The Colorectal Quiz Episode 4

Laparoscopic approach allows deep pelvic dissection minimizing transanal work and avoiding sphincter overstretching

Transanal dissection in primary pull-through should take under one hour when adequate laparoscopic dissection is performed

Full-thickness biopsy should be a cube with seromuscular side matching mucosal side dimensions

Frozen section must confirm ganglion cells and nerves less than 40 microns

Frozen section biopsy must include submucosa to avoid missing hypertrophic nerves in submucosal layer

Mesenteric dissection should stay close to bowel wall to minimize bleeding and avoid injury to nerves

Historical Swenson operations done through abdomen with wide distal rectal dissection caused incontinence and urinary retention from nerve injury

Marginal arcade along left colon and sigmoid must be preserved to achieve adequate length for pelvic reach

For distal disease only distal IMA branches need division; for left colon disease IMA itself may require division

Transanal mucosal incision should be made one centimeter above dentate line

Lone Star retractor pins advance in three stages: at skin to identify dentate, covering dentate, then underneath pins at mucosal opening

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

If Soave muscular cuff is used it should be very short, approximately one centimeter, and must be split

Five-centimeter margin above biopsy site is safe for resection

Lateral tacking sutures to pelvic sidewall at three and six o'clock positions anchor the pull-through

Reinforcement layer is critical to align bowel edges for mucosa-to-mucosa anastomosis