Detailed and applied anatomy for improved rectal cancer treatment

Abstract

Rectal anatomy is one of the most challenging concepts of visceral anatomy, even though currently there are more than 23,000 papers indexed in PubMed regarding this topic. Nonetheless, even though there is a plethora of information meant to assist clinicians to achieve a better practice, there is no universal understanding of its complexity. This in turn increases the morbidity rates due to iatrogenic causes, as mistakes that could be avoided are repeated. For this reason, this review attempts to gather current knowledge regarding the detailed anatomy of the rectum and to organize and present it in a manner that focuses on its clinical implications, not only for the colorectal surgeon, but most importantly for all colorectal cancer-related specialties.

Keywords: Anatomy; cancer; rectum; surgery.

Figure 1

(A) The “sigmoid take off” shown on a sagittal T2-w magnetic resonance (MR) image (arrow). (B) The “seagull” sign on an axial T2-w MR image (arrow). (C) Douglas pouch in a woman, on sagittal T2-w MR image (arrow)

Figure 2

(A) Median sagittal plane in a male cadaveric right hemipelvis. The yellow band indicates the prostatic part of the urethra. AMF, anterior mesorectal fascia; ARW, anterior rectal wall; DVF, Denonvillier’s fascia; NF, penetrating rectal nerve fibers; SV seminal vesicles. With permission of Institute of Anatomy, University of Kiel, Germany. (B) Median sagittal plane in a male cadaveric right hemipelvis. Red loop indicates the superior rectal artery (SRA); blue loop indicates the superior rectal vein (SRV). RSL, rectosacral ligament; MR, mesorectum; PSF, presacral fascia; PPF parietal pelvic fascia; S3, S4, S5, sacral vertebrae 3, 4, 5; CC, coccyx. With permission of Institute of Anatomy, University of Kiel, Germany. S, superior; A, anterior; P, posterior; I, inferior.

Figure 3

(A) Median sagittal plane in a male cadaveric right hemipelvis. Red loop indicates the right lateral rectal ligament (LRL); RHN indicates the right hypogastric nerve embedded into the parietal pelvic fascia (PPF). With permission of Institute of Anatomy, University of Kiel, Germany. (B) Median sagittal plane in a male cadaveric right hemipelvis. Red loop indicates a middle rectal artery (MRA) arising from the internal iliac artery (IIA); blue loop indicates a middle rectal vein (MRV) draining to the internal iliac vein (IIV); green square indicates an internal iliac lymph node (LN). S1, S2, S3, S4, S5, sacral vertebrae 1, 2, 3, 4, 5. With permission of Institute of Anatomy, University of Kiel, Germany. S, superior; A, anterior; P, posterior; I, inferior.

Figure 4

Median sagittal plane in a male cadaveric right hemipelvis. The upper yellow loop indicates the right hypogastric nerve (RHN); UB indicates the branch from the hypogastric nerve for the ureter; the lower yellow loop indicates the sacral (splanchnic) nerves (SSN); the yellow strip indicates the T-junction (TJ); SVF indicates the nerve fibers from the inferior hypogastric plexus radiating towards the seminal vesicles; IASN indicates the nerve fibers for the internal anal sphincter; dagger (†) indicates the hypogastric nerve fibers for the vas deferens, the seminal vesicles and the urinary bladder. DVF, Denonvillier’s fascia; MR mesorectum; S1, S2, S3, S4, S5, sacral vertebrae 1, 2, 3, 4, 5. With permission of Institute of Anatomy, University of Kiel, Germany. S, superior; A, anterior; P, posterior; I, inferior.