Anorectal Disease Flashcards
What’s anal fissure?
Definition of acute and chronic anal fissure
Anal fissures are tears of the squamous lining of the distal anal canal.
- if present for less than 6 weeks → ACUTE
- if present for more than 6 weeks → CHRONIC
(3) risk factors for anal fissures
- constipation
- inflammatory bowel disease
- sexually transmitted infections e.g. HIV, syphilis, herpes
Causes of anal fissure
- trauma secondary to the passage of hard stool
- associated with constipation
- spasm of internal anal sphincter contributes to pain and → ischaemia + poor healing
- Commoner in women
• Rarer causes:
- Crohn’s
- 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 due to pain
Inspection
• Midline ulcer is seen
- Usually posterior @ 6 O’clock
- May be anterior
• May be a mucosal tag – sentinel pile
-usually posterior @ 6 O’clock
• Groin LNs suggest complicating factor: e.g. HIV
Management of acute anal fissure
Management of an acute anal fissure (< 6 weeks)
- dietary advice: high-fibre diet with high fluid intake
- bulk-forming laxatives are first-line - if not tolerated then lactulose should be tried
- lubricants such as petroleum jelly may be tried before defecation
- topical anaesthetics e.g. lignocaine
- analgesia
Management of chronic anal fissure
Management of a chronic anal fissure (> 6 weeks)
- the above techniques should be continued
- topical glyceryl trinitrate (GTN) is first-line treatment for a chronic anal fissure
- if topical GTN is not effective after 8 weeks then secondary care referral should be considered for surgery or botulinum toxin
What’s fistula in ano?
Abnormal connection between ano-rectal canal and
the skin
Pathophysiology of anal fistula
- Blockage of intramuscular glands → abscess → abscess discharges to form a fistula
Conditions associated with anal fistula
- Crohn’s
- Diverticular disease
- Rectal Ca
- Immunosuppression
Classification of fistula in ano (2)
- High: cross sphincter muscles above dentate line
- Low: cross sphincter muscles below dentate line
What’s Goodshall’s role?
Goodsall’s Rule → determines path of fistula tract
- Fistula anterior to anus track in a straight line (radial)
- Fistula posterior to anus always have internal opening at the 6 o’clock position → curved track
Presentation of fistula in ano (2)
- Persistent anal discharge
- Perianal pain or discomfort
Findings on examination of fistula in ano
- May visualise external opening: may be pus
- Induration around the fistula on DRE
- Proctosopy may reveal internal opening
Ix for fistula in ano (2)
- MRI
- Endoanal US
Management of:
- low fistula
- high fistula
Extent of fistula must first be delineated (visualised) by probing the fistula during examination under anaesthetic
Low Fistula
- Fistulotomy and excision
- Laid open to heal
High Fistula
• Fistulotomy could damage the anorectal ring
• Suture – a seton – passed through fistula and
gradually tightened over months
-Stimulates fibrosis of tract
-Scar tissue holds sphincter together
Upper 2/3 of the anal canal
- what epithelium
- sensation
- what artery and vein
- what lymph nodes
Upper 2/3 of canal
- Lined by columnar epithelium
- Insensate
- Superior rectal artery and vein
- Internal iliac nodes
Lower 1/3 of the anal canal
- epithelium
- sensation
- artery and veins
- lymph nodes
Lower 1/3 of canal
- Lined by squamous epithelium
- Sensate
- Middle and inf. rectal arteries and veins
- Superficial inguinal nodes
What are:
- dentate line
- white line
- Dentate line = squamomucosal junction
- White line = where anal canal becomes true skin
What are (3) anal sphincters?
- Internal anal sphincter
- External anal sphincter
- Anorectal ring
Anal sphincters:
A. Internal:
- role and control
B. External: structure and control
Internal
- Thickening of rectal smooth muscle
- Involuntary control
External
- Three rings of skeletal muscle (Deep, superficial, subcutaneous)
- Voluntary control
What’s perianal haematoma?
