Minimally invasive surgical ablation of atrial fibrillation: Six-month results

The Society of Thoracic Surgeons 2023 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation

The Society of Thoracic Surgeons 2023 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation incorporate the most recent evidence for surgical ablation and left atrial appendage occlusion in different clinical scenarios. Substantial new evidence regarding the risks and benefits of surgical left atrial appendage occlusion and the long-term benefits of surgical ablation has been produced in the last 5 years. Compared with the 2017 clinical practice guideline, the current update has an emphasis on surgical ablation in first-time, nonemergent cardiac surgery and its long-term benefits, an extension of the recommendation to perform surgical ablation in all patients with atrial fibrillation undergoing first-time, nonemergent cardiac surgery, and a new class I recommendation for left atrial appendage occlusion in all patients with atrial fibrillation undergoing first-time, nonemergent cardiac surgery. Further guidance is provided for patients with structural heart disease and atrial fibrillation being considered for transcatheter valve repair or replacement, as well as patients in need of isolated left atrial appendage management who are not candidates for surgical ablation. The importance of a multidisciplinary team assessment, treatment planning, and long-term follow-up are reiterated in this clinical practice guideline with a class I recommendation, along with the other recommendations from the 2017 guidelines that remained unchanged in their class of recommendation and level of evidence.

Long-Term Results of the Mini Maze Standalone Bi-Atrial Surgical Ablation: A 10-Year Follow-Up

Background: One way to treat atrial fibrillation is through surgical ablation. However, the literature only provides information on patient follow-up results for up to 5 years. Methods: In order to assess long-term monitoring data over ten years, this retrospective study included 58 patients with paroxysmal or persistent atrial fibrillation who underwent Mini Maze surgical ablation at Santaros Clinics between 1 February 2009 and 1 June 2014. The follow-up time after surgery was 144 ± 48 months. We evaluated the absence of atrial fibrillation, echocardiographic and clinical parameters, and EHRA score. Results: Sinus rhythm remained in 69.4%, 75.5%, 55.6%, and 44.1% of patients with paroxysmal AF, and 68,2%, 59.1%, 50%, and 41.9% of patients with persistent AF (p = 0.681). In the post-operative period, one patient (1.7%) had a transient ischemic attack, and another patient (1.7%) had a thoracotomy for post-operative bleeding. A total of 20% of patients were diagnosed with a post-operative respiratory tract infection. EHRA scores showed that patients' quality of life improved after they underwent Mini Maze surgical ablation. Conclusions: Despite AF recurrences after surgery, quality of life remains better than before surgery, showing that Mini Maze surgery is an effective and safe second-line treatment method for atrial fibrillation.

Variability of baroreceptor reflex assessed by tilt table test in a patient undergoing pulmonary vein isolation

BACKGROUND

The autonomic nervous system (ANS) plays a significant role in atrial fibrillation (AF). Catheter ablation (CA) affects the ANS balance. The assessment of baroreceptor (BR) function is an established method to measure parasympathetic activity; however, it has been rarely used in patients undergoing CA of AF.

AIMS

This study is to assess changes in BR function caused by CA and to compare these changes between two different types of CA: point-by-point radiofrequency (RF) versus cryoballoon (CB).

METHODS

In this observational, prospective, single center study, 78 patients (25 females, mean age 58 ± 9) with paroxysmal AF and first CA were included: 39 patients (RF group) and 39 (CB group). The BR function was assessed non-invasively using tilt testing and three parameters: event count (BREC) depicting overall BR activity, slope mean depicting BR sensitivity (BRS), and BR effectiveness index (BEI).

RESULTS

The groups did not differ in clinical or demographic data. Before CA, tilting caused a marked decrease in BR function parameters in the whole study group (BREC (29 ± 14.0-50.0 vs 28 ± 9.0-44.0, p < 0.068), BRS (10.2 ± 7.1-13.2 vs 5.8 ± 4.9-8.5; p < 0.001), and BEI (52.9 ± 39.9-65.5 vs 39.6 ± 23.6-52.1; p < 0.001), supine vs tilting, respectively). These changes were similar in the both groups. After CA, BR function decreased in the whole group (BREC 12.0 ± 3.0-22.0 vs 6.0 ± 3.0-18.0, p = 0.004; BRS 4.8 ± 3.6-6.8 vs 4.0 ± 3.0-5.8, p = 0.014; BEI 18.7 ± 8.3-27.4 vs 12.0 ± 5.1-21.0, p = 0.009). BREC was significantly more decreased in the CB vs RF. Similar trend was noted for BRS and BEI.

