Left Atrial Appendage Exclusion Research Articles

Role of video-assisted thoracoscopy in the management of stroke

To evaluate the role of surgery (anterior thoracotomy versus video-assisted thoracoscopy) in avoidance of stroke by obliteration of the left atrial appendage in patients with chronic nonrheumatic atrial fibrillation. In a prospective study, 58 patients (35 men and 23 women, aged 62 ± 13.2 years) with chronic nonrheumatic atrial fibrillation were divided into 2 groups: group A was 29 patients who underwent an anterior thoracotomy, and group B was 29 patients who had video-assisted thoracoscopic obliteration of the left atrial appendage. All patients were followed up for at least 2 years. The 2 groups were well matched for age, sex, and comorbidities. No stroke was observed in either group. Operative time was significantly longer in group B. There was no intraoperative or postoperative complication, except for 2 cases of superficial wound infection in group A. In chronic atrial fibrillation, prophylactic left atrial appendage exclusion is suggested to prevent occurrence of stroke, which can be achieved by a surgical or thoracoscopic approach, but a video-assisted thoracoscopic approach is effective, less invasive, and avoids the complications of a surgical approach.

Pulmonary Artery Perforation by Plug Anchoring System After Percutaneous Closure of Left Appendage

Patients receiving oral anticoagulant therapy for atrial fibrillation who are at high risk of bleeding are increasingly referred for percutaneous left atrial appendage exclusion. Although effective, this procedure is not free from risk. We report a case of pericardial tamponade due to pulmonary artery tear caused by a trespassing anchoring hook of an AGA plug. Intraoperatively, no actual bleeding was found from the left appendage, a proof of its complete occlusion by the device. The patient underwent successful surgical repair and radio-frequency ablation of atrial fibrillation was performed by pulmonary veins encircling.

Stand Alone Surgical Ablation for Atrial Fibrillation

Trials to maintain sinus rhythm in patients with atrial fibrillation (AF) and refractory symptoms have been complicated by lack of success or intolerance of medications. Experience with minimally invasive AF surgery is relatively new, and early results have been promising. However, the study populations and techniques were heterogeneous, and the follow-up periods were short in many series. We present a single center experience through a retrospective review of medical records of patients who had minimally invasive AF surgery. The surgical techniques addressed several possible mechanisms of AF and causes of recurrence, including pulmonary vein isolation, underlying substrates modification, ligament of Marshall interruption, ganglion plexus ablation, and left atrial appendage exclusion. Thirty-three cases were identified. The mean duration of follow-up was 23.2 months, and 58.6% were maintained in a sinus rhythm and were off antiarrhythmic drugs at the end of the follow-up period. Cases with persistent AF had a lower success rate. Results with minimally invasive surgery are suboptimal at two years of follow-up, particularly for patients with persistent AF.

Surgical Strategies and Devices for Surgical Exclusion of the Left Atrial Appendage: A Word of Caution

In patients with chronic atrial fibrillation, 90% of clots are located in the left atrial appendage (LAA). Therefore, LAA exclusion is a means of preventing thrombus formation and subsequent thromboembolic events in these patients. The LAA can be excluded from the systemic circulation via surgical, percutaneous, or thoracoscopic approaches. The surgical aim is complete obliteration of the appendage without a significant increase in either postoperative complications (bleeding, arrhythmias) or recurrence. We discuss the current surgical techniques available for LAA obliteration and review their results.

