Analysis of 1,992 patients with anorectal malformations over the past two decades in Japan. Steering Committee of Japanese Study Group of Anorectal Anomalies

Sonographic features of anorectal atresia at 12 weeks

We present the sonographic features of a fetus with anal atresia at 12 weeks of gestation. Follow-up ultrasound examination at 17 week revealed apparently normal bowel. Spontaneous miscarriage occurred at 18 weeks and postmortem examination showed anorectal atresia and arthrogryposis multiplex. It seems that dilatation of the bowel in the early pregnancy is a possible marker for anorectal atresia, and the abnormality may be overlooked if a mid-trimester scan alone is performed.

Utility of spinal MRI in children with anorectal malformation

BACKGROUND

The association between spinal cord anomalies and imperforate anus is well recognized. Until now, the incidence of tethered cord has been assumed to be higher in patients with high-type imperforate anus. However, recent reports suggest that tethered cord is as common in patients with a low lesion as in those with a high lesion.

OBJECTIVE

To review the incidence of spinal cord anomalies in those with a low lesion and those with a high (including intermediate) anorectal malformation (ARM), and to determine the best diagnostic imaging strategy.

MATERIALS AND METHODS

A group of 50 consecutive patients with postoperative ARM and in whom spinal MRI had been performed were identified retrospectively. We reviewed and compared the following factors between those with a high lesion and those with a low lesion: (1) clinical symptoms, (2) spinal cord anomalies, and (3) vertebral anomalies.

RESULTS

The incidence of spinal cord anomalies was no different between those with a high lesion and those with a low lesion, and spinal cord anomalies were present regardless of the presence of vertebral anomalies or symptoms.

CONCLUSION

Owing to the high incidence of spinal cord anomalies in patients with imperforate anus, MRI is the best imaging tool for detecting such anomalies regardless of the level of the lesion.

Congenital gastrointestinal anomalies in anorectal malformations: what relationship and management?

To date, no systematic review of gastrointestinal anomalies associated with anorectal malformations has been performed. We report the management of three challenging cases of neonates affected by congenital gastrointestinal and anorectal malformations and we review the pertinent published reports to disclose the incidence and outcome of this combination. In 3951 anorectal malformations, the incidence of digestive tract anomalies was approximately 15%. The association of multiple congenital gastrointestinal defects strongly increased the case complexity and worsened the outcome. Based on our study, the application of a rational and staged management plan provides easier diagnosis and treatment of complex cases. Moreover, keeping in mind the likely co-occurrence of anorectal and gastrointestinal anomalies could help avoid misdiagnosis and prevent life-threatening complications. Finally, the knowledge of this association and its successful management can help the multi-specialist team to become more confident in counselling, diagnosis and treatment.

Nonfluoroscopic pressure colostography in the evaluation of genitourinary fistula of anorectal malformations: experience in a resource-poor environment

BACKGROUND

Radiological imaging is paramount for defining the genitourinary fistulae commonly associated with anorectal malformations prior to definitive surgery. The imaging options are resource-limited in many parts of the world. Nonfluoroscopic pressure colostography after colostomy is a cheap method for the evaluation of anorectal malformations.

OBJECTIVE

To describe our experience with nonfluoroscopic pressure colostography in the evaluation of anorectal malformations in boys.

MATERIALS AND METHODS

The study included 12 boys with anorectal malformation who had colostomy and nonfluoroscopic pressure-augmented colostography with water-soluble contrast medium between January 2006 and December 2007.

RESULTS

Patient ages ranged from 2 days to 1 year. The types of genitourinary fistula were rectovesical (7.7%) and rectourethral (92.3%). Oblique radiographs were of diagnostic value in all patients. The types of anorectal malformations were high, intermediate and low in 75%, 8.3% and 16.7%, respectively. Short-segment urethral constriction was a common feature of rectourethral fistula (75%, n=9).

CONCLUSION

Our experience has shown that genitourinary fistulae associated with anorectal malformations can be demonstrated reliably by nonfluoroscopic pressure colostography with two oblique radiographs, providing an option in resource-poor settings where fluoroscopic equipment is scarce.

