Incidence and characteristics of left atrial appendage stumps after device-enabled epicardial closure

A Comparative Study of Thoracoscopic Left Atrial Appendage Clipping vs Stapled Resection

BACKGROUND

The left atrial appendage (LAA) is the predominant site of thrombus formation in atrial fibrillation (AF), which is associated with ischemic stroke. This study comparatively evaluated the complete LAA closure rates between LAA clipping and stapled resections.

METHODS

The study included 333 patients who underwent thoracoscopic operation with both preoperative and postoperative computed tomographic scans. Propensity score matching (4:1 ratio) was applied, matching 90 LAA clipping patients with 206 stapled resection patients. The primary end point was complete LAA closure, defined as a residual LAA depth of <1 cm on computed tomographic images obtained 1 year postoperatively.

RESULTS

No 30-day death was observed. Complete LAA closure was achieved in 85.9% (286 of 333) of patients. After propensity score matching, the clipping group demonstrated a significantly higher complete LAA closure rate than the stapled resection group (95.6% vs 83.0%, P = .003). The residual LAA stump depth was also shorter in the clipping group compared with the stapled resection group (2.9 vs 5.3 mm, P = .001). Two patients with a residual LAA stump exhibited an association with ischemic stroke during follow-up.

CONCLUSIONS

The clipping group demonstrated a higher rate of complete LAA closure compared with the stapled resection group. Close monitoring of patients with residual LAA stumps is essential. Further research with larger cohorts is needed to elucidate impact of the residual LAA stump on thromboembolic events.

The left atrial appendage closure by surgery-2 (LAACS-2) trial protocol rationale and design of a randomized multicenter trial investigating if left atrial appendage closure prevents stroke in patients undergoing open-heart surgery irrespective of preoperative atrial fibrillation status and stroke risk

BACKGROUND

Current recommendations regarding the use of surgical left atrial appendage (LAA) closure to prevent thromboembolisms lack high-level evidence. Patients undergoing open-heart surgery often have several cardiovascular risk factors and a high occurrence of postoperative atrial fibrillation (AF)-with a high recurrence rate-and are thus at a high risk of stroke. Therefore, we hypothesized that concomitant LAA closure during open-heart surgery will reduce mid-term risk of stroke independently of preoperative AF status and CHA2DS2-VASc score.

METHODS

This protocol describes a randomized multicenter trial. Consecutive participants ≥18 years scheduled for first-time planned open-heart surgery from cardiac surgery centers in Denmark, Spain, and Sweden are included. Both patients with a previous diagnosis of paroxysmal or chronic AF, as well as those without AF, are eligible to participate, irrespective of their CHA2DS2-VASc score. Patients already planned for ablation or LAA closure during surgery, with current endocarditis, or where follow-up is not possible are considered noneligible. Patients are stratified by site, surgery type, and preoperative or planned oral anticoagulation treatment. Subsequently, patients are randomized 1:1 to either concomitant LAA closure or standard care (ie, open LAA). The primary outcome is stroke, including transient ischemic attack, as assigned by 2 independent neurologists blinded to the treatment allocation. To recognize a 60% relative risk reduction of the primary outcome with LAA closure, 1,500 patients are randomized and followed for 2 years (significance level of 0.05 and power of 90%).

CONCLUSIONS

The LAACS-2 trial is likely to impact the LAA closure approach in most patients undergoing open-heart surgery.

TRIAL REGISTRATION

NCT03724318.

Long-Term Imaging and Clinical Outcomes of Surgical Left Atrial Appendage Occlusion With AtriClip

Surgical left atrial appendage (LAA) occlusion with an AtriClip (AtriCure, West Chester, Ohio) is frequently performed for stroke prophylaxis in patients with atrial fibrillation (AF). We conducted a retrospective analysis of all patients with long-standing persistent AF who underwent hybrid convergent ablation and LAA clipping. Contrast-enhanced cardiac computed tomography was performed at 3 to 6 months after LAA clipping to assess the degree of complete closure and the residual LAA stump. A total of 78 patients (64 ± 10 years, 72% male) underwent LAA clipping as part of hybrid convergent AF ablation, from 2019 to 2020. Median size of AtriClip used was 45 mm. Mean LA size was 4.6 ± 1 cm. At 3-to-6 months follow-up computed tomography, 46.2% of patients (n = 36) had a residual stump proximal to the deployed LAA clip. Mean depth of residual stump was 3.95 ± 5.5 mm, with 19% of patients (n = 15) having a stump depth of ≥10 mm and 1 patient requiring more endocardial LAA closure owing to large stump depth. During 1-year follow-up, 3 patients developed stroke; device leak of 6 mm was noted in 1 patient; and none of the patients had a thrombus proximal to the clip. In conclusion, high incidence of residual LAA stump was observed with AtriClip. Larger studies with long-term follow-up are needed to better assess the thromboembolic implications of a residual stump after AtriClip placement.

