Benign colorectal conditions Flashcards
Anorectal anatomy - look at pics:
How long is the rectum?
How long is the anal canal?
What type of muscle is the internal sphincter?
What type of control is used for the internal sphincter?
What nerve controls the external sphincter?
What muscle blends with the external sphincter?
15cm long
3.5cm long
Circular muscle
Parasympathetic
Pudendal nerve (S4)
Puborectalis muscle
Anorectal abscess:
What is obstructed causing the abscess?
Pathophysiology
Anal glands/crypts
6-10 structures at the dentate line of unclear function - and subsequent infection by gut bacteria
Anorectal abscess:
Most in perianal location. Where is this?
It can also be found:
- Ischiorectally
- Intersphincterically
- Supralevator
Limited to the skin of the anal canal (subcutaneous)
Crosses the external anal sphincter
Between internal and external sphincters
Superior extension above the levator ani
Anorectal abscess:
What leads to fistula formation in 50% of cases?
Rupture (spontaneous or surgical)
Anorectal abscess - risk factors:
- Bowel inflammation - 4
- Immunosuppression - 2
- Trauma - 2
- Demographic and social - 2
IBD - Crohns Diverticulitis TB Hidradentis suppurativa ---- DM HIV ------ Rectal foreign bodies Receptive anal sex ----- Male Age 20-60
Anorectal abscess - Presentation:
What would be the 2 main symptoms?
When may the symptoms be worse? - 2
What may happen as a result of the symptoms?
What may deeper abscesses cause?
Perianal pain and pruritus
Worse on sitting and defecation
Constipation due to painful defecation
Systemic illness
Anorectal abscess - Examination:
What may be found on DRE? - 2
What can be done if there is too much pain?
What imaging could be done for deeper abscesses?
Perianal swelling
Purulent/bloody discharge
Put them under general anaesthesia
Endoanal US or MRI
Anorectal abscess - Management is incision and drainage:
Where can it be done?
What is required if more complex?
Most wounds can be left open without packing. What will an intersphinteric abscess require?
What is advised after the procedure?
What can be given to help with the pain of defecation?
Ward or ED
Theatre
Post-op drain
Sitz bath (bath only to hip to clean perineum)
Laxative
Anal fistula:
What is it?
What does it most commonly happen after?
What are some other causes:
- IBD - 1
- Infection - 2
- Malignancy and Rx - 2
- Trauma -3
Abnormal communication between 2 epithelial surfaces (e.g. anal canal and the perianal skin)
Drainage or rupture of anorectal abscess
Crohns
TB, HIV
Rectal cancer or radiotherapy
Foreign body
Iatrogenic
Anal fissure
Anal fistula - classification:
Define:
- Intersphincteric - most common - 70%
- Transphincteric
- Suprasphincteric
- Extrasphincteric
The tract begins in the space between the internal and external sphincter muscles and opens very close to the anal opening.
The tract begins in the space between the internal and external sphincter muscles or in the space behind the anus. It then crosses the external sphincter and opens an inch or two outside the anal opening. These can wrap around the body in a U shape, with external openings on both sides of the anus (called a horseshoe fistula).
The tract begins in the space between the internal and external sphincter muscles and turns upward to a point above the puborectal muscle, crosses this muscle, then extends downward between the puborectal and levator ani muscle and opens an inch or two outside the anus.
The tract begins at the rectum or sigmoid colon and extends downward, passes through the levator ani muscle and opens around the anus. These fistulas are usually caused by an appendiceal abscess, diverticular abscess or Crohn’s disease.
Anal fistula - presentation - symptoms are persistent:
Main symptoms - 3
What may happen if it is left untreated? - 2
Rectal pain made worse by sittng and defecation
Discharge (continuous or intermittent) and soiling
Pruritus
Sepsis
Anatomical changes leading to incontinence
Anal fistula - most diagnosed clinically:
What imaging can be used?
Endoanal USS
MRI
Anal fistula - management:
Low fistula tract - 2 options:
- Surgery
- Injection of what?
Fistulotomy - fistula is opened by and allowed to heal by secondary intention
Injection of fibrin glue/sealant
Anal fistula - management:
High fistula tract - 4 options:
- Surgery + seton cord
- What are advancements flaps?
- What can also be put in place to stop leakage?
- What does LIFT stand for?
Fistulotomy and placement of seton cord which is left in fistula to allow drainage during the healing
Adjacent mucosa used to seal internal opening - look at pics
Fistula plug - look at pics
Ligation of intersphincteric fistula tract - look at pics
Anal fissure:
What is it?
What position are they usually found in using the lithotomy position?
Causes:
- Common cause
- Women
- Anal
- Inflammation
Longitudinal ulcer in the anal canal, anywhere from below the dentate line to the anal margin.
6’clock position - same direction as the sagittal plane
Straining constipation
Childbirth
Trauma
IBD