The spectrum of anorectal malformations in Africa

Anorectal malformations (ARM) remain a significant birth defect with geographic variation in incidence, individual phenotypes and regional geographic subtypes. Although early studies indicated a low incidence in Black patients, there is a great paucity of knowledge as to the types, frequency and incidence of ARMs encountered in the African continent and their associated anomalies. Current evidence suggests a significant clinical load. This study set out to evaluate ARM in Southern and other parts of Africa to define the clinical load of ARM. We retrospectively collected data on 1,401 ARM patients from six South African Paediatric Surgical units plus representative samples from five other African countries from West, Central and Southern Africa. Data included ethnic group, age, gender as well as the anatomical pathology, classification and presence or absence of associated anomalies. ARM lesions classified by the Wingspread classification plus an analysis of fistula position was carried out in evaluable cases for purposes of comparison. South African centres reported a higher prevalence of cloacae and vestibular fistulae, whereas rectovaginal, recto prostatic and anorectal malformation without fistula were more prevalent in the Northern African group. 76% of 1,401 patients were ethnically Black African [gender ratio = 2 (vs gender ratio 1.38 overall)] and 49.8% were "low" lesions (Wingspread classification). High or intermediate lesions were mostly males (72%). Anal stenosis was most prevalent in black males and non-Black females. Fistulae were identified in 95% with 682 (52%) being low (perineal/covered anus/vestibular) fistulae. Perineal fistulae had a male predilection (n = 260; 20%), whereas vestibular fistulas (n = 416; 32%) was strikingly frequent in black females (55%). Of the remainder, 15 fistulae were rectovesical (1.2%), 544 recto-urethral or prostatic (42%), 16 recto-vaginal (1.2%). In addition, there were 43 cloacal lesions (3.3%). Isolated rare ARM anomalies included "Pouch" colon (2) and H-type fistula (2). Isolated lesions occurred in 81% but 163 associated anomalies were identified in 114 patients. These included chromosomal lesions (10), genito-urinary anomalies (50), genital (16), cardiac (31), skeletal anomalies (33), gastro-intestinal malformations (28). Other anomalies included CNS anomalies (14), anterior abdominal wall defects (2) and facial (8) abnormalities and neuroblastoma (1). The ARM is not uncommon in Black African populations and constitutes a significant clinical load to surgical practice in Africa. Ethnic differences appear to exist and vestibular fistulae predominate in black females. Cloaca (3.3%) did appear to be more prevalent. Isolated lesions are frequent but the types of associated anomalies appear similar to other series except chromosomal syndromes. This study illustrates the need for more objective data from developing countries to assess geographical differences.

Anopenile urethral fistula

A newborn male weighing 3,650 g was born without an anal opening and a perineal fistula. However, an invertography showed rectal gas below the ischium. At the age of 1 day, the patient underwent colostomy. Based on colonourethrography that revealed a fistula between the rectum and the spongy urethra, the patient was diagnosed with an anopenile urethral fistula (APUF). At the age of 7 months, the patient underwent anterior sagittal anorectoplasty (ASARP). The sphincter muscles were divided at the midline. After ligating the fistula, the rectum was pulled through to the anal dimple. At the age of 11 months, a colostomy closure was performed. Consequently, the fistula in the corpus spongiosum penis was not removed. It has been 14 years since the operation was performed, and the patient has had no problems with regard to urination and defecation. According to the embryological studies of the anorectum, APUF could occur due to the following reasons: incomplete descent of the urorectal septum, failed disappearance of the dorsal cloacal membrane, and excessive elongation of the urorectal septum in the phallus. The ASARP provides a superior operative field to identify the fistula and the sphincter muscles. Complete removal of the fistula in the corpus spongiosum penis is unnecessary.

Congenital anomalies of the male urethra

The spectrum of congenital anomalies of the male urethra is presented. The embryologic basis of each anomaly, when known, is discussed. Clinical and imaging features of each entity are presented.

