The cloacal malformation: radiologic findings and imaging recommendations

Following a strict renal protection protocol in cloacal malformations: A descriptive analysis

BACKGROUND

In children with cloacal malformations, renal dysfunction is a constant concern, with reported incidence as high as 50%. Multiple factors exist that may impair renal function. Our institution follows a strict renal protection protocol in this population. Incidence of renal dysfunction in these patients is unknown.

OBJECTIVE

We aimed to evaluate incidence of renal dysfunction while implementing this protocol in a cohort of children with cloacal malformation.

STUDY DESIGN

We reviewed a prospectively collected database of children with cloacal malformations managed at a single institution since implementation of a renal protection protocol. This involves regular laboratory evaluation, appropriate selection of total urogenital mobilization or urogenital separation, proactive imaging in patients with signs of impending renal dysfunction or urinary retention, and early catheterization teaching and implementation if necessary. Glomerular filtration rate (GFR) was calculated with the Schwartz formula and CKD grades assigned per standard definitions. Renal dysfunction was defined as CKD grade 3b or higher, need for renal replacement therapy (RRT) or transplantation. Descriptive statistics were computed.

RESULTS

A total of 105 children were managed under this protocol with a median follow-up of 4.2 years [IQR: 2.0-5.9]. Six children (5.7%) had renal dysfunction at most recent follow-up; of these children, only three (2.9%) progressed from normal renal function at initial evaluation to renal dysfunction (Table). No child with normal presenting renal function thus far has progressed to require dialysis or transplantation.

DISCUSSION

Previous literature estimated rates of renal dysfunction in cloaca patients as high as 50%; in contrast, we demonstrate a rate of progression to renal dysfunction of 2.9% in girls following a strict renal protection protocol. Most children who developed renal dysfunction had dysfunctional kidneys on presentation. This suggests that preservation of renal function may be possible in early childhood with a strict, multi-disciplinary renal protection protocol.

CONCLUSION

In our cohort of patients with cloacal malformations following a strict renal protection protocol, incidence of progressive renal dysfunction is low at 2.9%. Most who go on to renal dysfunction present with impaired renal function.

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.

A Spectrum of Ultrasound and MR Imaging of Fetal Gastrointestinal Abnormalities: Part 2 Anorectal Malformation, Liver, and Abdominal Wall Anomalies

Ultrasound (US) and magnetic resonance imaging (MRI) are two modalities for diagnosing fetal gastrointestinal (GI) anomalies. Ultrasound (US) is the modality of choice. MRI can be used as a complementary method. Despite its expanding utilization in central nervous system (CNS) fetal malformation, MRI has not yet been established for evaluation of fetal GI abnormalities. Therefore, more attention should be paid to the clinical implications of MRI investigations following screening by US.

Contrast-enhanced voiding urosonography part 2: urethral imaging

Ultrasound (US) has been increasingly used as an important imaging tool to assess the urethra in children. The earliest reports of pediatric urethral sonography involved imaging the urethra in a non-voiding state, during physiological voiding of urine, and after instillation of saline. The introduction of US contrast agents has continued to improve visualization of urethral anatomy. Contrast-enhanced US of the urethra can be performed during the voiding phase of a standard contrast-enhanced voiding urosonography (ceVUS) exam or with retrograde instillation of a contrast agent, depending on the exam indication. Both techniques are well tolerated by children and provide accurate information about urethral pathology and periurethral soft tissues. This article reviews the technical aspects and imaging findings of urethral pathologies in children using contrast-enhanced US, both by the voiding and retrograde instillation techniques.

Transcending Dimensions: a Comparative Analysis of Cloaca Imaging in Advancing the Surgeon's Understanding of Complex Anatomy

Surgeons have a steep learning capacity to understand 2-D images provided by conventional cloacagrams. Imaging advances now allow for 3-D reconstruction and 3-D models; but no evaluation of the value of these techniques exists in the literature. Therefore, we sought to determine if advances in 3-D imaging would benefit surgeons, lead to accelerated learning, and improve understanding for operative planning of a cloaca reconstruction. Questionnaires were used to assess the understanding of 2-D and 3-D images by pediatric surgical faculty and trainees. For the same case of a cloacal malformation, a 2D contrast study cloacagram, a 3D model rotatable CT scan reconstruction, a software enhanced 3D video animation (which allowed the observer to manipulate the structure in any orientation), and a printed physical 3D cloaca model that could be held in the observer's hand were employed. Logistic mixed effect models assessed whether the proportion of questions about the case that were answered correctly differed by imaging modality, and whether the proportion answered correctly differed between trainee and attending surgeons for any particular modality. Twenty-nine pediatric surgery trainees (27 pediatric general surgery and 2 pediatric urology surgery trainees) and 30 pediatric surgery and urology faculty participated. For trainees, the percentage of questions answered correctly was: 2-D 10.5%, 3-D PACS 46.7%, 3-D Enhanced 67.1%, and 3-D Printed 73.8%. For faculty, the total percentage of questions answered correctly was: 2-D 22.2%, 3-D PACS 54.8%, 3D Enhanced 66.2%, and 3-D printed 74.0%. The differences in rates of correctness across all four modalities were significant in both fellows and attendings (p < 0.001), with performance being lowest for the 2-D modality, and with increasing percentage of correct answers with each subsequent modality. The difference between trainees and attendings in correctness rate was significant only for the 2-D modality, with attendings answering correctly more often. The 2-D cloacagram, as the least complex model, was the most difficult to interpret. The more complex the modality, the more correct were the responses obtained from both groups. Trainees and attendings had similar levels of correct answers and understanding of the cloacagram for the more advanced modalities. Mental visualization skills of anatomy and complex 3-D spatial arrangements traditionally have taken years of experience to master. Now with novel surgical education resources of a 3-D cloacagram, a more quickly advancing skill is possible.

