1
Q
A
2
Q
General principles of the GI tract
A
- The major portion of the GI tract is contained within the abdominopelvic cavity (part of esophagus in thoracic cavity)
- principle functions of the GI tract are digestion and nutrient absorption
- The motor innervation of the GI tract is via the autonomic nervous system. (can’t control)
3
Q
ESOPHAGUS
A
- approximately 25-30 cm long (10 inches)
- extends from the lower part of the laryngopharynx and passes through the esophageal hiatus of the diaphragm. It makes an abrupt turn to the left from the esophageal hiatus and enters the cardiac opening of the stomach (LES (Lower esophageal sphincter) or cardiac sphincter)
- The cardiac sphincter is well developed circular muscle fibers, that prevent the regurgitation of food from the stomach. It is not a true sphinter.
4
Q
ESOPHAGEAL FUNCTION
A
- tube that connects the larynx with the stomach
- acts as a passage between the two structures, so that the food can reach the stomach.
5
Q
VASCULATURE of the Esophagus
A
- Arteries:
- upper third= inferior thyroid artery
- middle third= branches from the descending thoracic aorta.
- lower third= left gastric artery
- Veins:
- upper third portion= inferior thyroid veins
- middle third= azygous vein
- lower third= left gastric vein
6
Q
LYMPHATIC DRAINAGE of the esophagus
A
- upper third drain into the deep cervical nodes
- middle third drain into the superior and posterior Mediastinal nodes
- lower third drain into the celiac nodes
7
Q
Esophageal Varices
A
- In the event of portal hypertension, the development of esophageal varices can occur
- These veins dilate due to high pressure directly beneath the mucosa, and into the lumen.
- They are subjected to mechanical trauma during swallowing, vomiting, or the passage of diagnostic instrumentation.
8
Q
Treatment for Varices?
A
- Varices banding
- EGD, grab varices and snap a rubberband around them
- helps with bleeding
9
Q
Hiatal Hernia
A
- Herniation of the stomach through the esophageal hiatus produces a sac-like dilation above the diaphragm
- Gastric reflux may cause tissue changes in the distal esophagus
- Stomach tissue may begin to grow into the esophagus– Barrett’s esophagus – 10% chance of turning into cancer.
10
Q
GERD & diagnosis & Treatment
A
- Gastric esophageal reflux disease (heartburn)
- Esophagitis – Gastric contents reflux into the esophagus, burning and inflaming the unprotected esophageal mucosa.
- diagnosis is made by: Manometry; Esophagoscopy; 24 hour pH measurements; cineradiography
- Tx: Antacids; Histamine2-receptor antagonists to reduce acidity; wt. reduction; Stop Smoking and drinking alcohol; elevation of the head at night.
- Surgical: Nissen fundoplicaion
11
Q
Laparoscopic Nissen Fundoplication
A
- Surgical treatment for GERD
- wrap crus of stomach around esophagus
- stronger cardiac sphincter
12
Q
Achalasia (symptoms, diagnosis, treatment)
A
- It consists of abnormal peristalsis in the body of the esophagus (stenosis (narrowing) of the esophagus)
- Symptoms: dysphagia, regurgitation, wt. loss and frequently respiratory symptoms due to aspiration
- Dx: X-ray studies; Esophageal manometry; Esophagoscopy
- Tx: palliative (releiving pain without fixing problem) dilation of stricture (with bougies); esophagomyotomy with care not to damage the vagus nerve
13
Q
Tumors of the esophagus
A
- Benign tumors
- major problem is dysphagia, occasionally regurgitation and wt. loss
- Tx. is enucleation of tumor without violating mucosa. (ie. Snare)
- Malignant tumors
- Exact cause is unknown
- Dx: History of dysphagia and wt. loss; Contrast study; esophagoscopy; bronchoscopy; CT scan
- Tx: Surgical. Total thoracic esophagectomy with replacement with colon.
14
Q
STOMACH
A
- located in the left hypochondriac and epigastric regions of the abdomen
- Because it is suspended by mesenteries, it is a mobile and easily displaced organ with no fixed position
- Empty, the stomach is almost tubular or J-shaped; except for the bulge of the fundus, it may be almost entirely under the rib cage for protection
- holds 2L of food
15
Q
External Structure stomach
A
- composed of two sides, two curvatures, and two orifices
- The greater curvature, The lesser curvature
- The cardiac sphincter (LES) is connecting the esophagus to the stomach and pyloric sphincter connects the stomach to the duodenum
16
Q
Internal Structure of the stomach
A
- The mucous membrane lining the stomach is thick and vascular. It is thrown into numerous folds, known as rugae, which are predominantly longitudinal in direction. On distention of the stomach, these folds flatten out. It contains the glands and the gastric pits.