Association of endothelin-beta receptor (EDNRB) gene variants in anorectal malformations

Animal models have demonstrated the role of genetic influences in anorectal malformations (ARM), although the pathogenetic mechanism remains uncertain. A body of collateral evidence points to possible connection with the endothelin-beta receptor (EDNRB) gene and the endothelin system. This study investigates the EDNRB gene in patients with ARM. Resected surgical specimens of terminal colonic tissue were obtained from 14 children (6 males and 8 females) undergoing surgery for ARM correction with ethical permission. DNA samples were screened for mutations in EDNRB. Polymerase chain reaction amplification of 7 exons of EDNRB was followed by heteroduplex single-strand conformation polymorphism analysis. Heteroduplex single-strand conformation polymorphism variants were validated with automated sequencing techniques on polymerase chain reaction products showing conformational variants in acrylamide gel. All investigated patients with ARM showed mobility shift aberrations and polymorphisms in the EDNRB gene. These included one previously described polymorphism in exon 4 (831G/A) seen in association with Hirschsprung disease and 6 novel polymorphisms identified in exons 1 (178G/A), 2 (552C/T and 561C/T), and 3 (702C/T). No aberrant banding patterns were observed. The exon 1 (178 G/A) variation was identified in 2 (50%) of 4 low lesions compared with 1 (1%) of 84 control samples. The exon 3 (702C/T) single nucleotide polymorphism was present in 3 (60%) of 5 of the supralevator lesions being associated with exon 4 (831G/A). The patient with VATER associations including cardiac and limb anomalies had the 831G/A variation only. Analysis revealed statistically significant differences for the polymorphism 178G/A (P < .01, chi2 with Yates correction = 8.24) compared to controls. Potential disease-related mutations were identified in South African patients with ARM, raising the question of its potential role in the pathogenesis of this condition.

Associated malformations in patients with anorectal anomalies

Patients with congenital anorectal malformations (ARM) often have other associated congenital defects. The reported incidence and the types of associated malformations vary between different studies. The purpose of this investigation was to assess the prevalences at birth of associated malformations in patients of a geographically defined population with ARM which were collected between 1979 and 2003 in 334, 262 consecutive births. Of the 174 patients with ARM during the study period, 49.4% had associated malformations. Patients with associated malformations were further classified into groups with nonsyndromic multiple congenital anomalies; chromosomal abnormalities; nonchromosomal syndromes including Townes-Brocks, Walker-Warburg, Ivemark, Fetal alcohol, Klippel-Feil, Pallister-Hall, Facio-auriculo-vertebral spectrum, deletion 22q11.2; sequences, including OEIS, Pierre Robin and sirenomelia; and associations including VATER and MURCS. Malformations of the urogenital system (81.1%) and of the skeletal system (45.5%) were the most common other congenital anomalies occurring with ARM in multiply malformed patients without recognized entities, followed by malformations of the cardiovascular system, the digestive system, and the central nervous system. Weight, length, and head circumference of children with ARM and multiple associated malformations were lower than in controls, as was the weight of the placenta. Prenatal detection by fetal ultrasonographic examination was rarely made in isolated ARM. However, even in multiple associated malformations, prenatal detection by fetal ultrasonographic examination had a low sensitivity, 36%. In conclusion the overall prevalence of malformations, which was close to 1 in two infants, emphasizes the need for a thorough investigation of patients with ARM. A routine screening for other malformations may be considered in patients with ARM, and genetic counseling seems warranted in most of these complicated cases.

Imperforate anus: A relatively common anomaly rarely diagnosed prenatally

OBJECTIVE

Despite the relatively common occurrence of imperforate anus, prenatal diagnosis is rarely reported. In this study, we investigated the presence and diagnosis of imperforate anus along with strategies for improving prenatal diagnosis of the condition.

PATIENTS AND METHODS

Fetuses and infants with imperforate anus who had been examined prenatally by ultrasound at the National Center for Fetal Medicine (NCFM) from 1987 to 2004, were evaluated.

RESULTS

Of 69 cases with imperforate anus, only 11 (15.9%) were diagnosed prenatally, at a median gestation of 18 + 4 (range, 15 + 6 to 35 + 6) weeks. In all 11, dilatations of the rectum or lower part of the bowel were seen. Additional anomalies, most of them diagnosed prenatally, were present in 59/69 (85.5%) of the cases. The most frequent additional anomalies were urogenital (53.6%). The karyotype was abnormal in nine cases (13.0%). A retrospective evaluation of available videotapes of 22 cases of imperforate anus that were not diagnosed prenatally revealed that it was possible to suspect the diagnosis in 11/22 (50%) cases. Sixteen infants were born with imperforate anus without prenatal diagnosis of any abnormality. In total, 31/69 (44.9%) cases were terminated, two (2.9%) died in utero and 12 (17.4%) died postnatally. Twenty-four (34.8%) infants survived, including all 10 with isolated imperforate anus and seven of eight cases with only one additional anomaly.