Initial Experience With a Novel Percutaneous Left Atrial Appendage Exclusion Device in Patients With Atrial Fibrillation, Increased Stroke Risk, and Contraindications to Anticoagulation

Atrial fibrillation (AF) increases by fivefold a patient's risk for thromboembolic stroke. The main source of emboli in AF is the left atrial appendage (LAA). Therefore, LAA closure could reduce the risk for thromboembolic events in AF. The investigators report the first United States experience with a novel percutaneous LAA closure device, the Lariat snare device, and its outcomes in 21 patients with AF, CHADS2 scores ≥2, and contraindications to anticoagulation. The LAA was closed with a snare containing suture from within the pericardial space. The intraoperative success of the procedure was confirmed by left atrial angiography and transesophageal echocardiographic color Doppler flow. The effectiveness of the procedure was evaluated by follow-up transesophageal echocardiography. The incidence of periprocedural and short-term complications was assessed by reviewing medical records. Twenty patients (100%) had successful LAA exclusion that was preserved at 96 ± 77 days. No patient had a stroke during an average of 352 ± 143 days of follow-up. One patient had right ventricular perforation and tamponade that required surgical exploration and repair. Two patients required prolonged hospitalization: 1 because of pericardial effusion that required repeat pericardiocentesis and 1 because of noncardiac co-morbidities. Three patients developed pericarditis <1 month after the procedure, of whom 1had associated pericardial effusion that required drainage. In conclusion, percutaneous LAA exclusion can be achieved successfully and with an acceptable incidence of periprocedural and short-term complications. Further studies are needed to determine whether LAA exclusion lowers the long-term risk for thromboembolic events in patients with AF and contraindications to anticoagulation.

Abstract 19579: The Incidence of Stroke and Pericardial Effusion after Pericardial Suture Ligation of the Left Atrial Appendage

Introduction: Left atrial appendage closure (LAAC) is an effective alternative to warfarin in nonvalvular AF patients who are intolerant to oral anticoagulation. Our aim was to determine the incidence of stroke and pericardial effusion following pericardial suture ligation of the left atrial appendage. Methods: Retropspective analysis of 16 patients who underwent LAAC with an epicardial suture delivery system (LARIAT) at single center. Pericardial access was obtained using an anterior approach, followed by transeptal puncture. Epicardial and endovascular magnetic-tipped guidewires were then aligned, and the epicardial snare and suture were advanced over the left atrial appendage. After snare closure and suture deployment, TEE and fluoroscopy were used to confirm left atrial appendage exclusion. Patients were discharged on aspirin. Reported stroke or TIA events were confirmed by CT or MRI. Results: Of the 16 patients included, the mean age was 74.2 ±9.1, 56% of patients (9/16) were male, and the mean CHADS2 score was 3.6 ± 1.2; 11 patients (69%) had a prior stroke or TIA. These patients accumulated a total of 9.6 person-years of follow up (5.3 months ±7.7). LAAC was confirmed by repeat TEE at 1.95 ± 3.0 months, and 7/16 patients (44%, 95% CI 10-77%) experienced any size left atrial appendage leak, and 1/16 (6%, 95% CI 0-20%) experienced a large leak (≥3mm). After LAAC, 1/16 patients experienced a stroke. A 71 year old male (CHADS2 = 3) who was not on anticoagulation developed a central retinal artery occlusion 5 months post-procedure. The overall incidence of stroke or TIA was 6%, (95% CI 0-20%). After LAAC, 3/16 patients developed a pericardial effusion (19%, 95% CI 0-40%), of which 2 required pericardiocentesis. Conclusion: We observed a significant rate of pericardial effusion and symptomatic ischemic events after LAAC with an epicardial suture ligation system; further study is needed to assess its relative safety compared to alternate LAAC devices in patients intolerant to oral anticoagulation.

Percutaneous Left Atrial Appendage Exclusion Using the Lariat in Patients With Atrial Fibrillation: Initial Clinical Experience and Long-Term Results

A total of 119 patients between the ages of 35 to 81 years were evaluated by contrast 3-dimensional-computed tomography. Sixteen patients had left atrial appendage (LAA) width > 40 mm or morphology (8 patients with superior- posterior orientation of the LAA apex, commonly with the apex behind the pulmonary artery) contraindications. Of the remaining 103 patients, 11 patients were excluded because of an LAA thrombus on preprocedural TEE. Of the 92 patients who proceeded to LAA ligation, 3 patients were excluded because of pericardial adhesions precluding pericardial access. Acute LAA closure was achieved in 85 of 89 patients. TEE performed 1 day, 30 days, and 90 days after the procedure revealed complete closure in 95% of the patients in whom LAA ligation was attempted. One-year follow-up TEE results will be presented. There were 3 procedure-related complications (2 during pericardial access and 1 during transseptal catheterization). There were no device-related complications nor embolic strokes. One-year clinical follow-up will be presented.

