Follow-up of children after fetal treatment for obstructive uropathy

Kidney function and transplants in prune belly syndrome: a scoping review

BACKGROUND

Children with prune belly syndrome (PBS) are at higher risk of developing kidney dysfunction and requiring kidney replacement therapy (KRT). While studies have described surgical and survival outcomes in these populations, there has yet to be a focused synthesis of evidence regarding kidney outcomes in this population. Here, the focus of this scoping review was to highlight knowledge gaps and report standards on kidney outcomes in PBS of all ages.

METHODS

Following scoping review methodology, EMBASE, MEDLINE, and Scopus were searched for peer-reviewed literature that describe kidney outcomes in PBS. All studies with a broad set of kidney outcomes (such as kidney function measures, chronic kidney disease (CKD), KRT and associated outcomes) were included. Findings were summarized and qualitatively synthesized.

RESULTS

Of the 436 unique records identified, 25 were included for synthesis. A total of 17 studies (441 patients) reported on kidney insufficiency outcomes, with an estimated prevalence of CKD ranging from 8 to 66%. A total of 15 studies (314 patients) described KRT, primary kidney transplant, and outcomes. Of these, the age for KRT ranged from 4 to 21 years, and graft survival ranged from 22 to 87% by last follow-up (range 1.3-27 years).

CONCLUSIONS

There is significant variability in studies reporting kidney outcomes in PBS which limits meaningful synthesis. There is a need for future studies with comprehensive reporting of confounders and drivers for kidney insufficiency in PBS.

Bladder Cancer in a Long-term Survivor of the Prune Belly Syndrome

Prune belly syndrome (PBS) is a rare but morbid complexity of congenital anomalies that consists of abdominal wall defect, bilateral cryptorchidism, and urinary tract dilation. With the recent advances in perinatal care, the life expectancy of patients with PBS has improved. Although renal and sexual outcomes are frequently discussed in the literature, little is known about urinary tract malignancies in adulthood. Herein, we present a case of advanced bladder cancer in a 38-year-old man with PBS. To the best of our knowledge, a malignant tumor arising in a nondefunctionalized or nonaugmented bladder in patients with PBS has not been reported previously.

Pulmonary complications of abdominal wall defects

The abdominal wall is an integral component of the chest wall. Defects in the ventral abdominal wall alter respiratory mechanics and can impair diaphragm function. Congenital abdominal wall defects also are associated with abnormalities in lung growth and development that lead to pulmonary hypoplasia, pulmonary hypertension, and alterations in thoracic cage formation. Although infants with ventral abdominal wall defects can experience life-threatening pulmonary complications, older children typically experience a more benign respiratory course. Studies of lung and chest wall function in older children and adolescents with congenital abdominal wall defects are few; such investigations could provide strategies for improved respiratory performance, avoidance of respiratory morbidity, and enhanced exercise ability for these children.

New and/or improved aspects of fetal surgery

Open fetal surgery through a wide hysterotomy is no longer a real option for prenatal intervention, but a minimally invasive approach has emerged as treatment for a small number of indications. Endoscopic ablation of placental vessels is the preferred treatment for severe twin-to-twin transfusion syndrome and it may be the only chance to salvage the most severe forms of congenital diaphragmatic hernia. Several other indications are currently under review and may become justified in the future, provided that diagnostic accuracy and patient selection become more accurate. Before invasive fetal intervention becomes widely accepted, however, we need to better define outcome. It is no longer acceptable to express results in terms of survival at birth. Survival at discharge and long-term morbidity must be considered as well.

Fetal lower urinary tract obstruction

Fetal lower urinary tract obstruction affects 2.2 per 10,000 births. It is a consequence of a range of pathological processes, most commonly posterior urethral valves (64%) or urethral atresia (39%). It is a condition of high mortality and morbidity associated with progressive renal dysfunction and oligohydramnios, and hence fetal pulmonary hypoplasia. Accurate detection is possible via ultrasound, but the underlying pathology is often unknown. In future, magnetic resonance imaging (MRI) may be increasingly used alongside ultrasound in the diagnosis and assessment of fetuses with lower urinary tract obstruction. Fetal urine analysis may provide improvements in prenatal determination of renal prognosis, but the optimum criteria to be used remain unclear. It is now possible to decompress the obstruction in utero via percutaneous vesico-amniotic shunting or cystoscopic techniques. In appropriately selected fetuses intervention may improve perinatal survival, but long-term renal morbidity amongst survivors remains problematic.

