Cholelithiasis (calculi or gallstones)
ANATOMY OF GALLBLADDER
- A pear-shaped, hollow, saclike organ, 7.5 to 10 cm (3-4
inch) long, lies in a shallow depression on the inferior
surface of the liver, , bound by vessels, connective
tissue, and lymphatics. It has four regions: the fundus,
body, infundibulum, and the neck.
- The capacity of the gallbladder is 30 to 50 ml of bile.
- The gallbladder is connected to the common bile duct
by the cystic duct .
PHYSIOLOGY OF GALLBLADDER
- It acts as a storage depot for bile.
- Between meals, when the sphincter of Oddi is closed, bile produced by the
hepatocytes enters the gallbladder
- During storage, a large portion of the water in bile is absorbed through the walls
of the gallbladder, so that gallbladder bile is times more concentrated than that
originally secreted by the liver.
- When food enters the duodenum, the gallbladder contracts and the sphincter
of Oddi relaxes, allowing the bile to enter the intestine.
- This response is mediated by secretion of the hormone cholecystokinin pancreozymin (CCK-PZ) from the intestinal wall.
Bile composition
- Bile is a combination of cholesterol, phospholipids (principally lecithin), bile salts
(chenodeoxycholic acid and cholic acid) and water. Bile also contains conjugated
bilirubin.
Function :
- Bile juice emulsifies fats and breaks them down into small particles.
- Bile juice helps in the absorption of fat-soluble vitamins.
- Bile also serves as the route of excretion for bilirubin, a by-product formed
during the destruction of red blood cells.
Cholelithiasis (calculi or gallstones)
- pathological conditions which are solid masses formed from bile precipitates.
These “stones” may occur in the gallbladder or the biliary tract (ducts leading
from the liver to the small intestine).
- Uncommon in children and young adults
- Increasingly prevalent after age 40.
PATHOPHYSIOLOGY :
Gallstones due to imbalance rendering cholesterol & calcium salts insoluble
Pathogenesis involves 4 stages:
1- Increased cholesterol synthesis in the liver ↓
1- Supersaturation of bile with cholesterol ↓
2- Formation of precipitates: is accelerated cholesterol crystal nucleation. ↓
3- Gallstones (Cholelithiasis)Stone growth. ↓
4- Inflammatory changes (Cholecystitis).
Types
There are 3 types of gallstones: cholesterol and pigment stones and mixed .
1- Cholesterol stones
Large,Often solitary,Yellow,white or green,Made primarily of hardened
cholesterol.
Risk factors:
predominantly found in women and obese people , pregnancy, as well as an
increase with age. Family history, low dietary fiber.
2- pigment stones
- Small, multiple ,vFriable,Irregular,Dark ,Made of bilirubin and calcium salts,
Less than 20% of cholesterol , The exact cause is not known.
Risk factors: ( haemolytic anaemias , Liver cirrhosis , Biliary tract infections
,Ileal resection)
3- Mixed stones are the most common type.
Multiple , Faceted , Consist of:Calcium salts ,Pigment,Cholesterol (30% - 70%)
Risk factors:
80% - associated with chronic cholecystitis
Risk factors ( causes ) :
- Age
The incidence of gallstone disease increases with age( Age over 40 years ).
- Drugs
Many drugs have been implicated in gallstone disease. The most common
offenders include ceftriaxone, clofibrate, oral contraceptives, estrogen
replacement,
progestogens, and octreotide.
- Gender
The prevalence of gallstones is higher in women than men. for this gender
difference is hormonal. Serum estrogen increases (especially during
pregnancy) promotes biliary cholesterol saturation and increased progesterone
may lead to inhibition of the contraction of the gallbladder.
- Obesity
Obesity is a significant risk factor for gallstone disease, especially in women.
Studies have demonstrated that overweight women with a body mass index
(BMI)
greater than or equal to 30 kg/m2 have double the risk of gallstone disease.
- Weight Loss
An increased risk of gallstone disease may be found among individuals who
undergo rapid weight loss on very low calorie diets. Gallstone formation is one of
the
most significant complications of voluntary weight loss plans.
- Hormonal therapy ,Diabetic persons ,Patients with gastro-intestinal
diseases.
CLINICAL MANIFESTATION:
- Epigastric distress or pain.
