Page 35 - Journal of Structural Heart Disease Volume 4, Issue 4

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Meeting Abstracts
Duct Occluder was deployed and released with a satisfac- tory echocardiographic and angiographic result. However, there was spontaneous embolization to the descending aorta after 2 hours, necessitating transcatheter retrieval of the device from the venous end with a Gooseneck snare, and PDA occlusion with a 6/8 Cera Duct Occluder.
The 2nd case was 6-month, 5.5 kg, with a Krichenko Type E PDA with a tubular PA end. The Lifetech Cera 4/6 mm Duct Occluder chosen initially embolized to the descending aorta soon after release, requiring transcatheter retrieval from the arterial side and PDA occlusion with a 6/6 mm ADO2 device.
The lower pro le and softer design of the ceramic coated devices generally allows a smaller delivery sheath size and easy deployment, which is advantageous in small children. Our standard sizing dictum for the ADO and similar devices has been 2 mm above the narrowest PA end. However, in slightly tubular PDAs as ours, there may be no protrusion of the PA end of the device from the PDA, with no con- sequent distal splay of the PA end, and a possible recoil during release. Also, as the softer ceramic devices would exert less perpendicular stenting forces on the ductal wall, the only stabilizing segment is the retention skirt. Hence, downward descending aortic systolic forces on the reten- tion skirt could potentially dislodge the device.
We conclude that perhaps the softer ceramic coated devices need to be oversized by one size to form a tighter waist, or Nitinol ADO type devices or even ADO2 or vas- cular plugs may be preferable devices for slightly tubular ducts.
46. ESTIMATING RADIATION EXPOSURE DURING PEDIATRIC CARDIAC CATHETERIZATION; A POTENTIAL FOR RADIATION REDUCTION WITH AIR GAP TECHNIQUE
Reid Chamberlain, Alexis Shindhelm, Gregory Fleming, Kevin Hill
Duke University, Durham, USA
Background: Patients with congenital heart disease fre- quently undergo cardiac catheterization exposing them to harmful ionizing radiation. The air gap technique (AGT) is a novel approach to radiation dose optimization during cardiac catheterization where an “air gap” is used in place of an anti-scatter grid to reduce dosing. This technique remains largely untested in children and may confer a bene cial reduction in radiation exposure. We hypothe- size the AGT has di erential e ects on absorbed radiation
dose depending on patient size with most bene t in larger patients and with lateral imaging where scatter irradiation is greatest.
Methods: Fluoroscopy and cineangiography were per- formed using a Phillips Allura Fluoroscope on tissue simu- lation anthropomorphic phantoms (CIRS, Norfolk, VA) ages 0, 5 and 15 years. Testing was rst performed using a stan- dard imaging approach (anti-scatter grid removed in the neonate and 5 year; kept in place for the teenager). Images were then repeated using the air gap technique, con- structed so as to appear identical to the baseline images. Air Kerma per 1000 frames was measured and input to Monte Carlo simulation software (PCXMC, Amsterdam, Netherlands) to estimate e ective dose in millisieverts. Objective image assessments performed using image quality phantom (CIRS, Norfolk, VA).
Results: E ective radiation doses for the neonate and 5 year phantom were similar or increased when using the AGT compared to standard imaging for both PA and lateral imaging when using recommended imaging guidelines. When the anti-scatter grid is placed for the 5 year phan- tom, the e ective radiation dose increases an average 53% for uoroscopy and 55% for cineangiography, thus exceed- ing AGT e ective radiation doses by 46% and 53%, respec- tively. In the teenage phantom the AGT reduced e ective doses by 21% for uoroscopy and 28% for cineangiogra- phy. The AGT increased geometric magni cation but the di erence in image blur and contrast was not signi cant for any of the phantom imaging.
Conclusions: The air gap approach is an e ective tech- nique for dose reduction in larger patients where scatter irradiation is signi cantly increased, particularly when higher magni cation is needed.
47. THE INCIDENCE OF RECURRENT LARYNGEAL NERVE INJURY RESULTING IN VOCAL CORD PARALYSIS FOLLOWING INTERVENTIONAL PEDIATRIC CATHETERIZATION PROCEDURES: AN INFREQUENT AND UNRECOGNIZED ENTITY. Howard Weber1, Athar Qureshi2, Rajiv Devanagondi3, Sara Trucco4, Agustin Rubio5, Jaana Pihkala6, Mark Law7, John Bass8, Lourdes Prieto9, Daniel Levi10, Daniel Turner11
1Penn State Hershey Childrens Hospital, Hershey, USA. 2Texas childrens Hospital, Houston, USA. 3University of Rochester Medical Center, Rochester, USA. 4Pittsburgh Childrens Hospital, Pittsburgh, USA. 5Seattle Childrens Hospital, Seattle, USA. 6Helsinki University Childrens Hospital, Helsinki, Finland. 7University of Alabama at Birmingham, Birmingham, USA. 8University of Minnesota, Minneapolis, USA. 9Nicklaus Childrens
Hijazi, Z
21st Annual PICS/AICS Meeting