Prenatal diagnosis of the megacystis-megaureter association

Cecal duplication cyst in an infant presenting as shock: A case report

BACKGROUND

Although intestinal obstruction is one of the most common surgical emergencies in an infant, it is difficult to diagnose neonatal enteric duplication cysts (EDC) preoperatively owing to their rarity as a cause of intestinal obstruction. We describe a case report of a neonatal EDC presenting intestinal obstruction and shock.

CASE SUMMARY

A 32-d-old male infant with a prenatal sonographic finding of bladder distension was admitted to our hospital for a severely distended abdomen, fever, and oliguria. The first diagnostic hypothesis was septic shock and intestinal obstruction. The patient's symptoms worsened; following an emergency surgical exploratory laparotomy and histopathological findings, the final diagnosis of cecal duplication cyst was confirmed. The patient's postoperative course was uneventful, and on the fifth postoperative day, oral feeding restarted. Twenty days later, the patient was discharged from the hospital.

CONCLUSION

Although EDC located in the cecum is exceptional, it should be considered when evaluating suspected intestinal obstruction and shock.

Antenatal Diagnosis of Renal Tract Anomalies: Has it Increased the Sum of Human Happiness?

When used as a screening procedure, ultrasound examination of the fetal urinary tract seldom leads to beneficial interventions. There is also a cost in terms of parental anxiety and unnecessary investigation and treatment. A formal screening programme would therefore be unjustified. However, screening of women for obstetric purposes will continue to reveal fetal abnormalities, and a strategy for dealing with these is needed. Antenatal treatments remain experimental; for most of the common conditions postnatal treatment has no urgency; and, in cases of minor abnormality detected by ultrasound, the best course may be to do nothing.

Fetal megacystis: A systematic review

Fetal megacystis is variably defined and understood. The literature on fetal megacystis was systematically reviewed, focusing on prenatal diagnosis, associations and outcomes. This yielded a total of 18 primary references and eight secondary references. Fetal megacystis has an estimated first-trimester prevalence of between 1:330 and 1:1670, with a male to female ratio of 8:1. In the first trimester, megacystis is most commonly defined as a longitudinal bladder dimension of ≥7 mm. Later in pregnancy, a sagittal dimension (in mm) greater than gestational age (in weeks) + 12 is often accepted. Megacystis can be associated with a thickened bladder wall, which has been objectively defined as >3 mm. Oligohydramnios is present in approximately half of all cases. The most common underlying diagnosis is posterior urethral valves (57%), followed by urethral atresia/stenosis (7%), prune belly syndrome (4%), megacystis-microcolon-intestinal-hypoperistalsis syndrome (MMIHS) (1%), and cloacal anomalies (0.7%). Karyotype anomalies are found in 15%, and include trisomy 18, trisomy 13 and trisomy 21. Ultrasound imaging alone is often insufficient to enable a definitive diagnosis, although it may indicate that a specific diagnosis is more likely. Overall, about 50% of reported fetuses with megacystis are terminated, but this proportion varies considerably between countries and over time. Prognostic stratification is evolving, with the most important factors being oligohydramnios, gestational age at diagnosis, degree of bladder enlargement, renal hyperechogenicity, karyotype, and sex.

CONCLUSIONS

This review demonstrated some consensus on the ultrasound criteria for defining fetal megacystis, and illustrated the spectrum of pathologies and their relative frequencies that can cause this condition. It also underlined important associated karyotype anomalies. To progress understanding of the natural history of enlarged fetal bladders, more accurate diagnostics are required, and risk stratification needs to be refined to facilitate prenatal counseling.

Imaging Evaluation of Fetal Megacystis: How Can Magnetic Resonance Imaging Help?

Evaluation of the kidneys, bladder, and amniotic fluid volume forms part of any standard obstetrical ultrasound. When a fetal genitourinary anomaly is suspected, a more detailed evaluation is necessary. This detailed imaging can be challenging in the setting of decreased or absent amniotic fluid or large maternal body habitus, and in complex malformations. In these situations, magnetic resonance imaging can help to better define the fetal anatomy and provide a more confident and specific prenatal diagnosis.

Efficacy of prenatal ultrasonography in diagnosing urogenital developmental anomalies in newborns

BACKGROUND

Showing a prevalence rate of 0.5-0.8%, urogenital malformations discovered in newborns is regarded relatively common. The aim of this study is to examine the efficacy of ultrasound diagnostics in detecting developmental disorders in the urogenital system.

