Cirugía de las taquiarritmias. Puesta al día

Podeu consultar la versió publicada al Diari Oficial de la Generalitat de Catalunya a: http://hdl.handle.net/11703/8674

Tratamiento quirúrgico de la fibrilación auricular. ¿Dónde estamos?

La cirugía de la fibrilación auricular ha presentado un gran avance en la última década, siendo actualmente habitual su tratamiento quirúrgico. Ha destacado la ablación intraoperatoria mediante nuevas formas de energía y dispositivos quirúrgicos, con la finalidad de facilitar lesiones térmicas transmurales a modo de atriotomías. Sin embargo, existen aspectos por aclarar, como la efectividad a largo plazo de los procedimientos, índices de tromboembolia, contracción auricular posquirúrgica, recurrencias de la arritmia, morbimortalidad del procedimiento, patrones de lesiones y fuentes de energía.Surgery of the atrial fibrillation has greatly advanced in the last decade, being nowadays common its surgical treatment. Intraoperative ablation with new forms of energy and surgical devices, to facilitate transmural thermal injuries like atriotomies have been an important part of the progress. Nevertheless, there are a number of issues that need clarification like the long-term efficiency of the procedures, the incidence of stroke, postsurgical atrial contraction, recurrence of the arrhythmia, morbi-mortality of the procedure, pattern of lesions and sources of energy

A cooled intraesophageal balloon to prevent thermal injury during endocardial surgical radiofrequency ablation of the left atrium: a finite element study

