Posterior urethral valves presented at birth despite normal prenatal ultrasound scans

Abdominal distension and lower extremity edema

Posterior urethral valves are a congenital malformation in males that results in the obstruction of urinary outflow from the proximal urethra. Presentation depends on severity of disease, with patients presenting antenatally with oligohydramnios and hydronephrosis, to postnatally with delayed or poor voiding, urinary tract infections, or renal anomalies on ultrasound. Our case illustrates an 11-day-old male who presented to the emergency department with poor feeding, vomiting, significant abdominal distension, and pitting edema of the lower extremities. The patient was found to have hypoglycemia, hyponatremia, hyperkalemia, and acute renal failure. Point of care ultrasound showed severe bilateral hydronephrosis with a significantly distended bladder that was compressing the inferior vena cava. Early recognition of the obstruction via ultrasound led to rapid decompression of the bladder using catheterization and immediate involvement of urology, nephrology, and neonatology consults in the pediatric emergency department.

Pyeloplasty for pelviureteric obstruction junction obstruction

Pelviureteric junction obstruction (PUJO) is a common clinical presentation. Patients require investigation with biochemistry and imaging in the form of computed tomography and diuretic renography. The gold-standard pyeloplasty treatment is minimally invasive pyeloplasty. Here we discuss a typical presentation of PUJO and discuss key questions in the investigation, management and follow-up of this condition, including a review of the treatment options.

Level of evidence: 3a

Risk factors associated with chronic kidney disease in patients with posterior urethral valves without prenatal hydronephrosis

PURPOSE

Postnatal diagnosis of posterior urethral valves continues despite the prevalence of prenatal ultrasound. We identified risk factors associated with chronic kidney disease in these children.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of boys with posterior urethral valves with clinical presentations other than prenatal hydronephrosis. We recorded presenting symptoms, age at presentation, and preoperative hydronephrosis and/or vesicoureteral reflux. Chronic kidney disease was defined as previous renal transplantation, dialysis dependence or glomerular filtration rate less than 60 ml per minute/1.73 m(2) at last followup. We used univariate survival analysis with the log rank test of equality for categorical variables and Cox proportional hazard regression for continuous variables to identify risk factors associated with progression to chronic kidney disease.

RESULTS

We identified 141 boys with posterior urethral valves with a postnatal presentation. Median age at presentation was 46 months (range 0.3 to 174). Febrile urinary tract infection in 28% of patients and voiding complaints in 50% were the most common presentations. A total of 12 patients (9%) progressed to chronic kidney disease up to 23 years after initial presentation. Preoperative bilateral hydronephrosis, increased hydronephrosis severity and bilateral vesicoureteral reflux were associated with progression to chronic kidney disease.

CONCLUSIONS

Approximately 10% of cases with postnatal presentation of posterior urethral valves progress to chronic kidney disease, sometimes decades after the initial presentations. Although all patients with posterior urethral valves should be counseled on the potential loss of renal function, children with risk factors warrant close followup into adulthood.

Hydronephrosis in infants and children: natural history and risk factors for persistence in children followed by a medical service

Background:

Infants with neonatal hydronephrosis and a normal voiding cystourethrogram (VCUG) are presumed to have ureteropelvic junction obstruction (UPJO). There is little current information about the natural history of children with hydronephrosis or clinical factors that predict resolution of the radiological abnormality.

Objective:

To determine the time course until spontaneous resolution of neonatal hydronephrosis and define risk factors for persistence of the abnormality.

Methods:

This retrospective single center review examined infants and children <5 years of age with hydronephrosis who were followed for at least 12 months.

Results:

136 children were identified (96 male:40 female). The mean age at diagnosis of hydronephrosis was 3.3 ± 9.7 months and 76% of the patients were diagnosed at birth. The hydronephrosis was unilateral in 98 (72%) of cases, and hydronephrosis was at least moderate in severity in 22% of affected kidneys. At last follow-up at 30 ± 10 months, the abnormality had resolved in 77 out of 115 (67%) available patients, 30 (26%) had been referred to urology, and 12 (10%) had persistent hydronephrosis. Severity of hydronephrosis was the only clinical feature that predicted persistence of the abnormality (P < 0.001). There was an association between detection at birth and lack of resolution of hydronephrosis.

Conclusions:

Children with hydronephrosis and presumed UPJO and normal kidney parenchyma can be followed for at least 2 years to allow for spontaneous resolution before referral to urology. Serial sonography can be performed at 6 month intervals in uncomplicated cases. More severe hydronephrosis and presence of the lesion at birth may predict infants and children requiring closer observation and referral for possible surgical correction of the hydronephrosis.

Sonography of fetal micturition

OBJECTIVE

To describe the sonographic visualization of fetal micturition and its role in the diagnosis of posterior urethral valves and hypospadias.

METHODS

This was a prospective study of 25 male fetuses (21 with bilateral pyelectasis, one whose bladder was being studied because of ureterocele and three with hypospadias), and five female fetuses (with bilateral pyelectasis). A midline sagittal scan of the fetal pelvis, perineum and external genitalia was obtained and observed continuously during fetal micturition.

RESULTS

In 19 of the 21 male fetuses and the five female fetuses with bilateral pyelectasis micturition was normal, with visualization of urinary bladder contraction, slight fluid distention of the urethra and a urinary stream from the external urethral meatus. In three male fetuses, two with bilateral pyelectasis and the one with ureterocele, the posterior urethra was normal at rest and it ballooned out during micturition, diagnostic of posterior urethral valves. In the three male fetuses with hypospadias the ventral jet of the urinary stream was visualized.

CONCLUSION

Fetal micturition can be visualized on sonography. It may be of value in the diagnosis of posterior urethral valves and hypospadias.