Anatomy - Rectal resection, robot-assisted with total mesorectal excision (TME)

The following parts of the intestine are relevant during the operation:

• Descending colon:
  • Location: secondary retroperitoneal
  • Peritoneal suspension: fused with the posterior wall of the abdominal cavity
  • Course: from the left flexure (here: phrenocolic ligament with fixation to the spleen) to the iliac fossa, connects to the transverse colon and transitions into the sigmoid colon
  • Length: 20-30 cm
• Sigmoid:
  • Location: intraperitoneal
  • Peritoneal suspension: sigmoid mesocolon
  • Course: from the iliac fossa as a loop (S-shaped) to the level of the 2nd-3rd sacral vertebra, connects to the descending colon and transitions into the rectum
  • Length: variable (elongated sigmoid), usually about 35 cm
• Rectum:
  • Transition from sigmoid colon to rectum before the 2nd-3rd sacral vertebra.
  • Length 16 cm
  • Division into thirds: The height of the margins is measured with a rigid endoscope, using the anal-cutaneous line as a reference.
    • Lower third 0-6cm
    • Middle third 6-12cm
    • Upper third 12-16cm
    • each measured from the anal-cutaneous line

• Fascia pelvis parietalis covers the pelvic wall with vessels, vegetative nerves, and presacral venous/nerve plexus.
• Above the anorectal junction, the fascia rectosacralis meets the fascia pelvis visceralis.
• The visceral fascia includes the fascia propria organi pelvis (surrounding the mesorectum dorsally and laterally) and the ventrally located Denonvilliers fascia.
• The Denonvilliers fascia lines the posterior wall of the bladder, the seminal vesicles, and the posterior wall of the prostate in men.