Urological emergency in neonates with congenital hydronephrosis

OBJECTIVE

It is well described that unilateral pelviureteric junction obstruction (PUJO) is a benign condition, because the dilatation resolves spontaneously and the function does not decrease in most of the kidneys. However, there is exceptional PUJO that requires emergent treatment in neonatal periods. The aim of this article is to report the urological emergency and management in neonates with PUJO.

MATERIALS AND METHODS

Nine children (seven boys and two girls) with PUJO who underwent neonatal emergent treatment during the last 13 years were reviewed. Renal function was evaluated according to decay curve of serum creatinine (SCr) levels corresponding to gestational age (GA) at delivery. Physical examination, ultrasonographic monitoring, and chest and abdominal plain radiographs were repeated in each neonate.

RESULTS

Eight patients were detected prenatally. In five patients, multicystic dysplastic kidney (MCDK) was demonstrated on the contralateral side. Three patients underwent percutaneous puncture of fetal hydronephrosis. Decrease of amniotic fluid was evident in three fetuses. Indications for emergent treatment included mass effect from hydronephrosis in three patients, renal dysfunction in five, and severe urinary tract infection in one. During neonatal periods, a percutaneous nephrostomy tube was placed in seven, and open nephrostomy in one with anorectal malformation. Repeated punctures of the dilated renal pelvis were done in one patient. Renal function after pyeloplasty was stable in eight patients, while it was moderately decreased in one who was associated with oligohydramnios in utero.

CONCLUSION

Indications for emergent treatment in neonates with PUJO included mass effect from giant hydronephrosis, renal dysfunction and severe urinary tract infection. At birth, respiratory and circulatory conditions must first be stabilized. In neonates with hydronephrosis of the solitary kidney or severe bilateral PUJO, serial SCr should be monitored to evaluate renal function. Decrease of amniotic fluid suggested renal functional compromise that would not recover after urological management.

Prenatal ultrasound guided percutaneous shunts for obstructive uropathy and thoracic disease

The authors reviewed the status of closed ultrasound-guided fetal therapy using a pigtail shunt to create vesicoamniotic or thoracoamniotic decompression of the fluid-filled space. This review includes published and textbook reports of in utero therapy for bladder obstruction, pleural effusion, and macrocystic adenomatoid malformation from 1985 through 2002. For fetuses affected by lower urinary tract obstruction, the key component is identifying those fetuses that have retained renal function and are most likely to benefit from in utero shunting. This good prognosis group has been shown to have improved survival rate and a lower incidence of renal failure. Complications of fetal loss are estimated at 5% owing to the shunt procedure, and the risk of shunt displacement varies from 30% to 50%. Hydrops secondary to primary PE has been shown to be associated with low fetal and neonatal survival at 21% to 23%. Treatment by thoracoamniotic shunting increases survival rate to 75%. The fetus with a macrocystic CCAM and secondary hydrops should be considered a candidate for thoracoamniotic shunt to decrease CCAM volume, reverse hydrops, and improve survival rate. Thoracoamniotic shunt and thoracocentesis pregnancy loss risks for pleural effusion (PE) and macrocystic adenomatoid malformation of the lung (CCAM) are 5% and 0.5% to 1.0%, respectively.

Survival in second trimester oligohydramnios secondary to bilateral pelviureteral junction obstruction

The extent and onset of obstruction in hydronephrosis determine the varying degrees of renal impairment. Bilateral hydronephrosis, especially in combination with oligohydramnios, is considered a negative predictor for pregnancy outcome. We describe a case of bilateral pelviureteral junction obstruction causing severe oligohydramnios between 25 and 29 weeks of gestation. The prenatal and postnatal findings and treatment are demonstrated. In the presence of bilateral renal impairment and oligohydramnios, our patient had an unfavorable prognosis. The respiratory and renal function, however, were better than expected. We show how urinary tract reconstruction and neonatal intensive therapy can result in an acceptable outcome.

