NMS Pancreas 1 (includes gallbladder) Flashcards
annular pancreas
usually presents in infancy w duodenal obstruction (postprandial vomiting). caused by malrotation of ventral pancreas –> ring of pancreatic tissue around second portion of duodenum
pancreatitis and peptic ulcers also may result
Pancreas divisum
due to failure of ventral and dorsal ducts to fuse, majority of pancreatic drainage is accomplished via accessory papilla and duct of Santorini.
–> most common congenital anomaly of pancreas (5% of population) but usually asymptomatic.
rarely chronic pain and recurrent pancreatitis result from inadequate drainage
heterotopic pancreas
pancreatic tissue in an abnormal location (stomach, duodenum, Meckel’s diverticulum)
why does resection of head of pancreas require resection of duodenum
bc they have shared blood supply (gastroduodenal –> pancreaticoduodenal artery)
pancreatic ducts
- duct of wirsung is main duct; runs entire length of pancreas. it joins common bile duct and empties into 2nd part of duodenum at ampulla of vater
- duct of santorini (small duct) is an accessory duct often joining the duodenum more proximally than ampulla of vater
blood supply of pancreas
- head: anterior and posterior superior pancreaticoduodenal arteries = branches of gastroduodenal artery;
anterior and posterior inferior pancreaticoduodenal arteries=branches of SMA - NECK, BODY, TAIL: splenic artery and branches (dorsal pancreatic artery)
exocrine physiology of pancreas
secretion of 1-2L/d of clear, isosmotic alkaline fluid containing digestive enzymes.
exocrine pancreas makes up 85% of pancreatic volume;
endocrine pancreas accounts for only 2%, with the rest composed of extracellular matrix and vessels or ducts
what kind of block can be done for pain control in pancreatic dz
celiac plexus block
secretin
most potent endogenous stimulant for bicarbonate secretion
endocrine function of pancreas
Islets of Langerhans make up 2% of pancreas by weigh:
1) insulin: from beta cells in islets of Langerhans (glucose absorption and storage);
2) glucagon: from islet alpha cells (glycogenolysis and release of glucose);
3) somatostatin: from islet delta cells (generally –> inhibitory function of GI tract)
uses of somatostatin
- treat symptoms of neuroendocrine tumors (islet cell, carcinoid, gastrinoma, VIPoma, and acromegaly)
- convert high output fistulae to low output fistula (bc of its antimotility and antisecretory effects)
acute pancreatitis
inflammation of pancreas due to parenchymal autodigestion by proteolytic enzymes
CAUSES: 1) alcohol abuse (40-50%); 2) gallstones (40%)
Less common causes of acute pancreatitis
- hyperlipidemia
- hypercalcemia: 2/2 hyper PTH
- trauma
- post op and post ERCP
- pancreatic duct obstruction (tumor, pancreatic divisum)
- vasculitis
- scorpion venom
- viral infections
- drugs (azathioprine, INH, cimetidine)
signs and symptoms of acute pancreatitis
- severe, constant epigastric pain radiating to the back. pain may be improved by sitting forward or standing
- nausea/vomiting
- low grade fever, tachypnea, tachycardia, upper abdominal tenderness with guarding but no rebound. bowel sounds may be absent due to adynamic ileus.
signs of hypovolemic shock may also be present due to massive retroperitoneal fluid sequestration and dehydration
cullens sign
bluish discoloration of periumbilicus
hemorrhagic pancreatitis
grey-turners sign
bluish discoloration of flank
hemorrhagic pancreatitis
fox’s sign
bluish discoloration of inguinal ligament
hemorrhagic pancreatitis
cullens, grey turners, fox’s sign
indicative of severe, hemorrhagic pancreatitis
MEDVIPS: drug-induced pancreatitis
- methyldopa/metronidazole
- estrogen
- didanosine (inhibits HIV DNA polymerase reverse transcriptase)
- valproate
- INH
- pentamidine
- sulfonamides
elevate lipase
only found in gastric and intestinal mucosa and liver, in addition to pancreas, so is more specific for pancreatitis than amylase
elevated amylase
also found in salivary glands, small bowel, ovaries, skeletal muscle (+pancreas) so not specific marker for pancreatitis
Ranson’s criteria : on admission
- age>55
- blood glucose>200
- AST>250
- LDH> 350
- WBC >16k
Ranson’s criteria: after 48 h
- base deficit >4
- increase in BUN >5
- fluid deficit > 6L
- Calcium 10%
- PO2 < 60 mm Hg
diagnostic choice for acute pancreatitis
CT scan: 90% sensitive, 100% specific.
