Colonic atresia is a rare cause of intestinal obstruction and accounts for less than 10% to 15% of all cases of intestinal atresia (Sturim and Ternberg, 1966; Coran and Eraklis, 1969; Bowles et al., 1976; Powell and Raffensperger, 1982; Touloukian, 1993a). Colonic atresia was first recognized in 1673 by Bininger (Powell and Raffensperger, 1982). The first survivor with this condition, treated by colostomy, was not reported until 1922 (Gaub, 1922). Potts (1947) was the first to report a survivor after primary anastomosis. Few series of appreciable size have been reported subsequently because of the rarity of isolated colonic atresia or stenosis (Philippart, 1986). The pathogenesis is thought to be similar to the mechanism responsible for jejunoileal atresia and stenosis (see Chapter 73). The majority of colonic atresias, which occur proximal to the splenic flexure, include a significant segment of absent colon with distal microcolon (Rescorla and Grosfeld, 1985). Anomalies associated with colonic atresia are unusual, but can include gastroschisis and jejunal atresia, Hirschsprung’s disease, as well as ocular and skeletal anomalies (Bowles et al., 1976; Powell and Raffensperger, 1982; Rescorla and Grosfeld, 1985; Jackman and Brereton, 1988; Etensel et al., 2005; Draus et al., 2007). The skeletal anomalies most often seen with isolated colonic atresia include syndactyly, polydactyly, absent radius, and clubfoot (Philippart, 1986). Major cardiac anomalies and genetic defects are rare, although they have been reported (Robertson et al., 1994). Colonic atresias may be seen as a complicating factor in abdominal wall defects such as gastroschisis, omphalocele, or vesicointestinal fistulas (Bowles et al., 1976; Powell and Raffensperger, 1982). Hirschsprung’s disease has also been reported to occur in association with colonic atresia (Johnson and Dean, 1981). However, it is important to remember that in two-thirds of the cases, colonic atresia occurs as an isolated defect without associated abnormalities. Multiple colonic atresias have been reported but are extremely rare (Touloukian, 1993b).

The classic demonstration by Louw and Barnard (1955) that jejunal atresia results from an in utero mesenteric vascular accident is widely accepted and is thought to also apply to colonic atresia. Vascular compromise may occur as a result of a primary vascular accident in utero, or it may be secondary to a mechanical event, such as intestinal volvulus. Because colonic atresia, proximal and distal to the splenic flexure, differs, the cause may also differ in these regions. Other cases of colonic atresia have been reported due to internal hernia, compression of the tranverse mesocolon by a choledochal cyst, or in association with gastroschisis (Etensel et al., 2005; Al Wafi et al., 1998; Basaran et al., 2002). Rare causes of colonic atresia include those attributed to multiple intestinal atresias due to disturbed intestinal morphogenesis (Fourcade et al., 2001), fetal varicella infection (Hitchcock et al., 1995), and familial cases (Benawra et al., 1981).

The occurrence rate of colonic atresia has been reported to vary from 1 in 1498 to 1 in 66,000 livebirths (Sturim and Ternberg, 1966; Davenport et al., 1990). The former appears to overestimate the incidence of colonic atresia and the latter is thought to be an underestimate. One in 20,000 appears to be more nearly correct, based on experience at major pediatric surgical centers (Philippart, 1986). In such centers the occurrence rate approximates 1 case per year of isolated colonic atresia or stenosis. The incidence of colonic atresia is equal in males and females. When there are other associated developmental anomalies, the incidence of colonic atresia increases significantly. Within the gastrointestinal tract, however, only gastric atresia is rarer (Philippart, 1986).

The prenatal sonographic appearance of colonic atresia may be indistinguishable from other forms of distal intestinal obstruction. Prenatal diagnosis of colonic atresia may be extremely difficult to make with certainty. The sonographic image in colonic atresia is that of multiple dilated loops of bowel (Figure 74-1). It may be difficult to distinguish dilated loops of small bowel from dilated loops of colon. Polyhydramnios is an unusual finding in isolated colonic atresia and its presence should raise suspicions about a more proximal intestinal obstruction. Perforation may occur proximal to the atresia, with resulting ascites and meconium peritonitis (Agrawala et al., 2005) (Figure 74-2).