Hybrid ablation for atrial fibrillation: a systematic review

Comparing simultaneous hybrid ablation with stand-alone thoracoscopic surgical ablation for the treatment of non-paroxysmal atrial fibrillation: a prospective randomized controlled trial

AIMS

Advanced atrial fibrillation (AF) is currently a dilemma for electrophysiologists when choosing a minimally invasive treatment strategy. Previous studies have demonstrated the outcome of either catheter ablation or thoracoscopic surgical ablation (SA) is unsatisfactory in these patients. Whether hybrid ablation (HA) could improve outcomes in these patients is unknown. The purpose of this study was to evaluate the clinical efficacy of HA for the treatment of advanced AF.

METHODS AND RESULTS

A randomized controlled trial was designed to enrol patients with persistent AF (PerAF) and enlarged left atrium or long-standing persistent AF (LSPAF) who were randomized to HA or thoracoscopic SA at a 1:1 ratio. The primary endpoint was freedom from any recurrence of AF off antiarrhythmic drugs (AADs) 12 months after operation. The primary endpoint was monitored by 7-day electrocardiogram monitoring devices. One hundred patients were enrolled. The mean age was 58.5 ± 7.6 years, and the mean left atrial diameter (LAD) was 50.1 ± 6.1 mm. At 12 months, freedom from AF off AADs was recorded in 71.4% (35/49) of patients in HA group and 45.8% (22/48) in SA group [odds ratio 2.955, 95% confidence interval (1.275-6.848), P = 0.014]. HA significantly reduced patients' AF burden (30.2% in SA group and 14.8% in HA group, P = 0.048) and the LAD (mean differences: -5.53 ± 4.97 mm in HA group and -3.27 ± 5.20 mm in SA group, P = 0.037) at 12 months after operation.

CONCLUSION

In patients with PerAF and enlarged left atrium or LSPAF, HA achieved better freedom from AF after 1 year of follow-up compared with thoracoscopic SA.

Hybrid atrial fibrillation ablation

In this state-of-the art review on hybrid atrial fibrillation (AF) ablation, we briefly focus on the pathophysiology of AF, the rationale for the hybrid approach, its technical aspects and the efficacy and safety outcomes after hybrid AF ablation, both from meta-analyses and randomized control trial data. Also, we performed a systematic search to provide a provisional overview of real-world hybrid AF ablation efficacy and safety outcomes. Furthermore, we give an insight into the 'Maastricht approach', an approach that allows us to tailor the ablation procedure to the individual patient. Finally, we reflect on future perspectives with the objective to continue improving our thoracoscopic hybrid AF ablation approach. Based on the review of the available literature, we believe it is fair to state that thoracoscopic hybrid AF ablation is a valid alternative to catheter ablation for the treatment of patients with more persistent forms of AF.

Hybrid Endo-Epicardial Therapies for Advanced Atrial Fibrillation

Atrial fibrillation (AF) is a growing health problem that increases morbidity and mortality, and in most patients progresses to more advanced diseases over time. Recent research has examined the underlying mechanisms, risk factors, and progression of AF, leading to updated AF disease classification schemes. Although endocardial catheter ablation is effective for early-stage paroxysmal AF, it consistently achieves suboptimal outcomes in patients with advanced AF. Identification of the factors that lead to the increased risk of treatment failure in advanced AF has spurred the development and adoption of hybrid ablation therapies and collaborative heart care teams that result in higher long-term arrhythmia-free survival. Patients with non-paroxysmal AF, atrial remodeling, comorbidities, or AF otherwise deemed difficult to treat may find hybrid treatment to be the most effective option. Future research of hybrid therapies in advanced AF patient populations, including those with dual diagnoses, may provide further evidence establishing the safety and efficacy of hybrid endo-epicardial ablation as a first line treatment.

