ANAL ENDOSONOGRAPHY AND CORRELATION WITH INVITRO AND INVIVO ANATOMY

The endosonographic anatomy of the anal sphincters was studied by in v ivo and in vitro correlation with anatomical dissection. Fourteen fres h anorectal specimens (eight abdominoperineal resection, six post mort em) were scanned in a water-bath with sequential dissection and correl ation with the ultrasonographic images. Accurate anatomical identifica tion of the layers during dissection was confirmed histologically. Ana l endosonography was performed during operation in 12 patients to vali date the in vitro findings. The in vivo study confirmed the in vitro r esults. Basic endosonographic anatomy has been clarified and inaccurac ies in the previous description of the longitudinal muscle and externa l anal sphincter corrected.