Fiser Chapter 33. PANCREAS Flashcards
Blood supply of pancreas
Superior and inferior pancreaticoduodenal arteries (superior off GDA, inferior off SMA); splenic artery, gastroepiploic and great/inferior/caudal/dorsal pancreatic arteries
Pancreatic venous drainage
Portal system. PV is behind neck of pancreas (where SMV and splenic vein meet)
Pancreatic lymphatics
Celiac and SMA nodes
Pancreatic ductal cells
Secrete HCO3- solution (have carbonic anhydrase)
Pancreatic acinar cells
Secrete digestive enzymes
Pancreatic exocrine function
Amylase (only pancreatic enzyme secreted in active form; hydrolyzes alpha 1-4 linkages of glucose chains) Lipase Trypsinogen Chymotrypsinogen Carboxypeptidase HCO3-
Pancreatic endocrine function
Alpha cells: glucagon
Beta cells (at center of islets): insulin
Delta cells: somatostatin
PP or F cells: pancreatic polypeptide
Islet cells: also produce VIP and serotonin
Enterokinase
Released by duodenum, activates trypsinogen to trypsin
Trypsin activates other pancreatic enzymes including trypsinogen
Hormonal control of pancreatic excretion
Secretin increases HCO3- mostly (from ductal cells)
CCK increases pancreatic enzymes mostly (from acinar cells)
Acetylcholine increases HCO- and enzymes
Somatostatin and glucagons decrease exocrine function
CCK and secretin: most released by cells in duodenum
Ventral and dorsal pancreatic buds
Ventral: duct of Wirsung (major duct that merges with CBD before entering duo), migrates posteriorly to the R and clockwise to fuse with dorsal bud; forms uncinated and inferior portion of head
Ductal: body, tail, and superior aspect of pancreatic head; has duct of Santorini (small accessory duct that drains directly into duo)
Double bubble
Duodenal obstruction, can be from annular pancreas causing 2nd portion of duo to be trapped in pancreatic band
Annular pancreas is associated with Down syndrome; forms from ventral pancreatic bud from failure of clockwise rotation
Tx of annular pancreas is duodenojejunostomy or duodenoduodenostomy; possible sphincteroplasty; pancreas NOT resected
Pancreatitis from duct of Santorini stenosis
Can be from pancreas divisum (failed fusion of pancreatic ducts)
Most with pancreas divisum are asymptomatic, some get pancreatitis
Dx: ERCP shows minor papilla with long and large duct of Santorini; major papilla with short duct of Wirsung
Tx: ERCP with sphincteroplasty; open sphincteroplasty if fails
Most common location of heterotopic pancreas
Duodenum. Usually asymptomatic. Surgical resection if symptomatic
MCC acute pancreatitis
Gallstones and EtOH
Other: ERCP, trauma, HLD, hyperCa, viral infection, meds (azathioprine, furosemide, steroids, cimetidine)
Gallstone pancreatitis mech
Can obstruct ampulla of Vater, causing impaired extrusion of zymogen granules and activation of degradation enzymes -> pancreatic autodigestion
EtOH pancreatitis mech
Auto-activation of enzymes while still in pancreas
Abdominal pain radiating to back, nausea, vomiting, anorexia; possibly jaundice, L effusion, ascites, or sentinel loop
Acute pancreatitis
Mortality rate of acute pancreatitis
10%
50% if hemorrhagic pancreatitis
Pancreatitis without obvious cause
Malignancy?
Ranson’s criteria (on admit and at 48 hr)
Admit: Age > 55, wbc > 16, glucose < 200, AST < 250, LDH > 350
28hr: Hct decreased by 10%, BUN increased by 5, Ca < 8, PaO2 < 60, base deficit > 4, fluid sequestration > 6 L
If 8 criteria met, mortality near 100%
Necrotic pancreas on abdominal CT
will NOT uptake contrst
Acute pancreatitis tx
NPO, fluid resuscitation
ERCP if gallstone panc and retained CBD stones, with sphincterotomy and stone extraction
Abx for stones, severe pancreatitis, failure to improve (?)
Avoid morphine
If gallstone panc, chole same admission
Flank ecchymosis
Grey-Turner sign (bleeding)
Periumbilical ecchymosis
Cullen’s sign (bleeding)
Inguinal ecchymosis
Fox’s sign (bleeding)
Pancreatic necrosis
15% get it
If sterile, no abx
If infected (fever, sepsis, positive blood cultures): may need to sample with CT-guided aspiration to get diagnosis; then treatment is surgical debridement
Pancreatic abscess tx
Surgical debridement
Perc drainage of panc abscess or necrosis is generally NOT effective
Gas in necrotic pancreas
infected necrosis or abscess, need open debridement
Leading cause of death with pancreatitis
Infection (usually GNRs)
Most important risk factor for necrotizing pancreatitis
Obesity
ARDS in pancreatitis is from what?
