pancreas

• Pancreas


  The name 'pancreas' is derived from the Greek 'pan' (all) and 'kreas' (flesh)
• Pancreas


  • Situated in the retroperitoneum
  • Divided into head (30%), body and tail (70%)
  • Head lies within the curve of the duodenum, overlying the body of the second lumbar vertebra and the vena cava
  • Aorta and the superior mesenteric vessels lie behind the neck of the gland
  • Uncinate process coming off the side of the pancreatic head and passing to the left and behind the superior mesenteric vein
  • Superior mesenteric vein joins the splenic vein to form the portal vein behind the neck of the pancreas
  • Tip of the pancreatic tail extends up to the splenic hilum

  
• Pancreas weight


  Approximately 80 g

  
• Composition of the pancreas


  • Exocrine acinar tissue (80–90%)
  • Endocrine cells (islets of Langerhans)

  
• Exocrine acinar tissue


  • Organised into lobules
  • Main pancreatic duct branches into interlobular and intralobular ducts, ductules and, finally, acini

  
• Endocrine cells (islets of Langerhans)


  • 75% are B cells (producing insulin)
  • 20% are A cells (producing glucagon)
  • Remainder are D cells (producing somatostatin) and a small number of pancreatic polypeptide cells
  • Capillaries draining the islet cells drain into the portal vein, forming a pancreatic portal system

  
• Approximately 10% of patients will have a significant flow from the main duct through the accessory papilla
• Anatomy of the main duodenal papilla (ampulla of Vater)


  • Outlet of each duct is protected by a complex sphincter mechanism (sphincter of Oddi)

  
• Anomalies of the pancreas


  • Aplasia
  • Hypoplasia
  • Hyperplasia
  • Hypertrophy
  • Dysplasia
  • Variations and anomalies of the ducts
  • Pancreas divisum
  • Rotational anomalies
  • Annular pancreasa
  • Pancreatic gall bladder
  • Polycystic disease
  • Congenital pancreatic cysts
  • Ectopic pancreatic tissue, accessory pancreasa
  • Vascular anomalies
  • Choledochal cysts
  • Horseshoe pancreas

  
• Cystic fibrosis


  • Inherited as autosomal recessive condition
  • Occurs most frequently among Caucasians, in whom it is the most common inherited disorder (incidence of 1:2000 live births in the UK)
  • Mutation in the CFTR (cystic fibrosis transmembrane conductance regulator) gene on chromosome 7
  • CFTR gene creates a cell membrane protein that helps to control the movement of chloride across the cell membrane
• Cystic fibrosis


  • Multisystem disorder of exocrine glands that affects the lungs, intestines, pancreas and liver
  • Characterised by elevated sodium and chloride ion concentrations in sweat
  • Organ damage due to blockage of narrow passages by thickened secretions
  • Chronic pulmonary disease arises from plugging of bronchi and bronchioles
  • Meconium may set in a sticky mass and produce intestinal obstruction (meconium ileus)
  • Secretions precipitate in the lumen of the pancreatic duct causing blockage, which results in duct ectasia and fatty replacement of exocrine acinar tissue
  • Pancreatic exocrine insufficiency leads to fat malabsorption
  • Steatorrhoea is usually present from birth
  • Liver may become cirrhotic as a result of bile duct plugging
  • Infertility is common

  
• Pancreas divisum


  • Occurs when the embryological ventral and dorsal parts of the pancreas fail to fuse
  • The dorsal pancreatic duct drains through the accessory papilla

  
• The earliest clinical signs of cystic fibrosis are poor growth, poor appetite, rancid greasy stools, abdominal distension, chronic respiratory disease and finger clubbing

  
• The diagnosis of cystic fibrosis can be made by genetic testing (which may be part of prenatal or newborn screening) or sweat test
• Treatment of cystic fibrosis


  1. Control of the secondary consequences of the disease

  2. Preserve pulmonary function with aggressive physiotherapy and antibiotics

  3. Treat malabsorption by administration of oral pancreatic enzyme preparations

  4. Diet should be low in fat but contain added salt to replace the high losses in the sweat
• Pancreas divisum occurs when the embryological ventral and dorsal parts of the pancreas fail to fuse

