Kevin C. Pringle

The pathogenesis of dysplastic kidney in a urinary tract obstruction in the female fetal lamb

BACKGROUND/PURPOSEnThe type of renal dysplasia resulting from obstructive uropathy depends on the completeness of the obstruction and its timing with respect to the stage of glomerulogenesis at the time of the obstruction. The authors created a successful obstructive uropathy model in the female fetal lamb to demonstrate the differing pathogenesis of renal dysplasia.nnnMETHODSnFemale fetal lambs at 60 and 90 days gestation had their urethra and urachus ligated transabdominally and were delivered by cesarean section at 145 days (full term). Kidney length and cortical thickness were measured, and samples were examined histologically. In the lambs operated on at 90 days, the urine was collected at delivery and Na and CI were measured and compared with the results obtained from normal full-term lambs.nnnRESULTSnSeven of 10 female lambs had hydronephrosis or dysplastic kidneys. The cortext to kidney length ratio was 10+/-3% in the 90-days hydronephrotic group versus 29+/-6% in the controls (P<.001). Morphologically, the 90-day model had dilatation of the collecting tubules with normal glomerular numbers. The 60-day model had tubular cysts with fibromuscular cuffing and reduced glomerular numbers. The fetal urine Na was 47+/-3.3 mmol/L in controls versus 78+/-24 mmol/L in the hydropnephrotic lambs (P<.05). The urine CI in these lambs was 38+/-8.6 mmol/L in controls versus 55+/-14.5 mmol/L in the hydronephrotic lambs (P<.05).nnnCONCLUSIONSnAn obstructive uropathy model was created in female fetal lambs. There were no dysplastic changes in the kidneys in lambs operated on at 90 days gestation, but there were definite dysplastic changes in those operated on at 60 days. Concentrations of Na and CI in the fetal urine are higher than normal in the 90-day model.

Magnetic resonance imaging as an adjunct to planning an anorectal pull-through

Magnetic resonance imaging (MRI) is a relatively new diagnostic tool that generates images of sections of the body taken in any plane. We report the use of MRI as a tool to plan surgical procedures in patients with imperforate anus, imaging the pelvis and lumbosacral spine in the sagittal, transverse, and coronal planes. MRI clearly reveals the extent of the pelvic musculature even in patients with severe sacral agenesis. MRI is extremely useful in assessing patients under consideration for reoperation, clearly demonstrating the relationship between the pulled through colon and the striated muscle complex. A very useful addition is the ability, on the same study, to detect previously unsuspected anomalies such as tethered cord, lipoma of the filum terminale, and renal dysplasia. We conclude that MRI is a very useful examination in selected patients with imperforate anus.

Early bladder wall changes after creation of obstructive uropathy in the fetal lamb

Vesico-amniotic shunting of obstructive uropathy in fetal lambs produced a thick-walled, poorly compliant bladder. We report the early histological changes in the obstructed bladder wall. We created an obstructive uropathy in fetal lambs at 60xa0days gestation by ligating the urethra and urachus. Vesicostomy or vesico-amniotic shunt tube insertion and biopsy of the bladder wall were performed 21xa0days later. The fetuses were delivered at term (145xa0days) and the kidneys and bladder sampled for histology. Colloidal iron (Col Fe), and alpha-smooth muscle actin (α-SMA) immunohistochemical stains were used for these samples. Seventeen fetuses were shunted with 15 biopsies taken at that time. Six (shunt failure or missed urachal ligation) were excluded. All biopsies taken at shunting had positive Col Fe and α-SMA. Term lambs had mild multicystic dysplastic kidney (MCDK) in five, severe MCDK in two, and hydronephrosis in four. All bladders had small volume and were severely fibrotic. Fetal shunt operations 3xa0weeks after the creation of obstructive uropathy provided partial preservation of renal histology but did not preserve normal bladder histology. We suggest that the high hyaluronic acid synthesis activity or hyperplasia of the myofibroblasts in the dilated fetal bladder wall at the time of shunting results in irreversible damage to the developing bladder muscle and fibrosis.

A case of zinc chloride ingestion

Zinc chloride is a powerful corrosive agent. Reports of zinc chloride ingestion are uncommon, and there is little information about its toxicity and management. The authors report the clinical course of a 10-year-old girl who accidentally ingested an acid soldering flux solution (pH, 3.0; zinc chloride, 30% to < 60%). Systemic effects after the ingestion were unremarkable except for lethargy. Thus, chelation therapy was not considered. Severe gastric corrosion was caused by local caustic action. An antral stricture of the stomach approximately 3 weeks after the ingestion developed, and she underwent a modified Heineke-Mikulicz antropyloroplasty. Postoperatively, she made an uneventful recovery. On follow-up, although she was tolerating a normal diet, results of a barium meal showed her stomach to be totally aperistaltic. Results of a nuclear medicine study showed moderately delayed gastric emptying. Careful long-term follow-up is necessary, because there is potential risk for malignancy in the damaged stomach.

Renal dysplasia produced by obstructive uropathy in the fetal lamb

Aim: This study was undertaken to investigate the renal changes associated with obstruction of the urinary tract in the fetal lamb early in gestation (50 days). It was also undertaken to determine if urinary tract obstruction proximal or distal to the urinary bladder would result in varying renal morphology. Methods: Timed‐gestation ewes at 50‐days gestation were anaesthetised, and the lambs exposed. Males had their urethra and urachus ligated with a fine silastic tubing. Females had one ureter ligated with the same tubing. They were delivered at term and sacrificed. The kidneys were weighed, measured and processed for histological examination. Results: Three lambs (2 males and 1 female) survived. All 5 kidneys were small (2.2+/−0.4g, normal 17.3+/−1.3g), and had lost their normal architecture. Microscopically, these kidneys had few glomeruli, a relative abundance of stroma with apparent nodular collections of tubules surrounded in some instances by a cuff of fibrous stromal tissue. Conclusion: The morphologic features produced by urinary tract obstruction at 50‐days gestation in the lamb resembled those normally associated with human cystic renal dysplasia. The site of the obstruction had no effect on the development of subsequent renal pathology.