CONCLUSIONS

The prenatal detection rate of imperforate anus was only 15.9%. Imperforate anus is often associated with other anomalies; in this study, 85.5% had additional anomalies. Prenatal diagnosis makes prenatal counseling possible and facilitates optimized postnatal care. We believe that the prenatal detection rate of imperforate anus could be improved. Examiners should intensify their search for typical findings of imperforate anus especially when other anomalies that frequently accompany this condition are present.

Echogenic foci in the dilated fetal colon may be associated with the presence of a rectourinary fistula

Intraintestinal meconium calcification in the fetus and newborn is a rare finding, occurring in patients with intestinal obstruction. The intraluminal location of the enterolithiasis enables differentiation from calcifications that are secondary to bowel perforation and meconium peritonitis. We report on a term male neonate with VACTERL (vertebral defects, imperforate anus, cardiac anomalies, tracheoesophageal fistula, renal anomalies, limb anomalies) association and rectourethral fistula, in whom enterolithiasis was documented by prenatal ultrasound imaging at 21 weeks' gestation. A review of the literature and a summary of all previously described cases of neonates with intraluminal meconium calcifications are provided. Prenatal ultrasonographic detection of enterolithiasis in fetuses with anal atresia may indicate the presence of an enterourinary fistula.

Anal and ano-urogenital malformations: a histopathological study of "imperforate anus" with a reconstruction of the pathogenesis

Histopathological information about "anorectal malformations" is scarce and the pathogenesis still controversial. Autopsy specimens of 20 human fetuses and newborns with "main" types of the disorder were studied histologically. Supplemented with surgical-anatomical data from the literature and with information from our own and earlier embryological research in animal models as well as from recent observations on the normal development of the human perineum, the study allowed for a new reconstruction of the pathogenesis of the disorder. The histological analysis of the malformations in human fetuses and newborns showed a ventralward deviation of the anal canal as the principal deformity. Ano-urogenital communications and differently structured ectopic anocutaneous canals issued from anywhere between the bladder and the vestibular/urethral orifice (female urethra excluded) and between the orifice and the usual site of the anus, respectively, or they ended blindly, but with a suggestion of lost communication. They occurred isolated or in association with other primary or secondary regional anomalies. Patho-embryological data from animal models revealed that the deviation was caused by defective development of the dorsal cloaca and not by disturbances in a series of fusion processes inside and outside the cloaca, as is currently believed. This mechanism fits well into recent adjustments of ideas about the normal development of the perineum. The cause of the defect is still obscure, but a malfunctioning of cells ingressing from an end-stage primitive streak that affects the dorsal side of the prospective cloaca appears most likely. The data collected permit a new reconstruction of the pathogenesis of anal and ano-urogenital malformations.

Fetal Anal Atresia Presenting as Transient Bowel Dilatation at 16 Weeks of Gestation

Congenital anal atresia is a rare abnormality which in two thirds of the cases is associated with other congenital abnormalities or syndromes. Prenatal diagnosis is usually achieved in cases with coexisting abnormalities. The diagnosis of isolated anal atresia is extremely difficult and can be suspected in the presence of colon dilatation. We present the case of a fetus in which marked dilatation of the colon was diagnosed at 16 weeks of gestation. Four weeks later the sonographic appearance of the bowel was normal and remained normal for the rest of the pregnancy. Anal atresia was diagnosed immediately after birth and corrected surgically. No other abnormalities were present. This case report illustrates that in anal atresia, bowel dilatation may be only transient.

