Anorectal Malformation with Colonic Perforation

Male newborn, born to young, healthy and non-related parents after an observed and uneventful pregnancy. Maternal serologies were negative and the obstetrical ultrasound exams were described as “normal”. A vaginal delivery occurred at 36 weeks and 6 days. The Apgar scores were 9/10 (1^st and 5^th minutes, respectively). The somatometry at birth was adequate for gestational age, with a birth weight of 3180g. At 24 hours of life he started frequent episodes of gastric regurgitation associated with food refusal, without dejections. At the physical examination a distended and painful abdomen was evident and in the perineal region a pustule in the median raphe was attached to a small orifice, without anal orifice. The remaining exam didn't reveal any changes, including other congenital anomalies. The abdominal radiographs (anteroposterior and profile) confirmed the diagnosis of anorectal malformation with perineal fistula complicated with pneumoperitoneum (Figures 1 & 2). He was submitted to an exploratory laparotomy (with sigmoid colonic raffia) and posterior sagittal anorectoplasty, with a favorable clinical outcome.

Figure 1: Thoraco-abdominal radiograph showing extensive pneumoperitoneum.

Figure 2: Profile tangential chest radiograph showing free intra-abdominal air, as well as air delimitating the intestinal wall both internally and externally (Rigler’s sign).

Anorectal malformations include a set of congenital defects generated from the 5^th to 8^th weeks of gestation. They occur in approximately 1 per 3000 live births and are more frequent in males [1]. Physical examination of the perineum is often sufficient for the diagnosis. However, delay in diagnosis is not uncommon. Spontaneous perforation of the colon is a rare complication estimated to occur in 2% of neonates, but rises to 9.5% when the diagnosis is delayed [2]. The perforation of the colon is the most frequent cause of pneumoperitoneum seen in the neonatal age group. Bowel perforation increases the neonatal mortality from 3% to 23% [3].

An early diagnosis of anorectal malformation is of great importance, allowing a timely treatment and avoiding the associated complications.

1. Cuschieri A (2001) Descriptive epidemiology of isolated anal anomalies: A survey of 4.6 million births in Europe. Am J Med Genet 103: 207-215.
2. Turowski C, Dingemann J, Gillick J (2010) Delayed diagnosis of imperforate anus: An unacceptable morbidity. PediatrSurg Int 26:1083-1086.
3. Raveenthiran V (2012) Spontaneous perforation of the colon and rectum complicating anorectal malformations in neonates. J Pediatr Surg 47: 720-726.