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Zhang M, Cheng Y, Liu H, Nan Q. Study on the effect of different blood flow velocities of pulmonary vein on endocardial microwave ablation of atrial fibrillation. Technol Health Care 2021; 30:29-41. [PMID: 33998563 DOI: 10.3233/thc-202421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To cure atrial fibrillation, the maximum ablation depth (⩾ 50∘C) should exceed the myocardial thickness to achieve the effect of transmural ablation. The blood flow of pulmonary vein in the endocardium can cause the change in the myocardial temperature distribution. Therefore, the study investigated the effect of different pulmonary vein blood flow velocities on the endocardial microwave ablation. METHODS The finite element model of the endocardial microwave ablation of pulmonary vein was simulated by electromagnetic thermal flow coupling. The ablation power was 30 W and the ablation time was within 30 s. The blood flow in the coupling of fluid mechanics equation and heat transfer equation results in the heat damage. Furthermore, the cause of the different lesion dimensions is the blood flow velocity. The flow velocities were set as 0, 0.02, 0.05, 0.07, 0.12, 0.16, 0.20, 0.25 and 0.30 m/s. RESULTS When the flow velocities were 0, 0.02, 0.05, 0.07, 0.12, 0.16, 0.20, 0.25 and 0.30 m/s, the maximum ablation depth were 6.0, 5.56, 5.16, 5.12, 5.04, 5.01, 4.98, 4.96 and 4.94 mm, respectively; the maximum ablation width were 12.52, 9.63, 9.23, 9.16, 9.07, 9.05, 8.94, 8.91, 8.90 mm, respectively; the maximum ablation length were 12.00, 11.61, 8.98, 8.59, 8.37, 8.23, 8.16, 8.06 and 8.04 mm respectively. To achieve transmural ablation, the time was 3, 3, 3, 3, 3, 4, 4, 4, 4 s, respectively when the myocardial thickness was 2 mm; the time was 7, 8, 8, 8, 9, 9, 9, 9, 9 s, respectively when 3 mm; the time was 15, 16, 18, 19, 19, 20, 20, 20, 20 s, respectively when 4 mm. CONCLUSIONS When the velocity increases from 0 m/s to 3 m/s, the microwave lesion depth decreases by 1.06 mm. To achieve transmural ablation, when the myocardial thickness is 2 mm, 3 and 4 s should be taken when the velocity is 0-0.12 and 0.120.30 m/s, respectively; when the myocardial thickness is 3 mm, 7, 8 and 9 s should be taken when 0, 0-0.07 and 0.07-0.30 m/s respectively; when the myocardial thickness is 4 mm, 15, 16, 18, 19, 20 s should be taken when 0, 0-0.02, 0.02-0.05, 0.05-0.12, 0.12 m/s-0.30 m/s.
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Epicardial, Biatrial Ablation with Integrated Uni-Bipolar Radiofrequency Technology in Stand-Alone Persistent Atrial Fibrillation. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2019; 13:114-119. [DOI: 10.1097/imi.0000000000000482] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Objective Although minimally invasive approaches for surgical treatment of stand-alone atrial fibrillation have gained popularity for the past decade, ablation technology and extensive lesion sets play a major role in the achievement of a successful procedure, especially in presence of persistent and long-standing persistent atrial fibrillation. We evaluated clinical outcomes after totally endoscopic biatrial epicardial ablation of persistent atrial fibrillation with a novel integrated uni-bipolar radiofrequency device. Methods Forty-nine (49) consecutive patients with stand-alone atrial fibrillation underwent right-sided monolateral thoracoscopic surgical ablation with a novel integrated uni-bipolar radiofrequency energy delivery and temperature-controlled technology. Atrial fibrillation was persistent in 13 (26.5%) of 49 and long-standing persistent in 36 (73.5%) of 49 patients. Mean ± SD age was 60.6 ± 10.3 years. Median duration of atrial fibrillation was 74 months. Mean ± SD left atrial diameter was 44.7 ± 4.0 mm. Results Epicardial en bloc isolation of all pulmonary veins (box lesion) and additional ablation of the right atrial free wall was successfully performed via minimally invasive approach without any intraoperative and postoperative major complications. Intraoperative entrance and exit block was achieved in 77.5% (38/49) and 91.8% (45/49) of patients, respectively. Mean ± SD ablation time was 16.3 ± 4.8 minutes. No intensive care unit stay was required. Postoperative sinus rhythm was achieved in 93.8% (30/32) patients, and no pacemaker implantation was required. At 13 months, 87.7% (43/49) of patients were in sinus rhythm; 71.4% (35/49) were free from antiarrhythmic drugs and 75.5% (37/49) from oral anticoagulation. Conclusions Integrated uni-bipolar radiofrequency ablation technology showed to be effective for the surgical treatment of atrial fibrillation with a total endoscopic approach. A versapolar suction device with extensive right-left atrial lesion set may further improve outcomes in patients with nonparoxysmal atrial fibrillation.
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Ramírez AS, Rodríguez PÁ, Gutiérrez SVE, Ávila OG. Preliminary experience in the management of brain and skull-base tumors with microwave ablation; feasibility guided by ultrasound, report from 23 cases. Surg Neurol Int 2019; 10:17. [PMID: 31123624 PMCID: PMC6416755 DOI: 10.4103/sni.sni_361_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 12/19/2018] [Indexed: 11/04/2022] Open
Abstract
Background In surgery involving brain tumors, the use of new tools or equipment that allows for better results and improvement in the quality of life of the patients is mandatory. Microwave ablation (MWA) is a technique that has been used effectively since 1994 in the management of different kinds of tumors. The authors present their surgical experience with 23 cases of brain and skull-base tumors using MWA technique. Methods In all, 23 cases diagnosed with brain and skull-base tumors are described; all of these were treated with MWA as unique technique as a complement to conventional microsurgical tumor resection. In all cases, ultrasound imaging guidance was used. A thin antenna (caliber 14.5; MedWaves) was positioned through ultrasound images to a central intratumoral area, and then energy was applied for 1-3 min until the temperature sensor in the proximal position of the antenna reached 80-100°C. Through transoperative Doppler ultrasound images and surgical microscopy, changes in the generated ablation were observed. The said ablation led to a decrease in intratumoral blood flow, and the adjacent vascular and cerebral structures were preserved. Results The application of MWA during brain surgery was regarded as safe in all cases, as no permanent additional neurological deficit was detected. Intratumoral vascular flow was also reduced and tumor resection was facilitated. Likewise, a reduction in tumor volume was noted, and in others in whom the ablation was applied as a single therapy, a progressive destruction of the tumor was observed. Conclusion MWA can be a useful tool as a single therapy or as a complement to conventional techniques for the surgical resection of brain and skull-base tumors. It was a safe method in all cases, producing a decrease in intratumoral blood flow, and this procedure facilitates the microsurgical resection of the lesion.
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Affiliation(s)
- Adrián Santana Ramírez
- Department of Neurosurgery, Hospital Civil "Dr. Juan I. Menchaca", Guadalajara, Jalisco, México
| | - Pedro Ávila Rodríguez
- Department of Neurosurgery, Hospital Civil "Dr. Juan I. Menchaca", Guadalajara, Jalisco, México
| | | | - Oscar Gutiérrez Ávila
- Department of Neurosurgery, Hospital Civil "Dr. Juan I. Menchaca", Guadalajara, Jalisco, México
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Wide Variations in Energy Delivery Using an Impedance-Controlled Algorithm in Bipolar Radiofrequency Ablation: Evidence against Fixed Time Ablation. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2019; 2:67-72. [DOI: 10.1097/imi.0b013e31803c9b11] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Objective Bipolar radiofrequency ablation recently has been used to replace many of the incisions of the Cox-Maze procedure in the surgical treatment of atrial fibrillation. The unique aspect of this technology is that it uses an algorithm based on changes in tissue conductance to determine the energy required to achieve a transmural lesion instead of relying on predetermined time and/or temperature criteria to determine ablation duration, as with most other ablation technologies. The purpose of this study was to determine variations in the different parameters of ablation needed to create transmural lesions in human atria. Methods Initial impedance, total energy, temperature, and ablation time were measured in 38 patients undergoing surgery, using an impedance-controlled bipolar radiofrequency device (AtriCure Isolator, Cincinnati, OH). Lesions were categorized into the following groups: right atrial free wall, left atrial free wall, atrium up to mitral valve annulus, atrium up to tricuspid valve annulus, and right or left pulmonary veins. Results There was a wide range of initial impedance (32.3 to 760.7 Ohms), and this correlated with total energy delivered (r = −0.31, P = 0.002). Ablation times varied widely (2.0 to 29.9 seconds) and were longer on left atrial structures than right (P < 0.005) and shortest near the tricuspid annulus (P < 0.001). Mean tissue temperature 1 mm from the electrode was only 45.7 ± 7.8°C (range, 23.7°C to 69.3°C). Conclusions Bipolar ablation of different atrial structures required widely different amounts of energy and ablation times, probably as the result of the inhomogeneity of atrial geometry and tissue impedance. These data cast doubt on the efficacy of any fixed-time or temperature ablations in the clinical setting.
