Anorectal Malformations: Finding the Pathway out of the Labyrinth

MR Imaging of the Fetal Gastrointestinal Anomalies

Fetal MR imaging has been shown to be a useful tool for the diagnosis of fetal gastro-intestinal pathologies. To recognize the various pathologies, it is, however, essential to know the normal MR imaging appearance of the fetal bowel at various gestational ages. By providing additional information to ultrasound in case of a fetal gastrointestinal anomaly, MR imaging helps to improve planning for the delivery, postnatal management, and improves parental counseling.

T2-based magnetic resonance genitography in children with complex anorectal malformations: experience at a tertiary pediatric hospital in Latin America

In children with anorectal malformations (ARMs), it is essential to have a diagnostic imaging method that helps with the evaluation of the internal anatomy. In patients with a persistent cloaca, an ARM variant, in which the measurement of the urethral channel and common channel determines surgical management, there are multiple options for imaging. Magnetic resonance imaging (MRI) is an excellent method for this purpose, from which accurate measurements of channel length can be obtained. Additionally, the use of volumetric/isotropic sequences allows multiplanar reformatting. We present our experience with pelvic MRI and intracavitary non-paramagnetic contrast (MR genitography). This method uses volumetric T2-weighted images and the instillation of saline solution as a contrast agent to distinguish the common channel, length of the urethra, anatomy of the vagina, and presence and location of the rectal fistula. We believe this technique to be particularly useful for those working in settings with limited MRI resources.

Multimodality imaging of diseases of the vagina

Pathologies of the vagina are important causes of symptoms related to the genital tract in women. They can be missed on transabdominal ultrasonography (USG), which is the baseline modality used for evaluation of gynaecological complaints. Transperineal USG and MRI are the imaging modalities of choice for evaluation of the vagina. Diseases of the vagina can be grouped depending upon the age group in which they occur. In children and young adults, congenital anomalies like longitudinal or transverse vaginal septum, imperforate hymen, vaginal aplasia or atresia, and rectovaginal fistula can be seen. Malignant tumours can rarely occur in children, rhabdomyosarcoma being the most common one. Common diseases affecting adults include benign lesions like epidermoid, Gartner duct, and Bartholin cysts, and urogenital fistulas involving the vagina. Endometriosis and other benign tumours of vagina including leiomyoma, fibroepithelial polyp, and angiomyxoma are occasionally seen. Malignant tumours can be primary, the most common one being squamous cell carcinoma, or secondary, due to direct extension from cancers involving the adjacent organs. Characteristic morphological changes occur in the vagina after radiotherapy, which can be identified on imaging. Knowledge about the imaging appearances of these diseases is crucial in guiding appropriate management.

The comparison of magnetic resonance and fluoroscopic imaging options in the preoperative assessment of boys with anorectal malformations and a colostomy

BACKGROUND

In recent decades, magnetic resonance imaging (MRI) has gained prominence as a standard diagnostic method for preoperative assessment in patients with anorectal malformations and a colostomy, with the potential to replace the classic fluoroscopic distal pressure colostogram (FDPC). Three MRI techniques are available: MRI-distal pressure colostogram with gadolinium (MRI-DPCG) or saline (MRI-DPCS) instillation into the colostomy and native MRI without colostomy instillation.

OBJECTIVE

To evaluate and compare the diagnostic accuracy of MRI (native MRI, MRI-DPCG and MRI-DPCS) in the preoperative workup of boys with an anorectal malformation and a colostomy and to compare it to FDPC.

MATERIALS AND METHODS

Sixty-two boys with preoperative MRI using one of the three approaches and 43 with FDPC met the inclusion criteria for this retrospective study. The presence and localization of rectal fistulas according to the Krickenbeck classification were evaluated and compared with intraoperative findings.

RESULTS

The accuracy of fistula detection for MRI in general (regardless of the technique), MRI-DPCS, MRI-DPCG, native MRI and FDPC was 95% (59/62, P<0.001), 100% (12/12, P=0.03), 100% (30/30, P<0.001), 85% (17/20, P=0.41) and 72% (31/43, P=0.82), respectively. The accuracy of describing fistula type in patients with a correctly detected fistula using these methods was 96% (45/47, P<0.001), 100% (9/9, P<0.001), 100% (23/23, P<0.001), 87% (13/15, P<0.001) and 67% (13/21, P=0.002), respectively.

CONCLUSION

MRI is a reliable method for detecting and classifying fistulas in boys with an anorectal malformation and a colostomy and can be considered the modality of first choice for preoperative workup.

Absent Thumb and Radius in a Neonate With Tracheo-Esophageal Fistula and Ventricular Septal Defect: VACTERL Association

A complex of anomalies involving the vertebral column and spinal canal (V), anal atresia(A), congenital lesions of the heart (C), defects involving the trachea esophageal complex (TE), renal system, and urinary tract (R), and limb lesions (L) is known as VACTERL complex. VACTERL is an umbrella term for patients with abnormalities involving three or more of the systems mentioned above. It can be potentially life-threatening and should be promptly recognized and managed. Thorough investigations are required to prevent long-term sequelae and to improve morbidity. We present a case of a neonate born to a mother with twin gestation at 38 weeks of gestation with antenatally diagnosed severe polyhydramnios and a single umbilical artery and vein. This manuscript discusses the imaging findings of the congenital abnormalities involving the cardiac and skeletal system with tracheoesophageal fistula in our patient.

