Perianal Conditions Flashcards
What are haemorrhoids?
Prolapsed vascular cushions (connective tissue and blood vessel networks) with sensory function involved in continence (bowel contents above are solid, liquid, or gas - is it safe to pass flatus?)
3 in total at 3, 7, and 11 o’clock (mucosa and submucosa)
Describe the aetiology of haemorrhoids.
Uncommon >20yrs Poor diet (low fibre, dehydrated) ---> constipation ---> straining ---> shearing forces and congestion/enlargement of vascular cushions ---> haemorrhoids bleed
What is the presentation of haemorrhoids?
- discomfort
- pruritus due to perianal discomfort + mucous discharge
- rectal bleeding = bright red, after defecation, amount varies
- prolapse during/after defecation = swelling noticed on wiping, may need to be pushed back in
What is the classification of haemorrhoids?
Internal or external
1 = bleed but do not prolapse 2 = prolapse but reduce spontaneously 3 = prolapse and require reduction 4 = prolapse and are irreducible (causing continence problems)
What is found on examination of haemorrhoids?
1st/2nd = cannot be palpated in DRE; visible on protoscope as darker blue/red mucosa bulging into end of instrument with a loss of longitudinal corrugations and three deep clefts between haemorrhoids
3rd = permanently prolapsed; mucosal covering is soft, smooth, and exudes mucus; associated with skin tags; ulcerate and bleed
Thrombosed = haemorrhoid becomes tense, hard, and oedematous —> painful defecation
note: differentiate between thrombosed haemorrhoids and perianal haematomas (covered by skin)
What investigations are appropriate in haemorrhoids?
- protoscopy
- sigmoidoscopy = exclude bowel cancer, IBD; severe symptoms e.g. severe, dark bleeding; FHx; other symptoms e.g. diarrhoea
- colonscopy if anaemia is present
What is management of haemorrhoids?
Conservative:
- diet
- increased fluid intake
- cold compress
Medical:
- creams
- stool softeners
- lignocaine
Surgical:
- banding: routine, outpatient, painless if banded above dentate line
- injection
- haemorrhoid arterial ligation operation (HALO)
- haemorrhoidectomy: painful but effective
Define fissure-in-ano.
Anal fissure. Longitudinal split (ulcer) in the skin of the anal canal.
Acute tear common in constipation (usually heals quickly)
Defecation reopens tear —> pain —> increased anal sphincter tone —> spasm —> reduced blood supply —> reduced healing —> tear more likely to reopen —> cycle of tearing, pain, and spasm —> base becomes fibrous and does not heal —> chronic ulcer of anal verge
Describe the aetiology of fissure-in-ano.
Young males and after childbirth
Common in children (pass bulky stools quickly)
What is the presentation of fissure-in-ano?
- very painful during defecation (tearing) —> chronic fissure has pain persisting for hrs —> patient afraid to defecate —> large, hard faeces —> pain worse on next defecation and harder to pass (worse spasm)
- rectal bleeding
- may be periods of remission (fissure heals or becomes chronic)
What are the examination findings in fissure-in-ano?
- majority in pos. midline (esp. males) but may be in ant. midline (female)
- small skin tag may be visible at lower end of fissure
- exquisitely tender anal sphincter
What are the appropriate investigations in fissue-in-ano?
Protoscopy/sigmoidoscopy under general anaesthesia
What is the management of fissure-in-ano?
80% improve on own
Conservative: diet, stool softeners
Medical: GTN cream, diltiazem (reduced anal tone increases blood supply), botox (temporarily relax internal anal sphincter)
Surgical: lateral sphincterotomy (contraindicated in females - shorter anal sphincter and increased risk of injury during childbirth/atrophy during menopause)
Define an ano-rectal abscess.
Infection begins in anal gland and tracks down (peri-anal abscess) or penertrates external anal sphincter (ischio-rectal abscess)
Peri-anal abscess: swelling is clearly at anal margins, which it distorts
Ischio-rectal abscess: lies lateral to anus, occupies a much larger space and can track around behind the anus to the opposite side
Abscess in intersphincteric space
Abscess in submucosa of anus
Describe the aetiology of an ano-rectal abscess.
Occur in all ages but more common at 20-50yrs
More common in males
What is the presentation of ano-rectal abscesses?
- gradual (days) onset of severe, throbbing pain which makes moving and defecation painful (worse with perianal abscesses - confined space so cannot expand)
- tender swelling close to anus
- abscess will burst if untreated
- systemic (sepsis): malaise, anorexia, sweating, rigors
What are the examination findings in ano-rectal abscesses?
- patient tries not to move and lies on their side
- tachycardia
- pyrexia/sweating
- dry, furred tongue
- fetor oris (halitosis)
- scarring from previous fistulae/abscesses
- cellulitis and necrotising fasciitis may occur
- tender red mass lateral to anus in soft tissue between anus and ischial tuberosity
- inguinal lymphn nodes may be enlarged/tender
- DRE (under anaesthesia): abscess bulges into side of lower rectum
What is the management of ano-rectal abscesses?
Anaesthetise to examine and drain
Reminder: what is a fistula?
Punctum
Pathological tract lined with epithelium/granulation tissue that connects two epithelial surfaces
Define fistula-in-ano.
Fistula connecting lumen of rectum/anal canal with external perianal skin.
Caused by abscess developing in anal crypt gland in the intersphincteric space that bursts in two directions: internally into anal canal and externally through the skin.
Mucus forced through fistulous tract as stool expelled (prevents fistula healing)
Associated with Crohn’s/UC
Can be caused by direct infiltration and necrosis of low rectal carcinoma.
What is the classification of fistula-in-ano?
LOW:
- opening below ano-rectal ring
- no significant incontinence
HIGH:
- opening above ano-rectal ring
- dividing would cause incontinence
Ano-rectal ring: puborectalis fuses with external sphincter (maintains continence)
What is the presentation of fistula-in-ano?
- Hx of perianal abscess which spontaneously burst/drained surgically
- watery/purulent/bloodstained discharge from external opening of fistula —> pruritus ani
- recurrent episodes of pain if pus collects in fistulous tract
- may appear to heal, but becomes painful and discharges again
- IBD S&S
What is Goodsall’s rule?
Internal opening of an ant. fistula lies along a radial line drawn from the external opening to the anus.
Internal opening of a pos. fistula always lies in the midline posteriorly.
What are the examination findings in fistula-in-ano?
- external opening(s) of fistula visible as puckered scar/small tuft of granulation tissue anywhere around the anus (usually close to anal verge)
- external opening of fistula not usually painful, but surrounding tissue may be thickened and tender
- DRE: internal opening of fistula may be felt as an area of induration/small nodule beneath mucosa (can determine if it is low or high) and indurated tract may be palpable under anaesthesia
