Gallstones and pancreatitis

Gallstones

• Only 10–15% are radio-opaque; ultrasound is the investigation of choice (echogenic focus with acoustic shadow), including in pregnancy.
• Most stones are silent and need no treatment. Long-standing stones cause chronic inflammation, the main link to gallbladder carcinoma (a porcelain gallbladder carries a higher risk).

Biliary colic and acute cholecystitis

• Biliary colic: a stone temporarily blocks the cystic duct: constant RUQ or epigastric pain for over 30 minutes to hours, radiating to the right scapula, after fatty meals; no fever, no peritonism, normal blood tests. Analgesia with an NSAID (diclofenac) is very effective, adding an antispasmodic such as hyoscine if needed; then elective laparoscopic cholecystectomy.
• Acute cholecystitis: persistent cystic duct obstruction causes chemical then bacterial inflammation (*E. coli*, *Klebsiella*, *Enterococcus*). RUQ pain over 24 hours, fever, Murphy sign (inspiratory arrest on RUQ palpation), raised white count and CRP, mild rise of ALP.
• Ultrasound: thick wall (over 3 mm), pericholecystic fluid, stones, sonographic Murphy sign; HIDA scan if doubtful.
• Treatment: fluids, analgesia, IV antibiotics, early laparoscopic cholecystectomy (within a week, ideally 72 hours); percutaneous cholecystostomy if unfit.
• Complications: empyema, gangrene and perforation (elderly, diabetics), cholecystoenteric fistula with gallstone ileus (Rigler triad: small bowel obstruction, pneumobilia, ectopic stone, usually at the terminal ileum), Mirizzi syndrome (a stone in Hartmann's pouch compresses the common hepatic duct, causing jaundice), mucocele (distended, non-tender).
• Acalculous cholecystitis in the critically ill (ICU, burns, sepsis, TPN): high mortality; cholecystostomy.

Bile duct stones and cholangitis

• Common bile duct stones (10–15% of gallstone patients) cause fluctuating painful jaundice, pancreatitis or cholangitis.
• Ascending cholangitis: Charcot triad (fever with rigors, jaundice, RUQ pain); Reynolds pentad adds hypotension and confusion. IV antibiotics and urgent biliary decompression by ERCP (sphincterotomy, stone extraction, stent); PTC if ERCP fails.
• MRCP diagnoses duct stones non-invasively; EUS is very sensitive; ERCP is therapeutic. Cholecystectomy follows duct clearance.

Laparoscopic cholecystectomy

• Calot triangle: cystic duct, common hepatic duct and inferior surface of the liver, containing the cystic artery.
• Critical view of safety: the hepatocystic triangle cleared of fat, the lower third of the gallbladder off the liver bed, and only two structures (cystic duct and artery) entering the gallbladder.
• Complications: bile duct injury (most serious, 0.3–0.5%), bile leak (cystic stump, ducts of Luschka), bleeding, retained stones, right hepatic artery injury, port-site hernia.

Acute pancreatitis

• Causes: gallstones (commonest in Pakistan and worldwide) and alcohol (together about 80%); post-ERCP; hypertriglyceridaemia (over 11 mmol/L; type I hyperlipidaemia from lipoprotein lipase deficiency with eruptive xanthomas and chylomicrons); hypercalcaemia; drugs (azathioprine, valproate, thiazides, furosemide, steroids, oestrogens); trauma; mumps, Coxsackie, CMV, *Ascaris*; scorpion sting; autoimmune (IgG4); pancreas divisum; hypothermia; idiopathic.
• The common first event: trypsinogen is activated to trypsin inside acinar cells (blocked duct pressure, calcium overload, alcohol), which activates other enzymes (phospholipase A₂, elastase, lipase) and causes autodigestion, inflammation, fat necrosis and haemorrhage.
• Features: sudden severe epigastric pain radiating to the back, eased by sitting forward, vomiting, tachycardia; Grey Turner sign (flank bruising) and Cullen sign (periumbilical) from retroperitoneal haemorrhage.
• Diagnosis needs two of: typical pain, amylase or lipase over 3 times normal, imaging. The pair of enzymes is the most valuable test; lipase is more specific and stays raised longer; amylase may be normal late or with very high triglycerides (and a high amylase in mumps can be salivary). Enzyme levels do not reflect severity.
• Ultrasound in everyone (gallstones). Contrast CT is not routine early; do it after 72 hours if the diagnosis is uncertain or the patient deteriorates (necrosis).
• Severity: Revised Atlanta: mild (no organ failure), moderately severe (organ failure under 48 hours or local complications), severe (organ failure persisting beyond 48 hours). Glasgow (Imrie) score of 3 or more within 48 hours (PaO₂ under 8 kPa, age over 55, white count over 15, calcium under 2 mmol/L, urea over 16 mmol/L, LDH over 600 or AST over 200, albumin under 32 g/L, glucose over 10 mmol/L); CRP over 150 mg/L at 48 hours; APACHE II 8 or more. Severe disease shows hypocalcaemia (fat saponification), hyperglycaemia, rising haematocrit and urea, hypoxia.
• Management: goal-directed IV fluids (Hartmann's, avoiding overload), analgesia (opioids are fine), oxygen, urine output monitoring, early enteral feeding (better than TPN), no prophylactic antibiotics, ICU for organ failure. Gallstone pancreatitis: urgent ERCP for cholangitis or persistent obstruction; cholecystectomy in the same admission for mild disease.