Prenatal magnetic resonance imaging of complex female genitourinary system abnormalities, what the fetal medicine specialist needs to know

Complex female genitourinary system anomalies include a wide spectrum of uncommon pathologies, caused from the abnormal separation of the urorectal septum and the urogenital sinus in early embryonic life. The resulting fusion of the distal urinary, genital and intestinal tracts increases the risk of death in utero and alters the normal organ functionality and the quality of life in survivors. An accurate prenatal identification of these pathologies depends mainly on prior suspicion at ultrasound screening, but also requires a solid knowledge of embryology and familiarity with the different patterns of malformation. Prenatal MRI provides an excellent anatomic evaluation of the fetal anatomy that may improve the diagnosis in complex cases with inconclusive echographic findings. The additional information can help both families and medical teams to better evaluate the severity of the pathology and the postnatal prognosis and therefore to better orientate the management during pregnancy, at delivery and after birth. This review article describes the embryological basis and the clinical findings of the most relevant pathologies included in the spectrum. It also describes the imaging signs on prenatal MRI studies in a series of confirmed cases and proposes a diagnostic algorithm based on imaging findings for guiding prenatal diagnosis.

Low muscle volume of the anal sphincter complex: A novel prognostic factor in children with anorectal malformations?

BACKGROUND/PURPOSE

The anal sphincter complex (ASC) plays a key role in continence and is often dysfunctional in infants born with anorectal malformations (ARM). The ASC is well depicted by magnetic resonance (MR) imaging but volumetric reference data are lacking in infants. Thus, we tested the feasibility of MR based ASC volumetry, collected reference data, and compared them with cases of favorableprognosis and unfavorable prognosis (as defined by the type of ARM).

METHODS

We determined ASC volume on T2 weighted MR images of seventy six infants (ARM n = 33; controls n = 43) by manual segmentation. Inter operator agreement was assessed by intraclass correlation coefficient. Linear regression was used to establish weight dependent reference data. Observed to expected ASC volumes of patients with unfavorable and favorable prognosis were compared (unpaired t test).

RESULTS

ASC volumetry was feasible in all cases. Patients with ARM had low 'observed to expected' ASC volume ( 18.1%; p = 0.006). 'Observed to expected' ASC volume differed significantly between patients with favorableand unfavorable prognosis (p < 0.001).

CONCLUSION

We confirmed the feasibility of MRI based ASC volumetry and provided initial reference data for infants. Although ASC volumes were lowest in infants with ARM of unfavorable prognosis for fecal continence, the value of ASC volume as prognostic parameter remains to be determined.

Internal fat prolapse from ischiorectal fossa masquerading as currarino syndrome

Pelvic magnetic resonance imaging (MRI) is the latest addition to already existing tools for evaluation of anorectal malformation (ARM). It provides detailed information about pelvic floor musculature as well as position of rectal pouch. However, lack of knowledge about normal pelvic floor anatomy can lead to misinterpretation of pelvic MRI which can create confusion and change in approach for surgery. A 14-month-old male child with diagnosis of ARM was evaluated with pelvic MRI. There was finding of abnormal protrusion of fat through the ischiorectal fossa which was misinterpreted as Currarino syndrome which created confusion immediately before posterior sagittal anorectoplasty. Pelvic MRI is highly informative while evaluating a case of ARM. However, a detailed knowledge of pelvic floor anatomy is mandatory to avoid wrong interpretation and misdiagnosis.

Gastrointestinal Emergency in Neonates and Infants: A Pictorial Essay

Gastrointestinal (GI) emergencies in neonates and infants encompass from the beginning to the end of the GI tract. Both congenital and acquired conditions can cause various GI emergencies in neonates and infants. Given the overlapping or nonspecific clinical findings of many different neonatal and infantile GI emergencies and the unique characteristics of this age group, appropriate imaging is key to accurate and timely diagnosis while avoiding unnecessary radiation hazard and medical costs. In this paper, we discuss the radiological findings of essential neonatal and infantile GI emergencies, including esophageal atresia and tracheoesophageal fistula, hypertrophic pyloric stenosis, duodenal atresia, malrotation, midgut volvulus for upper GI emergencies, and jejunoileal atresia, meconium ileus, meconium plug syndrome, meconium peritonitis, Hirschsprung disease, anorectal malformation, necrotizing enterocolitis, and intussusception for lower GI emergencies.

Imaging of anorectal malformations: where are we now? Abdominal imaging task force of the European Society of Paediatric Radiology

Anorectal and cloacal malformations are a broad mix of congenital abnormalities related to the distal rectum and anus. Confusion exists between all the forms in this large and heterogeneous group. The spectrum includes everything from anal stenosis, ventral anus, anal atresia (with and without fistula) and the full spectrum of cloacal malformations. Imaging in these conditions is done through the whole armamentarium of radiologic modalities, with very different imaging strategies seen across the centres where these conditions are managed. In 2017, the European Society of Paediatric Radiology (ESPR) abdominal imaging task force issued recommendations on the imaging algorithm and standards for imaging anorectal malformations. This was followed by further letters and clarifications together with an active multispecialty session on the different imaging modalities for anorectal malformations at the 2018 ESPR meeting in Berlin. Through this paper, the abdominal task force updates its guidelines and recommended imaging algorithm for anorectal malformations.

