Rectal endosonography for the visualisation of the anastomosis after anterior resection and its relevance to local recurrence.

Rectal endosonography can be used to detect and localise recurrent rectal carcinoma. Distal and proximal to a rectal anastomosis the separate layers of the bowel wall as seen by rectal endosonography are well defined but at the precise level of the anastomosis separation of the layers is lost and they appear to merge. By studying histological sections of a normal anastomosis we have demonstrated that this loss of definition seen endosonographically correlates with the histological appearances. These appearances of the normal anastomosis provide a baseline image for the identification of recurrences in the region of the anastomosis.