p` MM @@@ @@@@O =QLpM0 EN DB M@P     & . 67FTdjAdultowaves/tu [Therapeutic Use]erapy]CYSZ ! CYY 8X58BAgedtowaves/tu [Therapeutic Use]erapy]CYSZ ! CYY 8X58BpB nnn{\rtf1\ansi{\fonttbl}{\colortbl\red0\green0\blue0;\red255\green0\blue0;\red0\green0\blue255;}{8v Accocella1999Andersson-Engels1997 Aschoff2001 Athanasoulis1998 Bessoud2002 Boige2002 Chinn2001 Chinn2001 Compton1998 De1999a de Baere2002 Dromain2002 Ducreux2002 Duerk2001 Elias2002 Fogle1998 Garbagnati1999 Gazelle1998 Gazelle1998 Girish20022Goldberg1998Goldberg1998 Hahn19981 Hahn19981 Halpern1998 Heisterkamp1999 Ijzermans1999 Johnson2001 Kennedy2001 Lassau20022 Lee2001Lencioni19999Leonardi19999 Lewin2001 Liu1997 Mahvi2001 Mendez20011 Merkle20011 Mueller1998 Paties19999Quaretti19999 Roche2002 Rossi1999 Schima19988 Smayra20022Solbiati19981 Stenram1997 Sturesson1997 Tanabe19989van Hillegersberg1999 Warner20011 Winter20011 Wong20010 Zangrandi1999 Zhang2001 Zondervan1999 Zondervan1999 Zondervan1999 Zondervan1999 Zondervan1999 Zondervan199901 Zondervan1999 Zondervan1999   AuthorsDJournals Keywords                                 hD Accocella, F.Andersson-Engels, S. Aschoff, A.J.Athanasoulis, C.A. Bessoud, B. Boige, V. Burgoa, L. Chinn, C. Chinn, S.B.Christians, K. K. Compton, C.C. Coppa, J. de Baere, T.De, Francesco, I Dromain, C. Ducreux, M. Duerk, J.L. Elias, D. Fabbri, A. Fogle, R.M. Foley, W. D.Garbagnati, F. Gazelle, G.S. Girish, B. V.Goldberg, S.N. Hahn, P.F. Halpern, E.F.Heisterkamp, J.Ijzermans, J.N.M. Johnson, C.D. Kennedy, G.D. Lassau, N.Lee, F.T., Jr. Lencioni, R. Leonardi, L. Lewin, J.S. Liu, D.L. Mahvi, D.M. Marchiano, A.Mazzaferro, V. Mendez, M.M. Merkle, E.M. Mueller, P.R. Paties, C. Pitt, H. A.Pulvirenti, A. Quaretti, P.Quebbeman, E. J. Quiroz, F. A. Regalia, E. Roche, A. Romito, R. Rossi, S. Schiavo, M. Schima, W. Smayra, T. Solbiati, L. Stenram, U. Sturesson, C. Tanabe, K.K.van Hillegersberg, R.Wallace, J. R. Warner, T.F.Winter, T.C., III Wong, V. Zangrandi, A. Zhang, Q.Zondervan, P.E.  d ,&AJR. American Journal of Roentgenology(%AJR.American Journal of Roentgenology(#Journal of Gastrointestinal Surgery(%Journal of Magnetic Resonance Imaging Journal of Surgical Research4.Journal of Vascular & Interventional Radiology40Journal of Vascular and Interventional Radiology Radiology Transplantation Proceedings Tumori  *Balloon Occlusion*Blood Coagulation,'*Carcinoma, Hepatocellular/su [Surgery],'*Carcinoma, Hepatocellular/th [Therapy]*Catheter Ablation$*Catheter Ablation/mt [Methods]($*Colorectal Neoplasms/pa [Pathology]*Electrocoagulation*Heat*Hepatic Arteryio*Hepatic Veins*Hyperthermia, Induced("*Hyperthermia,Induced/mt [Methods]*Hypothermia,Induced*Liver Circulation($*Liver Circulation/de [Drug Effects]$!*Liver Neoplasms/ra [Radiography]$*Liver Neoplasms/sc [Secondary] *Liver Neoplasms/su [Surgery] *Liver Neoplasms/th [Therapy]*Liver Transplantation*Liver/bs [Blood Supply]*Liver/pa [Pathology]*Liver/su [Surgery]es *Magnetic Resonance Imaging0**Magnetic Resonance Imaging/st [Standards]$*Neoplasm Staging/mt [Methods] *Portal Veinu$*Preoperative Care/mt [Methods]0**Tomography, X-Ray Computed/st [Standards] 0 (Anesthetics,Inhalation)0 (Contrast Media)e I 0 (Vasoconstrictor Agents)0 (Vasopressins)151-67-7 (Halothane)51-43-4 (Epinephrine) 80529-93-7 (Gadolinium DTPA)AdultAged analysisu,(Anesthetics,Inhalation/pd [Pharmacology] Animal93-Balloon DilatationBalloon OcclusionBias (Epidemiology)blood blood supply0+Carcinoma, Hepatocellular/bs [Blood Supply],(Carcinoma, Hepatocellular/di [Diagnosis]Catheter Ablation Cattle,&Colorectal Neoplasms/bs [Blood Supply](#Colorectal Neoplasms/di [Diagnosis](#Colorectal Neoplasms/pa [Pathology](#Colorectal Neoplasms/sc [Secondary]$!Colorectal Neoplasms/th [Therapy]COLORECTAL-CANCERComparative Study ConstrictionSConstriction,PathologicContrast Mediadol Cryosurgery$Electrocoagulation/mt [Methods] Electrodes Epinephrine/pd [Pharmacology]Feasibility Studies FemaleictFIBERFollow-Up Studies(#Gadolinium DTPA/du [Diagnostic Use] Halothane/pd [Pharmacology]HeatHepatic ArteryS.G$ Hepatic Artery/de [Drug Effects](#Hepatic