- Feeling of Fullness
- Abdominal distention
- Palpable abdominal mass
- Vague pain in the right upper quadrant of the abdomen
- Fever
- Constant pain, restless in all position
- Jaundice
- Biliary colic occurs when the gallbladder contracts following cholecystokinin
release by the duodenum but its outflow is obstructed with excruciating upper
right abdominal pain that radiates to the back or right abdominal pain and
radiates to the back or right shoulder, associated with nausea and vomiting and
is noticeable several hours after a heavy meal
- Acute cholecystitis If the stone remains impacted in the gallbladder out let, the
gallbladder wall becomes inflamed owing to the irritation of the concentrated bile
contained within it producing a chemical cholecystitis. The gallbladder fills with
pus, which is frequently sterile .
- Chronic cholecystitis This is almost invariably associated with the presence of
gallstones.Repeated episodes of inflammation result in chronic fibrosis and
thickening of the entire gallbladder wall, which may contain thick, sometimes
infected bile.
- Obstruction of the flow of bile into the duodenum results in Yellow color
skin and mucous membrane.
- Marked itching of the skin.
- Changes in urine and stool color
- A very dark colored urine.
- Vitamin deficiency(A,D,E, and K)
- If gallstone continues to obstruct the duct : Abscess ,Necrosis, Perforation,
Generalized peritonitis
Diagnosis
Laboratory Tests :
1- Biochemical tests of liver function are abnormal only when there are
complications of gallstones. In acute cholecystitis,
- there may be leukocytosis with a "left" shift.
- Persistently raised alkaline phosphatase is suspicious for choledocholithiasis.
Prothrombin time should also be checked in the presence of jaundice lest any
invasive procedure be required.
2- Blood tests Performed to look for signs of infection, obstruction, pancreatitis,
or jaundice
Radiological tests :
1- Ultrasound: this non-invasive technique gives three pieces of information:
− the presence of gallstones within the gallbladder, revealed as intensely
echogenic foci, which cast a clear acoustic shadow beyond them;
−the thickened wall of the gallbladder in acute or chronic inflammation;
− the diameter of the common bile duct which, if over 7 mm, is suggestive of the
presence of stones within. Unfortunately, ultrasound, like computed tomography
(CT), is unreliable in detecting stones in the bile ducts, especially at the lower
end where they are obscured by the overlying duodenal gas.
2- Plain abdominal X-ray, though rarely done these days, reveals radio-opaque
gallstones in only 10% of cases. These usually appear as rings due to calcium
deposited on a central translucent organic core. Occasionally, the gallbladder
may be seen to be calcified (‘porcelain gallbladder’).
3- Upper gastrointestinal endoscopy may be advisable to exclude an
associated peptic ulcer or hiatus hernia when there is any degree of uncertainty
in the clinical picture, even though gallstones have been noted on ultrasound.
4- CT Scan
Detection of calculous disease may employ computed tomography (CT)
scanning. CT scans are useful in demonstrating masses and dilated biliary ducts,
although
they are not as reliable for the diagnosis of calculous disease. Their principle use
is detection of the complications of gallstones such as pericholecystic fluid, gas in
the gallbladder wall, gallbladder perforation.
5- Magnetic resonance cholangiopancreatography (MRI)(MRCP) is a
relatively new application that utilizes MRI imaging with special software. It is
capable of producing images similar to ERCP without the accompanying risks of
sedation, pancreatitis, or perforation. MRCP is helpful in assessing biliary
obstruction and pancreatic ductal anatomy. It has been shown to be effective in
detecting gallstones and to evaluate the gallbladder for the presence of
cholecystitis.
6- (ERCP): endoscopic intubation of the bile ducts through the ampulla of
Vater is more invasive than MRCP, but in addition to visualizing the ducts and
contained stones it also permits their extraction, often after first carrying out a
diathermy sphincterotomy /balloon sphincteroplasty opening up the sphincter of
Oddi to facilitate instrumentation of the bile duct.
Complications :
- Often these complications are caused by inflammation, infection, or ductal
obstruction include: acute cholecystitis, choledocholithiasis, cholangitis,
pancreatitis, emphysematous cholecystitis, cholecystenteric fistulae, Mirizzi’s
syndrome, and porcelain gallbladder. The most serious late complication of this
condition is gallbladder carcinoma.
1) Acute Cholecystitis
- The most common complication of gallstones.it is usually caused by impaction
of a gallstone in the cystic duct. The entrapped bile in the gallbladder causes
damage to the gallbladder mucosa and inflammation of the gallbladder wall.
