Pictorial essay: Distal colostography

Abstract

Distal colostography (DC), also called distal colography or loopography, is an important step in the reparative management of anorectal malformations (ARMs) with imperforate anus, Hirschsprung's disease (occasionally) and colonic atresia (rarely) in children and obstructive disorders of the distal colon (colitis with stricture, carcinoma or complicated diverticulosis) in adults. It serves to identify/confirm the type of ARM, presence/absence of fistulae, leakage from anastomoses, or patency of the distal colon. We present a pictorial essay of DC in a variety of cases.

Keywords: Imperforate anus; imaging of anorectal malformations; pouch colon.

Figure 1

Blind end of rectum with faecal residue. The rectum is greatly distended and extending above the level of ischial tuberosities and so suggestive of an intermediate type of ARM. It is also significantly loaded with meconium / faecal residue (arrow marks rectum)

Figure 2

Recto–bladder neck fistula (arrow). The distal colostogram shows that the distal colon opens into the bladder neck and so this is a high type of ano-rectal malformation. (R: rectum and B: bladder)

Figure 3

Recto-prostsatic urethral fistula. The DC shows that the distal colon is opening into the prostatic urethra. The contrast is refluxing proximally into bladder and also getting micturated. This is associated with a high type of ARM. (R: Rectum, B: bladder and arrow points to recto - prostatic urethral fistula)

Figure 4 (A, B)

Recto-vaginal fistula. The DC reveals that the distal colon is opening into upper end of the vagina, making this a high type of ARM. Anteroposterior view shows opacification of the fornices. Arrows in 4A mark the vaginal fornices. (R: rectum, V: vagina)

Figure 5

Recto- (bulbar) urethral fistula. The DC shows that the distal rectum is communicating with bulbar urethra and distal urethra is opacified. The urethra is kinked acutely at the site of fistula (marked by an arrow). This is an intermediate type of ARM

Figure 6

Recto-vaginal fistula. The rectum is opening into lower part of vagina (marked by an arrow) and so is associated with an intermediate or low type of ARM

Figure 7

Recto-perineal fistula: The distal colon is opening at the base of a hypospadiac penis (marked by an arrow). A metallic marker was placed over the base of penis on dorsal aspect (marked by arrowhead). This is associated with a low type of ARM. (P: penis)

Figure 8

Cloaca in a female child. The DC shows rectum and uterus opening into a common chamber of cloaca marked by an arrow head. The contrast filled the common chamber and vaginal cavity (marked by an arrow), while it was not filing bladder retrogradely. The urethral opening was also noticed to be inside the cloaca

Figure 9

Pouch colon with cloaca. At surgery, the entire colon was absent except for a rectal pouch, into which the terminal ileum was opening. Hence an ileostomy was performed. Only a single opening of the cloaca was noted. The ileostomogram instead of a distal colostogram in this 2-year-old female child opacifies the common chamber of the cloaca (thick arrow) and shows the fistula (arrowhead) (P - pouch colon). The terminal ileum is seen as well (thin arrow)

Figure 10

Colostomy for Hirschprung's disease. Some pediatric surgeons carry out colostomy in early management of Hirschprung's disease. DC in a child in whom colostomy was carried out for a significantly narrow aganglionic segment (marked by an arrow) confirmed the diagnosis. Note that the proximal colon looks small after defunctioning colostomy

Figure 11

DC for checking the lumen of distal colon. : DC shows leakage of contrast from the site of anastomosis after resection of a malignant growth of recto sigmoid in an old person. Based on this observation the closure of colostomy was deferred for some more time