Pathology of the Small Bowel Flashcards
What can cause ischaemia of the small bowel?
Mesenteric artery occlusion or non-occlusive perfusion insufficiency
What can cause non-occlusive perfusion insufficiency?
Shock, strangulation obstructing venous return (hernia), drugs, hyperviscosity
What usually occurs after a mucosal infarct?
Regeneration and the mucosal integrity is restored
What usually occurs after a mural infarct?
Repair and regeneration leading to fibrosis and stricture
What usually occurs after transmural infarct?
Gangrene and death if not resected
Complications of ischaemia of the small bowel
Resolution, fibrosis, stricture, chronic ischaemia, ‘mesenteric angina’, obstruction, gangrene, perforation, peritonitis, death
Meckel’s diverticulum
Result of incomplete regression of vitello-intestinal tract
Describe structure and position of Meckel’s diverticulum
Tube structure, 2 inches long, 2 foot above ileocaecal valve in 2% of people
Complications of Meckel’s diverticulum
Bleeding, perforation or diverticulitis which mimics appendicitis
Primary tumours of the small bowel
Lymphomas, carcinoid tumours, carcinomas
Where can secondary tumours of the small bowel metastasise from?
Ovary, colon, stomach
What type of lymphoma is associated with the small bowel?
Hodgkins lymphoma
Treatment of lymphomas of the small bowel
Surgery and chemotherapy
Most common site of carcinoid tumours of the small bowel
Appendix
Describe carcinoid tumours of the small bowel
Small, yellow, slow growing, locally invasive
What can carcinoid tumours of the small bowel cause?
Intussusception
Symptoms of carcinoid tumours of the small bowel
Flushing and diarrhoea
Which diseases is carcinoma of the small bowel associated with?
Crohn’s and coeliac disease
Where can carcinoma of the small bowel metastasise to?
Lymph node and liver
Most common cause of acute abdomen
Appendicitis
Pathology of appendicitis
Acute inflammation by neutrophils, mucosal ulceration, serosal congestion, exudate, pus in lumen
Complications of appendicitis
- Peritonitis
- Rupture
- Abscess
- Fistula
- Sepsis and liver abscess
What is coeliac disease caused by?
Abnormal reaction to a constituent of wheat flour, gluten, which damages enterocytes and reduces absorptive capacity.
What is the suspected toxic agent in coeliac disease?
Gliadin
Enterocytes in coeliac disease
Increasing loss of enterocytes due to intraepithelial lymphocyte mediated damage
Metabolic effects of coeliac disease
- Malabsorption of sugars, fats, amino acids, water and electrolytes
- Malabsorption of fats leads to steatorrhea
- Reduced intestinal hormone production leads to reduced pancreatic secretion and bile flow leading to gallstones
Effects of malabsorption in coeliac disease
Weight loss, anaemia, abdominal bloating, failure to thrive, vitamin deficiencies
Complications of coeliac disease
- T-cell lymphomas of GI tract
- Increased risk of small bowel carcinoma
- Gall stones
- Ulcerative-jejenoilleitis
Aetiology of appendicitis
Obstruction of lumen by faecolith or tumour, bacterial, viral, parasitic
Symptoms of appendicitis
Colicky abdominal pain starting around umbilicus which shifts to the right iliac fossa which is worse on coughing/going over speed bumps etc, put off food, nausea and vomiting, flushed
Signs of appendicitis
Mild pyrexia, mild tachycardia, guarding, rebound tenderness, high WCC
Signs specific to appendicitis
Rosving’s sign, Psoas, Obturator
Rosving’s sign
Pressing on left side causes pain in right
Psoas
Patient keeps the right hip flexed as this lifts an inflamed appendix off the psoas
Obturator
If appendix is touching obturator internus, flexing the hip and internally rotating will cause pain
Differential diagnosis of appendicitis in children
- Gastroenteritis – vomiting profusely and lots of diarrhoea
- Mesenteric adenitis – lymph nodes in mesentery swell up and stretch the peritoneum and causes pain
- Meckel’s diverticulum
- Intussusception
- Henoch-Schonlein purpura – rash on ankles
- Lobar pneumonia
Differential diagnosis of appendicitis in adults
- Terminal ileitis – colicky paint that comes and goes
- Ureteric colic
- Acute pyelonephritis
- Perforated ulcer
- Pancreatitis
- Rectus sheath haematoma
- Ectopic pregnancy
Differential diagnosis of appendicitis in elderly
- Sigmoid diverticulitis
- Intestinal obstruction
- Carcinoma of the caecum
Investigations for appendicitis
Clinical diagnosis, ultrasound, abdominal X-ray, bloods (CRP, WCC), urinanalysis
What score can be used to clinically diagnose appendicitis?
MANTRELS score
MANTRELS score
M = migration of pain to RLQ A = anorexia N = nausea and vomiting T = tenderness in right lower quadrant R = rebound pain E = elevated temperature L = leucocytosis S = shift of white blood count to left
Management of appendicitis
Analgesia, antipyretics, antibiotics, appendectomy
Treatment for appendix mass
Antibiotics, can operate (if able to), theatre if antibiotics failed or complications
Complications of appendix mass
Tachycardia, worsening pain, increase in size, vomiting or copious NG aspirated
Complications of appendectomy
Pelvic abscess, wound infection, intra-abdominal abscess, ileus, DVT/PE, portal pyaemia, faecul fistula, adhesions, right sided inguinal hernia
Carcinoid of the appendix - what is it a tumour of?
Crypts of Lieberkuhn
Clinical presentation of small bowel obstruction
Colicky pain, absolute constipation, nausea and vomiting (may be faeculent), burping, abdominal distension, loud vomiting ischaemia and perforation
Causes of small bowel obstruction (within the lumen)
Gallstone, food, bezoar
Causes of small bowel obstruction (within the wall)
Tumour, Crohn’s radiation
Causes of small bowel obstruction (outside the wall)
Adhesions, herniation
Treatment of small bowel obstruction
“drip and suck” - put in a drip and suck out air via NG tube, ABC, analgesia, catheterise, antithromboembolise
How long do you drip and suck?
Up to 72 hours
In surgery, how is the obstruction of the bowel found?
By following the collapsed or dilated bowel
Causes of mesenteric ischaemia
Embolus usually from atrial fibrillation, in situ thrombosis from general gubbedness
Diagnosis of mesenteric ischaemia
Pain out of proportion to clinical findings, acidosis, elevated lactate
Investigations for mesenteric ischaemia
CT angiogram
Which surgical procedure is required for treatment of mesenteric ischaemia
Laparotomy
Haemorrhage of the small bowel:
- Often caused by what?
- Investigation
- Management
- Vascular malformations or ulceration
- CT angiography
- Interventional radiology
Complications of Meckel’s diverticulum
Bleed, ulceration, Meckel’s diverticulitis, obstruction, malignancy