Video Summary

This is a demonstration of a laparoscopic, medial-to-lateral approach to mobilize the left colon. This technique can be used in any situation in which the splenic flexure would be mobilized (some surgeons selectively do so for left-sided or rectal resection). The technique involves dissection of the bloodless embryonic fusion plane between the mesocolon and the retroperitoneum and begins with dissection inferior and posterior to the IMV and continues inferiorly to the IMA before division of the splenic flexure.

Video

Teaching Points

1. Patient Preparation
   1. Preoperative bowel preparation per institutional protocol
   2. Appropriate stomal marking for diverting loop ileostomy if necessary
2. Patient Positioning
   1. Lithotomy position
   2. Arms tucked
   3. Adequately secured for appropriate positioning (Trendelenburg)
3. Critical Steps
   1. Infra-inferior mesenteric vein (IMV) dissection with medial-to-lateral dissection
   2. Entering lesser sac, dropping pancreas
   3. IMV division
   4. Infra-inferior mesenteric artery (IMA) dissection with medial-to-lateral dissection
   5. Identify and preserve the left ureter
   6. IMA division under no tension
   7. Lateral dissection/white line of Toldt
   8. Splenic flexure mobilization after entering lesser sac and freeing transverse colon
   9. Total mesorectal excision (discussed elsewhere)
4. Technical Pearls
   1. The IMV is a generally fixed landmark without aberrant anatomy, making beginning here a good first step
   2. Be careful and mind your tension with IMV to avoid avulsion
   3. Place cottonoid in lateral most dissection under splenic flexure to identify when coming laterally
   4. During IMA dissection, skeletonize if able
   5. Always identify the ureter before division of IMA
   6. Remove tension off of IMA before division
5. Potential Areas for Injury or Complications
   1. Endoscopically placed tattoo can cause tissues to become “sticky”—the tissue planes can be fused as a result of inflammation or desmoplastic reaction. This can complicate dissection of mesocolon from retroperitoneum as the planes can become distorted. This can be a result of radiation and desmoplastic reactions as well. Be comfortable with adapting procedure to pathology
   2. Beware of tension on IMV with dissection to avoid avulsion
   3. Take care to not injure the duodenum during initial IMV dissection
   4. Always identify the left ureter
   5. Be cognizant of tension of splenic flexure to avoid splenic injury or capsule tearing