17
Q
Fibers of the stomach
A
- Longitudinal fibers
- Circular fibers
- Oblique fibers
18
Q
Divisions of the stomach (regions, parts)
A
- The cardia
- The fundus
- The corpus or body
- The pylorus
19
Q
FUNCTION of the stomach
A
- Trituration (mixing)
- formation of chyme
- acid enzymatic digestion and some absorption
- serving as a reservoir
20
Q
VASCULATURE of the stomach
A
- Arterial supply-the celiac artery through its three branches:
- left gastric artery
- splenic artery
- common hepatic artery
21
Q
Venous return and Lymphatic system of the stomach
A
- Veins generally parallel the arterial supply, but diverge significantly to join the hepatic portal system
- Lymphatic routes generally follow the arteries and are so named
22
Q
COMMON PROBLEMS of the stomach
A
- Gastritis – excessive vagal activity may stimulate the acid secreting gland too much. Aspirin and steroids may also produce gastritis
- Peptic ulceration– occur in the non-acid secreting region of the upper GI tract. May cause severe bleeding, obstruction from edema or scarring and peritonitis from rupture. May be treated with drugs that block acid secretion or selective vagotomy (reduces peptic secretions) H. pylori can also cause pepric ulcers
- Gastric Ulcers– Classified by location (stomach). More common in men
- Etiology: thought to be reflux of bile into stomach changing mucosal barrier and allowing gastric juices to damage mucosa; Drugs.
- Malignant Metastases – the venous and lymphatic drainage of the stomach is such that malignant cancer at this site can spread to other organs and regions.
23
Q
Greater Omentum
A
- Apron like structure that is a double fold of double layer peritoneum
- It attaches to the greater curvature of the stomach and to the anterior surface of the transverse colon to cover the intestines
- Contains adipose tissue and provides infection control and helps prevent spread of peritoneal infection
24
Q
Mesentery
A
- Double layered fold of peritoneum that contains the blood vessels, nerves, and lymphatic vessels that supply the intestinal wall.
25
SMALL INTESTINE
* divided into three parts but the differences are slight
* Duodenum
* Jejunum
* Ileum
26
Layers of the small intestine:
* Mucosa
* Submucosa
* Muscularis
* Serosa
27
DUODENUM
* shortest portion of the small intestine
* **10 inches in length from the pyloric sphincter to the duodenojejunal flexure**
* Loops in a C shape to the right
* **The suspensory ligament (of Treitz) is a surgical landmark** -- it basically denotes where it changes from duodenum to jejunum.
28
FUNCTIONS of duodenum
* **Primarily digestion**
* ****The chyme is mixed with the products of the liver and pancreas and absorbs toward the distal portion
29
VASCULATURE of the duodenum
* Arterial supply -- two sources
* celiac artery supplies the proximal and the
* superior mesenteric artery supplies the distal duodenum
* Venous supply --
* hepatic portal vein by way of the
* common hepatic vein and the
* superior mesenteric vein.
30
CLINICAL CONSIDERATIONS (duodenum)
* Since the venous and lymphatic route anastomose with those of the dorsal body wall, **carcinoma of the duodenum and pancreas frequently has poor prognosis**
* Most tumors are benign and most are polyps
* **Duodenal ulcers (peptic) are four times more frequent than gastric ulcers** and may require a Bilroth I gastroduodenal resection (small bowel resection) Complications include perforation, hemorrhage and obstruction. Dx and Tx similar to gastric ulcers.
31
JEJUNUM AND ILEUM
* The small bowel is **supported by the mesentery** proper. The jejunal loops tend to be in the left lateral region and the ileum tends to be in the pelvis. They are highly mobile (for peristalsis)
32
EXTERNAL STRUCTURES of Jejunum and Ileum
* Averages about **22 feet** ( 15-34 feet). There is no distinct boundary
* **Function is absorption**. Villi increase the surface area.
33
VASCULATURE of Jejunum and Ileum
* Arterial supply
* superior mesenteric artery
* Venous return
* hepatic portal system via the superior mesenteric vein
* Lymphatic drainage
* absorb and transport triglycerides and well as lymph to the circulation via the thoracic duct
34
FUNCTION of Jejunum and Ileum
* **Propel chyme through the gut**. Segmentation occurs at the rate of about 10 contractions a minute and corresponds to the frequency of borborygmi (stomach rumble). Peristalsis is not very forceful in the jejunum but becomes very pronounced in the ileum
* **Absorption of carbohydrates, triglycerides, and fatty acids, amino acids, vitamins, electrolytes, and water**
35
How much of the small intestine can you excise and live a normal life?
