Cholelithiasis (Gallstones)

Epidemiology

• Around 10-15% of the adult population (in the developed world) will develop gallstones.  The majority are asymptomatic- only 1-4% develop symptoms.  However, symptomatic gallstones often present recurrently and can be in danger of causing serious complications (see below).  As a result, all patients with symptomatic gallstones should be offered cholecystectomy.

Pathophysiology/Aetiology

• Occur when there is dysequilibrium of the chemical components of bile which results in the formation of a stone.
  • Most commonly (80%) are cholesterol stones; the remainder are either calcium, bilirubin or pigment stones (the latter two are usually secondary to haemolysis (there are also mixed stones).
• Gallstones are known to be more common in women, obese individuals, older individuals, pregnancy, diabetics, following weight loss etc
• The OCP increases the risk of gallstones
• More common in iron deficient anaemia
• Also often present in carcinoma of the gallbladder

Potential Complications of Gallstones

• Biliary colic
• Jaundice
• Acute cholecystitis
• Ascending cholangitis
• Biliary empyema
• Pancreatitis
• Gallstone ileus
• Perforated gallbladder/biliary tree

Presentation

• As mentioned, some patients may have gallstones diagnosed as a coincidental finding and the patient may be completely asymptomatic

• These do not require treatment but a watchful waiting approach should be used in case things are worse.

• In symptomatic patients, symptoms can often be precipitated by a fatty meal.  A ‘gallbladder attack’ involves
  • Stady pain in the right upper abdomen that has peaks in severity (colic) and can last from 30 mins to usually <8 hours.
  • Biliary colic does not present with any RUQ examination, fever or jaundice

Investigations and Management

• Bloods: LFTs (Alk Phos and bilirubin are classically raised in gallstone cholecystitis; clotting screen (liver is the site of production for clotting factors 2, 7, 9 and 12)
• Ultrasound is the first line investigation of gallstones
  • The bile duct (common) should be <7mm wide, there should be no thickening of the gallbladder wall.
• MRCP and ERCP are indicated only really when there is associated jaundice, deranged LFTs, a significantly dilated bile duct on USS; recent pancreatitis/cholangitis etc
  • MRCP is the most effective way of imaging these patients in whom you are not fully certain require cholecystectomy management e.g. deranged LFTs but normal USS or vice versa.
  • ERCP is the most common method of both identifying cholelithiasis but, more importantly now, it is used to treat gallstones in the acute setting:
    • NB ERCP is an invasive procedure that carries 1% risk of perforation (and usually subsequent mortality).  It also has risks of bleeding, pancreatitis etc
    • As such, a clotting screen must be done prior to investigation and, ideally, anticoagulants should be stopped up to a week before the procedure.
    • Post-ERCP, amylase levels should also be measured.
    • Where possible, stone extraction and sphincterotomy are performed.  Otherwise, stenting is an alternative method.
  • If ERCP is unsuccessful, the patient will require surgery for the removal of the gallbladder if they are fit to do so
• Cholecystectomy (laparoscopic) is the mainstay of treatment for the majority of chronic, known gallstones who are at low risk and who are symptomatic.