3D Printing Technology For Planning Left Atrial Appendage Occlusion

3D Printing Technology For Planning Left Atrial Appendage Occlusion: A Randomised Trial

Atrial fibrillation is the most common cardiac arrhythmia, affecting 8.5% of the general population in Hong Kong. Systemic embolization, and particularly stroke, is the most frequent major complication of atrial fibrillation. Long-term oral anticoagulation is recommended for most atrial fibrillation patients for prevention of embolism. However, such therapy is associated with an increased risk of bleeding and not all individuals are candidates for this therapy.

The left atrial appendage (LAA) is the usual source for clot that embolizes. Occlusion of the LAA ostium (LAAO) with percutaneous device in patients with nonvalvular atrial fibrillation has emerged as an alternative to anticoagulation for prevention of embolism.

Procedural success requires careful planning and understanding of the anatomy of LAA, as well as the interaction between the appendage and the occlusion device. However, complexity and variability of LAA anatomy exists and these anatomical variations among individuals poses challenges to accurately sizing and positioning the device. Certain anatomic variations of the appendage, for instance the presence of a sharp bend in the proximal or middle portion of the dominant lobe, or prominent pectinate muscles, pose particular challenge to device implantation and demands pre-specified implantation technique. Assessment of LAA anatomy relies on imaging, usually combining peri-interventional 2D transesophageal echocardiography (TEE) with fluoroscopy guidance and, less frequently, with pre-interventional computed tomography (CT). Because lobes of the LAA exist in different planes, imaging must be done in multiple planes to visualize the entire LAA. Even with advanced imaging, complete understanding the 3D geometry of the appendage is challenging, and the mechanical interaction between the device and the anatomy is difficult to predict or quantify.

The limitation of imaging in the assessment of LAA anatomy may lead to inaccurate device sizing. Over- or under-sizing increase the chance of pericardial effusion, incomplete occlusion, and device embolization. Incomplete occlusion of the LAA ostium is common and may jeopardise the procedural efficacy in embolism prevention. Device re-sizing during procedure prolongs procedural time as well as radiation exposure; moreover, device re-positioning within the appendage may cause inadvertent tissue injury and increase the risk of cardiac perforation. Indeed, procedural complication rate of LAAO remains fairly high in real-world practice.

3D printing (3DP) is a novel technology able to create a patient-specific model of any given anatomical portion of the heart for preoperative device testing and procedural simulation. The simulation "rehearsal" experience can enhance the operator's confidence, allowing the operator to anticipate difficulties before the actual intervention; this potentially reduces the procedural time (hence cost and radiation hazard), device re-sizing, the number of deployment attempts, and promotes procedural success.

The aim of this project is to evaluate the effect of 3D-printed patient-specific LAA model compared with standard imaging planning on procedural efficacy and safety of LAAO.

The project will be divided into two parts:

Part I Technical validation of 3D-printed LAA models Validation of anatomical accuracy and material properties of the 3D-printed LAA model will be conducted in 30 patients referred for clinically indicated surgical excision of the LAA.

Part II Randomised clinical trial on additive benefit of 3D printing for LAAO. The investigators will conduct a randomized, controlled, open-label, trial in 200 patients undergoing LAAO for stroke prevention in our hospital.

Eligible subjects will be randomly assigned by a computer program in a 1:1 ratio to either preoperative planning using 3D-printed LAA model (3D printing arm) or standard imaging planning alone (no-3D printing arm).

The investigators hypothesize that preoperative 3DP planning could help in finding the correct position within LAA, sizing the device and guiding the choice of the closure device despite the measurements provided by imaging alone.

Study Overview

• Status: Completed
• Conditions: Atrial Fibrillation (AF); Cost Benefit Analysis; 3D Printing
• Intervention / Treatment: Device: 3D-printed models of the left atrial appendage; Other: Standard preoperative planning

• Study Type: Interventional
• Enrollment (Actual): 184
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • New Territories
    • Hong Kong, New Territories, Hong Kong, Sha Tin
      • Division of Cardiology, Department of Medicine and Therapeutics Faculty of Medicine, The Chinese University of Hong Kong

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥18 years
• Non-valvular atrial fibrillation
• CHA2DS2-VASc ≥2
• Absolute or relative contraindications to long-term oral anticoagulation (e.g. history of intracranial or life-threatening bleeding, HAS-BLED ≥3, triple anticoagulant therapy)
• Planned for LAAO procedure

Exclusion Criteria:

