General - Anorectal Flashcards
Define an anal fissure
Tear in the mucosal lining of the anal canal
How are anal fissures classified?
Acute: <6wks
Chronic: >6wks
What are the risk factors for anal fissures?
Inflammation or trauma to anal canal:
- Constipation
- Dehydration
- IBD
- Chronic diarrhoea
What are common presenting features of anal fissures?
- Intense pain post defecation (lasting several hours)
- Bleeding (bright red on wiping)
- Itching
Where do anal fissures most commonly occur?
Posterior midline
How is an anal fissure often diagnosed?
DRE conducted anaesthesia
Fissures can be identified upon proctoscopy
How are patients with anal fissures medically managed?
- Increase of dietary fibre and fluids
- Stool softening laxatives (eg. movicol or lactulose)
- GTN or diltiazem cream
Why is GTN or diltiazem cream used?
Increases blood supply to the region and relaxes the internal anal sphincter –> puts less pressure on the fissure and promotes healing and reducing pain
When is surgical therapy used to treat anal fissures?
Chronic fissures where medical treatment has failed
What surgery is indicated for anal fissures?
Lateral sphincterotomy
Define an anal fistula
An abnormal connection between the anal canal and the perianal skin. Associated with anorectal abscess formation
What risk factors are there for anal fistula formation?
- Anal abscess
- IBD
- Systemic disease eg. TB, Diabetes, HIV
- History of trauma
- Previous radiation therapy to anal region
What will an anal fistula commonly present with?
- Intermittent or continuous discharge
- Severe pain
- Swelling
- Change in bowel habit
- Systemic features of infection
What may be found on examination of an anal fissure?
- An external opening on the perineum (fully opened or covered in granulation tissue)
- Fibrous tract may be felt on DRE
What is the Goodsall rule used for?
Used to predict the trajectory of a fistula tract
What does the Goodsall rule predict in a fistula tract with the external opening POSTERIOR to the transverse anal line?
Fistula tract will follow a curved course to the posterior midline
What does the Goodsall rule predict in a fistula with an opening ANTERIOR to the transverse anal line?
Fistula tract will follow a straight radial course to the dentate line
What imaging modality is indicated for an anal fistula?
Rigid sigmoidoscopy - visualised the opening in the tract in the anal canal
Briefly describe Park’s classification system
- Intersphincteric fistula (most common)
- Transphincteric fistula
- Suprasphincteric fistula (least common)
- Extra sphincteric fistula
What surgical treatment is available for anal fistulas?
- Fistulotomy
- Seton placement
- +/- Opening perianal skin adjacent to external opening
When should surgery not be performed for an anal fistula?
- If patient is asymptomatic –> conservative
- Acute anorectal abscess
In which types of anal fistulas are there higher risks of incontinece post operatively?
High tract course fistula (travels through more subcut tissue and muscle)
What is thought to cause anorectal abscesses?
Plugging of the anal canal ducts causing stasis, allowing the normal bacterial flora to overgrow and cause infection
What are the common causative organisms involved in anorectal abscesses?
E coli
Bacteriodes
Enterococcus
How are anorectal abscesses catergorised?
- Perianal (most common)
- Ischiorectal
- Intersphincteric
- Supralevator
How will an anorectal abscess typically present?
- Perianal pain, exacerbated when sitting down
- Localised swelling
- Itching
- Discharge
- Systemic features if severe
Which type of anorectal abscess is most likely to have systemic symptoms?
Ischiorectal abscesses
What may be seen on examination of an anorectal abscess?
Red and tender abscess, discharging purulent or haemorrhage fluid
May be some surrounding cellulitis
What imaging may be done for complicated anorectal abscesses?
MRI scan
Why is there little scope for conservative management of anorectal abscesses?
High rates of recurrence and development of fistulae
When may antibiotics be indicated in anorectal abscess management?
Acute infective states, especially in diabetics or immunocompromised patients
What management is indicated for anorectal abscesses?
