Colorectal Surgery JC062: Anal Pain: Perianal Lesions And Sepsis Flashcards
Anorectal conditions
- Haemorrhoids
- External
- Internal - Fissure-in-ano (Anal fissures)
- Anorectal abscess
- Fistula-in-ano (Anal fistula)
- Pruritis ani
- Rectal prolapse
- Anal neoplasms
- Epidermoid carcinoma of anal canal (i.e. **SCC instead of adenocarcinoma)
- **Melanoma
- Anal margin cancers (treated as ***skin cancer)
—> SCC
—> Basal cell carcinoma
—> Kaposi’s sarcoma
Common symptoms of Anorectal conditions
記: Pain, Bleeding, Mass
- Bleeding (usually fresh blood)
- Anal pain (e.g. fissure associated with constipation)
- Discharge (blood / purulent)
- Prolapse
- Perianal mass
- Pruritis ani
- Incontinence
History taking
- Present illness (anorectal symptoms)
- pain
—> duration
—> characteristics (sharp / dull / burning, constant / intermittent)
—> association with bowel movement, bleeding / other factors
- bleeding
—> onset and duration
—> characteristics: **bright red (usually anorectal region) / altered blood / **mixed with stool
—> on paper / in bowl / on stool / in stool
—> mixed / separated with stool
—> ***black, tarry stools
—> association with bowel movements
—> association with pain - mass
- prolapse
- Past health
- medical diseases
- previous surgery (esp. in incontinent patients / bowel dysfunction) - Family history
- ***Sexual history
- infective
- related to sexual behaviour of patient
Physical examination
- General examination
- Abdominal examination
- ***Perianal examination
-
**PR examination
- **left lateral position (convenient, no need special couch, less embarrassing, buttock at side of couch, bend both hip and knee)
- ***prone Jackknife position (good for doctors, can perform procedures e.g. injection sclerotherapy / band ligation for haemorrhoids)
- need good view of anorectal mucosa + pelvic structures (e.g. prostate, pelvic organs) -
**Proctoscopy
- distal rectum
—> **early (1st / 2nd degree) of haemorrhoids cannot be felt by PR exam
Investigations
- Help in diagnosis + Assess severity
- Define anatomy of complex pathological process (abscess, fistula)
- Exclude diseases in the proximal bowel + associated bowel problems (e.g. IBD)
- Rigid sigmoidoscopy (less common now)
- 25cm in length with air sufflation —> distend + straighten rectum + ***distal colon (uncomfortable) - ***Flexible endoscopy
- require sophisticated endoscopic equipment
- can be performed in office
- mostly colonoscope now (sigmoidoscope rarely used) -
**Transrectal USG
- performed through anus **without anaesthesia in office
- can see condition / anatomy of distal rectum + anal canal
- can be used to **stage colorectal cancer (able define layers of bowel wall —> can assess depth of invasion)
- assess **sphincter muscle in faecal incontinence
- assess complex ***fistula
- inexpensive but operator-dependent - Imaging studies
- usually not necessary
- replace USG
- **MRI: accurate technique for evaluation of primary **track of fistula / any extension / depth of invasion
—> for complicated abscesses / fistula / neoplasms - Other imaging study
- **Defaecography: in patient with constipation, incontinence, rectal prolapse, rectocele —> now combined with MRI —> more dynamic picture of defaecation
- **Fistulogram: inject contrast in fistula to define track - Anorectal physiology tests
- objective tests for anorectal function
- to investigate constipation / incontinence (functional bowel diseases)
—> **Anorectal manometry (measure pressure, anorectal inhibitory reflex)
—> **Electromyogram
—> **Pudendal nerve latency test
- for documentation and assessment **after treatment
Haemorrhoids
In the past: regarded as Varicosities of anal canal
Now: ***Cushions of vascular tissue at the anal canal
- regarded as normal structure in human
- aid in continence (act as a plug)
- protect sphincters / anus from trauma of defecation
Prevalence:
- 4.4% US population seen for symptomatic haemorrhoids
- 49/100,000 US population undergo haemorrhoidectomy annually
2 types:
1. External haemorrhoids
- distal to **Dentate line
- **squamous epithelium (skin)
- nerve endings —> can be ***painful
- Internal haemorrhoids
- proximal to Dentate line
- **columnar epithelium (mucosa)
- **no nerve endings —> early haemorrhoids do not cause pain, pain only when there are complications
Causes:
- ***Exact cause unknown
- Constipation
- Straining
- Pregnancy
- Low fibre diet
- Family history
Internal haemorrhoids
Classified according to severity:
1st degree: **not prolapse out of anal canal (can only be diagnosed by proctoscope)
2nd degree: prolapse out of anal canal + reduce **spontaneously
3rd degree: require ***manual reduction
4th degree: cannot be reduced
Clinical features of Haemorrhoids
