Perineal Abscess and fistulae

Question 1

Define Perineal abscess?

Answer 1

pus collection in the perineal region (surface region between pubic symphysis and coccyx)

Question 2

define a perineal fistula?

Answer 2

an abnormal chronically infected tract communicating between the perineal skin and either the anal canal or the rectum

Question 3

outline the aetiology of perineal absecess and fistulae?

Answer 3

Bacterial infection

Fistulae develop as a complication of an abscess

Fistulae can develop as a complications of Crohn’s disease

• The development of multiple perineal fistulae in Crohn’s disease is called pepper pot perineum

Question 4

what are the risk factors for perineal abscess and fistulae?

Answer 4

IBD

Diabetes mellitus

Malignancy

Diverticulitis

Question 5

summarise the epidemiology of perineal abscess and fistulae?

Answer 5

common

Question 6

what are the presenting symptoms of anal abscesses and fistulae?

Answer 6

constant throbbing pain in the perineum

Intermittent discharge (mucus or faecal staining) near the anal region

Personal or family history ofIBD

Question 7

what are the signs of perineal abscess and fistulae on physical examination?

Answer 7

Localised tender perineal mass (may be fluctuant)

Small skin lesion near the anus (opening of the fistula)

Painful hardened tissue felt

DRE

• A thickened area over the abscess/fistula may be felt
• DREs are not always possible due to pain and anal sphincter spasm

Goodsall’s Law

Question 8

what is Goodall’s law?

Answer 8

This is a rule that allows you to correlate the location of the internal fistula opening based on the location of the external fistula opening

If the external fistula opening is ANTERIOR to the anal canal (i.e. lies anterior to the transverse anal line), the fistula runs radially and directly into the anal canal

A fistula that is 3 cm away and any fistula that has an external fistula opening lying posterior to the transverse anal line will follow a curved path and open internally in the posterior midline

Question 9

what are investigations for perineal abscesses and fistulae?

Answer 9

Bloods

• FBC
• CRP
• ESR
• Blood culture

Imaging

• MRI– allows assessment of any fistular tracts, opening and closing of any fistulas, location of deep abscesses, damage to the anal sphincter

Endoanal Ultrasound

• Less useful than MRI

Question 10

what investigation would you consider?

Answer 10

Proctosigmoidoscopy to exclude associated diseases

Question 11

Identify possible complications of perianal abscesses and fistulae

Answer 11

Recurrence

Damage to internal anal sphincter

Incontinence

Persisting pain

Question 12

Summarise the prognosis for patients with perianal abscesses and fistulae

Answer 12

High recurrence rate without complete excision

Question 13

outline the management of abscesses?

Answer 13

surgical treatment

open drainage of abescesses

antibiotics

Question 14

what is th management of a fistula?

Answer 14

Laying Open of Fistula

• A probe is inserted to explore the fistula
• A dye can be inserted into the external opening to allow you to find the internal opening

differences between high and low fistula see other flashcard

Question 15

what is the management of a low fistula?

Answer 15

Fistulotomy

Care must be taken to prevent damage to the anal sphincter

Question 16

what is the management of a high fistula?

Answer 16

Fistulotomy would cause INCONTINENCE so is NOT performed

Seton- a non-absorbable suture that is threaded through the fistula to allow it to stay open and therefore drain

OR

Advanced flap procedure– cutting or scraping out the fistula and covering the hole where it entered the bowel with a flap of tissue taken from inside the rectum

OR

LIFT procedure– fistula sealed at both ends

OR

Endoscopic ablationton to seal the fistula

Antibiotics