• Intracardiac thrombus is visualized by echocardiographic imaging
• An atrial septal defect repair or closure device or a patent foramen ovale repair or closure device is present
• The LAA anatomy will not accommodate a device
• Any of the customary contraindications for other percutaneous catheterization procedures (e.g., patient size too small to accommodate TEE probe or required catheters) or conditions (e.g., active infection, bleeding disorder) are present.
• Known hypersensitivity to any portion of the device material or the individual components
• Comorbidities other than atrial fibrillation that required oral anticoagulation
• Suboptimal LAA image on TEE or CT that is inadequate for 3D modelling and printing
• Refusal to participate the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 3D printing arm; In the 3D printing arm, pliable 3D-printed LAA models will be created 1 week before the planned LAAO procedure using methodology described above. Preoperative procedural simulation will be conducted by testing different types (Watchman [Boston Scientific Inc.] and Amplatzer Amulet [St Jude Inc.]) and sizes (21-33mm for Watchman, 16-34mm for Amulet) of locally available LAAO devices on the 3D-printed pliable appendage model to determine the optimal device type and size that achieve proper positioning, stability, and complete occlusion of the ostium.	Device: 3D-printed models of the left atrial appendage; Participants receive preoperative planning using patient-specific 3D-printed models of the left atrial appendage. This arm includes procedural simulation with different occlusion devices and sizes to optimize the intervention.
Other: Non 3D printing arm; In the no-3D printing arm, standard preoperative planning based on preoperative imaging, namely, multi-planar 2D/3D TEE and, in selected cases at the physician's discretion, pre-interventional CT.	Other: Standard preoperative planning; Participants undergo standard preoperative planning based solely on traditional imaging techniques, such as 2D/3D transesophageal echocardiography (TEE) and optionally computed tomography (CT).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess the rate of complete occlusion of the ostium	This will be determined by the absence of peri-device flow on color Doppler imaging or if the jet width is less than 1 mm.	The occlusion rate will be assessed during the procedure and at the 45-day TEE follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Procedural complications	Pericardial effusion, cardiac perforation, device embolization, procedure-related stroke, bleeding.	During the procedure

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Procedural time	Measure the time taken for the LAAO procedure.	During the procedure
Fluoroscopic time	Assess the duration of fluoroscopy used during the procedure.	During the procedure
Radiation Exposure	Evaluate the amount of radiation exposure to patients.	During the procedure
Iodinated contrast usage	Track the amount of contrast agent used during imaging.	During the procedure
Cost-Effectiveness of the 3D printing technology	A cost-effectiveness analysis will be performed using the cost of 3D printing per procedure over the number of device re-sizing, procedural complications, and their management (e.g. surgical drainage of pericardial effusion) avoided as well as procedural time shortened.	45 months
Device sizing accuracy	Compare the accuracy of the device sizing achieved with 3D printing versus standard methods.	Periprocedural
Device re-positioning	Count the occurrences of device adjustments needed during the procedure.	During the procedure and at 45-day TEE
Assessing the patient satisfaction with communication and understanding regarding the LAAO procedure	The day before intervention, each patient will be seen by the cardiologists for education on atrial fibrillation, the LAA and the interventional procedure. A questionnaire will be created to prospectively evaluate the level of patient's preoperative knowledge and understanding. This will at first be evaluated based on the TEE images of the LAA and secondly using the 3D-printed model in order to assess the improvement following the model presentation. The questionnaire will consist of questions to evaluate 3 components of patient knowledge: (a) basic LAA anatomy; (b) role of LAA in causing stroke in atrial fibrillation and rationale of LAAO, and (c) planned interventional procedure and its complication. Patient satisfaction and perception of the effectiveness of the patient-physician communication will also be assessed using a 10-point Likert-type scale.	The day before the procedure
Ischemic stroke	Monitor and document any occurrence of ischemic stroke.	During the procedure and at day 45 follow-up
Hemorrhagic stroke	Monitor and document any occurrence of hemorrhagic stroke.	During the procedure and at day 45 follow-up
Mortality	All mortality data will be systematically recorded and analysed as part of the study outcomes.	Monitored continuously throughout the study period (45 months) with evaluations at key follow-up points such as day 45 follow-up

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong
• Collaborators: The University of Hong Kong
• Investigators: Principal Investigator: Alex PW Lee, Professor, Chinese University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2017
• Primary Completion (Actual): January 31, 2022
• Study Completion (Actual): January 31, 2022

Study Registration Dates

• First Submitted: March 6, 2026
• First Submitted That Met QC Criteria: March 16, 2026
• First Posted (Actual): March 19, 2026

Study Record Updates

• Last Update Posted (Actual): March 19, 2026
• Last Update Submitted That Met QC Criteria: March 16, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Atrial Fibrillation; 3D printing; Left Atrial Appendage Occlusion
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Atrial Fibrillation
• Other Study ID Numbers: 2017.397-T

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No