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Rosati F, Muneretto C, Merati E, Polvani G, Moltrasio M, Tondo C, Curnis A, Cerini M, Metras A, Bisleri G. Epicardial, Biatrial Ablation with Integrated Uni-Bipolar Radiofrequency Technology in Stand-Alone Persistent Atrial Fibrillation. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2018. [DOI: 10.1177/155698451801300207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Fabrizio Rosati
- Division of Cardiac Surgery, Queen's University, Kingston, ON Canada
| | - Claudio Muneretto
- Division of Cardiac Surgery, University of Brescia Medical School, Brescia, Italy
| | - Elisa Merati
- Division of Cardiac Surgery, University of Milan, Milan, Italy
| | | | | | - Claudio Tondo
- Division of Cardiology, University of Milan, Milan, Italy
| | - Antonio Curnis
- Division of Cardiology, University of Brescia Medical School, Brescia, Italy
| | - Manuel Cerini
- Division of Cardiology, University of Brescia Medical School, Brescia, Italy
| | - Alexandre Metras
- Division of Cardiovascular Surgery, CHU Bordeaux Hopital Haut-Leveque, Bordeaux, France
| | - Gianluigi Bisleri
- Division of Cardiac Surgery, Queen's University, Kingston, ON Canada
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Strategies to Improve the Efficacy of Epicardial Linear Ablation on the Beating Heart. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2017; 11:414-419. [PMID: 27930603 DOI: 10.1097/imi.0000000000000319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Creating transmural linear lesions on the beating heart is an important component of minimally invasive surgical ablation for atrial fibrillation. Animal studies have shown poor efficacy for surface bipolar radiofrequency ablation (RFA). Clinicians have developed strategies including multiple device applications and vena caval occlusion (VCO) to improve ablation efficacy. These techniques were evaluated in an acute porcine model. METHODS In the first experiment, an RFA device was used to perform two 40-second epicardial ablations on the right atrium of six pigs. Ablations were performed with and without VCO. Ultrasonic flow probes were used to verify VCO. In the second experiment, an RFA device was used to perform two 40-second epicardial ablations at six locations on the left and right atria of six pigs. All animals were sacrificed. The hearts were removed and stained with 2,3,5-triphenyltetrazolium chloride. Sections were examined using digital photography. RESULTS With VCO, 42 (81%) of 52 sections were transmural; without VCO on the RA, only 12 (24%) of 50 sections were transmural (P < 0.01). In thick (>2 mm) tissue, 10 (59%) of 17 VCO sections were transmural compared with only two (8%) of 24 with normal caval blood flow. Compared with a single ablation, multiple device applications improved transmurality on the LA but not the RA (92% vs 71%, P < 0.05). CONCLUSIONS In an acute animal model, VCO improved the efficacy of beating-heart RFA on the RA. Multiple device applications improved the efficacy of RFA on the LA.
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Watanabe Y, Schill MR, Kazui T, Melby SJ, Schuessler RB, Damiano RJ. Strategies to Improve the Efficacy of Epicardial Linear Ablation on the Beating Heart. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2016. [DOI: 10.1177/155698451601100608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Yoshiyuki Watanabe
- Department of Cardiovascular Surgery, Nippon Medical School, Chiba Hokusoh Hospital, Tokyo, Japan
| | - Matthew R. Schill
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Toshinobu Kazui
- Division of Cardiothoracic Surgery, University of Arizona Medical Center, Tucson, AZ USA
| | - Spencer J. Melby
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Richard B. Schuessler
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Ralph J. Damiano
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
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Carberry GA, Nocerino E, Mason PJ, Schwahn DJ, Hetzel S, Turnquist AM, Lee FT, Brace CL. Pulmonary Microwave Ablation Near the Heart: Antenna Positioning Can Mitigate Cardiac Complications in a Porcine Model. Radiology 2016; 282:892-902. [PMID: 27732159 DOI: 10.1148/radiol.2016160831] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Purpose To determine how close to the heart pulmonary microwave ablation can be performed without causing cardiac tissue injury or significant arrhythmia. Materials and Methods The study was performed with approval from the institutional animal care and use committee. Computed tomographic fluoroscopically guided microwave ablation of the lung was performed in 12 swine. Antennas were randomized to either parallel (180° ± 20°) or perpendicular (90° ± 20°) orientation relative to the heart surface and to distances of 0-10 mm from the heart. Ablations were performed at 65 W for 5 minutes or until a significant arrhythmia (asystole, heart block, bradycardia, supraventricular or ventricular tachycardia) developed. Heart tissue was evaluated with vital staining and histologic examination. Data were analyzed with mixed effects logistic regression, receiver operating characteristic curves, and the Fisher exact test. Results Thirty-four pulmonary microwave ablations were performed with the antenna a median distance of 4 mm from the heart in both perpendicular (n = 17) and parallel (n = 17) orientation. Significant arrhythmias developed during six (18%) ablations. Cardiac tissue injury occurred with 17 ablations (50%). Risk of arrhythmia and tissue injury decreased with increasing antenna distance from the heart with both antenna orientations. No cardiac complication occurred with a distance of greater than or equal to 4.4 mm from the heart. The ablation zone extended to the pleural surface adjacent to the heart in 71% of parallel and 17% of perpendicular ablations performed 5-10 mm from the heart. Conclusion Microwave lung ablations performed more than or equal to 5 mm from the heart were associated with a low risk of cardiac complications. © RSNA, 2016.
