97. Pancreas

Question 1

two functional units of the pancreas

Answer 1

98% exocrine (acinar cells/duct system)–>digestive functionEndocrine (islet cells of Langerhans)–>hormonal function

Question 2

islets of langerhans cells

Answer 2

alpha = glucagon (increases glucose)beta = insulin (decreases glucose)delta = somatostatinF or PP = pancreatic polypeptide

Question 3

vascular supply to pancreas

Answer 3

celiac–>hepatic, and splenic artery branches which give pancreas brancheshepatic also gives rise to gastroduodenal artery and then cranial pancreaticoduodenal artery cr mesenteric artery–>caudal pancreaticoduoudenal

Question 4

innervation to the pancreas

Answer 4

enteric nervous system–vagus nerveceliac and superior mesenteric plexusesacinar/islet cells–cholinergicstimulated by PSNSinhibited by SNS

Question 5

major pancreatic duct in dogs

Answer 5

accessory pancreatic duct (duct of Santorini) into the minor duodenal papillapresent in < 20% catsCBD and pancreatic duct (minor contributor–duct of Wirsung) enter major duodenal papilla

Question 6

Major pancreatic duct in cats

Answer 6

pancreatic duct (duct of Wirsung) into the major duodenal papilla combines/fuses w/common bile duct at MDPthis is the only pancreatic duct in 80% of cats

Question 7

insulin functions

Answer 7

B cellsanabolicdecrease blood glucosepromotes IC conversion into glycogencontrols glucose efflux from EC spaces and puts INTO cells

Question 8

glucagon functions

Answer 8

Alpha cellsincrease blood glucosecontrols glucose influx from hepatocytes and takes OUT of cellsmobilizes energy stores by increasing gluconeogenesis, glycogenolysis, lipolysis

Question 9

digestive enzymes from the pancreas exocrine acinar cells

Answer 9

bicarb/water—to neutralize stomach pHintrinsic factors to incr absorption of cobalamin–vit B12 (distal ileum), Zn, colipase C (promotes action of pancreatic lipase)antibacterial factors inhibit bacter prolif in duodenomzymogens (trypsinogen, chymotrypsinogen, proelastases, procarboxypeptidases)–trypsin activated by active peptide enterokinase from duodenal enterocytes, then activates other zymogens into enteropeptidase TABLE 97-1

Question 10

three mechanisms to prevent auto digestion

Answer 10

1. secreted as proenzymes/zymogens (inactive)2. zymogens are packaged as membrane bound granules within rough ER of pancreas3. acinar cells secrete pancreatic trypsin inhibitor to prevent premature activation

Question 11

pancreatic exocrine secretions are under what regulation

Answer 11

stimulation from vagus nerve and food presence in duodenum which stimulates the release of CCK and secretin from duodenal enterocytesCCK–stimulates secretion of digestive enzymessecretin –stimulates secretion of bicarbbiphasic response1. initial spike digestive enzymes 1-2 hr after meal2. second phase rich in bicarb 8-11 hr after meal

Question 12

anesthetic drugs to avoid in pancreatic patients

Answer 12

avoid alpha2 agonist (xylazine, medetomidine)–produce hypoinsulinemia and hyperglycemia–vasoconstriction (poor pancreatic perfusion)

Question 13

two techniques for pancreatic biopsy

Answer 13

most often RIGHT limb pancreas (accessible, distance from duct system, blood supply is not primary source to other organs)–suture fracture technique (guilloteine)–for lesions near extremity of pancreas (may have more inflammation on histopath, but not clinical differences)–blunt dissection and individual ligate/divide–for lesions anywhere is pancreas–laparoscopic biopsy (punch, guilloteine pretied suture, hemoclips, harmonic scalpel, VSD)

Question 14

how much pancreas can be resected so long as there is an intact pancreatic duct

Answer 14

75-90% resection is possible if there is an intact duct remainingthis can be resected without impairment of exocrine and/or endocrine functionregenerative capacity available (production of insulin like growth factor)

Question 15

post op complications requiring life long mgmt following total pancreatecetomy or pancreaticoduodenectomy

Answer 15

tx diabetes mellitustx EPItx gastrointestinal ulcerbiliary diversion (cholecystojejunostomy) with gastroenterostomy (BIllroth 2 or Roux en Y) for pancreaticoduondectomyhigh MM

Question 16

methods for pancreatic drainage in cases of abscesses and/or cysts

Answer 16

1. US guided percutaneous aspiration/drainage2. open abdominal drainage (for severe pancreatitis)3. closed section JP drain4. omentalization

Question 17

define acute, recurrent and chronic pancreatitis

Answer 17

acute–sudden and reversiblerecurrent–repeated episodes, no permanent histological changechronic–continuous, may be subclinical at times, irreversible histologic changes (seen in cats with IBD and cholangitis–triaditis)