Left Atrial Appendage Occlusion and Ligation Devices: What Is Available, How to Implement Them, and How to Manage and Avoid Complications

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide, and it is associated with an elevated risk of thromboembolic events, including ischemic stroke. Evidence suggests that at least 90% of left atrial thrombi discovered in patients with AF are localized to the left atrial appendage (LAA). Surgical ligation or excision of the LAA is considered the standard of care in patients who undergo mitral valve surgery or as an adjunct to a surgical Maze procedure for treatment of AF. In addition, in selected patients with AF and an elevated risk of thromboembolic events, particularly in those with contraindication to oral anticoagulation (OAC) therapy, it is reasonable to consider LAA exclusion to offer protection against ischemic stroke and other embolic complications. This can be achieved through a number of different strategies, including surgical amputation or ligation of the LAA, percutaneous endocardial occlusion of the LAA by deployment of occlusive devices, and also ligation of the LAA via a closed-chest, percutaneous, epicardial catheter-based approach in select patients. Although results from several recent percutaneous LAA closure and ligation studies are highly promising, the evidence for long-term efficacy and safety is insufficient to presently recommend this approach to all patients other than those in whom long-term OAC is contraindicated. Future randomized studies are required to further address the long-term safety and efficacy of these therapeutic options. Finally, the role for LAA occlusion and ligation seems less clear in patients who undergo successful catheter ablation of AF, since at least in a subgroup of these patients antiplatelet therapy alone has been shown to be sufficient.

Cierre percutáneo de la orejuela izquierda para prevención de tromboembolia en la fibrilación auricular

Background Embolic stroke is a major concern in atrial fibrillation (AF), and anticoagulation is the therapy of choice to prevent it. Around 20% of patients with AF have contraindications for anticoagulation (OAC). The left atrial appendage (LAA) has been identified as the most common place of thrombosis in patients with AF, particularly in those with non-valvular AF or impaired ventricular function. LAA occlusion reduces the incidence of embolic events in these patients. This article describes a case of percutaneous closure of LAA with the Amplatzer Cardiac Plug device. The patient was at high risk of embolism and had absolute contraindication for OAC. The procedure was performed at the cardiac catheterization laboratory under general anesthesia with fluoroscopic guidance and transesophageal echocardiography, and complete closure of the LAA was achieved. During the procedure, no complications were reported. The patient remained event-free at three-month follow-up, with complete exclusion of LAA. No embolic events have been reported.

Percutaneous closure of left atrial appendage to prevent thromboembolism in atrial fibrillation

Background Embolic stroke is a major concern in atrial fibrillation (AF), and anticoagulation is the therapy of choice to prevent it. Around 20% of patients with AF have contraindications for anticoagulation (OAC). The left atrial appendage (LAA) has been identified as the most common place of thrombosis in patients with AF, particularly in those with non- valvular AF or impaired ventricular function. LAA occlusion reduces the incidence of embolic events in these patients. This article describes a case of percutaneous closure of LAA with the Amplatzer Cardiac Plug device. The patient was at high risk of embolism and had absolute contraindication for OAC. The procedure was performed at the cardiac catheterization laboratory under general anesthesia with fluoroscopic guidance and transesophageal echocardiography, and complete closure of the LAA was achieved. During the procedure, no complications were reported. The patient remained event-free at three-month follow-up, with complete exclusion of LAA. No embolic events have been reported.

