Gallstones

Types of gallstones:

Cholesterol stones
Pigment (brown/black) stones and
Mixed stones

Pathogenesis

Cholesterol stone:

Cholesterol is synthesized in liver. Its solubility is determined by relative concentration of cholesterol, bile salts and lecithin. Altered levels of cholesterol, lecithin, and bile salts in bile reduces the micelle concentration in the bile leading to precipitation of insoluble cholesterol, hence the stone formation.

Factors altering the cholesterol to bile salt ratio are obesity, high-calorie diets and certain medications. These increase the secretion of cholesterol and supersaturate the bile, increasing the lithogenicity of bile.

Pigment stone:

Types- black and brown

Black stones-

composed of insoluble bilirubin pigment polymer mixed with calcium phosphate and calcium bicarbonate. Black stones accompany hemolysis (hereditary spherocytosis or sickle cell disease)

Brown stones-

composed of calcium bilirubinate, calcium palmitate, calcium stearate and cholesterol. It is rare in gall bladder and usually forms in bile duct and are related to bile stasis and infected bile. Deconjugation of bilirubin deglucuronide by bacterial beta- glucuronidase causes insoluble unconjugated bilirubinate to precipitate leading to stone formation.

Brown stones are also associated: Foreign body within the bile duct (e.g. endoprosthesis)

Parasites (like Clonorchis sinensis and Ascaris lumbricoides)

Cholesterol stone

Pigment stone

Clinical presentation:

Patient may be asymptomatic or presents with features of its complications.

Effects and complications of gallstones

In the gall bladder

Biliary colic

Acute cholecystitis

Chronic cholecystitis

Empyema of the gall bladder

Mucocele

Perforation

b. In the bile ducts

Biliary obstruction

Acute cholangitis

Acute pancreatitis

c. In the intestine: Gallstone ileus ( intestinal obstruction)

Diagnosis:

Based on history, physical examination and confirmatory radiological studies such as transabdominal USG and radionucleide scans.

T/T

Asymptomatic gall stone: observation

If symptomatic or complication of gallstones: cholecystectomy

Prophylactic cholecystectomy is done in:

diabetic pt

those with congenital hemolytic anaemia

those who undergo bariatric surgery for morbid obesity

Acute Cholecystitis

Definition: acute inflammation of the gallbladder, usually caused by cystic duct obstruction by gallstones.

Presentation

Biliary colic: severe right upper quadrant pain associated with nausea and vomiting. Pain may radiate to the chest. Pain is usually severe and last for minutes or several hours. Frequently, pain starts during the night, waking the patient. Dyspeptic symptoms may coexist and be worse after the attack.

Right upper quadrant (RUQ) tenderness on palpation that is exacerbated during inspiration: Murphy’s Sign.

Low-grade fever and leukocytosis

Murphy’s sign

Investigations

1. USG: reveals presence or absence of gallstone and thickening of the gall bladder wall

2. Plain X-ray abdomen : 10% of gallstone are radiopaque

3. Blood: Leucocytosis

Moderately elevated liver function

4. Radioisotope scanning

Allows visualisation of biliary tree and gall bladder. GB is visualised within 30min of isotope injection. Non-visualization of GB is suggestive of Acute cholecystitis.

USG findings in Ac. Cholecystitis

Treatment

After the diagnosis of acute cholecystitis is made, IV fluids, antibiotics, and analgesia should be initiated.
Antibiotics should cover gram-negative aerobes as well as anaerobes.
Cholecystectomy is the definitive treatment for patients with acute cholecystitis.
Early cholecystectomy performed within 2 to 3 days of presentation (if patients fail initial medical therapy and require surgery during the initial admission)
If early cholecystectomy not indicated: Interval or delayed cholecystectomy that is performed 6 to 10 weeks after initial medical therapy.

Cholecystectomy: open or laparoscopic

Complications

i. Empyema of the gall bladder

ii. Gangrene of the gallbladder

iii. Perforation and peritonitis

iv. Fistula formation and gallstone ileus (small bowel obstruction by a large gallstone

Chronic Cholecystitis

Defnition: ongoing chronic inflammation of the gallbladder usually caused by gallstones

Micro: chronic inflammation and Rokitansky-Aschoff sinuses

Late complication: calcification of the gallbladder ("porcelain gallbladder")

T/t: Cholecystectomy

Rokitansky-Aschoff sinuses

Porcelain gallbladder

Acalculous Cholecystitis

Inflammation of the gall bladder in the absence of the stones.
Seen particularly in patients recovering from major surgery, trauma and burns.
Clinical picture similar to calculous cholecystitis.

T/t: Cholecystectomy

Empyema of the gall bladder

Definition: Presence of pus in the gall bladder

Etiology

Sequel of acute cholecystitis

Infected mucoecele

c/f

Fever, toxicity

Pain and tenderness in Rt. Hypochondrium

The wall may become necrotic and perforate with the development of localised peritonitis

Investigation

1. USG abdomen

2. Blood: leucocytosis

Treatment

Drainage and, later, cholecystectomy

Mucocele

A nontender, palpable gall bladder results from complete obstruction of the cystic duct with resbsorption of the intraluminal bile salts and secretion of uninfected mucus by the gall bladder epithelium

Mucocele of gall bladder