Abstract 3819: Cardiac Computed Tomographic Angiography Pre-procedural Planning for Percutaneous Atrial Septal Defect Closure
Background: Secundum atrial septal defect (ASD) is a common congenital defect in adults. Percutaneous closure using implantable occluder devices is an image-guided procedure that can be performed by skilled operators in most adults with suitable anatomy.
Objective: To determine the feasibility and accuracy of using cardiac computed tomographic angiography (CTA) to visualize and characterize ASD 3-dimensional (3-D) anatomy prior to percutaneous closure and to determine if the plane of the inter-atrial septum is shifted in patients with ASDs.
Methods: 40-slice cardiac CTA was performed on 14 consecutive patients (11 female, 3 male, mean age 59±18 years old) who were referred for percutaneous ASD closure and 14 age and gender matched controls. The CTA reader was blinded to all clinical data. All defect patients had intra-cardiac and/or trans-esophageal echocardiographic (TEE) assessment of ASD size and location prior to or during percutaneous closure.
Results: CTA identification of ASD size, location and surrounding tissue rims was successful in all 14 patients with defects and not identified in all 14 control patients. 12 patients proceeded with percutaneous ASD closure. One patient had surgical repair due to identification of a sinus venous ASD not detected on TEE. One patient did not meet clinical criteria for closure with a small patent foramen ovale. CTA assessment of ASD size (range 1–24 mm) correlated well with ultrasound measurement (y=1.003x, R=0.996, p<0.0001). The inter-atrial septum plane orientation was variable and not statistically different between ASD and control groups (right anterior oblique (RAO) 13–43°, mean 29±11°, caudal 15–36°, mean 29±11°; RAO 16–47°, mean 32±10°, caudal 21–51°, mean 30±8°, respectively).
Conclusions: Cardiac CTA is an accurate and feasible non-invasive method to visualize and characterize ASDs. The intrinsic 3-D nature of CT provides better anatomic visualization than 2-dimensional ultrasound or fluoroscopic imaging techniques. Future applications of CTA assessment of ASDs includes pre-selection of properly sized devices, delivery catheters and best x-ray and ultrasound working views prior to percutaneous closure in order to improve procedural success and reduce invasive times and radiation exposure.