Gen Surg: Anal fistulas, abscesses, fissures and cysts Flashcards
What isa perianal fistula?
Abnormal connection between the anal canal and perianal skin
What is the relationship between anorectal abscess and perianal fistula
Around 25-40% of abcesses lead to fistular formation
What is an anorectal abscess?
Collection of pus in the anal or rectal region
Who is most affected by anorectal abscesses
20-60 y/o
Men
What are the causes of anorectal abscess?
Infection in cyrptoglandular epilithelium
Crohns
How would a patient with anorectal abscess present
Severe throbbing or stabbing pain, localised swelling, itching or discharge
fever, malaise, constipation , bleeding
What are the sites for anorectal abcesses
Supralevator
Ischiorectal
Ischiosphincteric
Perianal
What is the most common site of an anorectal abcess
Perianal
What would you find on examination of a perianal abscess
Erythematous, fluctuant, tender perianal mass.
How do you a treat a perianal abscess?
Incision and draining, either using a cruciate or elliptical incision. Then proctoscopy should be performed to check for fistula
When would you prescribe IV antibiotics for an anorectal abscess
I.v antibiotics indicated in the following situations:
Immunosuppressants
Valvular heart disease
Prosthetic devices
Sepsis or extensive cellulitis
Crohns disease
What are the risk factors for perianal fistula ?
IBD
Systemic diseases
History of trauma
Previous radiation therapy
What is a complex perianal fistula?
above or passing through the external sphincter, involving > 30%
How does a perianal fistula present?
Hx of recurrent abscess
leaking faeces
Pain
What would you see on examination of an anorectal fistula
External opening visible
Erythema
Proctoscopy–> internal opening
What is the Goodsall rule?
If the external opening is posterior to the transverse anal line, the fistula tract will follow a curved course to the posterior midline
If the external opening is anterior to the transverse anal like, the fistula tract will be in a straight line to the denate line
Where are the sites of anorectal fistula?
Extrasphincteric
Suprasphincteric
Transsphincteric
Intersphincteric
Submucosal
What sites of anorectal fistula are simple and which are complex
Simple- intersphincteric and low-lying transsphincteric, submucosal
Complex- Suprasphincteric
Extrasphincteric or high fistulas
Fistulas with multiple tracts
Recurrent fistulas
Fistulas related to IBD, infection or radiation
What is a simple anorectal fistula
minimal or no involvement of external sphincter or puborectalis
How do you treat a simple anorectal fistula?
Fistulotomy (laying it open)
How do you treat a complex anorectal fistula?
Placement of a seton through the fistula attempts to bring together and close the tract
What are the risk factors for anal fissures?
Constipation and pregnancy (particularly in 3rd trimester and delivery)
How do you manage anal fissures?
Treatment of constipation- laxatives/fibre in diet
Topical analgesics- lidocaine cream/jelly
Topical vasodilators- nifedipine or nitroglycerine
Second line treatment incl topical CCB (diltiazem)
What conditions increase risk of anal carcinoma?
HPV, Chrons, HIV
Why is opiate analgesia a RF for anal fissures?
Opiates cause constipation —> stool is hard and patient will strain —> increases the risk of tearing skin of anal canal
How do anal fissures present?
Pain on defecation - passing shards of glass. Bleed bright red on loo roll.
How des anal cancer present?
Pain, bleeding, anal discharge, pruritus, palpable mass, increasing pt age, incontience or tenesmus
What may you ask a pt about if you suspect anal cancer? (RF)
HPV infection in past - 16 and 19. Smoking. Immunosuppresision. Immunosuppressive drugs, hx of cancer, older age, many sexual partners, Chrons
Treatment of chronic anal fissure?
Topical glyceryl trinitrate