Epicardial left atrial appendage clip occlusion also provides the electrical isolation of the left atrial appendage

The exclusion of the left atrial appendage (LAA) has been used to reduce the risk of stroke associated with atrial fibrillation (AF). While LAA exclusion has been associated with a reduced risk of stroke, the effect on the electrical activity of the LAA (a potential source of AF) remains unknown. As such, we sought to demonstrate whether surgical epicardial clip occlusion leads to the electrical isolation of the LAA. From December 2010 until August 2011, 10 patients with paroxysmal AF underwent off-pump coronary artery bypass surgery with bilateral pulmonary vein isolation and an LAA clip occlusion with a new epicardial clip. Before and after the clip was placed, pacing manoeuvres were performed to assess the electrical exit and entry blocks from the LAA. All clips were applied successfully. The mean procedure time for the clip application was 4 ± 1 min. No complications occurred related to clip application. Prior to the pericardial closure, 18 ± 3 min after the clip placement, the LAA stimulation and pacing manoeuvres demonstrated complete electrical isolation of the LAA in all cases. Epicardial LAA clip occlusion leads to the acute electrical isolation of the LAA and may not only provide stroke prevention but also reduce the recurrence of AF.

Prospective Clinical Study of a Novel Left Atrial Appendage Occlusion Device

This Food and Drug Administration-approved investigational device exempt trial assessed the safety and efficacy of a novel device for external left atrial appendage (LAA) exclusion. Delivery tool and implant consisting of connectors imbedded in a compliant, soft silicone applied to the base of the LAA flush with the external wall was assessed. Patients in this prospective, multicenter trial were undergoing elective, nonendoscopic cardiac operations. A core laboratory independently assessed all intraprocedural and 90-day transesophageal echocardiograms. Sixty patients (37 men), aged 33 to 86 years, enrolled. The mean LAA application time was 27 seconds. Transesophageal echocardiograms at 90 days were available in 54 patients, and no leaks were detected. The residual LAA cavity exceeded 6 mm in 5 patients. One delivery device failed to close, and an adjunctive suture was required to complete LAA exclusion. One patient required adjunct sutures at a small tear site related to manual manipulation after fastener application. The study demonstrated safety and efficacy of this LAA exclusion device, offering an alternative to manual suturing or staples with or without reinforcement.

Left Atrial Appendage Occlusion Pilot Study of a Fourth-Generation, Minimally Invasive Device

Exclusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The aim of this study was to evaluate the feasibility and efficacy of a fourth-generation atrial exclusion device developed for minimally invasive applications. The novel atrial exclusion device consists of two polymer beams and two elastomeric bands that connect the two beams at either end. Fifteen mongrel dogs were implanted with the device at the base of the left atrial appendage through a median sternotomy and were evaluated at 30 (n = 7), 90 (n = 6), and 180 (n = 2) days after implantation by epicardial echocardiography, left atrial and coronary angiography, gross pathology, and histology. Left atrial appendage exclusion was completed without hemodynamic instability. Coronary angiography revealed that the left circumflex artery was patent in all cases. A new endothelial tissue layer developed, as expected, on the occluded orifice of the left atrium. This novel atrial exclusion device achieved easy, reliable, and safe exclusion of the left atrial appendage, with favorable histological results in a canine model for up to 6 months. Clinical application could provide a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

Left atrial appendage ligation with single transthoracic port assistance: a study of survival assessment in a porcine model (with videos)

Left atrial appendage (LAA) exclusion is a well-known procedure for the prevention of stroke in high-risk patients with atrial fibrillation and contraindication to long-term oral anticoagulant therapy. To evaluate a natural orifice transluminal endoscopic surgery (NOTES) approach for LAA ligation. In 4 acute and 6 survival pigs, we performed LAA by using a forward-viewing, single-channel gastroscope and an operative thoracoscope with a 3-mm working channel (introduced through an 8-mm single transthoracic port). Animal laboratory. The gastroscope was introduced in the thoracic cavity through an esophageal submucosal tunnel. An end loop introduced through the gastroscope was used to legate the LAA. In the survival experiments, the esophageal mucosa was closed using hemoclips. The time, safety, and feasibility of the procedure were recorded. In the survival experiments, endoscopy and postmortem examination were performed on postoperative day 14. Creation of a submucosal tunnel and esophagotomy were safely performed in all animals without incidents. The mean time for esophagotomy was 17.0 ± 6.3 minutes. Pericardial dissection and LAA ligation were performed in all animals but 1. The mean time for LAA ligation was 34.4 ± 19.1 minutes. No adverse events occurred during the survival period. Endoscopy showed complete esophageal closure. Postmortem examination revealed pleural adhesions on the site of pericardial dissection, and the LAA was fibrotic with the endoloop in place. Animal study. LAA ligation with single transthoracic trocar assistance is feasible and may be an alternative to anticoagulant therapy or to permanent intracardiac implants in patients with atrial fibrillation.