Evaluation and management of rectovaginal fistula in anorectal malformation: an observational study

PURPOSE

The rectovaginal fistula (RVF) is a type of female ARM in which the rectum terminates in the vagina. Due to its rarity, there are limited reports on its presentation, management, and follow-up. This paper deals with the clinical presentation, management, and outcome of RVF.

METHODS

It was a retrospective cohort study of 10 years. The patients were evaluated for age, clinical presentation, associated anomalies, any prior surgical interventions performed elsewhere, and complications. After workup, the patients underwent three stages of surgery.

RESULTS

Fifty-six patients of RVF were managed. The median age was 13.48 months. The associated anomalies were present in 37 (66%) patients. Posterosagittal and anterosagittal anorectoplasty (PSARP and ASARP) were performed in 29 and 6 patients, respectively. Abdominoperineal pull-through (APPT) was performed in 16 patients of congenital pouch colon. The complications of the first stage included stomal stenosis (4) and stomal prolapse (3). Constipation was present in 39 patients 2 years after the third surgery.

CONCLUSIONS

RVF is a distinct entity, which needs careful clinical examination. With proper planning for diagnosis and treatment, it can be managed at specialized centers. Care may be needed for the associated anomalies. The follow-up is an integral part of its management.

Case report: a de-novo 7p12.3 microduplication detected in an infant with perineal hamartoma and imperforate anus

Background

Anorectal malformations (ARM) represent a wide spectrum of defects. Caudal and genitourinary malformations can associate with anorectal malformations. Genetic factors may play role in the development of anorectal malformations. Perineal masses like sacrococcygeal teratoma, rectal prolapse, or duplication cysts were reported before, but their association with perineal hamartoma and anal atresia is extremely rare.

Case presentation

Here, we report an 11-month-old female infant. She had 551 kb duplication at 7p12.3 with perineal hamartoma and anal atresia consisting a cystic lesion with a diameter of 4 mm at the filum terminale (L2 vertebra) on lumbar magnetic resonance imaging (MRI) in neonatal period. She presented with hypotonia. She had anorectal anomaly and external perineal mass bulging from left major labium extending across anal region with imperforate anus. There was 1 × 1 cm polyp-like protrusion on it. She was operated in neonatal period. Genetic laboratory investigations showed karyotype 46, XX. The microduplication of the chromosome 7p12.3 was detected by microarray analysis. There were not any significant homozygous or heterozygous variants determined  by whole-exome sequencing.

Conclusions

To the best of our knowledge, this is the first report of a patient with a microduplication of the chromosome 7p12.3, and second case with perineal hamartoma and imperforate anus. Clinicians should pay attention to microdeletions and microduplications while giving genetic counseling to patients with urogenital and anorectal abnormalities.

Pelvic Floor Muscles Contribution in Surgical Outcome of Children with High-type Anorectal Malformations

As a consequence of high-type anorectal malformations (ARMs) pathogenesis, the pelvic floor muscles remain severely underdeveloped or hypoplastic, the rectal pouch is located at the level or above the puborectalis sling, and the bowel terminates outside the sphincter muscle complex support. For children with high-type ARMs the ultimate objective of therapy is mainly to grow up having bowel continence function that is compatible with a good quality of life, and the final prognosis depends significantly on the grade of development of pelvic floor muscles and the successful entering of the anorectum fully within the support of the external anal sphincter due to intraoperative conservation of the puborectalis sling. Pelvic magnetic resonance imaging (MRI) has recently become the preferred imaging study for prediction of functional outcomes, since it can define the anatomy and evaluate the development of the sphincteric muscles before and after surgical correction. Based on recent literature and our clinical experience, we will discuss the relevance of pelvic floor muscles MRI to the clinical outcome of children with high type ARMs.

Prenatal ultrasound findings of covered bladder exstrophy and persistent cloaca

Unlike classic exstrophy, covered bladder exstrophy is a rare variant characterized by a cycling bladder and intact abdominal wall. We present a case of covered bladder exstrophy diagnosed prenatally and associated persistent cloaca (PC) noted only after delivery. This case report demonstrates that prenatal diagnosis of covered bladder exstrophy is possible and PC can present without any abdominal cysts, bowel, or renal findings. Covered bladder exstrophy should be considered in the differential of cystic protrusion of the bladder to the abdominal wall.

Accuracy of pre-operative fistula diagnostics in anorectal malformations

Background

Surgical safety during posterior sagittal anorectal plasty (PSARP) for anorectal malformations (ARM) depends on accurate pre-operative fistula localization. This study aimed to evaluate accuracy of pre-operative fistula diagnostics.