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Affiliation(s)
- George A Carberry
- From the Departments of Radiology (G.A.C., E.N., A.M.T., F.T.L.), Cardiology (P.J.M.), and Biomedical Engineering (C.L.B.), University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; and Research Animal Resources Center (D.J.S.) and Department of Biostatistics (S.H.), University of Wisconsin-Madison, Madison, Wis
| | - Elisabetta Nocerino
- From the Departments of Radiology (G.A.C., E.N., A.M.T., F.T.L.), Cardiology (P.J.M.), and Biomedical Engineering (C.L.B.), University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; and Research Animal Resources Center (D.J.S.) and Department of Biostatistics (S.H.), University of Wisconsin-Madison, Madison, Wis
| | - Peter J Mason
- From the Departments of Radiology (G.A.C., E.N., A.M.T., F.T.L.), Cardiology (P.J.M.), and Biomedical Engineering (C.L.B.), University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; and Research Animal Resources Center (D.J.S.) and Department of Biostatistics (S.H.), University of Wisconsin-Madison, Madison, Wis
| | - Denise J Schwahn
- From the Departments of Radiology (G.A.C., E.N., A.M.T., F.T.L.), Cardiology (P.J.M.), and Biomedical Engineering (C.L.B.), University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; and Research Animal Resources Center (D.J.S.) and Department of Biostatistics (S.H.), University of Wisconsin-Madison, Madison, Wis
| | - Scott Hetzel
- From the Departments of Radiology (G.A.C., E.N., A.M.T., F.T.L.), Cardiology (P.J.M.), and Biomedical Engineering (C.L.B.), University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; and Research Animal Resources Center (D.J.S.) and Department of Biostatistics (S.H.), University of Wisconsin-Madison, Madison, Wis
| | - Alyssa M Turnquist
- From the Departments of Radiology (G.A.C., E.N., A.M.T., F.T.L.), Cardiology (P.J.M.), and Biomedical Engineering (C.L.B.), University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; and Research Animal Resources Center (D.J.S.) and Department of Biostatistics (S.H.), University of Wisconsin-Madison, Madison, Wis
| | - Fred T Lee
- From the Departments of Radiology (G.A.C., E.N., A.M.T., F.T.L.), Cardiology (P.J.M.), and Biomedical Engineering (C.L.B.), University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; and Research Animal Resources Center (D.J.S.) and Department of Biostatistics (S.H.), University of Wisconsin-Madison, Madison, Wis
| | - Christopher L Brace
- From the Departments of Radiology (G.A.C., E.N., A.M.T., F.T.L.), Cardiology (P.J.M.), and Biomedical Engineering (C.L.B.), University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; and Research Animal Resources Center (D.J.S.) and Department of Biostatistics (S.H.), University of Wisconsin-Madison, Madison, Wis
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QIAN PIERRE, BARRY MICHAELANTHONY, NGUYEN TRANG, ROSS DAVID, KOVOOR PRAMESH, MCEWAN ALISTAIR, THOMAS STUART, THIAGALINGAM ARAVINDA. A Novel Microwave Catheter Can Perform Noncontact Circumferential Endocardial Ablation in a Model of Pulmonary Vein Isolation. J Cardiovasc Electrophysiol 2015; 26:799-804. [DOI: 10.1111/jce.12683] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 03/10/2015] [Accepted: 04/02/2015] [Indexed: 11/28/2022]
Affiliation(s)
- PIERRE QIAN
- Cardiology Department; Westmead Hospital; Sydney Australia
| | | | - TRANG NGUYEN
- Cardiology Department; Westmead Hospital; Sydney Australia
- School of Electrical and Information Engineering; University of Sydney; Sydney Australia
| | - DAVID ROSS
- Cardiology Department; Westmead Hospital; Sydney Australia
- Sydney Medical School; University of Sydney; Sydney Australia
| | - PRAMESH KOVOOR
- Cardiology Department; Westmead Hospital; Sydney Australia
- Sydney Medical School; University of Sydney; Sydney Australia
| | - ALISTAIR MCEWAN
- Cardiology Department; Westmead Hospital; Sydney Australia
- School of Electrical and Information Engineering; University of Sydney; Sydney Australia
| | - STUART THOMAS
- Cardiology Department; Westmead Hospital; Sydney Australia
- Sydney Medical School; University of Sydney; Sydney Australia
| | - ARAVINDA THIAGALINGAM
- Cardiology Department; Westmead Hospital; Sydney Australia
- Sydney Medical School; University of Sydney; Sydney Australia
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Performance of a novel bipolar/monopolar radiofrequency ablation device on the beating heart in an acute porcine model. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2014; 8:276-83. [PMID: 24145972 DOI: 10.1097/imi.0b013e3182a77f2b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Although the advent of ablation technology has simplified and shortened surgery for atrial fibrillation, only bipolar clamps have reliably been able to create transmural lesions on the beating heart. Currently, there are no devices capable of reproducibly creating the long linear lesions in the right and left atria needed to perform a Cox-Maze procedure. This study evaluated the performance of a novel suction-assisted radiofrequency device that uses both bipolar and monopolar energy to create lesions from an epicardial approach on the beating heart. METHODS Six domestic pigs underwent median sternotomy. A dual bipolar/monopolar radiofrequency ablation device was used to create epicardial linear lesions on the superior and inferior vena cavae, the right and left atrial free walls, and the right and left atrial appendages. The heart was stained with 2,3,5-triphenyl-tetrazolium chloride, and each lesion was cross-sectioned at 5-mm intervals. Lesion depth and transmurality were determined. RESULTS Transmurality was documented in 94% of all cross sections, and 68% of all ablation lines were transmural along their entire length. Tissue thickness was not different between the transmural and nontransmural cross sections (3.1 ± 1.3 and 3.4 ± 2.1, P = 0.57, respectively), nor was the anatomic location on the heart (P = 0.45 for the distribution). Of the cross sections located at the end of the ablation line, 11% (8/75) were found to be nontransmural, whereas only 4% (8/195) of the cross sections located within the line of ablation were found to be nontransmural (P = 0.04). Logistic regression analysis demonstrated that failure of the device to create transmural lesions was associated with low body temperature (P = 0.006) but not with cardiac output (P = 0.54). CONCLUSIONS This novel device was able to consistently create transmural epicardial lesions on the beating heart, regardless of anatomic location, cardiac output, or tissue thickness. The performance of this device was improved over most devices previously tested but still falls short of ideal clinical performance. Transmurality was lower at the end of the lesions, highlighting the importance of overlapping lines of ablation in the clinical setting.
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Watanabe Y, Weimar T, Kazui T, Lee U, Schuessler RB, Damiano RJ. Epicardial ablation performance of a novel radiofrequency device on the beating heart in pigs. Ann Thorac Surg 2014; 97:673-8. [PMID: 24484804 DOI: 10.1016/j.athoracsur.2013.10.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 10/03/2013] [Accepted: 10/07/2013] [Indexed: 11/24/2022]
Abstract
PURPOSE Only bipolar clamps create reliable transmural lesions on the beating heart. This study evaluated the performance of a new radiofrequency (RF) device on the beating heart in an acute porcine model. DESCRIPTION Six domestic pigs were ablated with a novel bipolar RF linear device on the beating heart (ablation time of 40 s, 3 each on right and left atria and 1 each on superior and inferior vena cavae). The heart was stained with 2, 3, 5-triphenyl-tetrazolium chloride, and each lesion was cross-sectioned for lesion depth and transmurality. EVALUATION Transmurality was documented in 89% of the cross-sections. Sixty-three percent of lesions were transmural along the entire lesion length. Overall, 85% of the nontransmural cross-sections were located on the right atrium, and half of the nontransmural sections were in the superior or inferior vena cavae lesions. CONCLUSIONS This novel device was able to create transmural lesions on the beating heart, more effectively in the left atrium than in the right atrium.
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Affiliation(s)
- Yoshiyuki Watanabe
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, Missouri
| | - Timo Weimar
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, Missouri
| | - Toshinobu Kazui
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, Missouri
| | - Urvi Lee
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, Missouri
| | - Richard B Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, Missouri
| | - Ralph J Damiano
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, Missouri.
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Saint LL, Lawrance CP, Okada S, Kazui T, Robertson JO, Schuessler RB, Damiano RJ. Performance of a Novel Bipolar/Monopolar Radiofrequency Ablation Device on the Beating Heart in an Acute Porcine Model. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2013. [DOI: 10.1177/155698451300800406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Lindsey L. Saint
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Christopher P. Lawrance
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Shoichi Okada
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Toshinobu Kazui
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Jason O. Robertson
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Richard B. Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
| | - Ralph J. Damiano
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO USA
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Neelakanta PS, Sharma B. Conceiving THz Endometrial Ablation: Feasibility, Requirements and Technical Challenges. IEEE J Biomed Health Inform 2013; 17:813-9. [DOI: 10.1109/jbhi.2013.2267352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
Microwave tissue heating is being increasingly utilised in several medical applications, including focal tumour ablation, cardiac ablation, haemostasis and resection assistance. Computational modelling of microwave ablations is a precise and repeatable technique that can assist with microwave system design, treatment planning and procedural analysis. Advances in coupling temperature and water content to electrical and thermal properties, along with tissue contraction, have led to increasingly accurate computational models. Developments in experimental validation have led to broader acceptability and applicability of these newer models. This review will discuss the basic theory, current trends and future direction of computational modelling of microwave ablations.
