Pancreas Flashcards
Head blood supply
superior (off GDA) and inferior (off SMA) pancreaticoduodenal arteries (ant/post branches)
Body blood supply
great, inferior, and caudal pancreatic artery (off splenic artery)
Tail blood supply
splenic, gastroepiploic and dorsal pancreatic arteries
Located where
retroperitoneum
SMA and SMV
lie behind neck of pancreas
Venous drainage
into portal system
Portal vein
forms behind neck (SMV and splenic vein)
Ductal cells
have carbonic anhydrase and secrete HCO3- ; increase flow leads to increase bicarb and decrease chloride
Acinar cells
secrete chloride and digestive enzymes
Ventral pancreatic bud
connected to duct of wirsung; migrates posteriorly, to the right and clockwise and fuse with dorsal bud; forms uncinate and inferior portion of head
Dorsal pancreatic bud
body, tail, and superior aspect of pancreatic head; duct of santorini
Duct of santorini
small accessory pancreatic duct that drains directly into duodenum
Duct of wirsung
major pancreatic duct that merges with CBD before entering duodenum
Exocrine function
amylase, lipase, trypsinogen, chymotrypsinogen, carboxypeptidase; bicarb
Amylase
only pancreatic enzyme secreted in active form; hydrolyzes alpha 1-4 linkages of glucose chains
Enterokinase
released by duodenum; activates trypsinogen to trypsin; trypsin activates other pancreatic enzymes
Secretin
released from cells in duodenum; increase bicarb
CCK
released from cells in duodenum; increase enzymes
Acetylcholine
increase bicarb and enzymes
somatostatin and glucagon
decrease exocrine function
Endocrine function
glucagon (alpha cells); insulin (beta cells, center of islets); somatostatin (delta cells); pancreatic polypeptide (PP or F cells)
Islet cells
also prodce VIP, serotonin, neuropeptide Y, gastrin releasing peptide; receive majority of blood supply
Annular Pancreas
2nd portion of duodenum trapped in pancreatic band; can see double bubble on abdominal xray; assoc with down syndrome; forms from ventral pancreatic bud from failure of clockwise rotation; tx: duodenojejunostomy or duodenoduodenostomy and sphincteroplasty; pancreas not resected
Pancreas divisum
failed fusion of pancreatic ducts; can result in pancreatitis from duct of santorini (accessory duct) stenosis; most are asymptomatic; some get pancreatitis; DX: ercp, minor papilla will show long and large duct of Santorini, major papilla will show short duct of Wirsung; tx: sphincteroplasty and stent placement if symptomatic, some may need pancreaticojejunostomy
Heterotopic pancreas
most commonly found in duodenum; usually asymptomatic; surgical resection if symptomatic
Pancreatic pseudocysts
nonepithelialized sac; expectant management up to 3 months, allows pseudocyst to mature; only need to treat pts with continued symptoms or pseudocysts that are growing; need MRCP / ERCP to check for duct involvemnt; if duct involved need cystogastrostomy; if duct not involved can do perc drainage
Puestow procedure
chronic pancreatitis; pancreaticojejunostomy for ducts > 8mm; open along main pancreatic duct
Pancreatic adenocarcinoma
tobacco #1 risk factor; lymphatic spread first; 70% in head; 50% invade portal vein, SMV, or retroperitoneum at time of dx; mets to peritoneum, omentum, liver, celiac, SMA nodes unresectable disease; pts with resectable disease do not need biopsy; if appears to have mets then biopsy
Whipple
pancreaticoduodenectomy; delayed gastric emptying #1 complication
Intraductal Papillary Mucinous Neoplasm
6th-7th decade of life; side branch, main duct, mixed type; tx: partial pancreatectomy for main duct, symptomatic, large branch type > 3c, or invasive component; cyst fluid: mucin stain positive; high amylase; high CEA
Mucin cystic neoplasm
cyst fluid: mucin stain positive, low amylase, high CEA
Serous cystic neoplasm
cyst fluid: mucin stain negative, low amylase, low CEA
Pseudocyst
cyst fluid: mucin stain negative; high amylase; low CEA
Pancreatic trauma
Grade I:
hematoma - minor contusion without ductal injury
laceration - superficial lac w/o ductal injury
Grade II:
hematoma - major contusion w/o ductal injury
laceration - major lac w/o ductal injury
Grade III:
laceration - distal transection or parenchymal injury with ductal injury
Grade IV:
laceration - proximal transection or parenchymal injury involving the ampulla
Grade V:
laceration - massive disruption of pancreatic head
Nonfunctional Endocrine Tumors
1/3 pancreatic endocrine tumors; 90% malignant; sxs: pain, weight loss, jaundice; indolent course; tx: resection unless mets; 5FU and streptozocin may be effective; 50% 5 year survival after resection
Insulinoma
- most common islet cell tumor and functional neoplasm of pancreas
- 90% benign; evenly distributed; 10% assoc with MEN I
- sxs: whipples triad
1. fasting hypoglycemia
2. sxs of hypoglycemia (palpitations, tachycardia, sweating, blurry vision, fatigue, seizures)
3. relief with glucose - Dx –> insulin:glucose ratio > 0.4 after fast; increase c-peptide and proinsulin
- Tx: enucleate < 2cm; formal resection > 2cm; mets streptozocin, octreotide, 5FU
Gastrinoma
- most common islet cell tumor (fxt’l tumor) in MEN-I
- 50% malignant / 50% multiple
- 75% sporadic / 25% MEN-I
- majority in gastrinoma triangle (CBD, neck of pancreas, 3rd portion of duodenum)
- Sx: refractory ulcer disease, abd pain, diarrhea
- Dx: gastrin > 200, > 1,000 diagnositc; secretin stim test (gastrin > 200, normal pts decrease gastrin); octreotide scan (somatostatin receptor scintigraphy) best study to localize tumor
- Tx: enucleation < 2cm; formal resection > 2cm; excise suspicious nodes; can’t find tumor perform duodenostomy, look inside duodenum; duodenal tumor resect with primary closure (whipple maybe); debulking can improve
Somatostatinoma
- very rare; most malignant / most in head
- Sx: DM, gallstones, steatorrhea, hypochlorhydria
- Dx: fasting somatostatin level > 100
- tx: perofrm chole with resection; debulk hepatic mets
Glucagonoma
- most malignant; distal panc
- Sx: DM, stomatitis, dermatitis (necrolytic migratory erythema), weight loss)
- Dx: high fasting glucagon level; biopsy skin lesion
- Tx: resection (usually distal panc); octreotide useful in controlling symptoms (hyperglycemia, dermatitis); zinc, amino acids or fatty acids for skin rash
VIPOMA
- verner-morrison syndrome
- most malignant; most distal; 10% extrapancreatic (RP, thorax)
- Sxs: watery diarrhea, hypokalemia, achlorhydria (WDHA); decrease K+ from diarrhea (lethargy, muscle weakness, nausea); metabolic acidosis d/t loss of bicarb in diarrhea
- Dx: exclude other causes of diarrhea; increase VIP level
- Tx: pre op electrolyte correction; distal panc; octreotide as adjunct
Functional Endocrine Pancreatic Tumors
Insulinoma Gastrinoma Somatostatinoma Glucagonoma VIPoma