Left Atrial Appendage Exclusion for Stroke Prevention in Atrial Fibrillation

The public health burden of atrial fibrillation (AF) and associated thromboembolic stroke continues to grow at alarming rates. AF leads to a fivefold increase in the risk of stroke. Therefore, stroke prevention remains the most critical aspect of AF management. Current standard of care focuses on oral systemic anticoagulation, most commonly with warfarin and now with newer agents such as dabigatran, rivaroxaban, and apixaban. However, the challenges and limitations of oral anticoagulation have been well documented. Given the critical role of the left atrial appendage (LAA) in the genesis of AF-related thromboembolism, recent efforts have targeted removal or occlusion of the LAA as an alternative strategy for stroke prevention, particularly in patients deemed unsuitable for oral anticoagulation. This paper highlights recent advances in mechanical exclusion of the LAA. The problem of AF and stroke is briefly summarized, followed by an explanation for the rationale behind LAA exclusion for stroke prevention. After briefly reviewing the history of LAA exclusion, we highlight the most promising LAA exclusion devices currently available. Finally, we discuss future challenges and opportunities in this growing field.

Excision or exclusion of left atrial appendage?

Stroke is one of the leading causes of mortality and morbidity today. In the majority of the cases, stroke results from cardiac emboli predominantly in patients with atrial fibrillation. Theoretically, the most likely site for generation of thrombus formations as a prerequisite for emboli and stroke is the left atrial appendage (LAA). Here, the three characteristics of Virchow's triad are realized, especially flow abnormalities, besides those of the vessel wall and constituents in blood [1]. Therefore, it makes theoretical sense to exclude the LAA in order to prevent stroke as recommended in the ACC/AHA Guidelines [2] during mitral valve surgery and MAZE procedures, although some authors argue that LAA exclusion is not the whole story [3] of stroke prevention and that strokes occur also after LAA occlusion, related to unsuccessful exclusion [4] or other sources. In this issue, Hernandez-Estefania report on a special technique for LAA occlusion including invagination and double-suture technique [5]. A purse-string suture is used to delineate the rim of the orifice which is facilitated by the invagination of the LAA. Although this might help to better define the borders of the os of the LAA, a clearly defined ridge is not present at the anterior and inferior borders of the LAA os [6]. Furthermore, the rim of the os is smooth [6]. Thus, there may be few firm tissues to anchor securely the sutures for occlusion. In addition, the oval area of the os is tugged together by the sutures, potentially creating tension forces in the tissue tending to reset the oval shape of the os. These are the factors that might cause some kind of re-opening of the LAA orifice years after the operation [4]. Whether this occurs with the proposed LAA occlusion technique remains to be seen. Therefore, long-term follow-up is needed to decide whether this is an effective technique for LAA occlusion. A more definite approach would be the complete excision of the LAA. Since our negative results years after direct suture closure of the LAA [7], we switched our technique to complete excision of LAA. The LAA atriotomy is closed between two 4–5 mm wide strips of Teflon felt to reinforce the fragile tissue, using a mattress suture followed by a continuous over and over suture to definitely close the resection line. The excision technique was reported to yield the most successful results compared with exclusion by suture or stapling [4]. In that report, 27% of patients in the excision group showed a residual stump of >1 cm, but the author did not find thrombus material in the residual stump at follow-up investigation, indicating that this residual stump at the base may not generate thrombus formation. Taken together, it would be appropriate for the proposed occlusion technique to stand the test of time for final judgment of its effectiveness. The most successful technique still remains the excision of the LAA.

