RIU 330 - Pancreas (part 1)

head

1

1= head of pancreas 2= ivc

1 and 2

neck

2

body

3

tail

4

Uncinate Process

5

pancreatic duct

6

accessory pancreatic duct

7

not compatible with life

Agenesis of pancreas

- developmental malformation - Ventral pancreatic bud abnormally encircles the 2nd part of the duodenum: forms a ring of pancreatic tissue that may cause duodenal narrowing (obstruction)

Annular pancreas

- The anterior border is the posterior wall of the antrum of the stomach. - The neck of the pancreas forms the right lateral border. - The splenic vein courses across the postero-medial surface of the pancreas to join the main portal vein.

Body of the Pancreas: anterior border? right lateral border? where is the splenic vein

- Largest section of the pancreas - Anterior to: -- Aorta -- Celiac axis -- Left renal vein -- Left Adrenal gland -- Left Kidney - Tortuous splenic artery is the superior border of the gland.

Body of the Pancreas: how big it is? anterior to what structures? where is the splenic artery

- Echogenicity: pancreas > liver, </> spleen (depends on fatty/fibrous texture) - Echotexture: Homogeneous - Surface: Smooth to slightly lobular (islets of Langerhans)

Characteristics of the Normal Pancreas: echogenicity (compared to liver and spleen), echotexture, surface

- Head <3 cm; - Neck <2.5 cm - Body <2.5 cm - Tail <2.0 cm

Characteristics of the Normal Pancreas: size: head, neck, body, tail

•Fluid collections •Pseudocysts •Hemorrhagic pancreatitis •Phlegmonous pancreatitis •Pancreatic Abscess

Complications of Pancreatitis

•Pseudocysts are always acquired; they result from trauma to the gland or from acute or chronic pancreatitis. •Pseudocysts develop in 10% to 20% of patients with acute pancreatitis. •Pseudocysts develop 4 to 6 weeks after the onset of pancreatitis.

Complications of Pancreatitis: Pseudocysts: how do they form? what % of patients develop them with acute? how long after onset do they develop?

•Pancreatic and parapancreatic fluid collections develop. •Fluid collections may resolve spontaneously, but those that do not are recognized as pseudocysts.

Complications of Pancreatitis: fluid collections: what kinds develop? do they resolve?

- Agenesis - very rare, ranges in severity - Pancreas divisum - very common, happens in 10% of births - Ectopic pancreatic tissue - uncommon, 0.2% - Annular pancreas - uncommon, 0.4%

Congenital Anomalies of pancreas (4) + commonality of each

Secondary duct that drains the upper anterior head

Duct of Santorini

- Primary duct, extending the entire length of the gland - Receives tributaries from lobules at right angles and enters the medial second part of the duodenum with the common bile duct at the ampulla of Vater (guarded by the sphincter of Oddi)

Duct of Wirsung: where does it extend through? what does it joins with and where?

- referred to as heterotopic, accessory, or aberrant pancreas, - defined as pancreatic tissue lacking anatomic and vascular continuity with the main body of the gland

Ectopic pancreas: another name and def

- Most inferior portion of the gland - Anterior to the inferior vena cava, - To the right of the portal-splenic confluence - Inferior to the main portal vein and caudate lobe of the liver - Medial to the duodenum as it "lies in the lap" of the C-loop of the duodenum - The splenic vein forms the posterior medial border of the pancreas.

Head of the Pancreas: most inferior portion of what? anterior to what? to the right of? inferior to what? medial to what? posterior medial border?

The gland is enlarged and echogenic, secondary to freshly clotted blood.

Hemorrhagic Pancreatitis sonographic appearance

- Rapid progression of acute pancreatitis with the rupture of pancreatic vessels and subsequent hemorrhage - Diffuse enzymatic destruction of the pancreatic substance is caused by a sudden escape of active pancreatic enzymes into the glandular parenchyma. - Enzymes cause focal areas of fat necrosis in and around the pancreas, which leads to rupture of pancreatic vessels and hemorrhage. - Nearly half of these patients have sudden necrotizing destruction of the pancreas after an alcoholic binge or an excessively large meal.

