Dynamics of tissue shrinkage during ablative temperature exposures

Area of Science:

• Biomedical Engineering
• Tissue Mechanics
• Thermal Therapy

Background:

• Thermal ablation techniques (radiofrequency, microwave, ultrasound) use heat to treat diseases.
• Heat-induced tissue shrinkage, caused by protein denaturation and dehydration, impacts image-guided procedures.
• Accurate assessment of treatment outcomes requires accounting for dimensional changes in organs.

Purpose of the Study:

• To investigate the dynamics of heat-induced shrinkage in organ tissues.
• To develop a mathematical model for predicting tissue shrinkage based on time and temperature.
• To quantify shrinkage in porcine liver tissue under various thermal conditions.

Main Methods:

• Ex vivo isothermal shrinkage tests were performed on porcine liver tissue.
• Axial length changes were recorded during 15-minute heating intervals at temperatures from 60°C to 95°C.
• A mathematical model was developed to describe shrinkage behavior.

Main Results:

• Tissue shrinkage dynamics were consistent across tested temperatures.
• Estimated relative shrinkage after 15 minutes increased with temperature: 12.3% (60°C) to 21.7% (95°C).
• Shrinkage was adjusted for time since death to ensure data accuracy.

Conclusions:

• Organ tissue shrinkage is a significant phenomenon during thermal treatments.
• The developed mathematical model accurately describes time- and temperature-dependent shrinkage.
• Considering tissue shrinkage is essential for precise image-guided thermal ablative therapies.