demonstrates pseudocysts, phlegmon, abscess, or pancreatic necrosis
causes of elevated amylase levels
high amylase levels are seen in intestinal disease, perforated ulcer, ruptured ectopic pregnancy, salpingitis, salivary gland disorders, renal failure, and diabetic ketoacidosis
treatment of acute pancreatitis
- aggressive hydration with electrolyte monitoring to maintain adequate intravascular volume
- NG tube if vomiting
- antibiotics if infection identified
- NPO with nutritional support via post-pyloric feeding or TPN
- avoid morphine-possible spasm of sphincter of Oddi (use IV fentanyl or hydromorphone; meperidine favored over morphine)
- surgery indicated for either infected necrosis of pancreas or correction of associated biliary tract dz
chronic pancreatitis
chronic inflammation or recurrent acute pancreatitis causes irreversible parenchymal fibrosis, destruction, and calcification –> loss of endocrine and exocrine function
causes of chronic pancreatitis
- EtOH abuse (70%)
- idiopathic (20%)
- other (10%): hyper PTH, HLD, congenital pancreatic abnormalities, hereditary, obstruction
signs and symptoms of chronic pancreatitis
- recurrent or constant epigastric/back pain
- malabsorption/malnutrition (exocrine dysfunction)
- steatorrhea (exocrine dysfunction-fat soluble vitamin deficiency (ADEK)
- Type 1 diabetes mellitus
- polyuria
diagnosis of chronic pancreatitis
- pancreatic calcifications
- chain of lakes pattern on ERCP with ductal irregularities/dilatation/stenosis
- pseudocysts with gland enlargement/atrophy, masses
Pseudocysts
nonepithelialized, encapsulated pancreatic fluid collections. up to 30% of pseudocysts resolve on their own with bowel rest (TPN and NPO). if after 6 wks they have not resolved and are > 6 cm in size, internal drainage of the mature cysts indicated via cyst gastrostomy or Roux-en-Y cyst jejunostomy.
pancreatic adenocarcinoma
- originate in exocrine pancreas (ductal cells)
- 2/3 occur in head of pancreas
risk factors:
- male
- african-american
- tobacco user
Courvoisier’s sign
jaundice with palpable gallbladder that is nontender
signs and symptoms of pancreatic adenocarcinoma
- weight loss
- (painless) jaundice
- posterior epigastric pain radiating to the back
- migratory thrombophlebitis (Trousseau’s syndrome esp seen in tumors of body or tail)
diagnosis of pancreatic adenocarcinoma
- elevated CEA or CA19-9
- CT scan is study of choice
- PTC and ERCP useful in periampullary lesions
treatment of pancreatic adenocarcinoma
- tumors of head: Whipple procedure (pancreaticoduodenectomy)
- tumors of body/tail: distal near-total pancreatectomy
- if unresectable 2/2 liver or peritoneal mets, nodal mets beyond zone of resection, or tumor invasion of SMA, palliative procedures considered
Whipple procedure
removal of gallbladder, common bile duct, antrum of stomach, duodenum, proximal jejunum and head of pancreas (en bloc);
reconstruction with pancreaticojejunostomy , choledochojejunostomy, and gastrojejunostomy
prognosis for adenocarcinoma
median survival for patients who undergo successful resection is approximately 12-19 months, with 5y survival rate of 15-20%
pancreatic cystadenocarcinoma
- commonly seen in females 40-60y
- occurs in body/tail
- accounts for <2% of all pancreatic exocrine tumors
- prognosis better than adenocarcinoma
- TREATMENT: distal/total pancreatectomy
pancreatic cystadenoma
- seen in older/middle aged women
two types:
a. serious: benign
b. mucinous: generally benign, but potential to be malignant - treatment: surgical resection
insulinoma
beta cell neoplasm with overproduction of insulin
- MC islet cell tumor
- 90% are benign
- most are solitary lesions with even distribution in head/body/tail of pancreas
- if associated with MEN I (<10% of all cases), then multiple insulinomas may be present
diagnosis of insulinoma
- fasting serum insulin level >10 uU/mL [nL is 0.3
3. prosinulin or C-peptide levels should be measured to rule out surreptitious exogenous insulin administration
treatment for insulinoma
- surgical enucleation/resection usually curative
2. diazoxide can improve hypoglycemic symptoms by inhibiting pancreatic insulin release
what is Whipple’s triad
characterizes insulinoma
- symptoms of hypoglycemia with fasting
- fasting glucose <50 mg/dL
- relief of symptoms after eating (glucose)
gastrinoma
neoplasm associated with overproduction of gastrin; aka Zollinger-Ellison syndrome
epidemiology of gastrinomas
- second most common islet cell tumor
- 90% are located in gastrinoma triangle bordered by junction of second and third part of duodenum, cystic duct, and SMA under the neck of the pancreas
- 25% of gastrinomas are associated with MEN-1
signs and symptoms of gastrinomas
- signs mimicking peptic ulcer dz
- epigastric pain most prominent after eating
- profuse, watery diarrhea
diagnosis of gastrinoma
- fasting serum gastrin level > 500 pg/mL [nl: <100 pg/mL]
- secretin stimulation test will cause paradoxical increase in gastrin in patients with Zollinger-Ellison syndrome