* up to 1/3
* survival is possible with as little as 18 inches
36
Meckels diverticulum
* A true **congenital** diverticulum, is a slight bulge in the small intestine present at birth and a vestigial remnant of the vitelline duct
37
Intestinal Obstruction
| (Mechanical or Paralytic obstruction)
* **Mechanical**: hernia, adhesions; tumor; intussusception; volvulus
* **Paralytic**: most commonly seen after **surgery**
* **don't paristalse, bowel paralyzed, take drugs for it**
* Effects of both: abdominal distention; loss of fluids and electrolytes; strangulation; gangrene perforation
* Cardinal symptoms: pain, absolute constipation, abdominal distention, and vomiting.
38
Inflammatory Bowel Disease
* Crohn’s Disease
* Ulcerative Colitis
* Etiology: **Unknown – same for both**
* Infectious agents
* Immunologic mechanism
* Genetic
* Psychological factors
39
Crohn's disease
* A chronic recurrent granulomatous disease involving small and large intestine (either or both)
* Involves the entire thickness of the bowel
* Intestinal wall is thickened, edematous and fibrotic. Mesentery is thickened and infiltrated with fat. Lymph nodes enlarged
* The mucosal layer is **“cobblestoned”**.
* **segmented can jump around**
40
Crohn’s Disease Signs and Symptoms
* Perirectal abscess
* Occasional attacks of diarrhea
* Progressive malaise
* Low grade fever
* Weight loss (10-20 lbs)
* Abdominal pain
* Intestinal obstruction
* Massive bleeding
* Acute perforation pain mimicking appendicitis
* Fever
* arthritis
41
Crohn’s Disease Diagnosis
* Tenderness in right lower quadrant
* Palpable abdominal mass
* Anal fistula
* Stools may have occult blood
* Sigmoidoscopy is usually normal
42
STRUCTURE colon
* Approx. 5 feet long. Fat filled tags are scattered over the surface. Longitudinal bands, teniae coli are about 1 cm wide and most obvious on the cecum and ascending colon. Muscle tone in the teniae coli results in sacculations (haustra) along the intestine.
43
Ulcerative Colitis
* A diffuse inflammatory disease of unknown etiology involving the mucosa and submucosa of the **large intestine**
* **Begins in rectum** and proceeds proximal to involve entire colon. **(no skip lesions like Crohn’s**), continuous
* May lead to strictures.
44
Ulcerative Colitis Signs and Symptoms
* Bloody diarrhea
* Abdominal pain
* Fever
* Anorexia
* Weight loss
* 30-40 BM’s/day
* Weakness
* May lead to megacolon
* Cramping
* Fatigue
* Nocturnal diarrhea
45
Ulcerative Colitis Diagnosis
* Rule out other causes of bloody diarrhea
* Sigmoidoscopy
* Barium enema
* Endoscopic mucosal biopsy
* Colonoscopy
46
Complications of ulcerative Colitis
* toxic megacolon
* dilatation of colon
* systemic toxicity
* contributing factors to megacolon
* use of laxatives
* narcotics
* anticholingeric drugs
* hypokalemia
* colon cancer
47
Tx of Ulcerative Colitis
* depends on extent of disease and severity of symptoms
* control acute manifestations
* prevent recurrence
* avoid certain foods
* caffeine
* lactose
* spicy foods
* gas-forming foods
* fiber supplements (decrease diarrhea and rectal symptoms)
* medication
* surgical removal of rectum and entire colon
* ileostomy
* ileoanal anastomosis
48
similarities between Crohn's Disease and Ulcerative Colitis
* inflammation of the bowel
* lack of known cause
* autoimmune reaction?
* infectious origin? ie. Chlamydia, atypical bacteria, mycobacteria
* pattern of familial occurrence; heredity component
* accompanied by systemic manifestations
* periods of remission and exacerbation
* diarrhea
* fecal urgency
* weight loss
* intestinal obstruction
49
What are 3 types of ostomies?
* ascending colostomy
* transverse colostomy
* descending colostomy
* bonus
* ileostomy
50
ASCENDING COLON
* **Three parts: cecum, appendix and ascending colon proper**.
* Its role is formation, transport, and evacuation of the feces. Its principle function is to convert liquid chyme into semisolid feces.
51
CECUM
* first part of the ascending colon. **The ileocecal junction is the location which the ileum terminates by entering the colon**
* ARTERIAL SUPPLY -- iliocolic artery, the terminal branch of the superior mesenteric artery.
