Small Bowel 2 Flashcards
what is angiodysplasia
vascular abnormality of the GI tract
caused by the formation of arteriovenous malformations between previously healthy blood vessels
presents with rectal bleeding
where is angiodysplasia most commonly found
caecum and ascending colon
pathophysiology of acquired angiodysplasia
reduced submucosal venous drainage in the colon due to chronic intermittent contraction of the colon, giving rise to dilated and tortuous veins
this results in loss of pre-capillary sphincter competency and in turn causes the formation of small arteriovenous communications characterised by a small tuft of dilated vessels
clinical features of angiodysplasia
rectal bleeding and anaemia - typically presents as painless PR bleeding
chronic angiodysplasia can present with symptoms of anemia such as fatigue, weakness or dyspnoea
difference in symptoms between upper GI bleed vs lower GI bleed
upper GI = haematemesis and malaena
lower GI = haematochezia (fresh PR bleeding)
investigations into angiodysplasia
routine bloods + clotting screen
exclude malignancy - upper GI endoscopy or colonoscopy
mesenteric angiography can also be used to confirm the location of the lesion
management of angiodysplasia
depends on severity - 10% present with major GI bleeds
conservative; IV fluids and bed rest (potentially tranexamic acid), argon plasma coagulation
surgical; bowel resection (last resort in patients with major life-threatening GI bleed)
what is the main artery supplying the jejunum
superior mesenteric artery
what are the different sections of small intestine called
duodenum, jejunum and ileum
what is the most common initial presentation of a patient with a small bowel tumour
abdo pain, vomiting and constipation
from what part of the small intestine do most tumours arise from
duodenum
names of benign small bowel tumours vs malignant small bowel tumours
benign = adenomas
malignant = adenocarcinomas or neuroendocrine tumours
difference between adenocarcinomas vs neuroendocrine tumours of the small bowel
adenocarcinomas commonly affect the duodenum
neuroendocrine tumours most commonly affect the ileum
risk factors for small bowel adenocarcinomas
non-modifiable = increasing age, crohn’s, coeliac disease, FAP
modifiable; smoking, obesity, low fibre intake, high red meat intake, alcohol excess
clinical features of small bowel cancer
initially asymptomatic - first presents with small bowel obstruction due to luminal narrowing
a palpable mass may be found in 25% of cases
investigations into suspected small bowel cancer
CT imaging
if proximal then an upper GI endoscopy can be performed and a histological sample taken via biopsy
management of small bowel cancer
any symptomatic small bowel tumour requires resection - the type of resection depends on the location
duodenal tumours may require pancreaticduodenectomy (whipple’s procedure)
adjuvant chemo used in metastatic disease
when would whipple’s procedure be indicated
duodenal tumours
when would chemo be used in patients with small bowel disease
when it is lymph node positive - i.e. the lymph nodes have become involved
what would be the best management option for a previously healthy patient with a lymph node negative small bowel adenocarcinoma
wide local small bowel resection
what are neuroendocrine cells
any cell that receives input from neurotransmitters to release hormones into the bloodstream
what are Gastroenteropancreatic neuroendocrine tumours (GEP-NETs)
neuroendocrine tumours originating from the neuroendocrine cells within the GI tract or the pancreas
how are GEP-NETs further classified
into; non-functioning tumours (which have no hormone related clinical features) and functioning tumours (which cause symptoms due to peptide and hormone release)
what is Carcinoid syndrome
occurs following the metastasis of a carcinoid tumour whereby the metastasised cells begin to oversecrete bioactive mediators, such as serotonin, prostaglandins and gastrin into the circulation
present with symptoms of flushing, palpitations, abdo pain, diarrhoea