Surgical drainage followed by packing
How should an abscess be left to heal?
By secondary intention - early closure is not advised
What is pilonidal sinus disease?
Disease of the anorectal region, characterised by the formation of a sinus in the cleft of the buttocks
What group of people does pilonidal sinus disease commonly affect?
Caucasian males aged 15-30 years
Classically those who sit for prolonged periods of time
Briefly outline the pathophysiology of pilonidal sinus disease
- Hair follicle in the intergluteal cleft becomes infected or inflamed
- Inflammation obstructs the opening of the follicle, which extends inwards to form a pit
- Foreign body type reaction can lead to the formation of a cavity, connected to the skin surface
What risk factors are there for pilonidal sinus disease?
- Male
- Coarse, dark body hair
- Increased sweating
- Prolonged sitting
- Friction in buttocks
- Obesity
- Poor hygiene
- Local trauma
Describe the classical clinical presentation of pilonidal sinus disease
Intermittent red, painful and swollen mass in the sacrococcygeal region
Commonly has discharge +/- systemic symptoms
What is the main distinguishing feature between a pilonidal sinus and an anal fistula?
Sinus opens up onto the skin but does not continue into the anal canal
What imaging method can be used to differentiate between a pilonidal sinus and a fistula?
Rigid sigmoidoscopy
What is the conservative management for pilonidal sinus disease?
Shaving of affected region and plucking the sinus free of any embedded hair
What is the management for an acute pilonidal sinus abscess ?
Drainage and washout of the abscess
+ later removal of sinus tract
How is chronic pilonidal sinus disease managed?
Removal of pilonidal sinus tract
Over what age does the incidence of pilonidal sinus disease reduce?
40 years
What is the most common type of anal cancer? Where does this occur?
Squamous cell carcinoma - arises below the pectinate line
Where do adenocarcinomas in the anus tend to occur?
Upper anal canal epithelium and crypt glands
What is anal intraepithelial neoplasia?
Precedes the development of invasive squamous cell anal cancer. Can affect either the perianal skin or anal canal.
What is anal intraepithelial neoplasia linked to?
HPV 16 and HPV 18 infection
How is anal intraepithelial neoplasia graded?
Dependent on the degree of cytological atypical and the depth of it into the dermis
At what grade of anal intraepithelial neoplasia do we determine it as premalignant?
High grade AIN (2 or 3)
What are the risk factors for development of anal cancer?
- HPV infection
- HIV infection
- Increasing age
- Smoking
- Immunosupressant medication
- Crohns disease
What are the main symptoms of anal cancer?
- Pain
- Rectal bleeding
- Anal discharge
- Pruritus
- Palpable mass
What symptoms might be seen in invasive anal cancer?
- Perianal infection and fistula-in-ano
- Faecal incontinence + tenesmus (if sphincters involved)
What should be looked for on examination of suspected anal cancer?
- Ulceration of the perineum and perianal region
- Wart like lesions
- Vaginal examination
- DRE (if possible)
What should be documented about a DRE for anal cancer?
Distance of the mass from the anal verge + fraction of anal circumference it occupies
What are the main differential diagnoses for anal pathology?
- Haemorrhoids
- Anal fissure
- Fistula in ano
- Anal warts
- Low rectal cancer
- Skin cancer
What investigation can be done to visualise the anal canal?
Proctoscopy
What definitive diagnostic investigation should be done for all patients with suspected anal cancer?
Examination under anaesthetic with a biopsy for histology
Why should a smear test be done in females with suspected anal cancer?
To exclude cervical intraepithelial neoplasia (CIN)
What imaging is required for staging of anal cancer?
- USS guided fine needle aspirate of any palpable inguinal lymph nodes
- CT thorax-abdo-pelvis (for mets)
- MRI pelvis (assess extent of local invasion)
What is first line management for anal cancer?