52
VERMIFORM (worm-like) APPENDIX
* A narrow, hollow, muscular structure that arises from the posteriomedial aspect of the cecum about 2-3 cm below the ileocecal orifice. Suspended by the mesoappendix from the dorsal body wall which contains the appendicular artery, a terminal branch of the iliocolic artery
* no function
53
ASCENDING COLON PROPER
* **Located along the right side of the abdominal cavity**. The right colic flexure (hepatic flexure) marks the **transition between the ascending colon and the transverse colon.**
* VASCULATURE
* Arterial supply is from the middle colic, right colic and ileocolic branches of the superior mesenteric artery
* Venous return is via the superior mesenteric vein to the hepatic portal vein.
54
TRANSVERSE COLON
* The second and longest segment begins at the hepatic flexure and traverses to the splenic flexure. Approx. 18-20 inches and **suspended by mesentery**
* VASCULATURE
* Arterial supply-middle colic artery
* Venous return-via superior mesenteric vein and hepatic portal vein.
55
DESCENDING COLON
* The initial segment is located along the left side of the abdominal cavity. **Approx 10 inches**. It is usually smaller in diameter due to the decreased size of the feces
* VASCULATURE
* Arterial supply -- left colic branch of the inferior mesenteric artery
* Venous return -- inferior mesenteric vein to the splenic vein or superior mesenteric vein.
56
SIGMOID COLON
* The colon becomes peritoneal again. Approx. 10-15 inches. mucosa is primarily mucous cells. The primary function of the sigmoid colon is **storage of feces**
* VASCULATURE
* Arterial supply -- sigmoid arteries AND the rectosigmoid artery that arise from the **inferior mesenteric artery**
* Venous return-- inferior mesenteric vein to the splenic vein or **superior mesenteric vein**
57
Lymphatics of the colon
* Lymphatic system is of considerable importance **due to high frequency of colon cancer**. The major drainage from the descending and sigmoid via the left colic nodes which drain into the inferior mesenteric nodes, the para-aortic nodes and the thoracic duct. **Cancer may spread to the liver** and to the lymph nodes of the abdomen and pelvis
58
RECTUM
* Approx. 5 inches long. The **ampulla** lies just above the pelvic floor and is the widest part of the rectum
* VASCULATURE
* Arterial supply -- superior rectal (hemorrhoidal) artery , middle rectal (hemorrhoidal artery) and the inferior rectal (hemorrhoidal) artery
* Venous return -- same but veins
* Lymphatics -- parallel the arteries making metastasis wide within the abdomen and pelvis
59
CLINICAL CONSIDERATIONS OF RECTUM
* Prolapse of the rectum (turns inside out)
* Hemorrhoids-- compression of the inferior mesenteric artery (protrussion of vessels)
* Polyps- removed by snare
60
Rectal Retractors
1. Hill ferguson- 3 sizes, used more often
2. Hershman- 2 sizes
61
Evaluation of the colon, rectum and anus should include:
* **History** of recent and past bowel habits; rectal bleeding?; consistency of the stools; family history; pain?
* **Physical exam: anorectal exam--- inspection of the perianal region,; digital (finger) rectal exam; anoscopy;** rigid sigmoidoscopy; flex. sigmoidoscopy; exam stools for occult blood
* May use x-ray studies-- **plain film; contrast enema**
62
* Glassman curved
* **non-crushing**
* can have 45 degree angle, straight
* clamp bowel so no poop
63
* Doyen
* str or cvd
* not used frequently
64
Types of Anastomoses
65
Hints for GI surgery
* Positioning:
* Right Colectomy = supine
* Left Colectomy = low lithotomy (allens or yellowfin stirrups)
* May use betadine solution on cut edges of bowel
* Sutures:
* 3-0 Chromic SH for mucosa
* 3-0 Silk SH for serosa
* Always have staplers available
66
GIA linear staplers colors
* Red= vascular
* Blue= Thin/regular tissue
* Green= thick tissue
67
3 ways to check the anastomosis for leakage:
1. Clamp colon proximal to anastomosis, fill abdomen with saline and inject air through the rectum with an asepto, check for bubbles
2. Clamp colon proximal to anastomosis, inject saline through rectum with asepto, look for fluid
3. Rigid sigmoidoscope
68
set up for colon resection
* 6 curved hemostats
* 2 kelly hemostats
* 2 Tonsil hemostats
* 2 right angle clamps
* 2 babcocks
* 3 short allis’
* 2 long allis’
* 3 straight oshners
* 2 peons
* 2 sponge sticks
* 2 curved non-crushing GI clamps (doyens)
* 2 angled non-crushing GI clamps (glassmans)
* 2 straight non-crushing GI clamps (glassmans)
* 2 Allen clamps
* #3 KH with #10 KB
* #3 long KH with #15 KB
* Curved and straight mayo scissors
* Regular and long metz scissors
* Long russian TF
* 2 pair DeBakey TF
* Self-retaining retractor (bookwalter)
* Goulet
