pancreas - Caangay.com

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I. Pancreas
A. Anatomy
- retroperitoneal
- extends transversely behind the stomach
- weight – approximately 85 grams
- length – 12-15 cm.
1. Anatomic relationships
a. head of the pancreas – lies
over the aorta and under the
stomach and transverse colon,
posteromedial to the IVC
i. superior limit – portal vein
ii. anterior limit – gastro-duodenal
artery
iii. CBD courses posteriorly to the
head and partially within
iv. Common blood supply with the
duodenum
b. uncinate process – lies posterior
to the SMV and anterior to the IVC
c. tail – closely related to the
spleen
d. neck – lies at the confluence of
splenic and mesenteric veins
B. Blood supply
1. Anterior and posterior arcades –
supply the head of the pancreas; superior
component comes from the gastroduodenal
artery and the inferior component comes
from the superior
mesenteric artery
2. Inferior pancreatic artery –runs inferior to
the organ, in intimate contact
with the
pancreas
3. Superior pancreatic artery – present
50%-90% of patients
a. arises from the splenic artery,
hepatic artery, superior
mesenteric or iliac artery
b. postero-superior portion of the
neck and body of the pancreas
4. Splenic and left gastroepiploic artery
– supplies body and tail of the pancreas
in
5. Venous drainage
a. follows the course of the
arteries
b. confluence of right
gastroepiploic vein, anterosuperior
pancreaticoduodenal vein, middle
colic vein
c. forms the gastrocolic trunk which
empties directly to the SMV at the
inferior border of the neck of the
pancreas
6. Ductal system – drains into the
duodenum
a. Duct of Wirsung – empties into
the ampulla of Vater together
with the CBD
b. Duct of Santorini – drains into the
minor papilla approximately 2 cm
above and medial to the ampulla of
Vater (minor ductal system)
II. Pancreatitis
A. Acute pancreatitis
1. Gallstone pancreatitis
a. needs a common channel
between the CBD and the
pancreatic duct
b. high proportion of causes with
gallstone pancreatitis have recoverable
biliary calculi in the stools
c. spasm of the sphincter of Odi as a
stone passes causes reflux of bile into
the pancreatic duct which results in the
destruction of the pancreatic
parenchyma
2. Alcohol pancreatitis
a. alcohol causes increase in
protein concentration in the
pancreatic juice  calcifications in
duct
b. ductal obstruction causes
inflammation  destruction of
parenchyma
the
3. Post-operative pancreatitis
a. occurs ususally after gastric,
biliary tract surgery, or
splenectomy
b. ligation or laceration of the
duct may be the cause of the
pancreatitis
c. mortality – approximately 50%
B. Clinical manifestations of acute pancreatitis
1. mild abdominal discomfort to profound
shock
2. epigastric pain radiating to the back
nausea and vomiting
with
3. discomfort may be relieved by sitting and
aggravated by lying down
4. may have mild to moderate abdominal
tenderness
5. may present with a surgical abdomen
6. severe pancreatitis may lead to
retroperitoneal hemorrhage which
leads to
a. 3rd space fluid loss
b. hypovolemia
c. hypotension
d. tachycardia
e. blood dissection– Grey Turner’s sign
(flank ecchymosis)
- Cullen’s sign (periumbilical
ecchymosis
7. pain usually follows 1-4 hours after a
heavy meal and intake of alcohol
C. Diagnosis
1. History and Physical Exam
a. serum amylase – increased in
95% of cases; 5% false negative
i. 75% of patients with
abdominal pain and increased
amylase have pancreatitis
ii. other causes of increased
amylase
- acute cholecystitis
- CBD stone with or without
cholangitis
- Perforated peptic ulcer
- Strangulated small bowel
- acute alcoholism
- Cancer of the pancreas
- Mumps
iii. amylase level over 1,000
Somogyi-Nelson units often
indicates biliary tract disease
with panceatitis
iv. 200-500 units indicates
alcoholic pancreatitis
b. amylase – creatinine ratio
- diagnostic when amylase
output in the urine exceeds
300 u in one hour and ratio of
amylase:creatinine clearance of >5
c. serum calcium - <7.5 mg/dl generally
indicates poor prognosis
d. radiology (x-ray) – relatively insensitive
e. barium studies –
i. widened duodenal C-loop
ii. Pad sign – obliteration of the
duodenal mucosal folds
f. ultrasound – swelling of the
pancreas and loss of tissue planes
g. CT scan – findings similar to
ultrasound but with a higher
resolution
D. Treatment
1. Resuscitation – replacement of fluid
losses and electrolytes
2. Blood transfusion in hemorrhagic
pancreatitis
3. Calcium gluconate through IV
4. NGT suction – decrease GIT
and pancreatic stimulation
distension
5. Antibiotics – reduce risk of abscess formation
6. Meperidine
7. Surgery
a. confirm diagnosis in cases
which do not respond medically
b. relieve ductal obstruction
c. drain the lesser sac
E. Prognosis – Ranson’s Criteria
1. Admission
a. > 55 years old
b. WBC count > 16000
c. FBS > 200 mg/dl
d. LDH > 350 units/ml
e. SGOT > 250
2. 48 hours after admission
a. drop in hematocrit by > 10%
b. increase in BUN of 5 mg/dl
c. calcium level < 8 mg/dl
d. PaO2 below 60 mmHg
e. base deficit > 4 meq/L