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Affiliation(s)
- Jason Chiang
- Department of Radiology, University of Wisconsin – Madison, Madison WI
- Department of Biomedical Engineering, University of Wisconsin – Madison, Madison WI
| | - Peng Wang
- Department of Radiology, University of Wisconsin – Madison, Madison WI
| | - Christopher L. Brace
- Department of Radiology, University of Wisconsin – Madison, Madison WI
- Department of Biomedical Engineering, University of Wisconsin – Madison, Madison WI
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Jönsson A, Lehto M, Ahn H, Hermansson U, Linde P, Ahlsson A, Koistinen J, Savola J, Raatikainen P, Lepojärvi M, Sahlman A, Werkkala K, Toivonen L, Walfridsson H. Microwave Ablation in Mitral Valve Surgery for Atrial Fibrillation (MAMA). J Atr Fibrillation 2012; 5:432. [PMID: 28496753 DOI: 10.4022/jafib.432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 02/27/2012] [Accepted: 02/27/2012] [Indexed: 11/10/2022]
Abstract
Objective: Microwave ablation in conjunction with open heart surgery is effective in restoring sinus rhythm (SR) in patients with atrial fibrillation (AF). In patients assigned for isolated mitral valve surgery no prospective randomized trial has reported its efficacy. Methods: 70 patients with longlasting AF where included from 5 different centres. They were randomly assigned to mitral valve surgery and atrial microwave ablation or mitral valve surgery alone. Results: Out of 70 randomized, 66 and 64 patients were available for evaluation at 6 and 12 months. At 12 months SR was restored and preserved in 71.0 % in the ablation group vs 36.4 % in the control group (P=0.006), corresponding figures at 6 months was 62.5 % vs 26.5 % (P=0.003). The 30-day mortality rate was 1.4 %, with one death in the ablation group vs zero deaths in the control group. At 12 months the mortality rate was 7,1 % (Ablation n=3 vs Control n=2). No significant differences existed between the groups with regard to the overall rate of serious adverse events (SAE) during the perioperative period or at the end of the study. 16 % of patients randomized to ablation were on antiarrhytmic drugs compared to 6 % in the control group after 1 year (p=0.22). Conclusion: Microwave ablation of left and right atrium in conjunction with mitral valve surgery is safe and effectively restores sinus rhythm in patients with longlasting AF as compared to mitral valve surgery alone.
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Affiliation(s)
- Anders Jönsson
- Department of Cardiology, Linnköping University Hospital, Linnköping, Sweden
| | - Mika Lehto
- Department of Cardiology, Helsinki University Hospital, Helsinki, Finland
| | - Henrik Ahn
- Department of Cardiothoracic Surgery, Linnköping University Hospital, Linnköping, Sweden
| | - Ulf Hermansson
- Department of Cardiothoracic Surgery, Linnköping University Hospital, Linnköping, Sweden
| | - Peter Linde
- Department of Cardiology, Örebro University Hospital, Örebro, Sweden
| | - Anders Ahlsson
- Department of Cardiothoracic Surgery, Örebro University Hospital, Örebro, Sweden
| | - Juhani Koistinen
- Department of Cardiology, Turku University Hospital, Turku, Finland
| | - Jukka Savola
- Department of Cardiothoracic Surgery, Turku University Hospital, Turku, Finland
| | | | - Martti Lepojärvi
- Department of Cardiothoracic Surgery, Oulu University Hospital, Oulu, Finland
| | - Antero Sahlman
- Department of Cardiothoracic Surgery, Helsinki University Hospital, Helsinki, Finland
| | - Kalervo Werkkala
- Department of Cardiothoracic Surgery, Helsinki University Hospital, Helsinki, Finland
| | - Lauri Toivonen
- Department of Cardiology, Helsinki University Hospital, Helsinki, Finland
| | - Håkan Walfridsson
- Department of Cardiology, Linnköping University Hospital, Linnköping, Sweden
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Schuessler RB, Lee AM, Melby SJ, Voeller RK, Gaynor SL, Sakamoto SI, Damiano RJ. Animal studies of epicardial atrial ablation. Heart Rhythm 2011; 6:S41-5. [PMID: 19959142 DOI: 10.1016/j.hrthm.2009.07.028] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Indexed: 11/25/2022]
Abstract
The Cox maze procedure is an effective treatment of atrial fibrillation, with a long-term freedom from recurrence greater than 90%. The original procedure was highly invasive and required cardiopulmonary bypass. Modifications of the procedure that eliminate the need for cardiopulmonary bypass have been proposed, including use of alternative energy sources to replace cut-and-sew lesions with lines of ablation made from the epicardium on the beating heart. This has been challenging because atrial wall muscle thickness is extremely variable, and the muscle can be covered with an epicardial layer of fat. Moreover, the circulating intracavitary blood acts as a potential heat sink, making transmural lesions difficult to obtain. In this report, we summarize the use of nine different unidirectional devices (four radiofrequency, two microwave, two lasers, one cryothermic) for creating continuous transmural lines of ablation from the atrial epicardium in a porcine model. We define a unidirectional device as one in which all the energy is applied by a single transducer on a single heart surface. The maximum penetration of any device was 8.3 mm. All devices except one, the AtriCure Isolator pen, failed to penetrate 2 mm in some nontransmural sections. Future development of unidirectional energy sources should be directed at increasing the maximum depth and the consistency of penetration.
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Affiliation(s)
- Richard B Schuessler
- Barnes Jewish Hospital and Division of Cardiothoracic Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
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Breda JR, Breda ASCR, Ragognette RG, Machado LN, Neff CB, De Matos LL, Meneghine A, Pires AC. Comparison of Uniatrial and Biatrial Radiofrequency Ablation Procedures in Atrial Fibrillation: Initial Results. Heart Surg Forum 2011; 14:E271-5. [DOI: 10.1532/hsf98.20101119] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
<p><b>Background:</b> Atrial fibrillation (AF) is the most commonly sustained cardiac rhythm disturbance. Surgical ablation techniques were developed involving the left atrium only and modifications of the maze procedure in ablating both atria.</p><p>Objective: The aim of this study was to compare, in patients with permanent AF, the efficacy of uniatrial versus biatrial radiofrequency ablation procedure in the treatment of chronic atrial fibrillation in patients with associated cardiac disease.</p><p><b>Method:</b> Between September 2003 and May 2009, 30 patients were submitted to the radiofrequency ablation procedure for AF associated with concomitant cardiac surgery; 15 patients underwent a uniatrial procedure, and 15 patients underwent biatrial ablation. The mean age was 47.73 � 9.85 years, and 53.4% were men. The average followup time was 12.16 � 10.89 months for the uniatrial group and 7.0 � 4.0 months for the biatrial group.</p><p><b>Results:</b> Neither hospital mortality nor complications related to radiofrequency ablation were was registered. At the time of hospital discharge, 9 patients (60%) were in a state of sinus rhythm in both groups. However, patients undergoing biatrial ablation (range 73.3% versus 46.7%) demonstrated complete freedom from atrial fibrillation at all times.</p><p><b>Conclusion:</b> Biatrial ablation surgical procedures were more effective in controlling atrial fibrillation than procedures limited to the left atrium.</p>
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Fontan conversion with novel direct ablation after childbirth: report of a case. Surg Today 2011; 41:1684-8. [PMID: 21969207 DOI: 10.1007/s00595-011-4560-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 05/09/2011] [Indexed: 10/17/2022]
Abstract
A 38-year-old woman underwent atriopulmonary Fontan surgery at age 18 years and subsequently successfully delivered a girl by cesarean section at age 34. Her condition later deteriorated due to atrial tachyarrhythmia and progressed to New York Heart Association (NYHA) class IV heart failure. Her treatment, at age 36, comprised total cavopulmonary connection conversion, direct right atrial ablation with bipolar radiofrequency devices, the creation of an atrial septal defect, and placement of a dual-chamber permanent pacemaker. Three years after the conversion, her condition has improved to NYHA class I.
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Iribarne A, Easterwood R, Chan EYH, Yang J, Soni L, Russo MJ, Smith CR, Argenziano M. The golden age of minimally invasive cardiothoracic surgery: current and future perspectives. Future Cardiol 2011; 7:333-46. [PMID: 21627475 DOI: 10.2217/fca.11.23] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Over the past decade, minimally invasive cardiothoracic surgery (MICS) has grown in popularity. This growth has been driven, in part, by a desire to translate many of the observed benefits of minimal access surgery, such as decreased pain and reduced surgical trauma, to the cardiac surgical arena. Initial enthusiasm for MICS was tempered by concerns over reduced surgical exposure in highly complex operations and the potential for prolonged operative times and patient safety. With innovations in perfusion techniques, refinement of transthoracic echocardiography and the development of specialized surgical instruments and robotic technology, cardiac surgery was provided with the necessary tools to progress to less invasive approaches. However, much of the early literature on MICS focused on technical reports or small case series. The safety and feasibility of MICS have been demonstrated, yet questions remain regarding the relative efficacy of MICS over traditional sternotomy approaches. Recently, there has been a growth in the body of published literature on MICS long-term outcomes, with most reports suggesting that major cardiac operations that have traditionally been performed through a median sternotomy can be performed through a variety of minimally invasive approaches with equivalent safety and durability. In this article, we examine the technological advancements that have made MICS possible and provide an update on the major areas of cardiac surgery where MICS has demonstrated the most growth, with consideration of current and future directions.