The cloacal anomalies: Anatomical insights through a complex spectrum

PURPOSE

To study the detailed anatomy of cloacal anomalies using the multiplanar capabilities of MRI in addition to other available modalities.

PATIENTS AND METHODS

The study was conducted on 27 cases of cloaca that were managed at our unit during the last 12 years. Preoperative assessment included conventional investigations and MRI studies. Endoscopic and operative findings were important for confirmation and completion of the whole picture. For better perception of the degree of deviation from the norm, we included another control group of girls who underwent pelvic MRI studies for causes other than anorectal anomalies.

RESULTS

For practical reasons, we dissociated the cloacal complex into its two basic components to be described separately namely the anorectal anomaly and persistent urogenital sinus. The anorectal anomaly may be best described regarding two parameters: the position of the rectum and type of rectal communication with the urogenital tract. Persistent urogenital sinus anomalies were stratified based on referring the level of the urogenital confluence to the back of pubic symphysis. Three types could be identified (low, intermediate, and high) in which the mean length of the common channel was 6.4, 14.6, and 24 mm respectively with a significant statistical difference (Kruskal-Wallis chi-squared test).

CONCLUSION

Applying MRI in the preoperative assessment of cases of cloaca has the advantage of demonstrating the real anatomy of the anomaly in multiple planes. This can improve our perception of the degree of deviation from the norm in these cases, which may be important during planning for surgical reconstruction.

LEVEL OF EVIDENCE

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

Ultrasonographic and multimodal imaging of pediatric genital female diseases

Ultrasonography is the first-line imaging modality in the evaluation of the female pelvis in childhood and adolescence, because it is easy to perform, non-invasive and it does not require sedation. The transabdominal approach is preferred in children and adolescents, after filling the bladder to move away the bowel loops from the pelvis. The probe frequency must be adapted to age, thickness of tissues and depth of the structures under examination. High-frequency (4-12 MHz) linear or convex probes are used in newborns; high-frequency linear probes (4-12 MHz) in toddler, convex 5-7.5 MHz probes in girls and convex 3.5-5 MHz probes in teenagers. In this article, the main pathological conditions of the genital female tract in pediatric age are examined, such as congenital anomalies, disorders of sex development, ovarian cysts, ovarian tumors, adnexal torsion, primary amenorrhea, precocious puberty and pelvic inflammatory disease.

Imaging of non-traumatic urinary bladder emergencies

Non-traumatic urinary bladder emergencies are rare but critical diagnoses to make in an emergency setting. Acute urinary bladder pathologies require an accurate and timely diagnosis to ensure a favorable clinical outcome. Multidetector computed tomography (CT) is the imaging modality of choice for acute and emergent conditions affecting the urinary bladder. MRI is helpful as a problem-solving modality due to better soft tissue characterization and higher in-plane resolution. The purpose of this article is to illustrate the spectrum of urinary bladder emergencies, review the imaging findings, and briefly describe the role of imaging in the evaluation of such patients. Although there are a few cases of bladder emergencies been reported separately, the literature summarizing the spectrum is lacking. The objective of this article is to review the imaging of acute emergencies involving urinary bladder that will help us to think beyond non-specific conclusion in an emergency setting. For the sake of focused discussion, traumatic bladder emergencies will be excluded in this review. In the era of highly image reliant clinical practice, radiologists must be familiar with the diagnostic strategy to approach these entities.

Late Diagnosis of Complete Colonic and Rectal Duplication in a Girl with an Anorectal Malformation

Complete colonic duplication is rare, and usually occurs as a part of the caudal duplication syndrome. In such cases, the diagnosis is clinically evident by the presence of two ani arranged side by side in the perineum, which is commonly associated with duplication of the external genitalia as well (double phallus or double vestibule). In this report, we present a special case of anorectal anomaly that was associated with complete tubular colonic duplication. The diagnosis was initially missed due to the uncommon sagittal arrangement of duplicated rectum: one rectum was ending externally into the perineum by rectoperineal fistula, while the other was hidden by its internal termination into the vagina. Our final diagnosis for this case was a variant of anorectal anomaly in the female, which was associated with complete colonic duplication. One colon (which was in the free mesenteric border) terminated anteriorly into the vagina as a part of a "short common channel" cloaca, while the other colon terminated by rectoperineal fistula. Although the anomaly seems to be rather complex and confusing, yet our case was associated with an excellent outcome due to the benign type of anorectal anomalies (rectoperineal fistula and "short common channel" cloaca) and absence of significant sacral dysplasia; in addition to adequate identification of the abnormal anatomy by appropriate investigations and the staged approach for surgical reconstruction.

