Colorectal Surgery

Question 1

Describe the two sphincters of the rectum

Answer 1

• Internal -> contracts at rest and principle response is to relax
• External -> stimulated during increase in intra-abdominal pressure

Question 2

Describe the type of epithelium of the rectal canal

Answer 2

From anal canal and travelling upwards: loose appendages (hair follicles, sebaceous glands) at the skin, becomes columnar epithelium

Question 3

Describe the bacteriology of normal GI tract

Answer 3

• Upper GI is sterile
• Midgut - aerobes
• Hindgut - anaerobes

Question 4

What structures does the inferior mesenteric artery (IMA) supply?

Answer 4

1/3 of distal transverse colon, splenic flexture, descending colon, sigmoid colon and rectum

Question 5

At what vertebral level does the inferior mesenteric artery (IMA) arise?

Answer 5

Branches off abdominal aorta at L3

Question 6

What is the innervation of the hindgut?

Answer 6

Nerves via the inferior mesenteric plexus

Question 7

Name the nerves which provide parasympathetic innervation to the hindgut?

Answer 7

Pelvic splanchnic nerves

Question 8

Name the nerves which provide sympathetic innervation to the hindgut?

Answer 8

Lumbar splanchnic nerves

Question 9

Give an example of a tumour of the hindgut

Answer 9

Colorectal cancer

Question 10

Give an example of inflammation of the hindgut

Answer 10

Ulcerative and Crohn’s disease

Question 11

Give an example of degeneration of the hindgut

Answer 11

Diverticular disease

Question 12

Give an example of an abnormal function of the hindugt

Answer 12

Constipation, incontinence, IBD

Question 13

Give an example of a congenital abnormality of the hindgut

Answer 13

Atresia, Hirschsprung’s disease

Question 14

What do problems with the hindgut usually present with?

Answer 14

• Change in bowel habit/continence
• Bleeding
• Pain (abdominal)
• Non-intestinal manifestations – can affect eyes, joint, skin, blood

Question 15

What is visceral pain?

Answer 15

Gut pain (visceral) poorly localised pain, but in the regions of the arterial supply of the structure, afferent nerves (in splanchnic) are conveyed along those vessels – i.e. if in location of midgut, look at the arteries that supply those structures

Question 16

Describe visceral pain

Answer 16

• Pain receptors in smooth muscle
• Afferent impulses run with sympathetic fibres accompanying segmental vessels (CP, SMA, IMA)
• Poorly localised

Question 17

What investigations are used for visualisation of the large bowel?

Answer 17

• Colonoscopy
• Flexible/ rigid sigmoidoscopy +/- barium enema
• CT colonography

Question 18

What are high risk features of presentation of colorectal cancer?

Answer 18

• Persistent change in bowel habit (>6 weeks)
• Persistent rectal bleeding without anal symptoms
• R sides abdominal mass
• Palpable rectal mass
• Unexplained iron deficiency anaemia

Question 19

What are the investigations of colorectal cancer?

Answer 19

• Endoscopy (colonoscopy and biopsy)
• Contrast imaging- barium enema
• CT/ CT colonoscopy
• MRI

Question 20

What are the treatment options for colorectal cancer?

Answer 20

• Medical vs. surgical 
• Endoscopic vs. invasive 
• Laparoscopy vs. laparotomy
• Consider:
    o	Resection 
    o	Restoration of continuity 
    o	Preservation of function 
    o	Faecal diversion

Question 21

What are the requirements for a successful bowel anastomosis?

Answer 21

• Tension free
• Well perfused
• Well oxygenated
• Clean surgical site
• Acceptable systemic state

Question 22

Name two surgeries that are guided by pathology of arterial supply

Answer 22

• Bowel anastomosis

* Faecal diversion (stoma)

Question 23

Name seven possible complications of faecal diversion (stoma) surgery

Answer 23

• Anaesthetic related
• Bleeding
• Sepsis
• VTE
• Anastomotic breakdown
• Small bowel obstruction
• Wound