Identification of an occult recto-prostatic fistula with cystoscopy-assisted air colostogram.

INTRODUCTION: Anorectal malformations (ARM) in newborns classically present with the absence of a normal anus or an abnormally located anus. In a male infant with a high ARM, an initial diverting colostomy is later followed by a definitive posterior sagittal anorectoplasty (PSARP). Prior to definitive surgery an augmented-pressure colostogram is performed to identify the location of the fistula between the rectum and urogenital tract. However, on occasion, the augmented-pressure colostogram fails to identify the location of the fistula tract. We present a case of ARM where augmented-pressure colostogram failed to identify a fistula tract, thus requiring an alternative diagnostic approach.

PRESENTATION OF CASE: A newborn male presented with a high anorectal malformation and suspected rectourinary fistula on initial augmented-pressure colostogram. The patient ultimately underwent a laparoscopic assisted PSARP after cystoscopy with air colostogram identified the exact location of the fistulous connection in the prostatic urethra.

DISCUSSION: Augmented-pressure colostogram remains the gold standard in diagnosing rectourinary fistulae in cases of ARM. However, a number of alternative and adjunctive techniques have been proposed in recent years. We provide a brief review of the literature in addition to a case presentation highlighting the potential benefits of pre-operative cystoscopy-assisted air colostogram in male patients with ARM.

CONCLUSION: Cystoscopy-assisted air colostogram via a distal mucous fistula can be utilized as an alternative diagnostic modality, especially when the augmented-pressure distal colostogram fails to identify rectourinary fistulae in high anorectal malformations.