Imperforate Anus Rapid Fire: Update Course 2015

In vestibular fistulas where the opening is very close to the expected anal position, the perineal anatomy can improve significantly within a few weeks to a month, with the distance from the expected anus decreasing over time.

As long as the child is stooling adequately, there is no urgency to perform definitive repair, and waiting at least a month to observe anatomic evolution is appropriate.

Management of vestibular fistulas varies widely among pediatric surgeons, with some performing dilations, some doing primary operations, and some doing colostomies.

Expert surgeons may be able to perform primary repair in the newborn period, but routine pediatric surgeons may not have the same capability.

Primary repair in a newborn is technically challenging because it is hard to identify where the sphincter should be and the dissection plane between vagina and rectum is much thinner.

In settings without access to TPN and IV fluids where anoplasty healing is critical, colostomy with delayed repair may be more appropriate than primary repair.

Prolonged dilations cause scarring and inflammation that can make subsequent surgical repair more difficult.

Dilations should typically be limited to size 7 or 8, with patients maintained on stool softeners.

Dilations up to size 11 or 12 make subsequent repair technically difficult.

Dissection at 3 or 6 months of age can be just as tedious as newborn repair if dilations have caused local trauma.

Conservative postoperative management includes keeping patients NPO for about a week and providing hyperalimentation (a 'medical colostomy'), though there is no data to support this approach.

The primary reason for not operating in the immediate newborn period is the technical difficulty of the dissection, not concerns about stool sterility.

It is harder to identify the exact center of the sphincter in a 2 kg baby than in an 8 or 9 kg baby.

In a patient with vestibular fistula and absent vagina who has good prognosis for bowel control, the operation should either be aborted for later definitive planning, or a graft (colon or small bowel) can be used to replace the vagina while bringing the rectum/fistula down as a pull-through.

In a patient with vestibular fistula and absent vagina who has poor prognosis for bowel control (such as those with sacral agenesis, tethered cord, or other conditions), the rectum/fistula can be used as the vagina and a more proximal piece of colon brought down as the pull-through.