Mid-term success rate of single stage hybrid ablation of persistent and long-term persistent atrial fibrillation

INTRODUCTION

Single stage thoracoscopic radiofrequency ablation (RFA) is a treatment method for persistent and long-term persistent atrial fibrillation (AF) offering the possibility for patients otherwise inconsolable by conventional catheter RFA. We present a pilot group of patients after the introduction of the new method at our clinical center. Patients group: A total of 52 patients aged 61.82 ± 9.7 years underwent single stage hybrid ablation (thoracoscopic isolation of pulmonary veins and box lesion followed by catheter verification of the surgical procedure effectivness) for symptomatic persistent and long-term persistent AF with significantly dilated left atrium 57.9 ± 11.0mm in the period September 2016-March 2019.

RESULTS

The median duration of the procedure was 232 minutes and the median duration of hospitalization was 10 days. At discharge, 52 patients (100%) had sinus rhythm. 48 of 52 patients (92.3%) had a 6-month follow-up. 41 of 48 (85.4%) and 38 of 44 (86.4%) of patients were AF free at 3-month and 6-month follow-up, respectively. Acute complications were: one left atrial perforation resolved successfully by suture and one transient ischaemic attack without permanent sequelae. Late complications involved one massive pulmonary embolization and an atrioesophageal fistula. There was no periprocedural myocardial infarction or stroke with permanent sequelae.

CONCLUSION

Hybrid thoracoscopic-catheter ablation performed during one procedure is an effective and relatively safe mini-invasive method of treatment for long-term persistent atrial fibrillation.

Epicardial origin of cardiac arrhythmias: clinical evidences and pathophysiology

Recent developments in imaging, mapping, and ablation techniques have shown that the epicardial region of the heart is a key player in the occurrence of ventricular arrhythmic events in several cardiac diseases, such as Brugada syndrome, arrhythmogenic cardiomyopathy, or dilated cardiomyopathy. At the atrial level as well, the epicardial region has emerged as an important determinant of the substrate of atrial fibrillation, pointing to common underlying pathophysiological mechanisms. Alteration in the gradient of repolarization between myocardial layers favouring the occurrence of re-entry circuits has largely been described. The fibro-fatty infiltration of the subepicardium is another shared substrate between ventricular and atrial arrhythmias. Recent data have emphasized the role of the epicardial reactivation in the formation of this arrhythmogenic substrate. There are new evidences supporting this structural remodelling process to be regulated by the recruitment of epicardial progenitor cells that can differentiate into adipocytes or fibroblasts under various stimuli. In addition, immune-inflammatory processes can also contribute to fibrosis of the subepicardial layer. A better understanding of such ‘electrical fragility’ of the epicardial area will open perspectives for novel biomarkers and therapeutic strategies. In this review article, a pathophysiological scheme of epicardial-driven arrhythmias will be proposed.

One-Stage Versus Sequential Hybrid Radiofrequency Ablation: An In Vitro Evaluation

Objective

To compare lesion size and depth between a 1-step, a sequential, and a delayed radio-frequency ablation in a hybrid setup.

Methods

Left atrium tissues obtained from fresh porcine hearts were mounted into the ABLABOX simulator. Based on the time differences between the index epicardial (epi) and consequent endocardial (endo) ablation, 3 study groups were compared: a 1-stage (SEQ- 0) group (0-minute delay), an SEQ 1 group (60-minute delay), and an SEQ 2 group (240-minute delay). During the experiment, a constant epicardial (300 gr) and endocardial (30 gr) force were applied. Per group, 20 samples were studied, and the resulting lesion size and depth were quantified with morphometric evaluation.

Results

Overall, no transmural lesion was obtained. Lesions in SEQ 0 had better maximum and minimum diameters ( P < 0.001), a larger total area ( P < 0.001), and volume ( P < 0.001) than SEQ 1 and SEQ 2. There was no statistical difference in morphometric parameters (all, P > 0.05) between the delayed procedures (SEQ 1 and SEQ 2).

Conclusions

In our in vitro model, different time sequences of combined epi–endo ablation did not result in transmural lesions. However, simultaneous epi–endo ablation produced broader and deeper lesions. Our findings need to be confirmed by further research.