The Strengths and Weaknesses of Left Atrial Appendage Ligation or Exclusion (LARIAT, AtriaClip, Surgical Suture)

Left atrial appendage (LAA) epicardial exclusion has been associated with addressing 2 potential deleterious consequences attributed to the LAA, namely, thrombus formation and an arrhythmogenic contributor in advanced forms of atrial fibrillation. With more than 60 years of history, the surgical exclusion of the LAA has been firmly established. Numerous approaches have been used for surgical LAA exclusion including surgical resections, suture ligation, cutting and non-cutting staples, and surgical clips. Additionally, a percutaneous epicardial LAA ligation approach has been developed. A discussion of the various epicardial LAA exclusion approaches and their efficacy will be discussed, along with the salient beneficial affects on LAA thrombus formation, LAA electrical isolation and neuroendocrine homeostasis.

Is it feasible to measure pulmonary vein data using volume rendering images?

BACKGROUND

Pulmonary vein (PV) data are commonly measured on multiplanar image reformation (MPR) images and volume rendering (VR) images.

PURPOSE

To compared and analyze the advantages and disadvantages of PV data based on VR images and MPR images.

MATERIAL AND METHODS

A total of 94 patients with atrial fibrillation (AF) with imaging data were included in the study. The respective image postprocessing time and the three surgical interventionists' preferences for the two images were recorded. A paired t-test or chi-square test was used to compare their difference, and P < 0.05 was considered statistically significant.

RESULTS

There was no statistically significant difference between the data values including the maximal and minimal ostial diameters of the left superior PV (LSPV), the left inferior PV (LIPV), the right superior PV (RSPV), and the right inferior PV (RIPV) obtained by VR and MPR images (P > 0.05). Yet, the mean postprocessing time of VR images (15.10 ± 3.05 min) was shorter compared to MPR images (16.54 ± 2.60 min) (t = 22.84, P < 0.05). All three surgical interventionists preferred VR images (accounted for 85.1%, 86.2%, and 84.0%, respectively), and there was no statistical difference in the degree of image preference among the three (chi-square = 0.596, P = 0.963).

CONCLUSION

PV data measurement could be performed on both VR and MRP images; however, the data on VR images were more intuitive and more accessible for interventional surgeons.

The role of cardiac imaging before and after left atrial appendage standalone thoracoscopic exclusion

AIMS

To assess the characteristics of left atrial appendage (LAA) stump and left atrial (LA) volume after standalone totally thoracoscopic LAA exclusion in 40 patients with nonvalvular atrial fibrillation (NVAF) and contraindications to oral anticoagulation (OAC), using cardiac computed tomography (CCT) and transoesophageal echocardiography (TOE).

METHODS

Using CCT and TOE, we evaluated correct AtriClip Pro II positioning, the presence and characteristics of the LAA stump and the postprocedural LA volume, at 3 months' follow-up. Stump depth was measured with both CCT and TOE using a new method, based on left circumflex artery (LCX) course.

RESULTS

After placement of AtriClip, all 40 patients discontinued OAC, and no stroke occurred. LAA exclusion was achieved in 40/40 patients at 3 months' follow-up. LAA stump (depth <10 mm in 12/18 stump, 67%) was observed in 18 patients. The overall (LA + LAA) volume and isolated LA volume were statistically different when comparing cases with and without LAA stump (P < 0.02). LAA ostium dimensions (perimeter and area) and LAA volume correlate with stump depth (P < 0.02). There was a high correlation between CCT and TOE in stump identification and depth measurement (P < 0.02). Compared with the baseline, CCT LA volume increased (P < 0.01) at 3 months' follow-up.

CONCLUSION

Preprocedural and postprocedural CCT and TOE are useful and comparable in patients undergoing standalone totally thoracoscopic exclusion of LAA, because these imaging methods can identify anatomical LAA and LA characteristics predisposing for a postprocedural residual stump.

