Pathology of the small intestine Flashcards
What are the 2 classes of conditions that can lead to ischaemia of the small bowel?
Mesenteric arterial occlusion
Non-occlusive perfusion insufficiency
What are some conditions that can lead to mesenteric artery occlusion?
Mesenteric artery atherosclerosis
Thromboembolism from the heart
What are some conditions that can lead to non-occlusive perfusion insufficiency?
Shock
Strangulation obstructing venous return
Drugs (e.g. cocaine)
Hyperviscosity
What is the progression of mesenteric ischaemia?
Mucosal infarction
Mural infarction
Transmural infarction
Necrosis
gangrene
Bowel perforation
What are some symptoms of acute mesenteric ischaemia?
Nausea
Vomiting
Abdominal pain
Who is most at risk of chronic mesenteric ischaemia?
Females
Aged 50-70
History of atherosclerosis
Smoking
Atrial fibrillation
What are some symptoms of chronic mesenteric ischaemia?
Moderate-to-severe colicky, poorly localised pain (Angina of the bowel)
Weight loss
Postprandial pain
Fear of eating
Nausea
Vomiting
Bowel irregularity
What are some investigations that can be performed in mesenteric ischaemia?
CT angiography - Gold standard
Bloods => Lactate raised, CRP normal
What are some possible complications of untreated mesenteric ischaemia?
Fibrosis
Stricture
Mesenteric angina
Obstruction
Gangrene
Perforation
What are some treatment options in mesenteric ischaemia?
Bowel resection
SMA embolectomy
Where do most secondary tumours of the small intestine metastasise from?
Ovaries
Stomach
Colon
What are the 3 main primary tumour types of the small intestine?
Non-hodgkin lymphomas
Neuroendocrine tumours
Carcinomas
What are the 2 main types of lymphoma that can affect the small intestine?
Maltomas (B-cells)
Enteropathy associated T cell lymphomas (Associated with Coeliac disease)
What are some paraneoplastic syndromes associated with neuroendocrine tumours of the small intestine?
Flushing
Diarrhoea
What is appendicitis?
Inflammation of the appendix, usually caused by obstruction of the appendiceal lumen
Who is acute appendicitis most common in?
It is the most common cause of acute abdomen in children and young adults, affecting most people in their 2nd and 3rd decade
What are some common causes of appendicitis?
Idiopathic
Faecolith blockage (Dehydration)
Lymphoid hyperplasia
Parasites
Tumours
What is a faecolith?
A small, dehydrated ball of faecal matter, caused by a decrease in fluid intake
How can blockage of the appendiceal lumen lead to appendicitis?
Blockage causes entrapment of bacteria, which grow , causing damage to the mucosa, leading to neutrophilic activation and pus build up, which can cause ischaemia of surrounding veins, resulting in necrosis and perforation
What are some possible complications of untreated appendicitis?
Rupture
Peritonitis
Abscesses
Fistula
Sepsis
Liver abscesses
Describe the pain felt in acute appendicitis?
Starts poorly localised to the umbilical region as visceral afferent nerves enter the spinal cord at T8 - T12
As the appendix becomes inflamed, it begins to rub against the soma, therefore causing stimulation of somatic sensory nerves, which localise the pain the the right iliac fossa
What is McBurney’s point?
The theoretical point of maximum tenderness in appendicitis
It is found 1/3rd of the way between the superior anterior iliac spine and the umbilicus
What is the usual presentation of a patient with appendicitis?
Umbilical pain that has moved down to RIF
Worse on coughing or laughing
Colicky pain
Hasn’t opened bowels that day
What are some possible clinical signs in appendicitis?
Mild pyrexia
Mild tachycardia
Guarding
Rebound
Rovsing’s sign
Psoas sign
Obturator sign