Fetal hydrops in experimental obstructive uropathy resolves after vesicostomy formation: is this cause and effect?

The association of obstructive uropathy and hydrops is rare but often fatal. Hydrops has been observed in our fetal lamb model with obstructive uropathy. We created a vesicoamniotic shunt 21xa0days after creating the obstruction to explore the effect of relieving the obstruction on the hydrops. Fetal lambs underwent urethral and urachal ligation at 60xa0days gestation. We created a vesicostomy (female) or urethrostomy (male) in 12xa0lambs to release the pressure 21xa0days after creating the obstruction. The fetuses were delivered at term (145xa0days), and the urinary tract was removed for histological examination. Six fetuses had severe hydrops at the time of the vesicostomy (groupxa0A), and six had no hydrops (groupxa0B). Only two lambs from groupxa0A survived (33%), and four lambs survived from groupxa0B (66%). Three lambs miscarried, and one was stillborn from groupxa0A. Two lambs from groupxa0B miscarried. In our fetal lamb model, hydrops appears to be associated with massive urinary ascites. We hypothesize that a connection exists between urinary ascites and hydrops. Vesicostomy, by bypassing the obstruction, may allow the lambs to recover from their hydrops. However, it is possible that by 21xa0days after creation of the obstruction, the damage created by the hydrops is irreversible.

Serum Creatine Kinase Levels Parallel the Clinical Course for Rhabdomyomatous Wilms Tumor

A right-sided renal mass in an 11-month-old girl was diagnosed by percutaneous needle biopsy as Wilms tumor, which on histologic examination was found to be predominantly rhabdomyomatous. As part of the examination, serum creatine kinase (CK) and CK-MB levels were measured and were significantly elevated at 994 U/L (reference range, 42-180 U/L) and 40 U/L (reference range, 0-3 U/L), respectively. Subsequently, an 8-month-old girl was admitted to the hospital with septicemia and was found to have an abdominal mass. A diagnosis of bilateral Wilms tumor was made following percutaneous biopsy of both kidneys; histologic examination confirmed that the tumor was predominantly rhabdomyomatous. Serum CK and CK-MB levels also were measured and were significantly elevated at 685 U/L and 84.4 U/L, respectively. In both cases, the serum CK and CK-MB levels reflected the clinical course; elevation in serum levels was associated with tumor recurrence, infarction, or chemotherapy-related necrosis. We conclude that these enzymes have clinical usefulness as markers for Wilms tumor showing rhabdomyomatous morphologic features.

Solitary intrahepatic biliary cyst: Diagnostic and therapeutic strategy

This paper describes a newborn infant in whom an intrahepatic biliary cyst was successfully demonstrated by antenatal ultrasound. Postnatally, percutaneous cyst aspiration and computed tomography enhanced with intravenous cholangiographic contrast proved extremely helpful in the selection of surgical procedure. The lesion was completely removed at 12 weeks of age without complications.

Childhood cholecystectomy in New Zealand: A multicenter national 10 year perspective

AIMnInternational studies show increasing incidence of cholelithiasis in childhood and an increasing caseload for the pediatric surgeon. We reviewed pediatric cholecystectomy in all four centers in New Zealand, examining changes in incidence and the demographics of the patient population.nnnMETHODnCoding data were used to retrieve case notes and extract demographic data, diagnosis, comorbidities, length of stay, and complications for patients less than 16years old undergoing cholecystectomy from January 1st, 2004-December 31st, 2013. Patients with congenital biliary malformations were excluded. Statistical analysis was performed using SPSS.nnnRESULTSn170 children required cholecystectomy. On average, 15 procedures were performed annually (IQR 8-24). There was a slight upward trend, with a gradient of 0.34 (P=0.63). Median age was 14 (range 2-15)years, male:female 2:3. While 72% of children were Caucasian, Māori were significantly overrepresented (20%). Numbers of Pacific Islander increased significantly over time (P=0.05), in line with population increases. Of 114 patients with complete dataset, 31% were overweight or obese. Complication rates were 8.8% overall, but 27% of complications occurred in Māori children. 40% of those suffering a complication were obese. Three complications were major, requiring return to theater. Mean length of stay was 5days.nnnCONCLUSIONSnNew Zealand has not seen the rapid increase in pediatric cholecystectomy experienced elsewhere in the OECD. However, the problem of adolescent biliary disease is prevalent. The average recipient of a cholecystectomy is 14years old, overweight, and Caucasian; though Māori have a high relative risk of both biliary disease and complicated postoperative course. The reasons for this remain unclear and require further study.

The prune belly syndrome in a female

Prune belly syndrome is an extremely rare congenital condition in both sexes, particularly in females, with less than 50 cases having been reported; by comparison, the condition is at most uncommon in males. There has been much debate over the pathogenesis of the syndrome, in particular between two main theories. The first implicates a failure of mesodermal cell migration as the primary cause, whereas the second pinpoints urinary distention as the initial event. We describe a case of prune belly syndrome in a female that backs up the second of these theories. The features and the alternative theories as to the aetiology of this syndrome are reviewed, along with an explanation for the marked sex difference.