Hemorrhagic Pancreatitis: how does it occur? enzymes cause what? when does this occur i many patients?

- Most common location of a pseudocyst: the lesser sac, anterior to the pancreas and posterior to the stomach. - Second most common location: anterior pararenal space - Fluid occurs more commonly in left pararenal space than in the right.

Locations of a Pseudocyst: most common, second most common, what side of pararenal space

- Aorta - Inferior vena cava. - Portal-splenic confluence - Superior mesenteric vein - Superior mesenteric artery - Splenic Vein

Major posterior vascular landmarks of the pancreas are

- Lesser sac - Anterior pararenal spaces - Mesocolon - Perirenal spaces - Peripancreatic soft-tissue spaces

Most common sites for fluid collection: extrapancreatic

- Anterior to the portal-splenic confluence or superior mesenteric vein - The portal vein is formed posterior to the neck by the junction of the superior mesenteric and splenic veins. - The neck is located between the pancreatic head and body and often is included as "part of the body" of the gland.

Neck of the Pancreas location: anterior to what? where is the portal vein? between what regions of pancreas?

pancreas eat itself

Outer digestion of pancreas

In utero, pancreas normally begins as two separate parts which fuse. In PD, ducts don't fuse and the pancreas is drained by 2 separate ducts

Pancreas divisum: what normally happen to pancreas in utero and what happens with PD

duct or Wirsung and duct of santorini

Pancreatic Ducts

- Insulin, ALPHA cell, Glucose to glycogen - Glucagon, BETA cell, Glycogen to glucose - Somatostatin, DELTA cell, Alpha and Beta inhibitor (poorly understood)

Pancreatic Endocrine Functions: hormone name, cell type, and action (3)

- Amylase (digestion of carbs) - Lipase (fat) - Glucose (endocrine function of pancreas) - Urine amylase

Pancreatic Laboratory Tests (4)

- Supine patient - Low frequency curvilinear transducer (3-5 MHz) - Oblique-transverse orientation to elongate organ - Scan window is midline 2-4 cm below xiphoid process - Increase pressure - patient should be NPO so stomach doesn't shadow or compress pancreas

Pancreatic Scan Technique: patient position, frequency and type of transducer? orientation of probe? scanning window? pressure amount? state of patient?

•Upper abdominal pain; epigastric (very painful) •Abdominal pain that radiating to the back •Post prandial abdominal pain •Nausea •Vomiting •Point tenderness •Elevate amylase & lipase (3x)

Pancreatitis: Clinical Presentation: acute symptoms

•Losing weight without trying (aren't able to digest food because no pancreatic enzymes) •Oily, smelly stools (steatorrhea) - Patient may still have pain, but it's not as severe as acute

Pancreatitis: Clinical Presentation: chronic symptoms

•Alcohol abuse •Gallstones •Metabolic disorders (high levels of lipids) •Trauma •Malignancy •Infection •Toxins (spider bites, scorpion stings) •Idiopathic (20%) (don't know cause)

Pancreatitis: Clinical Presentation: risk factors

- Occurs when the pancreas becomes damaged and malfunctions as a result of increased secretion and blockage of ducts. - When this occurs, the pancreatic tissue may be digested by its own enzymes; (the enzymes get out of the protective bubble and eat pancreatic tissue)

Pancreatitis: what does it occur as a result to? what can occur to the pancreatic tissue?

- inflammation of the pancreas. -May be classified as acute or chronic. -Is further classified as mild to severe.

Pancreatitis: what is it? classifications?

- A phlegmon is an inflammatory process that spreads along fascial pathways - Causes localized areas of diffuse inflammatory edema of soft tissue that - May proceed to necrosis and suppuration.