Convergent epicardial-endocardial ablation for treatment of long-standing persistent atrial fibrillation: A review of literature

BACKGROUND AND AIM OF STUDY

The convergent procedure (CVP) is a hybrid ablation technique via a subxiphoid incision that has recently emerged as a treatment option for non-paroxysmal atrial fibrillation (npAF). By combining endocardial and epicardial ablation into a simultaneous or staged procedure, the pulmonary vein and posterior left atrium can be isolated with transmural lesion sets while minimizing the risk of proarrhythmic gaps that are a known limitation with endocardial linear lesion sets. We reviewed the 12-month outcomes in patients who underwent CVP compared to those who underwent endocardial catheter ablation (CA) and surgical ablation (SA).

METHODS

A literature search was conducted using the PubMed database for publications related to CVP. Selected studies included detailed 12-month follow-up of patients, patient characteristics, periprocedural complications, use of antiarrhythmic drugs (AADs), and monitoring method.

RESULTS

Five studies with 340 patients who underwent CVP between January 2009 and March 2017 were selected for this review. A total of 8.5% of patients had paroxysmal AF (pAF), 42.2% had persistent AF (peAF), and 49.1% had long-standing persistent AF (lspAF). At 12 months, 81.9% of patients were in sinus rhythm, while 54.1% of patients were in sinus rhythm while not taking AADs. The overall complication rate was 10%.

CONCLUSION

CVP had better 1-year efficacy in eliminating AF when compared to CA. However, SA, specifically the Cox Maze IV, had lower rates of AF recurrence in the npAF patient population. Despite its promising 1-year efficacy rates, the periprocedural complication rate for CVP was significantly higher than both CA and SA.

Hybrid surgical ablation for persistent or long standing persistent atrial fibrillation: A French single centre experience

BACKGROUND

Hybrid ablation for the treatment of atrial fibrillation is a single combined procedure consisting in a minimally thoracoscopic surgical ablation followed by a catheter ablation. This promising technique is recommended in persistent atrial fibrillation according to the current guidelines but is not routinely performed in France, mainly due to the absence of reimbursement by the French National Health Insurance.

AIMS

The aim of this prospective and single-centre study was to analyse, for the first time in France, the feasibility, efficacy and complication rates of hybrid ablation in patients with persistent atrial fibrillation.

METHODS

Hybrid ablation was performed in 15 consecutive patients (13 men, mean age 61±6 years) with persistent (7 patients) or long standing persistent (8 patients) atrial fibrillation.

RESULTS

Hybrid ablation was completed in 14/15 patients. Eleven patients returned in sinus rhythm during the procedure. Two patients (13%) had major per-procedural complications and 2 had minor complications. During an average follow-up of 25±6 months, 6 patients (40%) underwent a redo catheter ablation because of atrial tachycardia, mainly peri-mitral atrial flutter. At 1 year follow up, 14/15 patients were in sinus rhythm, including 11 free of antiarrhythmic drugs.

Small bowel obstruction secondary to diaphragmatic herniation following transabdominal cardiac ablation

We report an unusual case of strangulated diaphragmatic hernia secondary to a pericardial ablation, which resulted in necrosis of the incarcerated small bowel. Through a literature search, we have found a limited number of similar cases introducing a case series for this rare but potentially fatal condition.

Additional cavotricuspid isthmus ablation may reduce recurrent atrial tachyarrhythmia after total thoracoscopic ablation for persistent atrial fibrillation

OBJECTIVES

Unlike catheter ablation, little is known about the benefits of cavotricuspid isthmus (CTI) ablation in total thoracoscopic ablation (TTA) of atrial fibrillation (AF). This study aimed to investigate the incidence of recurrent atrial tachyarrhythmia (ATa) according to additional CTI ablation after TTA in patients with persistent AF.

METHODS

Among 208 consecutive patients who underwent TTA for persistent AF at the Samsung Medical Center from February 2012 to January 2016, a total of 63 patients with CTI ablation and 91 patients without CTI ablation were included in the final analysis. CTI ablation was performed in patients who had long-standing AF or atrial flutter episodes during the admission period.