Release of phospholipases
Coagulopathy in pancreatitis is from what?
Related to release of proteases
Pancreatic fat necrosis is related to what?
Release of phospholipases
Mild increase in amylase and lipase causes
Pancreatitis, cholecystitis, perforated ulcer, sialoadenitis, SBO, and intestinal infarction
Pancreatic pseudocyst
MCC chronic pancreatitis (otherwise need to check for ca e.g. mucinous cystadenocarcinoma); most often in head; non-epithelialized sac
Most resolve spontaneously (especially if <5cm)
Pancreatic pseudocyst tx
Expectant mgt for 3 months, allows pseudocyst to mature if cystogastrostomy required. May need TPN if unable to eat. Surgery only for continued symptoms (cystogastrostomy, open or percutaneous) or growing pseudocysts (resection to r/o ca)
Pseudocyst complications
Infection, PVT, splenic vein thrombosis
Incidental pseudocyst, no hx of pancreatitis
Resect (worry about intraductal papillary-mucinous neoplasms or mucinous cystadenocarcinoma) unless cst is purely serous and non-complex
Non-complex, purely serous cystadenoma
Extremely low malignancy risk (<1%), just follow
Pancreatic fistula tx
Most close spontaneously (especially if low output <200 cc/day)
Remove drain when drain amylase < serum amylase
Drain, NPO, TPN, octreotide
If failure to resolve with medical mgt, can try: ERCP, sphincterotomy, pancreatic stent placement
Pancreatitis-associated effusion or ascites causes
Retroperitoneal leakage of pancreatic fluid from pancreatic duct of pseudocyst (NOT a fistula)
Most close on their own
Tx: thoracentesis or paracentesis, NPO, TPN, octreotide
Chronic pancreatitis
Irreversible parenchymal fibrosis
MCC: EtOH, then idiopathic
Most common problem with chronic pancreatitis
Pain
Can also have anorexia, weight loss, malabsorption (fat-soluble vitamins), steatorrhea, recurrent acute panc
Endocrine and exocrine function in chronic panc
Endocrine usually preserved (islet cells)
CT with shrunken pancreas with calcifications
Chronic panc
US of chronic panc
Panc ducts > 4mm, cysts, atrophy
Dx of chronic panc
ERCP very sensitive
Advanced disease shows chain of lakes -> alternating segments of dilation and stenosis in PD
Tx of chronic panc
Supportive, including pain control and pancrelipase
Surgery for pain that interferes with QoL, nutrition abnormalities, addiction to narcs, failure to r/o Ca, and biliary obstruction
Surgery for chronic panc
- Peustow
- Distal pancreatic resection
- Whipple
- Begre-Frey
- Bilateral thoracoscopic splanchnicectomy or celiac ganglionectomy for pain control
- Hepaticojejunostomy or choledochojejunostomy for CBD stricture with pain, jaundice, progressive cirrhosis, or cholangitis (first make sure its not cancer)
Peustow
pancreaticojejunostomy, for enlarge ducts > 8mm (most patients improve): open along main PD and dran into jejunum
Distal pancreatic resection
For normal or small ducts and only distal portion of gland affected
Whipple for chronic panc
For normal or small ducts with isolated pancreatic head disease
Beger-Frey
Duodenal preserving head core-out: for normal or small ducts with isolated pancreatic head enlargement
Most common cause of splenic vein thrombosis
Chronic pancreatitis
Tx: splenectomy for isolated bleeding gastric varices
Pancreatic insufficiency
Usually due to long-standing pancreatitis or after total pancreatectomy (over 90% of function must be lost)
Generally refers to exocrine function
Symptoms: malabsorption and steatorrhea
Dx: Fecal fat testing
Tx: High carb, high protein, low fat diet; and pancrease
Jaundice workup
Ultrasound
If CBD stones but no mass -> ERCP to extract stones
No stones or mass -> MRCP
Positive mass -> MRCP
Pancreas cancer survival
20% at 5 years with resection
Risk factors for panc ca
Tobacco #1
Serum marker for panc ca
CA19-9
Most common mutation in panc cancer
p16 (in 95%): tumor suppressor, binds cyclin complexes
Panc ca spread
- Lymphatic
Panc ca locations