Persistent cloaca and caudal duplication in a monovular twin, a rare case report

INTRODUCTION

A cloaca occurs when genitourinary tract and bowel converge into a common channel. We report a case of partial caudal duplication, persistent cloaca and vestigial appendage in a monovular female twin infant.

PRESENTATION OF CASE

This is a monochorinonic-diamniotic twin born at 36 weeks with apgars of 9/9. She had a duplicated labia with two clitorises, and a partially formed accessory foot with 2 toes protruding from the right gluteal region. There was anal atresia and a punctate urethral opening in the right genitalia through which she voided spontaneously. X-ray of the accessory foot had rudimentary metatarsals and phalanges. There was left hydroureteronephrosis and a hydrocolpos causing severe mass effect. On the first day of life, she had exploratory laparotomy with a diverting colostomy and mucus fistula and drainage of hydrocolpos. At 6 months of age, she had removal of the accessory foot with flap closure of the perineal defect and vesicostomy. At 15 months of age she had laparotomy for repair of cloaca, excision of presacral pelvic mass and the duplicated vulva.

DISCUSSION

Theories of etiology include failure of regression of Kovalevsky's canal (a communication that connects the amniotic and yolk sac), an incomplete form of twinning through iatrogenic damage to the zona pellucida or a failed triplet formation from a single embryo.

CONCLUSION

Caudal duplication with persistent cloaca and vestigial appendage is a rare and complex malformation. Having a unified surgical and medical team to preserve quality of life and to treat complications is of key importance.

Measuring the common canal of a persistent cloaca: can MRI replace conventional imaging?

AIM

To evaluate the role of MRI in preoperative assessments of patients with a persistent cloaca and compare magnetic resonance imaging (MRI) versus fluoroscopy contrast study in the accuracy of common canal measurement and classification prediction.

MATERIALS AND METHODS

Thirty-one patients with a persistent cloaca were diagnosed and treated at Guangzhou Women and Children's Medical Center between March 2011 and December 2017. The length of the common canal was measured using MRI and fluoroscopy contrast study. Classification results based on measurements were compared with cystoscopy and intraoperative findings. The accuracy in predicting the classification by measuring the common canal length was compared.

RESULT

Among 31 patients, 24 had MRI, 24 underwent fluoroscopy contrast study, and 25 underwent cystoscopy. In 20 patients, MRI-based categorisations were in accordance with cystoscopy or surgery findings, whereas in four patients there was discordance. In 17 patients, categorisations based on fluoroscopy contrast study were in accordance with cystoscopy or surgery findings, and in seven patients there was discordance; the difference was not statistically significant (p>0.05).

CONCLUSION

MRI may accurately demonstrate genitourinary anomalies and the length of the common canal in patients with persistent cloaca. Categorisation based on MRI measurements of the common canal was accordant with the results from cystoscopy and findings from surgery. The use of this method may help surgeons to develop appropriate reconstruction plans before sending their patients to the operating room.

Use of 3D reconstruction cloacagrams and 3D printing in cloacal malformations

INTRODUCTION

Cloacal anomalies are complex to manage, and the anatomy affects prognosis and management. Assessment historically includes examination under anesthesia, and genitography is often performed, but these do not consistently capture three-dimensional (3D) detail or spatial relationships of the anatomic structures. Three-dimensional reconstruction cloacagrams can provide a high level of detail including channel measurements and the level of the cloaca (<3 cm vs. >3 cm), which typically determines the approach for surgical reconstruction and can impact long-term prognosis. Yet this imaging modality has not yet been directly compared with intra-operative or endoscopic findings.

OBJECTIVES

Our objective was to compare 3D reconstruction cloacagrams with endoscopic and intraoperative findings, as well as to describe the use of 3D printing to create models for surgical planning and education.

STUDY DESIGN

An IRB-approved retrospective review of all cloaca patients seen by our multi-disciplinary program from 2014 to 2016 was performed. All patients underwent examination under anesthesia, endoscopy, 3D reconstruction cloacagram, and subsequent reconstructive surgery at a later date. Patient characteristics, intraoperative details, and measurements from endoscopy and cloacagram were reviewed and compared. One of the 3D cloacagrams was reformatted for 3D printing to create a model for surgical planning.