  
• The dorsal pancreatic duct drains through the accessory papilla in pancreas divisum

  
• Cystic fibrosis


  Absence of the vas deferens in men and thick cervical mucus in women
• Earliest clinical signs of cystic fibrosis


  • Poor growth, poor appetite, rancid greasy stools, abdominal distension, chronic respiratory disease and finger clubbing

  
• Diagnosis of cystic fibrosis


  1. Genetic testing (which may be part of prenatal or newborn screening)

  2. Sweat test (Levels of sodium and chloride ions in the sweat above 90 mmol/L confirm the diagnosis)

  
• Treatment of cystic fibrosis


  1. Control of the secondary consequences of the disease

  2. Preserve pulmonary function with aggressive physiotherapy and antibiotics

  3. Treat malabsorption with oral pancreatic enzyme preparations

  4. Low fat diet with added salt to replace high losses in sweat
• Pancreas divisum


  Embryological ventral and dorsal parts of the pancreas fail to fuse, with the dorsal pancreatic duct becoming the main pancreatic duct

  
• Incidence of pancreas divisum ranges from 5% in autopsy series to 10% in some ERCP and MRCP series

  
• Pancreas divisum in asymptomatic people


  Does not warrant any intervention

  
• Incidence of pancreas divisum ranges from 25–50% in patients with recurrent acute pancreatitis, chronic pancreatitis and pancreatic pain

  
• Diagnosis of pancreas divisum

  MRCP, EUS or ERCP, augmented by injection of secretin if necessary

  
• Treatment of pancreas divisum

  1. Endoscopic sphincterotomy and stenting of the minor papilla

  2. Surgical intervention (sphincteroplasty, pancreatojejunostomy or resection of the pancreatic head)

  
• Annular pancreas


  Failure of complete rotation of the ventral pancreatic bud during development, so that a ring of pancreatic tissue surrounds the second or third part of the duodenum

  
• Annular pancreas is most often seen in association with congenital duodenal stenosis or atresia and is therefore more prevalent in children with Down syndrome

  
• Treatment of annular pancreas


  Bypass (duodenoduodenostomy)

  
• Ectopic pancreas


  Islands of ectopic pancreatic tissue can be found in various locations in the body

  
• Congenital cystic disease of the pancreas

  Sometimes accompanies congenital disease of the kidneys and liver, and occurs as part of the von Hippel–Lindau syndrome

  
• Pancreatic injuries from external trauma

  • Contusion or laceration of the parenchyma without duct disruption
  • Major parenchymal destruction with duct disruption (sometimes complete transection)
  • Rarely, massive destruction of the pancreatic head

  
• Most important factor determining treatment of pancreatic trauma

  Whether the pancreatic duct has been disrupted

  
• Presentation of blunt pancreatic trauma


  Epigastric pain, rise in serum amylase, CT scan to delineate damage

  
• Management of blunt pancreatic trauma


  1. Conservative management if haemodynamically stable, without peritonitis

  2. Operation indicated if there is disruption of the main pancreatic duct

  
• Management of penetrating pancreatic trauma


  Urgent surgical exploration, distal pancreatectomy if transection in body or tail, haemostasis and drainage for head injury, pancreatoduodenectomy for severe head and duodenal injury

  
• External injury to the pancreas


  • Other organs are likely to be injured
  • It is important to ascertain if the pancreatic duct has been disrupted
  • CT and ERCP are the most useful tests
  • Surgery is indicated if the main pancreatic duct is disrupted

  
• Iatrogenic injury to the pancreas


  • Injury to the tail during splenectomy
  • Injury to the head and accessory duct during Billroth II gastrectomy
  • Enucleation of islet cell tumours
  • Duodenal or ampullary bleeding following sphincterotomy

  
• Pancreatic fistula


  Follows operative trauma to the gland or complication of pancreatitis, important to define site and epithelial structure it communicates with