What is Calot's triangle?

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Last updated: May 11, 2025View editorial policy

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From the Guidelines

Calot's triangle is a critical anatomical landmark in gallbladder surgery, bounded by the cystic duct, common hepatic duct, and inferior border of the liver, containing the cystic artery and lymph node. The identification and dissection of this triangle is crucial to prevent complications such as bile duct injury or hemorrhage during cholecystectomy, as emphasized in the 2020 World Society of Emergency Surgery guidelines for the diagnosis and treatment of acute calculus cholecystitis 1. The triangle's boundaries and contents are essential for surgeons to understand, as they must carefully dissect this area to achieve the "critical view of safety" and prevent inadvertent injury to the common bile duct. Key considerations in this context include:

  • The cystic duct on the right side
  • The common hepatic duct on the left side
  • The inferior border of the liver at the top
  • The cystic artery and lymph node within the triangle
  • The potential for accessory hepatic ducts Surgeons must be aware of the importance of proper identification and dissection of Calot's triangle, as highlighted in the guidelines, to minimize the risk of complications and ensure a safe and successful surgical outcome, particularly in cases where conversion from laparoscopic to open cholecystectomy is considered due to severe local inflammation, adhesions, bleeding from the Calot’s triangle, or suspected bile duct injury 1.

From the Research

Definition of Calot's Triangle

  • Calot's triangle is an anatomical landmark of special value in cholecystectomy, first described by Jean-François Calot in 1891 2.
  • It is defined as an anatomical space that requires careful dissection before the ligation and division of the cystic artery and cystic duct during cholecystectomy.

Boundaries and Variations

  • The modern definition of the boundaries of Calot's triangle varies from Calot's original description, although the exact timing of this change is not entirely clear 2.
  • The structures within Calot's triangle and their anatomical relationships can present the surgeon with difficulties, particularly when anatomical variations are encountered 2.
  • Variations in cystic arterial supply can be observed, with a typical arterial supply found in 76.6% of cases, and atypical arterial supply found in 23.4% of cases 3.

Clinical Significance

  • Sound knowledge of the normal anatomy of the extrahepatic biliary tract and vasculature, as well as understanding of congenital variation, is essential in the prevention of iatrogenic injury 2.
  • Careful dissection of Calot's triangle and the hepatoduodenal ligament can help avoid accidents involving vessels or the common bile duct during laparoscopic cholecystectomy 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Calot's triangle.

Clinical anatomy (New York, N.Y.), 2013

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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