Lateral ligaments of the rectum: an anatomical study

Abstract

Background The lateral ligaments of the rectum are surrounded by confusion and misconception. Their identification before ‘hooking them on the finger’, clamping and ligating is considered in many surgical texts to be an essential step in mobilization of the rectum. By contrast, it is the experience of many colorectal surgeons that the mesorectum can be dissected out either by diathermy or sharp dissection alone. Methods Dissection in the mesorectal plane was performed on 28 cadaveric pelves. Results In ten of the pelves, no connective tissue structure crossed from the pelvic side wall to the rectum. The remaining 18 had only very insubstantial connective tissue strands crossing this space. A total of 17 middle rectal arteries were found, all of them unilateral. Fourteen of these vessels crossed the mesorectum independent of any structure, while the remainder were part of a neurovascular bundle with a connective tissue element. Conclusion It is proposed that the ‘lateral ligaments’ of the rectum do not exist and that the term should be dropped from surgical texts. When present, the middle rectal artery is a small vessel, close to the pelvic floor. The entire rectum may be mobilized by sharp dissection without the need for clamping or ligation of any significant structure.