Methods

Ethical approval was obtained. Diagnostic accuracy of pre-PSARP symptoms (stool in urine, urine in passive ostomy, urinary tract infection) and examination modalities (voiding cystourethrogram (VCUG), high-pressure colostogram, cystoscopy and ostomy endoscopy) were compared to final intra-operative ARM-type classification in all male neonates born with ARM without a perineal fistula treated at a tertiary pediatric surgery center during 2001–2020.

Results

The 38 included neonates underwent reconstruction surgery through PSARP with diverted ostomy. Thirty-one (82%) had a recto-urinary tract fistula and seven (18%) no fistula. Ostomy endoscopy yielded the highest diagnostic accuracy for fistula presence (22 correctly classified/24 examined cases; 92%), and pre-operative symptoms the lowest (21/38; 55%). For pre-operative fistula level determination, cystoscopy yielded the highest diagnostic accuracy (14/20; 70%), followed by colostogram (23/35; 66%), and VCUG (21/36; 58%). No modality proved to be statistically superior to any other.

Conclusions

Ostomy endoscopy has the highest diagnostic accuracy for fistula presence, and cystoscopy and high-pressure colostogram for fistula level determination. Correct pre-operative ARM-typing reached a maximum of 60–70%.

Visualization of the fetal anus by prenatal ultrasound for the diagnosis of anorectal malformations: is it feasible?

PURPOSE

The goal of this study was to determine the feasibility of identifying the anal dimple (AD) on routine prenatal ultrasound. Using the presence, absence, appearance, and location of the anal dimple as an indirect sign for possible underlying anorectal malformations (ARM), we hypothesize that evaluation of the anal dimple as part of the fetal anatomic survey may increase the sensitivity in detecting less severe ARMs.

METHODS

In a prospective longitudinal observational study, pregnant women who underwent prenatal ultrasound (US) at the Colorado Fetal Care Center between January 2019 and 2020 were enrolled. The variables recorded included gestational age, singleton versus multiple pregnancy, gender of the fetus, visualization of the AD, and reason for non-visualization of the AD.

RESULTS

A total of 900 ultrasounds were performed, evaluating 1044 fetuses, in 372 different pregnant women. Gestational ages ranged from 16 to 38 weeks. The AD was visualized in 612 fetuses (58.6%) and not seen in 432 (41.4%). The two most common reasons for non-visualization were extremes in gestational age (n = 155; 36%) and fetal position (n = 152; 35.3%). The optimal gestational age range for AD visualization was 28-33 weeks + 6 days, with 78.1% visualization rate.

CONCLUSION

Visualization of the anal dimple by ultrasound is feasible and may aid in the detection of less severe ARMs, ultimately impacting pregnancy management and family counseling. The optimal timing for anal dimple visualization is late second and third trimester.

Role of Transperineal Ultrasound (TPUS) in Children with Ambiguous Genitalia

Objectives  Accurate delineation of anatomy in children with ambiguous genitalia early in life is important. This commonly involves conventional fluoroscopic genitogram (traumatic to the child) and magnetic resonance imaging (MRI) examination (involves sedation). In this study, our objectives were twofold: (1) to describe the findings on transperineal ultrasound (TPUS) in normal children and (2) to describe the findings on TPUS in children with ambiguous genitalia and correlate them with conventional genitogram. Materials and Methods  TPUS was prospectively performed in 10 children without genital ambiguity (5 girls and 5 boys). Subsequently, 15 consecutive children having disorders of sex differentiation (DSDs) with genital ambiguity underwent TPUS. The presence or absence of müllerian structures was documented. Of these patients, 14 also underwent conventional genitogram as a part of routine evaluation. The gold standard was established either by comparison with surgical findings (in patients who underwent surgery) or by comparison with a combination of findings on genitogram and transabdominal ultrasound in patients who did not undergo surgery. Results  In all normal children, lower urogenital tracts could be clearly delineated on TPUS. Out of the 15 children with ambiguous genitalia, TPUS could establish the presence/absence of müllerian structures in 14. This was concordant with findings on conventional genitogram/surgery. In one patient, müllerian structure was missed on TPUS but demonstrated on genitogram. In two children, TPUS showed the müllerian structure, which was not seen on genitogram. When both the controls and the cases were combined, TPUS had an accuracy of 95% and specificity of 100% in the detection of müllerian structures. Conclusion  TPUS is feasible and accurate in demonstration of lower urogenital tract anatomy in children with DSDs having ambiguous genitalia. It can be performed without sedation, and is suitable for use as a screening modality in children with ambiguous genitalia.

The perineal midsagittal view in male fetuses - pivotal for assessing genitourinary disorders

A wide range of genitourinary pathologies can be diagnosed in utero, from a simple vesicoureteral reflux to a more complex disorder of sexual differentiation. The prognosis and neonatal management of these conditions differ significantly. Evaluation of the fetal perineal anatomy is paramount to making the right diagnosis. The aim of this pictorial essay is to show sonographers how to acquire a perineal midsagittal view in a male fetus, and to demonstrate how this specific view allows assessment of the urethra and penis, to differentiate various genitourinary pathologies.