Urethral atresia: long-term outcome in 6 children who survived the neonatal period

PURPOSE

Urethral atresia is incompatible with life unless an alternative communication between the bladder and amniotic sac exists. Although antenatal intervention may improve perinatal mortality, clinical consequences remain. We outline the outcome after treatment of 6 patients born with urethral atresia.

MATERIALS AND METHODS

We reviewed the charts of 6 patients with urethral atresia treated at the Children's Hospital of Michigan between 1982 and 1999. Patient age ranged from 3 to 17 years (mean 9). All patients were males (46 XY) and presented at birth or in early infancy.

RESULTS

Oligohydramnios was demonstrated in 4 of the 6 patients (67%). A vesico-amniotic shunt had been placed in 2 patients (at more than 30 weeks of gestation and in 1 at 17 weeks of gestation). The remaining 3 patients presented at birth with either a vesicocutaneous fistula or patent urachus. Bilateral or unilateral hydronephrosis was identified in 4 patients while 2 had severe renal dysplasia. Cystography identified moderate to high grade vesicoureteral reflux in all patients, and 5 (83%) had the prune belly syndrome. Mean serum creatinine at age 1 year was 1.3 mg/dl (range 0.5 to 2.1). Renal failure occurred in 5 patients (83%) before age 10 years and 4 of them have received a renal transplant. An average of 7.8 (range 9 to 14) urological procedures were performed on each patient. Progressive urethral dilation was not successful in the majority of our cases and ultimately 67% required some form of supravesical diversion.

CONCLUSIONS

Our study demonstrates that urethral atresia is not necessarily fatal. Prenatal decompression allows survival and in some cases may even lead to normal bladder and renal function. A complicated clinical course requiring extensive reconstruction is to be expected.

Urethral atresia: long-term outcome in 6 children who survived the neonatal period

PURPOSE

Urethral atresia is incompatible with life unless an alternative communication between the bladder and amniotic sac exists. Although antenatal intervention may improve perinatal mortality, clinical consequences remain. We outline the outcome after treatment of 6 patients born with urethral atresia.

MATERIALS AND METHODS

We reviewed the charts of 6 patients with urethral atresia treated at the Children's Hospital of Michigan between 1982 and 1999. Patient age ranged from 3 to 17 years (mean 9). All patients were males (46 XY) and presented at birth or in early infancy.

RESULTS

Oligohydramnios was demonstrated in 4 of the 6 patients (67%). A vesico-amniotic shunt had been placed in 2 patients (at more than 30 weeks of gestation and in 1 at 17 weeks of gestation). The remaining 3 patients presented at birth with either a vesicocutaneous fistula or patent urachus. Bilateral or unilateral hydronephrosis was identified in 4 patients while 2 had severe renal dysplasia. Cystography identified moderate to high grade vesicoureteral reflux in all patients, and 5 (83%) had the prune belly syndrome. Mean serum creatinine at age 1 year was 1.3 mg/dl (range 0.5 to 2.1). Renal failure occurred in 5 patients (83%) before age 10 years and 4 of them have received a renal transplant. An average of 7.8 (range 9 to 14) urological procedures were performed on each patient. Progressive urethral dilation was not successful in the majority of our cases and ultimately 67% required some form of supravesical diversion.

CONCLUSIONS

Our study demonstrates that urethral atresia is not necessarily fatal. Prenatal decompression allows survival and in some cases may even lead to normal bladder and renal function. A complicated clinical course requiring extensive reconstruction is to be expected.

Prenatal hydronephrosis

Prenatal hydronephrosis is diagnosed with an incidence of 1:100 to 1:500 maternal-fetal ultrasonographic studies. Although ultrasonography accurately describes dilation of the renal collecting system, it cannot define mechanical obstruction, a functional characteristic. The purpose of prenatal screening has changed from simple detection of hydronephrosis to selection for specific diagnosis-based management. The natural history of prenatal hydronephrosis is difficult to determine, and therefore physicians who take care of the fetus and infant are challenged with the following question: when does dilation of the renal collecting system indicate that serious pathology (ongoing renal deterioration) exists? The diagnosis of prenatal hydronephrosis, indications for and timing of prenatal intervention, and recommendations for treating children with a history of prenatal hydronephrosis are included in this review.