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Affiliation(s)
- Alexander Iribarne
- Division of Cardiothoracic Surgery, Department of Surgery, College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA
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Damiano RJ. Surgical Innovation in the Information Age the Heavy Burden of Great Potential. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2011. [DOI: 10.1177/155698451100600501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Ralph J. Damiano
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine; Barnes-Jewish Hospital, St. Louis, MO USA
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Surgical Innovation in the Information Age the Heavy Burden of Great Potential. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2011; 6:283-8. [DOI: 10.1097/imi.0b013e318237131f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Villamizar NR, Crow JH, Piacentino V, DiBernardo LR, Daneshmand MA, Bowles DE, Groh MA, Milano CA. Reproducibility of left atrial ablation with high-intensity focused ultrasound energy in a calf model. J Thorac Cardiovasc Surg 2010; 140:1381-7.e1. [PMID: 20934725 PMCID: PMC4165600 DOI: 10.1016/j.jtcvs.2010.08.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/03/2010] [Accepted: 08/13/2010] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Achieving transmural tissue ablation might be necessary for successful treatment of atrial fibrillation. The purpose of this study was to evaluate the reproducibility of transmural left atrial ablation using a high-intensity focused ultrasound energy system in a calf model. METHODS Nine heparinized bovines underwent a beating-heart left atrial ablation with a single application of the high-intensity focused ultrasound device. All animals were acutely killed, and the left atrium was fixed in formalin. Protocolized histological sections (5 μm) were obtained throughout each lesion and prepared with Masson trichrome and hematoxylin and eosin staining. Measurements were performed on a total of 359 slides from the 9 lesions. In addition, fresh left atrial tissues from 18 unused human donor hearts that did not meet the criteria for cardiac transplantation were measured at the site where the high-intensity focused ultrasound device is normally applied. RESULTS Calf left atrial thickness ranged between 2.5 and 20.1 mm, with a mean of 9.10 mm. High-intensity focused ultrasound ablation consistently produced a 100% transmural lesion in left atrial thickness up to 6 mm. In addition, a transmural lesion was observed in 91% of tissues that were up to 10 mm thick and in 85% that were up to 15 mm thick. Human left atrial thickness ranged between 1.2 to 6 mm, with a mean of 3.7 mm. CONCLUSIONS Calf left atrial thickness in this study was greater than human left atrial thickness. Human left atrial thickness is generally less than 6 mm, and in this range high-intensity focused ultrasound ablation achieved 100% transmurality. These histological results might correlate with a high success rate of atrial fibrillation ablation by using the high-intensity focused ultrasound system.
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Affiliation(s)
- Nestor R Villamizar
- Department of Surgery, Duke University Medical Center, Durham, NC 27713, USA.
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23
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Damiano RJ. Surgical ablation of lone atrial fibrillation on the beating heart: the chaos continues. Europace 2010; 12:297-8. [DOI: 10.1093/europace/eup442] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Edgerton JR, Jackman WM, Mahoney C, Mack MJ. Totally thorascopic surgical ablation of persistent AF and long-standing persistent atrial fibrillation using the “Dallas” lesion set. Heart Rhythm 2009; 6:S64-70. [DOI: 10.1016/j.hrthm.2009.09.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Indexed: 11/28/2022]
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El Oumeiri B, Poncelet AJ, El Khoury G. Why is freedom from atrial fibrillation still lower with endoscopic pulmonary vein isolation than with the Cox maze III procedure? J Thorac Cardiovasc Surg 2009; 137:1036; author reply 1036-7. [PMID: 19327542 DOI: 10.1016/j.jtcvs.2008.09.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2008] [Revised: 09/24/2008] [Accepted: 09/30/2008] [Indexed: 11/26/2022]
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26
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Lee AM, Aziz A, Sakamoto SI, Schuessler RB, Damiano RJ. Epicardial Ablation on the Beating Heart. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2009. [DOI: 10.1177/155698450900400206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Anson M. Lee
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, Saint Louis, MO USA
| | - Abdulhameed Aziz
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, Saint Louis, MO USA
| | - Shun-Ichiro Sakamoto
- Division of Cardiothoracic Surgery, Nippon Medical School, Chiba Hokusoh Hospital, Tokyo, Japan
| | - Richard B. Schuessler
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, Saint Louis, MO USA
| | - Ralph J. Damiano
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, Saint Louis, MO USA
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Epicardial Ablation on the Beating Heart: Limited Efficacy of a Novel, Cooled Radiofrequency Ablation Device. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2009; 4:86-92. [PMID: 22323899 DOI: 10.1097/imi.0b013e3181a348a2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE: To perform a minimally invasive procedure for atrial fibrillation without cardiopulmonary bypass, it is necessary to create transmural lesions on the beating heart. Although bipolar radiofrequency clamps can isolate the pulmonary veins, they have difficulty in performing any other left atrial lesions, particularly those of the traditional Cox-Maze procedure. This study examined the performance of an internally cooled, bipolar radiofrequency device designed for such an application. METHODS: Eleven domestic pigs underwent median sternotomy. Five animals had eight atrial lesions created with the radiofrequency device at times of 20, 30, 40, and 50 seconds. In six other pigs, the device was compared with another technology that has been used clinically for epicardial, beating heart ablation, the Guidant Flex 4 microwave device. The tissue was stained with 2,3,5-triphenyl-tetrazoluim chloride, and the lesions were sectioned at 5-mm intervals. Lesion width, depth, and transmurality were evaluated. RESULTS: The radiofrequency device had a linear dose-response relationship. Lesions were wider and deeper with increasing ablation times. A total of 40%, 45%, 60%, and 67% of lesions were transmural at times of 20, 30, 40, and 50 seconds, respectively. Ninety-one percent of lesions in tissue up to 4-mm thick were transmural after 50 seconds. However, performance in thicker tissue was poor. Lesions created by the device were deeper and more likely to be transmural than the Flex 4. CONCLUSIONS: This internally cooled, bipolar radiofrequency device can reliably create transmural lesions on tissue up to 4-mm thick and performs better than a microwave device.
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Sakamoto SI, Voeller RK, Melby SJ, Lall SC, Chang NL, Schuessler RB, Damiano RJ. Surgical ablation for atrial fibrillation: the efficacy of a novel bipolar pen device in the cardioplegically arrested and beating heart. J Thorac Cardiovasc Surg 2008; 136:1295-301. [PMID: 19026819 DOI: 10.1016/j.jtcvs.2008.04.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 03/18/2008] [Accepted: 04/03/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE The introduction of ablation technology has simplified surgical intervention for atrial fibrillation. However, most ablation devices cannot create focal transmural lesions on the beating heart and have difficulty ablating specific regions of the atria, such as the atrioventricular isthmus, coronary sinus, and ganglionated plexus. The purpose of this study was to examine the efficacy of a pen-type bipolar radiofrequency ablation device on both arrested and beating hearts. METHODS Endocardial and epicardial atrial tissues in the free wall, left atrial roof, atrioventricular annuli, and coronary sinus were ablated for varying time intervals (2.5-15 seconds) in porcine cardioplegically arrested (n = 6) and beating (n = 9) hearts. The hearts were stained with 1% 2,3,5-triphenyl-tetrazolium chloride solution and sectioned to determine lesion depth and width. In 5 animals epicardial fat pads containing ganglionated plexus were stimulated and ablated. RESULTS Lesion depth increased with ablation time similarly in both arrested and beating hearts. Transmurality was fully achieved in the thin atrial tissue (<4 mm) at 10 seconds in the beating and arrested hearts. The device had a maximal penetration depth of 6.1 mm. Epicardial ablation of the coronary sinus showed complete penetration through the left posterior atrium only in the arrested heart. Seven of 17 fat pads demonstrated a vagal response. All vagal responses were eliminated after ablation. CONCLUSION The bipolar pen effectively ablated atrial tissue in both arrested and beating hearts. This device might allow the surgeon to ablate tissue in regions not accessible to other devices during atrial fibrillation surgery.