Successful Surgical Correction of Congenital Colonic Duplication and Anogenital Cleft in a Cat

A 17 wk old sexually intact female domestic shorthair kitten presented for an anogenital cleft and enlarged colon. The cat had experienced bacterial cystitis and constipation since weaning. Contrast referral images revealed an enlarged colon with a patent anus. Clinical examination revealed an anogenital cleft with a common anovulvar orifice. The rectum was patent upon digital rectal palpation, and fecal contamination of the vulva was present. Abdominal radiographs revealed two distinct colons, both filled with a moderate amount of formed fecal material. Contrast-enhanced computed tomography revealed segmental duplication of the descending colon with a dominant right colon and a smaller accessary left colon. The two structures conjoined at the transverse colon proximally and at the pubic brim distally. A common anogenital orifice with anovulvar communication was also noted. The anogenital cleft malformation was successfully repaired surgically. A celiotomy was performed to remove the smaller accessory colon. An ovariectomy and partial hysterectomy were also performed. The patient recovered uneventfully and showed no gross evidence of recurrent cystitis or urinary or fecal incontinence postoperatively. This is believed to be the first report of a congenital anogenital cleft and complete communicating colonic duplication in a cat.

Imaging of anorectal malformations in utero

PURPOSE

To document the imaging findings suggestive of anorectal malformation (ARMs) on prenatal US and MRI.

METHODS

Retrospective evaluation of the screening US and prenatal MRI exams of the rectum and ano-perineal region in normal fetuses and in patients with ARMs.

RESULTS

Examples showing the normal rectal and anoperineal anatomy on prenatal US and MRI exams and the imaging findings observed in different types of confirmed ARMS.

CONCLUSIONS

Prenatal diagnosis of ARMs requires both a systematic evaluation of the fetal pelvis and perineum and an appropriate knowledge of its suggestive imaging findings.

Prenatal imaging of anorectal malformations - 10-year experience at a tertiary center in Switzerland

BACKGROUND

Anorectal malformation is a spectrum of congenital defects of the distal bowel, mostly diagnosed at birth.

OBJECTIVE

To describe the prenatal imaging findings of anorectal malformations, explore the causes of the low rates of prenatal diagnosis, compare the accuracy of prenatal ultrasound (US) and magnetic resonnance imaging [MRI] and evaluate the relevance of information obtained at MRI.

MATERIALS AND METHODS

Children treated for anorectal malformation at our hospital and with available prenatal studies were retrospectively identified and included in the study. We reviewed prenatal imaging exams, listed findings suggestive of the diagnosis, and compared results with the final classification.

RESULTS

Fourteen fetuses and neonates - eight with intermediate-high type anorectal malformation and six with cloacae - fulfilled the inclusion criteria. All had associated congenital anomalies. Prenatal exams included 13 US and 8 MRI exams, with 7 children having both exams. Suggestive findings for anorectal malformation were detected in 50% of the cases prenatally and in 85% upon review. They were prospectively detected in 31% and 50% of the cases at US and MRI and retrospectively in 62% and 100% at US and MRI, respectively. MRI was superior to US because it improved the diagnosis, especially in cloacae, and provided relevant additional information that changed management in two cases.

CONCLUSION

The most important signs suggesting anorectal malformation are an absent target sign and anomalous distal bowel wall and rectal fluid. Complementary prenatal MRI improves the diagnosis of anorectal malformation.

Fetal megacystis: a lot more than LUTO

OBJECTIVE

Fetal megacystis presents a challenge in terms of counseling and management because of its varied etiology and evolution. The aim of this study was to present a comprehensive overview of the underlying etiologies and structural anomalies associated with fetal megacystis.

METHODS

This was a retrospective multicenter study of cases referred to the fetal medicine unit of one of the eight academic hospitals in The Netherlands with a diagnosis of fetal megacystis. For each case, data on and measurements of fetal urinary tract and associated structural anomalies were collected. All available postmortem examinations and postnatal investigations were reviewed in order to establish the final diagnosis. In the first trimester, fetal megacystis was defined as longitudinal bladder diameter (LBD) ≥ 7 mm, and in the second and third trimesters as an enlarged bladder failing to empty during an extended ultrasound examination lasting at least 40 min.

RESULTS

Of the 541 pregnancies with fetal megacystis, it was isolated (or solely accompanied by other signs of lower urinary tract obstruction (LUTO)) in 360 (67%) cases and associated with other abnormal ultrasound findings in 181 (33%) cases. The most common associated ultrasound anomaly was an increased nuchal translucency thickness (22%), followed by single umbilical artery (10%) and cardiac defect (10%). A final diagnosis was established in 418 cases, including 222 (53%) cases with isolated LUTO and 60 (14%) infants with normal micturition or minor isolated urological anomalies. In the remaining 136 (33%) cases, concomitant developmental or chromosomal abnormality or genetic syndrome was diagnosed. Overall, 40 chromosomal abnormalities were diagnosed, including trisomy 18 (n = 24), trisomy 21 (n = 5), Turner syndrome (n = 5), trisomy 13 (n = 3) and 22q11 deletion (n = 3). Thirty-two cases presented with anorectal malformations involving the anus, rectum and urogenital tract. In cases with confirmed urethral and anal atresia, megacystis occurred early in pregnancy and the bladder appeared severely distended (the LBD (in mm) was equal to or greater than twice the gestational age (in weeks)). Fetal macrosomia was detected in six cases and an overgrowth syndrome was detected in four cases, comprising two infants with Beckwith-Wiedemann syndrome and two with Sotos syndrome. Megacystis-microcolon-intestinal hypoperistalsis syndrome was diagnosed in five (1%) cases and prenatally suspected only in one case.

