Prenatal sonographic monitoring of idiopathic megacystis.

This case report is of a female fetus diagnosed with severe idiopathic megacystis at 21 weeks of pregnancy. Sonographic monitoring demonstrated normal amniotic fluid volume and renal structures, absence of hydronephrosis, ureteral dilation, and associated abnormalities. Conservative management was chosen with postnatal confirmation of diagnosis. The neonate presented seizures, and subsequent magnetic resonance imaging demonstrated transverse sinus thrombosis with adjacent ischemic damage. At present, the infant is 2 years old, and she is thriving normally and maintains urinary continence with spontaneous voidings.

Fetal genitourinary imaging.

The fetal urinary tract is routinely evaluated sonographically beginning in the first trimester with documentation of fetal bladder visualization. Fetal MR might be indicated to further clarify abnormalities found sonographically. The primary imaging modality for evaluation of the fetal kidney is US, which plays an important role in the detection of collecting system dilatation and parenchymal diseases that influence counseling and postnatal care. A commonly seen birth defect affecting the fetal kidney is pyelectasis. The significance of this finding has been extensively evaluated by a number of fetal imaging centers and will be presented in this review. Further topics of interest within the fetal genitourinary system include fetal renal parenchymal disorders and fetal bladder abnormalities. Characteristic imaging features, as well as developmental pathology and differential considerations, are discussed here.

Allantoic cysts and posterior urethral valves: a case report.

Allantoic cysts are a somewhat rare entity. They are identifiable on antenatal ultrasound examination but are not easily distinguishable from pseudocysts, which are often associated with a poor prognosis. Their etiology remains obscure and obstructive uropathies have been proposed to be one of the underlying mechanisms. We report on a case in which both allantoic cysts and a patent urachus were detected antenatally and turned out to be associated with posterior urethral valves (PUV). The cysts were first seen in the early second trimester, with a full fetal bladder and patent urachus. They disappeared by the 29(th) week. During the subsequent sonographic examinations, the bladder was emptying regularly. The kidneys remained normal throughout the pregnancy. It is hypothesized that the increased pressure within the urinary tract kept the urachus patent, led to the formation of allantoic cysts and, later, to their perforation; this allowed the fetus to empty his bladder and kept him from the usual complications of PUV. This case emphasizes the importance of detection and characterization of umbilical cord cysts on antenatal ultasound examination and suggests that obstructive uropathies should be included in the differential diagnosis of umbilical cord cyst communicating with the fetal bladder.

Fetal cardiovascular effects of lower urinary tract obstruction with giant bladder.

OBJECTIVE: Lower urinary tract obstruction (LUTO) with massive bladder distension impacts on a variety of developing organ systems with consequent morbidity and mortality. The impact of LUTO on the fetal cardiovascular system has not previously been investigated. We hypothesize that a giant, distended bladder within the pelvis may cause vascular compression with observable consequences. METHODS: Fetal echocardiography was performed in 42 fetuses with LUTO and compared with 35 normal controls matched for gestational age. Parameters investigated included cardiothoracic ratio, presence or absence of ventricular hypertrophy and pericardial effusion. Doppler echocardiographic examination of mitral and tricuspid valve inflow and the ductus venosus was performed. To assess arterial vascular impedance, pulsatility indices (PIs) were calculated for segments of the descending aorta and right and left iliac arteries (RIA and LIA). RESULTS: In the LUTO group an increased cardiothoracic ratio was seen in nine (21%), ventricular hypertrophy in 12 (29%) and small pericardial effusion in 15 (36%). Filling characteristics of the right ventricle in the LUTO group demonstrated greater dependency upon atrial contraction, and ductus venosus flow demonstrated higher downstream impedance to filling, than in controls, suggesting altered compliance. The LUTO group also had lower distal descending aorta PI (1.53 ± 0.38 vs. 1.76 ± 0.44, P = 0.04), lower RIA-PI (1.31 ± 0.29 vs. 1.76 ± 0.44, P < 0.001) and lower LIA-PI (1.41 ± 0.44 vs. 1.73 ± 0.31, P < 0.01) than controls, suggesting vascular compression and increased impedance to flow. CONCLUSIONS: LUTO with giant urinary bladder compresses the iliac arteries, which may lead to increased afterload. Further study is warranted to examine the impact of fetal treatment such as bladder drainage on these cardiovascular parameters.

Fetal urinary bladder rupture and urinary ascites secondary to posterior urethral valves. A case report.

Megacystis is a typical prenatal sonographic finding in cases of lower urinary tract obstruction. Urinary bladder perforation represents a rare complication in this condition. We report on a boy with in utero bladder perforation and urinary ascites secondary to posterior urethral valves. The pre- and postnatal therapy is described and the current literature is reviewed.

In utero urinary bladder rupture: a case report.