- ulcers in unusual locations (ie, 3rd part of duodenum or jejunum) is highly suggestive
- octreotide scan to localize tumor
treatment of gastrinoma
- PPI
- surgical resection
- chemotherapy
VIPoma
overproduction of VIP; aka Verner Morrison syndrome or WDHA syndrome (Watery Diarrhea, Hypokalemia, Achlorhydria);
most are malignant and majority have metastasized to lymph nodes and the liver at time of dx
10% extrapancreatic
signs and symptoms of VIPoma
- severe, watery diarrhea
2. signs of hypokalemia-palpitations/arrhythmias, muscle fasciculations/tetany, paresthesias
treatment of VIPoma
fasting serum VIP>800 pg/mL (normal<200 pg/mL) with exclusion of other causes of diarrhea
glucagonoma
rare alpha cell neoplasm resulting in overproduction of glucagon
signs and symptoms of glucagonoma
- mild diabetes (hyperglycemia)
- anemia
- mucositis
- weight loss due to low amino acid levels
- severe dermatitis: often a red psoriatic like rash with serpiginous borders over trunk and lower limbs
skin condition associated with glucagonoma
necrolytic migratory erythema
diagnosis of glucagonoma
- fasting serum level glucagon > 1000 pg/mL
2. skin bx to confirm presence of necrolytic migratory erythema
common bile duct forms in which pancreatic bud
ventral
which pancreatic bud migrates to fuse with other
ventral
what does ventral pancreatic bud form in adult
uncinate process and inferior aspect of pancreatic head
what does dorsal bud form
superior aspect of head, body, tail
from which pancreatic bud does small accessory pancreatic duct of santorini form
from dorsal bud
main duct of wirsung forms from entire ventral pancreatic duct which fuses with …
distal pancreatic duct of dorsal bud
what abnormality arises if ventral pancreatic bud migrates posteriorly AND anteriorly to fuse with dorsal pancreatic bud
annular pancreas
name parts of pancreas
head, neck, body, tail
on what structure does pancreatic head rest
IVC, renal vessels
on what structure does uncinate process rest
aorta
what lies behind pancreatic neck
SMA
how is blood supplied to head of pancreas from celiac axis
gastroduodenal artery branches into SUPERIOR posterior and anterior pancreaticoduodenal artery
how is blood supplied to pancreatic head from celiac axis (2)
SMA branches into INFERIOR posterior and anterior branches of pancreaticoduodenal
which arteries supply body and tail of pancreas
splenic –> dorsal pancreatic –> joining branch from SMA –> forming inferior pancreatic
also multiple branches from splenic + inferior pancreatic arteries supply tail
into which veins do pancreatic veins drain
splenic vein into portal vein
which nodal groups drain pancreas
head: subpyloric, portal, mesocholic, aortocaval
body and tail: retroperitoneal in splenic hilum
to mesocolic, mesenteric, aortocaval
what do islet cells make
insulin (beta)
glucagon (alpha)
somatostatin (delta)
type of cells in exocrine pancreas
acinar, centroacinar, intercalated ductal, ductal
pH of pancreatic secretions
8
enzymes from pancreas
peptidases, trypsin, chymotrypsin, elastase, kallikrein, carboxypeptidase A and B
what stimulates exocrine secretion
bicarb: vagal efferents and secretin
enzymes: cholecystokinin and acetylcholine
what GI hormone is structurally similar to CCK
gastrin
what activates peptidases
enterokinase
what % acute pancreatitis is idiopathic
10%
metabolic causes of pancreatitis
hyperlipidemia, hypercalcemia
other surgical dzs causing pancreatitis
perforating peptic ulcer, Crohn dz of duodenum
diagnostic GI test that can cause pancreatitis
ERCP
arachnid bite that can cause pancreatitis
scorpion
worms that can cause obstructive pancreatitis
Ascaris, clonorchis sinensis
tests for diagnosing acute pancreatitis
amylase in serum, peritoneal fluid and urinary amylase
serum lipase, WBC, total bilirubin, LFT
AXR, US, CT
what is a sentinel loop
adynamic, dilated loop of small bowel associated with a focal area of inflammation initially described in relation to pancreatitis-associated ileus
when can patients with pancreatitis be fed
NOT early; this causes reactivation
but i saw that early enteral feeds is good…what??
should abx be used in treatment of acute pancreatitis
yes, necrotizing pancreatitis
this is controversial i think?
which abx to use for necrotizing pancreatitis
imipenem/cilastatin
how many patients with acute pancreatitis need surgery
10%
does early use of minidose heparin prevent intravascular thrombosis during acute pancreatitis or alter the course of pancreatitis
prob not
does peritoneal lavage alter clinical course of severe or necrotizing pancreatitis
controversial
recent study showed that patients with 5 or more of Ranson’s criteria had reduced sepsis/death (with peritoneal lavage)
how should patients with severe pancreatitis be nourished
TPN;
but when peristalsis returns, nasoenteric or enteric feeding tubes (early enteral feeds?) may offer better nutrition without worsening pancreatitis (beyond ligament of Treitz)