"Lying-Down" Adrenal Sign: There Are Exceptions to the Rule Among Fetuses and Neonates

Prenatal diagnosis of ectopic kidney: Evaluation of characteristics, additional anomalies and urinary complications

OBJECTIVE

To assess the characteristics, additional structural anomalies and postnatal urinary outcome of the cases diagnosed with fetal ectopic kidneys in the prenatal period.

STUDY DESIGN

Cases having fetal ectopic kidneys, detected from a total of 14,617 pregnant women examined by routine detailed (Group 1) or indicated (Group 2) obstetric ultrasonography (USG) in a tertiary perinatology unit were analyzed. The prevalence of the cases, time of the diagnosis, sidedness of the affected kidney, anatomical location, origins of blood supply, additional urinary or extraurinary anomalies, and urinary complications during the postnatal follow-up period were investigated.

RESULTS

We have detected 33 fetuses with ectopic kidneys in our cohort. The prevalence of fetal ectopic kidney was 0.22 %, with a median (min.-max.) diagnosis time of 21.3 (17.6-34) weeks. In the group in whom indicated USG was performed, the time of diagnosis was later compared to routine detailed USG (p = 0.04) group. There was no difference in terms of gender [male, (n = 14), female (n = 19), p = 0.38] and the sidedness of the ectopic kidneys (p = 0.38). The location of ectopic kidneys was most frequent in the iliac fossa (n = 20, 60.6 %) and in the lateral pelvic areas (n = 13, 39.3 %). The blood supply origin of ectopic kidneys was the common iliac artery in 22 (66.6 %), whereas the aorta in 11 cases (33.3 %). There was an additional urinary anomaly in 8 cases (24 %), an extraurinary structural anomaly, most commonly cardiac, and/or a soft marker for aneuploidy were presented in 16 cases (48 %). The most common urinary complication in the postpartum period was vesicoureteral reflux (n = 5).

CONCLUSION

Ectopic kidney in the prenatal period is a rare structural anomaly that can equally affect both genders and both kidneys. Prenatal diagnosis is important for the diagnosis of additional anomalies and follow-up of postnatal complications.

Prenatal diagnosis of intrathoracic kidney and adrenal gland in left-sided congenital diaphragmatic hernia

A 29-year-old primigravida at 31 weeks of gestation was referred for intrathoracic kidney (ITK). Ultrasound revealed left kidney intrathoracic placement with an anteriorly positioned ectopic adrenal gland. Magnetic resonance imaging confirmed diaphragmatic interruption and colon herniation. A female neonate, delivered at 37 weeks, underwent successful thoracoscopic repair for a left Bochdalek hernia. Despite compression of the left lung, notably optimistic lung-to-head ratio (LHR) values were observed, correlating with favorable outcomes. This case underscores the rare occurrence of ITK, its association with Bochdalek hernia, and the importance of comprehensive prenatal evaluations.

Troubleshooting Tips for Diagnosing Complex Fetal Genitourinary Malformations

Fetal genitourinary anomalies can present a diagnostic challenge for the radiologist. The absence of a normally located kidney may represent agenesis or be secondary to a fusion or migration abnormality. A dilated renal pelvis should prompt evaluation for a specific cause, including ureteropelvic junction obstruction, reflux, or an obstructed duplicated system. Cystic parenchymal changes are characteristic of a multicystic dysplastic kidney but may also be seen in obstructive cystic dysplasia. There are numerous causes of megacystis including chromosomal (trisomy 18 syndrome), obstruction (posterior urethral valves, urethral atresia), or muscular dysfunction (prune belly syndrome, megacystis microcolon intestinal hypoperistalsis syndrome). Important mimics of a large bladder include hydrocolpos and urogenital sinus or cloacal malformation. Complications of genitourinary malformations are common and include oligohydramnios, urinary ascites, and urinoma. Making an accurate diagnosis often requires additional US views beyond those obtained in the standard fetal survey and occasionally performing fetal MRI. The appropriate use of orthogonal T2-weighted sequences, in conjunction with diffusion-weighted images for evaluation of the kidneys and gradient-recalled-echo sequences for evaluation of T1-hyperintense meconium in the colon, can play an integral role in diagnosis. Accurate diagnosis of fetal genitourinary malformations is vital to direct patient counseling and pregnancy management as outcomes are highly variable. Some conditions can be surgically corrected quite simply, some require multiple complex procedures, and some are lethal. The authors offer troubleshooting tips to narrow the differential diagnosis for four observations: unilateral absent kidney, dilated renal pelvis, cystic renal parenchyma, and megacystis and its mimics. ©RSNA, 2023 Test Your Knowledge questions are available in the Online Learning Center.

