Left Atrial Appendage Closure: Prevention and Management of Periprocedural and Postprocedural Complications

Incidence, risk factors, and outcomes of chylothorax after cardiac procedure in the United States

Background

To examine the epidemiology and risk factors of chylothorax after cardiac procedure in the United States using a contemporary nationally representative database.

Methods

We identified postoperative chylothorax events through National Inpatient Sample database (2016-2019) and compared baseline demographics, comorbidities, and in-hospital outcomes between hospitalizations with and without postoperative chylothorax. The Cochrane-Armitage test was used to analyze trends in incidence rates. Multivariable Poisson regression models were used to identify potential risk factors for postoperative chylothorax after cardiac procedure.

Results

A total of 819 (0.24%) admissions were associated with postoperative chylothorax. The crude and standardized incidence rates of chylothorax were 23.7 (95%CI, 22.1-25.4) and 61.5 per 10,000 cardiac procedure-related admissions, respectively, with no significant temporal change in incidence rate over the study period (Ptrend = 0.5249). Infants [adjusted rate ratio (aRR), 117.3, 95% confidence interval (CI), 94.5-145.5] and children (aRR, 60.2, 95%CI, 48.0-75.5) were more likely to develop chylothorax compared to adults. Heart and great vessel procedures (aRR, 4.36, 95%CI, 3.61-5.26), septal repair (aRR, 1.91, 95%CI, 1.58-2.29), heart transplant (aRR, 5.68, 95%CI, 4.55-7.10) and pericardial procedures (aRR, 4.04, 95%CI, 3.32-4.91) were associated with elevated risk for chylothorax. Admissions with chylothorax were associated with higher inpatient mortality (4.9% vs. 3.0%, p<0.0001), longer inpatient stay, higher costs and greater perioperative complication burden.

Conclusions

Following cardiac procedures, chylothorax is an uncommon but serious complication that affects the prognosis. The analysis reveals varying incidence rates across age groups and specific surgical procedures, with infants at elevated risk.

Use of Computed Tomography for Left Atrial Appendage Occlusion Procedure Planning and Post-Procedure Assessment

Transcatheter left atrial appendage occlusion (LAAO) is an alternative to systemic anticoagulation in patients with non-valvular atrial fibrillation with increased risk for thromboembolic events. Pre- and post-procedural imaging is essential for technical success, allowing practitioners to identify contraindications, select appropriate devices, and recognize procedural complications. Although transesophageal echocardiography has traditionally served as the preeminent imaging modality in LAAO, cardiac computed tomography imaging has emerged as a noninvasive surrogate given its excellent isotropic spatial resolution, multiplanar reconstruction capability, rapid temporal resolution, and large field of view.

Pericardial Effusion During the Perioperative Period for Left Atrial Appendage Closure

Objectives: To analyze the predictors of pericardial effusion (PE) during the perioperative period of the left atrial appendage closure procedure in our center. Methods: A total of 624 consecutive patients with non-valvular AF undergoing LAAC from May 2014 to October 2019 were involved in this study. Patients were divided into groups depending on whether they showed no PE, intraoperative PE or postoperative PE. We analyzed the predictors of PE during the perioperative period of the LAAC procedure. Results: (1) Of the 624 patients in our population (age 68.2 ± 9.1 years, 63% male, CHA2DS2-VASc score 3.4 ± 1.6), 30 patients experienced PE in the perioperative period, including 10 intraoperative PE and 20 postoperative PE. (2) A total of 26 (86.6%) patients had mild PE. 4 (13.4%) patients had pericardial tamponade, 2 (6.7%) of which were intraoperative, and the other 2 (6.7%) postoperative. (3) Significant differences were measured in relation to female sex, intraoperative time, combined procedures, changes in sinus rhythm, device retrieval times and duration of hospitalization between 2 groups (no PE occurred, intraoperative PE), P values were 0.039, 0.024, 0.004, 0.015, 0.003 and 0.039. Conclusions: Female sex, paroxysmal AF, changing in sinus rhythm, device retrieval times and intraoperative time all had a positive association with PE during the perioperative period.

Current practice and future prospects in left atrial appendage occlusion

The thromboembolic complications of Atrial fibrillation (AF) remain a major problem in contemporary clinical practice. Despite advances and developments in anticoagulation strategies, therapy is complicated by the high risk of bleeding complications and need for meticulous medication compliance. Over the past few decades, the left atrial appendage has emerged as a promising therapeutic target to prevent thromboembolic events while mitigating bleeding complications and compliance issues. Emerging data indicates that it is a safe, effective and feasible alternative to systemic anticoagulation in patients with non-valvular AF. A number of devices have been developed for endocardial or epicardial based isolation of the left atrial appendage. Increasing experience has improved overall procedural safety and ease while simultaneously reducing device related complication rates. Furthermore, increasing recognition of the non-mechanical advantages of this procedure has led to further interest in its utility for further indications beyond the prevention of thromboembolic complications. In this review, we present a comprehensive overview of the evolution of left atrial appendage occlusion, commercially available devices and the role of this modality in the current management of AF. We also provide a brief outline of the landmark trials supporting this approach as well as the ongoing research and future prospects of left atrial appendage occlusion.

