The perirectal fascia: morphology and use in staging of rectal carcinoma.

A revised anatomy of the perirectal fascia is proposed based on more than 2,000 CT examinations of the lower pelvis. CT examination showed that the perirectal fascia completely encloses the "capsula adipose rectalis" within the subperitoneal space and separates the perirectal compartment from the "pararectal connective tissue." The accuracy of CT in preoperative staging of rectal carcinoma was also demonstrated. It is concluded on the basis of 155 preoperative CT examinations of rectal carcinoma that CT staging is superior to Mason's clinical staging scheme, although routine staging by CT is not justified because slight perirectal tumor spread and lymph node metastasis cannot be predicted accurately.