RESULTS

Four patients were included for review, with the Figure illustrating 3D cloacagram results. Measurements of common channel length and urethral length were similar between modalities, particularly with confirming the level of cloaca. No patient experienced any complications or adverse effects from cloacagram or endoscopy. A model was successfully created from cloacagram images with the use of 3D printing technology.

DISCUSSION

Accurate preoperative assessment for cloacal anomalies is important for counseling and surgical planning. Three-dimensional cloacagrams have been shown to yield a high level of anatomic detail. Here, cloacagram measurements are shown to correlate well with endoscopic and intraoperative findings with regards to level of cloaca and Müllerian development. Measurement discrepancies may be due to technical variation indicating a need for further evaluation. The translation of the cloacagram images into a 3D printed model demonstrates potential applications of these models for pre-operative planning and education of both families and trainees.

CONCLUSIONS

In our series, 3D reconstruction cloacagrams yielded accurate measurements of urethral length and level of cloaca common channel and urethral length, similar to those found on endoscopy. Three-dimensional models can be printed from using cloacagram images, and may be useful for surgical planning and education.

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 urography in the pediatric population: a clinical perspective

Diagnostic imaging in pediatric urology has traditionally relied upon multiple modalities based on availability, use of ionizing radiation, and invasiveness to evaluate urological anomalies. These modalities include ultrasonography, voiding cystourethrography, fluoroscopy and radionuclide scintigraphy. Magnetic resonance urography (MRU) has become increasingly useful in depicting more detailed abdominal and pelvic anatomy, specifically in duplex collecting systems, ectopic ureter, ureteropelvic junction (UPJ) obstruction, megaureter and congenital pelvic anomalies. Here we discuss the clinical role of MRU in the pediatric population and its future direction.

Use of rotational fluoroscopy and 3-D reconstruction for pre-operative imaging of complex cloacal malformations

Complex cloacal malformations are associated with a wide spectrum of anatomic defects involving the gastrointestinal, urinary, and gynecologic tracts; the variety and complexity of these defects complicate surgical planning and repair. Rotational fluoroscopy with 3-D reconstruction provides precise anatomic detail, particularly regarding length of the common channel, appearance/location of the vagina(s) and bladder, which facilitates surgical planning and determination of prognosis.

Magnetic Resonance Imaging of Developmental Anomalies of the Uterus and the Vagina in Pediatric Patients

Developmental anomalies of the uterus and the vagina are associated with infertility and miscarriage and are most commonly detected in the postpubertal age-group. These conditions may also present in younger patients as a mass or pain owing to obstruction of the uterus or the vagina. Associated urinary tract anomalies are common, as well. Accurate diagnosis and thorough description of these anomalies is essential for appropriate management; however, evaluation may be difficult in an immature reproductive tract. Magnetic resonance imaging technique pertinent to imaging of the pediatric female reproductive tract is presented and illustrated along with the findings associated with various anomalies.

The clinical relevance of fetal MRI in the diagnosis of Type IV cystic sacrococcygeal teratoma--a review

The introduction of fetal magnetic resonance imaging (MRI) has improved the prenatal evaluation of uterine, placental and fetal anatomy. However, its utilization has mostly been restricted to fetal central nervous system anomalies. We review how adjunct fetal MRI was performed and diagnosis of cystic type IV sacrococcygeal teratoma was made. We also discuss the clinical relevance of fetal MRI in differentiating this lesion from other selected abdominal/pelvic cystic malformations and lesions.

Epidemiology of partial urorectal septum malformation sequence (or 'persistent cloaca'): a population-based study in seven regions of England and Wales, 1985-2010

BACKGROUND

Partial urorectal septum malformation (pURSM) sequence (or 'persistent cloaca') is a rare congenital anomaly characterised by a joining of the urethral, anal, and genital openings into a single common channel. This study describes the epidemiology of pURSM sequence in England and Wales including prevalence, additional anomalies, and pregnancy outcomes.

METHODS

All cases of pURSM sequence prospectively notified to seven congenital anomaly registers in England and Wales during 1985-2010, whether delivered as live births, spontaneous fetal deaths (≥20 weeks' gestation), or elective terminations of pregnancy for fetal anomaly (TOPFA, any gestation), formed this population-based cohort. The risks of spontaneous fetal and infant death were examined by Kaplan-Meier analysis. Differences in prevalence over time, and between regions, were examined by multilevel Poisson regression.

RESULTS

117 cases were recorded among 4,251,241 total births. Six (5%) pregnancies resulted in spontaneous fetal deaths, 53 (45%) in TOPFA, and 58 (50%) in live births. The prevalence was 2.8 (95% CI 2.3 to 3.4) per 100,000 total births, increasing significantly over time (p=0.002) and differing significantly between regions (p=0.005). 77 cases (66%) had at least one additional major congenital anomaly outside the perineum, including 67 (57%) renal, 29 (25%) musculoskeletal, 26 (23%) digestive system, and 24 (21%) cardiovascular anomalies. The risks of spontaneous fetal and infant death were estimated as 8.9% (95% CI 4.1 to 18.8) and 26.3% (95% CI 15.1 to 43.4) respectively.