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Affiliation(s)
- Shun-ichiro Sakamoto
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, MO 63110, USA
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Vicol C, Kellerer D, Petrakopoulou P, Kaczmarek I, Lamm P, Reichart B. Long-term results after ablation for long-standing atrial fibrillation concomitant to surgery for organic heart disease: is microwave energy reliable? J Thorac Cardiovasc Surg 2008; 136:1156-9. [PMID: 19026796 DOI: 10.1016/j.jtcvs.2008.05.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 02/22/2008] [Accepted: 05/09/2008] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Microwave ablation has been reported as efficient for the surgical treatment of long-standing atrial fibrillation. However, the influence of ablation lesions on long-term results is not known. METHODS From August of 2000 to November of 2003, 41 patients underwent a left atrial endocardial microwave ablation procedure after a Cox-Maze-like lesion set for long-standing atrial fibrillation concomitant to surgery for valvular or coronary artery disease. Mitral valve surgery alone or combined was performed in 31 cases (75.6%). The mean diameter of the left atrium was 7.19 +/- 1.44 cm. The mean duration of preoperative atrial fibrillation was 4.7 +/- 3.6 years. Patient follow-up was conducted by means of direct clinical examination, electrocardiography, and transthoracic echocardiography. The mean follow-up was 5.37 +/- 0.91 years. RESULTS Patient follow-up was achieved in 82% of cases (n = 28). Seven patients (17%) died during follow-up. Stroke was the cause of death in 1 patient with persistence of atrial fibrillation. Major complications occurred in 4 (14.3%) of the patients that were related to the persistence of atrial fibrillation. At 5 years follow-up, 39.3% of patients (11/28) were in sinus rhythm. Seventeen patients (60.7%) were in New York Heart Association classes I and II, and 11 patients (39.3%) were in New York Heart Association class III at the time of follow-up. CONCLUSION In our experience, left atrial endocardial microwave ablation for long-standing atrial fibrillation after a Cox-Maze-like ablation lesion set during surgery for organic heart disease is not a reliable method of achieving long-term conversion to sinus rhythm.
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Affiliation(s)
- Calin Vicol
- Department of Cardiac Surgery, Grosshadern Medical Center, Ludwig Maximilian University Munich, Munich, Germany.
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Melby SJ, Lee AM, Zierer A, Kaiser SP, Livhits MJ, Boineau JP, Schuessler RB, Damiano RJ. Atrial fibrillation propagates through gaps in ablation lines: implications for ablative treatment of atrial fibrillation. Heart Rhythm 2008; 5:1296-301. [PMID: 18774106 DOI: 10.1016/j.hrthm.2008.06.009] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Accepted: 06/07/2008] [Indexed: 11/29/2022]
Abstract
BACKGROUND It has been hypothesized that atrial lesions must be transmural to successfully cure atrial fibrillation (AF). However, ablation lines often do not extend completely across the atrial wall. OBJECTIVE The purpose of this study was to determine the effect of residual gaps on conduction properties of atrial tissue. METHODS Canine right atria (n = 13) were isolated, perfused, and mounted on a 250-lead electrode plaque. The atria were divided with a bipolar radiofrequency ablation clamp, leaving a gap that was progressively narrowed. Conduction velocities at varying pacing rates and AF frequencies were measured before and after ablations. AF was induced with an extra stimulus and acetylcholine. RESULTS Gap widths from 11.2 to 1.1 mm were examined. Conduction velocities through gaps were dependent cycle length (P = .002) and gap size (P <.001). Overall, 253 (97%) of a total of 260 gaps allowed paced propagation; 51 (91%) of 56 gaps 1-3 mm in width permitted paced propagation, as did 202 (99%) of 204 gaps >or=3.0 mm. Similarly, 253 (97%) of a total of 260 gaps allowed propagation of AF. For AF, 51 (93%) of 55 gaps 1-3 mm allowed AF to pass through, as did 202 (99%) of 205 gaps >or=3.0 mm. Gaps as small as 1.1 mm conducted paced and AF impulses. CONCLUSIONS Conduction velocities were slowed through residual gaps. However, propagation of wave fronts during pacing and AF occurred through the majority of residual gaps, down to sizes as small as 1.1 mm. Leaving viable tissue in ablation lines for the treatment of AF could account for failures.
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Affiliation(s)
- Spencer J Melby
- Department of Surgery, Division of Cardiothoracic Surgery, Washington University in St. Louis School of Medicine and Barnes Jewish Hospital, St. Louis, Missouri 63110, USA
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Histopathological Evaluation of a Novel Radiofrequency Surgical Ablation System. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2008; 3:47-51. [DOI: 10.1097/imi.0b013e31817677a4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Purpose Using a porcine model, this feasibility study was undertaken to evaluate the histopathological characteristics of lesions created in the proximity of the pulmonary veins after ablation with a new endoscopic-guided radiofrequency device. Methods Five adult female swine underwent endoscopic surgical ablation on the epicardial surface of the beating heart. Histologic sections taken from around the pulmonary vein pedicle, representing 10 separate anatomic sites, underwent independent qualitative histopathological evaluation as well as quantitative histomorphometric measurement of lesion depth and section thickness. Results Sections from all five animals had histologically identical lesions, with the majority of ablation foci having pronounced thermal injury characterized by deep and extensive zones of acute myocardial necrosis in the absence of tissue charring. Fifty-seven percent (13 of 23) of the lesions were completely transmural and 91% (21 of 23) of the sections demonstrated ≥70% transmurality. No collateral injuries were noted. Conclusions This irrigated, suction-stabilized unipolar radiofrequency device can produce histologically transmural lesions around the pulmonary veins and is amenable to endoscopic-guided application on the beating heart.
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Saltman AE, Raju NR, Block JE. Histopathological Evaluation of a Novel Radiofrequency Surgical Ablation System. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2008. [DOI: 10.1177/155698450800300201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Adam E. Saltman
- Division of Cardiothoracic Surgery, Maimonides Medical Center, Brooklyn, NY
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Choice of Surgical Lesion Set: Answers From the Data. Ann Thorac Surg 2007; 84:1786-92. [DOI: 10.1016/j.athoracsur.2007.05.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 05/10/2007] [Accepted: 05/14/2007] [Indexed: 11/19/2022]
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Lavee J, Onik G, Mikus P, Rubinsky B. A novel nonthermal energy source for surgical epicardial atrial ablation: irreversible electroporation. Heart Surg Forum 2007; 10:E162-7. [PMID: 17597044 DOI: 10.1532/hsf98.20061202] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND All currently used energy sources in surgical ablation for atrial fibrillation create lesions via thermal injury. We report for the first time the in vivo results of a new nonthermal modality of epicardial atrial ablation called irreversible electroporation (IRE). IRE utilizes a sequence of electrical pulses that produce permanent nonthermal damage to tissue in a few seconds with sharp borders between affected and unaffected regions. METHODS Five pigs underwent beating heart surgical epicardial ablations of their right and/or left atrial appendages, utilizing a sequence of 8, 16, or 32 direct current pulses of 1500 to 2000 V, 100 micros each, at a frequency of 5 per second, applied between two 4-cm long parallel electrodes with an IRE pulse generator. Local temperature measurements were performed during ablations followed by electrical isolation testing by pacing. Animal hearts were excised 24 hours after surgery and processed histologically to evaluate the degree of myocardial tissue necrosis and transmurality. RESULTS A clear demarcation line between ablated and normal tissue, with no tissue disruption or charring, was observed on gross inspection of all lesions. Staining results showed complete transmural destruction of atrial tissue at the site of the electrode application in all 10 atrial lesions, measuring a mean of 0.9 cm in depth. Each 3- to 3.5-cm long lesion was created in 1 to 4 seconds with no local temperature change and with demonstration of electrical isolation. CONCLUSIONS We propose a new modality to perform atrial ablations, which holds the potential of providing very swift, precise, and complete transmurality with no local heating effects.
