36.2 Abdomen II: Gallstones, Cholecystitis, Choledocholithiasis and Cholangitis, Obstructive Jaundice, Liver (Cirrhosis, Portal Hypertension, Abscesses, Tumors and Hepatocellular Carcinoma), Pancreas (Acute and Chronic Pancreatitis, Pancreatic Cancer) and Spleen (Splenectomy, OPSI)

Why this area matters

Gallstone disease is the most common reason for elective abdominal surgery. In the Philippines, chronic hepatitis B drives a high burden of cirrhosis and hepatocellular carcinoma, and amebic liver abscess still occurs. Questions test the diagnostic pathway for jaundice and biliary pain, emergency decisions (cholangitis, severe pancreatitis, splenic injury) and the operation of choice.

Spectrum of Biliary Tract Disease

Biliary disorders stem predominantly from cholelithiasis (gallstones), which are classified into cholesterol stones ($80\%$, associated with the "4 Fs": female, fat, fertile, forty) and pigmented stones (black stones from chronic hemolysis/cirrhosis, brown stones from biliary infections and Clonorchis sinensis).

Obstructive jaundice and other biliary problems

• Workup:
  • conjugated hyperbilirubinemia with high ALP and GGT, dark urine, pale stools and pruritus;
  • ultrasound first, which shows dilated ducts and stones;
  • then CT (masses, staging), MRCP (non-invasive duct imaging), ERCP (diagnosis and therapy: stone extraction, stenting) or PTC.
• Causes:
  • choledocholithiasis;
  • carcinoma of the pancreatic head or periampullary region;
  • cholangiocarcinoma (a hilar Klatskin tumor; risk factors include liver flukes and primary sclerosing cholangitis);
  • benign strictures (after cholecystectomy injury);
  • choledochal cysts;
  • Mirizzi syndrome (a stone in the gallbladder neck compressing the common hepatic duct).
• Courvoisier law: a palpable, non-tender gallbladder with jaundice is unlikely to be from stones (the fibrosed gallbladder does not distend) and suggests malignancy.
• Preparing a jaundiced patient for surgery:
  • give vitamin K for the prolonged PT;
  • keep hydration (risk of hepatorenal failure);
  • treat cholangitis;
  • consider preoperative biliary drainage selectively.
• Gallstone ileus: a large stone erodes through a cholecystoenteric fistula and impacts in the terminal ileum. It shows Rigler triad (small bowel obstruction, pneumobilia, ectopic stone) and is treated by enterolithotomy.
• Gallbladder cancer: associated with gallstones and a porcelain gallbladder. It is often found incidentally or late.

Liver

• Cirrhosis and surgical risk:
  • Child-Turcotte-Pugh and MELD scores predict operative mortality;
  • elective surgery is avoided in Child C patients;
  • risks are bleeding, encephalopathy, ascites leak, infection and liver failure.
• Portal hypertension:
  • varices (banding, beta-blockers, vasoactive drugs), ascites and splenomegaly with hypersplenism;
  • TIPS (transjugular intrahepatic portosystemic shunt) for refractory variceal bleeding or ascites, at the cost of more encephalopathy;
  • surgical shunts are now rare;
  • liver transplantation is the definitive treatment.
• Liver abscess:

• Benign liver lesions:
  • hemangioma, the most common, with peripheral nodular enhancement and no need for biopsy;
  • focal nodular hyperplasia (central scar);
  • hepatic adenoma, linked to oral contraceptives, which can bleed or become malignant; stop the pill and resect large lesions;
  • hydatid cyst (echinococcosis): avoid spillage, which can cause anaphylaxis.
• Hepatocellular carcinoma:
  • risk factors: chronic hepatitis B (HCC can develop without cirrhosis), hepatitis C, alcohol, fatty liver disease and aflatoxin;
  • surveillance: ultrasound with or without AFP every 6 months in cirrhosis and high-risk HBV carriers;
  • diagnosis: classic arterial enhancement with portal venous washout on contrast CT or MRI, often without biopsy;
  • treatment depends on tumor burden and liver function: resection (preserved function, no significant portal hypertension), ablation for small tumors, liver transplantation (within Milan criteria), TACE (transarterial chemoembolization) for intermediate disease, and systemic therapy (atezolizumab with bevacizumab, or sorafenib or lenvatinib) for advanced disease.
• Colorectal liver metastases can be resected for cure in selected patients.