CONCLUSIONS

This is the largest study of the epidemiology of pURSM sequence. The information will be valuable for families and health professionals whenever a case of pURSM sequence is diagnosed.

US of the pediatric female pelvis

This review presents the normal and pathologic development of the gonads and genitourinary tract and addresses the role of ultrasonography in the diagnosis and management of gynecologic disorders of the pediatric pelvis, including ambiguous genitalia, prepubertal bleeding, primary amenorrhea, pelvic mass, and pelvic pain.

Female pseudohermaphroditism in a prenatally diagnosed cloacal malformation with hydronephrosis, dilated bladder, hydrometrocolpos, and oligohydramnios

OBJECTIVE

To present female pseudohermaphroditism in a prenatally diagnosed cloacal malformation.

CASE REPORT

A 29-year-old, primigravid woman referred for counseling at 17 weeks of gestation because of oligohydramnios and an intra-abdominal cyst in the fetus. The woman was not exposed to any virilizing agent during this pregnancy. She did not undergo any assisted reproductive technology for this pregnancy. Level II ultrasound showed a singleton with fetal biometry equivalent to 16 weeks, oligohydramnios, hydrometrocolpos, dilated bladder, and bilateral hydronephrosis. A diagnosis of cloacal malformation was made. The parents elected to terminate the pregnancy at 18 weeks of gestation. A 196-g fetus was delivered with a distended abdomen, a phallus-like structure, a small perineal opening below the phallus-like structure, and an imperforate anus. At birth, the fetus was misdiagnosed as a male with an imperforate anus and a perineal fistula. Cytogenetic analysis of the cord blood revealed a karyotype of 46,XX. Array comparative genomic hybridization analysis of the fetal tissues revealed no genomic imbalance. The phallus-like structure was an enlarged clitoris and contained accessory phallic urethra.

CONCLUSION

Prenatal diagnosis of cloacal malformation with ambiguous genitalia should be paid attention to avoid misdiagnosis of a male with an imperforate anus and a perineal fistula. Cytogenetic analysis is helpful to determine the sex under such circumstances.

Müllerian duct and related anomalies in children and adolescents

Although many Müllerian duct anomalies do not require treatment, surgical intervention is sometimes necessary to enable sexual activity or to preserve fertility. The identification of these anomalies is important for optimal clinical management or surgical treatment. Magnetic resonance (MR) imaging is a robust method for adequately evaluating and characterizing uterine and vaginal anomalies. The information provided by MR imaging allows for a more complete understanding of the malformation, facilitating management decisions and potentially changing the outcome. In this article, the embryology, classification, and MR imaging findings of Müllerian duct and related anomalies in children and adolescents are reviewed.

Cloacal malformation variants in male

OBJECTIVE

The published surgical literatures have referred only to females as having cloacal defects and the incidence in males is not well established. As during embryogenesis, both sexes have to pass through the stage of a cloaca, there is every chance of development of cloacal anomalies in males also. Here, we are presenting our experience of male cloacal malformations.

METHODS

We identified four cases of male cloaca by reviewing medical records of all anorectal malformation (ARM) patients treated at our institution in the past 19 years. Time of presentation, clinical, radiological, cystoscopic and operative findings, and outcomes were analysed.

RESULTS

Out of 1,837 patients, we identified four cases (0.2 %) of male cloacal variants. All presented after 45 days (range 46 days to 28 years). Three of them had proximal hypospadias, two had a vaginal remnant and cystoscopic evaluation showed the length of the common channel ranged from 0.5 to 8 cm. One patient died of multiple anomalies and the other patients are doing well following reconstruction.

CONCLUSION

None of the male cloacal patients presented in the neonatal period, proximal hypospadias was the common external genital abnormality and half of them had a vagina. Surgical outcome was satisfactory. The scarcity of reported cases of this group is a subject of further research.

Cloacal malformation: embryology, anatomy, and prenatal imaging features

Cloacal malformation is a rare but important anomaly. Prenatal diagnosis is possible with knowledge of the distinctive imaging features. The purpose of this case series is to illustrate characteristic prenatal sonographic and magnetic resonance imaging features of cloacal malformation using imaging from 6 cases seen at a single academic center to augment published data. The imaging feature common to all cases was a central cystic pelvic mass containing a characteristic fluid-fluid level. Additional anomalies include uterine and vaginal duplication, hydronephrosis, and lumbosacral anomalies. Prenatal magnetic resonance imaging showed the absence of the normal T1-hyperintense meconium-filled rectum in all cases. Prenatal diagnosis may affect immediate neonatal care (eg, immediate drainage of hydrocolpos) with an ultimate improved outcome.