RESULTS

There was no difference in baseline characteristics between the CTI ablation and non-CTI ablation groups, except for a higher number of male patients in the CTI ablation group. The CTI ablation group showed a significantly higher survival rate free from recurrent ATa than that of the non-CTI ablation group at 5 years (52.5% vs 41.4%, P = 0.046). In the multivariable analysis, CTI ablation (hazard ratio 0.46, 95% confidence interval 0.217-0.971; P = 0.042) and left atrial volume index (hazard ratio 1.05, 95% confidence interval 1.029-1.070; P < 0.001) were significantly correlated with recurrent ATa.

CONCLUSIONS

Patients with CTI ablation showed a better survival rate free from recurrent ATa compared with the non-CTI ablation group. The additional CTI ablation may reduce recurrent ATa after TTA in patients with documented atrial flutter or long-standing AF.

Hybrid thoracoscopic surgical and transvenous catheter ablation versus transvenous catheter ablation in persistent and longstanding persistent atrial fibrillation (HARTCAP-AF): study protocol for a randomized trial

Background

Success rates with conventional transvenous endocardial pulmonary vein isolation in patients with persistent and longstanding persistent atrial fibrillation (AF) are variable due to advanced electrical and structural remodeling of the atria. As a consequence, more extensive endocardial lesions, minimally invasive thoracoscopic surgical techniques, and hybrid ablation (combining thoracoscopic epicardial surgical and endocardial catheter ablation) have been developed.

Hypothesis

The HARTCAP-AF trial hypothesizes that hybrid AF ablation is more effective than (repeated) transvenous endocardial catheter ablation in (longstanding) persistent AF, without increasing the number of associated major adverse events.

Methods

This randomized controlled trial will include 40 patients with persistent or longstanding persistent AF who will be 1:1 randomized to either hybrid ablation or (repeated) catheter ablation. The procedures and follow-up are conducted according to the guidelines. The primary effectiveness endpoint is freedom from any supraventricular arrhythmia lasting longer than 5 min without the use of Vaughan-Williams class I or III antiarrhythmic drugs through 12 months of follow-up after the last procedure. In the catheter ablation arm, a second procedure planned within 6 months after the index procedure is allowed for obtaining the primary endpoint. Additionally, adverse events, cost-effectiveness, and quality of life data will be recorded.

Trial registration

ClinicalTrials.gov, NCT02441738. Registered on 12 May 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3365-9) contains supplementary material, which is available to authorized users.

Characteristics of symptomatic recurrent tachyarrhythmia after thoracoscopic ablation for persistent atrial fibrillation

BACKGROUND

Recurrent atrial tachyarrhythmia (ATa) is a challenge in all ablation procedures for atrial fibrillation (AF). However, data on ATa after totally thoracoscopic ablation (TTA) is lacking. This study aimed to investigate the mechanisms and outcomes of recurrent ATa after TTA.

METHODS

Eligible patients for the present study were those who underwent electrophysiologic study and catheter-based radiofrequency ablation (RFA) at least 3 months after TTA for symptomatic recurrent ATa that was refractory to antiarrhythmic drugs and/or cardioversion. Follow-up outcomes included recurrent ATa after first or repeated RFA.

RESULTS

A consecutive 154 TTA patients were evaluated. A total of 24 patients showed symptomatic recurrent ATa after TTA, and 22 underwent RFA. Half of the patients (11/22, 50%) had AF as a form of recurrent ATa. Nonpulmonary vein (PV)-related mechanisms of ATa were noted in half of patients. PV gaps showed a characteristic distribution: most gaps in right PVs were located at the posterior ridge (71.4%) with the posterior ridge of left PVs saved in all patients. Post-RFA recurrence rate was 27.3% during a median follow-up of 9.1 months, with all recurrences except for one occurring within 3 months after first RFA.

CONCLUSIONS

During a median of 17.8 months after TTA, 24 patients (24/154, 15.6%) developed symptomatic recurrent ATa, and 22 patients underwent RFA. Post-RFA recurrence rate was 27.3%, which mostly occurred within 3 months after RFA. Catheter-based ablation of recurrent arrhythmias may be effective, but challenging.

