RECTAL CA AND REPORTING THE ANATOMY OF IMA

Anatomy of Inferior mesenteric artery(IMA) is important while evaluating for rectal and distal sigmoid ca on cross sectional imaging

Figure: Case discussion at the end of blog

Anatomy: Branches of IMA:

1. Left colic artery

2. Sigmoid artery

3. Superior rectal artery

Anatomical variation:

1. Early origin of LCA

2. Common trunk of LCA and sigmoid artery

3. Trifurcation of LCA, sigmoid artery and the superior rectal artery

Surgeons approach during laparoscopic radical resection:

1. en-block lymph node resection at the origin of IMA

2. Tie the IMA:

- High tie at the artery at the origin. Compromises LCA supply to the

descending colon and increase risk of anastomotic leak.

- Low tie: preserves the LCA

Win-Win situation:

Early and separate branch of the LCA

Case discussion:

- 47 / M - high rectum-distal sigmoid mass

- T3

- Sphincter spared

- Tumor primarily supplied by superior rectal artery

Management Plan: Laparoscopic radical resection

Anatomical consideration: Spare the LCA as it originates separately

Further reading:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6113723/