Abstract

Introduction

Percutaneous left atrial appendage closure (LAAC) is an established stroke prevention strategy in patients with atrial fibrillation contraindicated for long-term anticoagulation.^1,2 However, peridevice leak (PDL) remains a significant limitation, occurring in 25.8% of patients at 45-day follow-up.³ Persistent PDL is associated with a 4.25-fold increased risk of transient ischemic attack, ischemic stroke, or systemic embolism (adjusted subdistribution hazard ratio, 4.25; 95% confidence interval (CI): 1.91-9.44; P < .001).⁴ Posterosuperior PDL locations present particular technical challenges for percutaneous closure. Mixed reality (MR) shows promise for preprocedural planning in complex structural interventions.⁵ The first application of MR-guided planning for PDL closure after LAAC is reported.

Case Report

A 69-year-old male with paroxysmal atrial fibrillation (CHA₂DS₂-VASc score 4), hypertension, insulin-dependent type 2 diabetes mellitus, dyslipidaemia, and hypothyroidism underwent LAAC. Anticoagulation was contraindicated due to spontaneous intracerebral haemorrhage in 2015.

In October 2023, a Watchman Flex 31 mm device (Boston Scientific, Marlborough, MA, USA) was implanted under general anesthesia with transoesophageal echocardiographic (TEE) guidance. Two redeployments were required due to initial shallow positioning. Dual antiplatelet therapy (aspirin 100 mg, clopidogrel 75 mg) was initiated following anticoagulation discontinuation at 6 weeks (patient timeline detailed in Supplementary Table 1).

Six-month TEE surveillance revealed a posterosuperior PDL (3 mm jet, 12 × 4 mm cavity) with color Doppler demonstrating bidirectional flow and systolic predominance, communicating with residual appendage tissue (Figure 1A and B). Cardiac computed tomography confirmed complex cavity morphology (12 × 6 × 9 mm) with asymmetric flow characteristics: wide communication between LAA and peridevice cavity (4.5-7.8 mm) (multimodality imaging analysis in Supplementary Table 2).

Preprocedural planning utilized the HJPHub MR (distinct from magnetic resonance imaging) system on Microsoft HoloLens 2 (Microsoft Corporation, Redmond, WA, USA)⁶ (specifications in Supplementary Table 3). Three-dimensional holographic visualization enabled detailed assessment of complex left atrial anatomy (Supplementary Video 1), identification of optimal posteroinferior transseptal puncture site, and predicted the need for telescoping catheter technique (Figure 2).

In October 2024, PDL closure was performed under general anesthesia with TEE guidance. Following transseptal puncture, an Agilis 8.5 F steerable sheath and Vista IMA 6 F guiding catheter enabled cannulation of the posterosuperior cavity. Wire access was achieved with a Sion Black guidewire through a Lantern 130 cm microcatheter. Closure was accomplished using 1 RUBY POD 12 coil (Penumbra, Alameda, CA, USA) deployed within the cavity, followed by a 15 cm Packing Coil at the neck, achieving complete occlusion confirmed by TEE and angiography (procedural details in Supplementary Table 4 and Supplementary Video 2).

Three-month follow-up imaging demonstrated complete resolution with no contrast penetration behind the occluder on cardiac computed tomography (Supplementary Video 3) and no residual leak on TEE (Figure 1C and D). Given an absolute oral anticoagulation contraindication, the patient continues on aspirin monotherapy with planned annual imaging surveillance, without adverse events.

Discussion

This case demonstrates several clinically important findings. First, a significant PDL with bidirectional flow was identified communicating with residual appendage tissue containing organized intracavitary thrombus, distinct from device-related thrombus on the occluder surface. The PDL constituted the primary indication for intervention, as persistent flow around the occluder represents ongoing stroke risk. This reinforces the importance of systematic PDL surveillance regardless of antithrombotic strategy, given the established association between PDL and thromboembolism (pooled odds ratio 2.04).⁷

Second, this represents the first application of mixed reality-guided planning for PDL closure. The HJPHub system enabled three-dimensional assessment of complex anatomy, facilitating optimal transseptal puncture site selection. Critically, despite real-time TEE navigation, the cavity entry could not be cannulated—even with live 3D TEE. Only by returning to MR planning during the intervention—to regain three-dimensional spatial orientation after TEE navigation had been exhausted—was successful navigation achieved; real-time catheter guidance was thereafter performed under fluoroscopy. The exceptional procedural complexity—fluoroscopy time 177.5 minutes (~11× published series), air kerma 4415.5 mGy (~10× typical LAAC values), and 6 catheter exchanges—underscores the technical challenge where TEE visualization may be suboptimal. Mixed reality planning proved indispensable, enabling success unattainable with conventional imaging alone. Notably, this indispensable contribution was qualitative in nature—three-dimensional spatial re-orientation rather than quantitative measurements or catheter simulation, neither of which is yet available in the current system; these capabilities represent clear directions for future development.

Third, coil embolization was selected for this irregular, non-circular cavity morphology. Detachable coils represent the most commonly utilized PDL closure device (42.3%) in multicenter registries, offering conformability advantages over plugs or occluders for complex geometries.^8,9 Residual leak represents a recognized complication across transcatheter structural interventions.¹⁰

Limitations include single-case observation, precluding generalizability, and the need for longer-term follow-up to assess durability. Randomized data evaluating MR-guided planning for structural interventions remain unavailable.

Conclusion

Peridevice leak closure procedures are inherently complex, requiring extensive operator expertise and specialized equipment. Mixed reality guidance using the validated HJPHub system facilitated successful coil embolization of a challenging posterosuperior PDL following LAAC.

Supplementary Materials

Footnotes

AI Disclosure: AI-assisted technologies were utilized for language refinement. All clinical data, scientific interpretation, and conclusions represent the independent work of the authors.

Informed Consent: Written informed consent was obtained from the patient.

Declaration of Interests: The authors have no conflicts of interest to declare.

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