The intracardiac echocardiography (ICE) technology uses a catheter-based steerable ultrasound probe passed into the vessels to image intracardiac structures and blood flow from inside the cardiovascular system, with a similar to superior image resolution as compared to transesophageal echocardiography (TEE). Its clinical applications in human cardiology are growing, particularly for interventional procedures. The aim of this pilot study was thus to assess the feasibility of ICE in the dog during interventional procedures, i.e., transcatheter PDA closures using Amplatz© Canine Ductal Occluder (ACDO).

Material and Methods

The study population consisted of 4 dogs (median age: 0,75 year [0,3–2,1]; body weight: 15,1 kg [9.2–20.8]). A type II morphology PDA with left-to-right shunting was visualized in all cases based on transthoracic echocardiography (TTE) using two-dimensional (2D) and three-dimensional modes, as well as color-flow Doppler recordings. In 2 dogs, previous unsuccessful surgical closure of a PDA by thoracotomy was reported by the referent veterinarians, with placement of several hemostatic clips (Case #1) and mild hemorrhage of the PDA corrected with resorbable hemostatic compresses (Case #2). The ICE ultrasound system ViewMate Z© and the ViewFlex Plus catheter© (St Jude Medical, 4.5–8.5 MHz) were manipulated in all cases by a trained highly experienced observer in ICE imaging modality and a second observer for imaging settings if needed.

Results

The ViewFlex Plus catheter was introduced by the left or the right femoral artery using a 9 to 10 French introducer (depending on dog's size) in all cases except for the smallest dog (9.2 kg), and was placed in the descending aorta dorsally to the ductus. In the two dogs that underwent a previous unsuccessful surgical closure of a PDA by thoracotomy, ICE provided a better evaluation of the PDA morphology (Case #1) and associated lesions (Case #2) than TEE. For Case #1, unlike ICE, TEE did not allow an optimal acoustic window to accurately visualize the PDA area because of the hemostatic clips. In all cases, ICE allowed confirmation of complete PDA occlusion using combined 2D and color-flow Doppler modes. Furthermore, in two dogs, ICE was used as the sole guidance for deployment of the ACDO device.

In conclusion, this report illustrates the safe and effective use of ICE in dogs during transcatheter procedures.

Disclosures

No disclosures to report.