- Subcutaneous bleeding from a burst venule → caused by straining or the passage of hard stool
- Also called an external pile
Presentation of Perianal haematoma
- Tender blue lump at the anal margin
- Pain worsened by defecation or movement
Management of perianal haematoma (2)
- Analgesia + spontaneous resolution
- Evacuation under LA
Proctalgia fugax
- common group of patients
- what is this
- associated with which condition
Group: Young, anxious men
Proctalgia fugax: Crampy anorectal pain, worse @ night
• Unrelated to defecation
Association: trigeminal neuralgia
Management of proctalgia fugax
- Reassurance
- GTN cream
Perianal warts
- common group of patients
Perianal warts
homosexual men (men who have sex with men)
Types (2) of perianal warts and what’s the difference + treatment?
Perianal warts
A. Condylomata accuminata
• HPV
• Rx: podophyllin paint, cryo, surgical excision
B. Condylomata lata
•Syphilis
• Rx: penicillin
What are haemorrhoids?
- Haemorrhoidal tissue → part of the normal anatomy; contributes to anal continence
- They are mucosal vascular cushions
- found in the left lateral, right posterior and right anterior portions of the anal canal (3 o’clock, 7’o’clock and 11 o’clock respectively)
- Haemorrhoids are said to exist when they become enlarged, congested and symptomatic
Clinical features of haemorrhoids
- painless rectal bleeding is the most common symptom
- pruritus
- pain: usually not significant unless piles are thrombosed
- soiling may occur with third or forth degree piles
Pathophysiology of haemorrhoids
- 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.
Two types of haemorrhoids and what’s the difference
External
- originate below the dentate line
- prone to thrombosis, may be painful
Internal
- originate above the dentate line
- do not generally cause pain
Classification of haemorrhoids
What contributes to the development of haemorrhoids (causes)
Constipation with prolonged straining
• Venous congestion may contribute
- Pregnancy
- Abdominal tumour
- Portal HTN
Examination of haemorrhoids
- full abdo exam → palpating for masses
- Inspect perianal area: masses, recent bleeding
- DRE: can’t palpate piles unless thrombosed
- Rigid sigmoidoscopy → to identify higher rectal
Conservative and medical management of haemorrhoids
Conservative
- ↑ fibre and fluid intake
- Stop straining @ stool
Medical
- Topical preparations
- Anusol: hydrocortisone
- Topical analgesics
- Laxatives: lactulose, fybogel
Interventional management for haemorrhoids (4) and its SEs
Interventional
A. Injection with sclerosant (5% phenol in Almond oil)
- Injection above dentate line
- SE: impotence, prostatitis
B. Banding → thrombosis and separation
-SE: bleeding, infection
C. Cryotherapy
-SE: watery discharge post-procedure
D. Infra-red coagulation
Surgical intervention for haemorrhoids (1)
- name
- discharge prescription
- SEs
Haemorrhoidectomy
- Excision of piles + ligation of vascular pedicles
- Discharge with laxatives post-op
- SE: bleeding, stenosis
Management of Acutely thrombosed external haemorrhoids
Acutely thrombosed external haemorrhoids
- if patient presents within 72 hours then referral should be considered for excision
- Otherwise patients can usually be managed with stool softeners, ice packs and analgesia (topical lignocaine jelly)
- Symptoms usually settle within 10 days
Presentation of acutely thrombosed external haemorrhoids
- typically present with significant pain
- examination reveals a purplish, oedematous, tender subcutaneous perianal mass
Pathogenesis of Perianal sepsis/abscess
- Anal gland blockage → infection ( e.g. E.coli) → abscess
- May develop from skin infections
- E.g. sebaceous gland or hair follicle
- Staphs
(3) conditions associated with the development of anal abscesses
- Crohn’s
- DM
- Malignancy
Classification and symptoms of anal abscess (4)
- Perianal: 45%
- discrete local red swelling close to the anal verge
- Ischiorectal: ≤30%
- systemic upset
- Extremely painful on DRE
- Interphincteric / intermuscular: >20%
- Pelvirectal / supralevator: ~5%
- Systemic upset
- Bladder irritation
Presentation of anal abscess
- Throbbing perianal pain → worse on sitting
- Occasionally a purulent anal discharge
Examination of anal abscess
- Perianal mass or cellulitic area
- Fluctuant mass on PR
- Septic signs: fever, tachycardia
Management of anal abscess
- antibiotics
Most cases require examination under anaesthesia with incision and drainage
- Wound packed
- Heals by secondary intention
- Daily dressing for 7-10 days
* Look for an anal fistula which complicates ~30% of
abscesses
What’s Pilonidal Sinus?
