eISSN: 1897-4252
ISSN: 1731-5530
Kardiochirurgia i Torakochirurgia Polska/Polish Journal of Thoracic and Cardiovascular Surgery
Current issue Archive About the journal Supplements Editorial board Abstracting and indexing Contact Instructions for authors Ethical standards and procedures
SCImago Journal & Country Rank

 
1/2020
vol. 17
 
Share:
Share:
more
 
 
Original paper

The influence of epicardial and endocardial use of cryoenergy on the completeness of lesions in surgical ablation of atrial fibrillation

Vojtech Kurfirst
1
,
Julia Csanady
1
,
Ales Mokracek
1
,
Jiri Hanis
1
,
Alan Bulava
1
,
Ladislav Pesl
1

1.
Department of Cardiac and Thoracic Surgery, Hospital of České Budějovice, České Budějovice, Czech Republic
Kardiochir Torakochir Pol 2020; 17 (1): 29-32
Online publish date: 2020/04/07
Article file
Get citation
ENW
EndNote
BIB
JabRef, Mendeley
RIS
Papers, Reference Manager, RefWorks, Zotero
AMA
APA
Chicago
Harvard
MLA
Vancouver
 
 

Introduction

The Cox MAZE IV is the gold standard for surgical treatment of atrial fibrillation (AF) [1, 2]. However, since its introduction, many variations in the number and location of individual lesions and in the form of supplied energy have been described [3]. Cryoenergy, along with radio-frequency energy, is the most commonly used method of lesion formation in patients after surgical ablation of atrial fibrillation, with good and stable long-term results [4–6]. Despite frequent use, the clinical effect of cryoenergy in the endocardial and epicardial approaches is not sufficiently known. For these reasons, surgeons sometimes refuse to simultaneously add surgical ablation of AF to the main surgery. In clinical practice, many patients attending cardiac surgery with AF are not treated at all (up to 50%) [7].

Aim

The aim of this study was to compare the clinical effect of various cryoenergy applications on the postoperative incidence of sinus rhythm and the completeness of lesions performed.

Material and methods

This was a single-centre, prospective study. A total of 55 patients underwent surgical ablation of AF as part of another cardiac surgery procedure (myocardial revascularisation, valve surgery, combined procedure). Before the start of the study the authors obtained approval from the institutional Ethical Committee regarding the study design. The selection criteria were: AF refractory to at least one class I or class III antiarrhythmic therapy, concomitant cardiac surgery, absence of prior catheter ablation, and written, informed consent to study participation and postoperative electrophysiological examination. The standard surgical ablation protocol includes the isolation of the pulmonary veins and the formation of a box lesion by cryoenergy under various conditions – epicardially on extracorporeal circulation and cardiac arrest, epicardial on extracorporeal circulation on the beating heart, and endocardial. A Cardioblate® CryoFlex® surgical ablation probe, Medtronic, Minneapolis, USA was used to create the lesion. The standard duration of cryoenergy application was 2 minutes at –160°C. The electrical insulation of the lesions was not electrically verified during the operation. All of the patients underwent left atrial appendage occlusion using an Atriclip device. In the postoperative period, treatment of AF was as follows: all patients were on anticoagulant therapy with warfarin for 3 months. If they had AF during the postoperative period, they were pharmacologically treated with Cordarone or electroconversion, and patients were given oral Cordarone for 1 month after surgery. During the postoperative period, patients were invited to attend an electrophysiological examination to assess the completeness of surgical ablation lesions and, if necessary, to supplement the lesions with catheter ablation.
All catheterisation procedures were performed using the CARTO3 mapping system. None of the patients was on anti-arrhythmic therapy during electrophysiological examination. If a normal sinus rhythm was present at the beginning of the procedure, RF ablation of the cavotricuspid isthmus was performed prior to initiation of left atrial ablation. The achievement of a bidirectional block of conduction through the isthmus was determined by standard criteria. Then, after double trans-septal punctures, two controllable trans-septal sheaths (8F, Channel, BARD Electrophysiology, Lowell, MA, USA) were introduced into the left atrium (LA), and a virtual anatomy reconstruction was performed, and a bipolar voltage map obtained at least 300 points for detailed mapping of the whole LA. A circular mapping catheter (LASSO®, Biosense Webster, Inc., Diamond Bar, CA, USA) was used in all veins to confirm isolation or electrical reconnection. RF energy was applied using a ThermoCool® Smart Touch™ catheter with a 3.5 mm irrigated tip (Biosense Webster, Inc.) and a software module that allows contact force sensing with a temperature limitation of 44°C and radio-frequency energy of up to 35 W. After reaching the insulation of all the veins (if they were reconnected), the posterior wall of the LA was mapped to confirm electrical insulation. For this purpose, the Lasso catheter was positioned so as to be perpendicular to the posterior wall. If no potentials were noted, the box lesion was considered present. If any potential was noted, both superior and inferior connecting lines were mapped to look for a gap. All gaps were subsequently ablated. Data were collected from the hospital medical electronic system and during postoperative controls by patients’ surgeons.