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Affiliation(s)
- Jacob Lavee
- Department of Cardiothoracic Surgery, Sheba Medical Center, Tel Hashomer, Israel.
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Sagbas E, Akpinar B, Sanisoglu I, Caynak B, Tamtekin B, Oral K, Onan B. Video-Assisted Bilateral Epicardial Pulmonary Vein Isolation for the Treatment of Lone Atrial Fibrillation. Ann Thorac Surg 2007; 83:1724-30. [PMID: 17462389 DOI: 10.1016/j.athoracsur.2006.12.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Revised: 12/06/2006] [Accepted: 12/06/2006] [Indexed: 11/30/2022]
Abstract
BACKGROUND This paper aims to evaluate the feasibility and the efficacy of a new off-pump, bilateral thoracoscopic pulmonary vein isolation technique in patients with lone atrial fibrillation. METHODS Between April 2004 and February 2006, 26 drug-resistant and symptomatic lone atrial fibrillation patients (18 permanent, 8 paroxysmal) underwent an irrigated radiofrequency ablation procedure using the Cardioblate ablation system (Medtronic, Minnesota). There were 16 men and 10 women with a mean age of 55 +/- 11 years. Mean duration of atrial fibrillation was 34.2 +/- 18.9 months. All patients underwent a bilateral thoracoscopic procedure in which both pulmonary veins were ablated with an atrial cuff using an off-pump epicardial approach. The conduction block was assessed by pacing the pulmonary veins after each ablation. Sixteen patients underwent endoscopic stapling of the left atrial appendage. RESULTS There were no hospital deaths. All procedures were completed as planned without any conversions to sternotomy. There were no major complications. Follow-up was complete at 6 months, and 80% of the patients were in sinus rhythm (paroxysmal: 100%, permanent: 72%). Of the patients with permanent atrial fibrillation, 85% had regained their atrial transport function. No major thromboembolic event was observed during the follow-up period. CONCLUSIONS The video-assisted bilateral pulmonary vein isolation technique was safe and effective. It was curative for paroxysmal atrial fibrillation patients and effective for permanent atrial fibrillation cases. This technique may find wider application if accumulating data further support these findings.
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Affiliation(s)
- Ertan Sagbas
- Department of Cardiac Surgery, Florence Nightingale Hospital, Istanbul, Turkey
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Melby SJ, Zierer A, Voeller RK, Lall SC, Bailey MS, Moon MR, Schuessler RB, Damiano RJ. Wide Variations in Energy Delivery Using an Impedance-Controlled Algorithm in Bipolar Radiofrequency Ablation: Evidence against Fixed Time Ablation. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2007. [DOI: 10.1177/155698450700200204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Spencer J. Melby
- Washington University School of Medicine and Barnes-Jewish Hospital, Division of Cardiothoracic Surgery, Department of Surgery, St. Louis, MO
| | - Andreas Zierer
- Washington University School of Medicine and Barnes-Jewish Hospital, Division of Cardiothoracic Surgery, Department of Surgery, St. Louis, MO
| | - Rochus K. Voeller
- Washington University School of Medicine and Barnes-Jewish Hospital, Division of Cardiothoracic Surgery, Department of Surgery, St. Louis, MO
| | - Shelly C. Lall
- Washington University School of Medicine and Barnes-Jewish Hospital, Division of Cardiothoracic Surgery, Department of Surgery, St. Louis, MO
| | - Marci S. Bailey
- Washington University School of Medicine and Barnes-Jewish Hospital, Division of Cardiothoracic Surgery, Department of Surgery, St. Louis, MO
| | - Marc R. Moon
- Washington University School of Medicine and Barnes-Jewish Hospital, Division of Cardiothoracic Surgery, Department of Surgery, St. Louis, MO
| | - Richard B. Schuessler
- Washington University School of Medicine and Barnes-Jewish Hospital, Division of Cardiothoracic Surgery, Department of Surgery, St. Louis, MO
| | - Ralph J. Damiano
- Washington University School of Medicine and Barnes-Jewish Hospital, Division of Cardiothoracic Surgery, Department of Surgery, St. Louis, MO
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Chan JYS, Fung JWH, Yu CM, Feld GK. Preliminary Results with Percutaneous Transcatheter Microwave Ablation of Typical Atrial Flutter. J Cardiovasc Electrophysiol 2007; 18:286-9. [PMID: 17284286 DOI: 10.1111/j.1540-8167.2006.00742.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Linear microwave ablation has been shown to be effective for treatment of atrial fibrillation during open-heart surgery by producing transmural lesions in the atrium to isolate the pulmonary veins. However, the safety and efficacy of percutaneous, transcatheter, linear microwave ablation for atrial arrhythmias, while demonstrated in animal models, is unknown in humans. Therefore, we studied the safety and efficacy of linear microwave ablation of the cavotricuspid isthmus (CTI) in humans with typical atrial flutter, utilizing a 2-cm long microwave antenna mounted on a steerable 9-French catheter. METHODS AND RESULTS In seven consecutive patients, multielectrode catheters were positioned at the His bundle (quadripolar) and around the TV annulus (duo-decapolar) for pacing and recording atrial activation sequence before and after ablation. The microwave antenna was withdrawn gradually from tricuspid annulus towards inferior vena cava to ablate the CTI. Intracardiac ultrasound was used to ensure adequate endocardial contact of the microwave ablation catheter with the CTI. Microwave energy was applied at a power of 18 to 21 W at each ablation point for 120 seconds. Ablation was repeated until bidirectional CTI block was confirmed by demonstrating a descending activation wavefront in the contralateral atrial wall during pacing from the coronary sinus ostium or low lateral right atrium, respectively. Bidirectional isthmus block was achieved in all patients, after a mean number of 27.4 +/- 14.7 energy applications per patients. There were no acute procedural complications. CONCLUSIONS Percutaneous, transcatheter microwave ablation of CTI dependent atrial flutter was demonstrated to be safe and effective in this preliminary feasibility study.
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Affiliation(s)
- Joseph Yat-Sun Chan
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China.
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Gillinov AM, Saltman AE. Ablation of Atrial Fibrillation with Concomitant Cardiac Surgery. Semin Thorac Cardiovasc Surg 2007; 19:25-32. [PMID: 17403454 DOI: 10.1053/j.semtcvs.2007.01.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2007] [Indexed: 11/11/2022]
Abstract
Atrial fibrillation is present in approximately 35% of patients presenting for mitral valve surgery and in 1 to 6% of adult patients undergoing other forms of cardiac surgery. If left untreated, atrial fibrillation is associated with increased morbidity, and, in some subgroups, increased mortality. Therefore, concomitant management of the arrhythmia is indicated in most cardiac surgery patients with preexisting atrial fibrillation. Although the cut-and-sew Cox-maze III procedure is extremely effective, it has been supplanted by newer operations that rely on alternate energy sources to create lines of conduction block. Early and mid-term results are good with a variety of technologies. Choice of lesion set remains a matter of debate, but results of ablation appear to be enhanced by a biatrial lesion set. Targeted areas for improvement in concomitant ablation include acceptance of uniform standards for reporting results, development of improved technology for ablation and intraoperative assessment, and creation of instrumentation that facilitates minimally invasive approaches.
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Affiliation(s)
- A Marc Gillinov
- Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic, Cleveland, Ohio 44195, USA.