- Pilonidal: latin → “nest of hair”
- Sinus: blind ending tract, lined by epithelial or
granulation tissue, which opens onto an epithelial
surface
Pathophysiology of Pilonidal sinus
- Hair works its way beneath skin → foreign body reaction → formation of abscess
- Usually occur in the natal cleft
Risk factors for Pilonidal abscess
- M>F=4:1
- Geo: Mediterranean, Middle east, Asians
- Often overweight with poor personal hygiene
- Occupations with lots of sitting: e.g. truck drivers
Presentation of pilonidal abscess
- Persistent discharge of purulent or clear fluid
- Recurrent pain
- Abscesses
Management of pilonidal abscess
Conservative
- Hygiene advice
- Shave / remove hair from affected area
Surgical
- Incision and drainage of abscesses
- Elective sinus excision
- Methylene blue to outline tract
- Recurrence in 4-15%
Types of anal cancers
- 80% SCCs
Other:
- melanomas
- adenocarcinomas
Anal margin tumours
- type
- prognosis
Anal margin tumours
- Well differentiated keratinising lesions
- Commoner in men
- Good prognosis
Anal canal tumours
- origin
- type
- prognosis
Anal canal tumours
- Arise above dentate line
- Poorly differentiated, non-keratinising
- Commoner in women
- Worse prognosis
Spread of anal carcinoma (2)
- Above dentate line → internal iliac nodes
- Below dentate line → inguinal nodes
Conditions associated with anal carcinoma
- HPV (16, 18, 31, 33) is important factor
- ↑ incidence in men who have sex with men
- ↑ incidence if perianal warts
Possible presentations of anal cancer
- Perianal pain and bleeding
- Pruritis ani
- Faecal incontinence
- 70% have sphincter involvement @
presentation
- possible → rectovaginal fistula
Clinical examination of anal cancer
- Palpable lesion in only 25%
- ± palpable inguinal nodes
Investigations of anal cancer
↓• Hb (ACD)
- Endoanal US
- Rectal EUA + biopsy
- CT / MRI: assess pelvic spread
Management of anal cancer
- Chemoradiotherapy: most ptatients
- Surgery in:
- Tumours that fail to respond to radiotherapy
- GI obstruction
- Small anal margin tumours w/o sphincter
involvement
What’s rectal prolapse?
Protrusion of rectal tissue through the anal canal
Classification of rectal prolapse (2)
Type 1: Mucosal prolapse
- Partial prolapse of redundant mucosa
- Common in children: esp with CF
- Essentially large piles \ same Rx
Type 2: Full thickness prolapse
- Commoner CF type 1
- Usually elderly females with poor O&G Hx
Presentation of rectal prolapse
- Mass extrudes from rectum on defecation
- may reduce spontaneously or require manual
reduction
-May become oedematous and ulcerated→ pain and bleeding
- Faecal soiling
- Associated with vaginal prolapse and urinary incontinence
Clinical examination of rectal prolapse
- visible prolapse: brought out on straining
- ± excoriation and ulceration
- ↓ sphincter tone on PR
- Assoc. uterovaginal prolapse
Investigations in rectal prolapse
Si•gmoidoscopy to exclude proximal lesions
- Anal manometry
- Endoanal US
- MRI
Management of partial rectal prolapse
Partial Prolapse
- Phenol injection
- Rubber band ligation
- Surgery: Delorme’s Procedure
Conservative management of complete rectal prolapse
- Pelvic floor exercises
- Stool softeners
Surgery for complete rectal prolapse (2)
Surgery
- Abdominal Approach: Rectopexy
- Lap or open
- Mobilised rectum fixed to sacrum with mesh
- Perineal Approach: Delorme’s Procedure
- Resect mucosa and suture the two
mucosal boundaries
