Pathology of the small bowl Flashcards
What are the two types of ischaemia to the small bowl?
Messentary artery occlusion (due to atherosclerosis and thromboembolism).
Non-occlusive (due to shock, strangulation, drugs and hypeviscosity).
What will be most affected by an ischaemia to the small bowl and why?
The mucosa is the most metabolically active part of small intestine so it is most sensitive to the effects of hypoxia.
What is meckel’s diverticulum?
It is a congenital condition that affects 2/3% of the populatoin.
Tubular structure projects 2 inches long out of the wall of the ileum about 60cm from the ileocaecal valve.
Most are asymptomatic but some secrete HCl from their mucosa that cause GI bleeding and peptic ulcers.
What are the types of primary tumours that you can get in the small bowl?
(All primary tumours are very rare, usually cancer in the small intestine is due to metastasies).
Lymphomas - usually found in the ileum, all are non hodkins type - treat with surgery and chemo, associated with Coeliac disease.
Carcinoid tumours - usually found in the appendix.
Carcinoma - usually associated with crohn’s or coeliac.
What causes appendicitis?
Acute inflammation, mucosa ulceration, pus in the lumen.
What are the complications of appendicitis?
Rupture.
Abscess.
Sepsis and liver abscesss.
What gene is associated with Coeliac disease?
HLA-DQ8 and HLA-DQ2
What does gluten do to the enterocytes in a person with Coeliac disease?
Gliadin, the suspected toxic agent in gluten causes there to be a loss in enterocytes that leads to loss in villous structure.
What blood tests are done for coeliac disease?
Antibodies:
Anti-TTG, anti-EMA
Check full anti IgA antibodies as well
Why does appendicitis occur?
There is no definitive aetiology. However, it may be due to Faecal obstruction of the appendix or due to irratation,.
What are the symptoms of appendicitis?
Epigastric pain that migrates to the Right Iliac Fossa (RIF).
Nausea and vomiting.
Rosvings signs (pain on the right side when you palpate on the left).
Anorexia.
What investigation would be done for someone presenting with suspected appendicitis?
Ultrasound.
Bloods - CRP and WCC.
URinalysis.
Laparoscopy
How do you treat appendicitis?
If an appendix mass is there you would give antibiotics and IV fluids.
Usually though they would perform laparoscopic surgery to remove the appendix.
What causes small bowel obstuction?
Lumen: Food, gallstones.
Within the wall (Tumour, Crohn’s).
Outside the wall: (Adhesions, Herniation).
When the small bowel is obstructed what is happening distally to the obstruction?
Bowel carries on as normal until it is empty, fluid builds up and the proximal part of the small bowel begins to swell up. Creates gas formation (very smelly).