f. third space fluid loss > 6 L
*Prognosis
Number of criteria present
0-2
Mortality rate
0.9%
3-6
33%
7-8
100%
III. Chronic Pancreatitis
- clinical entity rather than a pathologic process
- organ becomes small, indurated and nodular
and edges become rounded
- alternating areas of strictures and dilatations
in the duct with calcifications
-primary etiology: chronic alcoholic
pancreatitis with progressive fibrosis without
ductal dilatation or calcification
A. Clinical manifestation
1. late 30’s or 40’s
2. history of alcoholism and
recurrent attacks of pancreatitis
3. pain
4. may diabetes or steatorrhea
5. frequent finding of pseudocyst
6. anorexia and weight loss
B. Diagnosis
1. upper GI series
2. ERCP
3. ultrasound/CT scan
4. calcifications on x-rays
C. Treatment
1. analgesics
2. endocrine and exocrine
replacement
3. stop alcohol intake
4. surgery (Peustow procedure)
IV. Psedocyst of the Pancreas
A. Causes
1. pancreatitis – 75%
- alcoholic pancreatitis
- 4th and 5th decade of life
2. trauma – 25%
B. Pathology
1. fibrous wall surrounding a
collection of pancreatic juice and
necrotic or suppurative pancreatic juice
2. unilocular and located in the
lesser sac
3. fluid varies from clear and
colorless to brown or green
C. Clinical manifestations
1. pain, fever, and ileus appearing
2-3 weeks after an initial attack of
pancreatitis
2. pain radiating to the back
3. jaundice
d. non-tender palpable mass –
(75% of patients)
4. change in size of the mass due to
partial drainage
D. Diagnosis
1. continued elevation of serum
amylase
2. CT scan – diagnostic tool of
choice
3. ultrasound
4. upper GI series
5. ERCP
E. Treatment
1. surgery
a. to prevent complications
such as infection,
hemorrhage, rupture
b. pseudocysts rarely resolve
once thick fibrous wall has
developed
c. pseudocyst should be treated
only after 5-6 weeks from
discovery
2. types of surgery
a. external drainage
b. internal drainage - best
i. cystenterostomy
ii. cystgastrostomy
c. cyst wall should be excised for
histopathology to rule out
malignancy
V. Pancreatic Tumors
A. Etiology
1. cigarette smoking
2. coffee
3. biliary lithiasis
B. Pathology
1. Cystadenoma/Cystadenocarcinoma
a. rare; predilection for females
b. cystic spaces divided by firbous
septa; vascular
c. better prognosis than
adenocarcinoma
d. Tx. - resection
2. Adenocarcinoma
a. 90% of cases; usually at the
head
b. periampullary malignancy
i. head of the pancreas –
83%
ii. Ampulla of Vater – 10%
iii. Duodenum – 4%
iv. Common bile duct – 3%
c. Clinical manifestations
i. weight loss – most common
ii. pain – dull epigastric pain that
radiates to the back; aggravated
by eating
iii. progressive jaundice – 75%;
head of the pancreas
iv. anorexia and weakness – 50%
v. pruritus
vi. hepatomegally
vii. enlarged palpable gallbladder –
Courvesiure’s gallbladder
d. Laboratory work-up
i. alkaline PO4, transaminases,
Bilirubin
ii. UGIS
iii. CT scan – CT scan guided
biopsy
iv. ERCP/PTC
e. Treatment
i. Prior to surgery – improve overall
condition of the patient
ii. Whipple’s surgery – for resectable
lesions – renal failure most common
complication
iii. Cholecystojejunostomy/ Gastrojejunostomy – bypass for unresectable
lesions
iv. injection of 95% alcohol to the celiac
plexus – relief of pain
v. poor risk patients
- PTC/PTBD
- 5-FU/external beam
radiation
3. Zollinger-Ellison Sybdrome –
Ulcerinogenic Tumors of the Islets
a. male>female; 3rd to 4th decade
b. slow growing tumor of the Islets of
Langerhan
c. associated with Multiple Endocrine
Neoplasia – adenoma of the pituitary,
parathyroid, pancreatic islets (beta
cells), and adrenal cortex
d. secretes GASTRIN
e. Triad
i. fulminant and complicated
peptic ulcers often in atypical
locations
ii. Extreme gastric hypersecretion
iii. Non- beta cell tumor of the
Islets
f. signs and symptoms
i. acid peptic disease
ii. Distressing watery diarrhea
iii. steatorrhea
g. diagnosis
i. UGIS
ii. Gastroscopy
iii. Serum gastrin determination
iv. CT scan
h. treatment
i. total gastrectomy
ii. Resection of the tumor
iii. Proton pump inhibitor
iv. Streprozotocin - metastasis
4. Hyperinsulinism – Islet cell tumor
- b-cells – hypersecretion of insulin causing
hypoglycemia
a. pathology
i. benign adenoma – 75%
ii. Suspected malignant – 13%
iii. Clearly malignant – 12%
iv. Diffuse adenomatosis
v. size of the tumor has no relation
to severity
b. clinical manifestation
i. 4th-7th decade
ii. Associated with MEA-I
hyperinsulinism
iii. Two general forms
- rapid fall of blood sugar
- gradual fall in blood
sugar
iv. Whipple Triad
- hypoglycemic attack during
fasting or exertion
- FBS > 50 mg/dl
- symptoms relieved by intake of
glucose
c. diagnosis
i. blood sugar and insulin levels
ii. Pancreatic angiography and
venous sampling
iii. CT scan
d. treament
i. pre-operative management
- adequate provision of glucose
- ACTH and Cortisol
- Diazoxide – inhibits release of
insulin
ii. Surgery
- benign – excision
- malignant – pancreatic resection
- improvement seen 30 minutes
after excision of the lesion
- Streptozoticin - metastasis
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