* Deavers
* Notes:
* Upon closure you need to don clean gloves and use clean instruments for closing
* Mayo setup will be necessary for the “down” person (KY jelly, EEA device, scissors)
69
* Nathanson Liver Retractor
70
Setup for Nissen Funduplication
* Trocars: 5 10 mm and 2 5 mm
* 2 laparoscopic graspers
* 2 laparoscopic dissectors
* Laparoscopic scissors
* Nathanson Liver Retractor
* #3 KH with #15 KB
* Straight mayo scissors
* Adson TF with teeth
* TF with teeth
* Camera / scope/ light cord / 30° angle scope
* Antifog
* Knot pusher
71
Bariatric Surgery
* Weight-Loss Surgery
* Changing the anatomy and physiology of the digestive system reducing the amount of food it can accommodate and/or the amount of calories and nutrients it can absorb
* * Note: Hospitals accommodations Special equipment
* hubbermat, can bed carry enough weight, trocars long enough, footboard on bottom of bed
72
Who is eligible for bariatric surgery?
* The patient is least 100 pounds above ideal weight
* The patient has a Body Mass Index (BMI) of 40 or higher
* The patient has a BMI of 35 or higher and also suffers from serious obesity-related health problems (co-morbidities), such as Diabetes Mellitus, Elevated Lipids, Hypertension, Depression, Heart Disease, Degenerative Joint Disease, and Sleep Apnea
* The patient is between 15 and 60 years of age
* The patient has a history of obesity
* The patient has tried non-surgical weight-loss treatments without success, and has documented such attempts
* The patient has no history of substance abuse, or has current success in a recovery program
* The patient has no major psychiatric disorders
73
Types of Bariatric Surgery
* Restrictive
* Lap-Band
* Gastric Sleeve
* Roux-en-Y
* Malabsorptive
* Roux-en-Y
74
Lap Band
* Restricts how much the stomach can hold by putting an adjustable band around the upper portion of the stomach
* No cutting or stapling of stomach
* Can be adjusted
* Average weight loss 36-38% of excess weight at 2-3 years.
75
Potential Complications – Lap Band
* Nausea / Vomiting
* GE reflux
* Band slippage / pouch dilation
* Stoma obstruction
* Constipation, diarrhea, dysphagia, leaking/twisted port, and band erosion are possible
76
Gastric Sleeve
* Isolates a small section of the stomach for processing food, limiting the size of meals to approximately one ounce after surgery
* Decreases levels of an appetitestimulating hormone called ghrelin -- so people feel less hungry and eat less
* Considered “less radical”
* Lose approximately 50%+ of excess weight
* 85% of stomach taken out
77
Potential Complications - Gastric Sleeve
* Infection around incisions
* Abd hernias (less with laparoscopy)
* Nutritional deficiencies (not as much as other bariatric types)
* Obstruction or leaking at staple line
* Food intolerance (ie. Lactose intolerance)
* Dumping syndrome (not as much as other bariatric types)
78
Roux-en-Y (Gastric Bypass)
* Restrictive and Malabsorptive
* Most of the stomach and part of the small intestine are bypassed
* Stomach is stapled to create a smaller pouch. Part of the jejunum is attached to the stomach pouch
* Eat less and absorb less nutrients and calories
* Average loss of 70-80% of excess weight at two years.
79
Potential Complications – Roux-en-Y
* Infection around incisions
* Abd hernias (less with laparoscopy)
* Gallstones
* Nutritional deficiencies
* Obstruction or leaking at staple line
* Food intolerance (ie. Lactose intolerance)
* Dumping syndrome
80
GI Instruments
81
Pediatric GI surgeries
* Laparoscopic Endo-rectal pull through
* Hirschsprung's disease- swollen colon
* Diaphramatic Hernia
* one or all organs above diaphram
* Omphalocele
* organs outside in a sac (peritoneum)
* no belly button
82
Accessory organs of digestion
* Liver
* Pancreas
* Gall Bladder
* Duct system, aka “biliary tree”
* Nondigestive organ:
* Spleen
83
Liver anatomy
* Largest gland in the body
* (Average weight: 3#--healthy liver)
* Location: right subcostal region
84
Lobes of the liver
* Right Lobe- can see
* Left Lobe- can see
* Caudate Lobe- posterior surface of the right lobe, actually part of right lobe
* Quadrate Lobe-"
85
Ligaments of the liver
* Coronary ligament (top of liver, joins liver to diaphragm)
* Ligamentum Teres: AKA round ligament
* \* Falciform ligament\*
* holds weight of liver, main support
* separates rt and lft lobes
86
Adnexa (think neighbor: near or around)
* Diaphragm: covers superior aspect of liver
* Visceral peritoneum: covers inferior aspect of liver
* Glisson’s Capsule: surrounds liver
* like saran wrap in a meat package. Shiny, has own nerve supply
87
Why is the liver so odd? “The Circulatory Answer”
* The liver gets its blood from TWO sources!
