3D printing for sizing left atrial appendage closure device: Head-to-head comparison with computed tomography and transesophageal echocardiography.

Aims: Device sizing for LAA closure using transoesophageal echocardiography (TEE) can be challenging due to complex LAA anatomy. We investigated whether the use of 3D-printed left atrial appendage (LAA) models based on preprocedural computed tomography (CT) permits accurate device sizing. Methods and results: Twenty-two (22) patients (73 +/- 8 years, 55% male) with atrial fibrillation requiring anticoagulation at high bleeding risk underwent LAA closure (WATCHMAN device). Preprocedurally, LAA was sized by TEE and third-generation dual-source CT. Based on CT, 3D printing models of LAA anatomy were created for simulation of device implantation. Device compression was assessed in a CT scan of the 3D model with the implanted device. Implantation was successful in all patients. Mean LAA ostium diameter based on TEE was 22 +/- 4 mm and based on CT 25 +/- 3 mm (p=0.014). Predicted device size based on simulated implantation in the 3D model was equal to the device finally implanted in 21/22 patients (95%). TEE would have undersized the device in 10/22 patients (45%). Device compression determined in the 3D-CT model corresponded closely with compression upon implantation (16 +/- 3% vs. 18 +/- 5%, r=0.622, p=0.003). Conclusions: Patient-specific CT-based 3D printing models may assist device selection and prediction of device compression in the context of interventional LAA closure.