General - anorectal

Question 1

Anal cancer

Answer 1

Relatively rare cancer
Majority of anal cancers are SCCs arising from below the dentate line
Remainder are adenocarcinomas
Pre-cancerous condition, anal intraepithelial neoplasia (AIN), may precede the development of invasive squamous anal carcinoma

Question 2

Anal cancer risk factors

Answer 2

HPV infection (HPV-16 and HPV-18)
HIV infection
Increasing age
Smoking
Immunosuppression
Crohn’s disease

Question 3

Anal cancer clinical features

Answer 3

Rectal pain/rectal bleeding
Anal discharge
Pruritis
Presence of palpable mass
Perianal infection and fistula-in-ano can be seen in locally invasive disease
Examination – perineal and perianal regions should be screened for any ulceration/presence of wart-like lesions, inguinal lymph nodes should be examined for any lymphadenopathy

Question 4

Anal cancer initial investigations

Answer 4

Proctoscopy
Undergo examination under anaesthetics (EUA), allows for much better assessment for tumour size and invasion of local structures, as well as a biopsy to be taken
Women – cervical smear
HIV test

Question 5

Anal cancer imaging

Answer 5

USS-guided fine needle aspiration
CT thorax-abdomen-pelvis
MRI pelvis

Question 6

Anal cancer management

Answer 6

MDT approach
Chemo-radiotherapy is often the first choice treatment for anal tumours (external beam radiotherapy to the anal canal and inguinal lymph nodes, combined with dual-chemotherapy agents)
Surgical excision usually reserved for management of advanced disease/in early T1N0 carcinomas (abdominoperineal resection)
Patients should be reviewed every 3-6 months for a period of 2 years

Question 7

Anal cancer complications

Answer 7

Chemoradiation-related pelvic toxicity is the most common short term complication, which can present with dermatitis, diarrhoea, proctitis and/or cystitis
Fertility issues, faecal incontinence, vaginal dryness, ED and rectovaginal fistula

Question 8

Anal fissure

Answer 8

Tear in the mucosal lining of the anal canal, most commonly due to trauma from defecation of hard stool
Acute – present for <6 weeks
Chronic – present for >6 weeks

Question 9

Anal fissure risk factors

Answer 9

Constipation
Dehydration
IBD
Chronic diarrhoea

Question 10

Anal fissure clinical features

Answer 10

Intense pain post-defecation which can last several hours
Bleeding or itching, typically post-defecation
Examination – fissures can be visible and/or palpable on DRE & most present in the posterior midline
Often patients will refuse a DRE due to intense pain & EUA may be necessary for diagnosis

Question 11

Anal fissure medical management

Answer 11

Reducing risk factors and providing adequate analgesia
Increasing fibre and fluid will help, stool softening laxatives can be trialled if no change following conservative management
Topical anaesthetics can provide short term symptomatic relief
Next line – GTN cream/diltiazem cream -> increased blood supply to the region and relaxes the internal anal sphincter, putting less pressure on the fissure

Question 12

Anal fissure surgical management

Answer 12

Reserved for chronic fissures, where medical management has failed to resolve the symptoms after at least 8 weeks
Botox injections – given into the internal anal sphincter, to relax sphincter and promote healing of the fissure
Lateral sphincterotomy – division of the internal anal sphincter muscle

Question 13

Anorectal abscess

Answer 13

Collection of pus in the anal/rectal region
More common in men than in women and have high rates of recurrence
1/3 patients with an anorectal abscess have an associated perianal fistula at the time of presentation

Question 14

Anorectal abscess pathophysiology

Answer 14

Caused by plugging of the anal ducts, which drain the anal glands in the anal wall
Blockage of an anal duct results in fluid stasis -> lead to infection, common causative organisms include E. coli, bacteriodes spp. and Enterococcus spp.
Anal glands are located in the intersphincteric space, therefore infection from the glands here spreads to adjacent areas (perianal is most common)

Question 15

Anorectal abscess clinical features

Answer 15

Severe pain in the perianal region, worse with direct pressure, alongside potential perianal discharge/bleeding
Severe – may present with systemic features
Examination – erythematous, fluctuant, tender perianal mass which may be discharging pus/have surrounding erythema and induration
Deeper abscesses – severe tenderness in PR examination

Question 16

Anorectal abscess investigations

Answer 16

Typically a clinical diagnosis
Routine bloods, HbA1c
MRI pelvis scan for patients with atypical presentation

Question 17

Anorectal abscess management

Answer 17

Should be started on abx therapy and provided with sufficient analgesia
Main management – EUA rectum and incision and drainage of the abscess, which should always be performed under general anaesthetic wherever possible
Intra-operative proctoscopy should be performed to check for the presence of any identifiable fistula-in-ano

