Contrast-enhanced Colonosonography in AnoRectal malformations (CoCo-ARM) study

Fluoroscopic colostography (FC) is the gold-standard modality to plan definitive surgery in anorectal malformation (ARM). Contrast-enhanced colosonography (CeCS) can be used in this context. We conducted a prospective, single-centre study comparing the accuracy of CeCS with FC.

Male patients with ARM awaiting reconstructive surgery were recruited during a 12-month period. CeCS using SonoVue were performed and reported contemporaneously by two investigating consultant radiologists. FCs were performed departmentally. All studies were reported as anonymised, unlinked studies by a third blinded consultant. The anonymised studies were reported with a Likert score to denote confidence in the findings. Findings were compared between the two imaging techniques and at operation.

11 patients were included. There was agreement in 8/11 (73%) patients between the two modalities. Beaking was seen at FC without a clear fistula in 2 cases, but was demonstrated clearly on CeCS. In the eleventh case, FC demonstrated a potential perineal fistula; there was poor filling of the distal limb using initial CeCS. This study was repeated under GA combined with cystoscopy, clearly identifying a recto-prostatic fistula. There was agreement in 100% of cases during blinded review of the CeCS with a mean Likert rating of 1.6 (SD = 0.64). In 10/10 (100%) of those who have undergone reconstructive surgery, CeCS findings were consistent with operative findings.

CeCS is equivalent, if not superior to, FC in accurately identifying the fistular anatomy in males with anorectal malformations. Studies can be reviewed and reported with a high degree of diagnostic confidence.