Page 33 - Journal of Structural Heart Disease - Volume 1 Issue 2

Meeting Abstracts
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sion in the contralateral lung. Centers that participated included Tex- as Children’s Hospital, St Justine Hospital, and Rush University Med- ical Center.
Results: Three infants with right-sided DOPA who underwent un- complicated palliative ductal stenting were noted to develop severe pulmonary hypertension in the contralateral lung. None of these pa- tients had aortopulmonary collaterals. Case A received two 3x12mm Integrity stents (Medtronic, Minneapolis, MN) at birth; Case B received two 3.5x13mm Zeta coronary stent (Abbott Vascular, Santa Clara, CA) at 10 days and Case C received a 4x19mm Jostent covered coronary stent (Abott Vascular, Abbott Park, IL) at 6 months.
After developing severe pulmonary hypertension in the left lung, case A demonstrated clinical improvement only after prostaglandin infusion to open up the left ductus. This was subsequently stented with a 3x12mm Integrity stent and eventually the infant underwent surgical anastomosis of right pulmonary artery to the main pulmo- nary artery at 4 months. Case B underwent repeat catheterization demonstrating normal pressures in the RPA and LA, and was man- aged with pulmonary vasodilators for 1.5 months prior to surgical re-anastomosis. Case C required surgical banding of the ductal stent that lasted for a year before undergoing surgical re-anastomosis. Pul- monary artery pressures returned to normal in all patients following surgical re-anastomosis.
Conclusions: In these three cases we demonstrate the development of severe contralateral pulmonary hypertension following ductal stenting of a right sided isolated DOPA. Normalization of pulmonary artery pressures resolved in all cases following surgical re-anasto- mosis. With initial ductal stenting, the normally connected lung con- tinues to receive the entirety of systemic cardiac output, and thus is unlikely to have developed pulmonary hypertension due to excess pulmonary blood flow. The cause of pulmonary hypertension in the normally connected lung in these cases is unclear but we surmise the presence of a neuro-endocrine response to abrupt increase in flow to the lung with DOPA as a possible mechanism.
and to complete active resorption by 12 months. Bench evaluations of scaffold radial resistive force (RRF) and chronic outward force (COF) were conducted after simulated use in physiological conditions. In vivo scaffold tests were conducted in pulmonary arteries of rapid growing Micro Yucatan swine [median 8.5 (4.0-13.6) kg].
Results: The self-expanding scaffold is a composite of braided, biore- sorbable poly (L-lactide-co-glycolide) monofilaments coated with a cross-linked poly (lactide-co-caprolactone) elastomer. Radiopaque edge markers are incorporated into the device for fluoroscopic visu- alization. Radial resistive force is greater than a Genesis stent compar- ator (984 ± 39 mmHg vs 830 mmHg). The chronic outward force is 293 ± 13 mmHg, whereas conventional balloon-expandable stents have no outward force and therefore no ability to self-expand with ves- sel growth. In simulated 6 month in vitro testing, radial resistive and chronic outward forces declined 10-20% per month. Scaffolds were tested in vivo up to one year in rapid growing micro Yucatan swine. There was no acute or follow-up (3, 6, and 12 months) thrombosis, constrictive remodeling, or branch-loss and minimal neointimal pro- liferation. Scanning electron microscopy showed endothelialization at 1 month. Angiography confirmed 13 – 39% vessel diameter growth over the 12-month in-life duration. Micro CT and histology show suffi- cient resorption at one year.
Conclusions: Demonstrated performance features of this pediat- ric-specific bioresorbable scaffold include self-expansion, elasto- mer-strengthening, 6F-profile, and programmed degradation with- out need for drug elution. First-in-man clinical testing is planned for 2016.
#0074
COARCTATION OF THE AORTA: FUTURE RISK DESPITE ADEQUATE REPAIR
Melinda Cory, Thomas Zellers, William Scott, Claudio Ramaciotti1, Vivian Dimas
University of Texas Southwestern Medical Center, Dallas, TX, USA
Purpose: Patients (pts) with repaired coarctation of the aorta (CoA) have a shorter life expectancy than their peers. Coronary artery dis- ease/myocardial infarction is the most common cause of late death, likely due to abnormalities of the arterial endothelium. There is lim- ited long-term data for pediatric pts. We hypothesized that pts with CoA would show arterial endothelial dysfunction despite successful repair.
Methods: Pts >5 years of age with successful repair of CoA (defined as residual gradient <20 mmHg by echo or upper/lower extremity BP) without associated significant congenital heart disease (CHD) were included. Twenty-five pts were identified from August 1, 2011 until April 28, 2014, with successful enrolment of 11 pts. One pt was later excluded due to previously unidentified associated CHD. The average (avg) age was 15.3 ± 3.6 yrs. The avg corrected echo gradient post-re- pair was 11.3 mmHg ± 8.5. Evaluation included carotid intima media thickness (cIMT) measurement, flow mediated vasodilation (FMV) testing, exercise stress testing (EST), and 24 hour ambulatory blood pressure monitoring (ABPM).
Results: Not all pts enrolled were able to complete all components of the evaluation; some had unsatisfactory data for interpretation. Nine pts underwent EST, of which 3 (33%) met criteria for exercise-induced hypertension. One pt had SBP in the 90-95th percentile. Seven pts un-
#0073
FIRST-IN-MAN 2016:
ELASTOMERIC BIORESORBABLE SCAFFOLD TO TREAT PEDIATRIC PULMONARY ARTERY STENOSIS
Kanishka Ratnayaka1, Yina Kuang2, Danny Concagh2, Lisa Bergersen3, Maria Palasis3, Robert Lederman4, Lee Core2 1Children’s National Medical Center, Washington DC, USA
2480 Biomedical, Watertown, MA, USA
3Boston Children’s Hospital, Boston, MA, USA
4Division of Intramural Research, National Heart Lung & Blood Institute, National Institutes of Health, Bethesda, MD, USA
Background: No commercially available stents exist to treat small children without limiting vessel growth and requiring future surgical removal. Bioresorbable stents would revolutionize congenital heart disease by providing neonates and infants the therapeutic option of stent angioplasty.
Methods: A novel self-expanding bioresorbable scaffold (480 Biomed- ical, Inc) was designed to provide acute radial strength comparable to balloon-expandable metal stents commonly used in larger children (Palmaz Genesis, Cordis), to sustain radial strength up to 6 months,
NOVEL SELF-EXPANDING
Journal of Structural Heart Disease, August 2015
Volume 1, Issue 2: 36-111