Question 18

comparison of SN of diagnostic testing for pancreatitis

Answer 18

most SN–serum cPLI (82% dogs) and semiquantitativeleast SN–serum cTLIcTLI < lipase < ab US < cPLI

Question 19

hallmark clinical sign of pancreatitis

Answer 19

vomiting in dogs!only 40% cats with pancreatitis vomit (most cats were anorexic)

Question 20

minimum data base abnormalities in dogs with pancreatitis

Answer 20

–dehydration (incr HCT/TP)–azotemia (prerenal or AKI)–hyperbilirubinemia (EHBO)–increased liver enzymes (EHBO or severe liver dz)–hypercholesterolemia/hyperTG–hypoCa (saponification of fat)–hyperglycemia (necrotizing pancreatitis–incr cortisol–incr glucagon from pancreas)–incr amylase/lipase (NOT pancreatic specific, can incr with decr GFR)–TLI (SN/SP for EPI but NOT pancreatitis)–cPLI most SN 82% dog 100% cats with sever disease but only 50% in cats with mild dz

Question 21

Thompson et al JVECCS 2009surgical outcome of pancreatitis patients

Answer 21

overall 63% survival80% survival if EHBO with cholecystoenterostomy64% survival if necrosectomy40% survival is pancreatic abscess

Question 22

pancreatic abscess

Answer 22

–most often sterile (take multiple samples from pancreas–15% and ab cavity–60%)–most common sequel following pancreatitissurgery–debride +/- partial pancreatectomy or duodenal R&A +/- cholecystoenterostomy if EHBO severe/irreversible–drainage and/or omentalizationprognosis poor (50% survive range 14-60%)

Question 23

pancreatic pseudocyts

Answer 23

nonepith lined fibrous sac; usually sterilemajority in LEFT limb if small—monitor with serial ab USFNA US guided aspiratesurgery drainage: omentalization, cystoduodenostomy, cystojejunostomy, or complete excisiongood prognosis

Question 24

most common tumor of the exocrine vs endocrine pancreas

Answer 24

exocrine—carcinomaendocrine–insulinoma (beta cell tumor)–60% of which are M carcinoma

Question 25

serum lipas and pancreatic carcinoma

Answer 25

serum lipase&raquo_space;25 times the upper limit is suggestive of pancreatic carcinomaextremely poor px

Question 26

% of dogs with insulinoma have mets at the time of diagnosis

Answer 26

50% (detected via histopath) but suspected to be 100%biopsy LN and liver

Question 27

diagnostic testing for insulinoma

Answer 27

presence of insulin or hyperinsulinemia in presence of hypoglycemia < 60 serum insulin to blood glucose ratio > 30(insulin x 10)/(glucose -30)decreased fructosamine

Question 28

solitary nodule in pancreas is seen in how many insulinoma patients

Answer 28

80% solitary20% multiple nodulesvery few are diffusemost often in right (35%)or left (44%) limbs&raquo_space; pancreatic body (14%)

Question 29

methods to find pancreatic nodule intraoperatively

Answer 29

–intraoperative ultrasonography–sterile methylene blue 3 mg/kg diluted in 250 ml saline given over 30 min (acute renal failure, heinz body anemia)–biopsy left limb (majority of nodules 44%)

Question 30

medical treatment for persistent or recurrent hypoglycemia in cases of insulinoma

Answer 30

–streptozocin: nitrosurea Ab, destroys B cells, nephrotoxic(maintains euglycemia 163 days)–prednisone and diazoxide: inhibits insulin, stimulates hepatic GNG–Octreotide: somatostatin analogue to bind receptors and inhibit insulin synthesis and secretion

Question 31

T/FLonger survival times are seen in dogs treated surgically for insulinoma regardless of mets and complete excision

Answer 31

TRUEsurgery is palliative and reduces tumor burden which improves survival381 days with surgery74 days without surgery(surgery improves medical therapy)

Question 32

MST insulinomas undergoing partial pancreaticetomy

Answer 32

12 monthsmay be less if mets present at time of surgery

Question 33

main negative prognostic indicator for insulinomas

Answer 33

post op hypoglycemia

Question 34

Polton et al 2007 JSAP MST insulinoma with surgery alone and surgery with med rx

Answer 34

surgery alone 785 dayssurgery + rx 1300 dayssmall numbersand may represent earlier diagnosis and intervention

Question 35

Gastrinomas

Answer 35

pancreatic islet cell tumors that secrete excessive gastrin—results in gastric acid hyper secretiontumors can arise in pancreas or duodenummets 70%

Question 36

define Zollinger–Ellison sydrome

Answer 36

NON beta cell islet tumorhypergastrinemiagastrointestinal ulceration