Combined 3D rotational fluoroscopic-MRI cloacagram procedure defines luminal and extraluminal pelvic anatomy prior to surgical reconstruction of cloacal and other complex pelvic malformations

PURPOSE

Cloacal anomalies represent one of the greatest surgical challenges in pediatric surgery. A recent advancement in the imaging of these anomalies is 3D rotational fluoroscopic cloacagram. However, a disadvantage is that obstructed lumens and extraluminal soft tissue structures are poorly delineated. We describe the development of a novel imaging technique whereby 3D rotational fluoroscopy is combined with high-resolution 3D pelvic MR imaging.

METHODS

3D rotational fluoroscopic cloacagram was initially performed. Catheters were directed into the urinary bladder, colon, and vagina. Low-osmolality iodinated contrast material mixed with a small amount of gadolinium contrast material was used to distend the catheterized cavities. After securing the catheters in place, patients underwent high-resolution 3D MRI of the pelvis. 3D MRI reconstructions were created.

RESULTS

3D rotational fluoroscopic cloacagram provided excellent luminal definition and accurate measurements of channel/fistula lengths, using intraoperative findings as the reference standard. 3D pelvic MRI measurements were easily and accurately made (using intraoperative and 3D rotational fluoroscopic cloacagram as reference standards), and soft tissue structures outside the lumens of the bladder, vagina, and rectum were well-defined. 3D pelvic MRI was able to identify a small vesicovaginal fistula that was not seen at 3D rotational fluoroscopy.

CONCLUSION

This novel form of preoperative imaging results in excellent delineation channel/fistula lengths, luminal anatomy, and extra-luminal soft tissue structures to aid in operative planning.

Evaluation of the perianal muscular complex in the prenatal diagnosis of anorectal atresia in a high-risk population

OBJECTIVES

To investigate whether sonographic identification of the fetal perianal muscular complex (PAMC) is of value in the prenatal detection of anorectal atresia in a high-risk population.

METHODS

During an 8-year study period, a total of 189 pregnancies at high risk for fetal anorectal atresia were prospectively examined for the presence/absence of the PAMC on axial ultrasound views of the fetal perineum. The prenatal findings were confirmed postnatally or at the time of postmortem examination.

RESULTS

The median gestational age at examination was 27 (range, 15-37) weeks. The PAMC was identified in 175 fetuses, all of which had a normal anorectal canal at the time of delivery or at postmortem examination. The PAMC was not identified prenatally in the 14 remaining cases, and the anus was absent in 11 fetuses with anorectal atresia and in two with urorectal septum malformation sequence. There was one false-positive case, in which the anus was anatomically and functionally normal but ectopically located, opening into the vaginal vestibule. Among these 14 cases of anorectal malformation, prenatal dilatation of the distal bowel was seen in nine (64.3%) and intraluminal calcified meconium or enterolithiasis in five (35.7%). Overall, absent PAMC on prenatal sonography in this high-risk population had a sensitivity of 100%, specificity of 99%, true-positive rate of 93% and false-positive rate of 7% for the diagnosis of anorectal atresia.

CONCLUSIONS

In a high-risk population, the absence of PAMC seems to be a highly sensitive and specific sonographic marker for anorectal atresia. The role of routine sonographic identification of the PAMC at the second-trimester scan to screen for cases of isolated anal atresia remains to be determined.

Complex cloacal malformations: use of rotational fluoroscopy and 3-D reconstruction in diagnosis and surgical planning

A cloacal malformation is a congenital malformation in which the urinary tract, gynecological system and distal rectum fail to separate and form a common channel with a single perineal opening. Precise anatomical information is required to plan surgery and predict prognosis for children with this abnormality. Conventional fluoroscopic studies provide limited information, primarily due to the overlap of structures and inability to make accurate measurements. Rotational fluoroscopy and 3-D reconstruction help clarify overlapping structures and allow for precise measurement of the common channel, thereby helping to predict the complexity of the surgical case as well as the long-term prognosis regarding bowel, bladder and sexual function.

Postnatal imaging of neonates with prenatally diagnosed genitourinary abnormalities: a practical approach

The advent of prenatal US and, more recently, fetal MRI has changed our pattern of referrals. In the current clinical algorithms, most neonates evaluated for genitourinary abnormalities are asymptomatic. These infants are referred for multidisciplinary consultation, imaging and surveillance. Evaluation of these children commences following pertinent review of available prenatal studies; this is appropriate, as in certain instances prenatally gathered information of potential prognostic significance can be inferred or can obviate the need for multiple examinations. US remains the first-line imaging modality for diagnosing urinary abnormalities in neonates and young infants, although it offers primarily morphological assessment. However, US coupled with MAG-3 scanning results in a powerful combination that provides anatomical and functional information. Recently, MRI and MR urography have been increasingly regarded as one-stop-shop examinations that can deliver both anatomical and functional information, and play an increasing role in the evaluation of ureteral ectopia and genital anomalies. Fluoroscopic examinations are reserved to exclude vesicoureteral reflux, to delineate urethral obstruction or to provide additional information to support a diagnosis. A practical approach to postnatal imaging of the neonate is discussed and the important genitourinary anomalies in this age group are presented and illustrated.

