Perianal abscesses and fistulae Flashcards
What is an anal fistula?
1 - tear in anal columns of anal canal
2 - prolapse of anal column
3 - abnormal communication between anal canal and skin
4 - longitudinal tear in anal mucosa
3 - abnormal communication between anal canal and skin
- normally visualised within 2-3cm of anal margin
What is the most common cause of an anal fistula?
1 - constipation
2 - diarrhoea
3 - infection of anal glands
4 - polyps
3 - infection of anal glands
- more common in men
The most common cause of an anal fistula is an infection of anal glands. What % of patients who have a perianal abscess (pus filled collection lines by various cells) will develop an anal fistula?
1 - 0.15-0.38%
2 - 1.5-3.8%
3 - 15-38%
4 - 30-76%
3 - 15-38%
There are a myriad of causes that can lead to an anal fistula, which of the following is not a common cause of an anal fistula?
1 - crohns disease
2 - obstetric injury
3 - pelvic tumours and treatment
4 - IBD
4 - IBD
- crohns disease 15% will have one after 10 years and 20-30% after 20 years of crohns
There are lots of symptoms that can present with anal fistulas. Which of the following is NOT a typical presentation of an anal fistula?
1 - persistent anal discharge
2 - pus and/or blood discharge
3 - abdominal distension
4 - intermittent swelling and pain
3 - abdominal distension
Patients with an anal fistula can present with intermittent discharge. Which of the following does not normally present?
1 - pus
2 - mucus
3 - blood
4 - stool
4 - stool
- can be present but is not common
There are 3 classifications of anal fistulas, which are based on the how they move from the anal canal to the skin:
- intersphincteric
- transsphincteric
- extrasphincteric
In accordance with the classifications, what is goodsalls rule?
1 - site of internal opening predicts size of external opening
2 - location of internal opening predicts size of external opening
3 - location of external predicts internal opening
4 - site of external opening predicts size of internal opening
4 - site of external opening predicts size of internal opening
- anterior fistuals usually travel radially
- posterior usually arc to opening
What is the primary management of anal fistulas to reduce the risk of sepsis?
1 - drainage of fistula or abscess
2 - conservative management leaving open fistula
3 - drainage and thread into the tract
4 - suture fistula
1 - drainage of fistula or abscess
What is the best treatment for anal fistulas overall?
1 - drainage of fistula or abscess
2 - conservative management leaving open fistula
3 - drainage and thread into the tract
4 - suture fistula
2 - conservative management leaving open fistula
- 90% of fistulas will heal
- if internal or external sphincter is affected by >50%, this can cause incontinence
In patients with a high or transsphincteric (fistula crosses internal and external sphincter) fistula, what management is used if the fistula does not heal itself (which is less likely)?
1 - drainage of fistula or abscess
2 - conservative management leaving open fistula
3 - drainage and thread into the tract
4 - suture fistula
3 - drainage and thread into the tract
- multiple operations required to cure
- 60% effective
Are simple or complex fistula more common?
- simple
- a complex fistula is one that affects the sphincter, around 30% affected
What imaging technique can be used to identify the anatomy of a complex fistula prior to surgery?
1 - MRI
2 - CT
3 - ultrasound
4 - X-ray
1 - MRI
If the fistula cannot be repaired or there is a high risk of complications of the procedure (incontinence) what else can patients ask for?
1 - botox injections
2 - tissue glue to close the fistula
3 - anal canal removed and end colostomy
4 - suture close the fistula and treat with antibiotics
3 - anal canal removed and end colostomy
- similar to what happens in Crohns patients