Heart Team for Left Appendage Occlusion without the Use of Antithrombotic Therapy: The Epicardial Perspective

BACKGROUND

Left atrial appendage occlusion is an increasingly proposed treatment for patients with atrial fibrillation and poor tolerance to anticoagulants. All endovascular devices require antithrombotic therapy. Anatomical and clinical variables predisposing to device-related thrombosis, as well as post-procedural peri-device leaks, could mandate the continuation or reintroduction of aggressive antithrombotic treatment. Because of the absence of foreign material inside the heart, epicardial appendage closure possibly does not necessitate antithrombotic therapy, but data of large series are missing.

METHODS

Multidisciplinary team evaluation for standalone totally thoracoscopic epicardial appendage closure was done in 180 consecutive patients with atrial fibrillation and poor tolerance to antithrombotic therapy. One hundred and fifty-two patients consented (male 66.1%, mean age 76.1 ± 7.4, CHA2DS2VASc mean 5.3 ± 1.6, HASBLED mean 3.8 ± 1.1). Indications were cerebral hemorrhage (48%), gastro-intestinal bleeding (33.3%), and other bleeding (20.7%). No antithrombotic therapy was prescribed from the day of surgery to the latest follow up.

RESULTS

Procedural success was 98.7%. At a mean follow up of 38.2 ± 18.8 months, cardioembolic and bleeding events were 1.3% and 0.6%, respectively. Among patients with a history of blood transfusions (41.1%), none needed further transfusions or treatment post procedure.

CONCLUSION

Epicardial appendage occlusion without any antithrombotic therapy appears to be safe and effective. This strategy could be advised when minimization of bleeding risk concomitant to stroke prevention is needed.

Mitral valvuloplasty with left atrial appendage closure and pacemaker implantation in a dog with severe myxomatous mitral valve degeneration: a case report

Background

Mitral valvuloplasty (MVP) has been widely recognized as a treatment option for myxomatous mitral valve disease (MMVD). However, postoperative complications such as thromboembolism, arrhythmia, and pancreatitis in some cases have resulted in death. We treated a dog with severe MMVD complicated by impaired sinus function with MVP and pacemaker implantation. Also, due to an intrinsic procoagulant state and severe arrhythmia after the MVP, left atrial appendage (LAA) closure was performed to reduce the postoperative risk of thrombosis.

Case presentation

An 11-year-old castrated 7.5-kg male Miniature Schnauzer with a history of congestive heart failure was brought to Shiraishi Animal Hospital for MMVD surgical treatment. Echocardiography revealed an enlarged left atrium and ventricle secondary to MMVD. Sinus arrest with 2 to 3-second periods of asystole was identified by electrocardiogram. Mitral valvuloplasty was performed with cardiopulmonary bypass to treat the MMVD. After coronary reperfusion, there was no spontaneous electrical activity. Cardiac arrest continued. Based on this surgical outcome, a permanent pacemaker was implanted. In addition, LAA closure with an AtriClip was performed to prevent intra-atrial thrombus formation. Cardiac remodeling and congestion were ameliorated after surgery. Sinus rhythm was restored 5 days postoperatively; however, the patient continued pacemaker dependent. All cardiac drugs were discontinued 3 months after surgery. The owner reported no postoperative complications (i.e., thrombosis), and the patient was brought for a check-up 4 months after the operation in good health.

Conclusions

For surgical MMVD cases complicated with impaired sinus function, the chances of spontaneous sinus rhythm are low, requiring pacemaker implantation. LAA closure may be considered to protect against decreased atrial function after mitral valvuloplasty and prevent intra-atrial thrombus formation.

The Strengths and Weaknesses of Left Atrial Appendage Ligation or Exclusion (LARIAT, AtriaClip, Surgical Suture)

Left atrial appendage (LAA) epicardial exclusion has been associated with addressing 2 potential deleterious consequences attributed to the LAA, namely, thrombus formation and an arrhythmogenic contributor in advanced forms of atrial fibrillation. With more than 60 years of history, the surgical exclusion of the LAA has been firmly established. Numerous approaches have been used for surgical LAA exclusion including surgical resections, suture ligation, cutting and non-cutting staples, and surgical clips. Additionally, a percutaneous epicardial LAA ligation approach has been developed. A discussion of the various epicardial LAA exclusion approaches and their efficacy will be discussed, along with the salient beneficial affects on LAA thrombus formation, LAA electrical isolation and neuroendocrine homeostasis.

