Perianal Surgery Flashcards
What is the anatomy of the rectum?
- 12cm
- Sacral promontory to levator ani muscles
- The 3 tenia coli fuse around the rectum to form a
continuous muscle layer
What is the anatomy of the anal canal?
- 4cm
- Levator ani muscle to anal verge
- Upper 2/3 of canal
Lined by columnar epithelium
Insensate
Superior rectal artery and veni
Internal iliac nodes
- Lower 1/3 canal Lined by squamous epithelium Sensate Middle and inf rectal arteries and veins Superficial inguinal nodes
Dentate line = squamomucosal junction
White line = where anal canal becomes true skin.
What are the anal sphincters
Internal - thickening of rectal smooth muscle. Involuntary control.
External: Three rings of skeletal muscle
- Deep
- Superficial
- Subcut
Under voluntary control
- Anorectal ring - Deep segment of external sphincter which is continuous with puboretalis muscle (part of levator ani)
- Palpable on PR ~5cm from the anus
- Demarcates junction between anal canal and rectum
- Must be preserved to maintain continence.
What is a perianal haematoma?
Subcut bleeding from a burst venule caused by straining or the passage of hard stool
Also called an external pile.
Presents
- tender blue lump at the anal margin
- Pain worsened by defecation or movement
Management
- Analgesia + Spontaneous resolution
- Evacuation under LA
What is proctalgia fugax?
Young, anxious man
Crampy anorectal pain worse @ night.
Unrelated to defection
Associated with trigeminal neuralgia
Reassurance
GTN cream
Perineal warts?
SEen in MSM
Condylomata accuminata
- HPV
- Manage: podophyllin pain, cryo, surgical excision
- Condylomata lata
Syphilis - Manage: penicillin
What is pruritis ani caused by?
50% idiopathic Poor hygiene Haemorrhoid Anal fissure Anal fistula Fungi, worms Crohns Neoplasia
What are haemorrhoids?
Disrupted and dilated anal cushions
Pathophysiology
- Anal cushion: mass of spongy vascular tissue
- Positioned @ 3, 7, 11 O-clock.
Where the three major arteries that feed the vascular plexuses enter the anal canal.
Gravity, straining –> engorgement and enlargement of anal cushions.
Hard stool disrupts connective tissue around cushions
- Cushions protrude and can be damaged by hard stool
- -> bright red (capillary bleeding)
- Haemorrhoid arise above dentate line so not painful.
May ulcerate if gripped by anal sphincter.
Causes of haemorrhoids?
Constipation with prolonged straining Venous congestion may contribute - Pregnancy - Abdominal tumour - Portal HTN
Classifications of haemorrhoids?
1st degree: never prolapsed
2nd degree: prolapse on defection but spontaneously reduce
3rd: prolapse on defecation but require digital reduction
4th: remain permanently prolapsed.
Symptoms of haemorrhoids?
Fresh painles PR bleeding
- Bright red
- On paper, on stool, may drip into pan
- Pruritis ani
- Lump in perianal area
- Severe pain = thrombosis
Examination of haemorrhoids?
- Full abdo exam, palpating for masses
- Inspect perianal area: masses, rectal bleeding
- DRE: can’t palpate piles unless thrombosed
rigid sig to identify higher rectal pathology - Proctoscopy (also allows Rx)
Differential for haemorrhoids?
Perianal haematoma
Fissure
Abscess
Tumour
Management of haemorrhoids?
Conservative
- Increased fibre and fluid intake
- Stop straining at stool
Medical management of haemorrhoids?
Topical preparations
- Anusol: hydrocortisone
- topical analgesics
Laxatives: lactulose, Fybogel
Intervention of haemorrhoids?
Injection with sclerosant 0 5% phenol in Almond oil
- above dentate line. Can cause impotence and prostatitis.
Barron’s banding –> thrombosis and separation. Superior to injection sclerotherapy.
- SE: bleeding, infection
Cryotherapy
- SE: watery discharge post-procedure
Infra-red coagulation
What are the surgical options for haemorrhoids?
- Excision of piles + ligation of vascular pedicles
- Lactulose + metronidazole 11 week pre-op
- Discharge with laxatives post-op
- SE: bleeding, stenosis.
How do you manage thrombosed piles?
Significant pain, examination reveals a purplish oedematous, tender subcut perianal mass.
If patient presents within 72hrs then referral should be considered for excision.
- Analgesia
- Ice-packs
- Stool softener
- Bed rest with elevated foot of bed
- Pain usually resolves in 2-3 weeks
- Haemorrhoidectomy is not usually necessary.
What is an anal fissure?
Tear of squamous epithelial lining in lower anal canal
Causes of anal fissure?
Mostly trauma 2ndry to passage of hard stool
- associated with constipation
- Spasm of internal anal sphincter contributes to pain and –> ischaemia + poor healing.
- Commoner in women
Rare causes of anal tissue?
Multiple + lateral fissures
- Crohns
- Herpes
Anal Ca
Presentation of anal fissure?
Intense anal pain
- Especially on defecation
- may prevent pt from passing stools
- Fresh rectal bleeding
On paper mostly.
Examination of anal fissure?
PR often impossible
Midline ulcer is seen
- Usually posterior @ 6 O’clock
- may be anterior
May be mucosal tag –> Sentinel pile (usually posterior @ 6 oclock)
Groin LNs suggest complicating factor: e.g HIV.
Management of anal fissure?
If fissure recurrent, chronic or difficult to manage the patient required EUA.