Page 108 - Journal of Structural Heart Disease Volume 5, Issue 4

Meeting Abstracts
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underwent DH BRS stent implantation in the descending aorta (DAO) and iliac arteries. Premounted metal stents were placed in contralateral iliac arteries for comparison. Stents were sized and expanded to 110% of native ves- sel size. The BRS were examined for stent patency, vessel inflammation, stent degradation and late lumen loss at 2years, 2.5years, 3years, 3.5years and 5years following stent implantation. Imaging consisted of angiography and intravascular ultrasound (IVUS) prior to stenting (baseline), immediately post stenting and at subsequent follow up intervals. Long term histological evaluation through differ- ent phases of degradation from revascularization, resorp- tion and restoration was examined.
Results: Nine of 12 rabbits (3.6-4.4 kgs) underwent suc- cessful stent implantation in the DAO and iliac arteries. 3 animals died during initial stent implantation procedure. All 9 animals following successful stent/s implantation survived to predetermined time points with no evidence of limb ischemia. Angiography and IVUS showed stent/ vessel patency, trivial in stent restenosis and no evidence of thrombus. Late lumen loss analysis showed that there is vessel growth in arteries with BRS implantation (Table 1). There was no vessel growth in iliac arteries with metal stents (Table 2). Immunohistological stains, SMC-α, showed integration of smooth muscle cells from 1-5 years of implantation in BRS. Ki-67 staining of the BRS showed the smooth muscle cells being active with proliferation at years 1-2 during the resorption phase but not years 3-5 in the aorta and not after 2.5 years in the iliac vessel during the artery restoration phase. At 2.5 years the BRS was not visible in the aorta shown by surface examination using scanning electron microscopy. At years 3-5(restoration phase) the BRS disappears showing some granuloma of the arterial vessel with no in-stent restenosis, no thrombus.
Conclusion: Long term results of the novel DH BRS spe- cifically designed for CHD are promising. Overall this BRS has shown on angiograms and IVUS no thrombus forma- tion, no stent migration, no significant in stent stenosis, no dissection, no aneurysm and no clinical events or deaths following successful stent placement. The BRS design demonstrated distinct slow resorption profiles in compar- ison to other degradable stents. These results indicate the importance of the resorption properties of the device on its vascular compatibility. In this study, this BDS has shown equivalence to metal stent in radial strength and low inflammation throughout the degradation process and ultimately leaving behind a native vessel. These results are consistent with others who have demonstrated the impor- tance of controlling the rate of implant resorption within the initial critical vessel healing period.
139. CUTTING BALLOON ANGIOPLASTY ON BRANCH PULMONARY ARTERY STENOSIS IN CONGENITAL HEART DISEASE
Harrison Cobb1,2, Joshua Daily1,2, Amy Dossey1,2, Michael Angtuaco1,2
1University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. 2Arkansas Children's Hospital, Little Rock, Arkansas, USA
Background: Cutting balloon angioplasty has emerged as an alternative therapy for pulmonary artery stenosis resis- tant to conventional balloon techniques with good short term results, but sparse data on long-term outcomes. We sought to determine if the initial increases in pulmonary arterial diameter following cutting balloon angioplasty are maintained in long-term follow-up.
Methods: This study is a descriptive, retrospective chart review of patients with congenital heart disease who underwent cutting balloon angioplasty for pulmonary artery stenosis at Arkansas Children’s Hospital between January 2008 and February 2019. We reviewed patient demographics, cardiac and genetic diagnoses, anthro- pometrics, details of each catheter-based interventions, as well as 30 day complications. Each pulmonary artery segment which underwent cutting balloon angioplasty was treated individually. Follow-up was ended if the spe- cific segment became atretic, or if the segment under- went an additional intervention surgical or catheter based intervention. Clinical records were reviewed to determine 30-day complications.
Results: Over the period of study, 47 patients underwent pulmonary artery cutting balloon angioplasty and were followed through 133 catheterization cases. Of the 47 patients, 40 underwent repeat catheterization. In total, 150 discrete cutting balloon events were performed on 112 pulmonary artery segments. The average age at ini- tial intervention was 36 months. Average time to end of follow-up was 34 months with a range from zero to 142 months. At the time of initial cutting balloon angioplasty, there was an average immediate increase in minimal ves- sel diameter of 59%. At the end of follow-up, the average increase in minimal arterial diameter maintained from pre-cutting balloon was 79%. Seventy eight pulmonary artery segments underwent repeat intervention. Seven patients had 30-day complications including 1 death.
Conclusions: In this study reporting the longest follow-up to date of children and adolescents who underwent cut- ting balloon angioplasty for branch pulmonary artery stenosis, we found that cutting balloon angioplasty was
Journal of Structural Heart Disease, August 2019
Volume 5, Issue 4:75-205