A Hybrid Maze Procedure for Long-Standing Persistent Atrial Fibrillation

BACKGROUND

Catheter ablation (CA) for long-standing persistent atrial fibrillation (LSPAF) is suboptimal, and open surgical ablation, although more successful, is too invasive to be a first-line therapy. Less invasive hybrid procedures that combine thoracoscopic surgery (TS) with CA have been only marginally more successful for LSPAF than CA alone.

METHODS

Joint hybrid procedures for LSPAF are based on the assumption that AF surgery and CA procedures can be guided by intraoperative mapping. However, intraoperative mapping is not always dependable because of the transient nature of the sustaining reentrant drivers. The best results in patients with LSPAF have been attained with the non-guided, anatomy-based surgical Maze-III and Maze-IV procedures. Likewise, a staged TS/CA hybrid procedure that creates a combination of lesions that adhere to the concept of a Maze pattern, that is, a Hybrid Maze-IV procedure, should be more effective for LSPAF.

RESULTS

Initial TS includes all lesions of the Maze-IV procedure except the mitral line, coronary sinus lesion, and one right atrial lesion. Follow-up CA at 3 months includes touching up any incomplete TS lesions, a cavotricuspid isthmus lesion, and a mitral line/coronary sinus lesion in the 10% to 15% of patients with post-TS perimitral flutter. This combination of TS and CA lesions creates a complete Maze-IV procedure.

CONCLUSIONS

It is possible to create the complete lesion pattern of a Maze-IV procedure with a staged TS/CA hybrid procedure. The success of this Hybrid Maze procedure in patients with LSPAF should be the same as that attained with an open surgical Maze-IV procedure.

The Effect of Atrial Fibrillation Ablation Techniques on P Wave Duration and P Wave Dispersion

BACKGROUND

A reduction in surface electrocardiogram (ECG) P wave duration and dispersion is associated with improved outcomes in atrial fibrillation ablation. We investigated the effects of different ablation strategies on P wave duration and dispersion, hypothesising that extensive left atrial (LA) ablation with left atrial posterior wall isolation would give a greater reduction in P wave duration than more limited ablation techniques.

METHODS

A retrospective analysis of ECGs from patients who have undergone atrial fibrillation (AF) ablation was performed and pre-procedural sinus rhythm ECGs were compared with the post procedure ECGs. Maximal P wave duration was measured in leads I or II, minimum P wave duration in any lead and values were calculated for P wave duration and dispersion. Left atrial dimensions and medications at the time of ECG were documented. Ablation strategies compared were; pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) and the persistent AF (PsAF) ablation strategies of pulmonary vein isolation plus additional linear lesions (Lines), left atrial posterior wall isolation via catheter (PWI) and left atrial posterior wall isolation via staged surgical and catheter ablation (Hybrid).

RESULTS

Sixty-nine patients' ECGs were analysed: 19 PVI, 21 Lines, 14 PWI, 15 Hybrid. Little correlation was seen between pre-procedure left atrial size and P wave duration (r=0.24) but LA size and P wave duration was larger in PsAF patients. A significant difference was seen in P wave reduction driven by Hybrid AF ablation (p<0.005) and Lines (<0.02). There was no difference amongst P wave dispersion between groups but the largest reduction was seen in the Hybrid ablation group.

CONCLUSIONS

P wave duration increased with duration of continuous atrial fibrillation. Hybrid AF ablation significantly reduced P wave duration and dispersion compared to other ablation strategies including posterior wall isolation via catheter despite this being the same lesion set.

The safety and efficacy of hybrid ablation for the treatment of atrial fibrillation: A meta-analysis

Introduction

Hybrid ablation, an emerging therapy that combines surgical intervention and catheter ablation, has become a viable option for the treatment of persistent atrial fibrillation. In this analysis, we aimed to evaluate the safety and efficacy of hybrid ablation, as well as compare the outcomes of one-step and staged approaches.

Methods

We conducted a search in major online databases and selected the studies that met the inclusion criteria. The primary endpoint was defined as no episode of atrial fibrillation or atrial tachycardia lasting longer than 30 seconds without administration of antiarrhythmic drugs.

