Diagnosis and management of a remnant of the original fistula (ROOF) in males following surgery for anorectal malformations

Abstract

Purpose: A complication of the surgical management of anorectal malformations (ARMs) is a retained remnant of the original fistula (ROOF) formerly called a posterior urethral diverticulum (PUD). A ROOF may have multiple presentations or may be incidentally discovered during the work-up of ARM after previous surgery. We sought to define the entity and the surgical indications for excision of a ROOF when found.

Methods: We performed a retrospective cohort study of all male patients who presented to our center following previous repair for ARM at another institution, who came for evaluation of problems with urinary and/or fecal continence, from 2014 to 2017. Charts were reviewed for symptoms, original type of malformation, preoperative imaging, treatment, and postoperative follow-up.

Results: Of 180 referred male patients, 16 had a ROOF. 14 underwent surgical repair to address this and for other redo indications, and 2 did not require intervention. 13 patients had an additional reason for a redo such as anal mislocation or rectal prolapse. Indications for ROOF excision were urinary symptoms (e.g. UTI, dribbling, passage of mucous via urethra, stone formation), to make a smoother posterior urethra for intermittent catheterization, or for prophylactic reasons. Patients were repaired at an average age of 4.2 years, using a PSARP only approach with excision of the ROOF for all except one patient who needed a laparotomy due to abdominal extension of the ROOF. No patient needed a colostomy. The original ARM repairs of the patients were PSARP (9), laparoscopic assisted (4) and abdominoperineal pullthrough (3). Preoperative evaluation included pelvic MRI, VCUG, and cystoscopy. The ROOF was visualized on 14 of 16 MRIs, 10 of 14 VCUGs, and 14 of 15 cystoscopies. Urinary symptoms associated with a ROOF and ease of catheterization were improved in all repaired cases.

Conclusion: Patients not doing well from a urinary or bowel standpoint post ARM pull-through need a complete evaluation which should include a check for a ROOF. Both modalities MRI and cystoscopy are needed as a ROOF can be missed on either alone. A VCUG was not reliable in identifying a ROOF. Excision is needed in patients to improve urinary symptoms associated with these lesions and to minimize the small but theoretical oncologic risk present in a ROOF.

Level of evidence: Level III.

Keywords: Anorectal malformation (ARM); Posterior sagittal anorectoplasty (PSARP) reoperation; Posterior urethral diverticulum (PUD); Remnant of original fistula (ROOF).