The Colorectal Quiz Episode 4

Laparoscopic approach allows ability to biopsy elsewhere if transition zone is not rectosigmoid

Deep laparoscopic dissection into pelvis minimizes transanal work needed and avoids sphincter overstretching morbidity

Transanal dissection should take under one hour in primary pull-through

Full-thickness biopsy must include seromuscular side same size as mucosal side (cube-shaped)

Should wait for frozen section before taking mesentery

Adequate frozen section requires ganglion cells and nerves less than 40 microns

Frozen section biopsy must include submucosa to avoid missing hypertrophic nerves in submucosal layer while finding ganglion cells in seromuscular layer

Mesenteric dissection should stay close to bowel wall, not deep in mesentery, to reduce bleeding

In old Swenson procedures done through abdomen, too wide distal rectal dissection caused incontinence and urinary retention from nerve injury

Must preserve arcade along left colon and sigmoid to get enough length to reach pelvis

For distal disease, can take just distal IMA branches; for left colon disease may need to take IMA to get splenic flexure to reach

Transanal dissection should start about one centimeter above dentate line

Swenson full-thickness dissection follows areolar plane which is essentially bloodless

Soave submucosal dissection leaves a cuff; if performed, cuff should be very short (about one centimeter) and must be split

Resection margin should be approximately five centimeters above biopsy site where bowel looks good

Tacking sutures from serosa to pelvic sidewall at three and six o'clock positions anchor anastomosis in place