PURPOSE: To determine whether vasoactive pharmacologic agents can alter radio-frequency (RF)-induced coagulation necrosis by modulating hepatic blood flow. MATERIALS AND METHODS: RF ablation was performed in normal, in vivo porcine liver with 1.5-cm internally cooled electrodes and a standardized RF application (i.e., 500 mA for 10 minutes). Ablation was performed without (n = 9) and with pharmacologic modulation of blood flow with halothane (n = 7), vasopressin (n = 6), or epinephrine (n = 7). Laser Doppler techniques were used to quantify changes in hepatic blood flow. Remote thermometry was also performed. Blood flow was correlated with both induced coagulation necrosis and tissue temperatures. RESULTS: Halothane reduced mean blood flow (+/- SD) to 46.1% +/- 8.5 of normal, and vasopressin increased mean blood flow to 132.7% +/- 13.9. Epinephrine caused increased hepatic blood flow centrally (171.1% +/- 31.7) but not peripherally (102.8% +/- 15.4). Mean coagulation diameter was 1.4 cm +/- 0.3 with vasopressin, 2.2 cm +/- 0.4 with normal blood flow, and 3.2 cm +/- 0.1 with halothane (P < .01). After epinephrine infusion, mean coagulation measured 2.3 cm +/- 0.3 peripherally and 1.4 cm +/- 0.5 centrally (P < .01). A linear correlation between coagulation diameter and blood flow was demonstrated (r2 = 0.78). Temperatures 10 and 15 mm from the electrode correlated with both blood flow and coagulation diameter (r2 = 0.65 and 0.60, respectively). CONCLUSION: The coagulation necrosis achieved for a standardized RF application correlates with relative tissue perfusion. Pharmacologic reduction of blood flow during thermally mediated percutaneous ablation may induce greater coagulation necrosis.
PURPOSE: To determine whether vasoactive pharmacologic agents can alter radio-frequency (RF)-induced coagulation necrosis by modulating hepatic blood flow. MATERIALS AND METHODS: RF ablation was performed in normal, in vivo porcine liver with 1.5-cm internally cooled electrodes and a standardized RF application (i.e., 500 mA for 10 minutes). Ablation was performed without (n = 9) and with pharmacologic modulation of blood flow with halothane (n = 7), vasopressin (n = 6), or epinephrine (n = 7). Laser Doppler techniques were used to quantify changes in hepatic blood flow. Remote thermometry was also performed. Blood flow was correlated with both induced coagulation necrosis and tissue temperatures. RESULTS:Halothane reduced mean blood flow (+/- SD) to 46.1% +/- 8.5 of normal, and vasopressin increased mean blood flow to 132.7% +/- 13.9. Epinephrine caused increased hepatic blood flow centrally (171.1% +/- 31.7) but not peripherally (102.8% +/- 15.4). Mean coagulation diameter was 1.4 cm +/- 0.3 with vasopressin, 2.2 cm +/- 0.4 with normal blood flow, and 3.2 cm +/- 0.1 with halothane (P < .01). After epinephrine infusion, mean coagulation measured 2.3 cm +/- 0.3 peripherally and 1.4 cm +/- 0.5 centrally (P < .01). A linear correlation between coagulation diameter and blood flow was demonstrated (r2 = 0.78). Temperatures 10 and 15 mm from the electrode correlated with both blood flow and coagulation diameter (r2 = 0.65 and 0.60, respectively). CONCLUSION: The coagulation necrosis achieved for a standardized RF application correlates with relative tissue perfusion. Pharmacologic reduction of blood flow during thermally mediated percutaneous ablation may induce greater coagulation necrosis.
Authors: Daniel A Finelli; Ali R Rezai; Paul M Ruggieri; Jean A Tkach; John A Nyenhuis; Greg Hrdlicka; Ashwini Sharan; Jorge Gonzalez-Martinez; Paul H Stypulkowski; Frank G Shellock Journal: AJNR Am J Neuroradiol Date: 2002 Nov-Dec Impact factor: 3.825
Authors: Alban L Denys; Thierry De Baere; Viseth Kuoch; Benoit Dupas; Patrick Chevallier; David C Madoff; Pierre Schnyder; Francesco Doenz Journal: Eur Radiol Date: 2003-08-27 Impact factor: 5.315
Authors: Jeong Min Lee; Young Kon Kim; Sang Won Kim; Joon Koo Han; Se Hyung Kim; Byung Ihn Choi Journal: Korean J Radiol Date: 2004 Jan-Mar Impact factor: 3.500