METHODS

We have processed the prenatal sonographic and postnatal clinical details of 175 urogenital abnormalities in 140 newborns delivered with urogenital malformation according to EUROCAT recommendations over a 5-year period between 2006 and 2010. The patients were divided into three groups; Group 1: prenatal sonography and postnatal examinations yielded fully identical results. Group 2: postnatally detected urogenital changes were partially discovered in prenatal investigations. Group 3: prenatal sonography failed to detect the urogenital malformation identified in postnatal examinations. Urogenital changes representing part of certain multiple disorders associated with chromosomal aberration were investigated separately.

RESULTS

Prenatal sonographic diagnosis and postnatal results completely coincided in 45%, i.e. 63/140 of cases in newborns delivered with urogenital developmental disorders. In 34/140 cases (24%), discovery was partial, while in 43/140 patients (31%), no urogenital malformation was detected prenatally. No associated malformations were observed in 108 cases, in 57 of which (53%), the results of prenatal ultrasonography and postnatal examinations showed complete coincidence. Prenatally, urogenital changes were found in 11 patients (10%), whereas no urogenital disorders were diagnosed in 40 cases (37%) by investigations prior to birth. Urogenital disorders were found to represent part of multiple malformations in a total of 28 cases as follows: prenatal diagnosis of urogenital malformation and the findings of postnatal examinations completely coincided in three patients (11%), partial coincidence was found in 22 newborns (79%) and in another three patients (11%), the disorder was not detected prenatally. In four newborns, chromosomal aberration was associated with the urogenital disorder; 45,X karyotype was detected in two patients, trisomy 9 and trisomy 18 were found in one case each.

CONCLUSION

In approximately half of the cases, postnatally diagnosed abnormalities coincided with the prenatally discovered fetal urogenital developmental disorders. The results have confirmed that ultrasonography plays an important role in diagnosing urogenital malformations but it fails to detect all of the urogenital developmental abnormalities.

Gross anatomical study of bilateral megaureters associated with renal pelvis dilatation and a giant urinary bladder: an adult cadaver with a brief review of the literature

Although bilateral megaureters are not an infrequent occurrence in the urinary tract, bilateral megaureters associated with bilateral renal pelvis dilatation and a giant urinary bladder appear to be rare. In this paper, a cadaver case of an adult Japanese male with bilateral megaureters is described. In addition to describing and illustrating this case, the anatomy and etiology of these anomalous structures is discussed with a brief review of the literature.

Prenatal management of urogenital disorders

Antenatal sonography has markedly increased the detection of urogenital anomalies, including those conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder outlet obstruction but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida, can be corrected in utero, with improvements in hydrocephalus seen along with a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally now possible. As further techniques evolve to correct underlying disease processes, it becomes important to critically assess the therapies, particularly with long-term outcome data.

Prenatal management of urogenital disorders

Antenatal sonography has increased the detection of urogenital anomalies markedly, including conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder-outlet obstruction, but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida,can be corrected in utero, with improvements in hydrocephalus and a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally. As techniques evolve to correct underlying disease processes,it becomes important to assess the therapies critically, particularly with long-term outcome data.

Enlarged fetal bladder: Differential diagnosis and outcomes

The sonographic finding of an enlarged fetal bladder may simply be a transitory normal variant, but it may also be secondary to reflux or to obstructive, neurogenic, or myopathic causes. In this report, we describe the cases of 3 fetuses with an enlarged bladder, each of which had a different cause. The first fetus had posterior urethral valve obstruction, the second, a ruptured neurogenic bladder, and the third, megacystic-microcolon-intestinal hypoperistalsis syndrome. When sonographic examination reveals an enlarged fetal bladder, the ureter, kidneys, genitalia, and spine should be evaluated carefully. Although sonography is good at identifying urinary tract abnormalities, it often cannot provide the specific diagnosis or cause. We recommend frequent sonographic monitoring to evaluate such fetuses for persistence of or changes in bladder enlargement and for changes in the volume of amniotic fluid because these signs may be indicators of abnormalities of renal function and risk factors for a poor prognosis. Analysis of fetal electrolyte levels can also aid in determining the prognosis and whether the condition is amenable to therapeutic intervention.

Ultrasound assessment of detrusor muscle thickness in children with non-neuropathic bladder/sphincter dysfunction

OBJECTIVE

To measure detrusor muscle thickness in children with non-neuropathic bladder/sphincter dysfunction (NNBSD), and to evaluate the difference between children with various bladder dysfunctions and those with normal urodynamics.