Phlegmonous Pancreatitis: phlegmon spreads long what? what does this cause? what can it proceed to?

localized walled-off pancreatic fluid collection by fibrotic tissue; may be defined as a collection of fluid that arises from the loculation of inflammatory processes, necrosis, trauma, or hemorrhage

Pseudocysts: what is it? arises from what happening

Can resolve on own if less than 6cm; larger than 6 cm and has symptoms may have to be drained through the stomach or duodenum

Pseudocysts: what size will it resolve on its own; if it's bigger where is it drained

- occurring in 5% of patients; In 3% of these patients, drainage is directly into the peritoneal cavity. - Clinical symptoms are sudden shock and peritonitis. - Mortality rate is 50%. - Pancreatic ascites occurs when the pancreatic pseudocyst ruptures into the abdomen. - May rupture and drain into peritoneal cavity and can cause peritonitis

Spontaneous Rupture of a pancreatic Pseudocyst: occurring in what % of patients? what happens in 3% of these patient? clinical symptoms? mortality rate? what occurs when it ruptures into abdomen and peritoneal cavity?

- Begins to the left of the lateral border of the aorta and extends toward the splenic hilum - Splenic vein is the posterior border of the body and tail. - Splenic artery forms the superior border of the tail. - Stomach is the anterior border of the tail.

Tail of the Pancreas: where does it begin and extend? posterior border? superior border? anterior borders?

test measuring pancreatic enzyme levels of urine amylase

Urine amylase

- Transverse - Horseshoe - Sigmoid - L-shaped - Inverted V

Variations in the lie of the pancreas include (diff shapes)

- Anterior and inferior pancreaticoduodenal arteries supply the head and part of the duodenum. - The splenic artery supplies the body and tail of the pancreas through 4 smaller branches -- 1. Suprapancreatic -- 2. Pancreatic -- 3. Prepancreatic -- 4. Prehilar and hepaticartery (gastroduodenal artery)

Vascular Supply of pancreas: what supplies the head and part fo duodenum with blood? what supplies the body and tail with blood (4)?

inflammation of the pancreas caused by the inflamed acini releasing pancreatic enzymes into the surrounding pancreatic tissue

acute pancreatitis

•Enlarged, edematous gland (swollen) •Hypoechoic •Heterogeneous •May be associated with: - thrombosis - Gallstones

acute pancreatitis sonographic appearance

- A = gastroduodenual artery - B = splenic vein - C = portal-splenic confluence - D = IVC - E = aorta - F = SMA

all

- Septations with low-level internal echoes. - Excessive internal echoes. - Calcification around the rim.

atypical pancreatic pseudocyst sonographic appearances

the recurring destruction (acute pancreatitis) of the pancreatic tissue that results in atrophy, fibrosis, scarring, and the development of calcification within the gland; impairment of exocrine and endocrine function

chronic pancreatitis

•Echogenic foci throughout •Enlarged pancreatic duct •Atrophic size (smaller) •May be associated with: - thrombosis -Gallstones -(replaced by fibrotic tissue)

chronic pancreatitis sonography appearance

1.Head 2.Uncinate Process 3.Neck 4.Body 5.Tail

division of pancreas

a set of glands that secrete hormones into the bloodstream

endocrine: where to secretions go

chemically active molecules that break down complex biomolecules that we consumer in food into smaller molecules that we can absorb; lipids, carbs, proteins, nucleic acids - so that biomolecule components can fit through cellular membrane

enzymes function + why

gland that secretes its products through excretory ducts to the surface of an organ or tissue or into a vessel - NOT released into blood vessels directly

exocrine: where to secretions go

glycogen to glucose, results in increase of glucose in blood when we are hungry to feed our brain

glucagon result to blood sugar levels

- small, curved tip at the end of the head of the pancreas. - Lies anterior to the inferior vena cava and posterior to the superior mesenteric vein and artery.

head of pancreas: uncinate process: what is it? and what does it lie anterior to and posterior to?

- chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues - even tho they are in our blood, they are only functional for their target tissue

hormones

head is broken down into head proper and uncinate process

how can the head of the pancreas be broken down

SMV and SMA are posterior to pancreas near head/neck and changes to anterior at the uncinate process

how to the SMA and SMV course through pancreas region

glucose to glycogen, results in decrease of glucose in the blood

insulin result to blood sugar levels

no, not diagnostic because it is very subjective but it is used quite often because it's quick, easy, gather baseline for patient, and can eliminate the presence of gallstone

is US considered to be diagnostic for the pancreas

- Anterior to the first and second lumbar bodies - Located deep in the retroperitoneum, except for a small portion of the head (which is intraperitoneal) - Behind the lesser omental sac. - Extends in a horizontal oblique lie from the second portion of the duodenum to the splenic hilum.

location of pancreas in abd cavity: vertebral bodies? is it within the peritoneum? behind what? what does it extend to and from horizontally

Spontaneous rupture

most common complication of a pancreatic pseudocyst

head

most inferior portion of pancreas

- Lipase = Fats - Amylase = Carbohydrates - Trypsin, chymotrypsinogen, carboxypeptidase = Proteins - Nucleases = Nucleic acids - components of pancreatic juice, goes into pancreatic duct to duodenum

pancreas exocrine function: enzymes secreted and their targets? where do these enzymes go?

- regulates blood sugar (insulin & glucagon) - Secretes pancreatic juice which breaks down all categories of food - produces digestive enzymes for fats, carbs, proteins, nucleic acids

pancreas function

- digestive system/exocrine - endocrine system

pancreas is involved in what body systems

- All are stored and secreted from the pancreas as inactive proforms surrounding by protective bubble that are activated in the duodenum by trypsin - activation allows them to functional; they are very aggressive and destroy anything they come in contact with (means they can kill our tissue with disease)

pancreatic enzymes: how do they travel within pancreas and what is needed for them to be functional

Alkaline mixture of water, enzymes, zymogens, sodium bicarbonate and other electrolytes

pancreatic juice

neutralize stomach acid as it enters the small intestine

pancreatic juice: what is the function of bicarbonate

- pancreatic juice become thick, can't drain, builds up pressure in the ducts, enzymes release and eat tissue - 75% of chronic pancreatitis

pancreatitis: Alcohol abuse: how it occurs and type of inflammation

Acute diffuse inflammation of subcutaneous connective tissue describes that can progress to necrosis and suppuration

phlegmon

Area just posterior to the neck of the pancreas, where the splenic vein meets the superior mesenteric vein. Together, these veins form the portal vein.

portal-splenic confluence

Stomach, duodenum and colon

superior and lateral borders of pancreas

superior border

the celiac axis serves as the _____ of the pancreas

posterior border

the portal venous system is the _____ of pancreas

direct puncture to the pancreas or during medical procedure

trauma of pancreas to cause pancreatitis

Atypical pancreatic pseudocyst; Excessive internal echoes.

typical or atypical

Atypical pancreatic pseudocyst; Septations with low-level internal echoes.

typical or atypical

Typical pancreatic pseudocyst

typical or atypical

Typical pancreatic pseudocyst. A, Aorta; F, Fluid; L, liver; P, pancreas;PS, pseudocyst.

typical or atypical

anechoic, rounded, well defined

typical pancreatic pseudocyst sonographic appearances

Venous drainage is through tributaries of the splenic and superior mesenteric veins.

vascular suppler: venous drain occurs through what?

- Acute pancreatitis = severe epigastric pain; chronic doesn't show this - laboratory values of serum amylase and lipase are usually normal in chronic pancreatitis, but almost always elevated in patients with acute disease - Patients with chronic pancreatitis may be asymptomatic over long periods of time, may present with a fibrotic mass, or may have symptoms of pancreatic insufficiency without pain

ways to distinguish chronic vs acute pancreatitis: type of pain? laboratory values? chronic clinical pres

-Between amylase and lipase, lipase is more specific for acute -Amylase rises first -Lipase rises after, but lasts longer, why it's more specific

what pancreatic enzymes is more specific to acute pancreatitis

majority of the pancreas lies within the retroperitoneal cavity, with the exception of a small portion of the head that is surrounded by peritoneum

what portion of pancreas is covered in peritoneum

spincter of oddi; blocks pancreatic ducts, increases pressure in pancreas, enzymes get out, and damage tissue of pancreas - 90% of acute pancreatitis

where are gallstones location to cause pancreatitis + what kind of pancreatitis does it cause