- clinical presentation is abdominal pain, right upper quadrant tenderness, fever
(usually <102°F), and modest leukocytosis (<16,000).
- Optimal management of a patient with cholecystitis is cholecystectomy.
2) Choledocholithiasis
- It is a complication that occurs when gallstones become displaced to the
common bile duct. Whereas gallstones in the gallbladder usually result in
relatively benign conditions such as recurrent biliary colic or acute cholecystitis,
choledocholithiasis can result in life-threatening conditions such as cholangitis
(bacterial infection of obstructed bile) or acute pancreatitis.
- is caused by the migration of cholesterol or black pigment stones from the
gallbladder into the common bile duct. Symptoms are related to the
rate of onset and degree of obstruction and the potential bacterial contamination
of the obstructed bile.
- If cholangitis develops, pain, jaundice, fever, mental confusion, lethargy and
delirium may all be present. Leukocytosis, elevations in bilirubin and alkaline
phosphatase, and positive blood cultures are also present.
3) Emphysematous cholecystitis
- occurs when the gallbladder wall is secondarily infected with gas-forming
bacterial microbes. The condition is more likely to occur in the elderly and
diabetic men, often occurring without stones.
- The clinical presentation is similar to acute cholecystitis but more toxic.
- Treatment requires antibiotics with anaerobic coverage and early
cholecystectomy.
4) Cholecystenteric Fistulae
- It forms when a large stone erodes through the gallbladder wall into an adjacent
loop of bowel. If the stone is very large (>25 mm), it may produce a small bowel
obstruction, known as gallstone ileus, found commonly in the terminal ileum.
- Treatment involves cholecystectomy and bowel resection.
5) Mirizzi's Syndrome
- is the result of a gallstone obstructing the cystic duct and resulting in
inflammation and compression of the common bile duct .
- The symptoms and signs involve jaundice and pain.
- The diagnosis and treatment involve ERCP .
6) Porcelain Gallbladder
A porcelain gallbladder is a rare complication in which there is intramural
calcification of the gallbladder wall, usually in association with gallstones.
- The treatment involves prophylactic cholecystectomy .
Complications of cholecystectomy
There are two special dangers after cholecystectomy, whether performed by
laparotomy or laparoscopy.
1 Leakage of bile. This may result from:
A . injury to bile canaliculi in the gallbladder bed of the liver;
B . injury to the common hepatic or common bile duct;
C . slipping of the ligature or clip from the cystic duct;
D . leakage from the common bile duct after exploration
2. Jaundice. This may be due to:
A . missed stones in the common bile duct;
B . inadvertent injury to the common bile duct;
C . cholangitis or associated pancreatitis.
Treatment
1- Non-surgical treatment of gallstones
• Gallstone dissolution. Because cholesterol is held in solution by bile salts,
dissolution of small cholesterol stones is possible by administering bile salts
orally in the form of chenodeoxycholic or ursodeoxycholic acid. This therapy may
be used
for small, non-calcified stones in a functioning gallbladder.
* Lithotripsy. Ultrasonic destruction of small stones as used in the renal tract
appeared to be an attractive option, but there is the problem of the passage of
small fragments of stone through the duct system that may cause biliary colic,
biliary obstruction and pancreatitis.
2- surgical treatment of gallstones
- Cholecystostomy : - Patients at high risk related to multisystem organ failure
- Severe pulmonary, renal, or cardiac disease
- Recent myocardial infarction
- Cirrhosis with portal hypertension
- Acalculous cholecystitis after severe trauma, burns, or surgery
- Empyema or gangrene of the gallbladder
- Subtotal cholecystectomy : - Severe inflammation renders identification of
the anatomy impossible, eg. Gangrenous cholecystitis
- Scarred partially intrahepatic gallbladder
- Severe cirrhosis and portal hypertension
- Open cholecystectomy
- Laparoscopic cholecystectomy has replaced the open procedure as the
treatment option of choice in all but a few instances.
- is a minimally invasive procedure in which the surgeon makes a few small
incisions in the abdomen and uses a small video camera to magnify the organs
of the abdominal cavity. Using the video monitor to guide his actions, the surgeon
identifies, isolates, and removes the gallbladder from its connections to the liver
and bile ducts through the laparoscope The procedure does not involve a large
abdominal incision and results in less pain, shorter hospital stay, and fewer days
missed from work. On occasion.