A mechanical model for CCK-induced acalculous gallbladder pain

Area of Science:

• Gastroenterology
• Biomedical Engineering
• Medical Physics

Background:

• Acalculous biliary pain is a clinical challenge.
• Previous models estimated gallbladder stress but overlooked active stress components.
• Cholecystokinin (CCK) tests induce gallbladder contraction and pain.

Purpose of the Study:

• To investigate the correlation between mechanical stress and acalculous biliary pain.
• To develop a model that incorporates both active and passive stress components in the gallbladder.
• To evaluate the predictive capability of this model for CCK-induced pain.

Main Methods:

• Utilized a mathematical model of the gallbladder as a thin ellipsoidal membrane.
• Estimated active and passive stress components from in vivo ultrasonographical measurements during CCK tests.
• Applied the model to 51 subjects, correlating peak stress with patient pain scores.

Main Results:

• Peak total stress in the gallbladder showed a strong correlation with CCK-induced pain.
• The model successfully predicted CCK-induced pain in over 75% of subjects.
• The contribution of gallbladder-to-liver stress was found to be minimal.

Conclusions:

• Mechanical stress, particularly active stress during contraction, is a key factor in acalculous biliary pain.
• The developed model offers a promising tool for predicting CCK-induced pain.
• This approach enhances understanding of gallbladder physiology and pain mechanisms.