W7: Pancreas: Anatomy, Physiology Pancreatitis & Pancreatic Tumours Flashcards
What are the 5 anatomical segments of the pancreas?
- head
- neck
- body
- tail
- uncinate process
What 2 vessels that branch from the aorta give the pancreas its arterial blood supply?
- Celiac trunk
- superior mesenteric artery
What does the gastroduodenal artery split into to supply the head of the pancreas?
- anterior superior pancreaticoduodenal artery
- posterior superior pancreaticoduodenal artery
What vessel branches from the splenic artery to supply the neck, body and tail of the pancreas?
dorsal pancreatic artery
What 2 vessels branch fro the superior mesenteric artery to supply the uncinate process of the pancreas?
- anterior inferior pancreaticoduodenal artery
- posterior inferior pancreaticoduodenal artery
What venous blood vessel passes behind the pancreas and changes name as it drains into the liver?
Inferior mesenteric vein to portal vein
What three blood vessels branch from the superior mesenteric vein to supply venous drainage to the head and uncinate process of the pancreas?
- anterior inferior pancreaticoduodenal vein
- posterior inferior pancreaticoduodenal vein
- anterior superior pancreaticoduodenal vein
What blood vessel branches from the portal vein to give venous drainage to the head and uncinate process of the pancreas?
posterior superior pancreaticoduodenal vein
What three veins supply venous drainage to the neck, body and tail of the pancreas?
- splenic vein
- inferior mesenteric vein
- inferior pancreatic vein
What is the ampulla of vater?
where the bile duct and pancreatic duct meet to drain into the duodenum
What two ducts meet to form the common bile duct?
- Cystic duct
- common hepatic duct
What cells of the pancreas carry out the exocrine function and what do they secrete?
- acinar cells
- secrete pancreatic enzymes
What cells of the pancreas carry out the endocrine function and what do they secrete?
- Islets of Langerhans
- secrete hormones into blood
Approximately how much of the exocrine pancreas comprises of the parenchyma?
98%
What are the 4 cells in the Islet’s of Langerhan’s and which are there most of?
- alpha cells
- beta cells (most of these)
- delta cells
- F cells
What do beta cells of the pancreas secrete?
insulin
What do alpha cells of the pancreas secrete?
glucagon
What do delta cells secrete?
somatostatin
What do F cells secrete?
pancreatic polypeptide
What regulates secretion of pancreatic fluid from the acinar cells?
- vagus nerve
- gastrin levels
What are 3 major types of enzymes secreted in pancreatic fluid?
- protease
- pancreatic lipase
- pancreatic amylase
List two types of proteases secreted in pancreatic fluid?
- Trypsin
- Chymotrypsin
What are 4 additional enzymes (other than proteases, lipase and amylase) secreted in pancreatic fluid?
- ribonuclease
- deoxyribonuclease
- gelatinase
- elastase
What two substances are secreted by the epithelial cells lining the pancreatic ducts?
- water
- bicarbonate
Approx. how much pancreatic fluid is secreted a day?
1 litre
In terms of the causes of acute pancreatitis, what does the acronym “I GET SMASHED” stand for?
- Idiopathic
- Gallstones
- Ethanol
- Trauma
- Steroids
- Mumps (+ coxsackie B + viral Hepatitis, adenovirus, HIV)
- Autoimmune
- Scorpion bite
- Hypercalcaemia, Hyperparathyroidism, Hyperlipidaemia
- ERCP
- Drugs (azathoprin)
What is the function of cholecystokinin and from where is it secreted?
- stimulates release of bile
- secreted by epithelial cells in the duodenum
What is the pathophysiological theory of acute pancreatitis?
- blocked CBD or PD causes reflux of bile into pancreas and activation of enzymes
- release of pancreatic enzymes that then autodigest the pancreas
Why is activation of trypsinogen to trypsin in the pancreas particularly detrimental to acinar cells in acute pancreatitis?
Active trypsin cleaves and activates all the other pancreatic enzymes
An increase in what intracellular mineral is thought to activate trypsinogen?
