urethral anomaly and were found to have a severe obstructing posterior urethral membrane. Their voiding cystograms, video-recorded cystoscopy and presenting signs were reviewed. Results Of the 39 boys assessed, a voiding cystogram and presenting signs were available in 36. Of these 36 boys, three cystograms were initially reported as normal, eight showed posterior urethral dilatation as the only feature, and the remainder had more severe bladder and upper tract changes. Fourteen were diagnosed after identifying antenatal hydronephrosis, four presented with voiding dysfunction, one with haematuria and 17 were found after investigation of a urinary tract infection. Conclusions This study shows that a congenital posterior urethral membrane that has only a small posterior defect endoscopically can have a wide clinical and radiological spectrum. The difference in outcome may be caused by variations in the response of the bladder to the obstruction, resulting in a different effect on the upper tracts. Keywords posterior urethral valves, congenital obstructive posterior urethral membrane (COPUM), cystoscopy, cysto-urethrogram
Indicates that injections under the ureteric orifice can cure VUR and that the tissue response to... more Indicates that injections under the ureteric orifice can cure VUR and that the tissue response to the plastics becomes quiescent. Research into embolisation from solid implants from intravenous tubing and the possibility of antibody formation to implanted plastics is also included. A ...
ANZ Journal of Surgery, 2001