Pancreas

• Acute pancreatitis:
  • causes: gallstones and alcohol (most), hypertriglyceridemia, hypercalcemia, post-ERCP, drugs, trauma, scorpion venom and mumps;
  • diagnosis: two of three criteria (typical pain, lipase or amylase at least 3 times normal, imaging); CT is reserved for diagnostic doubt or for complications after 72 hours;
  • severity (revised Atlanta): mild (no organ failure), moderately severe (transient organ failure under 48 hours or local complications) and severe (persistent organ failure over 48 hours);
  • management: goal-directed fluids (lactated Ringer's), analgesia, early oral or enteral feeding, and no prophylactic antibiotics;
  • ERCP within 24 hours only for cholangitis or persistent biliary obstruction;
  • cholecystectomy during the same admission after mild gallstone pancreatitis to prevent recurrence.
• Local complications of acute pancreatitis:
  • acute peripancreatic fluid collections;
  • pseudocysts (encapsulated, more than 4 weeks, no necrosis), drained endoscopically or surgically only if symptomatic or infected;
  • walled-off necrosis;
  • infected necrosis (gas on CT, sepsis), managed with antibiotics and the step-up approach: percutaneous or endoscopic drainage first, then minimally invasive necrosectomy if needed, ideally after 4 weeks;
  • pseudoaneurysm bleeding;
  • splenic vein thrombosis.
• Chronic pancreatitis:
  • usually from alcohol; idiopathic or tropical forms also occur;
  • chronic pain, steatorrhea (exocrine insufficiency) and diabetes (endocrine insufficiency), with calcifications on imaging;
  • treated with abstinence, analgesia, pancreatic enzyme replacement and insulin, and drainage operations (lateral pancreaticojejunostomy, Puestow) or resection for a dilated duct or refractory pain.
• Pancreatic adenocarcinoma:
  • risk factors are smoking, chronic pancreatitis, diabetes and family history;
  • head tumors cause painless jaundice, weight loss and a Courvoisier gallbladder; body and tail tumors present late with back pain;
  • migratory thrombophlebitis (Trousseau sign) may occur;
  • CA 19-9 is used for follow-up;
  • pancreatic-protocol CT assesses resectability;
  • resectable head tumors (only about 15% to 20%) are treated by pancreaticoduodenectomy (Whipple procedure) with chemotherapy (FOLFIRINOX, gemcitabine-based);
  • unresectable disease is palliated with biliary stenting, duodenal stenting or bypass, celiac plexus block for pain, and chemotherapy.
• Neuroendocrine tumors:
  • insulinoma: Whipple triad (hypoglycemic symptoms, low glucose, relief with glucose), high insulin and C-peptide; treated by enucleation;
  • gastrinoma (Zollinger-Ellison) in the "gastrinoma triangle", part of MEN 1;
  • VIPoma and glucagonoma (necrolytic migratory erythema).

Spleen

• Indications for splenectomy:
  • trauma with hemodynamic instability or failed non-operative management;
  • hematologic disease: ITP refractory to medical therapy, hereditary spherocytosis, some hemolytic anemias and thalassemia with hypersplenism;
  • splenic abscess, cysts and tumors;
  • hypersplenism with cytopenias;
  • splenic artery aneurysm.
• Splenic injury:
  • hemodynamically stable patients are managed non-operatively with CT grading, monitoring and angioembolization, especially in children;
  • unstable patients with a positive FAST need laparotomy (splenorrhaphy or splenectomy).
• After splenectomy:
  • thrombocytosis (VTE risk);
  • Howell-Jolly bodies and target cells;
  • risk of overwhelming post-splenectomy infection (OPSI) from encapsulated bacteria (S. pneumoniae, Hib, N. meningitidis), with fulminant sepsis and DIC and high mortality, highest in children and in the first years.
• Preventing OPSI:
  • pneumococcal, Hib and meningococcal vaccines at least 2 weeks before elective splenectomy, or about 2 weeks after emergency splenectomy;
  • yearly influenza vaccine;
  • patient education and early antibiotics for fever (standby amoxicillin);
  • antibiotic prophylaxis in children.