General Surgery - Colorectal

Question 1

what causes acute mesenteric ischaemia

Answer 1

embolism resulting in occlusion of an artery which supplies the small bowel eg SMA

Question 2

what condition is commonly associated with acute mesenteric ischaemia

Answer 2

AF

Question 3

how do patients with acute mesenteric ischaemia usually present

Answer 3

with sudden severe abdo pain which is out keeping with physical exam

Question 4

how is acute mesenteric ischaemia managed and whats the prognosis

Answer 4

surgically, poor prognosis

Question 5

what are the risk factors of anal cancer

Answer 5

HPV (16 or 18)
anal intercourse
men who have sex with men
HIV & immunosupressive meds
women with history of CIN
smoking

Question 6

80% of anal cancers are what kind

Answer 6

squamous cell carcinomas

Question 7

how do those with anal cancer typically present

Answer 7

perianal pain and bleeding
palpable lesion
faecal incontinence
neglected tumour in female may present with rectovaginal fistula

Question 8

how is anal cancer staged

Answer 8

T1s - carcinoma in situ
T1 - tumour 2cm or less
T2 - tumour 2cm-5cm
T3 - tumour >5cm
T4 - tumour that invades any organ

Question 9

what usually causes anal fissures

Answer 9

increased anal resting pressure
trauma
constipation
also secondary to IBD, infection and malignancy

Question 10

how do patients with anal fissure usually present

Answer 10

severe rectal pain
rectal bleeding
pruritus ani
constipation

Question 11

how are anal fissures diagnosed

Answer 11

history and clinical exam with additional investigations are needed

Question 12

what are the different ways in which an anal fissure can be managed

Answer 12

conservative - sitz baths, stool softeners, fibre supplementation and topical analgesics

medical - topical nitroglycerin, CCB and botulinum toxin injections

surgical - lateral internal sphincterotomy for refractory cases

Question 13

which patients is chronic mesenteric ischaemia most usually seen in

Answer 13

elderly patients with history of smoking, hypertension and hyperlipidaemia

Question 14

what are the symptoms of CMI

Answer 14

abdo pain (typically 30 min-2hr post meal, food aversion)
weight loss
nausea
vomiting
diarrhoea

Question 15

how is CMI usually diagnosed

Answer 15

imaging studies such as CT angiography or magnetic resonance angiography

Question 16

what are the treatment options for CMI

Answer 16

medical management
endovascular interventions
surgical revascularisation

Question 17

what are the three different types of colon cancer

Answer 17

sporadic (95%)
HNPCC (5%)
FAP (<1%)

Question 18

what are the features of HNPCC

Answer 18

autosomal dominant condition, often causes cancer of proximal colon

also develop endometrical cancer

Question 19

how is HNPCC diagnosed

Answer 19

amsterdam criteria
- at least 3 family members with colon cancer
- the cases span at least two generations
- at least one case diagnosed before age 50

Question 20

what are the features of FAP

Answer 20

autosomal dominant, leads to formation of hundreds of polyps by age 30-40

patient inevitably develops carcinoma so patients generally have total colectomy with ileo-anal pouch formation in twenties

Question 21

what other tumours are those with FAP at risk of

Answer 21

duodenal tumours

Gardners syndrome - osteomas of skull and mandible, retinal pigmentation, thyroid carcinoma and epidermoid cysts on skin