3: Anal Lesions Flashcards
Define a haemorrhoid
Abnormal enlargement of anal vascular cushion
What is a first-degree haemorrhoid
Remains in rectum
What is a second-degree haemorrhoid
Protrudes on defecation - spontaneously reduces
What is a third-degree haemorrhoid
Protrudes on defecation - needs to be manually reduced
What is a fourth-degree haemorrhoid
Continually protruding - cannot be manually reduced
Aside from ‘degree classification’ how can haemorrhoids be categorised
Internal vs. External
Where do internal haemorrhoids arise
Superior Haemorrhoidal Plexus
What is the difference between internal and external haemorrhoids
Internal - painless
External - cutaneous pain
When is the peak incidence of haemorrhoids
45-65y
What are 5 risk factors for haemorrhoids
- Age
- Straining eg. chronic constipation
- Raised intra-abdominal pressure (pregnancy, obesity)
- FH
- Portal HTN - due to HF
How do internal haemorrhoids present
Painless
Pruritus
Bright-red bleeding
How do external haemorrhoids present
Painful mass
Pruritus
What is the most common position for haemorrhoids by ‘clock face’
3, 7 and 11 O’Clock
How are haemorrhoids investigated
DRE
What imaging may be used to confirm diagnosis of haemorrhoids
Protoscopy
How are the majority of haemorrhoids managed
conservatively
What are the 4 conservative measures for managing haemorrhoids
- Increase fibre
- Fluids
- Stool-softening laxatives
- Topical analgesia
How can first and second degree haemorrhoids be managed
Rubber band ligation
What surgical procedure is indicated for third and fourth degree haemorrhoids
Haemorrhoidectomy
What is the dentate line
A circular line comprised of anal valves. It separates upper from lower anus.
Where is the embryological origin above the dentate line
Endoderm
Where is the embryological origin below dentate line
Ectoderm
What is the cell type above the dentate line
Simple columnar
What is the cell type below the dentate line
Stratified squamous
What is blood supply above dentate line
Superior rectal artery
What is the superior rectal artery a branch of
Inferior mesenteric. a
What supplies blood to below the dentate line
Inferior rectal artery
What is the inferior rectal artery a branch of
Internal pudendal artery
Explain venous drainage above the dentate line
Internal haemorrhoid plexus Superior rectal vein Inferior mesenteric vein Splenic vein Portal vein Hepatic vein
Explain venous drainage from below the dentate line
External haemorrhoid plexus
Internal pudendal vein
Common iliac vein
What is the lymphatic drainage above the dentate line
Inferior iliac lymph nodes
What is the lymphatic drainage below the dentate line
Superficial inguinal lymph nodes
What type of muscle comprises the internal-anal sphincter
Involuntary muscle
What type of muscle comprises the external anal sphincter
Skeletal muscle
What innervates the external anal sphincter
Pudendal Nerve
When may injection sclerotherapy be used to treat haemorrhoids
Grade I or II haemorrhoids
What is injection sclerotherapy
5% Phenol is injected into haemorrhoids
What is the main complication of injection sclerotherapy
High failure rate
What are the indications for rubber band ligation of haemorrhoids
Internal haemorrhoids
What are 2 complications of rubber band ligation
Pain
Bleeding
When is a haemorrhoidectomy indicated
Grade 3 or 4 haemorrhoids
What is an anorectal abscess
Collection of pus in anal or rectal region
How do anorectal abscesses present clinically
Intermittent perianal pain - worse on sitting down
On examination how will a perianal abscess appear
Red tender mass, possibly with purulent discharge
How are peri-anal abscesses investigated
DRE under anaesthesia
How are peri-anal abscesses managed
Drainage
What is a complication of pero-anal abscesses
Peri-anal fistula
What is the most common cause of perianal abscesses
E.coli
What imaging is gold-standard for investigation of perianal abscesses
Trans perianal US
What are two risk factors for perianal abscesses
DM
Crohn’s disease
What is an anorectal fistula
Abnormal connection between anal canal and perianal skin
In which gender are anorectal fistulas more common
Males
What causes anorectal fistulas
Often secondary to perianal abscess
What are 3 risk factors for anorectal fistulas
Diabetes Crohn's disease Previous radiotherapy HIV Previous anal trauma
How do anorectal fistulas present
Continuous faecal discharge
Can cause: pain, change in bowel habit and systemic features of infection.
In what position are 90% of fistulas located
Posterior midline (6 O’ Clock position)
What imaging is used to investigate fissures in ano
Rigid sigmoidoscopy
How will an anal fissure present clinically
Intense pain post-defecation that may last for several hours
Bright red blood on defecation
What is rectal prolapse
Where a portion or all of the rectum protrudes out of the anus
What is partial thickness rectal prolapse
Where rectal mucosa protrudes out the anus
What is full-thickness rectal prolapse
Where entire rectal wall protrudes out the anus
What is an anal cancer
cancer that lies exclusively in the anal canal
What age-group does anal cancer typically occur
85-89
What causes 90% of anal cancers
HPV Infection
What strands of HPV are cancerous
HPV16 + HPV18
Give 5 risk factors for anal cancers
MSM: especially if higher number sexual partners
HIV
Women with CIN or cervical cancer
Smoking
Immunosuppressive drugs
How do anal cancers present
Pain and bleeding
What type of cancer are anal cancers mostly
Squamous cell carcinoma
What precedes development of invasive anal cancer
Anal intra-epithelial neoplasm (AIN)
What is development of AIN associated with
HPV
What investigations are performed for anorectal cancer
Protoscopy Examination under anaesthesia HIV test Cervical smear (females) US-guided FNA lymph nodes CT CAP to stage MRI to stage
What is used to manage anal cancer
Chemoradiotherapy
What is used for advanced anal cancers
Abdominoperineal resection (APR)
