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)
Anorectal abscess / infection
Causes:
1. **Cryptoglandular infection (infected anal glands)
2. Specific infections / diseases
- **IBD
- **TB
- Actinomycosis
- Foreign body
- **Surgery (e.g. haemorrhoidectomy, lateral internal sphincterotomy)
- Malignancies
Locations of abscess:
1. **Perianal abscess (20%)
2. **Ischiorectal abscess (drainage through external sphincter) (60%)
3. **Intersphincteric abscess (∵ most anal glands located here) (18%)
4. Supralevator abscess (mainly from **pelvic infections e.g. diverticular diseases) (2%) —> never drain through perianal region —> will become a high fistula
Clinical features:
1. Pain
2. ***Swelling
3. Drainage
4. Constipation
5. Urinary difficulties
Treatment of Anorectal abscess
- Incision + ***drainage of abscess
- ***Little role for antibiotics
- except in patients with severe cellulitis, valvular heart disease, prosthetic heart valves, immunosuppression, leukaemia, lymphoma - ***Primary fistulotomy
- depends on experience
- may cause more damage to sphincter muscle
Fistula-in-ano
- Abnormal tract communicating between 2 epithelial surface (perianal skin to rectum / anal canal)
- 50% after abscess drainage will develop fistula
Cause:
- ***Cryptoglandular infection
- Crohn’s disease
- TB
- HIV
***Classification (Parks classification):
1. Intersphincteric
2. Transphincteric (fistulotomy / fistulectomy may damage sphincter muscles)
3. Extrasphincteric (mostly iatrogenic ∵ drainage of supralevator abscess / damage to levator muscles during surgery)
4. Suprasphincteric
Goodsall’s rule (wiki):
- If the perianal skin opening is posterior to the transverse anal line, the fistulous tract will open into the anal canal in the midline posteriorly, sometimes taking a curvilinear course
- A perianal skin opening anterior to the transverse anal line is usually associated with a radial fistulous tract
- Tell where the internal opening is
Clinical features:
1. **Drainage
2. Pain
3. Bleeding
4. Swelling
5. ↓ Pain when drainage
6. **External opening
7. ***PR exam: induration with cord-like structure (indurated tract felt at perianal area)
Diagnosis of Fistula-in-ano
- Clinical examination
- for lower fistula, first attack - ***MRI
- for complicated high fistula, recurrent fistula, when anatomy is not obvious
Treatment of Fistula-in-ano
Simple low fistula
1. **Fistulotomy (成條同出面皮膚打通)
2. **Fistulectomy (撩空條tract)
- risk of ***incontinence should be informed
Complicated high fistula / Transphincteric fistula with significant amount of muscle involvement
1. **Seton (staged procedure (越綁越緊))
2. Endorectal advancement flap
3. Anal fistula plug (now considered ineffective)
4. **Ligation of intersphincteric fistula tract (LIFT) (very low incontinence rate)
Perianal abscess (SpC Revision):
1. Incision + Drainage
Pruritis ani
- Itchiness in perianal region —> Scratching leads to ***excoriation + secondary infection
- 1-5% of population
- common in 5th / 6th decades
Causes:
- **personal hygiene
- diet
- systemic diseases
- **dermatological conditions
- neoplasm
- infection
- psychogenic
- drugs
- diarrhoea
- idiopathic
Approach to Pruritis ani
- Identify etiology + treat appropriately
- Idiopathic
- Reassurance
- **Keep perianal skin dry
- **Avoid soap / local applications
- ***Avoid prolonged topical steroids
- Dietary change
Rectal prolapse
- ***Full thickness protrusion of rectum through anal sphincter
- Internal prolapse: rectum intussuscept but does not pass beyond anus
- Occurs in any age but more commonly at extremes of life
- More common in female
Associated anatomical abnormalities (do not know whether cause / result)
- **Rectal intussusception
- **Deep cul de sac
- Loss of rectal fixation
- Redundant sigmoid
- Levator ani diastasis
- ***Patulous anal sphincter
- Pudendal neuropathy (prolapse —> stretching of pudendal nerve —> incontinence)
Causes:
- **Neurological disorders
- **Parity
- **Constipation (25-50%)
- Childhood: cystic fibrosis, whooping cough, developmental abnormalities, malnutrition (∵ **↑ intraabdominal pressure)
Clinical features:
1. **Incontinence (∵ stretching of pudendal nerve)
2. **Constipation
3. **Protrusion
4. Bleeding
5. Discharge
6. **Sensation of incomplete emptying
7. Rectal pressure / Tenesmus
Treatment of Rectal prolapse
None is really effective
Abdominal repair
1. **Rectal fixation (suture / mesh) (to sacrum)
2. **Sigmoid resection
3. **Proctectomy
4. Combination of rectal fixation + sigmoid resection
5. Others options by abdominal approach: Suture, Mesh, Resection, Laparoscopic vs Open vs Robotic —> most popular: **Laparoscopic ventral mesh rectopexy
***Perineal repair (less major impact on patient)
1. Full thickness resection
2. Mucosal resection with muscular reefing
3. Anal encirclement