Artery/pp [Physiopathology] Hepatic Artery/su [Surgery]tiHEPATIC METASTASES Hepatic VeinsHumanINDUCED THERMOTHERAPYLaser Coagulation LigationALiver Liver Cirrhosis/su [Surgery]Liver Neoplasms$!Liver Neoplasms/bs [Blood Supply]$Liver Neoplasms/di [Diagnosis]$Liver Neoplasms/sc [Secondary] Liver Neoplasms/su [Surgery]Liver/pa [Pathology]sLiver/su [Surgery][Su Magnetic Resonance Imaging]tiMale methodsa  Middle AgeMODEL,)Monitoring, Intraoperative/st [Standards] Morbidity mortalityMRI Necrosis $Neoplasm Staging/st [Standards] PerfusionPHOTOCOAGULATION Portal Veiner Portal Vein/de [Drug Effects]$ Portal Vein/pp [Physiopathology]Portal Vein/su [Surgery]n$ Preoperative Care/st [Standards] RabbitsVeRandom AllocationRatsRats,Inbred WF Sensitivity and SpecificitySingle-Blind MethodSupport, Non-U.S. Gov'tSupport,Non-U.S.Gov'tSwine Temperatureertherapeutic blockade therapy Time FactorstTIPTreatment Outcome TUMORS$Ultrasonography/st [Standards] United States,(Vasoconstrictor Agents/pd [Pharmacology]$Vasopressins/pd [Pharmacology]  24How does alteration of hepatic blood flow affect liver perfusion and radiofrequency-induced thermal lesion size in rabbit liver?RKAschoff,A.J. Merkle,E.M. Wong,V. Zhang,Q. Mendez,M.M. Duerk,J.L. Lewin,J.S. 2001 1/2001*Catheter Ablation *Liver Circulation *Liver/pa [Pathology] *Magnetic Resonance Imaging 0 (Contrast Media) 80529-93-7 (Gadolinium DTPA) Animal Contrast Media Gadolinium DTPA/du [Diagnostic Use] Hepatic Artery/su [Surgery] Ligation Liver Liver/su [Surgery] Magnetic Resonance Imaging Necrosis Portal Vein/su [Surgery] Rabbits Random Allocation Support,Non-U.S.Gov't United States blood Perfusion Hepatic Artery Portal Vein Temperature analysis 57-63e,%Journal of Magnetic Resonance Imaging 131r l fThe purpose of this study was to test the hypothesis that decreasing liver perfusion in rabbits results in an increase in thermal lesion size and that these effects can be accurately monitored using magnetic resonance imaging (MRI). We additionally tested the hypothesis that the increase in thermal lesion size would depend on the particular vessel or vessels occluded (hepatic artery, portal vein, or both). Using an Institutional Animal Care and Use Committee approved protocol, 20 New Zealand white rabbits were randomly assigned to four treatment groups (five in each group): control and ligation of portal vein (PV), hepatic artery (HA), or both PV and HA (HAPV). Surgical ligation of the appropriate vessel was performed under general anesthesia. Immediately after ligation, the rabbits were placed in a 0.2-T open MR system, and an 18-G copper radiofrequency (RF) electrode with a 2-cm exposed tip was inserted into the liver. RF was applied for 10 minutes with the tip temperature maintained at 90 degrees +/- 2 degrees C. Before and after ablation, perfusion data were obtained for 90 seconds using 30 3-second sequential single oblique-slice fast imaging with steady-state progression (FISP) acquisitions after injection of gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) via the inferior vena cava. Postablation scanning included axial and oblique turbo spin-echo (TSE) T2-weighted (T2w), STIR, and Gd-enhanced T1w sequences. Lesion size was determined perpendicular to the RF electrode using software calipers on the imager. The rabbits were sacrificed after completion of the post-therapy scans, and their livers were harvested for histologic analysis. The liver showed a mean increase in signal amplitude (SA) of 76% 24 seconds after Gd contrast injection in the control group. After contrast injection, the SA increased to a mean of only 66% in the group with ligated hepatic arteries, with no difference in the time to peak compared with the control group. No significant SA increase over baseline could be found in the groups with ligated PV or ligated PV and HA. T2-weighted images demonstrated the highest lesion-to-liver contrast-to-noise ratios (CNRs; mean -5.5) on postprocedure images, followed by STIR images (mean -2.2) in the control group. The lesions were poorly delineated on