What is the anatomy of the hepatobiliary system according to Bailey and Love's (Bailey and Love) textbook of surgery?

Anatomy of the Hepatobiliary System According to Bailey and Love's Textbook of Surgery

The hepatobiliary system has significant anatomical variability with variant rates exceeding 40% among individuals, making a thorough understanding of its anatomy essential for safe surgical interventions and prevention of bile duct injuries.

Liver Anatomy and Biliary Tree Structure

• The liver is divided into functional segments based on vascular supply and biliary drainage, with the hepatocystic triangle (composed of the cystic duct, common bile duct, and liver) being a crucial anatomical landmark during cholecystectomy 1
• The biliary tree consists of intrahepatic and extrahepatic components with high anatomical variability that must be recognized during surgical procedures 2, 3
• The extrahepatic biliary system includes the common hepatic duct, cystic duct, common bile duct, and their junction points, with the choledochoduodenal junction forming an important sphincter mechanism 4

Critical Anatomical Landmarks for Surgery

• The Critical View of Safety (CVS) technique requires identification of the hepatocystic triangle, clearance of the lower third of the gallbladder from the liver bed, and visualization of only two structures (cystic duct and artery) entering the gallbladder 1
• Complete CVS is achievable in only about 50% of cases, with the most commonly incomplete component being clearance of the lower third of the gallbladder from the liver bed 1
• When CVS cannot be achieved due to inflammation or fibrosis, alternative approaches such as the "fundus-first" technique or subtotal cholecystectomy should be considered to prevent bile duct injuries 1

Hilar Anatomy and Surgical Approaches

• The hilar plate forms an important anatomical landmark that can be approached through several techniques during complex biliary surgery 1
• Surgical approaches to the hepatic hilum include: approach through the hilar plate, approach through the upper portion of hepatic portal, approach through fissure of umbilical vein, and approach through posterior portion of hepatic portal 1
• For high-level bile duct injuries, following the principle of "bile duct is three rather than two" helps avoid missing the right posterior hepatic duct during repair procedures 1

Vascular Anatomy Related to Biliary System

• The hepatic artery and portal vein run alongside the biliary tree in the hepatoduodenal ligament, with variations in this vascular anatomy occurring in approximately 40% of individuals 3, 4
• During cholecystectomy, the cystic artery must be carefully identified as it typically runs parallel to the cystic duct but has numerous anatomical variations 1
• In mice (often used as experimental models), the arteria gastrica sinistra accessoria is commonly found among biliary arteries, which rarely appears in humans 5

Lymphatic Drainage and Surgical Implications

• Regional lymphadenectomy is recommended during liver resection for cholangiocarcinoma, with recovery of at least six lymph nodes recommended for complete nodal staging 1
• Adequate lymphadenectomy provides better survival outcomes for patients with node-positive disease on pathology, supporting its routine use in hepatobiliary surgery 1

Anatomical Variations and Classification Systems

• Multiple classification systems exist for biliary anatomy variations, including those by Couinaud, Huang, Karakas, Choi, Champetier, and Ohkubo, with the Ohkubo system being the most clinically applicable 6
• Normal biliary anatomy is present in only about 57.8% of individuals, with the remainder having significant variations that must be recognized during surgery 6
• Magnetic resonance cholangiopancreatography (MRCP) represents the "gold standard" for complete morphological evaluation of biliary tree anatomy, with excellent correlation to direct cholangiography 1, 6

Surgical Considerations Based on Anatomy

• For anastomotic bile duct repair, healthy, non-ischemic, non-inflamed tissue must be used, with appropriate pruning or plastic surgery to prepare the proximal and distal bile ducts 1
• Fine suture techniques (5-0 or 6-0) should be used for biliary anastomosis, with single-layer stitching, uniform margins, and appropriate tension to prevent leakage while preserving blood supply 1
• In cases of bile duct injury, the approach to repair depends on the level and extent of injury, with higher injuries requiring more complex reconstruction techniques 1