Molecular genetic analysis of a de novo balanced translocation t(6;17)(p21.31;q11.2) associated with hypospadias and anorectal malformation

We report a young boy with penoscrotal hypospadias, anal atresia (AA) with a recto-urethral fistula, a hypoplastic kidney and a balanced translocation t(6;17)(p21.31;q11.2). Physical mapping of the breakpoints localized the chromosome 6 breakpoint within an intron of the gene lipoma HMGIC fusion partner-like 5 (LHFPL5) whereas the chromosome 17 breakpoint was mapped to the first intron of the 182-FIP gene encoding the Fragile X Mental Retardation Protein Interacting Protein. Sequence analysis across the breakpoints revealed an almost perfectly balanced translocation with a 2 bp deletion on the derivative chromosome 6 and a 7 bp duplication on the derivative chromosome 17. We identified a fusion transcript consisting of the first exon of 182-FIP and the last exon of LHFPL5 in patient-derived cells. Quantitative expression analysis of the genes flanking the breakpoints, revealed increased transcript levels for SFRS protein kinase 1 (SRPK1) and TAO kinase 1 (TAOK1) which suggests a positional effect due to the translocation. We hypothesize that the urogenital and anorectal malformations in the patient result from one or several mechanisms including disruption of the genes 182-FIP and LHFPL5, altered expression of the genes flanking the translocation breakpoints and, a gain of function mechanism mediated by the 182-FIP-LHFPL5 fusion transcript.

First-trimester diagnosis of imperforate anus

Imperforate anus or anorectal atresia is often associated with major fetal structural defects but it may also be an isolated abnormality. Prenatal diagnosis is difficult but may be assisted by ultrasound detection of a dilated distal bowel or rectum. We report on a fetus at 12 weeks of gestation in which a dilated colon was detected at ultrasound examination. Dilatation of the colon was clearly seen in the first and third trimesters of pregnancy, but was difficult to detect in the second trimester. At birth, the newborn was diagnosed with a low type of imperforate anus.

Y-type urethral duplication: an unusual variant of a rare anomaly

Urethral duplications are rare anomalies. We present a 3-year-old continent boy passing urine since birth per anus while voiding from penis. Micturating cystourethrogram, retrograde urethrogram and cystoscopy revealed a Y connection between the posterior urethra and anal canal. The accessory channel was excised by a perineal approach. Histopathology revealed that the tract was lined by transitional epithelium, proving that it was indeed a case of urethral duplication; hence, we suggest that all urethroanal fistulas are not variants of anorectal malformations. Certain of these fistulas should be considered as variants of Y-type urethral duplication even if the orthotopic urethra is normal.

Associated congenital anomalies in patients with anorectal malformations--a need for developing a uniform practical approach

BACKGROUND/PURPOSE

The aim of this study was to compare the incidences of various associated anomalies among subjects with high and low anorectal malformation (ARM), study the coexistence of these anomalies, and compare their frequency with those quoted in the existing literature.

METHODS

Ten years of data (from January 1993 through December 2002) on the 416 subjects from our center with anorectal malformations (ARM) were evaluated. The subjects with supra or translevator rectal pouch (radiologic or operative findings) were classified as high ARM and the rest as low ARM. The associated anomalies studied were vertebral, skeletal, renal, cardiac, vesicoureteric reflux (VUR), gastrointestinal, tracheoesophageal fistula, spinal, genital, and miscellaneous. For a detailed comparison, 4 subgroups were made: boys with high ARM, boys with low ARM, girls with high ARM, and girls with low ARM. Statistical methods were used for intergroup comparison.

RESULTS

There were 68% male and 32% female subjects. Overall, 58% of subjects had high ARM (supralevator and translevator). Our attempt to compare the incidences of anomalies in our study population with those in other populations was defeated because of nonuniformity of classification and investigation of these anomalies in different studies. We found a frequent clubbing of anomalies affecting distantly developing anatomic regions in patients with ARM in many studies. The highest incidence of associated anomalies was found among boys with high ARM. The male subjects also had significantly more genital anomalies in association with low ARM and gastrointestinal tract anomalies in association with high ARM. On the other hand, girls had more urologic anomalies with high ARM and VUR with low ARM.

