7. Perianal Disorders Flashcards
Label A-D of the inferior anal canal.
What type of epithelium is found above and below the pectinate line?
Why are internal hemorrhoids usually painless, and external ones usually painful? State what vessels they arise from.
- *A:** pectinate/dentate line
- *B:** internal sphincter
- *C:** external sphincter
- *D:** Hilton’s white line (intersphincteric groove)
Above: columnar epithelium
Below: stratified squamous epithelium
_Internal_ = **above** pectinate line = supplied by **inferior hypogastric plexus**. Visceral sensory nerves lack pain receptors. Arise from **internal rectal plexus** _External_ = **below** pectinate line = supplied by **pudendal nerve** (from sacral plexus). Somatic innervation = painful. Arise from **external rectal plexus**
Define haemorrhoids.
What are some causes?
What are some symptoms?
Describe the pathophysiology of haemorrhoids.
Disrupted, dilated and downward displacement of normal anal cushions (spongy vascular tissue). UK prevalence 36.4%
Constipation/diarrhoea, straining, increased abdo pressure (ascites/mass), age, pregnancy, portal hypertension (decreases venous return), obesity? prolonged sitting?
PR bleeding (bright red), anal pain/discomfort, prolapse, pruritis, soiling
Result of destructive changes in supporting CT and abnormal blood circulation in anal cushions -> sliding cushions become abnormally dilated and haemorrhoidal plexus distorts (and becomes hyperperfused… - haemorrhoidal tissue contains some inflammatory cells and new microvessels)
How are haemorrhoids classified?
What are some initial non-surgical/medical treatments for haemorrhoids?
What are some parasurgical/non-operative treatments?
1st degree: remain in rectum
2nd degree: prolapse through anus on defecation but spontaneously reduce
3rd degree: 2nd degree but need digital reduction
4th degree: remain persistently prolapsed - can get strangulated
For 1st degree: Dietary manipulation (high fibre, hydration), bulking agents (fybogel), stool softeners (docusate, arachis oil, liquid paraffin), topical analgesics
For 1st & 2nd degree: rubber band ligation, injection sclerotherapy (phenol injected into pile above dentate line), infrared photocoagulation (coagulates vessels and tethers mucosa to subcutaneous tissue), cyrotherapy (e.g. anusol, high complication rate)
What are some surgical treatments for 3rd/4th degree haemorrhoids?
After any perianal surgery, what 2 things must you send the patient home on?
Conventional haemorrhoidectomy (resection - most effective. Excise piles +/- ligate vascular pedices), stapled haemorrhoidopexy (PPH) (poss. less pain and quicker return to normal), transdermal haemorrhoidal dearterialisation (THD) (US-guided ligation of haemorrhoidal artery). NB open haemorrhoidectomy: used if location of haemorrhoid makes it hard to stitch closed, or if there is a large amount of affected tissue, or if the pt is high risk for post-op infection. The incision is not stiched closed for some time to allow the wound to heal from the inside. Also can only operate on 2 haemorrhoids at a time or amt of inflammation too much. [L pic = banding, R = THD)
Laxatives and metronidazole suppository
What is an anal fissure?
What are some symptoms?
What are some causes?
Painful tear in the squamous lining of the lower anal canal.
Discharge, pain, bleeding, recurrent perianal abscess, pruritus
Overstretch of anal mucosa (most due to hard faeces), constipation, Crohn’s/UC, trauma from childbirth, rare: TB, HIV, syphilis, HPV, herpes, chlamydia
What are some non-operative treatments for anal fissures?
If these measures fail, what surgery options are available for reoccuring fissures?
Lidocaine ointment + nitroglycerin (GTN) ointment or topical diltiazem (relaxes sphincters -> fissure heals), botulinum toxin injection, nifedipine, increase dietary fibre, fluids +/- stool softener.
- *Anal stretch (Lord’s procedure)** - no longer used (incontinence SE)
- *Lateral partial internal sphincterotomy** - internal sphincter incised and partially divided to reduce spasming and improve blood supply to perianal area. Not done for females
- *Advancement flap** - reconstructive surgery
What is a fistula, and a perianal fistula?
What are some causes?
What are the 4 types of perianal fistula?
Abnormal connection between 2 epithelial surfaces.
Perianal fistula: track communicates between the skin and anal canal/rectum. Blockage of deep intramuscular gland ducts is thought to predispose to abscess formation, which discharge to form fistula
Cryptoglandular (inflammation of proctodeal glands), Crohn’s, malignancy, obstetric, radiation (pts with cervical cancer at higher risk b/c of radiotherapy), perianal sepsis, TB, diverticular disease
- *Inter** (45%)/trans (30%)/supra (20%)/extrasphincteric (5%) [pic]
- Extrasphincteric usually not associated with intersphincteric sepsis. Consider IBD/neoplasia*
How would you investigate a fistula?
What is Goodall’s rule?
What are some symptoms of a fistula?
Clinical: endoanal US; Radiological: MRI pelvis (gold std)
Determines the path of the fistula track. If external opening below transverse anal line (anterior), it’s likely to be in a straight track (radial); if above (posterior) it’s likely to be curved. Exception: if opening is >2.5cm from anal verge [Pic]
PR bleeding/discharge, perianal discharge, perianal abscess. Most come in with perianal sepsis
How are the different types of fistulas treated?
Conservative
Fistulotomy + excision: high fistulae (involving continence muscles of anus) require seton suture tightened over time to maintain continence; low fistulae are ‘laid open’ to heal by secondary intervention - division of sphincters poses no risk to continents. Risk = incontinence
Advancement flap
LIFT proceedure; ligation of intersphincteric fistula tract. Not done on NHS
Fistula plug: can contain abx