MATERIALS AND METHODS

In 139 children the urodynamic study was performed, and the detrusor of the anterior bladder wall was measured using high-frequency ultrasonography (US). Children were categorized into five groups, according to urodynamic findings. Differences in detrusor thickness between groups were tested by one-way ANOVA with post hoc Scheffé test.

RESULTS

Forty-six children (33.1%) had normal urodynamics, and mean (+/-S.D.) detrusor thickness 1.3 +/- 0.5 mm (range 0.5-3.0). Fifty-two (37.4%) had urge syndrome, with detrusor thickness of 2 +/- 0.7 mm (1.0-3.6). Thirty-three (23.7%) had dysfunctional voiding, with detrusor thickness of 2.6 +/- 0.5 mm (1.5-3.6). Four (2.9%) had lazy bladder, with detrusor thickness of 0.9 +/- 0.1 mm (0.8-1.0), and four had anatomical infravesical obstruction, with detrusor thickness of 4.4 +/- 0.3 mm (4-4.6). The mean detrusor thickness in all children with NNBSD was 2.2 +/- 0.7 mm (range 0.8-3.6). Multiple comparisons showed significant difference between all groups, except between children with normal urodynamics and children with lazy bladder.

CONCLUSION

There is statistically significant difference in mean detrusor thickness between children with normal urodynamics and children with NNBSD. However, due to the overlap of measured values, it is not possible to determine the cut-off value that could be used to distinguish children with and without NNBSD.

Enlarged fetal bladders: aetiology, management and outcome

Ultrasound routinely identifies the fetal bladder from 10 weeks of gestation. Understanding the normal embryology of the fetal bladder forms the basis of understanding the mechanisms for pathology. Early onset megacystis <12 mm (maximum diameter) frequently regresses spontaneously however when associated with other structural abnormalities 40% are chromosomally abnormal. Survival in this group is rare and the underlying histopathology is of urethral fibrostenosis. Second and third trimester megacystic indicates a heterogenous group where a precise antenatal diagnosis may be impossible. A distended thick wall bladder associated with a dilated posterior urethra and oligohydramnios is pathonemonic of posterior urethral valves; without this combination of ultrasound signs the underlying pathology is less certain. Prediction of other aetiologies for the megacystis is less accurate but includes primary reflux, cloacal plate, urethral duplication and megacystic microcolon in the differential diagnosis. Robust published data is currently unavailable to define appropriate management for individual cases of megacystis. Therefore current best practice for antenatal management will be discussed.

Antenatal hydronephrosis. Fetal and neonatal management

As many as 1% of newborn infants have a prenatal diagnosis of hydronephrosis or significant renal pelvic dilation. Hydronephrosis often is caused by nonobstructive conditions. The likelihood of significant urologic pathology is directly related to the size of the fetal renal pelvis, and 90% with an anteroposterior diameter more than 2 cm need surgery or long-term urologic medical care. Following delivery, antibiotic prophylaxis should be administered and a renal sonogram and voiding cystourethrogram should be obtained. If there is grade 3 or 4 hydronephrosis, usually a diuretic renogram is recommended also. Pediatric urologic or pediatric nephrologic consultation usually is helpful in planing evaluation and treatment. Prenatal recognition of hydronephrosis allows neonatal diagnosis and treatment of urologic pathology, preventing complications of pyelonephritis and obstruction.

Ultrasound diagnosis of bladder outlet obstruction in rabbits

One of the primary characteristics of partial outlet obstruction secondary to BPH is an increase in bladder mass commonly referred to as bladder hypertrophy. This condition has been simulated in rabbits by the partial ligation of the catheterized urethra. Ultrasonography has been utilized in both adult and pediatric urology to visualize the bladder and diagnose specific bladder disorders. The aim of the present study is to determine if ultrasonography can visualize bladder wall hypertrophy induced by obstruction. Partial outlet obstructions were created in NZW rabbits using standard methodologies, and then 5 to 7 days later, sonography was performed. The films were read by both the principal investigator and blinded investigators instructed to determine bladder wall thickness and from this predict the bladder weight. Then results were correlated with cystometrograms (CMGs) and whole bladder weights. Both the principal investigator and the blinded investigators were consistently able to distinguish obstructed from control bladders based solely on sonographic depictions of relative bladder wall thickness. In addition, the investigators were able to distinguish between low (control), medium, and high bladder weights based on sonography. The accuracy of predicting the bladder weights increased when cystosonograms were correlated with CMG studies. Thus, the degree of bladder hypertrophy can be accurately estimated by the combination of cmg and ultrasonography.