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

Ultrasonographic Findings of the Penguin's Beak Sign in Neonates With Anorectal Malformation

In the ultrasound for anorectal malformation, penguin's head represents distal rectal pouch, and its beak runs toward distal side of fistula. Despite the rarity of this disease and insufficient ultrasound experience of the examiner, this sign is useful for ultrasound examiners to accurately diagnose the type of anorectal malformation.

[Developmental disorders of the gastrointestinal tract]

BACKGROUND

Developmental disorders of the gastrointestinal tract comprise a broad spectrum of congenital malformations of different etiologies and locations from the mouth to the anus.

METHODS

The authors present the most important malformations of the gastrointestinal tract on the basis of basic and current reviews.

RESULTS

Gastrointestinal developmental disorders occur both sporadically and in connection with malformation syndromes. Symptoms are highly variable and range from postnatal emergencies to asymptomatic abnormalities, which may be incidental radiological findings. Prenatal ultrasound examinations can often identify gastrointestinal developmental disorders at an early stage. Here, fetal magnetic resonance imaging can be a useful addition to the diagnostic process. In the first few days of life, simple X‑ray overview images, supplemented by images after the administration of contrast medium, are often sufficient.

CONCLUSION

Many patients with a malformation of the gastrointestinal tract require lifelong medical care, so that not only pediatric radiologists need specific knowledge about this group of diseases.

Incidence and diagnostic performance of ultrasound for perianal abscess or fistula-in-ano in pediatric patients with perianal inflammation

OBJECTIVES

To describe the incidence and diagnostic performance of ultrasound for perianal abscess or fistula-in-ano in pediatric patients with perianal inflammation.

METHODS

We included 45 patients with perianal inflammation who underwent ultrasonography. To demonstrate the diagnostic performance of ultrasound for fistula-in-ano, a definite diagnosis of perianal abscess, and fistula-in-ano was determined as that proven through magnetic resonance imaging (MRI) or computed tomography (CT). The absence or presence of perianal abscess and fistula-in-ano on ultrasonography was recorded.

RESULTS

Among the 45 patients, on ultrasound, perianal abscess and fistula-in-ano were detected in 22 (48.9%) and 30 (68.2%) patients, respectively. Nine patients had MRI or CT and a definite diagnosis of perianal abscess or fistula-in-ano; accuracy, negative predictive value, and positive predictive value of ultrasound for perianal abscess were 77.8% (7/9; 95% confidence interval [CI]: 40.0%-97.1%), 66.7% (2/3; 95% CI: 9.4%-99.2%), 83.3% (5/6; 95% CI: 35.9%-99.6%), and those of fistula-in-ano were 100% (9/9; 95% CI: 66.4%-100%), 100% (8/8; 95% CI: 63.1%-100%), and 100% (1/1; 95% CI: 2.5%-100%), respectively.

CONCLUSIONS

Perianal abscess and fistula-in-ano were detected by ultrasound in half of the patients with perianal inflammation. Accordingly, ultrasound has an acceptable diagnostic performance for perianal abscess and fistula-in-ano.

Ultrasonic Diagnosis of Intestinal Obstruction in Neonates-Original Article

BACKGROUND

Intestinal obstruction in neonates is a common problem that requires prompt diagnosis and treatment, and ultrasound could be a potential tool for it. The purpose of this study was to investigate the accuracy of ultrasonography in diagnosing and identifying the cause of intestinal obstruction in neonates, the corresponding ultrasonic manifestations, as well as to utilize the diagnostic method.

METHODS

We conducted a retrospective study of all neonatal intestinal obstruction in our institute between 2009 and 2022. The accuracy of ultrasonography in the diagnosis of intestinal obstruction and the identification of its etiology was compared with the results of operation as the gold standard.

RESULTS

The accuracy of the ultrasonic diagnosis of intestinal obstruction was 91%, and the accuracy of the ultrasonic etiological diagnosis of intestinal obstruction was 84%. The main ultrasound findings for the neonatal intestinal obstruction were dilation and high tension of the proximal bowel and collapse of the distal intestinal. Other major manifestations were the presence of corresponding diseases causing intestinal obstruction at the junction of the dilated and collapsed bowel.

CONCLUSIONS

Ultrasound has the advantages of being a flexible multi-section dynamic evaluation and a valuable tool to diagnose and identify the cause of intestinal obstruction in neonates.

