Anal fissure

Question 1

What is an anal fissure?

Answer 1

An anal fissure is a longitudinal and superficial tear of the epithelium and dermis at the anal margin extending up into the anal canal but below the dentate line.

Question 2

anatomically, where do anal fissures develop?

Answer 2

In the posterior aspect of the anal canal

Question 3

Who are the at-risk groups for anal fissures?

Answer 3

1. Post-partum women
2. Elderly

Question 4

How prevalent are anal fissures?

Answer 4

Anal fissures affect 1 in 350 people each year and can affect any age

Question 5

What is the most common risk factor for an anal fissure?

Answer 5

Constipation

Question 6

What are the mechanical risk factors of anal fissures?

Answer 6

due to the passage of a hard and bulky stool at the origin of an endodermal tear

Question 7

How does hypertonia of the internal anal sphincter increase risk of anal fissures?

Answer 7

is thought to reduce the blood supply to the anus and thus slows down the healing process

Question 8

How is ischaemia a risk factor for an anal fissure?

Answer 8

Hinders the healing process of the fissure

Question 9

What is the list of risk factors for anal fissures?

Answer 9

Constipation
Low fibre diet
Inflammatory bowel disease (IBD)
Chronic diarrhoea
Pregnancy
Opioid analgesia: due to constipation

Question 10

Give two presentations associated with anal fissures:

Answer 10

1) sharp pain of defaecation often followed by a deep burning pain that may last several hours
2) bleeding into faeces

Question 11

How are anal fissures diagnosed? (2)

Answer 11

1) history
2) perianal inspection

Question 12

True or false: digital rectal examinations are a recommended investigation for anal fissures

Answer 12

false (it can worsen the fissure and cause sphincter spasm)

Question 13

Give two investigations used for severe anal fissures to exclude any other anorectal disease:

Answer 13

1) proctoscopy
2) sigmoidoscopy

Question 14

What is a proctoscopy?

Answer 14

visual examination of the rectum using a scope

Question 15

What are the clinical findings of anal fissures?

Answer 15

Fissures can be palpable or visible around the anus
A tear can be seen on the posterior aspect

Question 16

What are the differential diagnoses of anal fissures?

Answer 16

Thrombosed haemorrhoids: which present with anal pain and bright red rectal bleeding seen internally with a proctoscope

Inflammatory bowel disease: presents with more chronic symptoms and other extra-intestinal features such as episcleritis and erythema nodosum

Sarcoidosis

Malignancy: anal carcinoma presents with red flag symptoms (change in bowel movements, weight loss, family history) and may require an examination under anaesthesia with biopsy

Peri-anal abscess: presents with purulent discharge and anal pain. It appears as a pus-filled swelling rather than a tear in the skin.

Question 17

Give 3 treatments used for anal sphincters:

Answer 17

1) local anaesthetic gel
2) stool softeners/ laxatives
3) glyceryl trinitrate and diltiazem ointments (relax sphincters)

Question 18

Name two drugs that can relax anal sphincters and therefore permit healing of anal sphincters:

Answer 18

1) glyceryl trinitrate
2) diltiazem ointments

Question 19

Name the surgical intervention for very severe anal fissures:

Answer 19

lateral subcutaneous internal sphincterotomy

Question 20

Describe how a lateral subcutaneous internal sphincterotomy helps treat severe anal fissures:

Answer 20

the anal sphincter is divided in order to reduce spasming and thus improve blood supply to the perianal area - this increased blood supply and aids healing

Question 21

What is the dentate/pectinate line?

Answer 21

line which divides the upper two thirds and lower third of the anal canal

Question 22

What is a fissurectomy?

Answer 22

an alternative involving resection of fibrous edges of the fissure. It can also be completed with anoplasty.

Question 23

What are the 2 main complications of anal fissures?

Answer 23

1. Faecal incontinence after surgery
2. Reccurence