Radiofrequency Tissue Ablation: Effect of Hepatic Blood Flow Occlusion on Thermal Injuries Produced in Cirrhotic Livers

Abstract

Ablation area is increased significantly with hepatic blood flow occlusion in the human cirrhotic liver. This result may have application in the treatment of larger (>3 cm) hepatic malignancies.

Impact of Blood Flow Occlusion on Liver Necrosis Following Thermal Ablation

“…Similar increases ranging from two‐ to six‐fold have been demonstrated with various other techniques of thermal ablation, namely radiofrequency ablation and microwave coagulation 3,7–9 . A number of clinical studies report increased ablation volumes with hepatic blood flow occlusion at open or laparoscopic surgery 6,19,25–28 . These studies generally describe imaging results without providing direct histological evidence of significant increases in the volume of necrosis with blood flow occlusion.…”

Effect of Change in Portal Venous Blood Flow Rates on the Performance of a 2.45-GHz Microwave Ablation Device

“…The consensus from those experiments is that blood vessels larger than 3-4 mm adjacent to or embedded within ablation zones cause substantial local "heat sink effect" on radiofrequency ablation zones but little to no effect on microwave ablation zones created by using either 915-MHz or 2.45-GHz devices (14)(15)(16)(17)(18)(19)(20)(21). Also, temporary occlusion of regional or global hepatic blood flow causes an increase in the overall size of ablation zones created by radiofrequency and microwave ablation devices (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)13,17,22,23). The studies of the change in hepatic blood flow within the normal physiological range have demonstrated as much as a threefold decrease in radiofrequency ablation zone volume as hepatic blood flow reaches upper physiological rates (11,25) but little to no effect of physiological fluctuations in hepatic blood flow on ablation zone volume created by 915-MHz microwave ablation devices (25).…”

Feasibility of bloodless liver resection using Lumagel, a reverse thermoplastic polymer, to produce temporary, targeted hepatic blood flow interruption

“…Facilitating hepatic resection by blood flow interruption becomes of significance in facilitating minimally invasive or robotic techniques. However, blood flow interruption in the liver may have wider implications in the fields of ablative therapies for liver masses and for chemotherapy and gene therapy 12,13 . Blood flow interruption to enhance ablative therapies for liver tumours has been advocated but hindered by the absence of a safe and simple means of providing it 14 .…”