The role of ultrasound to evaluate the disorders of sex development: a pictorial essay

Ultrasonography is usually the first modality used to evaluate patients with disorders of sex development (DSD). To determine the sex in patients with DSD, the following four categories are carefully evaluated: chromosomal, gonadal, anatomical internal genitalia, and external genitalia. However, in the clinical setting, the only information that sonographers have prior to ultrasound examination is the appearance of the external genitalia. The following DSD presentations are commonly observed: (1) male external genitalia present at birth, without testis in the scrotum or with a small penis; (2) female external genitalia present at birth, with an inguinal hernia or clitoromegaly; (3) neonates with ambiguous genitalia at birth; and (4) female or male external genitalia without sexual maturity. In this retrospective study of several clinical cases, we demonstrated an ultrasound-based sex determination approach for these clinical presentations. We found that sonographers evaluated the external genitalia in relation to the distal urethra within the corpus spongiosum and corpus cavernosum and the presence or absence of follicles within the detected gonads to determine the sex of the patient.

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%.

Risk factors for anorectal and associated malformations in German children: A 10-year analysis

BACKGROUND

Incidences of anorectal malformations (ARM) occur in 1 of 2000-5000 live births and up to 64% have associated malformations (ARMa). The aim of the study was to evaluate possible prenatal risk factors for ARM in a tertiary hospital.

METHODS

A case-control design was used to compare risk factors in ARM (n = 44) to a control group (CG; n = 26). We used modified prenatal questionnaires, analyzed mothers' prenatal records and participants completed a structured interview. Endpoints were medical history, drug consumption, occupational risk factors, and time point of diagnosis, associated malformations and sensitivity of radiological imaging.

RESULTS

Our results showed that ARM couples had a significantly higher age difference (p = 0.028) compared to CG. ARM mothers had more abnormalities during pregnancy (p = 0.002), more positive vaginal smears of group B streptococci (p = 0.024), urogenital infections (p = 0.005), gestosis (p = 0.03), emesis (p = 0.025) and higher numbers of chronic diseases (p = 0.018). ARM mothers took less medication during pregnancy (p = 0.013) than CG mothers including folic acid (p = 0.041); their intake of iodine tablets was significantly higher (p = 0.035) and they continued smoking for longer (p = 0.036) than CG mothers, and they had more stillbirths (p = 0.035). In using illegal drug and alcohol use, the groups did not show significant differences. ARMa was present in 68.1% (n = 30), of which 45.5% were of urogenital origin (n = 20). ARM diagnosis was made on the first day of life in 72.7% (n = 32), while diagnosis was delayed in 12 patients (27.3%).

CONCLUSION

A combination of different risk factors seem to be associated with the development of ARM, which takes place at an early stage (<7th week) of pregnancy. Therefore, risk factors influencing fetal development must be critically considered. We advocate an interdisciplinary assessment in unclear clinical findings on first day of life to optimize the therapy and positively influence the outcome.

Radiology of anorectal malformations: What does the surgeon need to know?

Imaging is extremely important throughout all phases of care provided to children with anorectal malformations (ARM). A preoperative determination of the patient specific malformation will help establish the operative plan. Moreover, the majority of ARM patients will have an associated anomaly that will require imaging workup for full understanding of those abnormalities prior to addressing the ARM. The complexity of ARM care will mandate continued imaging throughout the post-operative period even in those with straight forward malformations.

Comparison of diagnostic accuracy for fistulae at ultrasound and voiding cystourethrogram in neonates with anorectal malformation

BACKGROUND

Recently, it has been reported that anorectal malformation with rectourethral fistula in male neonates can be managed by primary neonatal reconstruction without colostomy. To prevent urethral injury during anorectoplasty, the fistula's location is important. To date, the use of voiding cystourethrograms to determine the presence and location of fistulas in neonates with anorectal malformations has not been studied.

OBJECTIVE

To compare the accuracy of ultrasound (US) and voiding cystourethrogram for determining the presence and location of fistulas in neonates with anorectal malformation.

MATERIALS AND METHODS

We included 21 male neonates with anorectal malformation with rectourethral fistula (n=16), rectovesical fistula (n=1) or no fistula (n=4) who underwent US and voiding cystourethrogram preoperatively on the day of surgery. Fistula imaging was classified into three grades (0-2), and grades 1-2 were considered fistula positive. We compared the imaging-based location of the fistula with surgical findings.

RESULTS

US performed significantly better than voiding cystourethrogram for determining the presence of fistulas (area under the receiver operating characteristic curve, 0.90 vs. 0.71, respectively; P=0.044) (diagnostic accuracy 85.7%, 95% confidence interval [95% CI] 63.7-97.0% and 52.4%, 95% CI 29.8-74.3%, respectively). In cases with fistulas detected by either modality, the accuracy of locating the fistula by US was 50.0% (95% CI 24.7-75.3%) and by voiding cystourethrogram was 100% (95% CI: 59.0-100%).

CONCLUSION

US accurately detected, but did not accurately locate, fistulas in neonates with anorectal malformation. When planning primary neonatal reconstruction of anorectal malformation without colostomy, voiding cystourethrogram could provide additional information about fistula location.