Calcium
What are the 4 main stages of acute pancreatitis?
- Hypovolaemic shock + hypocalcaemia
- retroperitoneal haemorrhage
- pancreatic necrosis
- abscess formation
What leads to hypovolaemic shock in the first stage of acute pancreatitis?
oedema and fluid shifts
What leads to hypocalcaemia in the first stage of acute pancreatitis?
fats are autodigested in the peritoneal cavity meaning Ca++ binding is affected
What leads to retroperitoneal haemorrhage in acute pancreatitis?
autodigestion of blood vessels
What leads to abscess formation in acute pancreatitis?
Necrotic pancreatic tissue becoming infected
What is DIC?
Disseminated Intravascular Coagulation -> overactive blood clotting
What can cause shock, pulmonary compromise, acute renal failure and DIC following necrosis in acute pancreatitis?
Release of toxic metabolites into blood
How does a pseudocyst form in acute pancreatitis?
Inflammation can lead to peripancreatic exudation or pancreatic duct leakage
What are the clinical symptoms of acute pancreatitis?
- acute onset epigastric pain/upper abdo
- pain radiating to back
- getting progressively severe
- nausea and vomiting
- jaundice
What can be found upon examination of a patient with acute pancreatitis and when severe?
- diffuse upper abdominal tenderness
- maybe fullness in epigastrium due to pseudocyst
- if severe: widespread guarding and absent bowel sounds
What are three classic signs on the abdomen of a patient with acute pancreatitis and describe these?
- Grey Turner’s sign (flank bruising)
- Cullen’s signs (periumbilical bruising)
- Erythema Abigne (hyperpigmentation, fish-net like erythema)
What are the main investigations carried out in acute pancreatitis?
- Bloods
- arterial blood gas
- xray
- ultrasound
- CT
- ultrasound
What are the specific blood tests in investigating acute pancreatitis? (10)
- FBC
- coagulation
- U&Es
- LFTs
- amylase serum
- lipase serum
- blood glucose
- plasma calcium
- crp
- lactate
How can acute pancreatitis lead to hypoxia/ARDS?
Due to the increased levels of activated trypsinogen in the blood causing damage to the pulmonary vasculature
What are two possible signs of acute pancreatitis in xray and explain why these signs can occur?
- pleural effusion -> due to disrupted pancreatic duct leading to fistula or pseudocyst rupture
- sentinel loop -> dilatation of part of small intestine due to localised inflammation
What is the purpose of ultrasound scanning used in the investigation of acute pancreatitis?
To find:
- gallstones
- common bilde duct size
- cholecystitis
- peripancreatic fluid (free fluid)
What is the purpose of carrying out a CT scan and when should it be done?
- To assess the degree of pancreatic damage
- should be done after 72hr of pancreatitis
List 5 complications that can be picked up in follow up CT scan after acute pancreatitis?
- abscess
- ascites
- bleeding
- fluid collections
- pancreatic necrosis
When is ERCP used in acute pancreatitis?
As treatment for CBD stones obstructing bile duct
What is the treatment to prevent a recurrent pancreatitis when its caused by gallstone obstruction?
Cholecystectomy
What is treatment following pancreatitis with more than 50% necrosis?
- antibiotics
- percutaneous draining
- endoscopic necrosectomy - debridement and lavage
- fine needle aspiration for micro
What are the two the Prognostic scoring systems used to assess acute pancreatitis?
- Glasgow Criteria
- Ranson’s Criteria
What does the PANCREAS acronym stand for in the Glasgow Criteria?
P -PaO2 A - Age >55 N - Neutrophils C - Calcium R - Renal function E - Enzymes A - Albumin S - Sugar
A score above what is considered severe pancreatitis in both Ranson’s and Glasgow Criterias?
3
What are the 5 factors of Ranson’s Criteria at admission?
- age
- blood glucose
- serum LDH
- AST
- WCC
What is the serum LDH test a measure of?
