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General Surgery

Large Intestine and Anorectum Surgical Anatomy of the Colon

Built from Skandalakis' Surgical Anatomy: The Embryologic and Anatomic Basis of Modern Surgery

What’s inside

20 sections · 196 slides

  1. 01

    Overview

    • Scope of this topic
    • Anatomic and Surgical History of the Large Intestine and Anorectum
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)
    • Anatomic and Surgical History of the Large Intestine and Anorectum (continued)

    22 slides

  2. 02

    Embryology of the colon and anorectum

    • Herniation of the midgut into the umbilical cord
    • Midgut and hindgut contributions to the large intestine
    • Midgut and hindgut segments in detail
    • Partition of the cloaca into rectum and urogenital sinus
    • Timetable of anorectal development
    • Formation of the external anal sphincter
    • Development of the taeniae coli
    • Lymphoid follicles of the large intestine

    8 slides

  3. 03

    Congenital anomalies of the colon

    • Colonic stenoses and atresias
    • Distribution of intestinal atresia and stenosis
    • Hirschsprung's disease: pathogenesis
    • Distribution of aganglionic segment length
    • Line of resection in aganglionic megacolon
    • Causes of megacolon to consider in diagnosis
    • Megacolon versus massive faecal impaction

    7 slides

  4. 04

    Congenital anomalies of the anorectum

    • Classifying anorectal malformations
    • Anatomic Classification of Anorectal Malformations
    • Anatomic Classification of Anorectal Malformations (continued)
    • Classification of anorectal malformations
    • Anal (low) defects
    • Anorectal (high) defects
    • High rectal atresia
    • Rare combinations of developmental arrest, atresia and fistula
    • Embryogenesis of anal and anorectal defects
    • Germ Layer Origin of Developmental Cysts

    10 slides

  5. 05

    Topography and dimensions of the large intestine

    • Right and left colon as surgical units
    • Average lengths and diameters of the colonic segments

    2 slides

  6. 06

    Arterial supply of the colon

    • Arterial supply of the large intestine
    • Superior mesenteric artery branches to the colon
    • Collaterals of the superior mesenteric artery
    • Long and short vasa recta
    • Vasa recta and the epiploic appendages
    • Inferior mesenteric artery: origin and branches
    • Level of division of the inferior mesenteric artery
    • Variations of the arteries to the right and left colon
    • Marginal artery of Drummond
    • Quality of anastomosis at the splenic flexure
    • Terminal arterial supply and the surface features of the colon
    • Collateral flow through a dilated marginal artery
    • Critical point of Sudeck
    • Reappraisal of Sudeck's critical point

    14 slides

  7. 07

    Venous and lymphatic drainage

    • Venous drainage of the colon and rectum
    • Venous drainage of the colon
    • Venous drainage of the rectum and anus
    • Nodal groups of the large intestine
    • Lymphatic drainage of the large intestine
    • Number of Lymph Nodes in the Mesentery of the Large Intestine by Regions
    • Extent of resection for lesions in each colonic segment
    • Vascular anatomy and nodal metastasis: Yada's findings
    • Lymphatic drainage of the sigmoid colon, rectum and anus

    9 slides

  8. 08

    Innervation of the large intestine

    • Intrinsic innervation: the enteric nervous system
    • Neural control of the gut wall
    • Sympathetic innervation of the colon
    • Parasympathetic innervation of the colon

    4 slides

  9. 09

    Caecum and ileocaecal valve

    • Position and peritoneal covering of the caecum
    • Degrees of fusion of the caecum to the peritoneum
    • Types of caecal and ileal attachment to the dorsal body wall
    • Ileocaecal folds and fossae
    • Posterior relations to protect during right colon mobilisation
    • How each specialty describes the ileocaecal valve
    • Function of the ileocaecal valve
    • Branches of the ileocolic artery
    • Lymphatics of the ileocaecal region, ventral view
    • Lymphatics of the ileocaecal region, dorsal view
    • Benign Cecal Lesions

    11 slides

  10. 10

    Ascending colon

    • Fusion of the ascending colon and its variations
    • Degrees of attachment of the right colon
    • Mobile caecum
    • Conditions required for right colon volvulus
    • Percent Frequency of Persistent Right and Left Mesocolon
    • Colonic volvulus: distribution and mortality
    • Jackson's veil across the ascending colon