Fetal MRI clues to diagnose cloacal malformations

BACKGROUND

Prenatal US detection of cloacal malformations is challenging and rarely confirms this diagnosis.

OBJECTIVE

To define the prenatal MRI findings in cloacal malformations.

MATERIALS AND METHODS

We performed a retrospective study of patients with cloacal malformations who had pre- and post-natal assessment at our institution. Fetal MRI was obtained in six singleton pregnancies between 26 and 32 weeks of gestation. Imaging analysis was focused on the distal bowel, the urinary system and the genital tract and compared with postnatal clinical, radiological and surgical diagnoses.

RESULTS

The distal bowel was dilated and did not extend below the bladder in five fetuses. They had a long common cloacal channel (3.5-6 cm) and a rectum located over the bladder base. Only one fetus with a posterior cloacal variant had a normal rectum. Three fetuses had increased T2 signal in the bowel and two increased T1/decreased T2 signal bladder content. All had renal anomalies, four had abnormal bladders and two had hydrocolpos.

CONCLUSION

Assessment of the anorectal signal and pelvic anatomy during the third trimester helps to detect cloacal malformations in the fetus. The specificity for this diagnosis was highly increased when bowel fluid or bladder meconium content was identified.

Newborn with persistent cloaca presenting with accessory phallic urethra and ambiguous genitalia

Persistent cloaca is a rare urogenital anomaly that can pose significant challenges for adequate diagnosis and management. We describe the case of an infant girl with a cloacal malformation, having a single perineal orifice and an accessory phallic urethra, who presented with ambiguous genitalia at birth. The distal part of the accessory phallic urethra was used to create a mucosa-lined vestibule as a part of the total urogenital sinus mobilization. This technical maneuver allowed a more natural looking, and possibly functioning, vaginal introitus, improving the final cosmetic result.

3-Dimensional magnetic resonance genitography: a different look at cloacal malformations

PURPOSE

Standard contrast genitography and endoscopy have been the cornerstone of preoperative investigation of anatomy in complex cloacal malformations. In many cases standard genitography is ambiguous and lengthy endoscopy may be required to define the anatomy. Nonenhanced magnetic resonance imaging lacks definition of the nondistended common channel and confluence. To our knowledge we introduce 3-dimensional magnetic resonance genitography for delineating the unique anatomical features of these complex anomalies.

MATERIALS AND METHODS

Contrast genitography, endoscopy and 3-dimensional magnetic resonance genitography were performed preoperatively in 4 female infants with cloacal malformations. Three-dimensional magnetic resonance genitography was performed using a 3-dimensional spoiled gradient technique after the instillation of gadolinium-diethylenetetramine pentaacetic acid solution via the common channel and cutaneous vesicostomy, when present. Augmented pressure distal colostogram with gadolinium via the mucous fistula was included. Three-dimensional images were constructed using a commercially available workstation.

RESULTS

Three-dimensional magnetic resonance genitography yielded anatomical information far superior to that of standard genitography in all cases and it provided information on female genital tract anomalies and hindgut confluence that were not fully appreciated at initial endoscopy. The confluence was most accurately represented by augmented pressure colostogram. The length of the common channel was consistent with that on endoscopy. Rotating 3-dimensional images illustrated the unique anatomical relationships. No magnetic resonance imaging specific complications were observed.

CONCLUSIONS

Three-dimensional magnetic resonance genitography provides superior anatomical detail for the preoperative assessment of cloacal malformations. It augments the information obtained by standard magnetic resonance imaging of the pelvic organs, levators and lumbosacral spine. Three-dimensional magnetic resonance genitography has great potential as a standard for preoperative anatomical evaluation and it will likely simplify preoperative endoscopy rather than supplant it.

Pre- and postnatal imaging of a girl with a cloacal variant

We describe the prenatal MR findings in a 29-week fetus with a cloacal variant (urogenital sinus and anterior placed anus) in combination with an enlarged clitoris and urethral duplication and correlate them with postnatal imaging. Fetal MR imaging permits the diagnosis and characterization of cloacal and urogenital sinus malformations in utero. This information may guide pre-, peri- and postnatal management.

Prenatal diagnosis of fetal hydrometrocolpos secondary to a cloacal anomaly by magnetic resonance imaging

Fetal female urogenital anomalies are often difficult to evaluate by ultrasonography, especially in late gestation. We report a case of fetal hydrometrocolpos detected at 35 weeks of gestation. Ultrasonography revealed a large retrovesical septate hypoechogenic mass in the fetal abdomen, however the sonographic findings were inconclusive. Magnetic resonance imaging (MRI) confirmed that the abdominal mass was fluid-filled with a mid-plane septum in the midline posterior to the bladder, and showed a connection to the dilated uterus that was duplicated. These findings were consistent with a diagnosis of hydrometrocolpos with septate vagina and uterus didelphys. The neonate showed abdominal distension, ambiguous genitalia and anal atresia with a single perineal opening. Hydrometrocolpos was secondary to a urethral type of cloacal anomaly. Aspiration of the mass and a colostomy were performed on the first postnatal day, followed by anorectoplasty at 19 months of age. MRI is a useful complementary tool for assessing fetal urogenital anomalies when ultrasonography is inconclusive.