CONCLUSIONS

CA significantly affects BR function. These changes were more pronounced following CB rather than RF CA.

The Minimum Number of Ablation Lines for Complete Isolation of the Pulmonary Veins during Thoracoscopic Ablation for Atrial Fibrillation

Total thoracoscopic ablation has been recommended as a class IIa indication for atrial fibrillation. However, the optimal number of ablation lines for pulmonary vein isolation has not yet been proposed. This study aimed to report the minimum number of ablation lines required to achieve an intraoperative conduction block. This study included a total of 20 patients who underwent total thoracoscopic ablation from December 2020 to July 2021. The epicardial conduction block was checked after each ablation line of pulmonary vein antral clamping. The median age was 61 years old. The median duration of atrial fibrillation since the first diagnosis was 78 months. Pulmonary vein isolation with bidirectional conduction block was confirmed in 90% of patients. A median of six ablation lines around each pulmonary vein antrum were performed according to our protocol even after the conduction block was verified. The median number of ablations to achieve an exit block was two on the right side and 3.5 on the left side. We found that most conduction blocks were achieved within three ablations around the pulmonary vein antrum. Our results may provide evidence to reduce the number of unnecessary ablation lines in the future.

Ganglionated Plexi Ablation for the Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and is associated with significant morbidity and mortality. The autonomic nervous system (ANS) plays an important role in the initiation and development of AF, causing alterations in atrial structure and electrophysiological defects. The intrinsic ANS of the heart consists of multiple ganglionated plexi (GP), commonly nestled in epicardial fat pads. These GPs contain both parasympathetic and sympathetic afferent and efferent neuronal circuits that control the electrophysiological properties of the myocardium. Pulmonary vein isolation and other cardiac catheter ablation targets including GP ablation can disrupt the fibers connecting GPs or directly damage the GPs, mediating the benefits of the ablation procedure. Ablation of GPs has been evaluated over the past decade as an adjunctive procedure for the treatment of patients suffering from AF. The success rate of GP ablation is strongly associated with specific ablation sites, surgical techniques, localization techniques, method of access and the incorporation of additional interventions. In this review, we present the current data on the clinical utility of GP ablation and its significance in AF elimination and the restoration of normal sinus rhythm in humans.

Atrial fibrillation surgery with a focus on patients with reduced left ventricular function and heart failure

This review article aims to give an overview on the different surgical treatment options for atrial fibrillation It includes concomitant- as well as stand-alone surgical ablation therapy and outlines the main issues in patients with heart failure and reduced LVEF.

Predictive risk factors for recurrent atrial fibrillation after modified endoscopic ablation: A 2-year follow-up

BACKGROUND

Our previous study reported a modified endoscopic procedure for nonvalvular atrial fibrillation (AF) that requires only 3 ports in the left chest wall.

HYPOTHESIS

Certain preoperative variables might be predictive risk factors for AF recurrence among patients who underwent this procedure.

METHODS

From October 2010 to April 2014, 114 patients with either paroxysmal AF (PAF) or nonparoxysmal AF (non-PAF) underwent the procedure and completed postoperative cardiac-rhythm measurement via electrocardiography and Holter monitoring. Univariate and multivariate analyses of the possible AF-related risk factors were conducted.

RESULTS

During 2-year follow-up, 99 of 114 patients (86.8%) were free from atrial tachyarrhythmia. Results from univariate analyses showed that AF duration, left atrial diameter (LAD), left atrial minimum volume, left atrial empty fraction, left atrial expansion index, and left atrial active empty fraction (LAAEF) were significantly associated with postoperative AF recurrence. Results from multivariate analyses showed that AF duration (odds ratio [OR]: 1.194, 95% CI: 1.063-1.340, P = 0.003), LAD (OR: 1.101, 95% CI: 1.005-1.205, P = 0.039), and LAAEF (OR: 0.490, 95% CI: 0.277-0.865, P = 0.014) were independent risk factors. There was no difference in AF recurrence between patients with PAF and non-PAF (P = 0.250).

CONCLUSIONS

Our 2-year follow-up study suggested that low LAAEF, long AF duration, and large LAD might be potential predictive risk factors for AF recurrence. Patients with PAF and non-PAF had a similar AF recurrence rate after modified endoscopic ablation.

