10.4 - Pathological Conditions of GI Accessory Organs Flashcards
Cause and Pathophysiology of Appendicitis?
Cause:
Obstruction of appendiceal lumen by:
- fecaliths (hardened stool)
- lymphoid hyperplasia (children/young adults)
- tumors or foreign bodies
Pathophysiology:
- Obstruction of appendiceal lumen = ↑ intraluminal pressure = impaired venous outflow = ischemia & bacterial overgrowth = necrosis = perforation (bc necrotic tissue is impaired) = peritonitis (leakage of non-sterile tissue in peritoneum )
Structural Changes and Clinical Significance of Appendicitis?
Structural Changes
- Edema & inflammation of appendix
- Necrosis & rupture of appendix = abscess formation or diffuse peritonitis
Clinical Significance:
Symptoms
- Periumbilical pain migrating to RLQ (McBurney’s point)
- nausea
- vomiting
-fever
- leukocytosis
Complications
- Rupture
- abscess
- peritonitis & sepsis
Management
- Surgical removal (appendectomy)
- Antibiotics
Cause and Pathophysiology of Gallstone (Cholelithiasis)
Cause
1) Cholesterol stones
-n Supersaturation of bile with cholesterol, stasis, & crystallization
2) Pigment stones
- Chronic hemolysis (e.g., sickle cell disease) or infection
3) Risk factors
- Obesity, rapid weight loss, pregnancy, female sex (estrogen-related), and genetic predisposition
Pathophysiology
- Imbalance in the composition of bile (cholesterol, bile salts, and lecithin) = precipitation of cholesterol or bilirubin
- Stasis of bile in the gallbladder promotes stone formation
- Obstruct the bile duct or cystic duct = cholecystitis
Structural Changes and Clinical Signs of Gall Stones
Structural Changes
- Formation of solid deposits (stones) in gallbladder or bile ducts = chronic irritation of gallbladder wall = thickening or calcification (porcelain gallbladder)
Clinical Significance
S&S
- Asymptomatic; Symptomatic = biliary colic (RUQ pain after fatty meals), nausea, and vomiting
Complications
- Cholecystitis, choledocholithiasis (common bile duct stones)
- pancreatitis
- cholangitis (swelling of bile duct system itself)
Management
- Symptomatic = cholecystectomy (surgical removal of gallbladder)
Cause of Cholescystitis
1) Gallstones (Calculous Cholecystitis)
- Majority of cases (~90%)
- Gallstones obstruct cystic duct = bile stasis & inflammation
2) Acalculous Cholecystitis
- Occurs in critically ill patients (i.e., sepsis or trauma
- Results from bile stasis, ischemia, & infection without gallstones
3) Other Causes
- Infections (e.g., Salmonella
- CMV in immunocompromised patients)
- Tumors obstructing bile flow
Pathophysiology of Cholecystitis
1) Obstruction
- Gallstone obstruction at cystic duct = stasis of bile = bile concentration = irritation of gallbladder lining
2) Inflammation
- Release of pro-inflammatory mediators (e.g., prostaglandins) = edema & mucosal damage
- Secondary bacterial infections (e.g., E. coli, Klebsiella)
3) Ischemia
- Prolonged inflammation = impaired blood flow = tissue ischemia = necrosis = gangrene
Structural Changes of Cholecystitis
1) Acute Cholecystitis
- Gallbladder wall thickening
- Mucosal damage with possible ulceration
- Pericholecystic fluid & abscess formation (severe cases)
2) Chronic Cholecystitis:
- Gallbladder wall fibrosis & calcification (“porcelain gallbladder”)
↓ gallbladder motility
Clinical Signs of Cholecystitis
Symptoms
- RUQ pain
- radiating right shoulder (referred pain: bc source of pain also causes nerve irritation)
- Fever
- nausea
- vomiting
- leukocytosis
- Positive Murphy’s sign (pain on deep palpation during inspiration)
Complications
- Empyema = Accumulation of pus in gallbladder
- Perforation = Rupture of the gallbladder = peritonitis
- Choledocholithiasis = gallstone obstruction of bile duct
Cholangitis = Bile duct infection
- Chronic inflammation ↑ risk of gallbladder cancer
Management
1) Supportive care
- IV fluids, antibiotics, pain medications (analgesics)
2) Surgical Intervention
- Cholecystectomy
- Laparoscopic (far more common) or open surgery
Causes and Pathology of Pancreatitis
Cause
- Acute = gallstones or alcohol use (most common), hypertriglyceridemia, trauma, infections, & drugs
- Chronic = chronic alcohol use, genetic predisposition (CFTR mutations), or recurrent acute pancreatitis
Pathophysiology
- Premature activation of pancreatic enzymes (e.g., trypsin) = auto digestion of pancreas = inflammation & necrosis follow
- Chronic pancreatitis = fibrosis & loss of exocrine/endocrine functions of the pancreas
Structural Changes and Clinical Significance of Pancreatitis
Structural Changes
1) Acute
- Edema, necrosis, hemorrhage, pseudocysts formation
2) Chronic
- Fibrosis, calcifications, dilated pancreatic ducts, loss of acinar & islet cells.
Clinical Significance
1) Acute symptoms
- Severe epigastric pain radiating to the back, nausea, & vomiting
2) Chronic symptoms
- Epigastric pain, malabsorption
- steatorrhea (fatty stools bc of issue of releasing pancreatic enzymes to support digestion)
- diabetes mellitus (bc of role pancreas plays in endocrine function)
3) Complications
- Pseudocysts, necrosis, infection, organ failure, & pancreatic cancer
4) Management
- Supportive care (IV fluids, analgesics)
- treat underlying cause (e.g., gallstone removal)
Causes and Pathophysiology of Pancreatic Cancer
Cause
1) Risk factors
- Smoking, chronic pancreatitis, family history, BRCA mutations, and diabetes mellitus
- Most are adenocarcinomas of pancreatic duct
Pathophysiology
- Oncogenic mutations (e.g., KRAS) =dysregulated cell proliferation = tumor growth disrupts pancreatic & adjacent organ functions = metastasis occurs early due to rich vascular and lymphatic supply
Structural Changes and Clinical Signs of Pancreatic Cancer
Structural Changes
- Tumor in the pancreatic head obstructing the bile duct = jaundice
- Fibrotic and infiltrative lesions spread locally & metastasize to distant organs (e.g., liver, lungs)
Clinical Significance
1) Symptoms
- Late presentation with vague symptoms
- Epigastric pain, weight loss, jaundice (duct obstruction), & new-onset diabetes
2) Prognosis
- Poor (advanced stage diagnosis)
3) Management
- Surgery (e.g., Whipple procedure) if localized
- Chemotherapy & palliative care