Lactate dehydrogenase -> an enzyme that when in high accounts is a sign of tissue damage as it has been released from damaged cells
What are the 5 factors of Ranson’s Criteria after 48hr from admission?
- HCT fall
- Blood urea
- serum calcium
- arterial PO2
- base deficit
What is HCT test?
Haematocrit -> expression of total percentage of blood volume that contains red blood cells
List 6 local complications of pancreatitis.
- fluid collection
- pseudocysts
- ascites
- abscess
- necrosis +/- infection
- pleural effusion
List 8 systemic complications of pancreatitis.
- pulmonary failure
- renal failure
- sepsis
- shock
- metabolic acidosis
- hyperglycaemia
- hypocalcaemia
- MODS
What 3 factors are thought to lead to metabolic acidosis in pancreatitis?
- loss of bicarbonate from pancreas
- tissue damage leading to acidification of local tissues
- due to lactic acidosis due to shock, pulmonary failure or sepsis
What is general prognosis of acute pancreatitis?
- Mild to moderate tend to recover, may develop acute pancreatitis.
- severe tend to develop infection/necrosis and mortality is higher
What are the main principles of management in acute pancreatitis?
Conservative
- fluid resus
- electrolyte correction
- oxygen
- antibiotics
- nutrition maybe
- analgesia (opiates e.g. tramadol, fentanyl)
What are some symptoms of pancreatic pseudocysts?
- pain
- nausea
- vomiting
- jaundice
- weight loss
What is treatment for pancreatic pseudocyst?
- endoscopic drainage
- radiological drainage
- surgical drainage
What is treatment for pancreatic abscess?
-CT/US guided retroperitoneal or transperitoneal drainage
How does chronic pancreatitis present?
- epigastric pain
- pain can radiate to back
- pain may be episodic/chronic
- anorexia
- weight loss
What substances can exacerbate chronic pancreatitis?
- meal with high fat content
- alcohol excess
What are some causes of chronic pancreatitis? (AIPATH)
- alcohol
- idiopathic
- PD obstruction
- autoimmune
- tropical countries
- hereditary
What is an acquired anomaly that can cause PD obstruction and then chronic pancreatitis?
Pancreas Divisum
What is pancreas divisum?
Congenital anomaly where a single pancreatic duct does not form but remains as two separate ducts
What is raised in serum and tissue of type 1 autoimmune chronic pancreatitis?
IgG4 levels
What are two differences between most common variant type 1 and second variant type 2 autoimmune chronic pancreatitis?
- Raised IgG4 and autoantibodies found in type 1 and not in type 2
- type 1 can involve extrapancreatic tissue whereas type 2 is usually limited just to pancreas
What extrapancreatic tissues can be involved in type 1 autoimmune chronic pancreatitis?
- biliary tree
- salivary glands
- renal tissue
- thyroid tissue
What deficiencies can lead to chronic pancreatitis in tropical countries?
- zinc
- methionine
- selenium
What hereditary disease can lead to chronic pancreatitis and why?
Cystic fibrosis due to mucous blocking pancreatic secretions
Which type of chronic pancreatitis is not linked to activated trypsin pathways?
Autoimmune pancreatitis
What can increased calcium in pancreas lead to?
Early activation of trypsinogen to trypsin
What 3 factors can cause early trypsinogen activation to trypsin?
- low pH
- active trypsin
- high calcium levels
What are the two main pathophysiological pathways that may be dysfunctional causing chronic pancreatitis due to active trypsin?
- increased/premature activation of trypsin from trypsinogen
- impaired inactivation/clearance of trypsin from pancreas
What are two findings in x-ray/CT scan that confirm diagnosis of chronic pancreatitis?
- pancreatic calcifications
- pancreatic duct dilatation
What investigations are carried out in chronic pancreatitis?
- serum amylase and lipase
- serum IgG4 levels
- faecal elastase
- gene mutation analysis
- US
- CT
- MRI with MRCP
What analgesics are used for pain management in chronic pancreatitis?
