Definition: Anorectal anomalies are congenital malformations affecting the development of the anus and rectum. These structural abnormalities occur during fetal development and result in improper formation of the anorectal region, potentially leading to functional impairments in defecation.
Overview: Anorectal anomalies are rare birth defects with an estimated incidence of 1 in 4,000 to 1 in 5,000 live births. They are part of a broader spectrum of congenital anomalies and may occur in isolation or in association with other developmental abnormalities, most notably as part of VACTERL association (vertebral defects, anal atresia, congenital heart defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities). Diagnosed at birth through physical examination and imaging studies such as X-rays or ultrasonography, these anomalies require surgical intervention for correction, with outcomes depending on the severity and type of malformation.
Etymology/Origin: The term "anorectal" combines "ano-" (referring to the anus) and "rectal" (pertaining to the rectum), derived from Latin anus and rectum ("straight intestine"). "Anomalies" originates from the Greek anÅmalia, meaning "irregularity" or "unevenness," indicating deviations from normal anatomical development.
Characteristics: Anorectal anomalies present in various forms, classified based on the anatomical location and complexity:
- Low anomalies: The rectum ends near the perineum, often allowing for primary repair soon after birth.
- Intermediate anomalies: The rectum ends at a moderate distance from the perineum.
- High anomalies: The rectum ends far from the perineum, often connecting to the urinary tract or genital system via a fistula. These typically require a staged surgical approach, including colostomy, posterior sagittal anorectoplasty (PSARP), and eventual colostomy closure.
Common signs at birth include absence of anal opening, abnormal position of the anus, failure to pass meconium within 48 hours, or passage of stool through an abnormal orifice.
Related Topics:
- Imperforate anus
- VACTERL association
- Colostomy
- Posterior sagittal anorectoplasty (PSARP)
- Congenital malformations
- Pediatric surgery
- Neonatal screening and diagnosis