A new sonographic marker in the diagnosis of prenatal bilateral renal agenesis, segmental anterior deviation of the aorta

Objectives

Bilateral renal agenesis is a rare congenital anomaly that is associated with high neonatal mortality. Bilateral renal agenesis is most often present with anhydramniosis in the mid-trimester.

Case presentation

We report a case of bilateral renal agenesis diagnosed prenatally. We presented the ultrasound and pathology images of this fetus with a new sonographic sign, segmental anterior deviation in the abdominal aorta.

Conclusions

To our knowledge, this is the first reported case of a fetus with a segmental aortic anterior deviation.

Fetal interventions for congenital renal anomalies

Congenital abnormalities of the kidney and urinary tract (CAKUT) represent 20% of prenatally diagnosed congenital abnormalities. Although the majority of these abnormalities do not require intervention either pre or postnatally, there is a subset of patients whose disease is so severe that it may warrant intervention prior to delivery to prevent morbidity and mortality. These cases consist of patients with moderate lower urinary tract obstruction (LUTO) in which vesicocentesis, shunting or cystoscopy are options and patients with early pregnancy renal anhydramnios (EPRA) in whom amnioinfusion therapy may be an option. The main causes of EPRA are congenital bilateral renal agenesis (CoBRA), cystic kidney disease (CKD) and severe LUTO. Untreated, EPRA is universally fatal secondary to anhydramnios induced pulmonary hypoplasia. The evidence regarding therapy for LUTO is limited and the stopped early PLUTO (Percutaneous Shunting in Lower Urinary Tract Obstruction) trial was unable to provide definitive answers about patient selection. Evidence for EPRA therapy is also scant. Serial amnioinfusions have shown promise in cases of EPRA due to CoBRA or renal failure and this treatment modality forms the basis of the ongoing NIH funded RAFT (Renal Anhydramnios Fetal Therapy) trial. At present, there is consensus that treatment for EPRA should only occur in the setting of a clinical trial.

Etiology and management of early pregnancy renal anhydramnios: Is there a place for serial amnioinfusions?

Early pregnancy renal anhydramios (EPRA) comprises congenital renal disease that results in fetal anhydramnios by 22 weeks of gestation. It occurs in over 1 in 2000 pregnancies and affects 1500 families in the US annually. EPRA was historically considered universally fatal due to associated pulmonary hypoplasia and neonatal respiratory failure. There are several etiologies of fetal renal failure that result in EPRA including bilateral renal agenesis, cystic kidney disease, and lower urinary tract obstruction. Appropriate sonographic evaluation is required to arrive at the appropriate urogenital diagnosis and to identify additional anomalies that allude to a specific genetic diagnosis. Genetic evaluation variably includes karyotype, microarray, targeted gene testing, panels, or whole exome sequencing depending on presentation. Patients receiving a fetal diagnosis of EPRA should be offered management options of pregnancy termination or perinatal palliative care, with the option of serial amnioinfusion therapy offered on a research basis. Preliminary data from case reports demonstrate an association between serial amnioinfusion therapy and short-term postnatal survival of EPRA, with excellent respiratory function in the neonatal period. A multicenter trial, the renal anhydramnios fetal therapy (RAFT) trial, is underway. We sought to review the initial diagnosis ultrasound findings, genetic etiologies, and current management options for EPRA.