Assessment of the thermal outcome during steam-pulse ablation for sheep tissue. (1st October 2021)

• Record Type: Journal Article
• Authors: Anzai, Hitomi; Stämpfli, Rolf; Wang-Leandro, Adriano; Boesel, Luciano F.; Kemp, Shelley; Rossi, Rene M.; Karol, Agnieszka A.; Ohta, Makoto; Richter, Henning
• Is Part Of: Thermal science and engineering progress. Volume 25(2021)
• Publication Date: 2021-10-01
• Subjects: Steam ablation -- Thermal propagation -- Ex vivo test -- Computational simulation; Heat engineering -- Periodicals; Heat engineering; Thermodynamics; Periodicals; 621.402
• DOI: 10.1016/j.tsep.2021.100966
• Languages: English
• ISSNs: 2451-9049

Abstract

Highlights: Ex vivo test was performed using sheep tissues and to assess steam flow ablation. Ex vivo measurements shows heating effect is limited, and defect range was <1 cm. Numerical simulation shows heated area near to catheter tip and along biopsy needle. Clear boundary between normal and defect area with coagulative necrosis is observed. Abstract: Thermal ablation has attracted attention as a minimally invasive tissue ablation treatment. Steam flow was recently introduced as a novel ablation procedure. This work aimed to assess the applicability of pulsated steam flow for tumor ablation. Ex vivo ablation was performed using liver, muscle, and fat tissues of sheep. Three experimental protocols of pulse number were administered to these tissues, while computational simulation was conducted according to the ex vivo tests for each tissue. Real-time measurements of temperature revealed heat propagation during and subsequent to ablation. The peak temperature was achieved after ablation. The time to reach the peak (highest temperature) increased with the distance from the thermal sensor to the steam needle according to thermal conductivity, except for steam leakage along to gap between the tissue and blood vessel. A cross-section of the ablated specimen clearly revealed the boundaries of cell defects. The ablated area was droplet shaped up to the steam needle. Computational simulations revealed that the ablated area was consistent with the area with the highest temperature. Though several limitations still remain such as no blood circulation, pulsated steam flow can ablate diverse animal tissues.