CONCLUSIONS

Although the main cause of fetal megacystis is LUTO, an enlarged fetal bladder can also be present as a concomitant finding of miscellaneous genetic syndromes, developmental disturbances and chromosomal abnormalities. We provide an overview of the structural anomalies and congenital disorders associated with fetal megacystis and propose a practical guide for the differential diagnosis of genetic syndromes and chromosomal and developmental abnormalities in pregnancies presenting with fetal megacystis, focusing on the morphological examination of the fetus. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Complete Urogenital and Anorectal Duplication in a Dog

A 10-week-old sexually intact female golden retriever was evaluated for two functional anal openings and a bipartite vulva. Examination revealed haired skin between two separate anatomically smaller anal openings. On rectal palpation, a soft tissue septum (5 cm) with a mucosal surface between the two anal openings was palpated. In addition, circumferential rectal musculature was not appreciated on the ventral aspect. Urogenital evaluation revealed duplication of the vestibule and vagina with a complete centrally located septum extending dorsoventrally. Computed tomography (CT) of the abdomen and pelvis, vaginocystourethrogram, and colonogram were performed. Complete bifurcation of the urinary bladder with duplication of the urethra, cervix, and vaginal canal was noted. Approximately 2 cm from the rectum, there was a similar bifurcation that converged the colon into two rectal portions and separate anal openings. The owner was counseled on the severity of congenital malformations and a high likelihood of aging-related developmental complications in the future. The owner elected humane euthanasia and a necropsy was performed to confirm the malformations.

Anatomical alterations following the 'PSARP' procedure: Correlating MRI findings with continence scores

PURPOSE

To identify anatomical aberrations following PSARP procedure by using MRI, while correlating MRI findings to clinical outcome.

PATIENTS AND METHODS

Between January 2014 and December 2017, we conducted our study on male patients with rectourethral fistula who underwent PSARP. Postoperative pelvic MRI studies were performed and correlated to their clinical continence scores (Rintala, and Krickenbeck classification).

RESULTS

The study included 31 patients. Fourteen patients were retrieved from the hospital records and accepted to participate in the study; while the remaining 17 were collected from the fecal incontinence clinic. Their age ranged from 40 to 156 months (mean 83) We divided patients in the study into two groups according to their Rintala continence scores: (Group A) 15 patients with low scores (10 or less); and (Group B) 16 patients with higher scores (more than 10). We detected wider pelvic hiatus (hiatus/PC ratio) and more obtuse anorectal angle in group A than B.

CONCLUSION

Several anatomical alterations can be detected by MRI following the PSARP procedure that include abnormalities in the striated muscle sphincter (attenuation/deficiency), deviated neorectum, and presence of excessive perirectal fat. A widened pelvic hiatus and/or obtuse anorectal angle may correlate with poor fecal continence in these patients.

LEVEL OF EVIDENCE

This is a case control study (level III evidence).

Ultrasound imaging of the anorectal malformation during the neonatal period: a comprehensive review

Anorectal malformation (ARM) is classified as low, intermediate, or high; accurate diagnosis of the type during the early neonatal period is important to determine the appropriate initial surgical approach. This review assesses the role of ultrasound examination in the classification of ARM during the neonatal period, with a focus on landmarks on the sonogram, the approach used for sonography, and the optimal examination timing. The following three factors on the sonogram are used for the classification: location of the fistula, the distance between the distal rectal pouch and the anal dimple (perineum) (P-P distance), and the relationship between the puborectalis muscle and the distal rectal pouch. Three approaches can be used to evaluate ARM by ultrasonography, namely, suprapubic, perineal, and infracoccygeal approaches. Each approach has its own advantages and disadvantages. Optimal timing of the ultrasound examination is also important with respect to each factor to classify ARM. We have described the pitfalls of ultrasound in diagnosis of cases, namely ARM with Down syndrome (which tends to be without fistula), ARM with low birth weight, ARM with unusual location of fistula, ARM with opened fistula (where the P-P distance is unreliable), and cloacal malformation (variation of the high-type ARM).

Multimodality Imaging Review of Anorectal and Perirectal Diseases with Clinical, Histologic, Endoscopic, and Operative Correlation, Part II: Infectious, Inflammatory, Congenital, and Vascular Conditions

A broad spectrum of pathology affects the rectum, anus, and perineum, and multiple imaging modalities are complementary to physical examination for assessment and treatment planning. In this pictorial essay, correlative imaging, endoscopic, pathologic, and operative images are presented for a range of rectal, perirectal, and perineal disease processes, including infectious/inflammatory, traumatic, congenital/developmental, vascular, and miscellaneous conditions. Key anatomic and surgical concepts are discussed, including radiological information pertinent for surgical planning, and current operative approaches of these anatomic spaces to assist radiologists in comprehensive reporting for gastroenterologists and surgeons.