[EN] Recent clinical studies on intraoperative monopolar radiofrequency ablation of atrial fibrillation have reported some cases of injury to the esophagus. The aim of this study was to perform computer simulations using three-dimensional finite element models in order to investigate the feasibility of a cooled intraesophageal balloon appropriately placed to prevent injury. The models included atrial tissue and a fragment of esophagus and lung linked by connective tissue. The lesion depth in the esophagus was assessed using a 50 degrees C isotherm and expressed as a percentage of thickness of the esophageal wall. The results are as follows: (1) chilling the esophagus by means of a cooled balloon placed in the lumen minimizes the lesion in the esophageal wall compared to the cases in which no balloon is used (a collapsed esophagus) and with a non-cooled balloon; (2) the temperature of the cooling fluid has a more significant effect on the minimization of the lesion than the rate of cooling (the thermal transfer coefficient for forced convection); and (3) pre-cooling periods previous to RF ablation do not represent a significant improvement. Finally, the results also suggest that the use of a cooled balloon could affect the transmurality of the atrial lesion, especially in the cases where the atrium is of considerable thickness.The authors wish to thank Mr Trevor Lepp for the manuscript corrections, and the reviewers for their comments. This work was partially supported by a grant from the Spanish Ministry of Education and Science (Project CAMAEC-III) and by Programa de Incentivo a la Investigación (Universidad Politécnica de Valencia, Spain).Berjano, E.; Hornero, F. (2015). A cooled intraesophageal balloon to prevent thermal injury during endocardial surgical radiofrequency ablation of the left atrium: a finite element study. Physics in Medicine and Biology. 50(20):269-279. https://doi.org/10.1088/0031-9155/50/20/N03S2692795020Al-Zaben, A., & Chandrasekar, V. (2005). Effect of esophagus status and catheter configuration on multiple intraluminal impedance measurements. Physiological Measurement, 26(3), 229-238. doi:10.1088/0967-3334/26/3/008Bhattacharya, A., & Mahajan, R. L. (2003). Temperature dependence of thermal conductivity of biological tissues. Physiological Measurement, 24(3), 769-783. doi:10.1088/0967-3334/24/3/312Benussi, S., Nascimbene, S., Agricola, E., Calori, G., Calvi, S., Caldarola, A., … Alfieri, O. (2002). Surgical ablation of atrial fibrillation using the epicardial radiofrequency approach: mid-term results and risk analysis. The Annals of Thoracic Surgery, 74(4), 1050-1057. doi:10.1016/s0003-4975(02)03850-xBerjano, E. J., & Hornero, F. (2004). Thermal-Electrical Modeling for Epicardial Atrial Radiofrequency Ablation. IEEE Transactions on Biomedical Engineering, 51(8), 1348-1357. doi:10.1109/tbme.2004.827545Berjano, E. J., & Hornero, F. (2005). What affects esophageal injury during radiofrequency ablation of the left atrium? An engineering study based on finite-element analysis. Physiological Measurement, 26(5), 837-848. doi:10.1088/0967-3334/26/5/020Chang, I. A., & Nguyen, U. D. (2004). Thermal modeling of lesion growth with radiofrequency ablation devices. BioMedical Engineering OnLine, 3(1). doi:10.1186/1475-925x-3-27Chiappini, B., Martìn-Suàrez, S., LoForte, A., Di Bartolomeo, R., & Marinelli, G. (2003). Surgery for atrial fibrillation using radiofrequency catheter ablation. The Journal of Thoracic and Cardiovascular Surgery, 126(6), 1788-1791. doi:10.1016/s0022-5223(03)01045-6Doll, N., Borger, M. A., Fabricius, A., Stephan, S., Gummert, J., Mohr, F. W., … Hindricks, G. (2003). Esophageal perforation during left atrial radiofrequency ablation: Is the risk too high? The Journal of Thoracic and Cardiovascular Surgery, 125(4), 836-842. doi:10.1067/mtc.2003.165Gabriel, C., Gabriel, S., & Corthout, E. (1996). The dielectric properties of biological tissues: I. Literature survey. Physics in Medicine and Biology, 41(11), 2231-2249. doi:10.1088/0031-9155/41/11/001Gaynor, S. L., Diodato, M. D., Prasad, S. M., Ishii, Y., Schuessler, R. B., Bailey, M. S., … Damiano, R. J. (2004). A prospective, single-center clinical trial of a modified Cox maze procedure with bipolar radiofrequency ablation. The Journal of Thoracic and Cardiovascular Surgery, 128(4), 535-542. doi:10.1016/j.jtcvs.2004.02.044Gillinov, A. M., Pettersson, G., & Rice, T. W. (2001). Esophageal injury during radiofrequency ablation for atrial fibrillation. The Journal of Thoracic and Cardiovascular Surgery, 122(6), 1239-1240. doi:10.1067/mtc.2001.118041Haemmerich, D., Webster, J. G., & Mahvi, D. M. (s. f.). Thermal dose versus isotherm as lesion boundary estimator for cardiac and hepatic radio-frequency ablation. Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439). doi:10.1109/iembs.2003.1279532YEN HO, S., SANCHEZ-QUINTANA, D., CABRERA, J. A., & ANDERSON, R. H. (1999). Anatomy of the Left Atrium:. Journal of Cardiovascular Electrophysiology, 10(11), 1525-1533. doi:10.1111/j.1540-8167.1999.tb00211.xHornero, F., Rodriguez, I., Bueno, M., Buendia, J., Dalmau, M. J., Canovas, S., … Montero, J. A. (2004). Surgical Ablation of Permanent Atrial Fibrillation by Means of Maze Radiofrequency:. Mid-Term Results. Journal of Cardiac Surgery, 19(5), 383-388. doi:10.1111/j.0886-0440.2004.04077.xJain, M. K., & Wolf, P. D. (1999). Temperature-controlled and constant-power radio-frequency ablation: what affects lesion growth? IEEE Transactions on Biomedical Engineering, 46(12), 1405-1412. doi:10.1109/10.804568Lemola, K., Sneider, M., Desjardins, B., Case, I., Han, J., Good, E., … Oral, H. (2004). Computed Tomographic Analysis of the Anatomy of the Left Atrium and the Esophagus. Circulation, 110(24), 3655-3660. doi:10.1161/01.cir.0000149714.31471.fdNath, S., Lynch, C., Whayne, J. G., & Haines, D. E. (1993). Cellular electrophysiological effects of hyperthermia on isolated guinea pig papillary muscle. Implications for catheter ablation. Circulation, 88(4), 1826-1831. doi:10.1161/01.cir.88.4.1826Pappone, C., Oral, H., Santinelli, V., Vicedomini, G., Lang, C. C., Manguso, F., … Morady, F. (2004). Atrio-Esophageal Fistula as a Complication of Percutaneous Transcatheter Ablation of Atrial Fibrillation. Circulation, 109(22), 2724-2726. doi:10.1161/01.cir.0000131866.44650.46Sonmez, B., Demirsoy, E., Yagan, N., Unal, M., Arbatli, H., Sener, D., … Ilkova, F. (2003). A fatal complication due to radiofrequency ablation for atrial fibrillation: atrio-esophageal fistula. The Annals of Thoracic Surgery, 76(1), 281-283. doi:10.1016/s0003-4975(03)00006-