Question 18

Haemorrhoids

Answer 18

Defined as an abnormal swelling or enlargement of anal vascular cushions (act to assist the anal sphincter in maintaining continence)

Question 19

Haemorrhoids classification

Answer 19

1st degree – remain in the rectum
2nd degree – prolapse through the anus on defecation but spontaneously reduce
3rd degree – prolapse through the anus on defecation but require digital reduction
4th degree – remain persistently prolapsed

Question 20

Haemorrhoids risk factors

Answer 20

Excessive straining
Increasing age
Raised intra-abdominal pressure
Less common risk factors – pelvic/abdominal masses, family history, cardiac failure or portal hypertension

Question 21

Haemorrhoids clinical features

Answer 21

Painless bright red rectal bleeding, commonly after defecation, blood is seen on the surface of the stool not mixed in
Pruritus, rectal fullness/anal lump, soiling
Large prolapse haemorrhoids can thrombose
Examination usually normal unless haemorrhoids have prolapsed -> present as a purple/blue, oedematous, tense & tender perianal mass

Question 22

Haemorrhoids investigations

Answer 22

Proctoscopy
FBC, clotting screen – any significant/prolonged bleeding
Colonoscopy is often advised to exclude any concurrent anorectal pathology

Question 23

Haemorrhoids conservative management

Answer 23

Nearly all managed conservatively – increasing daily fibre, fluid intake, laxatives, topical analgesia
Symptomatic 1st and 2nd degree – rubber band ligation

Question 24

Haemorrhoids surgical management

Answer 24

Haemorrhoidal artery ligation (2nd/3rd degree) – main vessel supplying the haemorrhoid is identified through Doppler and then tied off, such that the haemorrhoids infarcts and falls off
3rd and 4th degree – haemorrhoidectomy: haemorrhoidal tissue is excised, ensuring the internal sphincter muscle remains
Main complications – recurrence, anal structuring or faecal incontinence

Question 25

Perianal fistula

Answer 25

Abnormal connection between the anal canal and the perianal skin
Majority are associated with anorectal abscess
4 distinct types:
1) Inter-sphincteric
2) Trans-sphincteric
3) Supra-sphincteric
4) Extra-sphincteric

Question 26

Perianal fistula aetiology

Answer 26

Anorectal abscess
Inflammatory bowel disease
Diabetic mellitus
History of trauma
Previous radiation therapy to the anal region

Question 27

Perianal fistula clinical features

Answer 27

Recurrent perianal abscesses
Intermittent/continuous discharge onto the perineum (mucus, blood, pus or faeces)
Examination – external opening on the perineum may be seen, fibrous tract may be felt underneath the skin on DRE

Question 28

Goodsall rule

Answer 28

Used clinically to predict the trajectory of a fistula tract:
External opening posterior to the transverse anal line – fistula tract will follow a curved course to the posterior midline
External opening anterior to the transverse anal line – fistula tract will follow a straight radial course to the dentate line

Question 29

Perianal fistula investigations

Answer 29

MRI imaging

Question 30

Perianal fistula management

Answer 30

Fistulotomy – laying the tract open by cutting through skin and subcutaneous tissue, allowing it to heal by secondary intention
Placement of a seton through the fistula to bring together and close the tract, passing out at opening of the perianal skin adjacent to the external opening

Question 31

Rectal prolapse

Answer 31

Protrusion of mucosal or full-thickness of rectal tissue out of the anus
Relatively uncommon, mainly affecting older females

Question 32

Rectal prolapse pathophysiology

Answer 32

Full prolapse – form of sliding hernia, through a defect of the fascia of the pelvic region, may be caused by chronic straining secondary to constipation/chronic cough/from multiple vaginal deliveries
Partial thickness – associated with loosening and stretching of the connective tissue that attaches the rectal mucosa to the remainder of the rectal wall

Question 33

Rectal prolapse risk factors

Answer 33

Increasing age
Female gender
Multiple deliveries
Straining
Anorexia
Previous traumatic vaginal delivery

Question 34

Rectal prolapse clinical features

Answer 34

Rectal mucus discharge, faecal incontinence, PR bleeding or visible ulceration
Rectal fullness, tenesmus, repeated defecation = full thickness prolapses
Examination – prolapse can be identified by asking the patient to strain, DRE shows a weakened anal sphincter is identified

Question 35

Rectal prolapse conservative management

Answer 35

More common in those unfit for surgery/minimal symptoms/children
Increasing dietary fibre and fluid intake
Minor mucosal prolapses may be banded in clinic

Question 36

Rectal prolapse surgical management

Answer 36

Surgical repair is the only definitive management
1) Perineal approach – Delormes operation and Altemeier’s operation
2) Abdominal approach – rectopexy, whereby the rectum is mobilised and fixed onto the sacral prominence via sutures or mesh