The Society of Thoracic Surgeons 2017 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation

EXECUTIVE SUMMARY

Surgical ablation for atrial fibrillation (AF) can be performed without additional risk of operative mortality or major morbidity, and is recommended at the time of concomitant mitral operations to restore sinus rhythm. (Class I, Level A) Surgical ablation for AF can be performed without additional operative risk of mortality or major morbidity, and is recommended at the time of concomitant isolated aortic valve replacement, isolated coronary artery bypass graft surgery, and aortic valve replacement plus coronary artery bypass graft operations to restore sinus rhythm. (Class I, Level B nonrandomized) Surgical ablation for symptomatic AF in the absence of structural heart disease that is refractory to class I/III antiarrhythmic drugs or catheter-based therapy or both is reasonable as a primary stand-alone procedure, to restore sinus rhythm. (Class IIA, Level B randomized) Surgical ablation for symptomatic persistent or longstanding persistent AF in the absence of structural heart disease is reasonable, as a stand-alone procedure using the Cox-Maze III/IV lesion set compared with pulmonary vein isolation alone. (Class IIA, Level B nonrandomized) Surgical ablation for symptomatic AF in the setting of left atrial enlargement (≥4.5 cm) or more than moderate mitral regurgitation by pulmonary vein isolation alone is not recommended. (Class III no benefit, Level C expert opinion) It is reasonable to perform left atrial appendage excision or exclusion in conjunction with surgical ablation for AF for longitudinal thromboembolic morbidity prevention. (Class IIA, Level C limited data) At the time of concomitant cardiac operations in patients with AF, it is reasonable to surgically manage the left atrial appendage for longitudinal thromboembolic morbidity prevention. (Class IIA, Level C expert opinion) In the treatment of AF, multidisciplinary heart team assessment, treatment planning, and long-term follow-up can be useful and beneficial to optimize patient outcomes. (Class I, Level C expert opinion).

Contact forces during hybrid atrial fibrillation ablation: an in vitro evaluation

PURPOSE

Data on epicardial contact force efficacy in dual epicardial-endocardial atrial fibrillation ablation procedures are lacking. We present an in vitro study on the importance of epicardial and endocardial contact forces during this procedure.

METHODS

The in vitro setup consists of two separate chambers, mimicking the endocardial and epicardial sides of the heart. A circuit, including a pump and a heat exchanger, circulates porcine blood through the endocardial chamber. A septum, with a cut out, allows the placement of a magnetically fixed tissue holder, securing porcine atrial tissue, in the middle of both chambers. Two trocars provide access to the epicardium and endocardium. Force transducers mounted on both catheter holders allow real-time contact force monitoring, while a railing system allows controlled contact force adjustment. We histologically assessed different combinations of epi-endocardial radiofrequency ablation contact forces using porcine atria, evaluating the ablation's diameters, area, and volume.

RESULTS

An epicardial ablation with forces of 100 or 300 g, followed by an endocardial ablation with a force of 20 g did not achieve transmurality. Increasing endocardial forces to 30 and 40 g combined with an epicardial force ranging from 100 to 300 and 500 g led to transmurality with significant increases in lesion's diameters, area, and volumes.

CONCLUSIONS

Increased endocardial contact forces led to larger ablation lesions regardless of standard epicardial pressure forces. In order to gain transmurality in a model of a combined epicardial-endocardial procedure, a minimal endocardial force of 30 g combined with an epicardial force of 100 g is necessary.

Surgical Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is the most common chronic arrhythmia in the adult population. Ablation lines have largely replaced the historical and challenging cut and sew techniques. Surgical ablation of AF is commonly performed in cases with other indications for cardiac surgery and less commonly as a stand-alone therapy. Pulmonary vein isolation is the cornerstone of this procedure. Extended left atrial ablation lines may increase efficacy in cases with longstanding persistent or permanent AF. Additional efficacy by adding right atrial ablation is controversial but is often performed in cases undergoing right atrial or atrial septal surgery. Left atrial volume reduction is recommended in cases with large left atria and AF undergoing another cardiac surgery. Arrhythmia recurrence is not uncommon after surgical ablation of AF and varies among studies due to heterogeneity in patient population, lesion set and endpoints. Freedom from AF recurrence was 65-87% at 12 months and 58-70% at 2 years follow-up. Long-term monitoring is recommended due to an increased prevalence of asymptomatic recurrences. The strongest predictors of AF recurrence are longstanding or persistent AF and a large left atrium. The most common mechanisms of recurrence are pulmonary vein reconnection, nonpulmonary vein triggers, and gaps in the ablation lines. About 20% of atrial tachyarrhythmia recurrences are atrial flutter or atrial tachycardia. There are not enough data in the surgical literature to support withdrawal of anticoagulation after surgical AF ablation. Patients selected for stand-alone surgical ablation usually have low risk profiles and low postoperative mortality rates (0.2%).