* Nifty but hard to understand, so we will devote several more slides to “the circulatory answer”
88
Dual Blood Supply, part 1
* **Hepatic Artery:**
* “conventional” blood supply
* Supplies one third to one fourth of oxygen to liver, and less than one third of total blood volume
* average volume: 300ml/minute--lots of blood!
* branching that came off the aorta
* **not main source of blood**
89
Dual blood supply, part 2
* **Hepatic portal vein-- not artery, no valves, worried about bleeding**
* **“Exceptional”** blood supply
* majority of blood supply and oxygen supply
* Unlike most veins, portal vein is valveless
90
* C= hepatic artery
* D= Hepatic portal vein
91
Four major vessels which lead into the hepatic portal vein
* Inferior Mesenteric Vein
* Splenic Vein
* Superior Mesenteric Vein
* Gastric Vein
Coming from stomach and intestines
92
Portacaval Anastomoses
* Definition: Where regular veins become valveless as they approach the hepatic portal vein or its 4 major contributing veins (above)
* As a ST know pretty big vein with no valves-- should have suction ready, vascular set, clips
93
IF THE HEPATIC PORTAL VEIN BRINGS BLOOD TO THE LIVER, WHAT STRUCTURE(S)\* DRAINS BLOOD FROM THE LIVER?
* Hepatic Vein
* drainage back to Vena Cava
94
Dual blood supply and single\* venous exit
* Creates a pressure gradient
* Approximately 450 mls of “extra” blood in the liver at any given time-- lots of blood, heavy
95
Anomalous Location
* supplied from the bottom and drained from the top
96
Nerovascular bundle/pedicle
* Where vein, artery, and nerve come out the same place
97
Microanatomy of the liver
* **Functional unit of the liver: lobule**
* 50,000 to 100,000 lobules to a liver
* Anatomic features of the lobule:
* **Canaliculi: tiny endings of bile ducts**
* Single central venules: lead to the hepatic vein
* Sinusoids: thin-walled “tributaries” of the venules
98
2 types of liver cells
* **Hepatocytes: the main type of liver cell**, which:
* produce bile
* pick up nutrients from blood
* store fats and fat soluble vitamins
* Detoxify/metabolize drugs, nutrients and waste products
* **Kupffer cells--way less of these, specialized job**
* ****Specialized **phagocytes**
* **Remove bacteria and debris from blood**
* especially important for removing enteric bacteria from hepatic portal blood
99
3 main functions of the liver
* Metabolic
* Excretory- produces bile
* Storage- fats & sugars
100
Metabolic Functions
* **Anabolism** (synthesis)
* Plasma proteins
* Transfer proteins for hormones, vitamins, nutrients
* Cholesterol/bile salts
* Partial synthesis of coagulation factors
* **Catabolism** (aka deconstruction)
* nutrients broken down into: triglycerides, cholesterol, proteins, carbohydrates
* drugs
* hormones
* vitamins
* other active metabolites
101
Storage function of liver:
* Carbs
* Lipids
* Triglycerides
* Cholesterol
102
Excretory Function of liver
* Bile formation
* 600-1200ml produced daily--a lot
* Contents of bile
* bile salts
* The only ingredient of bile with a digestive function (break up fats)
* water
* electrolytes
* cholesterol
* other organic waste products
* bilirubin
103
Trace the flow of bile:
* Manufacture site: hepatocytes
* canaliculi
* bile ductules
* bile ducts
* L&R hepatic ducts
* Common hepatic duct
* Cystic duct
* Gallbladder (bile is concentrated here)
* Common bile duct
* Ampulla of Vater\*
* Sphincter of Oddi\*
* Duodenum\*
104
Jaundice
* Aka icterus
* Caused by oversaturation of blood with bilirubin (bile pigment)
* Named for yellow color of tissues
* Seen prominently and first in sclera of eyes
* **A SYMPTOM**, not a specific disorder
105
Conditions which produce jaundice
1. Excessive destruction of RBC’s
1. not necessarily something wrong with liver
2. Impaired uptake of bilirubin by liver
3. Decreased conjugation (making it to be excreted) of bilirubin by liver
4. Obstruction of bile flow in bile ducts (stone, stricture)
106
Classifications of Jaundice
* Prehepatic
* Intrahepatic
* Posthepatic
107
Prehepatic Jaundice
* Often caused by hemolysis of RBC’s resulting from:
* Hemolytic blood transfusion reaction
* Spherocytosis- congenital disorder
* Hemolytic infant disorders
* Usually mild
* Normal appearing stool and urine
108
Intrahepatic Jaundice
* Cause is within the liver:
* Hepatitis
* Cirrhosis
* Liver cancer
* Urine is dark, stool is light
109
Posthepatic/Cholestatic Jaundice
* Causes result in a backup of bile between liver and small intestine:
* cholelithiasis, cholecystitis, bile duct strictures, tumours of the bile ducts or pancreas
* Urine is dark, stool clay colored