Statistical analysis

Data are presented as mean ± SD for continuous variables and percentages or numbers for categoric variables. Baseline clinical characteristics of patients were calculated.

Results

Twenty-four patients underwent epicardial ablation on the arrested heart (group 1), 12 patients underwent epicardial ablation on the beating heart (group 2), and 19 patients underwent endocardial ablation (group 3), as shown in Table I. The interval between cardiac surgery and electrophysiological examination was 144 ±138 days (group 1) vs. 178 ±84 days (group 2) vs. 102 ±76 days (group 3). During electrophysiological examination (Table II), sinus rhythm was present in 71% of patients 83% vs. 89% of patients in the groups 1, 2 and 3 (Figure 1). The completeness of pulmonary vein isolation was confirmed in 31% vs. 25% vs. 95% of patients and complete box lesion in 15% vs. 0% vs. 79% of patients, in the groups 1, 2 and 3 respectively (Figure 2).

Discussion

In the past, several articles were published dealing with the use of cryoenergy from the epicardial and endocardial approaches [6–16]. However, these studies were performed under laboratory conditions in an animal model, and the results were evaluated histologically in the acute phase of healing. Our work brings results from clinical practice, in which the structure of the left atrial wall is influenced by ongoing AF and the results of surgical ablation are evaluated electrophysiologically and along the entire length of the ablation line. There is also some time to create the scar after surgical ablation. This is one of the most accurate ways to evaluate the success of surgical ablation. According to available US registries, cryoenergy is used in approximately 30–50% of patients undergoing concomitant surgical ablation primarily from the epicardial approach [17].
Use of cryoenergy from the endocardial approach is an established method that encounters several obstacles: in patients without mitral and tricuspid valve defects, bicaval cannulation and opening on the left and right atria is necessary. This results in prolonged cardiac arrest interval, and a risk of air embolisation and postoperative bleeding. For these reasons, surgeons sometimes refuse to simultaneously add surgical ablation of AF to the main control. In clinical practice, many patients attending cardiac surgery with AF are not treated at all – up to 50% [17].
Our work also shows that the clinical effect of surgical ablation in terms of maintaining sinus rhythm in the postoperative period may not be identified with the completeness of surgical lesions. The incompleteness of surgical lesions may lead to a lower incidence of sinus rhythm in the postoperative period, and individual gaps in surgical lesions may have more proarrhythmogenic potential [18–20].
The limitations of this study are particularly evident in a small number of patients. However, our results may indicate a direction for further research into the surgical use of cryoenergy.

Conclusions

Despite the similar clinical effect of surgical ablation in all three approaches, the most electrophysiologically effective use of cryoenergy is endocardial ablation. This approach has a very good result. Our finding further supports the endocardial use of cryoenergy during surgical ablation of atrial fibrillation, and the results of this local study have led to changes in our workplace practices.

Disclosure

The authors report no conflict of interest.

