The association and embryogenesis of tracheo-oesophageal and anorectal anomalies.

Thirty-one patients with combined oesophageal and anorectal anomalies were studied. They comprised 10% of 328 consecutive foregut malformations and 246 anorectal deformities. Twenty-three of this series also exhibited at least 3 of the VATER defects. There was a very high incidence particularly of associated vertebral, urological and musculoskeletal anomalies. This high incidence of addditional lesions is presumably a reflection of generalized early damage to the mesenchymal tissues at the fourth week of gestation. Similar embryological mechanisms may take place and be affected similarly in both foregut and hindgut systems. The concept of a two-component septum dividing the foregut and hindgut is proposed to explain the formation and malformations in these regions. Disturbances of alignment, direction and extent of these component septa induced by hyperflexion of the foregut and hindgut, and intrinsic septal defects presumably account for most of the malformations. Hyperflexion may also account for malformations of other systems and for the high incidence of associated anomalies in the 31 patients with oesophagorectal deformities.