Cloacal anomaly simulating megalocystis in the first trimester

We present a case of cloacal anomaly that simulated megalocystis in the first trimester of gestation of a female fetus. During the second trimester, repeated paracentesis was necessary to treat increasing ascites, oligohydramnios, and hydronephrosis. Our data support findings that ascites presenting with a multiloculated cystic structure on sonography during the second trimester may be typical for cloacal anomalies. Active treatment of the fetal ascites is recommended to improve the child's prospects for survival.

Urogenital sinus, rectovaginal fistula, and an anterior stenosed anus--another cloacal variant

The persistent cloaca is one of the most complex and challenging developmental malformations. It is a rare anomaly occurring only in the female newborn and is represented by the association of urogenital sinus with an anorectal malformation (ARM). Each case is probably unique. We report here one such case of cloaca with the VATER association-tracheoesophageal fistula (TOF) with a urogenital sinus, rectovaginal fistula, and an anteposed stenosed anus, along with preaxial syndactyly of the right hand. The spine, renal, and cardiac systems were normal. Interim management was directed towards repair of the TOF and a right transverse defunctioning colostomy. Despite thorough radioendoscopic preoperative investigations, the complexity of the cloacal anomaly was not delineated until surgery. This case is a rather rare combination of an intermediate form of the cloacal-ARM spectrum. Such patients present with many diagnostic and therapeutic problems. Interval surgery should be directed towards decompression of the affected organ systems, and definitive surgery must be carefully planned and, whenever possible, done in a single stage with simultaneous multisystem repair to correct all significant malformations related to the cloacal complex.

Anomalies of the distal ureter, bladder, and urethra in children: embryologic, radiologic, and pathologic features

Congenital anomalies of the lower urinary tract are a significant cause of morbidity in infancy. Radiologic investigation is an important source of clinical information in lower urinary tract disorders but should not inconvenience the patient, expose the patient to unnecessary radiation, or delay surgical correction. In pediatric patients with suspected underlying urologic structural anomalies, screening ultrasonography is commonly the initial diagnostic study. If dilatation of the urinary tract is confirmed, voiding cystourethrography is performed to determine the presence of vesicoureteral reflux (VUR) and other causes of upper tract dilatation. If VUR is confirmed, follow-up with nuclear cystography or echo-enhanced cystosonography may be performed. If VUR is excluded, nuclear diuresis renography is the primary test for differentiating between obstructed and nonobstructed megaureter. Intravenous urography can be used to specifically identify an area of obstruction and to determine the presence of duplex collecting systems and a ureterocele. Computed tomography and magnetic resonance (MR) imaging are unsuitable for general screening but provide superb anatomic detail and added diagnostic specificity. MR imaging is mandatory in the evaluation of associated spinal anomalies. MR urography can demonstrate ectopic extravesical ureteric insertions, thereby providing a global view of the malformation. Familiarity with anomalies of the lower urinary tract is essential for correct diagnosis and appropriate management.

Magnetic resonance imaging in children with anorectal malformations: embryologic implications

PURPOSE

The aim of this study was to evaluate the spectrum of developmental anomalies in the caudal region of patients with anorectal malformations (ARM) and relate them to the new insights in the embryogenesis of this region.

METHODS

Forty-nine patients with ARM were investigated with magnetic resonance imaging (MRI); 24 preoperatively (preop) and 25 postoperatively (postop). Of this group, 17 patients had a high (or intermediate) ARM, 28 a low ARM, and 4 a cloacal malformation (CM). The evaluation of the imaging studies included the level and type of ARM (preop); the developmental state of the sphincter muscle complex (SMC); and the associated anomalies of spinal cord, spine, and urogenital system. The anomalies detected were ordered and related to recent embryologic observations in the caudal region.

RESULTS

With MRI, the level of ARM was depicted effectively in 23 of 24 patients (96%) investigated preop, including 5 of 9 clinically proven fistulae in those with high ARM and CM (56%). Maldevelopment of the SMC was observed in 14 of 49 patients (29%). Associated anomalies of spinal cord and spine were found in 51% of patients, more frequently in those with high ARM, low ARM with fistulae, and cloacal malformations. Associated anomalies of the urogenital system were found in 37% of patients.

CONCLUSIONS

As illustrated by the current study, MRI has become indispensable for the visualization of the nature of congenital ARM and associated anomalies. Moreover, MRI aids in understanding the morphology and pathogenesis of these complex congenital malformations. Based on the MRI and recent embryologic observations, a new and simplified classification of ARM is introduced, including a more appropriate nomenclature.