Is ganglionated plexi ablation during Maze IV procedure beneficial for postoperative long-term stable sinus rhythm?

BACKGROUND

We investigated the role of surgical ablation targeting the autonomous nervous system during a Cox-Maze IV procedure in the maintenance of sinus rhythm at long-term follow-up.

METHODS

The patient population consisted of 519 subjects with persistent or long-standing persistent atrial fibrillation (AF) undergoing radiofrequency Maze IV during open heart surgery between January 2006 and July 2013 at three institutions without (Group 1) or with (Group 2) ganglionated plexi (GP) ablation. Recurrence of atrial fibrillation off-antiarrhythmic drugs was the primary outcome. Predictors of AF recurrence were evaluated by means of competing risk regression. Median follow-up was 36.7 months.

RESULTS

The percentage of patients in normal sinus rhythm (NSR) off-antiarrhythmic drugs did not differ between groups (Group 1-75.5%, Group 2-67.8%, p = 0.08). Duration of AF ≥ 38 months (p = 0.01), left atrial diameter ≥ 54 mm (0.001), left atrial area ≥ 33 cm(2) (p = 0.005), absence of connecting lesions (p= 0.04), and absence of right atrial ablation (p < 0.001) were independently associated with high incidence of AF recurrence. In contrast the absence of GP ablation was not a significant factor (p = 0.12).

CONCLUSIONS

GP ablation did not prove to be beneficial for postoperative stable NSR. A complete left atrial lesion set and biatrial ablation are advisable for improving rhythm outcomes. Randomized controlled trials are necessary to confirm our findings.

Surgical ablation of atrial fibrillation

Surgical ablation of atrial fibrillation (AF) is currently performed in many major hospitals throughout the world. This paper reviews the development of surgical procedures for AF ablation. It is hoped that the paper can provide a foundation for those involved with ablation of AF to improve patient care. AF is triggered by a rapidly firing focus and could be treated with a localized ablation procedure. A large body of literature has confirmed the safety and efficacy of surgical ablation of AF. New ablation technologies have simplified the surgical treatment of AF and expanded the indications. Generally, more extensive lesion sets have had better long-term outcomes. Despite the tremendous progress that has been made in the development of surgical ablation of AF, many questions remain unanswered. It is anticipated that well designed clinical trials will continue to provide solid evidence to help formulate practice guidelines in the future.

Atrial fibrillation therapy now and in the future: drugs, biologicals, and ablation

Atrial fibrillation (AF) is a complex disease with multiple inter-relating causes culminating in rapid, seemingly disorganized atrial activation. Therapy targeting AF is rapidly changing and improving. The purpose of this review is to summarize current state-of-the-art diagnostic and therapeutic modalities for treatment of AF. The review focuses on reviewing treatment as it relates to the pathophysiological basis of disease and reviews preclinical and clinical evidence for potential new diagnostic and therapeutic modalities, including imaging, biomarkers, pharmacological therapy, and ablative strategies for AF. Current ablation and drug therapy approaches to treating AF are largely based on treating the arrhythmia once the substrate occurs and is more effective in paroxysmal AF rather than persistent or permanent AF. However, there is much research aimed at prevention strategies, targeting AF substrate, so-called upstream therapy. Improved diagnostics, using imaging, genetics, and biomarkers, are needed to better identify subtypes of AF based on underlying substrate/mechanism to allow more directed therapeutic approaches. In addition, novel antiarrhythmics with more atrial specific effects may reduce limiting proarrhythmic side effects. Advances in ablation therapy are aimed at improving technology to reduce procedure time and in mechanism-targeted approaches.

Histopathologic analysis of atrial tissue in patients with atrial fibrillation: comparison between patients with atrial septal defect and patients with mitral valvular heart disease

BACKGROUND

Atrial fibrillation (AF) in adult patients with atrial septal defect (ASD) accompanies an enlarged right atrium (RA) with a less enlarged left atrium (LA), which is the opposite situation in patients with AF and mitral valvular disease. This study was to compare the histopathological change in the atrium of patients with AF of two different etiologies: ASD and mitral disease.