Results

Sixteen studies including 785 patients (paroxysmal atrial fibrillation, n = 83; persistent atrial fibrillation, n = 214; long-standing persistent atrial fibrillation, n = 488) were selected. Average history of atrial fibrillation was (5.0±1.6) years. The pooled proportion of patients who were arrhythmia-free at the primary endpoint was 73% (95% CI, 64%–81%, Cochran’s Q, P<0.001; I² = 81%). The pooled rate of severe short-term complications was 4% (95% CI, 2%–7%, Cochran’s Q, P = 0.01; I² = 51%). The success rate after one-step procedures (69%) was lower than that after staged procedures (78%). The staged approach could ultimately prove to be safer, although complication rates were relatively low for both approaches (2% and 5%, respectively).

Conclusions

Hybrid ablation is an effective and generally safe procedure. The current data suggest that staged hybrid ablation could be the optimal approach, as it is associated with a higher success rate and a seemingly lower complication rate. Additional randomized controlled trials are necessary to confirm these results.

One-stage Approach for Hybrid Atrial Fibrillation Treatment

The one-stage approach for hybrid atrial fibrillation involves the simultaneous and close cooperation of different medical specialties. This review attempts to describe its challenging issues, exposing a plan to balance thrombotic risk and bleeding risk. It describes the combined surgical-electrophysiological procedure. Specific topics, involving hemodynamic, fluid and respiratory management during surgery are considered, and problems related to postoperative pain are surveyed.

Atrial Fibrillation in Heart Failure: a Therapeutic Challenge of Our Times

Atrial fibrillation (AF) and heart failure (HF) are growing cardiovascular disease epidemics worldwide. There has been an exponential increase in the prevalence of AF and HF correlating with an increased burden of cardiac risk factors and improved survival rates in patients with structural heart disease. AF is associated with adverse prognostic outcomes in HF and is most evident in mild-to-moderate left ventricular (LV) dysfunction where the loss of "atrial kick" translates into poorer quality of life and increased mortality. In the absence of underlying structural heart disease, arrhythmia can independently contribute to the development of cardiomyopathy. Together, these 2 conditions carry a high risk of thromboembolism due to stasis, inflammation and cellular dysfunction. Stroke prevention with oral anticoagulation (OAC) remains a mainstay of treatment. Pharmacologic rate and rhythm control remain limited by variable efficacy, intolerance and adverse reactions. Catheter ablation for AF has resulted in a paradigm shift with evidence indicating superiority over medical therapy. While its therapeutic success is high for paroxysmal AF, it remains suboptimal in persistent AF. A better mechanistic understanding of AF as well as innovations in ablation technology may improve patient outcomes in the future. Refractory cases may benefit from atrioventricular junction ablation and biventricular pacing. The value of risk factor modification, especially with regard to obesity, sleep apnea, hypertension and diabetes, cannot be emphasized enough. Close interdisciplinary collaboration between HF specialists and electrophysiologists is an essential component of good long-term outcomes in this challenging population.

Persistent atrial fibrillation vs paroxysmal atrial fibrillation: differences in management

INTRODUCTION

Atrial fibrillation (AF) is the most common human arrhythmia. AF is a progressive disease, initially being nonsustained and induced by trigger activity, and progressing towards persistent AF through alteration of the atrial myocardial substrate. Treatment of AF aims to decrease the risk of stroke and improve the quality of life, by preventing recurrences (rhythm control) or controlling the heart rate during AF (rate control). In the last 20 years, catheter-based and, less frequently, surgical and hybrid ablation techniques have proven more successful compared with drug therapy in achieving rhythm control in patients with AF. However, the efficiency of ablation techniques varies greatly, being highest in paroxysmal and lowest in long-term persistent AF. Areas covered: In this review, we discuss the fundamental differences between paroxysmal and persistent AF and the potential impact of those differences on patient management, emphasizing the available therapeutic strategies to achieve rhythm control. Expert commentary: Treatment to prevent AF recurrences is suboptimal, particularly in patients with persistent AF. Emerging technologies, such as documentation of atrial fibrosis using magnetic resonance imaging and documentation of electrical substrate using advanced electrocardiographic imaging techniques are likely to provide valuable insights about patient-specific tailoring of treatments.