Magnetic resonance imaging evaluation after anorectal pull-through surgery for anorectal malformations: a comprehensive review

Anorectal malformations (ARM) include congenital anomalies of the distal anus and rectum with or without anomalies of the urogenital tract. Posterior sagittal anorectoplasty (PSARP) and minimally invasive laparoscopically assisted anorectal pull-through (LAARP) procedure are now mainly used to surgically treat ARMs. Magnetic resonance imaging (MRI) is the modality of choice for interval follow-up assessment of structural and functional outcome after these surgeries to assess future bowel continence.

Well-developed pelvic musculature has been found to be a reflector of better anal continence after ARM surgery. Thus, MRI plays an important role in evaluating the external sphincter complex, puborectalis, and levator ani muscles. Other parameters that need to be noted include the position of the neoanus, rectal diameter, anorectal angle, presence or absence of megarectum, and other ancillary anomalies in the spine.

Thus, MRI due to superior soft-tissue resolution is the modality of choice and indispensable for post-operative pelvic evaluation in children.

Anorectal malformations: Role of MRI in preoperative evaluation

PURPOSE

To evaluate the spectrum of magnetic resonance imaging (MRI) findings in pediatric patients with anorectal malformation (ARM) and compare the accuracy of MRI and distal cologram (DC) findings using surgery as reference standard.

MATERIALS AND METHODS

Thirty pediatric patients of age less than 14 years (19 boys and 11 girls) with ARM underwent preoperative MRI. MRI images were evaluated for the level of rectal pouch in relation to the pelvic floor, fistula, and development of sphincter muscle complex (SMC). Associated spinal and other anomalies in lumbar region and pelvis were also evaluated. DC was done in 26 patients who underwent colostomy. Ultrasound of abdomen and pelvis was also done for associated anomalies.

RESULTS

Overall accuracy of MRI and DC to detect the exact level of rectal pouch including cloacal malformation was 93.33% and 76.9% respectively. MRI and DC could correctly identify presence or absence of fistula in 76.6% and 76.9% cases respectively. MRI and DC correctly identified the anatomy of fistula in 76% and 65% cases respectively. On MRI, correlation of development of levator ani and puborectalis with the level of rectal pouch as found on surgery was significant (P = 0.008; 0.024 respectively). Subjective assessment of sphincter muscle development on MRI correlated well with the surgical assessment [P = 0.019 and 0.016 for puborectalis and external anal sphincter (EAS) respectively]. Lumbosacral spine anomalies were present in 33.3% of patients and were most common in high type of ARM. Vesicoureteric reflux and renal agenesis were the most common renal and urinary tract anomalies and were present in 40% of cases.

CONCLUSION

MRI allows reliable preoperative evaluation of ARM and should be considered as a complementary imaging modality for preoperative imaging in ARM.

Minimally Invasive Surgery in the Management of Anorectal Malformations

Imperforate anus, a variant of anorectal malformation (ARM), is a common congenital anomaly requiring surgical attention in the newborn period. It may present with a variety of anatomic configurations, largely dependent on the presence and location of a fistula. The location (or characteristics) of a fistula, which usually lies between the gastrointestinal tract and the genitourinary tract or perineum, is often used in determining the type and timing of operative management. This article discusses the work-up and management, modes of treatment and their postoperative outcomes, and continued controversy regarding the use of minimally invasive surgical approaches to ARM.

Whole exome sequencing of sporadic patients with Currarino Syndrome: A report of three trios

Currarino Syndrome is a rare congenital malformation syndrome described as a triad of anorectal, sacral and presacral anomalies. Currarino Syndrome is reported to be both familial and sporadic. Familial CS is today known as an autosomal dominant disorder caused by mutations in the transcription factor MNX1. The aim of this study was to look for genetic causes of Currarino Syndrome in sporadic patients after ruling out other causes, like chromosome aberrations, disease-causing variants in possible MNX1 cooperating transcription factors and aberrant methylation in the promoter of the MNX1 gene. The hypothesis was that MNX1 was affected through interactions with other transcription factors or through other regulatory elements and thereby possibly leading to abnormal function of the gene. We performed whole exome sequencing with an additional 6Mb custom made region on chromosome 7 (GRCh37/hg19, chr7:153.138.664-159.138.663) to detect regulatory elements in non-coding regions around the MNX1 gene. We did not find any variants in genes of interest shared between the patients. However, after analyzing the whole exome sequencing data with Filtus, the in-house SNV filtration program, we did find some interesting variants in possibly relevant genes that could be explaining these patients` phenotypes. The most promising genes were ETV3L, ARID5A and NCAPD3. To our knowledge this is the first report of whole exome sequencing in sporadic CS patients.