- NSAID + opiate
- coeliac axis nerve block
- tricyclic antidepressents
What are 5 signs of pancreatic insufficiency and what is treatment?
- bloating
- pain
- loose, fatty pale stools
- weight loss
- increased stool frequency
- treatment is creon (enzyme replacement therapy)
What surgical treatments can be used in patients with chronic pain in chronic pancreatitis?
endoscopic or surgical:
- removal of intraductal stones
- stenting
- surgical duct drainage procedure and/or partial resection of head of pancreas
What is treatment for malapsorption and steatorrhea in chronic pancreatitis and what might be prescribed in addition?
enzyme supplements sometimes prescribed with acid suppressors (PPI’s/H2 receptor antagonist) to prevent acid denaturation of the enzymes
What is the Pustow Procedure and what is it used to treat?
- Pustow Procedure is a surgery in which the pancreatic duct is cut open and anastomosed to a section of jejunum that has been divided and other end reattached to end of jejunum
- chronic pancreatitis
What is initial treatment for autoimmune pancreatitis and relapse treatment?
- initial: prednisolone
- relapse: azathioprine
What are 8 complications of chronic pancreatitis?
- splenic vein thrombosis
- pseudoaneurysm on splenic artery
- pancreatic cancer
- ascites
- pleural effusion
- pseudocysts
- biliary obstruction
- duodenal obstruction
What can pseudocyst affect?
- occlude bile duct
- occlude gastric outlet
- occlude duodenum
What is management for duodenal obstruction in chronic pancreatitis?
- stent
- bypass
- resection
What is the exocrine type of pancreatic tumour?
adenocarcinoma
List 5 types of endocrine pancreatic tumours.
- gastrinoma
- insulinoma
- glucagonoma
- somatostatinoma
- vipoma (vaso active intestinal polypeptide)
What does a gastrinoma produce and what effect can this have?
- gastrin
- increases stomach acid
- > can lead to PUD
What does insulinoma produce and what effect can this have?
- insulin
- encourages sugar uptake and storage -> can lead to hypoglycaemia
What does glucagonoma produces and what effect can this have?
- glucagon
- increases serum blood sugars
- > can lead to hyperglycaemia
What is the most common form of pancreatic cancer?
Adenocarcinoma (exocrine)
Within which part of the pancreas do most tumours form?
head of pancreas
What does vipoma induce and what are 3 signs of vipoma?
- induces glucogenolysis and hyperglycaemia
- watery diarrhoea
- hypokalaemia
- achlorydia
What are 6 symptoms & signs of pancreatic cancer?
- abdo and back pain
- weight loss
- anorexia
- jaundice
- loose, pale stools
- dark urine
- pruritus
What are risk factors of pancreatic cancer?
- smoking
- diabetes
- chronic pancreatitis
- obesity
What diagnostic tests are used when investigating pancreatic cancer and what can each identify?
- ultrasound -> can identify dilated intrahepatic bile ducts and mass in head of pancreas (not tail or body)
- contrast CT scan (triple phase) -> mass, lymph node involvement, metastasis
- endoscopic ultrasound -> used for investigating small lesions CT might miss
- MRCP/MRI
What is prognosis with pancreatic tumour?
- Mostly in-operable, only approx. 20% operable
- survival rate poor
What 4 aspects are managed and how in in-operable pancreatic cancer?
- pain -> with opiates
- malabsorption -> with enzyme supplementation
- obstructive jaundice -> stents
- duodenal osbtruction -> stents
What are 3 procedures used as treatment in patients with resectable pancreatic tumours?
- Whipple’s procedure
- distal pancreatectomy
- total pancreatectomy
What are 3 procedures used as treatment in patients with non-resectable pancreatic tumours?
- biliary bypass
- double bypass
- gastric bypass
What is the Whipple’s Procedure?
Surgery where duodenum and head of pancreas are cut out, stomach is joined onto the jejenum and end of pancreas is attached onto the jejenum
In which cells does pancreatic adenocarcinoma originate?
ductal epithelium