Standalone epicardial left atrial appendage exclusion for thromboembolism prevention in atrial fibrillation

OBJECTIVES

Most strokes associated with atrial fibrillation (AF) result from left atrial appendage thrombi. Oral anticoagulation can reduce stroke risk but is limited by complication risk and non-compliance. Left atrial appendage exclusion (LAAE) is a new surgical option to reduce stroke risk in AF. The study objective was to evaluate the safety and feasibility of standalone thoracoscopic LAAE in high stroke risk AF patients.

METHODS

This was a retrospective, multicentre study of high stroke risk AF patients who had oral anticoagulation contraindications and were not candidates for ablation nor other cardiac surgery. Standalone thoracoscopic LAAE was performed using 3 unilateral ports access and epicardial clip. Periprocedural adverse events, long-term observational clinical outcomes and stroke rate were evaluated.

RESULTS

Procedural success was 99.4% (174/175 patients). Pleural effusion occurred in 4 (2.3%) patients; other periprocedural complications were <1% each. One perioperative haemorrhagic stroke occurred (0.6%). No phrenic nerve palsy or cardiac tamponade occurred. Predicted annual ischaemic stroke rate of 4.8/100 patient-years (based on median CHA2DS2-VASc score of 4.0) was significantly higher than stroke risk observed in follow-up after LAAE. No ischaemic strokes occurred (median follow-up: 12.5 months), resulting in observed rate of 0 (95% CI 0-2.0)/100 patient-years (P < 0.001 versus predicted). Six all-cause (non-device-related) deaths occurred during follow-up.

CONCLUSIONS

Study proved that a new surgical option, standalone thoracoscopic LAAE, is feasible and safe. With this method, long-term stroke rate may be reduced compared to predicted for high-risk AF population.

Robotics-assisted epicardial left atrial appendage clip exclusion

Objectives

We demonstrate the feasibility and safety of robotics-assisted left atrial appendage clip exclusion in clinical practice.

Methods

Analysis of a single center robotics-assisted left atrial appendage clip exclusion experience using an epicardial linear clip device in patients with atrial fibrillation with high-risk of thromboembolic stroke and intolerance to oral anticoagulants.

Results

During the period from December 2017 to September 2020, we performed 42 robotics-assisted left atrial appendage clip exclusions in response to increased risk of bleeding in patients with atrial fibrillation and intolerance to oral anticoagulants. The average congestive heart failure, hypertension, age, diabetes, stroke, and vascular disease score was 5.2 ± 1.6 and hypertension, abnormal liver or kidney function, stroke, bleeding, labile international normalized ratio, elderly, drugs (aspirin, other antiplatelets, or anticoagulants) score was 4.5 ± 0.9. No patients died intraoperatively or within 30 days, or due to conversion to thoracotomy, intraoperative complications, or failure to apply the clip satisfactorily. The procedure was successfully completed despite pericardial adhesions in 2 patients with prior coronary bypass grafts and 3 with postpericarditis scars. Intraoperative transesophageal echocardiography was performed in 38 out of 42 patients; satisfactory exclusion with left atrial appendage stump <5 mm was confirmed in all. Average length of stay was 3.4 ± 3 days with 12 out of 42 patients discharged within 24 hours. Oral anticoagulants were discontinued in 41 out of 42 patients and no cases of 30-day stroke, myocardial ischemia, or new arrhythmias were observed. One case of hemothorax required thoracoscopy a day later. There was no reported thromboembolic stroke or transient ischemic attack at 12 months. One case of late lacunar stroke was due to in situ small intracranial vessel thrombosis without left atrial appendage thrombus on imaging.

Conclusions

Robotics-assisted left atrial appendage clip exclusion is a safe and feasible minimally invasive method for left atrial appendage management in patients with atrial fibrillation with intolerance to oral anticoagulants and increased risk of thromboembolic stroke.

The Convergent Atrial Fibrillation Ablation Procedure: Evolution of a Multidisciplinary Approach to Atrial Fibrillation Management

The treatment of AF has evolved over the past decade with increasing use of catheter ablation in patients refractory to medical therapy. While pulmonary vein isolation using endocardial catheter ablation has been successful in paroxysmal AF, the results have been more controversial in patients with long-standing persistent AF where extrapulmonary venous foci are increasingly recognised in the initiation and maintenance of AF. Hybrid ablation is the integration of minimally invasive epicardial ablation with endocardial catheter ablation, and has been increasingly used in this population with better results. The aim of this article was to analyse and discuss the evidence for the integration of catheter and minimally invasive surgical approaches to treat AF with specific focus on convergent ablation and exclusion of the left atrial appendage using a surgically applied clip.

