Anorectal and colonic anatomy

Abstract

The anatomy of the large intestine has been well described elsewhere. The emphasis of this chapter will be on the more complex and controversial aspects of the pelvic floor and the anorectum. The pelvic floor forms the supportive and caudal border of the abdominal cavity. A detailed anatomical understanding of its complex architecture is mandatory for the pelvic surgeon, who is confronted with both anorectal and urogenital dysfunctions, as different anatomical systems join here. Anatomical studies on fetal and adult specimens have demonstrated that the pelvic connective tissue can be divided into three compartments: the anterior, middle, and posterior compartment. Recent studies have highlighted the supportive function of the pelvic floor muscle systems as well as their impact on continence function and defecation. In general, sexual differences in the morphology of the muscular components already exist in early fetal stages. A thorough knowledge of the topographical relationship between the various organ systems, neurovascular structures, and connective-tissue compartments of the pelvic floor is therefore indispensable for clinical routine to improve and optimize surgical treatment for both benign and malignant conditions. © 2010 Springer-Verlag Berlin Heidelberg.