Hepatocystic triangle

The hepatocystic triangle, also known as hepatobiliary triangle or Calot triangle, is a small triangular space at the porta hepatis of surgical importance as it is dissected during cholecystectomy. Its contents, the cystic artery and cystic duct, must be identified before ligation and division to avoid intraoperative injury.

Gross anatomy

Boundaries

In the generally accepted definition, the triangle has the following boundaries:

• inferior: cystic duct, which is often tortuous and has a beaded appearance, passes downward and to the left from the neck of the gallbladder to join the common duct

• left: common hepatic duct

• superior: inferior surface of the liver

Contents

• right hepatic artery

• cystic artery

• cystic lymph node (of Lund)

• connective tissue

• lymphatics

• occasionally accessory hepatic ducts and arteries

Variant anatomy

• cystic artery and right hepatic artery exhibit a wide spectrum of anatomical variation, as a consequence they are sometimes absent from the hepatocystic triangle ^4-6

Clinical importance

• as numerous variations in the number of cystic arteries and its origin exist, it is important that surgeons performing cholecystectomies, as well as radiologists imaging this area, have a good understanding of the anatomy of the triangle and the common anatomical variations therein ^4-6

History and etymology

This space was first described by the French surgeon, Jean-François Calot (1861–1944) ² in 1891, as part of his PhD thesis. The triangle as described by Calot differs slightly from the modern description in that he described the superior border as the cystic artery rather than the surface of the liver ³.