Percutaneous approaches for retrieval of an embolized or malpositioned left atrial appendage closure device: A multicenter experience

BACKGROUND

Experience with retrieval of a Watchman left atrial (LA) appendage (LAA) closure device (WD) is limited. An embolized or grossly malpositioned WD warrants retrieval to minimize the risk of thromboembolic complications and vascular occlusion.

OBJECTIVE

The purpose of this study was to report approaches for percutaneous retrieval of a WD from multicenter experience.

METHODS

Data on successful WD retrievals were obtained from high-volume operators. Data included clinical characteristics; structural characteristics of the LA and LAA; and procedural details of the deployment and retrieval procedure, type of retrieval (immediate: during the same procedure; delayed: during a separate procedure after the successful deployment), equipment used, complications, and postretrieval management.

RESULTS

Ten successful percutaneous and 1 surgical retrievals comprised this study. Seven patients had immediate retrieval, while 4 had delayed retrieval. The median duration before delayed retrieval was 45 days (range 1-45 days). The median LAA diameter and size of a successfully deployed WD was 16 mm (range 14-24 mm) and 21 mm (range 21-30 mm), respectively. A WD was retrieved from the LA (n = 1), LAA (n = 2), left ventricle (n = 2), and aorta (n = 6). The reason for retrieval from the LAA was inadequate deployment, resulting in a significant peri-device leak. Retrieval from the LA or LAA was successfully performed using snares (n = 2) and a Raptor grasping device (n = 1). Retrieval from the left ventricle was achieved with a snare (n = 1) and surgery (n = 1). Retrieval from the aorta required snares (n = 5) and retrieval forceps (n = 1). Five patients were successfully reimplanted with a larger size WD. The only complication during percutaneous retrieval was a pseudoaneurysm.

CONCLUSION

Retrieval of an embolized or malpositioned WD is feasible, and familiarity with snares and grasping tools can facilitate a successful removal.

Epicardial left atrial appendage occlusion with a new medical device: assessment of procedural feasibility, safety and efficacy in a large animal model

Background

Left atrial appendage occlusion (LAAO) represents a treatment alternative to anticoagulation in patients with atrial fibrillation. We evaluate a novel device for epicardial LAAO in a translational canine model.

Methods

Nine hounds (n = 9) were used to assess usability, safety, and efficacy of the TigerPaw Pro (TPP) device for epicardial LAAO. Following baseline imaging (intra-cardiac echocardiography (ICE) and angiography) and intraoperative visual inspection, usability was tested via a ``closure/re-opening`` maneuver followed by deployment of a total of twenty TPP devices (n = 20) on the left and right atrial appendages respectively. Procedural safety was evaluated by assessing for adverse-events via direct Epicardial inspection and endocardial imaging. Efficacy evaluation included assessment of device positioning, presence of residual stumps and completeness of closure. Post-mortem evaluation was performed to confirm safety and efficacy.

Results

Usability testing of all TPP devices was successful (n = 20;100%, delivery-time range 22–120 s) without any procedural adverse-events (tissue damage or tears, bleeding, vessel-impingement, structural impact). All devices fully traversed the ostium (n = 18) or appendage body (n = 2), and conformed smoothly to adjacent cardiac anatomy. In nineteen deployments (n = 19;95%), all device connector pairs were fully engaged, while in one TPP device the most distal pair remained unengaged. ICE and post-mortem inspections revealed complete closure of all appendage ostia (n = 18;100%) and only in one case a small residual stump was detected. Intraoperative safety findings were further confirmed post-mortem. Devices created a nearly smooth line of closure via symmetric endocardial tissue-coaptation.

Conclusions

In this preclinical model, the TPP demonstrated good ease of use for ostial access, ability to re-position (after engagement) and rapid deployment, while achieving safe and effective LAAO.

Cardiac anatomy pertinent to the catheter and surgical treatment of atrial fibrillation

In the 1980s when surgery was first introduced for the treatment of atrial fibrillation (AF), one would often hear comments like "Every little old grandmother has AF. Why on earth would you operate on someone like that?".