METHODS

Twenty-four patients were enrolled. Group 1 included patients with ASD (8), Group 2 included patients with ASD with AF (6), and Group 3 included patients with mitral disease with AF (10). Preoperative atrial volumes were measured. Atrial tissues were obtained during surgical procedures and stained with periodic acid-Schiff, smooth muscle actin, Sirius red, and Masson's trichrome to detect histopathologic changes compatible with AF. The severity of histopathological changes was represented with "positivity" and "strong positivity" after analyzing digitalized images of the staining. We investigated the relationship between the degree of atrial dilatation and severity of histopathological changes according to the groups and tissues.

RESULTS

Group 2 and Group 3 patients showed a tendency toward an enlarged RA volume and enlarged LA volume, respectively, compared with each others. However, in the histopathologic analysis, "positivity" and "strong positivity" showed no significant positive correlations with the degree of atrial volume in special staining.

CONCLUSIONS

A similar degree of histopathologic changes was observed in both atria in patients with AF (Group 2 and 3) regardless of the degree of dilatation of atrial volume and disease entities.

Paracardioscopic ex-maze procedure for atrial fibrillation

The paracardioscopic ex-maze (PEX) procedure is a totally endoscopic, minimally invasive surgical procedure for the correction of all types of atrial fibrillation. The PEX is performed on the epicardial surface of the beating heart without the use of cardiopulmonary bypass. Access to the pericardium is via a novel transdiaphragmatic approach using a cannula to access the posterior heart. Additionally, right chest thoracoscopy provides access to the right epicardium to complete a bi-atrial ablation pattern. A unipolar, irrigated radiofrequency device is used to create the epicardial lesions. Because the lesions are created on the epicardium, lesion contiguity can be verified by visual observation. Also, as the heart is beating, conversion to sinus rhythm can be directly observed during the procedure and pulmonary vein isolation/exit block can be verified after lesion creation.

The surgical treatment for atrial fibrillation: ablation technology and surgical approaches

The Cox maze procedure developed originally in 1987 by Dr James Cox has evolved from a "cut and sew" surgical procedure, where the maze was applied using multiple surgical cuts, to an extensive use of surgical ablation technology where ablation lesions are placed with alternative energy sources (radiofrequency, cryothermy, microwave, and high-frequency ultrasound). Furthermore, the procedure has changed from a median sternotomy approach only to one that can be performed minimally invasively and robotically. The purpose of this paper is to review the current available technology for the ablation of atrial fibrillation as well as the different procedural approaches for the surgical ablation of atrial fibrillation.

Right atrial lesions do not improve the efficacy of a complete left atrial lesion set in the surgical treatment of atrial fibrillation, but they do increase procedural morbidity

OBJECTIVE

Some have suggested the superiority of biatrial versus left atrial lesions. We sought to analyze our experience.

METHODS

We retrospectively reviewed 305 consecutive patients from 2007 to 2011. Rhythm success was defined as freedom from atrial fibrillation (AF) or flutter determined by 12-lead electrocardiograms at 3-month intervals. Lesions sets were pulmonary vein isolation (PVI), left-extended (PVI + mitral valve annulus [MV] lesion ± left atrial appendage lesion [LAA]) or biatrial-extended (right atrial ablation + PVI + MV ± LAA).

RESULTS

The success rates of PVI, left-extended, and biatrial-extended lesions were as follows: at 3 months, 56.7%, 74.7%, and 79.4% (P = .003); at 6 months, 56.9%, 72.9%, and 74.6% (P = .02); at 9 months, 54.6%, 72.5%, and 83.3% (P < .001); and at 12 months, 52.6%, 76.1%, and 80.0% (P < .001). Biatrial lesions had a higher rate of pacemaker placement than did left atrial lesions (16.5% vs 7.5%; P = .02). When we grouped patients by left lesion (PVI, PVI + MV, PVI + MV + LAA) irrespective of right atrial ablation, success was as follows: 3 months, 57.9%, 71.1%, and 87.8% (P < .01); 6 months, 58.1%, 71.6%, and 77.6% (P = .03); 9 months, 55.9%, 71.3%, and 89.6% (P < .01); and 12 months, 54.1%, 74.7%, and 83.7% (P < .01).

CONCLUSIONS

PVI is associated with lower rhythm success than an extended left atrial lesion set. The addition of a right atrial lesion to an extended left atrial lesion set does not improve efficacy, but it does increase the rate of pacemaker placement for sinus dysfunction. Adding an LAA lesion may confer additional efficacy when added to a lesion set that includes PVI + MV.