Pre- and Postprocedural CT of Transcatheter Left Atrial Appendage Closure Devices

Transcatheter left atrial appendage (LAA) closure is an alternative to long-term anticoagulation therapy in selected patients with nonvalvular atrial fibrillation who have an increased risk for stroke. LAA closure devices can be implanted by means of either an endocardial or a combined endocardial and epicardial approach. Preprocedural imaging is key to identifying contraindications, accurately sizing the device, and minimizing complications. Transesophageal echocardiography (TEE) has been the reference standard imaging modality to assess the anatomy for LAA closure and to provide intraprocedural guidance. However, CT has emerged as a less-invasive alternative to TEE for pre- and postprocedural imaging. CT is comparable to TEE for exclusion of thrombus but is superior to TEE for the delineation of complex LAA anatomy, measurement for device sizing, and evaluation of pulmonary venous and extracardiac structures. CT provides accurate measurements of the LAA ostial diameter, landing zone diameter, and LAA length, which are vital for accurate sizing of the device. CT allows evaluation of the relationship with the pulmonary veins and other adjacent structures that can be injured during the procedure. CT also simulates procedural fluoroscopic angles and provides evaluation of the interatrial septum, which is punctured during LAA closure. CT also provides a more convenient method for the evaluation of postprocedural complications such as incomplete closure, peridevice leaking, device-related thrombus, and device dislodgement. Online supplemental material is available for this article. ^©RSNA, 2021.

Safety and effects of volume loading during transesophageal echocardiography in the pre-procedural work-up for left atrial appendage closure

Background

In patients undergoing left atrial appendage (LAA) closure, an accurate sizing of the LAA is key to optimize device sizing, procedural success and reduce complications. Previous studies have shown that intraprocedural volume loading increases LAA dimensions and improves device sizing. However, the safety and effects on LAA and device sizing of administering a fluid bolus during pre-procedural transesophageal echocardiography (TEE) are unknown. The aim of this study was to determine the safety and impact on LAA dimensions and device sizing of an intravenous (IV) fluid bolus administered during TEE in the setting of the pre-procedural work-up for LAA closure.

Methods

The study included a total of 72 patients who underwent TEE to assess suitability for LAAC and received a 500 ml IV bolus of normal saline. The LAA landing zone (LZ) and depth were measured by TEE before and after volume loading, and these measurements were used to predict the device size implanted during a subsequent percutaneous LAAC procedure.

Results

There were no complications associated with volume loading. The baseline mean LZ was 19.6 ± 3.6 mm at 90^o, and 20.2 ± 4.1 mm at 135^o. Following fluid bolus, the maximum diameter increased 1.5 ± 1.0 mm at 90^o (p<0.001), and 1.3 ± 1.0 mm at 135^o (p<0.001). The baseline mean depth of the LAA was 26.5 ± 5.5 mm at 90^o, and 23.9 ± 5.8 mm at 135^o. After fluid bolus, the mean depth increased by 1.5 ± 1.8 mm (p<0.001) and 1.6 ± 2.0 (p<0.001), at 90^o and 135^o, respectively. Sizing based on post-bolus measurements of the LZ significantly improved the agreement with the final device size selection during the procedure in 71.0% of cases (vs. 42.0% with pre-bolus measurements).

Conclusions

Volume loading during ambulatory TEE as part of the pre-procedural work-up of LAAC is safe and significantly increases LAA dimensions. This strategy may become the new standard, particularly in centers performing LAAC with no TEE guidance, as it improves LAA sizing and more accurately predicts the final device size.

Risks and Benefits of Removal of the Left Atrial Appendage

PURPOSE OF REVIEW

In patients with atrial fibrillation who are unable to take novel oral anticoagulants for stroke prophylaxis due to bleeding risk or other contraindications, left atrial appendage (LAA) occlusion and exclusion devices have shown benefit. In this review, we highlight the risks and benefits associated with LAA removal.

RECENT FINDINGS

LAA, once considered a vestigial organ, has been shown to have physiological, anatomical, and arrhythmogenic properties. Device-related complications such as pericardial effusion, device embolization, device-related thrombus, while uncommon, are still present. With increased operator experience related to appendage occlusion, overall procedural complications have declined. Further refinements in device technology will help decrease complications. While benefits of appendage removal are plenty, procedural complications need to be weighed into the equation when making decisions regarding LAA occlusion.