Anatomy of the lateral ligaments of the rectum: a controversial point of view

Abstract

The existence and composition of the lateral ligaments of the rectum (LLR) are still the subjects of anatomical confusion and surgical misconception up to now. Since Miles proposed abdominoperineal excision as radical surgery for rectal cancer, the identification by "hooking them on the finger" has been accepted by many surgeons with no doubt; clamping, dividing and ligating are considered to be essential procedures in mobilization of the rectum in many surgical textbooks. But in cadaveric studies, many anatomists could not find LLR described by the textbooks, and more and more surgeons also failed to find LLR during the proctectomy according to the principle of total mesorectal excision. The anatomy of LLR has diverse descriptions in literatures. According to our clinical observations, the traditional anatomical structures of LLR do exist; LLR are constant dense connective bundles which are located in either lateral side of the lower part of the rectum, run between rectal visceral fascia and pelvic parietal fascia above the levator ani, and covered by superior fascia of pelvic diaphragm. They are pathways of blood vessels and nerve fibers toward the rectum and lymphatic vessels from the lower rectum toward the iliac lymph nodes.

Figure 1

Illustration of the anatomy of the lateral ligament of the rectum. 1: Internal iliac artery; 2: Lateral ligament of the rectum; 3: Denonvilliers’ fascia; 4: Distal part of the rectum; 5: Inter-fascial space around the distal rectum; 6: Waldeyer fascia; 7: Mesorectum; 8: Presacral fascia.

Figure 2

Operative photographs of open total mesorectal excision of rectal cancer. A: Under open surgery view, no ligament structures can be revealed in a correct surgical plane. Arrow indicates parietal pelvic fascia; B: Rectum has been removed completely. Arrow indicates rectum visceral fascia, and the rectum visceral fascia extends around the rectum, forming a continuous “hammock-like’’ sheath.

Figure 3

Operative photograph of laparoscopic total mesorectal excision of rectal cancer. 1: Left lateral ligament of the rectum; 2: Superior fascia of pelvic diaphragm; 3: Rectum visceral fascia; 4: Levator ani.