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Lall SC, Melby SJ, Voeller RK, Zierer A, Bailey MS, Guthrie TJ, Moon MR, Moazami N, Lawton JS, Damiano RJ. The effect of ablation technology on surgical outcomes after the Cox-maze procedure: A propensity analysis. J Thorac Cardiovasc Surg 2007; 133:389-96. [PMID: 17258570 DOI: 10.1016/j.jtcvs.2006.10.009] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 09/22/2006] [Accepted: 10/09/2006] [Indexed: 11/20/2022]
Abstract
OBJECTIVES Since its introduction in 1987, the Cox-maze procedure has been the gold standard for the surgical treatment of atrial fibrillation. At our institution, this procedure has evolved from the cut-and-sew technique (Cox-maze III procedure) to one using bipolar radiofrequency energy and cryoablation as ablative sources to replace most incisions (Cox-maze IV procedure). This study compared surgical outcomes of patients undergoing the Cox-maze III procedure versus those of patients undergoing the Cox-maze IV procedure by using propensity analysis. METHODS From April 1992 through July 2005, 242 patients underwent the Cox-maze procedure for atrial fibrillation. Of these, 154 patients had the Cox-maze III procedure, and 88 had the Cox-maze IV procedure. Logistic regression analysis was used to identify covariates among 7 baseline patient variables. Using the significant regression coefficients, each patient's propensity score was calculated, allowing selectively matched subgroups of 58 patients each. Operative outcomes were analyzed for differences. Late follow-up was available for 112 (97%) patients. Freedom from atrial fibrillation recurrence and survival was calculated at 1 year by using Kaplan-Meier analysis. RESULTS The Cox-maze III procedure had significantly longer crossclamp times. There was no significant difference in intensive care unit and hospital stay, 30-day mortality, permanent pacemaker placement, early atrial tachyarrhythmias, late stroke, and survival. Freedom from atrial fibrillation recurrence was greater than 90% in both groups at 1 year. CONCLUSIONS The use of bipolar radiofrequency ablation has simplified the Cox-maze procedure, making it applicable to virtually all patients with atrial fibrillation undergoing concomitant cardiac surgery. The Cox-maze IV procedure produces similar surgical outcomes to the Cox-maze III procedure at 1 year of follow-up.
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Affiliation(s)
- Shelly C Lall
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, Saint Louis, Mo 63110, USA
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Melby SJ, Zierer A, Bailey MS, Cox JL, Lawton JS, Munfakh N, Crabtree TD, Moazami N, Huddleston CB, Moon MR, Damiano RJ. A new era in the surgical treatment of atrial fibrillation: the impact of ablation technology and lesion set on procedural efficacy. Ann Surg 2006; 244:583-92. [PMID: 16998367 PMCID: PMC1856555 DOI: 10.1097/01.sla.0000237654.00841.26] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND/OBJECTIVE While the Cox-Maze procedure remains the gold standard for the surgical treatment of atrial fibrillation (AF), the use of ablation technology has revolutionized the field. To simplify the procedure, our group has replaced most of the incisions with bipolar radiofrequency ablation lines. The purpose of this study was to examine results using bipolar radiofrequency in 130 patients undergoing a full Cox-Maze procedure, a limited Cox-Maze procedure, or pulmonary vein isolation alone. METHODS A retrospective review was performed of patients who underwent a Cox-Maze procedure (n = 100), utilizing bipolar radiofrequency ablation, a limited Cox-Maze procedure (n = 7), or pulmonary vein isolation alone (n = 23). Follow-up was available on 129 of 130 patients (99%). RESULTS Pulmonary vein isolation was confirmed by intraoperative pacing in all patients. Cross-clamp time in the lone Cox-Maze procedure patients was 44 +/- 21 minutes, and 104 +/- 42 minutes for the Cox-Maze procedure with a concomitant procedure, which was shortened considerably from our traditional cut-and-sew Cox-Maze procedure times (P < 0.05). There were 4 postoperative deaths in the Cox-Maze procedure group and 1 in the pulmonary vein isolation group. The mean follow-up was 13 +/- 10, 23 +/- 15, and 9 +/- 10 months for the Cox-Maze IV, the pulmonary vein isolation, and the limited Cox-Maze procedure groups, respectively. At last follow-up, freedom from AF was 90% (85 of 94), 86% (6 of 7), and 59% (10 of 17) in the in the Cox-Maze procedure group, limited Cox-Maze procedure group, and pulmonary vein isolation alone group, respectively. CONCLUSIONS The use of bipolar radiofrequency ablation to replace Cox-Maze incisions was safe and effective at controlling AF. Pulmonary vein isolation alone was much less effective, and should be used cautiously in this population.
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Affiliation(s)
- Spencer J Melby
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine and Barnes-Jewish Hospital, St Louis, MO 63110, USA
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Damiano RJ, Voeller RK. Surgical and minimally invasive ablation for atrial fibrillation. CURRENT TREATMENT OPTIONS IN CARDIOVASCULAR MEDICINE 2006; 8:371-6. [PMID: 16939675 DOI: 10.1007/s11936-006-0041-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The Cox-Maze procedure, first introduced in 1987, has been the gold standard for the surgical treatment of atrial fibrillation. At 10 years, over 90% of patients remain free from atrial fibrillation. The procedure has been shown to be effective at eliminating the incidence of late stroke in this high-risk population. The development of new ablation technologies has greatly simplified and shortened the Cox-Maze procedure without sacrificing efficacy. These technologies have spurred interest in the development of new, simpler operations for the surgical treatment of atrial fibrillation that can be performed through minimal access and, in some instances, off of cardiopulmonary bypass. The early results with these more limited procedures on the whole have not been as good as with the Cox-Maze procedure, but they are promising. There are many problems with the development of a truly minimally invasive procedure with high efficacy. When patients are referred for surgery, there is no information available regarding the mechanisms of their atrial fibrillation. Thus, it is impossible to tailor the ablation to the individual patient. Future progress will require better understanding of the mechanisms of atrial fibrillation, and the development and refinement of clinical diagnostic technology that will allow for better preoperative diagnosis.
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Affiliation(s)
- Ralph J Damiano
- Cardiothoracic Surgery, Washington University School of Medicine, Campus Box 8234, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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Melby SJ, Zierer A, Kaiser SP, Schuessler RB, Damiano RJ. Epicardial microwave ablation on the beating heart for atrial fibrillation: The dependency of lesion depth on cardiac output. J Thorac Cardiovasc Surg 2006; 132:355-60. [PMID: 16872962 DOI: 10.1016/j.jtcvs.2006.02.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Revised: 01/24/2006] [Accepted: 02/06/2006] [Indexed: 11/29/2022]
Abstract
BACKGROUND Microwave energy is commonly used on the beating heart to create lesions for the surgical treatment of atrial fibrillation. However, lesion transmurality is likely to depend on several factors including tissue thickness and blood flow. This study was designed to determine the effect of cavitary blood flow on transmurality of acute atrial lesions with the FLEX 10 (Guidant Corporation, Santa Clara, Calif) microwave device. METHODS Six pigs underwent median sternotomy and were placed on cardiopulmonary bypass. Microwave lesions on the atrium were performed for 60 seconds at 65 Watts at 4 different levels of cardiac output by varying cardiopulmonary bypass flow rates. Cardiac output was measured with a pulmonary artery flow probe. Four additional lesions on 2 animals were done for 120 seconds at 65 Watts with 0.0 to 0.5 L/min cardiac output. The animals were sacrificed, and tissue was stained with 2,3,5-triphenyltetrazolium chloride and sectioned at 5-mm intervals. Lesion depth and width were determined from photomicrographs. RESULTS Sixty-second lesions were transmural in 90%, 65%, 54%, and 46% of atrial sections at cardiac output of 0.0 to 0.5 L/min, 0.6 to 1.9 L/min, 2.0 to 3.9 L/min, and 4.0 L/min or greater, respectively (P < .001). When ablations were performed for 120 seconds with a cardiac output of 0.0 to 0.5 L/min, 100% of lesions were transmural. Lesion width was also related to cardiac output, with the widest lesions produced when cardiac output was 0.0 to 0.5 L/min. CONCLUSIONS Acute microwave ablation lesion depth and width are strongly dependent on the magnitude of cardiac output. Transmural lesions can be reliably produced on the porcine heart only while on cardiopulmonary bypass.
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Affiliation(s)
- Spencer J Melby
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, Mo 63110, USA
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Smedira NG, Gillinov AM. Invited commentary. Ann Thorac Surg 2005; 81:76-7. [PMID: 16368339 DOI: 10.1016/j.athoracsur.2005.08.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2005] [Revised: 08/17/2005] [Accepted: 08/24/2005] [Indexed: 10/25/2022]
Affiliation(s)
- Nicholas G Smedira
- Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
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