Impedance measurement to assess epicardial fat prior to RF intraoperative cardiac ablation: a feasibility study using a computer model

[EN] Radiofrequency (RF) cardiac ablation is used to treat certain types of arrhythmias. In the epicardial approach, efficacy of RF ablation is uncertain due to the presence of epicardial adipose tissue interposed between the ablation electrode and the atrial wall. We planned a feasibility study based on a theoretical model in order to assess a new technique to estimate the quantity of fat by conducting bioimpedance measurements using a multi-electrode probe. The finite element method was used to solve the electrical problem. The results showed that the measured impedance profile coincided approximately with the epicardial fat profile measured under the probe electrodes and also that the thicker the epicardial fat, the higher the impedance values. When the lateral fat width was less than 4.5 mm, the impedance values altered, suggesting that measurements should always be conducted over a sizeable fat layer. We concluded that impedance measurement could be a practical method of assessing epicardial fat prior to RF intraoperative cardiac ablation, i.e. 'to map' the amount of adipose tissue under the probe.This work was supported by a research grant from the Spanish Government in the 'Plan Nacional de I+D+I del Ministerio de Ciencia e Innovacion' (TEC2008-01369/TEC). The English revision and correction of this note was funded by the Universidad Politecnica de Valencia, Spain.González-Suárez, A.; Hornero, F.; Berjano, E. (2010). Impedance measurement to assess epicardial fat prior to RF intraoperative cardiac ablation: a feasibility study using a computer model. Physiological Measurement. 31(11):95-104. https://doi.org/10.1088/0967-3334/31/11/N03S951043111Ba, M., Fornés, P., Nutu, O., Latrémouille, C., Carpentier, A., & Chachques, J. C. (2008). Treatment of atrial fibrillation by surgical epicardial ablation: Bipolar radiofrequency versus cryoablation. Archives of Cardiovascular Diseases, 101(11-12), 763-768. doi:10.1016/j.acvd.2008.07.004Benjamin, E. J. (1994). Independent risk factors for atrial fibrillation in a population-based cohort. The Framingham Heart Study. JAMA: The Journal of the American Medical Association, 271(11), 840-844. doi:10.1001/jama.271.11.840Berjano, E. J., & Hornero, F. (2004). Thermal-Electrical Modeling for Epicardial Atrial Radiofrequency Ablation. IEEE Transactions on Biomedical Engineering, 51(8), 1348-1357. doi:10.1109/tbme.2004.827545Berjano, E. J., & Hornero, F. (2005). A cooled intraesophageal balloon to prevent thermal injury during endocardial surgical radiofrequency ablation of the left atrium: a finite element study. Physics in Medicine and Biology, 50(20), N269-N279. doi:10.1088/0031-9155/50/20/n03HORNERO, F., & BERJANO, E. J. (2006). Esophageal Temperature During Radiofrequency-Catheter Ablation of Left Atrium: A Three-Dimensional Computer Modeling Study. Journal of Cardiovascular Electrophysiology, 17(4), 405-410. doi:10.1111/j.1540-8167.2006.00404.xCox, J. L., Schuessler, R. B., Lappas, D. G., & Boineau, J. P. (1996). An 8½-Year Clinical Experience with Surgery for Atrial Fibrillation. Annals of Surgery, 224(3), 267-275. doi:10.1097/00000658-199609000-00003Deneke, T., Khargi, K., Müller, K.