Chemo-radiotherapy
–> external beam radiotherapy into anal canal and inguinal nodes + dual chemotherapy agents
When is surgical excision of an anal cancer indicated?
- Advanced disease
- After failure of chemo-radiotherapy
- Early T10 carcinoma
What surgical approach is used for excision of anal cancers?
Abdominoperineal resection
When do recurrences of anal cancer tend to occur?
Within the first 3 years
What short term complications are there of anal cancer?
Chemoradiation related pelvic toxicity:
- Dermatitis
- Diarrhoea
- Procitits
- Cystitis
- Leucopenia
- Thrombocytopenia
What long term complications are there of anal cancer?
- Fertility issues
- Faecal incontinence
- Vaginal dryness
- Erectile dysfunction
- Rectovaginal fistula
Define a haemorrhoid
An abnormal swelling or enlargement of the anal vascular cushions
What are the anal vascular cushions?
Assist the anal sphincter in maintaining continence
There are 3 : 3, 7 and 11 o’clock positions (if anterior is 12)
Briefly describe the classification of haemorrhoids
1st degree: Remain in the rectum
2nd: Prolapse through the anus on defecation but spontaneously reduce
3rd: Prolapse through the anus on defecation but require digital reduction
4th: Remain persistently prolapsed
What are the risk factors for haemorrhoids?
- Excessive straining
- Increasing age
- Raised intra abdominal pressure
- Pelvic/abdo masses
- FHx
- Cardiac failure
- Portal hypertension
What is the typical presentation of a haemorrhoid?
- Painless bright rectal bleeding - commonly after defecation + seen on paper or covering the pan (ie. not mixed in)
- Pruritus
- Rectal fullness
- Soiling
What may happen to a large, prolapsed haemorrhoid?
They can thrombose - very painful and can be an emergency
What will a thrombosed prolapsed haemorrhoid look like?
A purple/blue, oedematous, tense and tender perianal mass
What investigation is used to confirm haemorrhoids?
Proctoscopy
What non surgical management can be given for haemorrhoids?
- Rubber band ligation *
- Infrared coagulation/photocoagulation
- Bipolar diathermy
- Direct-current electrotherapy
What surgical option is there for haemorrhoids?
Haemorrhoidectomy (stapled or Milligan Morgan)
What are the main complications of haemorrhoidectomy?
- Bleeding
- Infection
- Constipation
- Stricture
- Anal fissures
- Faecal incontinence
What complications are there of haemorrhoids?
- Thrombosis
- Ulceration
- Gangrene
- Skin tags
- Perianal sepsis
What is a rectal prolapse?
Where a mucosal or full-thickness layer of rectal tissue protrudes out of the anus
What are the two main types of rectal prolapse?
- Partial thickness (rectal mucosa protrudes out of anus)
- Full thickness (rectal wall protrudes out of anus)
What is the pathophysiology of a full thickness rectal prolapse?
Form of sliding hernia through a defect of the fascia of the pelvic region
Caused by chronic straining
What is the pathophysiology of a partial thickness rectal prolapse?
Associated with loosening and stretching of the CT attaching the rectal mucosa to the remainder of the rectal wall
(often in conjunction with haemorrhoids)
What is the typical presentation of a rectal prolapse?
- Rectal mucous discharge
- Faecal soiling
- Bright red blood on wiping
- Visible ulceration possible
What may a full thickness prolapse present with if internal?
- Sensation of rectal fullness
- Tenesmus
- Repeated defecation
How can a prolapse be identified on examination?
Asking the patient to strain
DRE - assess for weakened sphincter tone
What can be used to identify an internal prolapse?
Defecating proctography + examination under anaesthesia
What is the definitive management of a rectal prolapse?
Surgical repair - either abdominal or perianal procedure
What is the abdominal approach to surgical repair of a rectal prolapse?
Rectopexy - mobilisation of rectum and fixing onto sacral prominence
What are the two operations that can be used for a perianal approach to repair of a rectal prolapse?
Delormes
Altmiers (more effective