    7 slides

  11. 11

    Hepatic flexure, transverse colon and splenic flexure

    • Transverse colon and its mesocolon
    • Developmental relation of the transverse colon to the omentum
    • Splenic flexure: position and relations
    • Arterial supply of the transverse colon
    • Nomenclature of the colic arteries

    5 slides

  12. 12

    Descending and sigmoid colon

    • Sigmoid colon: iliac and pelvic portions
    • The lambda-shaped root of the sigmoid mesocolon
    • Sigmoid mesocolon and the left ureter

    3 slides

  13. 13

    Rectum: boundaries, peritoneum and pelvic floor

    • The surgical anal canal
    • Line of peritoneal reflection on the rectum
    • The pelvic diaphragm from below
    • Puborectalis and the anorectal ring
    • Fasciae of the pelvis in coronal section
    • The spaces of the anus and rectum
    • Ischioanal (ischiorectal) fossa
    • Pelvirectal spaces and the lateral ligaments
    • Waldeyer's fascia and the presacral space
    • Denonvilliers' fascia

    10 slides

  14. 14

    The mesorectum and total mesorectal excision

    • What the mesorectum is
    • The holy plane of rectal surgery
    • Relationships of the mesorectum in the male
    • Oncological rationale for total mesorectal excision

    4 slides

  15. 15

    Blood supply, lymphatics and spread in the rectum and anal canal

    • Arteries of the rectum and anal canal
    • Arterial supply of the rectum and anus
    • The middle rectal artery: how constant is it?
    • Lymph drainage of the anus and rectum and its two watersheds
    • The two, four, eight mnemonic
    • Routes of spread from a primary carcinoma of the colon

    6 slides

  16. 16

    Innervation of the anorectum, defecation and continence

    • Autonomic innervation of the anorectum
    • Dissection planes in front of and behind the normal rectum
    • Pelvic nerve plexus with a normal rectum and anal canal
    • Pelvic nerve plexus in anorectal agenesis with rectovesical fistula
    • Neural pathways in continence
    • Neural pathways in defecation
    • Sequence of the defecation reflex
    • Causes of faecal incontinence

    8 slides

  17. 17

    Histology of the colonic wall and rectum

    • How the colonic wall differs from the small intestinal wall
    • The five layers of the colonic wall
    • The taeniae coli
    • Appendices epiploicae
    • Valves of Houston

    5 slides

  18. 18

    The anal canal: musculature, lining and glands

    • The internal anal sphincter
    • The conjoined longitudinal coat
    • The external anal sphincter
    • The three loops of the external anal sphincter
    • Extrinsic muscles of the surgical anal canal
    • The three histologic zones of the anal canal
    • Interior of the anal canal
    • The pectinate line as a landmark
    • The Pectinate Line and Changes in the Surgical Anal Canal
    • The Pectinate Line and Changes in the Surgical Anal Canal (continued)
    • Anal glands, ducts and papillae
    • Pathogenesis of anal fistula
    • Common locations of anal abscesses and fistulous openings
    • Perianal lymphatic drainage and Goodsall's rule
    • Innervation of the anal canal and perianal skin

    15 slides

  19. 19

    Operative anatomy of the colon and anorectum

    • Abdominoperineal resection: the abdominal phase
    • Presacral bleeding
    • Nerve planes of the retrorectal space
    • Malignant Retrorectal Tumors
    • Malignant Retrorectal Tumors (continued)
    • Malignant Retrorectal Tumors (continued)
    • Standard right colectomy: four reasons to prefer it
    • Managing a short last sigmoid artery
    • Tube caecostomy
    • Tube caecostomy: indications and evidence
    • Loop colostomy
    • Loop colostomy: anatomical cautions
    • End colostomy
    • End colostomy: siting and technique
    • Laparoscopic colectomy: the case for and against
    • The colon as a reconstructive organ

    16 slides

  20. 20

    Summary and sources

    • Embryology: the points that matter
    • Vascular anatomy: the points that matter
    • Anorectal anatomy: the points that matter
    • Sources cited in the text
    • Sources cited in the text (continued)
    • Sources cited in the text (continued)
    • Sources cited in the text (continued)
    • Sources cited in the text (continued)
    • Sources cited in the text (continued)
    • Skandalakis' Surgical Anatomy: The Embryologic and Anatomic Basis of Modern Surgery
    • Join our WhatsApp groups

    11 slides