Fig. 7.1
Single-incision port insertion
A bowel grasper lifts the sigmoid colon anteriorly, providing tension to the rectosigmoid mesentery. One or more “hanging stitches” of 2-0 silk suture can be placed intracorporeally to elevate the sigmoid colon to the left lateral anterior abdominal wall.
- 3.
Score the peritoneum, and then use blunt dissection to gain access to the presacral space in a medial to lateral approach .
The peritoneal reflection is scored medially. A blunt dissecting instrument and a bowel grasper are used to bluntly dissect through the areolar tissue to reach the superior presacral space (Fig. 7.2). The presacral space contains the ureter and iliac vessels laterally, so care is taken to avoid inadvertent injury to those structures.
- 4.
Dissect laterally and posteriorly along the presacral fascia on the right side of the rectum.
Fig. 7.2
Blunt dissection to reach the presacral space
Dissect laterally along the retroperitoneal fascia of the right side of the rectum using an energy source or a blunt dissecting instrument (Fig. 7.3).
- 5.
Dissect medially and posteriorly along the presacral fascia toward the left side of the rectum.
Fig. 7.3
Lateral dissection along the retroperitoneal fascia of the right side of the rectum
Dissect medially and posteriorly toward the left side of the rectum to create more space.
- 6.
Dissect superiorly to separate the retroperitoneum from the sigmoid mesentery, preserving Toldt’s fascia .
Further dissection superiorly along the presacral space will separate the retroperitoneum from the sigmoid colon mesentery. This dissection should follow the embryologic planes preserving Toldt’s fascia.
- 7.
Identify the left ureter and avoid the iliac vessels within the lateral presacral space.
At this point, the left ureter lies within the dissection field. Take care to identify the left ureter at this point to prevent accidental ligation (Fig. 7.4).
- 8.
Score the peritoneum proximal and distal to the IMA, and dissect until origin of the left colic artery is seen.
Fig. 7.4
Identify the left ureter to avoid injury
The peritoneum proximal and distal to the inferior mesenteric artery is then scored, and dissection continues until the inferior mesenteric artery and left colic artery are seen. Triangulation is used with blunt instruments, sweeping the retroperitoneum down and opening up the plane.
- 9.
Optional: Selective lymph node dissection surrounding the root of the inferior mesenteric artery.
At this time, a selective lymph node dissection surrounding the IMA root at the aorta can be completed if the surgeon so desires. The surgeon must identify and avoid injuring the inferior mesenteric plexus at this point.
- 10.
Ligation of the inferior mesenteric artery (IMA).
The IMA is then ligated using a laparoscopic energy device, vessel sealer, or clip, either above or below the branching of the left colic artery [24]. For high ligation, we recommend ligating the IMA within 2 cm of its origin to the aorta. The IMV is ligated in a similar manner near the inferior margin of the pancreas. For low ligation, ligate the IMA distal to the origin of the left colic artery using either clips, a bipolar vessel sealer, harmonic scalpel, or a stapler. The apical lymph node tissue is not taken, but blood flow to the left colic artery is maintained (Fig. 7.5).
Fig. 7.5
High IMA ligation
The surgeon may choose to ligate and divide the IMA at another location that is distal to the left colic artery branch (Fig. 7.6). Some authors have even differentiated the ligations that preserve the origin of the left colic artery by coining the terms “mid” and “low” ligation based on distance from the edge of the colon [21]. If additional length is not required in creating the anastomosis and if the surgery is for a benign disease when lymph node collection is irrelevant, then the lower ligations can preserve essential blood flow to the anastomosis. One option for the low ligation is at the level of the superior rectal artery, leaving some sigmoidal arteries intact. This is a useful modification for a proctectomy for benign disease. Splenic flexure mobilization may be needed to gain enough proximal length to create the anastomosis without tension. A more proximal IMA ligation may still be warranted for this technical reason if after mobilization more length is still required [29].
- 11.
Proceed with colorectal resection and anastomosis creation following the vessel ligation .
Fig. 7.6
Low IMA ligation, distal to the left colic artery
Summary
Inferior mesenteric artery ligation can occur flush to the aorta, proximal to the left colic artery, or at several locations distal to the branching of the left colic artery. In single-incision laparoscopic surgery, as in traditional open or laparoscopic surgery, the decision surrounding the level of IMA ligation is informed by operative indication, technical limitations, and anatomic considerations. Though a high IMA ligation is generally performed in oncologic cases, the research demonstrating its overall mortality benefit is mixed when compared to low ligation. A randomized, controlled trial is ongoing to examine patient outcomes following a high IMA ligation versus a low ligation in low anterior resections. The use of a high IMA ligation can remove undue tension on the anastomosis, and a high IMA ligation might be therefore useful in surgical resections for benign pathology. The competent surgeon needs to understand the additional risks of a high IMA ligation and the proper operative techniques to minimize the inadvertent injury of vascular, urinary, and nervous system structures. Maintaining adequate perfusion to the anastomosis is key to prevent postoperative complications, and the development and use of new perfusion imaging technology may prove beneficial.
References
1.
Keighley MRB, Williams NS, Church JM, Pahlman L, Scholefield JH, Scott NA. Anatomy and physiology investigations. In: Keighley MRB, Williams NS, Church JM, Pahlman L, Scholefield JH, Scott NA, editors. Surgery of the anus, rectum, and colon. 3rd ed. London: Elsevier; 2008. p. 1–45.
2.
Griffiths JD. Surgical anatomy of the blood supply of the distal colon. Ann R Coll Surg Engl. 1956;19(4):241–56.PubMedPubMedCentral
3.
Drummond H. Some points relating to the surgical anatomy of the arterial supply of the large intestine. Proc R Soc Med. 1914;7(Surg Sect):185–93.PubMedPubMedCentral
4.
5.
Steward JA, Rankin FW. Blood supply of the large intestine: its surgical considerations. Arch Surg. 1933;26(5):843–91.Crossref
6.
Morgan CN, Griffiths JD. High ligation of the inferior mesenteric artery during operations for carcinoma of the distal colon and rectum. Surg Gynecol Obstet. 1959;108(6):641–50.PubMed
7.
8.
Alici A, Kement M, Gezen C, Akin T, Vural S, Okkabaz N, et al. Apical lymph nodes at the root of the inferior mesenteric artery in distal colorectal cancer: an analysis of the risk of tumor involvement and the impact of high ligation on anastomotic integrity. Tech Coloproctol. 2010;14(1):1–8.CrossrefPubMed
9.
10.
11.
12.
Lange MM, Buunen M, van de Velde CJ, Lange JF. Level of arterial ligation in rectal cancer surgery: low tie preferred over high tie. A review Dis Colon Rectum. 2008;51(7):1139–45.CrossrefPubMed
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
