What are spiral valves in a cholecystectomy (surgical removal of the gallbladder)?

Spiral Valves in Cholecystectomy

Spiral valves, also known as Heister valves, are mucosal folds located on the endoluminal surface of the cystic duct that can impact surgical technique during cholecystectomy and may contribute to bile duct injury if not properly identified.

Anatomy and Characteristics of Spiral Valves

• Spiral valves (Heister valves) were first described by Lorenz Heister in 1732 and are mucosal folds on the inner surface of the cystic duct 1
• These valves create a mulberry-like, pleated surface structure similar to the epithelial lining of the gallbladder 2
• Contrary to their name, these valves don't always form a true spiral pattern:
  • In over half of cases, spiraling is not the dominant feature 3
  • The valves can have various configurations including oblique, uniform, and non-reticular patterns 1
  • The term "valve" is somewhat misleading as they regulate bile flow in both directions rather than acting as true one-way valves 3

Clinical Significance During Cholecystectomy

• Heister valves can represent an obstacle during transcystic exploration and may complicate surgical procedures 1
• The presence of these valves affects bile flow mechanics between the gallbladder and common bile duct, which has implications for:
  • Allowing low-viscosity hepatic bile to enter the gallbladder under low pressure
  • Facilitating expulsion of more viscous gallbladder bile 3

Relationship to Cystic Duct Variations and Bile Duct Injury

• Cystic duct variations associated with spiral valves can increase the risk of bile duct injury during cholecystectomy 4
• Clinically important variations related to spiral valves include:
  • Spiral courses of the cystic duct (anterior and posterior)
  • Parallel courses along the common bile duct
  • Low insertions of the cystic duct
  • Right hepatic duct drainage 4
• These variations are present in approximately 11.7% of patients undergoing cholecystectomy 4

Surgical Considerations

• When performing cholecystectomy, surgeons must be aware of the potential for spiral valve-related anatomical variations 5
• The Critical View of Safety (CVS) technique is essential to minimize the risk of bile duct injury related to cystic duct variations 5, 6
• Key considerations include:
  • Spiral courses may have two patterns: anterior and posterior, with anterior ones typically found in high insertion cases 4
  • Posterior insertions frequently exist in low insertions (75%) and never in high insertions 4
  • Anterior insertions coexist with high insertions and never with low insertions 4

Prevention of Bile Duct Injury Related to Spiral Valves

• Proper identification of biliary anatomy, particularly when spiral valves create unusual cystic duct configurations, is crucial 5, 6
• When the Critical View of Safety cannot be achieved due to anatomical variations:
  • Consider bailout procedures such as the "fundus-first" approach or subtotal cholecystectomy 5
  • Use intraoperative imaging techniques like cholangiography (IOC) or indocyanine green fluorescence cholangiography (ICG-C) to better visualize the biliary anatomy 5, 6
• Be particularly cautious of parallel and spiral anomalies of the cystic duct, which are found in approximately every fourth or fifth patient 7

Potential Complications

• Leaving a hidden long stump of an anomalous cystic duct with spiral valves can result in post-cholecystectomy complications 7
• The length of anomalous courses of the cystic duct can vary significantly:
  • 20-25 mm in some patients
  • 30-50 mm in most cases
  • Up to 60-75 mm in others 7

Understanding the variable anatomy of spiral valves and associated cystic duct variations is essential for surgeons performing cholecystectomy to minimize the risk of bile duct injury and ensure optimal surgical outcomes.