Colorectal Quiz Episode 28: Female ARM Management - Perineal Fistula

Conversations about female perineal fistula management are more time-consuming than those about cloaca, and patients seek multiple opinions for this relatively benign malformation.

If the hole is in the center of the sphincter with adequate lumen and a perineal body is present, the patient does not need surgery.

If the hole is too small or outside of the sphincter, surgery is required.

There are five valid management options for perineal fistula: colostomy then repair, primary repair, dilation then repair, simultaneous colostomy and repair, and dilation alone.

Diverting with a colostomy does not necessarily prevent perineal body dehiscence, and colostomy carries significant morbidity including closure complications.

Dilation alone is potentially acceptable but could be problematic if the fistulous distal end will not grow, leading to proximal distension.

Anal stenosis (position 5 on the classification) requires screening for Currarino syndrome.

A vestibular fistula is not a vaginal fistula because the posterior vaginal wall is intact with no fistula to it.

True vaginal fistulas are exceedingly rare in anorectal malformations.

Some perineal fistulas (position 4 on the classification) can be managed with posterior wall mobilization without touching the anterior wall.

Many children with anorectal malformations have associated genitourinary anomalies, which is well documented in the literature.

During vaginoscopy, seeing a single cervix does not definitively mean only one cervix is present; a second may be found later if there is a narrow side.

Surgeons performing vaginoscopy should look for single versus duplicated cervix, distal vaginal atresia, and vaginal septum.

The incidence of distal vaginal atresia is quite rare in anorectal malformations.

Vaginal septums occur in approximately 3 to 5% of vestibular fistulas.

Perineal fistulas can be associated with distal vaginal atresia, though less commonly than vestibular fistulas.

When neurologic anomalies are found in anorectal malformation patients, gynecological anomalies are more likely, especially on the same side.

For patients with anorectal malformations and ureteral abnormalities, differential renal function assessment (such as DMSA scan) is important to determine whether to reimplant the ureter or remove a non-functional kidney.

Absent kidneys in anorectal malformation patients are usually not truly absent but rather non-functional, often multicystic and dysplastic.

Every surgeon caring for anorectal malformations should know the malformation type, spinal status (tethered cord, myelomeningocele, or normal), and sacral anatomy including sacral ratio.

Sacral ratio calculation is valuable for informing family conversations about potential for bowel control in anorectal malformation patients.

A patient with a low-type anorectal malformation (such as perineal fistula) but with associated spinal pathology has a different prognosis for bowel control than the same malformation with a normal spine.