References

1. Weimar T, Bailey MS, Watanabe Y, Marin D, Maniar HS, Schuessler RB, Damiano RJ Jr. The Cox-maze IV procedure for lone atrial fibrillation: a single center experience in 100 consecutive patients. J Interv Card Electrophysiol 2011; 31: 47-54.
2. Damiano Jr RJ, Schwartz FH, Bailey MS, Maniar HS, Munfakh NA, Moon MR, Schuessler RB. The Cox maze IV procedure: predictors of late recurrence. J Thorac Cardiovasc Surgery 2011; 141: 113-121.
3. Kirchhof P, Benussi S, Kotecha D, Ahlsson A, Atar D, Casadei B, Castella M, Diener HC, Heidbuchel H, Hendriks J, Hindricks G, Manolis AS, Oldgren J, Popescu BA, Schotten U, Van Putte B, Vardas P. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS: The Task Force for the management of atrial fibrillation of the European Society of Cardiology (ESC). Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Endorsed by the European Stroke Organisation (ESO). Eur Heart J 2016; 37: 2893-2962.
4. Kim JB, Cho WC, Jung SH, Chung CH, Choo SJ, Lee JW. Alternative energy sources for surgical treatment of atrial fibrillation in patients undergoing mitral valve surgery: microwave ablation vs cryoablation. J Korean Med Sci 2010; 25: 1467-1472.
5. Gaynor SL, Diodato MD, Prasad SM, Ishii Y, Schuessler RB, Bailey MS, Damiano NR, Bloch JB, Moon MR, Damiano RJ Jr. A prospective, single-center clinical trial of a modified Cox maze procedure with bipolar radiofrequency ablation. J Thorac Cardiovasc Surg 2004; 128: 535-542.
6. Hong KN, Russo MJ, Liberman EA, Trzebucki A, Oz MC, Argenziano M, Williams MR. Effect of epicardial fat on ablation performance: a three-energy source comparison. J Card Surg 2007; 22: 521-524.
7. Suwalski P, Kowalewski M, Jasinski M, Staromłyński J, Zembala M, Widenka K, Brykczyński M, Skiba J, Zembala MO, Bartuś K, Hirnle T, Dziembowska I, Deja M, Tobota Z, Maruszewski BJ. Surgical ablation for atrial fibrillation during isolated coronary artery bypass surgery. Eur J Cardiothorac Surg 2020; 57: 691-700.
8. Doll N, Kornherr P, Aupperle H, Fabricius AM, Kiaii B, Ullmann C, Schneider K, Dhein S, Schoon HA, Rastan A, Walther T, Mohr FW. Epicardial treatment of atrial fibrillation using cryoablation in an acute off-pump sheep model. Thorac Cardiovasc Surg 2003; 51: 267-273.
9. Manasse E, Colombo P, Roncalli M, Gallotti R. Myocardial acute and chronic histological modifications induced by cryoablation. Eur J Cardiothorac Surg 2000; 17: 339-340.
10. Hunt GB, Chard RB, Johnson DC, Ross DL. Comparison of early and late dimensions and arrhythmogenicity of cryolesions in the normothermic canine heart. J Thorac Cardiovasc Surg 1989; 97: 313-318.
11. Guiraudon GM, Jones DL, Skanes AC, Bainbridge D, Guiraudon CM, Jensen SM, Yuan X, Drangova M, Peters TM. En bloc exclusion of the pulmonary vein region in the pig using off pump, beating, intra-cardiac surgery: a pilot study of minimally invasive surgery for atrial fibrillation. Ann Thorac Surg 2005; 80: 1417-1423.
12. Milla F, Skubas N, Briggs WM, Girardi LN, Lee LY, Ko W, Tortolani AJ, Krieger KH, Isom W, Mack CA. Epicardial beating heart cryoablation using a novel argonbased cryoclamp and linear probe. J Thorac Cardiovasc Surg 2006; 131: 403-411.
13. Mack CA, Milla F, Ko W, Girardi LN, Lee LY, Tortolani AJ, Mascitelli J, Krie-ger KH, Isom OW. Surgical treatment of atrial fibrillation using argon-based cryoablation during concomitant cardiac procedures. Circulation 2005; 112 (9 Suppl): I1-I6.
14. Doll N, Kiaii BB, Fabricius AM, Bucerius J, Kornherr P, Krakor R, Gummert JF, Walther T, Mohr FW. Intraoperative left atrial ablation (for atrial fibrillation) using a new argon cryocatheter: early clinical experience. Ann Thorac Surg 2003; 76: 1711-1715.
15. Ad N, Henry L, Hunt S. The concomitant cryosurgical Cox-Maze procedure using Argon based cryoprobes: 12 month results. J Cardiovasc Surg (Torino) 2011; 52: 593-599.
16. Viola N, Williams MR, Oz MC, Ad N. The technology in use for the surgical ablation of atrial fibrillation. Semin Thorac Cardiovasc Surg 2002; 14: 198-205.
17. Badhwar V, Rankin JS, Ad N, Grau-Sepulveda M, Damiano RJ, Gillinov AM, McCarthy PM, Thourani VH, Suri RM, Jacobs JP, Cox JL. Surgical ablation of atrial fibrillation in the United States: trends and propensity matched outcomes. Ann Thorac Surg 2017; 104: 493-500.
18. Schaff HV, Dearani JA, Daly RC, Orszulak TA, Danielson GK. Cox-Maze procedure for atrial fibrillation: Mayo Clinic experience. Semin Thorac Cardiovasc Surg 2000; 12: 30-37.
19. Mitchell MA, McRury ID, Everett TH, Li H, Mangrum JM, Haines DE. Morphological and physiological characteristics of discontinuous linear atrial ablations during atrial pacing and atrial fibrillation. J Cardiovasc Electrophysiol 1999; 10: 378-386.
20. Melby SJ, Lee AM, Zierer A, Kaiser SP, Livhits MJ, Boineau JP, Schuessler RB, Damiano RJ Jr. Atrial fibrillation propagates through gaps in ablation lines: implications for ablative treatment of atrial fibrillation. Heart Rhythm 2008; 5: 1296-1301.
Copyright: © 2020 Polish Society of Cardiothoracic Surgeons (Polskie Towarzystwo KardioTorakochirurgów) and the editors of the Polish Journal of Cardio-Thoracic Surgery (Kardiochirurgia i Torakochirurgia Polska). This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) License (http://creativecommons.org/licenses/by-nc-sa/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material, provided the original work is properly cited and states its license.
Quick links
© 2020 Termedia Sp. z o.o. All rights reserved.
Developed by Bentus.
PayU - płatności internetowe