Females with Externally Visible but Stenosed Fecal Orifice - Low or High Anorectal Malformation.

We report four female children with externally visible but stenosed fecal orifice which proved to be a high anorectal malformation (Type IV pouch colon). They were managed by an abdominoperineal approach with excellent results. We emphasize the correct recognition of this pathology.

Introduction

A female baby with bowel opening into the vestibule or perineum is generally classified and managed as a low malformation. Pouch colon, even of Type IV variety, needs an abdominal approach. We report four female children with apparently low but stenotic fecal orifice, which on investigation proved to be Type IV congenital pouch colon (CPC) and were managed by a combination of abdominal and anterior sagittal anorectoplasty (ASARP) approaches. We highlight the clinical features, investigations, and management of this group of malformations which, if correctly done, yield excellent results. Unrecognizing it would result in a failed ASARP procedure.

Materials and Methods

This is a retrospective study of four female children with pouch colon but had an externally visible but stenotic anal orifice.

Case 1

A 1-month-old female child was brought with straining to pass stool and absent anal orifice. On clinical examination, there was a vestibular fistula. Contrast enema showed a dilated rectum above the PC line [Figure 1]. The perineum was exposed as in ASARP and adequate mobilization could not be done from this approach. Laparotomy revealed a dilated sigmoid colon with an abrupt transition to the normal caliber proximal sigmoid colon. The dilated pouch was resected, and normal bowel was pulled through the muscle complex. The baby was stable and started stooling well from the 1st postoperative day and started on oral fluids on the 2nd postoperative day and is stooling well. At 4 months of age, the child passes motion five times a day.

Figure 1

Contrast enema – done through an externally visible stenotic orifice in Cases 1–4. All show pouch like termination of the colon with narrow fistula to the exterior. Case 3 in addition has a vaginal H-fistula

Case 2

A 3-month-old female child was brought with constipation and a narrow vestibular fistula. Examination of the abdomen revealed a loaded bowel, and hence, X-ray and contrast enema were done. Contrast enema showed lower sigmoid dilatation [Figure 1 - Case 2]. As satisfactory wash out could not be done, a colostomy was done above a typical Type IV pouch colon. After 3 months, resection of the pouch and pull through of colostomy was done by the abdominoperineal approach. The baby is stable and stooling well after 2 years.

Case 3

A neonate was referred on D20 of life with a history of passing stool through the vagina. The baby was detected to have a narrow but normally sited anal orifice and was straining to pass stool. Dilatation done elsewhere afforded no relief, and then, some stool was noted from the vagina. She was referred with a diagnosis of anal stenosis with rectovaginal fistula. Contrast study showed H fistula with loaded Type IV pouch colon [Figure 1 - Case 3]. In addition, the baby had a distended bladder with bilateral ureterohydronephrosis (UHN). A colostomy above the pouch was performed with relief of symptoms. After 3 months, excision of the pouch along with stenotic anal canal with the H-fistula was done. At that time, a septate vagina was also noted. The colostomy site was brought down with a combined ASARP and abdominal approach. The child also underwent bilateral ureteric reimplantation for refluxing ureters and a Mitrofanoff for possible neurogenic bladder secondary to partial sacral agenesis. Currently, At 2 years of age, she is stooling and voiding normally with a resolution of UHN.

Case 4

A newborn was brought with vestibular fistula, abdominal distension and Type IV pouch colon [Figure 1 - Case 4], ectopic ureter on the left side with septate vagina. An end colostomy followed by excision of the pouch and pull through of the colostomy was done. The ectopic ureter was reimplanted. At 10 years of age, she is doing well without any urinary or bowel incontinence.

Discussion

CPC accounts for 6%–13% of all anorectal malformations (ARMs) in Northern India.[123] Low ARM with fistula into the vestibule or perineum is common in female children, and most of these can be managed by a perineal approach.

Low anorectal anomalies with pouch colon have been reported rarely. Type IV CPC has the presence of near-normal colon with only the terminal portion of colon (sigmoid and rectum) converted into a pouch.[4] This could be associated with an externally visible fecal orifice and hence mistaken for a low malformation. According to the Krickenbeck classification,[5] three of our patients were vestibular fistula and one was a rare variant with H-type rectovaginal fistula with stenotic anal orifice and all four were associated with CPC.

A perineal approach alone in these cases will be insufficient management.

The hallmark of this association is early-onset abdominal distension often from the neonatal period. This distension, caused by fecal impaction, is unrelieved by attempted dilatation or wash out. Thus, a contrast study through the perineal orifice is imperative before rational management can be instituted. In our four cases, the contrast study demonstrated a high-level dilated bowel in the form of Type IV pouch colon. This pouch is unsuitable for colostomy or as pull through neorectum. Thus, a diverting colostomy or definitive pull through of the bowel proximal to the pouch has to be performed. The transition between the pouch and normal proximal sigmoid colon is abrupt which is typical of pouch colon. At its distal termination, the pouch had a long stenotic passage to the perineum either to the vestibule or to the anus. One child in addition had H-fistula with vaginal duplication. We feel that the fistula into the vagina was congenital rather than traumatic as it opened into the septum between the vaginae and it remained unchanged after a diverting colostomy.

A positive feature in this group of female children is a well-developed sphincter complex in the perineum. In this regard, they resembled low malformation and had near-normal fecal control provided that healthy proximal bowel above the pouch was brought down as the neo rectum. Three of them underwent colostomy followed by abdominoperineal pull through and one patient underwent single-stage abdominoperineal pull through (Krickenbeck surgical procedure classification).[6]

Associated genitourinary malformation was present in two of these four female children. The bladder outflow obstruction with bilateral refluxing ureters in Case 3 was partly due to impacted feces in the pouch and partly due to sacral agenesis. She has improved remarkably after excision of the pouch.

In conclusion, we emphasize that in females, an apparently low malformation could be in reality a high ARM which needs to be recognized and appropriately treated.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.