Posterior urethral valves: pre- and postnatal management

Posterior urethral valves are a common problem encountered by pediatric urologists. The diagnosis is most frequently suggested by antenatal screening ultrasound. A variety of pre- and postnatal parameters have been identified to aid in predicting ultimate renal outcome. These prognostic tools are invaluable to the clinician for counseling parents and for choosing appropriate management. Several approaches to the treatment of patients with posterior urethral valves exist, and the ideal strategy is debatable. As technology evolves, more options for early intervention become available. Whether early detection and antenatal intervention improve patient outcome remains to be proven.

Histology of the fetal prune belly syndrome with reference to the efficacy of prenatal decompression

BACKGROUND

Deficient abdominal musculature, complex abnormalities of urinary tracts and bilateral abdominal cryptorchidism represent the basic characteristics of prune belly syndrome (PBS). Although prenatal diagnosis of PBS is rarely made, because of the wide variety of ultrasonographic images, reported cases have gradually increased. Once a fetus suspected of having PBS is found, it is sometimes difficult for the pediatric urologists to decide how to treat them. The histology of the kidney and urinary tracts in fetuses with PBS was reviewed in order to give suggestions on the management of prenatal cases.

METHODS

Autopsy records of nine fetuses (5 males, 2 females and 2 undetermined) with characteristically distended and deficient abdominal wall were reviewed. Gestational age (GA) at detection ranged from 12 to 25 weeks and at delivery from 13 to 32 weeks.

RESULTS

Renal histology in two fetuses showed earlier than normal disappearance of cortical nephrogenic zone replaced by cortical cysts and dysplastic structures. The nephrogenic zone was retained in five fetuses which were younger than GA 20 weeks. While the number of glomeruli along the medullary ray was normal for the age in three fetuses younger than GA 20 weeks, it was decreased in all others. Bladder histology was variable showing both increased musculature and defective or dysplastic muscles. There was a tendency for connective tissues in the bladder wall to increase in proportion to GA, The ureter revealed scarcity of muscle bundles among dense connective tissue. The urethra was atretic in eight fetuses.

CONCLUSION

The clinical implication from the renal histology is that decompression of the urinary tract should be done before GA 20 weeks. However, the early fetal treatment appears to have no effect on the urodynamics in this disorder with deficient musculature.

Successful in utero endoscopic ablation of posterior urethral valves: a new dimension in fetal urology

Fetal lower urinary tract obstructive uropathy, when associated with oligohydramnios, is usually associated with a poor outcome. We present a case of successful in utero endoscopic ablation of posterior urethral valves in which the infant survived the neonatal period without evidence of renal dysplasia. The role, indications, and potential benefits of this novel technique are discussed.

Clinical results of fetal obstructive uropathy treated by vesicoamniotic shunting

OBJECTIVES

To report the clinical results of 5 fetuses after a vesicoamniotic shunting procedure (VASP).

METHODS

Between 1995 and 1998, 5 patients (two with prune belly syndrome, one with a cloacal anomaly, one with urethral stenosis, and one with a sacrococcygeal teratoma) underwent VASP using a double-basket catheter. We used the following selection criteria: a fetus without chromosomal defects, with oligohydramnios, and with a predicted good renal function from sequential or single fetal urinalysis (sodium concentration, chloride concentration, and osmolarity at less than 100 mEq/L, less than 90 mEq/L, and less than 210 mOsm, respectively).

RESULTS

The mean gestational age was 20.8 +/- 6.9 weeks at diagnosis, 24.2 +/- 6.0 weeks at VASP, and 30.6 +/- 6.2 weeks at delivery. In our study, 2 of 5 patients survived. One of the patients with prune belly syndrome was 18 months old at last follow-up, with hydrocephalus and a creatinine level of 0.2 mg/dL. The patient with the cloacal anomaly was 4 years old at last follow-up and had signs of clonic convulsion. However, psychomotor development was delayed in both. Of the 3 patients who died, 2 died after birth, and the autopsy determined death was due to pulmonary insufficiency. The patient with urethral stenosis died in utero.

CONCLUSIONS

Although the principal purpose of VASP is to prevent pulmonary hypoplasia and dysfunctional kidneys, VASP was not always effective, as the outcomes were poor in most of our patients. A greater standardization of patient selection and a large cohort study in the future should be considered to assess VASP.