• Infected necrosis (gas on CT, deterioration in weeks 2–4): carbapenem, then the step-up approach (percutaneous or endoscopic drainage, then minimally invasive necrosectomy, ideally after 4 weeks). Other complications: splenic artery pseudoaneurysm bleeding, splenic vein thrombosis, left pleural effusion, ARDS, AKI, DIC.

Chronic pancreatitis

• Alcohol is the commonest cause. Triad: recurrent epigastric pain, steatorrhoea (exocrine failure) and diabetes (endocrine failure), with calcification on X-ray or CT and low faecal elastase.
• Fat malabsorption causes deficiency of the fat-soluble vitamins A, D, E and K; B12 absorption also falls because pancreatic proteases are needed to free B12 from R-binder.
• Enzyme replacement with meals, analgesia, abstinence; endotherapy or surgery for duct strictures and stones; increased pancreatic cancer risk.

Obstructive jaundice

• Causes: in the lumen (duct stones, the commonest; *Ascaris*), in the wall (benign strictures, PSC, cholangiocarcinoma, choledochal cyst, biliary atresia), outside (carcinoma of the head of pancreas, periampullary tumours, porta hepatis nodes, Mirizzi, pancreatitis).
• Courvoisier law: painless jaundice with a palpable, non-tender gallbladder is unlikely to be due to stones. Gallstones cause years of chronic inflammation that leaves the gallbladder fibrotic and shrunken, so it cannot distend; a malignant obstruction of the lower duct develops in a previously healthy, distensible gallbladder.
• Investigation sequence: LFTs, ultrasound (are ducts dilated, at what level?), MRCP or pancreatic-protocol CT, EUS, then ERCP (lower obstruction) or PTC (hilar).
• Before operating on a jaundiced patient: IV vitamin K (no bile salts to absorb it; FFP if urgent), hydration and urine output to prevent hepatorenal failure from endotoxaemia, antibiotic cover for cholangitis, nutrition, care with drug doses.
• In cirrhosis, hepatic stellate (Ito) cells, which normally store vitamin A in the space of Disse, become myofibroblasts and lay down the collagen that, with regenerative nodules, defines cirrhosis.

Remember Where the stone stops decides the disease: cystic duct for colic and cholecystitis, common duct for jaundice and cholangitis, ampulla for pancreatitis.

Exam trap Charcot triad (fever with rigors, jaundice, RUQ pain) means cholangitis and urgent ERCP.

Exam trap A pseudocyst forms after 4 weeks and has a fibrous wall without epithelium; enzyme levels do not measure severity.

How FCPS asks about this

• First event in acute pancreatitis: trypsinogen activated inside acinar cells; lipase and amylase together confirm.
• Severity: Glasgow 3 or more, CRP over 150 at 48 hours, persistent organ failure over 48 hours; no prophylactic antibiotics; feed enterally.
• Recurrent pancreatitis with eruptive xanthomas: lipoprotein lipase deficiency.
• Courvoisier law: stones leave a fibrotic gallbladder that cannot distend.
• Pigment stones: black in haemolysis, brown in infected ducts.
• Gallstone complications: Mirizzi syndrome, gallstone ileus with pneumobilia, empyema.
• Jaundiced patient before surgery: IV vitamin K and hydration; ultrasound first, including in pregnancy.