- ***Bleeding (need to distinguish from other pathologies in anorectal region / proximal colon)
- Bright red
- Blood in toilet bowl
- Not mixed with stool (SpC Revision) - ***Prolapse (mass)
- Mucus discharge
- ***Pruritis
- Pain occurs only when complications are present (***thrombosis, prolapse)
Investigations of Haemorrhoids
- PR examination
- to exclude other rectal lesions - Proctoscopy
- diagnosis + assessment of severity - Rigid / Flexible sigmoidoscopy / colonoscopy
- to exclude proximal bowel lesion (esp. ***first episode of bleeding)
Treatment of Haemorrhoids
1st + 2nd degree:
- Diet, Banding, Sclerotherapy, Infrared coagulation
3rd degree:
- Diet, Banding, Sclerotherapy, Surgery
4th degree:
- Haemorrhoidectomy
- Non-operative:
- **Diet modification: high fibre diet —> avoid constipation
- **Sitz bath (with K permanganate): for prolapsed haemorrhoids
- ***Ointments / Suppositories: may help with symptoms but some contain steroid (symptoms will recur)
- Flavonoids (Daflon) increases venotone - Operative (office procedure without anaesthesia needed):
- **Banding (Rubberband ligation)
- **Injection sclerotherapy
- Infrared coagulation - ***Surgical haemorrhoidectomy
- ***Stapled haemorrhoidopexy
- Transanal haemorrhoidal artery devascularisation
Surgical haemorrhoidectomy
- Excision of haemorrhoids
- Indications:
—> ***Severe haemorrhoids (3rd / 4th degree)
—> Mixed internal + external haemorrhoids (significant external component)
—> Failure of other treatments
—> Patient preference
—> In conjunction with another procedures
Complications of haemorrhoidectomy
- **Bleeding
- **Urine retention (esp. in BPH patients) (∵ anal pain + distention contribute to urethral spasm reflex)
- Pain
- Faecal impaction
- Infection (uncommon)
- Anal tags
- **Anal stenosis
- **Incontinence (damaged sphincter muscles)
Stapled haemorrhoidopexy
- use stapling device to remove a ring of rectal mucosa + submucosa with creation of mucosal anastomosis above Dentate line
- haemorrhoids are not excised
- haemorrhoidal tissues pulled back into anal canal from prolapsed position
- interruption of blood supply to haemorrhoids
Outcomes of stapled haemorrhoidopexy:
- **Less pain (∵ no external wound), less analgesic requirement, quicker recovery + shorter hospital stay (day procedure)
- **No wound care required
- Less post-op bleeding, wound complications
- Higher patient’s satisfaction
- **Complications can be serious (∵ performed in distal rectum rather than anal canal, stapler can catch too much tissue —> full thickness excision of rectum)
—> **Rectal perforation
—> **Severe pelvic sepsis
—> **Rectovaginal fistula
- ***Higher recurrence than conventional haemorrhoidectomy
Transanal haemorrhoidal artery devascularisation
- ↓ Bloodflow to haemorrhoids
- Insert small ***US probe into anus —> produce high frequency sound waves —> locate vessels supplying the haemorrhoids
- Each blood vessel is ***stitched closed to block blood supply to haemorrhoids —> shrinkage of haemorrhoids (require time) —> ∴ effect may not be immediate
- Added procedure: ***Anopexy —> sutures to pull external part of haemorrhoids back into anal canal
Fissure-in-ano / Anal fissure
- A split in the anoderm at the Dentate line —> may extend externally in perianal skin —> cause pain
- 90% at ***Posterior midline (∵ blood supply to that area is least —> difficult to heal)
- Anterior midline fissure (occurs in 10% women)
- Chronic fissure:
—> repeated split and healing
—> associated with **Sentinel pile (perianal skin tags), **Hypertrophic papilla and Visualisation of internal sphincter muscles at the base of fissure (require anaesthesia to examine)
Causes:
- **Hard stool
- **Tight internal anal sphincter
- Ischaemia of overlying anoderm at posterior midline
Atypical position + Multiple in number:
- **IBD (esp. Crohn’s with perianal / rectal involvement) —> avoid Sphincterotomy —> poor healing of wound
- **TB
- Syphilis
- HIV infection
- CMV
Clinical features:
1. ***Pain on defaecation
2. Fresh rectal bleeding
Diagnosis (in office):
- Spreading buttock to reveal fissure
- PR examination / Proctoscopy are painful and ***NOT indicated
Treatment of Anal fissures
Non-operative treatment
1. Bulk agents, **Stool softeners
2. **Topical anaesthetics
3. Newer topical agents to ***reduce internal sphincter pressure
- Nitroglycerin (SE: severe headache)
- CCB
- Botox injection
Operative treatment
***Lateral internal sphincterotomy
- commonest surgery for anal fissure
- deal with internal anal sphincter rather than fissure itself
- healing rate: 95%
- incontinence: 0-15%, most are minor with flatus incontinence
- be careful: not too much (incontinence) / too little (recurrence of disease)
