Laparoscopy-assisted transanal total mesorectal excision

Subjects will have their rectal cancer removed using a technique combining surgery through the anus and standard laparoscopy. Transanal visualization will be using endoscopy. At the end of the procedure, the rectum will be removed though the anus or ileostomy formation site, the bowel will be re-connected to the anus, and a temporary diverting stoma will be created, which is standard of care following surgery for this type of cancer.

The quality of the mesorectum was determined using pathology reports and scored using three grades:

• Complete: intact mesorectum with only minor irregularities of a smooth mesorectal surface. No defect is deeper than 5 mm, and there is no coning toward the distal margin of the specimen. There is a smooth circumferential resection margin on slicing.
• Nearly complete: moderate bulk to the mesorectum, but irregularity of the mesorectal surface. Moderate coning of the specimen is allowed. At no site is the muscularis propria visible, with the exception of the insertion of the levator muscles.
• Incomplete: little bulk to mesorectum with defects down onto muscularis propria and/or very irregular circumferential resection margin.