Effects of saline volume on lesion formation during saline-infused radiofrequency ablation

- A numerical model to predict lesion size following saline infused RFA is developed.
- The model solves for saline transport, tissue joule heating and tissue death.
- Optimum saline infusion prior to RFA increases the lesion size by 89%.
- Increasing the infusion volume did not always lead to larger lesions.
- There is an optimum volume that produces the largest increase in lesion size.

Radiofrequency ablation (RFA) is hindered when tissue temperature reaches 100 °C. At this temperature, tissue vaporization occurs, which prevents electrical currents from flowing into the tissue. Smaller lesions are created as a result. One way to overcome this is to infuse saline into the tissue prior to RFA. Saline can increase the electrical conductivity of the surrounding tissue due to the abundance of ions inside the solution. This permits a greater distribution of electrical currents that can lead to larger lesion sizes. Although this procedure has been shown to produce larger lesions, the technique is risky due to the potential for the saline to extravasate into healthy regions of the tissue; hence, leading to unnecessary ablation. A computational model is developed in this paper to predict the formation of lesion following saline-infused RFA. The model incorporates the transport of saline inside the tissue, the resistive heating during ablation and the formation of lesion through cell death modeling. Results show that there is an optimal infusion volume that leads to the largest increase in the lesion size. With further developments, the model may be used for the planning of saline-infused RFA treatment.