Anus

Question 1

What do haemorrhoids consist of?

Answer 1

Cluster of vascular tissue, smooth muscle and connective tissue lined by normal epithelium of the anal canal

Question 2

Risk factors for haemorrhoids

Answer 2

1) Decreased venous return (increased intra-abdominal pressure) - pregnancy, constipation + straining

2) Increased rectal vein pressure - obesity, prolonged sitting

3) Age - degeneration of collagen in connective tissue that fixes haemorrhoids to anorectal wall

Question 3

Two types of haemorrhoids

Answer 3

Internal & external haemorrhoids

Question 4

Internal haemorrhoids clinical presentation

Answer 4

Rectal bleeding, pain, mucus discharge, pruritus, prolapse

Painless, fresh bright red PR bleed after defecation - comes and goes (not like CRC which persists and progresses)

Usually painless, unless thrombosed, prolapsed w edema, strangulated

Question 5

External haemorrhoids clinical presentation

Answer 5

Usually asymptomatic

Acute local thrombosis can cause extreme pain
- rupture of vein causing tense
hematoma formation
- pt present w painful perianal
subcutaneous nodule
- pain for 2-3 days, resolves spontaneously

Question 6

Internal haemorrhoids classically present __ the pectinate line, at ___ o’clock in ___ position

Answer 6

above

3, 7, 11 o’clock in lithotomy position

Question 7

Grading for internal haemorrhoids

Answer 7

Banoy grading

Grade I: Non-prolapsing
Grade II: Prolapse on straining, spontaneous reduction
Grade III: Prolapse spontaneously/on straining, requires manual reduction
Grade IV: Chronically prolapsed, irreducible

Question 8

Grade ___ internal haemorrhoids can use non-operative ___ technique

Answer 8

II
rubber band ligation

Question 9

Where do anal fissures occur

Answer 9

Split in the anoderm (distal to the pectinate line)

Question 10

90% of anal fissures occur ____, 10% occur ___

Answer 10

posterior to anal midline
anterior

But 25% anterior in females

Question 11

Clinical presentation of anal fissure

Answer 11

Tearing pain w defecation
Anal spasm lasting for hours post defecation
Haematochezia
Pruritus/skin irritation

Question 12

Pts with acute anal fissure often unable to tolerate ___

Answer 12

DRE

Question 13

Chronic anal fissures present with

Answer 13

Hypertrophic anal papilla
Boat shaped, heaped up edges
Exposing muscle internal sphincter
Sentinal skin tag @ distal end

Question 14

What are anal fistulas?

Answer 14

Abnormal communications - hollow tracts lined w granulation tissue connecting primary opening inside anal canal to secondary opening in perineal skin.

Usually associated w anorectal abscess

Question 15

Goodsall’s rule

Answer 15

Rule for anal fistulas

Fistula opening posterior to transverse anal line: curved tract that opens into anal canal midline

Fistula opening anterior to transverse anal line: straight tract into anal canal

Question 16

Types of fistulas

Answer 16

1) Intersphincteric: internal sphincter -> intersphincteric space -> perineum

2) Trans-sphincteric: internal & external sphincters -> ischiorectal fossa -> perineum

3) Supra-sphincteric: intersphincteric space -> above puborectalis muscle -> ischiorectal fossa -> perineum

4) Extrasphincteric: perianal skin -> levator ani -> rectal wall

Question 17

Imaging for anal fistulas

Answer 17

MRI (gold standad)
Endoanal ultrasound

Question 18

What causes anorectal abscess?

Answer 18

Infection of anal glands in the anal crypts at pectinate line

Initial abscess in intersphincteric space (5%), spreads to

a) superficial to external sphincter - perianal (60%)

b) through external sphincter -> ischiorectal fossa (20%)

c) deep to external sphincter -> supra-levator space

Question 19

Clinical presentation of anorectal abscess

Answer 19

Pain (dull, throbbing) and swelling, worse on sitting & bowel movement

Fever

Erythematous, palpable swelling, fluctuant mass

Question 20

What causes anal intraepithelial neoplasia? (AIN)

Answer 20

HPV 6, 11, 16*, 18
HIV

Spread via anal intercourse

Question 21

What grade of AIN is most dangerous?

Answer 21

AIN III / high grade squamous intraepithelial lesion - 10% progresses to anal carcinoma

Question 22

Presentation of AIN

Answer 22

Pruritus, bleeding, pain, discharge

Question 23

Most anal cancers are ___ (histo)

Answer 23

squamous cell carcinomas

10% adenocarcinoma

Question 24

Risk factors for anal cancer

Answer 24

HPV 16, 18
HIV
Anal intercourse
History of genital warts

Question 25

Pattern of spread of anal cancer

Answer 25

Spreads locally upwards, outwards into anal sphincter, rectovaginal septum, perineal body, scrotum, vagina

Lymph spreads from perirectal LN, inguinal LN etc

Question 26

What is a pilonidal sinus?

Answer 26

Hair follicle in-growth with subsequent foreign body reaction around hairs of the buttock egion

Can cause abscess or carcinoma