We report a case of foetal urinary bladder rupture due to posterior urethral valves. A megacystis was diagnosed in a male foetus during routine second trimester ultrasound examination. The diagnosis of bladder rupture was made as, one week later, the bladder became undetectable with the appearance of ascites. During the follow-up, no oligohydramnios developed and intercurrent ascites resolved spontaneously. There are three described mechanisms releasing bladder hyperpressure: bladder diverticles, unilateral vesicoureteral reflux and bladder rupture. In this case, another mechanism might be involved: a patent urachus. The urethral valves were resected and no other surgical treatment was needed. The renal function remained normal. No long-term vesical follow-up of this pathology is available in the literature.

Uncommon ureteric ectopias: embryological implications.

We herein report two rare ureteric ectopias, one in the uterus, the second in the rectum. These kinds of ectopias are not easily explained with regard to the classic embryological theories of the too-cranial or too-caudal origin of the ureteric bud on the mesonephric duct. We thus set out new explanations consistent with embryological studies on the narrow contact between the developing paramesonephric and mesonephric ducts, and on the so-called cloacal septation.

Prenatal resolution of megacystis possibly caused by spontaneous rupture of posterior urethral valves.

We report herein a case of resolution of severe megacystis, possibly caused by spontaneous rupture of posterior urethral valves during follow-up on a prenatal ultrasound. A 32-year-old woman presented at gestational week 15 for evaluation of fetal bladder enlargement. Prenatal ultrasonography revealed megacystis and posterior urethral dilatation. The longitudinal diameter of the bladder was 25 mm. Megacystis spontaneously resolved at gestational week 16. No association with urinary ascites was observed, and amniotic fluid volume remained normal throughout gestation. A boy was delivered vaginally at week 37. Apgar scores were 8 at 1 minute and 9 at 5 minutes. The neonate voided smoothly. Ultrasonography revealed a thickened bladder wall and normal kidneys and upper urinary tracts. Voiding cystourethrography showed dilatation of the posterior urethra but confirmed normal bladder capacity with smooth voiding and no vesicoureteral reflux. On day 57, remnant valves were incised. Postoperatively, filling cystometry showed a compliant bladder with no involuntary phasic contraction. At 7 months follow-up, the infant was asymptomatic, and ultrasonography showed some improvement of bladder wall thickness. Resolution of megacystis in utero appears to have resulted from spontaneous rupture of the posterior urethral valves. To the best of our knowledge, no similar cases have been previously reported.

Antenatal detection of grossly distended bladder owing to absence of the urethra in a fetus with trisomy 18.

An ultrasonic examination revealed a grossly distended fetal abdomen. Amniocentesis at 19 weeks' gestation showed raised amniotic fluid alphafetoprotein, a second band of specific acetylcholinesterase, and a fetal karyotype 47,XY,+18. The pregnancy was terminated and the necropsy examination showed absence of the urethra, grossly distended bladder, hydroureters, and congenital heart anomalies.

[The intrauterine rupture of the fetal bladder as a complication of low urinary tract obstruction]. / Die intrauterine Blasenruptur als Komplikation infravesikaler Harnentleerungsstörungen beim Feten.

Lower urinary tract obstruction in fetuses causes megacystis, megaureter and hydronephrosis. The spontaneous rupture of the fetal bladder represents a rare complication in cases of total bladder outlet obstruction. We report about two different cases, present pre- and postnatal therapeutic regimes and discuss the possibility of spontaneous healing of a ruptured fetal bladder before delivery.

[Malformations of the fetal urinary tract of surgical significance. Diagnosis on the basis of pre- and post-natal imagings]. / Malformazioni dell'apparato urinario fetale di interesse chirurgico. Diagnostica per immagini pre- e post-natale.

Out of the 29 cases of fetal urinary tract anomalies detected by sonography, the authors report on the 17 cases with potentially correctable malformations. A critical analysis of the diagnostic contribution offered by the radiologic and sonographic studies is presented. The role of ultrasound examination in the choice of a suitable investigation strategy is emphasized, underlining the importance of an accurate approach to avoid diagnostic errors and unuseful procedures. The indications for fetal and neonatal antegrade pyelography are discussed.

Megacystis microcolon intestinal hypoperistalsis syndrome with bilateral duplicated systems.

A 29-year-old multigravida woman presented for her second prenatal ultrasound evaluation at 30 weeks of gestation. The study showed a female fetus, bilateral duplicated systems with severe hydronephrosis in the upper pole moieties and a massively distended bladder. Initial interpretation suggested ectopic/obstructing bilateral ureteroceles. To evaluate these findings further, a prenatal magnetic resonance imaging scan was obtained, documenting the absence of ureteroceles. The presumptive diagnosis of megacystis microcolon intestinal hypoperistalsis syndrome was made. After birth, contrast enema confirmed the presence of microcolon. This appears to be the first reported case of megacystis microcolon intestinal hypoperistalsis syndrome with bilateral duplex systems evaluated with prenatal magnetic resonance imaging.