'Isolated' Appendix - An Unusual Presentation

Appendix is blind muscular tube with all layers of intestine. Morphologically it is the underdeveloped end of Caecum and is considered as a vestigial organ. It arises as a diverticulum from the post-arterial segment of the midgut loop. The caecum and the appendix are formed by enlargement of this bud. But due to differential growth of the walls of this bud, the lateral (right) wall growing more rapidly than the medial (left) wall causes the point of attachment of the appendix to lie on the medial side of caecum, resulting in a tubular structure of varying length from 6 to 9 cm. rotation of the appendix commonly results in a retroperitoneal but intraabdomoinal structure. In approximately one quarter of the cases, rotation of the appendix is incomplete resulting in pelvic, subcaecal or paracaecal position. Mesoappendix arises from lower surface of the mesentery of terminal ileum and contains appendicular artery at its free end. Occasionally accessory artery may be present.