Totally Thoracoscopic Surgical Ablation or Catheter Ablation of Atrial Fibrillation: A Systematic Review and Preliminary Meta-Analysis

This article provides results of a preliminary meta-analysis of the stand-alone atrial fibrillation (AF) surgical publications from 2009 to 2011. In 6 studies with postoperative freedom from AF as primary end point, the meta-analysis indicated an overall success rate of 84% (95% confidence interval [CI], 80.0-88.0). For the 7 studies with the primary end point of postoperative return to normal sinus rhythm, the success rate was 83% (95% CI, 79.0-87.0). These data are compared with 3 comprehensive meta-analyses of catheter ablation. Based on comparison, it is recommended that initial treatment of long-standing persistent atrial fibrillation be minimal access surgery.

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.

Feasibility and efficacy of minimally invasive stand-alone surgical ablation of atrial fibrillation. A single-center experience

PURPOSE

Minimally invasive surgical ablation for atrial fibrillation (AF) has shown good results and low complications incidence. Our objective was to evaluate feasibility and efficacy of this technique in our center.

METHODS

The procedure included pulmonary vein isolation, ganglionic plexi ablation, ligament of Marshall resection, and left atrial appendage exclusion through beating heart minimally invasive bilateral thoracotomies. Patients were monitored daily by telemedicine during the first 4 months and then by quarterly 24-h Holter monitoring or by implantable cardiac monitor. Ablation success was defined as freedom from any atrial tachyarrhythmia recurrence lasting more than 30 s and from antiarrhythmic drugs. All patients were followed up for a minimum of 12 months.

RESULTS

Twenty-two consecutive patients with AF, paroxysmal in 27% and persistent in 73%, were treated. Mean age was 63 ± 10 years, 86% were men. Seventy-three percent of patients had previously undergone to one or more catheter ablations. Median follow-up period was 22 months (25°-75° percentile, 20-27). Patients free from any arrhythmia recurrence for at least 6 consecutive months discontinued antiarrhythmic therapy. Ablation was successful in 73% of patients at 12 months. Freedom from AF recurrences independently from antiarrhythmic therapy status was 91% at 12 months. Results were consistent in patients that reached 24 months follow-up. There were no deaths. Complications were: one conversion to sternotomy owing to thoracic adherences, one pacemaker implant, and one postoperative hemothorax requiring surgical revision.

CONCLUSIONS

Our results show that minimally invasive surgical ablation was feasible and gave satisfactory results at long-term term follow-up in patients with AF.

Minimally invasive surgical implantation of the percutaneous left atrial appendage transcatheter occlusion device: initial experience in a canine model

OBJECTIVE

Atrial fibrillation (AF) is a significant cause of thromboembolism and stroke. Left atrial appendage (LAA) occlusion is associated with a decreased risk of stroke in patients with AF. Percutaneous implantation of the percutaneous LAA transcatheter occlusion (PLAATO) device has shown reduction in stroke risk and decreased need for anticoagulation. A surgical method of PLAATO implantation is proposed for its utility and efficacy in cardiac surgical procedures, where LAA occlusion is indicated as a primary procedure or as an adjunct. We describe a surgical method for PLAATO deployment in an experimental model that simulates various operative scenarios including right minithoracotomy, right video-assisted thoracoscopic, or median sternotomy.

METHODS

The PLAATO LAA occlusion device was deployed into the LAA in six dogs using a right minithoracotomy incision and catheter deployment via direct left atrial access. Intracardiac echocardiography and left atrial angiography were used to size, position, and verify proper deployment of the device.

RESULTS

Successful PLAATO deployment was achieved in six of the six dogs. One dog required replacement of an undersized device. One dog required replacement of an oversized device. Four dogs required minor repositioning for optimal positioning. Complete flush occlusion of the LAA was achieved in three dogs; the other three dogs had trace leak by LAA angiography.

CONCLUSIONS

Experimental surgical implantation of the PLAATO device produces stable and complete occlusion of the LAA. Potential surgical indications for PLAATO implantation include patients with AF where a percutaneous approach to LAA occlusion is contraindicated or in patients with AF who require concurrent cardiac surgery.

Minimally invasive video-assisted cardiac surgery: operative techniques, application fields and clinical outcomes

Minimally invasive video-assisted surgery through a right minithoracotomy has become the standard surgical approach for several cardiac diseases at many major centers worldwide. In this article we review the existing literature on the subject and describe different operative techniques, application fields and clinical outcomes.