70% are in head
Unresectable panc ca
Invasion of PV, SMV, or retroperitoneum
Mets to peritoneum, omentum, or liver
Mets to celiac or SMA nodal system (nodes outside area of resection)
Panc ca histology
- Ductal adenocarcinoma (90%)
- Papillary or mucinous cyst adenocarcinoma (more favorable prognosis)
Signs of cancer (versus dilated duct from chronic panc) on MRCP
- Irregular narrowing
- DIsplacement
- Destruction
Double duct sign
Dilation of both PD and CBD in pancreatic head tumors on CT scan
Treatment of unresectable panc ca
Biliary stents or hepaticoJ for biliary obstruction
GastroJ for duodenal obstruction
Celiac plexus ablation for pain
Whipple complications
Delayed gastric emptying most common (tx with metoclopramide)
Fistula (conservative tx)
Leak (drains and tx like fistula)
Marginal ulceration (PPI)
Bleeding after Whipple or other pancreatic surgery
Angio for embolization (tissue planes very friable early after surgery, and bleeding hard to control operatively)
Postop chemoXRT for panc ca
Gemcitabine
Prognosis of panc ca (if non metastatic)
Related to nodal invasion and ability to get a clear margin
Pancreatic endocrine neoplasms
1/3 are nonfunctional
90% of nonfunctional are malignant
More indolent and protracted course
Metastatic disease precludes resection
Meds for nonfunctional PETs
5FU and streptozocin
Most common mets in nonfunctional and functional PETs
Liver
Endocrine pancreatic tumors: functional or nonfunctional?
2/3 are functional
Octreotide in PET?
Effective for insulinoma, glucagonoma, gastrinoma, VIPoma
PETs location?
Gastrinom and somatostatinoma in pancreatic head
Most common islet cell tumors?
Insulinoma; Gastrinoma in MEN-1 patients
Fasting hypoglycemia (<50), symptoms of hypoglycemia (palps, tachy, diaphoresis), and relief with glucose?
Whipple’s triad for insulinoma
Insulinomas
90% are benign and distributed throughout the pancreas
Dx of insulinoma
Insulin to glucose ratio > 0.4 after fasting
Increased C-peptide and proinsulin (if not elevated, suspect Munchausen’s syndrome)
Tx of insulinoma
Enucleate if < 2 cm; formal resection if > 2 cm
For metastatic disease: 5-FU and streptozocin; octreotide
ZES
Gastrinoma
50% malignant, 50% multiple
75% spontaneous, 25% MEN-1
Most in gastrinoma triangle (Pessaro’s): CBD, neck of pancreas, third portion of duodenum
Refractory or complicated ulcer disease and diarrhea (improved with PPI)
Gastrinoma
Dx of gastrinoma
Serum gastrin > 1000
(Is at least greater than 200 usually)
Secretin stimulation test: increases gastrin in ZES (in normal patients it decreases gastrin)
Tx of gastrinoma
Enucleation if < 2 cm, formal resection if > 2 cm
Malignant disease: excise suspicious nodes
What do you do if you cannot find the tumor in gastrinoma?
- IOUS
2. Perform duodenostomy and look inside duo for tumor (15% of microgastrinomas there)
Duodenal gastrinoma
Resect with primary closure; may need Whipple if extensive; be sure to check pancreas for primary
Debulking
Can improve symptoms in gastrinoma, all functional PETs
Single best study for localizing gastrinoma?
Octreotide scan
Diabetes, stomatitis, dermatitis, weight loss
Glucagonoma (necrolytic migratory erythema - can treat with zinc, aas, or fatty acids))
Dx of glucagonoma
Fasting glucagon > 500
Glucagonoma
Most are malignant
Most are in distal pancreas
Tx of glucagonoma
Debulking and octreotide
Hypokalemia, achlorhydria, diarrhea
VIPoma aka Werner-Morrison syndrome
WDHA
Dx of VIPoma
Exclude other causes of diarrhea; high VIP levels
VIPomas
Most are malignant and in distal panc (like glucagonoma); 10% are extrapancreatic (retroperitoneal, thorax)
Diabetes, gallstones, steatorrhea, hypochlorhydria
Somatostaninoma: very rare
Dx of somatostatinoma
Fasting somatostatin level > 10
Somatostatinomas
Most malignant; Most in HEAD of pancreas (also peri-ampullary, proximal panc, panc-duodenal groove)
Tx of somatostatinoma
Cholecystectomy with resection