Page 50 - Journal of Structural Heart Disease Volume 5, Issue 4

Meeting Abstracts
112
Jeng-Sheng Chang1,2, Yun-Ching Fu1,2, Yi-Chin Peng1, Ping- Yun Chiou1
1Children's Hospital, China Medical University, Taichung, Taiwan. 2College of Medicine, China Medical University, Taichung, Taiwan
A 13-year-old boy of d-TGA had arterial switch opera- tion with Lecompt maneuver soon after birth. Follow up echocardiographic studies revealed a supravalvar PS of 50 mmHg gradient. Balloon angioplasty one year ago did not resolve the gradient. The narrowest segment, ‘waist’, was 9.0mm in diameter, while the sinus valsalva portion of the MPA was 17.7mm in diameter. The distance between the tips of pulmonary valve (PV) at opening and the roof of the MPA was 31.1mm. The waist was closer to the PV tips than to the PA roof. We chose to use a Cheatham Platinum (CP) bare stent of 34 mm long (CP8Z34). At first, we use aortic root angiogram to confirm that the coronary arteries were not compressed by a fully inflated 18mm x 4cm XXL balloon catheter in the RV outflow tract. With a stiff wire remained in the LPA, we then advanced the 16mm-4cm balloon-in-balloon catheter-mounted stent combination set to the ‘waist’. The inner balloon dilation began to open the stent to 8 mm in diameter. Assisted with bouts of con- trast injection from the long sheath, we made fine adjust- ment on the stent location to make sure it had neither interfered to the movements of PV, nor to leave a too short proximal portion of stent to anchor stably on the waist. Finally, the outer balloon-and-stent was slowly and fully inflated up to 5 atm pressure. To make the stent an ampulla shape, we re-dilated its proximal end with the same bal- loon catheter. The full stent length was shortened from 34 mm to 28.4mm. The waist and the proximal end were 14.3 and 16.6 mm in diameter, respectively. The stent appeared stable on the waist, though shorter in its proximal side than that of the distal side. The pressure gradient dropped to 20mmHg. The systolic pressure gradient ratio between RV and AO dropped from 61/97(0.63) to 54/141(0.38) mmHg. Contrast media flew to bilateral PA smoothly.
65. BENCH TESTING OF MECHANICAL PROPERTIES OF LOW-DIAMETER BALLOON EXPANDABLE COVERED STENTS CURRENTLY AVAILABLE FOR USE IN PEDIATRIC PATIENTS.
Benjamin Blais1, Karen Carr1, Sanjay Sinha1,2, Daniel Levi1
1UCLA Mattel Children's Hospital, Los Angeles, USA. 2CHOC Children's Hospital, Orange, USA
Objective: To determine post dilation potential and cover integrity of 5-12mm Atrium, VBX, and Lifestream balloon expandable covered stents.
Background: Covered stents can treat ruptures and aneu- rysms in patients with congenital heart disease and are often dilated well beyond their implant diameters. The foreshortening, recoil, and covering/stent integrity with serial dilations is clinically important information for interventionalists.
Methods: Serial dilations of the 5-10mm Atrium, VBX, and Lifestream covered stents were performed in 1-2 mm increments from 5mm to 20mm with measurements of foreshortening, recoil and stent/cover integrity, both with nominal balloon expansion and post-dilation. Additional data characterizing fabric coating tears, strut narrowing, and stent fracture were collected for all three types of stents.
Results: All stents met expected labeled performance for their intended delivery balloon. Average foreshorten- ing was most significant with VBX stents at 40-50% when dilated with balloons 4-5mm above crimped labeled diam- eter (CLD). Lifestream stents did not reach 40-50% fore- shortening until dilated with balloons 10-11mm above the CLD, followed by Atrium stents which reached max- imum foreshortening of 20-30% when over-dilated by 10-11mm. The VBX stents tended to foreshorten from the outside inward, eventually forming a short ring. Average recoil was most notable for Lifestream stents at 8-10% on dilation with the nominal delivery balloon, and similarly on over-dilation with balloons 1-4mm above (compared with average recoil of 3-6% for Atrium stents and 1-2% for VBX stents under the same circumstances). After 5-7mm of over-dilation from nominal the recoil was roughly the same at <3% for all stent types. Excluding an outlier (the 5mm Atrium collapsed into a tight ring), fabric covering tore earliest with the Atrium stents, reaching an aver- age of 5mm above nominal before tearing. The VBX and LIfestream stents maintained cover integrity until dilations greater than 8-9mm above nominal. The Lifestream stents tended to fracture at an average of 10-11mm greater than nominal, whereas the VBX and Atrium stents fractured at 8-9mm and 6-7mm above nominal respectively.
Conclusions: Both the VBX and Lifestream stents main- tained cover integrity until dilations greater than 8-9mm above nominal. The Atrium stent lost fabric integrity at the lowest and the VBX stent had the greatest foreshorten- ing diameters. The Lifestream stents had the greatest post dilation potential and were able to be fractured at >10 mm above nominal.
Journal of Structural Heart Disease, August 2019
Volume 5, Issue 4:75-205