-M., Lemke, B., Mügge, A., Laczkovics, A., … Grewe, P. H. (2005). Histopathology of intraoperatively induced linear radiofrequency ablation lesions in patients with chronic atrial fibrillation. European Heart Journal, 26(17), 1797-1803. doi:10.1093/eurheartj/ehi255Doss, J. D. (1982). Calculation of electric fields in conductive media. Medical Physics, 9(4), 566-573. doi:10.1118/1.595107Dumas III, J. H., Himel IV, H. D., Kiser, A. C., Quint, S. R., & Knisley, S. B. (2008). Myocardial electrical impedance as a predictor of the quality of RF-induced linear lesions. Physiological Measurement, 29(10), 1195-1207. doi:10.1088/0967-3334/29/10/004Gabriel, S., Lau, R. W., & Gabriel, C. (1996). The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues. Physics in Medicine and Biology, 41(11), 2271-2293. doi:10.1088/0031-9155/41/11/003Suárez, A. G., Hornero, F., & Berjano, E. J. (2010). Mathematical Modeling of Epicardial RF Ablation of Atrial Tissue with Overlying Epicardial Fat. The Open Biomedical Engineering Journal, 4(1), 47-55. doi:10.2174/1874120701004020047Hong, K. N., Russo, M. J., Liberman, E. A., Trzebucki, A., Oz, M. C., Argenziano, M., & Williams, M. R. (2007). Effect of Epicardial Fat on Ablation Performance: A Three-Energy Source Comparison. Journal of Cardiac Surgery, 22(6), 521-524. doi:10.1111/j.1540-8191.2007.00454.xKannel, W. ., Wolf, P. ., Benjamin, E. ., & Levy, D. (1998). Prevalence, incidence, prognosis, and predisposing conditions for atrial fibrillation: population-based estimates 11Reprints are not available. The American Journal of Cardiology, 82(7), 2N-9N. doi:10.1016/s0002-9149(98)00583-9Khargi, K., Hutten, B. A., Lemke, B., & Deneke, T. (2005). Surgical treatment of atrial fibrillation; a systematic review☆. European Journal of Cardio-Thoracic Surgery, 27(2), 258-265. doi:10.1016/j.ejcts.2004.11.003Mitnovetski, S., Almeida, A. A., Goldstein, J., Pick, A. W., & Smith, J. A. (2009). Epicardial High-intensity Focused Ultrasound Cardiac Ablation for Surgical Treatment of Atrial Fibrillation. Heart, Lung and Circulation, 18(1), 28-31. doi:10.1016/j.hlc.2008.08.003Miyagi, Y., Ishii, Y., Nitta, T., Ochi, M., & Shimizu, K. (2009). Electrophysiological and Histological Assessment of Transmurality after Epicardial Ablation Using Unipolar Radiofrequency Energy. Journal of Cardiac Surgery, 24(1), 34-40. doi:10.1111/j.1540-8191.2008.00747.xPruitt, J. C., Lazzara, R. R., & Ebra, G. (2007). Minimally invasive surgical ablation of atrial fibrillation: The thoracoscopic box lesion approach. Journal of Interventional Cardiac Electrophysiology, 20(3), 83-87. doi:10.1007/s10840-007-9172-3Santiago, T., Melo, J., Gouveia, R. H., Neves, J., Abecasis, M., Adragão, P., & Martins, A. P. (2003). Epicardial radiofrequency applications: in vitro and in vivo studies on human atrial myocardium☆. European Journal of Cardio-Thoracic Surgery, 24(4), 481-486. doi:10.1016/s1010-7940(03)00344-0Santiago, T., Melo, J. oã. Q., Gouveia, R. H., & Martins, A. P. (2003). Intra-atrial temperatures in radiofrequency endocardial ablation: histologic evaluation of lesions. The Annals of Thoracic Surgery, 75(5), 1495-1501. doi:10.1016/s0003-4975(02)04990-1Wolf, P. A., Abbott, R. D., & Kannel, W. B. (1991). Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke, 22(8), 983-988. doi:10.1161/01.str.22.8.98