the Gd-enhanced images. Average maximum lesion sizes (mean +/- 95% confidence interval) were 22 +/- 4.3 mm after ligation of PV, 22 +/- 2.6 mm after ligation of both PV and HA, 14 +/- 2.0 mm after ligation of HA, and 13 +/- 1.9 mm in the control group. We accept the hypothesis that the diameter of the region of coagulation necrosis achieved by standardized RF ablation in the liver increases with reduced organ perfusion and that this effect can be accurately monitored using MRI. The major factor influencing the size of the coagulation area is the portal venous flow. Occlusion of the hepatic artery alone does not significantly increase lesion size. T2w sequences are best suited for postprocedure imaging due to the high lesion-to-liver CNR in rabbits with normal hepatic perfusion. J. Magn. Reson. Imaging 2001;13:57-63. Copyright 2001 Wiley-Liss, IncDB - MEDLINE UI - 21096039 IN - Division of MRI, Department of Radiology, University Hospitals of Cleveland/Case Western Reserve University, Cleveland, Ohio 44106, USA JC - beo, BEO, BEO, 9105850 Journal Subset Index Medicus CP - United States PT - Journal Article LG - English EM - 20010426. Entry Week: 20010426 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 1053-18071 f`Effect of vascular occlusion on radiofrequency ablation of the liver: results in a porcine modelhaChinn,S.B. Lee,F.T.,Jr. Kennedy,G.D. Chinn,C. Johnson,C.D. Winter,T.C.,III Warner,T.F. Mahvi,D.M.9 2001 3/2001*Catheter Ablation *Hepatic Artery *Liver/su [Surgery] *Portal Vein Animal Comparative Study Constriction Female Liver Liver/pa [Pathology] methods Necrosis Portal Vein Swine Temperature Time Factors United States Hepatic Artery789-795b,%AJR.American Journal of Roentgenologye 176d3sLesion size, uniformity, and roundness: Pringle > Portal Vein > Hepatic artery > no occlusion. Time at lethal temp: any occlusion> no occlusionlOBJECTIVE: This study determined the effect of vascular occlusion on radiofrequency lesion shape, volume, and temperature in a porcine liver model. SUBJECTS AND METHODS: Radiofrequency lesions (n = 33) were created in the livers of six domestic pigs in vivo using a multiprong radiofrequency electrode. Lesions were randomly assigned to one of four vascular occlusion groups: portal vein, hepatic artery, Pringle maneuver (both hepatic artery and portal vein), or no occlusion. Radiofrequency parameters were time, 7 min; power, 50 W; and target temperature, 100 degrees C. Temperatures were measured 5, 10, and 15 mm from the electrode. After the animals were sacrificed, the lesions were excised. Lesion volume, diameter, and shape; maximum temperature; and time exposed to lethal temperatures (42-60 degrees C) were determined. RESULTS: Lesion volume was greatest with the Pringle maneuver lesions (12.6 +/- 4.8 cm(3)), followed by occlusion of the portal vein (8.6 +/- 3.8 cm(3)), occlusion of the hepatic artery (7.6 +/- 2.9 cm(3)), and no occlusion (4.3 +/- 1.0 cm(3)) (p < 0.05). Maximum lesion diameter was similar with the Pringle maneuver (3.3 +/- 0.3 cm), the portal vein (3.3 +/- 0.2 cm), and the hepatic artery (3.2 +/- 0.2 cm) groups compared with no occlusion (2.6 +/- 1.0 cm) (p < 0.05). Minimum lesion diameter ranged from 2.9 cm for Pringle maneuver lesions to 1.0 cm for lesions with no occlusion (p < 0.05). Vascular occlusion increased the time tissue was exposed to lethal temperatures (> 42-60 degrees C) and created more spherical lesions than no occlusion. CONCLUSION: Vascular occlusion combined with radiofrequency ablation increases the volume of necrosis, creates a more spherical lesion, and increases the time tissue is exposed to lethal temperatures when compared with radiofrequency alone. Most of this vascular occlusion effect could be accomplished with hepatic artery occlusion alonepjDB - MEDLINE UI - 21123858 IN - Department of Radiology, E3/311 CSC, University of Wisconsin, 600 Highland Ave., Madison, WI 53792, USA JC - 3ae, 3AE, 3AE, 7708173 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 20010426. Entry Week: 20010426 