Radiology: Irreversible electroporation a viable tissue removal technique
In an animal model, irreversible electroporation (IRE) was found to be a fast, safe and potent ablative method, causing complete tissue death by means of apoptosis, according to a study published in the May edition of Radiology.
In evaluating the effectiveness of IRE in hepatic tissue ablation and the radiologic-pathologic correlation of IRE-induced cell death, Edward W. Lee, MD, PhD, from the division of interventional radiology at the Ronald Reagan Medical Center of the University of California, Los Angeles, David Geffen School of Medicine in Los Angeles, and colleagues found that cell death was seen with full preservation of periablative zone structures, including blood vessels, bile ducts and neighboring nonablated tissues by way of IRE. In addition, ultrasound was able to monitor the therapeutic response.
“With the high demand for alternative treatments for primary, as well as metastatic, hepatic malignancies, many newer focal ablative methods that complement conventional oncologic therapies have been developed and investigated,” said the authors. “Some have shown promising results and the potential to be an effective alternative option for patients.”
The researchers utilized 16 female Yorkshire pigs with a weight range of 30 kg-60 kg following approval of the Animal Care and Use Committees of University of California Regents for their study.
Each animal underwent ultrasonography-guided IRE of normal liver. According to the authors, a total of 55 ablation zones were created, which were monitored with and measured in real time with ultrasound both immediately after the procedure and again 24 hours after the procedure. The ablation zones were also imaged with MRI and CT and evaluated through immunohistochemical analysis for complications, including bleeding, infection, biliary complications, adjacent organ damage, liver failure and cardiac complications.
The average diameter of the ablation zones was 33.5 mm and had an average total procedure time of 6.9 minutes per ablation, with a standard difference of 2.5 mm between ultrasound and gross section measurements.
The authors wrote, “IRE ablation zones were well characterized with ultrasound, CT and MR imaging and real-time monitoring was feasible with ultrasound.” Complete cell death was noted with a well-defined treatment area and bile ducts and vessels remained completely preserved. Areas of complete cell death were stained positive for apoptotic markers, which according to the researchers, suggested the involvement of the apoptotic process in the pathophysiology of cell death caused by IRE.
Moreover, the researchers did not observe complications in any of the animals involved in the research.
In terms of the implications of the method for human patients, Lee and colleagues said that IRE can potentially be used as a tumor ablation technique for hepatic tumors. “IRE demonstrates a complete ablation zone up to the vessel walls, demonstrating that, in clinical practice, IRE may be less affected by the heat sink effect than are presently available modalities,” they concluded.
In evaluating the effectiveness of IRE in hepatic tissue ablation and the radiologic-pathologic correlation of IRE-induced cell death, Edward W. Lee, MD, PhD, from the division of interventional radiology at the Ronald Reagan Medical Center of the University of California, Los Angeles, David Geffen School of Medicine in Los Angeles, and colleagues found that cell death was seen with full preservation of periablative zone structures, including blood vessels, bile ducts and neighboring nonablated tissues by way of IRE. In addition, ultrasound was able to monitor the therapeutic response.
“With the high demand for alternative treatments for primary, as well as metastatic, hepatic malignancies, many newer focal ablative methods that complement conventional oncologic therapies have been developed and investigated,” said the authors. “Some have shown promising results and the potential to be an effective alternative option for patients.”
The researchers utilized 16 female Yorkshire pigs with a weight range of 30 kg-60 kg following approval of the Animal Care and Use Committees of University of California Regents for their study.
Each animal underwent ultrasonography-guided IRE of normal liver. According to the authors, a total of 55 ablation zones were created, which were monitored with and measured in real time with ultrasound both immediately after the procedure and again 24 hours after the procedure. The ablation zones were also imaged with MRI and CT and evaluated through immunohistochemical analysis for complications, including bleeding, infection, biliary complications, adjacent organ damage, liver failure and cardiac complications.
The average diameter of the ablation zones was 33.5 mm and had an average total procedure time of 6.9 minutes per ablation, with a standard difference of 2.5 mm between ultrasound and gross section measurements.
The authors wrote, “IRE ablation zones were well characterized with ultrasound, CT and MR imaging and real-time monitoring was feasible with ultrasound.” Complete cell death was noted with a well-defined treatment area and bile ducts and vessels remained completely preserved. Areas of complete cell death were stained positive for apoptotic markers, which according to the researchers, suggested the involvement of the apoptotic process in the pathophysiology of cell death caused by IRE.
Moreover, the researchers did not observe complications in any of the animals involved in the research.
In terms of the implications of the method for human patients, Lee and colleagues said that IRE can potentially be used as a tumor ablation technique for hepatic tumors. “IRE demonstrates a complete ablation zone up to the vessel walls, demonstrating that, in clinical practice, IRE may be less affected by the heat sink effect than are presently available modalities,” they concluded.