Navigating the mini-maze: Systematic review of the first results and progress of minimally-invasive surgery in the treatment of atrial fibrillation

BackgroundIn this paper we present a systematic literature overview and analysis of the first results and progress made with minimally-invasive surgery using RF energy in the treatment of AF. The minimally-invasive treatment for atrial fibrillation (AF) tries to combine the success rate of surgical treatment with a less invasive approach to surgery. It has the additional potential advantage of ganglion plexus (GP) ablation and left atrial appendage exclusion. Furthermore, additional left atrial ablation lines (ALAL) can be created in non-paroxysmal AF patients. MethodsFor the search query multiple databases were used. Exclusion and inclusion criteria were applied to select the publications to be screened. All remaining articles were critically appraised and only relevant and valid articles were included in our results. ResultsTwenty-three studies were included. In 15 studies GPs around the pulmonary veins were ablated. In four studies ALAL were performed. Single procedure success rate was 69% (95% CI, range 58%–78%) without antiarrhythmic drugs (AAD) and 79% (95% CI, range 71%–85%) with AAD at one year follow-up. Mortality was 0.4%, and various complications were reported (3.2% surgical, 3.2% post-surgical, 2.6% cardiac, 2.1% pulmonary, 1.7% other). ConclusionsTwenty-three studies of minimally-invasive surgery for AF have been reviewed with success rates between that of the standard maze procedure and catheter ablation. These first combined results show promise; however, minimally-invasive surgery is still evolving, for instance by the recent inclusion of electrophysiological endpoints. Furthermore, the type of ALAL and the additional value of GP ablation have to be elucidated.

POSTER PRESENTATIONS

POSTER PRESENTATIONS

Wolf minimaze operation plus endocardial catheter ablation cured chronic atrial fibrillation (one case report)

Case historyThis is a 61-year-old male patient. He had paroxysmal atrial fibrillation (AF) for about 14 years, refractory to propafanone and amiodarone. AF had persisted for 2 years before Wolf...

Incomplete occlusion of the left atrial appendage with the percutaneous left atrial appendage transcatheter occlusion device is not associated with increased risk of stroke

Percutaneous approaches to left atrial appendage (LAA) closure are being developed for stroke prophylaxis in atrial fibrillation patients as an alternative to warfarin. Non-randomized clinical trials suggested that the first of these devices, the percutaneous left atrial appendage transcatheter occlusion (PLAATO) device, is safe and reduces stroke risk. Percutaneous closure has the potential limitation of incomplete exclusion of LAA from the systemic circulation, which could potentially lead to thrombus formation and stroke. This study investigated the interaction between residual blood flow in the LAA after percutaneous closure with PLAATO and risk of stroke. Data from the PLAATO trial current as of July 2010 was used for this analysis (n = 22). Mechanical occlusion using the PLAATO device was used in 22 patients (age 68 ± 5, CHADS(2) score = 3.03 ± 0.6). Warfarin and clopidogrel were stopped during follow-up in all but one patient due to development of pulmonary emboli. After an average follow-up of 58 ± 9 months, four out of 22 patients (16.7%) developed a new ischemic stroke/TIA, translating to an annualized embolic rate of 3.63%. There were no differences in the demographics (age, sex, and CHADS(2) score) among patients with and without stroke. Cardiac CT documented peri-device leak in three out of four patients with stroke and in seven out of nine (75% vs. 77%, p = 0.706) patients without stroke that agreed to have a follow-up cardiac CT (Chi squared with Yates correction for this interaction = 0.012, p = 0.912). TEE corroborated these results but failed to identify peri-device leak in three patients without stroke. The main finding of our analysis suggests that in long-term follow-up, residual flow after LAA occlusion with the PLAATO device, as documented by cardiac CT, is ubiquitous but is not associated with an increased risk of stroke.