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0361-803X  547voPercutaneous radiofrequency tissue ablation: does perfusion-mediated tissue cooling limit coagulation necrosis?xrGoldberg,S.N. Hahn,P.F. Tanabe,K.K. Mueller,P.R. Schima,W. Athanasoulis,C.A. Compton,C.C. Solbiati,L. Gazelle,G.S. 1998 1/1998*Catheter Ablation/mt [Methods] *Hypothermia,Induced *Liver Neoplasms/sc [Secondary] *Liver Neoplasms/su [Surgery] *Liver/bs [Blood Supply] 0 (Vasoconstrictor Agents) 0 (Vasopressins) Aged Animal Balloon Dilatation Balloon Occlusion blood Cattle Colorectal Neoplasms/bs [Blood Supply] Colorectal Neoplasms/pa [Pathology] Constriction,Pathologic Electrodes Female Follow-Up Studies Hepatic Artery Hepatic Artery/de [Drug Effects] Hepatic Artery/pp [Physiopathology] Human Liver Liver Neoplasms/bs [Blood Supply] Liver/pa [Pathology] Liver/su [Surgery] methods Necrosis Perfusion Portal Vein Portal Vein/de [Drug Effects] Portal Vein/pp [Physiopathology] Support,Non-U.S.Gov't Swine United States Vasoconstrictor Agents/pd [Pharmacology] Vasopressins/pd [Pharmacology] t-114.Journal of Vascular & Interventional Radiology9 1:Pt 1Pig in vivo, cooled tip. Balloon occlusion of portal vein, celiac artery or hepatic artery created larger lesions; vasopressin infusion alone had smaller lesions, but vasopressin with occlusion had largest lesion. Temperature profile measued with and without Pringle. Temperature peak was higher and lasted much longer after cessation of current. In vivo human, 7 patients had greater lesion with portal inflow occlusion.F?PURPOSE: To determine, by decreasing hepatic perfusion during radiofrequency (RF) ablation, whether perfusion-mediated tissue cooling can explain the reduced coagulation observed in in vivo studies compared to that seen with RF application in ex vivo tissue. MATERIALS AND METHODS: RF was applied in vivo with use of cooled-tip electrodes to normal porcine liver without (n = 8) and with balloon occlusion of the portal vein (n = 8), celiac artery (n = 3), or hepatic artery (n = 2), and to ex vivo calf liver (n = 10). In vivo trials of vasopressin (0.3-0.6 U/min) infusion during RF application with (n = 10) and without (n = 2) arterial balloon occlusion were also performed. Intraoperative RF was subsequently performed in seven patients with hepatic colorectal metastases with and without portal inflow occlusion. Remote thermometry was performed in four patients. RESULTS: RF application (12 minutes) during portal venous occlusion produced larger areas of coagulation necrosis than RF with unaltered blood flow (2.9 cm +/- 0.1 vs 2.4 cm +/- 0.2 diameter; P < .01). With celiac and hepatic artery occlusion, coagulation diameter measured 2.7 cm +/- 0.2 and 2.5 cm +/- 0.1, respectively. Infusion of vasopressin without vascular occlusion reduced coagulation diameter to 1.1 cm. However, different methods of hepatic or celiac arterial balloon occlusion with simultaneous vasopressin infusion produced a mean 3.4 cm +/- 0.2 of necrosis. Coagulation in ex vivo liver was 2.9 cm +/- 0.1 in diameter. Clinical studies demonstrated greater coagulation diameter for metastases treated during portal inflow occlusion (4.0 cm +/- 1.3) than for tumors treated with normal blood flow (2.5 cm +/- 0.8; P < .05). Thermometry documented a 10 degrees C increase compared to baseline at 10 mm and 20 mm from the electrode after 5 minutes of portal inflow occlusion during constant RF application. CONCLUSIONS: Perfusion-mediated tissue cooling reduces coagulation necrosis achievable with RF ablation. Reduction of blood flow during RF application increases coagulation in both an animal model and human liver metastases~xDB - MEDLINE UI - 98127921 IN - Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA JC - ber, BER, BER, 9203369 Journal Subset Index Medicus CP - United States PT - Journal Article LG - English EM - 19980316 Revised: 20001218. Entry Week: 19980316 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 1051-0443 272piRadio-frequency tissue ablation: effect of pharmacologic modulation of blood flow on coagulation diameterGB