* Patient complains of pruritis
110
Portal Hypertension
* Abnormally high blood pressure in the portal venous system
* Like jaundice, a symptom, not a specific disorder
* Caused by conditions which impede blood flow through portal system or vena cava:
* Viral hepatitis, parasitic infection, thrombosis, inflammation, or fibrosis of the sinusoids in the liver (most commonly caused by cirrhosis of the liver)
111
PH Complications
* Long term PH may lead to:
* Portosystemic shunts
* Splenomegaly
* Ascites
* Hepatic encephalopathy
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Portosystemic Shunts, aka **Varices**
* Develop between portal system and systemic veins due to pressure of portal system
* Distended, tortuous, may easily rupture
* **Vomiting blood from esophogeal varices: most common clinical manifestation of PH.**
* \* In ascites, may appear as Caput Medusae
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Splenomegaly
* PH results in shunting of blood to splenic vein
* Spleen begins to enlarge, and develops hypersplenism
* Decrease in formed elements of blood (RBCs, WBCs, Platlets)
* Anemia, thrombocytopenia, leukopenia
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Ascites
* ASCITES MAY BE CAUSED BY OTHER CONDITIONS ASIDE FROM PH. WE WILL LIST IT HERE AS A POSSIBLE LONG-TERM DEVELOPMENT OF PH, AND GO OVER IT IN DETAIL VERY SOON.
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Hepatic Encephalopathy
* Buildup of ammonia and other toxins result in brain function alteration
* Early sign: asterixis, or flapping tremor
* (Portal blood dirty and backing up)
* affects motor nerves
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Treatments for PH
* Portacaval shunts
* beta blockers
* variceal ligation
* esophageal balloons
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Portacaval Shunts
* A surgical venous shunt between portal and systemic circulation designed to result in decreased pressure in the portal system
* need vascular set
* don't do many
* aleviate pressure
* dirty blood
* bypass liver
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Beta Adrenergic Blockers decrease:
* heart rate
* myocardial contractility
* blood pressure--all BP
* myocardial O2 demand
* (non-invasive)
* person will have less energy, less ambulatory
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Variceal Ligation
* Surgical ligation of varices to help prevent rupture
* Will not help reduce PH
* Most often done on **esophogeal** varices, usually through use of a band
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Esophogeal Balloons
* Like ligation, designed to help prevent rupture
* Varicies will eventually re-enlarge
* Will not reduce PH
* (end-stage procedure most of the time)
* increase lumen of vessel
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Ascites & Clinical manifestations
* Like jaundice and PH, **a symptom and not a specific disease**
* A type of “third-space” disorder, particular to the abdomen
* Most common cause: cirrhosis
* Other causes:
* Late-stage hepatitis,renal failure; constrictive pericarditis; abdominal malignancies; nephrotic syndromes; malnutrition
* Clinical Manifestations of Ascites:
* Weight gain
* Abdominal distention
* Increased abdominal girth
* Dyspnea caused by large volumes of fluid in abdomen displacing diaphragm and decreasing lung capacity (don't put pt. in Trendelenburg)
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Hepatitis
* Most commonly caused by one of several strains of hepatitis viruses
* Means “inflammation of the liver”
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Hepatitis A
* Formerly called “infectious hepatitis”
* Transmission: fecal/oral
* Usually mild, does not cause chronic or carrier state
* Vaccine exists
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Hepatitis B
* Transmission: parenteral or sexual
* Produces both chronic and carrier states
* Vaccine available
* Most common viral hepatitis risk to healthcare workers
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Hepatitis C
* Usually transmitted parenterally; rare cases of sexual transmission have been reported
* Usually less severe than HBV
* May produce chronic and carrier states
126
Hepatitis D
* Route of transmission may be parenteral, sexual, or fecal-oral
* A co-infection: depends on person being already infected with HBV
* No carrier state
* HDV does have a chronic state
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Hepatitis E
* Transmission is fecal-oral
* Rare in US
* May be fatal to pregnant patients
