Imperforate Anus: Determination of Type Using Transperineal Ultrasonography

Abstract

ObjectiveThis study was designed to assess the usefulness of transperineal ultrasonography (US) for the determination of imperforate anus (IA) type.Materials and MethodsFrom January 2000 to December 2004, 46 of 193 patients with an IA underwent transperineal US prior to corrective surgery. Sonographic findings were reviewed to identify the presence of internal fistulas and to determine "distal rectal pouch to perineum (P-P)" distances. IA types were determined based on the sonographic findings, and the diagnostic accuracy of transperineal US was evaluated based on surgical findings.ResultsOf the 46 patients, 17 patients were surgically confirmed as having a high-type IA, three patients were confirmed as having an intermediate-type IA and 26 patients were confirmed as having a low-type IA. The IA type was correctly diagnosed by the use of transperineal US in 39 of the 46 patients (85%). In 14 of the 17 patients with a high-type IA, internal fistulas were correctly identified. All cases with a P-P distance > 16 mm were high-type IAs and all cases with a P-P distance < 5 mm were low-type IAs.ConclusionTransperineal US is a good diagnostic modality for the identification of internal fistulas in cases of high-type IA and for defining the IA level.

Diagnostic Accuracy of Sonography for Detection of a Fistula on the Birth Day in Neonates With an Imperforate Anus: Comparison of Diagnostic Performance Between Suprapubic and Perineal Approaches

“…Previous studies have also reported that sonography facilitates establishment of the location of an internal fistula in patients of various ages with an imperforate anus. Kim et al reported on the use of sonography via the perineal approach on infants with a mean age of 1.1 months and could identify the internal fistulas correctly in 16 of 19 patients (84.2%).…”

“…Kim et al reported on the use of sonography via the perineal approach on infants with a mean age of 1.1 months and could identify the internal fistulas correctly in 16 of 19 patients (84.2%). Choi et al also used the perineal approach in a study of infants with a mean age of 3.5 months and reported that all cases of rectoprostaticurethral fistulas were diagnosed correctly, whereas 14 of 17 cases with a high‐type imperforate anus were correctly identified (sensitivity, 82%). They also identified 1 of 2 rectobulbarurethral fistulas and 13 of 19 cases with anocutaneous or anovestibular fistulas correctly (sensitivity, 68%).…”

“…Sonography has been reported to be useful for differentiating the type of imperforate anus based on the distance between the distal rectal pouch and the perineum and the location of the internal fistula . However, previous sonographic studies included children of various ages and used various sonographic approaches, such as suprapubic and perineal approaches.…”

Comparison of Diagnostic Accuracy for the Low‐Type Imperforate Anus Between Prone Cross‐Table Radiography and Sonography

“…Along with the pouch‐perineum distance, the fistula location was also used to classify the type . If the distal side of the fistula was skin, perinea, or the vestibulum, the type of imperforate anus was diagnosed as low, as previously described . If the distal side of the fistula was the urethra, vagina, or bladder, the type was diagnosed as intermediate or high, as previously described …”

“…Prone cross‐table radiography should be performed 20 to 24 hours after the initial examination to allow time for intraluminal pressure in the rectal pouch to increase . Previous studies have shown that sonography is useful for classifying the imperforate anus type both by establishing the distance between the distal rectal pouch and the perineum (pouch‐perineum distance) and by establishing the location of the fistula . However, to the best of our knowledge, there have been no reports comparing the accuracy of diagnosing the imperforate anus type by using prone cross‐table radiography versus sonography.…”