H. Etskovitz1, M. Arsam Haroon1, B. Hsi Dickie1, P. Nandivada1 1Boston Children’s Hospital, Surgery, Boston, MASSACHUSETTS, USA
Introduction: Children suspected to have an anterior ectopic anus are commonly referred to colorectal surgery clinics for medical and/or surgical intervention. It can be difficult to differentiate between anterior ectopic anus and perineal fistula that is partially encircled by the sphincter complex. The purpose of this study was to examine the natural history of children referred for evaluation of ectopic anus, with attention to the incidence of constipation requiring treatment, association with VACTERL anomalies, and need for surgery.
Methods: We performed a retrospective review of a cohort of 31 patients referred for evaluation of anterior ectopic anus from 2017 to 2022. Data collected included: age, sex, symptoms described at clinic visit, physical exam findings, diagnosis of VACTERL anomalies, need for medical management of constipation, and need for operation (either exam under anesthesia (EUA) or posterior sagittal anorectoplasty (PSARP)). Results are expressed as percentages of the entire cohort.
Results: Of the 31 patients referred for evaluation of anterior ectopic anus, 3 (9.7%) had a normal perineal exam at initial visit and no further follow up was recommended. 17 (54.8%) patients experienced constipation, with 38.7% requiring regular laxative use and 6.5% requiring enema use. 32.3% of patients underwent dilations. 7 (22.6%) patients with persistent constipation on laxatives or enemas underwent an exam under anesthesia (EUA) with muscle stimulation to better delineate the position of the anal opening within the sphincter complex. The average time from initial presentation to EUA was 26 months. 2 (6.5%) patients had an EUA that demonstrated less than 50% of the anal opening within the sphincter complex and subsequently required a limited PSARP. Of the 2 patients that required surgical repair, 1 patient experienced mild post-operative rectal prolapse. Both patients have well controlled constipation on laxatives. Concomitant VACTERL anomalies, defined in Table 1, were present in 7 (22.6%) patients. Of those patients, 4 (42.9%) had cardiac anomalies, 2 (28.6%) had renal anomalies, and 1 (14.3%) had esophageal atresia. None of the patients in the cohort had spinal anomalies or spinal cord tethering.
Conclusion: Over half of the children with anterior ectopic anus have clinically significant constipation requiring laxative and/or enema therapy and benefit from long term follow up. Renal and cardiac anomalies are not uncommon and all patients with concern for anterior ectopic anus should be screened. In equivocal cases, exam under anesthesia ruled out perineal fistula about 70% of the time and surgical reconstruction was not recommended.