* No chronic or carrier state
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Hepatits Facts:
* **Chronic hepatitis is a causative factor for cirrhosis and primary hepatocellular cancer**
* Autoimmune hepatitis exists but is poorly understood
* The hepatitis virus continues to mutate so some clinicians refer to “Hep G” or “Hep X”…meaning the next strain they think they may have isolated
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Cirrhosis
* AKA: end stage liver disease
* Like PH and jaundice, a condition and not a specific disease
* Characterized by diffuse fibrosis and nodular regeneration between fibrous bands; results in a “cobbly” appearance
* **Incurable except by liver transplant**
* Develops slowly over a period of years
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Causes of Cirrhosis
* Hep B, C, D
* Alcohol abuse
* Hereditary metabolic disorders
* Autoimmune disorders
* Drug abuse
* Biliary obstruction- not that commom
* Other:
* HBV,HCV, and HDV combined with alcohol abuse account for the causation of 65% of cirrhosis cases
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Clinical Manifestations of Cirrhosis
* Early: – Weight loss, weakness, diarrhea, anorexia(don't feel hungry), jaundice, abdominal pain, ascites
* Late: – PH, splenomegaly, ascites, varices, hepatic encephalopathy, and all related complications In men: testicular atrophy, gynecomastia
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Hepatic Neoplasms
* Primary Tumors
* Benign
* Malignant
* Secondary Liver Tumors--matastises
* Note: diagnosis of type of tumor cells is difficult in the liver. The diagnostic method of choice is often a liver biopsy.
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Primary Tumors
* Benign
* Cavernous Hemangioma-operate on-bloody vascular
* Hepatocellular Adenoma-resect
* Malignant--rare 2% of cancer in U.S.
* Hepatocellular carcinoma
* Cholangiocarcinoma
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Secondary Liver Tumors
* More common than primary liver tumors
* Often related to primary tumors found in:
* GI tract
* Lungs
* Breast
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Liver resection
* May use cryotherapy or radiotherapy for very small tumors
* Entire lobe may be resected for CIS (carcinoma in-situ--no metasteses) or metastasis
* Open surgery, very vascular
* Full resection= liver transplant
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Gallbladder Anatomy
* Greenish, about 10cm long
* Muscular, inner layer has rugae like stomach (can expand and contract)
* Located under ventral surface of liver (right lobe)
* Covered by visceral peritoneum (lesser omentum)
* Dome-shaped inferior portion: fundus
* “Reservoir” near cystic duct: Hartmann’s pouch
* Blood supply and bile drainage may include anomolies
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139
Biliary Tree Anatomy
* Superior to inferior
* Right and left hepatic ducts
* Common hepatic duct
* Cystic duct
* Common bile duct
* Ampulla of Vater
* Sphincter of Oddi
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Gallbladder Physiology
* Stores bile
* Also concentrates bile, up to 10 its strength when excreted by liver
* Bile only flows into the duodenum when the gall bladder contracts and the Sphincter of Oddi opens
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Gallbladder Pathophysiology
* Cholelithiasis
* Cholecystitis
* Primary Cancer (Cholecarcinoma)
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Cholelithaisis
* Aka gallstones
* Extremely common; incidence is rising
* 3 times more common in women than men
* Two types:
* Cholesterol stones: 75% of gallstones
* Pigmentatry, remaining 25%, made of calcium bilirubinate
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Cholecystitis
* AKA inflammation of the gallbladder
* May be a result of:
* Cholelithaisis; obstruction from gallstones or strictures in the common bile duct; gallbladder infection
145
Clinical Manifestations of all gallbladder pathophysiology
* Right upper quadrant pain
* Abdominal pain
* Heartburn
* Flatulence
* Jaundice (sometimes)- if gallstone is plugging up duct
* Epigastric discomfort
* Food intolerance
146
Gallbladder Cancer
* Very rare
* Prior cholelithaisis increases risk
* symtoms are the same as clinical manifestations listed before
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Triangle of Calot
* cystic artery
* cystic duct
* common hepatic duct
148
Labeled Pancreas
Surgical Procedures I
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