Delayed Electroanatomic Mapping After Surgical Ablation for Persistent Atrial Fibrillation

BACKGROUND

Long-term efficacy of catheter-based treatment of persistent atrial fibrillation is unsatisfactory. Minimally invasive surgical ablation techniques have been developed recently but their true efficacy has never been systematically tested.

METHODS

Seventy patients (median age 63.5 years) with persistent atrial fibrillation underwent epicardial thoracoscopic radiofrequency pulmonary vein (PV) isolation, linear ablation, Marshal ligament disruption, and exclusion of the left atrial appendage. The procedure was followed by electroanatomic mapping 2 to 3 months later.

RESULTS

Only 76% of patients were in sinus rhythm at the beginning of electroanatomic mapping. Right PVs were found isolated in a higher proportion of patients compared with left PVs (75.7% versus 91.4%, p < 0.001). All four PVs and the left atrial posterior wall were isolated in 68.6% and 22.9% of patients, respectively. Most of the gaps around left PVs were localized in the superior and anterior quadrants, whereas in right PVs, the gaps were found predominantly on the roof and posterior wall. A typical site of reconduction on the inferior connecting line was the segment adjacent to the right inferior PV. No typical reconduction sites were found on the roof line, as 58.5% of patients required completion of the roof line along its full length.

CONCLUSIONS

Epicardial PV isolation was successful in the majority of patients, but was underwhelming with regard to isolation of the left PVs. Effective epicardially placed linear lines were rare. Our results highlight the significant limitations associated with a single-stage surgical approach and underline the necessity for a two-staged hybrid approach in the treatment of persistent atrial fibrillation.

The future of hybrid ablation: an emerging need for an anticoagulation protocol for thoracoscopic ablation

The midterm efficacy of hybrid ablation of atrial fibrillation (AF) reported in recent papers is about 70% in terms of sinus rhythm maintenance without antiarrhythmic drugs. Bearing in mind that the majority of patients enrolled are patients with persistent and long-standing persistent AF, the reported efficacies seem to be very good. Despite the high efficacies, safety remains a critical issue in hybrid, and especially thoracoscopic ablations. The frequency of complications during thoracoscopic ablations is more than 10% in the majority of reports. Most are short-term with no sequelae (such as pneumothorax or pneumonia); however, life-threatening complications have also been described, e.g., a sternotomy in response to a laceration of the left atrium (LA). One of the most serious ablation complications is stroke. The rate of strokes, which has been reported during or shortly after thoracoscopic ablation, seems to be higher than the rate reported after catheter ablation. This is especially true in papers describing thoracoscopic ablations that were not immediately followed by a catheter ablation. A possible explanation is differences in anticoagulation management during the two procedures. During catheter endocardial procedures, a standard anticoagulation protocol exists and is routinely applied; however, there is no such set of recommendations for anticoagulation during the thoracoscopic-phase of an ablation. It seems probable that, in many cases, no anticoagulation is used during thoracoscopic ablations. Moreover, whatever anticoagulation protocol is used during thoracoscopic ablations often goes unreported. A discussion about the best anticoagulation strategy during thoracoscopic ablation is urgently needed. In the future, standards of anticoagulation during thoracoscopic ablation should be clearly reported, just as they are now for catheter ablations.

Laparoscopic Repair of an Intrapericardial Diaphragmatic Hernia After Convergent Maze Procedure

The convergent maze procedure (CMP) is a new minimally invasive technique for the surgical treatment of atrial fibrillation (AF). Recently, multiple groups have published excellent results and few adverse events with CMP. However, we now report the second case of an intrapericardial diaphragmatic hernia with small bowel obstruction that resulted from CMP. This adverse event was managed successfully by laparoscopic repair of the hernia and the use of a polytetrafluoroethylene mesh closure with hepatic buttress, achieving an excellent result. With the expanding use of CMP for the treatment of AF, awareness of this adverse event and its appropriate management are increasingly important.