Reliability assessment of a cooled intraesophageal balloon to prevent thermal injury during RF cardiac ablation: an agar phantom study

[EN] Cooled Balloon Prevents Thermal Injury During RF Ablation. Introduction: The use of a cooled intraesophageal balloon has recently been proposed to minimize the risk of thermal injury in the esophagus during radiofrequency (RF) ablation of the left atrium. However, the capacity of this device to adequately protect the esophagus under different procedural and anatomical conditions remains unknown. Methods and Results: An agar phantom-based model was built that provided temperature readings not only on the cooled balloon (T-b) but also at a hypothetical point between the esophageal lumen and myocardium at a distance of 2 mm (T2-mm). The RF ablations were conducted considering two anatomical factors (total distance between the electrode and balloon and flow rate around the electrode) and two procedural factors (angle and pressure between the electrode and agar surface). The results show that most of the parameters studied have no significant influence on the temperature measured on the cooled balloon (T-b), the exception being a variation in the flow rate, which was found to influence the temperature. On the other hand, T2-mm was affected to a great extent by all the factors considered, the smallest influence being that of the contact pressure. The results also suggest that when an intraesophageal balloon is employed, the applied power is not a good predictor either of the temperature on the balloon or of the temperature measured at a distance 2 mm away. Conclusion: The results suggest that a cooled intraesophageal balloon provides effective thermal protection of the esophageal lumen. However, under certain circumstances, the temperature reached at a distance 2 mm away could possibly put at risk the integrity of the inner layers of the esophagus. (J Cardiovasc Electrophysiol, Vol. 19, pp. 1188-1193, November 2008).This work was partially supported by the "Plan Nacional de Investigacion Cientifica, Desarrollo e Innovaci on Tecnologica del Ministerio de Educacion y Cienciaa of Spain (TEC 2005-04199/TCM) and by an R&D contract (CSIC-20060633) between Edwards Lifescience Ltd. and the Spanish Council for Scientific Research (CSIC).Lequerica, JL.; Berjano, E.; Herrero, M.; Hornero, F. (2008). Reliability assessment of a cooled intraesophageal balloon to prevent thermal injury during RF cardiac ablation: an agar phantom study. Journal of Cardiovascular Electrophysiology. 19(11):1188-1193. https://doi.org/10.1111/j.1540-8167.2008.01229.xS11881193191

Efecto de la frecuencia del ritmo sinusal en la generación de reentradas en un modelo 3D de aurícula humana remodelada

Las arritmias auriculares son las taquiarritmias más comunes en humanos. Recientemente, se ha demostrado que una actividad ectópica alrededor de las venas pulmonares puede generar mecanismos reentrantes en presencia de un sustrato vulnerable. En este estudio, examinamos el efecto de la frecuencia del ritmo sinusal para contribuir en la generación de mecanismos reentrantes iniciados por actividad ectópica. Los efectos del remodelado en las corrientes iónicas se incorporaron en un modelo 3D de aurícula humana, altamente realista. Sólo a altas frecuencias del ritmo sinusal (longitud del ciclo base ≤ 300 ms), la actividad ectópica provocó la generación de reentradas en figura de ocho en la aurícula derecha. Nuestro estudio sugiere que la interacción de actividad ectópica con un ritmo sinusal a alta frecuencia facilita la generación de mecanismos reentrantes en aurícula humana remodelada