European Society of Paediatric Radiology abdominal imaging task force recommendations in paediatric uroradiology, part IX: Imaging in anorectal and cloacal malformation, imaging in childhood ovarian torsion, and efforts in standardising paediatric uroradiology terminology

At the occasion of the European Society of Paediatric Radiology (ESPR) annual meeting 2015 in Graz, Austria, the newly termed ESPR abdominal (gastrointestinal and genitourinary) imaging task force set out to complete the suggestions for paediatric urogenital imaging and procedural recommendations. Some of the last missing topics were addressed and proposals on imaging of children with anorectal and cloacal malformations and suspected ovarian torsion were issued after intense discussions and a consensus finding process that considered all evidence. Additionally, the terminology was adapted to fit new developments introducing the term pelvicalyceal dilatation/distension (PCD) instead of the sometimes misunderstood hydronephrosis. The present state of paediatric urogenital radiology was discussed in a dedicated minisymposium, including an attempt to adapt terminology to create a standardised glossary.

Magnetic resonance imaging of fetal pelvic cysts

The detection of fetal anomalies has improved in the last years as a result of the generalization of ultrasound pregnancy screening exams. The presence of a cystic imaging in the fetal pelvis is a relatively common finding, which can correspond to a real congenital cystic lesion or result from the anomalous liquid accumulation in a whole pelvic organ, mainly the urinary bladder, the uterus, or the vagina. In selected cases with poor prognosis and/or inconclusive echographic findings, magnetic resonance may bring additional information in terms of the characterization, anatomical location, and real extension of the pathology. This pictorial essay describes the normal pelvic fetal anatomy, as well as the most common pelvic cysts. It also describes the causes of an anomalous distension of the whole pelvic organs detected in utero, with emphasis on prenatal magnetic resonance imaging exams. Moreover, it proposes practical teaching points to reduce the differential diagnosis of these lesions based on the sex of the fetus, the division of the pelvis in anatomical spaces, and the imaging findings of the pathology. Finally, it discusses the real utility of complementary MRI.

Syndromic anorectal malformation associated with Holt-Oram syndrome, microcephaly, and bilateral corneal opacity: a case report

BACKGROUND

The occurrence of an anorectal malformation with Holt-Oram syndrome, microcephaly, and bilateral corneal opacity is rare and to the best of our knowledge has not previously been reported in the literature. Hence, there is a need to document our experience in this case and learn as much as possible from it.

CASE PRESENTATION

We present the case of a Nigerian female neonate with a postnatal diagnosis of syndromic anorectal malformation associated with Holt-Oram syndrome, microcephaly, and bilateral corneal opacity. The infant had successful staged correction of her anorectal malformation but developed a metastatic Wilms' tumor and died before other corrective procedures could be instituted.

CONCLUSIONS

An anorectal malformation is here reported to occur with Holt-Oram syndrome, an association that has not been reported previously. To enhance the prognosis and quality of life of children with syndromic anorectal malformation, prenatal ultrasound monitoring of high-risk pregnancies and expertise in prenatal detection of congenital anomalies are invaluable in antenatal care.

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.

High resolution MRI for preoperative work-up of neonates with an anorectal malformation: a direct comparison with distal pressure colostography/fistulography

Objective

To compare MRI and colostography/fistulography in neonates with anorectal malformations (ARM), using surgery as reference standard.

Methods

Thirty-three neonates (22 boys) with ARM were included. All patients underwent both preoperative high-resolution MRI (without sedation or contrast instillation) and colostography/fistulography. The Krickenbeck classification was used to classify anorectal malformations, and the level of the rectal ending in relation to the levator muscle was evaluated.

Results

Subjects included nine patients with a bulbar recto-urethral fistula, six with a prostatic recto-urethral fistula, five with a vestibular fistula, five with a cloacal malformation, four without fistula, one with a H-type fistula, one with anal stenosis, one with a rectoperineal fistula and one with a bladderneck fistula. MRI and colostography/fistulography predicted anatomy in 88 % (29/33) and 61 % (20/33) of cases, respectively (p = 0.012). The distal end of the rectal pouch was correctly predicted in 88 % (29/33) and 67 % (22/33) of cases, respectively (p = 0.065). The length of the common channel in cloacal malformation was predicted with MRI in all (100 %, 5/5) and in 80 % of cases (4/5) with colostography/fistulography. Two bowel perforations occurred during colostography/fistulography.

Conclusions

MRI provides the most accurate evaluation of ARM and should be considered a serious alternative to colostography/fistulography during preoperative work-up.

Key Points

• High-resolution MRI is feasible without the use of sedation or anaesthesia.

• MRI is more accurate than colostography/fistulography in visualising the type of ARM.

• MRI is as reliable as colostography/fistulography in predicting the level of the rectal pouch.

• Colostography/fistulography can be complicated by bowel perforation.

Imaging findings in Down syndrome

Down syndrome, or trisomy 21, is the most common chromosomal anomaly and is characterized by intellectual disability and a typical facies. People with Down syndrome can have abnormalities of multiple organ systems. Cardiac and respiratory system involvement is the most common cause of morbidity and mortality, although every organ system can be affected. Patients may present prenatally with findings on screening sonography. If the diagnosis is not made prenatally, it is apparent at birth because of the characteristic facial features and musculoskeletal findings. Children with Down syndrome present to the radiology department at various ages depending on the severity of the specific finding. The purpose of this paper is to review the most common antenatal and postnatal imaging findings of Down syndrome as they manifest throughout the body.