CONCLUSIONS

Except for a low incidence of spinal anomalies (8%) and of VUR (1.7%), the incidences of most associated anomalies in our study were comparable with those of the earlier studies. Additionally, the girls with high ARM were observed to have significantly more urologic anomalies compared with the boys with high ARM in contrast to the results of the earlier reports. The existence of anomalies in distantly developing anatomic regions in patients with ARM supports the possibility of a "generalized" insult during embryogenesis rather than a ("localized") defect. It was observed that the boys with ARM are more likely to suffer morbidity because of frequent occurrence of multiple associated anomalies, and it may be worthwhile to evaluate of the role of sex chromosome in relation to ARM. The authors are also of the view that there is a need for more uniformity in classification of the anomalies and in their diagnostic approach because various reported studies have differed so widely on these aspects that any interstudy comparison is difficult or not feasible.

Associated anomalies with anorectal malformation (ARM)

OBJECTIVE

To find the prevalence of associated anomalies in children with anorectal malformation (ARM).

METHODS

One hundred and forty patients (80 males and 60 females) with expand were studied to detect associated anomalies and to find their prevalence. High and low type of ARM was seen in 52.14% and 47.86% of patients respectively. Associated anomalies were more common with high type of ARM (78.08%) than in patients with low type of ARM (37.31%). 58.57% patients had associated anomalies which included those of urinary system (37.14%), vertebral system (34.28%), skeletal system other than vertebral (15.17%), genital system (14.29%), cardiovascular system (12.14%), gastrointestinal tract (10.7%) and spinal cord (10%).

RESULTS

37.43% patients had 3 or more than 3 components of VACTERL association. Two patients had all six components of VACTERL. Most common association was vertebral, anal and renal anomalies seen in 16 patients.

CONCLUSION

Patients with ARM should undergo a detailed general physical, systemic and radiological examination (infanto-gram, echocardiography, US of urogenital system) in neonatal period to detect associated anomalies in early period.

Double Atresia of the Hindgut with Ileal Stenosis: A Case Report

An unusual case of imperforate anus with sigmoid colonic atresia and ileal stenosis is described. Only six cases of imperforate anus associated with colonic atresia have previously been reported in Japan. The possibility of other alimentary obstructions should thus be considered when anorectal anomalies are observed.

A case of acrocephalosyndactyly with low imperforate anus

The authors report a case of a female acrocephalosyndactyly with imperforate anus without fistula, which is rare in girls. Acrocephalosyndactyly is characterized by premature closure of the sutures (craniosynostosis) and fusion or webbing of hands and feet (syndactyly). The most general types of the syndrome are the Apert syndrome and the Pfeiffer syndrome. They usually have some fibroblast growth factor receptor (FGFR) gene mutations, so that acrocephalosyndactyly is thought to be involved in "FGFR-related craniosynostosis." To the authors' knowledge, only 4 cases of anorectal anomaly in acrocephalosyndactyly have been reported in the world. The relationship between anorectal anomaly and the FGFR gene is not clear now, but might be clarified in the future.

Urorectal septum malformation sequence: Insights into pathogenesis

We characterize the urorectal septum malformation sequence (URSMS) in discordant fetal lambs and relate it to the human syndromes with which URSMS is associated. We found abnormal external genitalia, imperforate anus, and fistulous connections between the rectum, bladder, and vagina. Discordance among the dizygous twins eliminated teratogens as a likely etiologic factor. We summarize the relevant literature and propose a molecular model for the pathogenesis of the URSMS, in which alterations in sonic hedgehog and homeobox genes lead to caudal mesodermal deficiency during blastogenesis.

Sonographic features of anal atresia at 12 weeks

Anorectal atresia results from abnormal development of the anorectal septum. Prenatal diagnosis is difficult but the condition may be suspected by the sonographic demonstration of a dilated colon. We present the sonographic features of a fetus with anal atresia and a ventricular septal defect at 12 weeks of gestation. This case illustrates that a dilated colon may be present in association with fetal anal atresia as early as 12 weeks.

Perineo-pelvic diaphragmatic split: anorectal exstrophy

Anorectal malformations are among the most common congenital anomalies that require neonatal surgery. Although the headlines of anorectal malformations present with a spectrum of defects of this region, generally, imperforate anus and its fistulous or nonfistulous connections are examined. Here the authors present a boy with anorectal malformation, with sacrococcygeal teratoma and meningocele. Interestingly, the patient had neither imperforate anus nor anorectal stenosis, but had widely open anorectum. This kind of anorectal malformation has never been described previously in the English-language literature.