Page 20 - Journal of Structural Heart Disease Volume 2, Issue 5

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Original Research Article
Figure 1. Percent of patients in study receiving each device size and their sizing score.The score includes 1 point for male sex, 1 point for an atrial septal aneurysm (septal excursion >15 mm on echocardiography), and 1 point for a patent foramen ovale tunnel >10 mm in length.
Figure 2. Receiver operating characteristic curve of the sizing score for association with implantation of an Amplatzer Septal Occluder “Cribriform” device ≥30 mm diameter. The score in- cludes 1 point for male sex, 1 point for an atrial septal aneurysm (septal excursion >15 mm on echocardiography), and 1 point for a patent foramen ovale tunnel >10 mm in length.
ing the shortest distance from the PFO to the aortic root and SVC. The recommendations call for implanta- tion of the 35 mm device if this distance is >17.5 mm, the 25 mm device if the distance is 12.5–17.4 mm, and a 1–8 mm device if the distance is 9–12.4 mm. If the shortest distance from the PFO to the aortic root or
SVC is <9 mm, the instructions prohibit implanting the Amplatzer PFO Occluder device. The instructions do allow for the use of a larger device in the setting of ASA, but there are not speci c recommendations for device size selection when ASA is present. These rec- ommendations rely on obtaining echocardiographic measurements from the PFO to both the aortic root and SVC. These measurements may be di cult to re- produce, especially in mobile, aneurysmal atrial septa. In addition, the instructions do not account for BMI or tunnel length, which could contribute to device slid- ing if smaller devices are chosen. It should be noted that the Amplatzer PFO Occluder has a larger RA disc than LA disc, for example, the 35 mm device has a 25 mm left atrial disc. The di erence in disc size may also contribute to device sizing, especially compared to the ASOC device that has discs of equal sizes. The CLO- SURE 1 trial protocol called for sizing balloon estima- tion of PFO size prior to closure but did not delineate how this would inform device size selection [24]. Bal- loon-sizing was optional in the PC trial, and device size selection was at the discretion of the treating physi- cian [23].
This study identi ed two echocardiographic nd- ings that were independently associated with larger device requirements for PFO closure: the presence of ASA and a long PFO tunnel. Aneurysm of the interatri- al septum is characterized by mobile atrial tissue that has a large distance of excursion during the cardiac cycle. This oppy tissue provides very little support for a closure device deployed across a PFO. There- fore, a larger device may be bene cial in such cases to provide additional support of septal architecture and continuously occlude the PFO. Long-tunnel PFO tracts are challenging for device closure because they require devices with either variable waist-length or large, strong discs to e ectively shorten the tunnel length. All of the closures completed in our study were performed with the ASOC device, which is a strong double-disc device. Larger disc diameters of the ASOC device could provide additional strength to e ectively shorten the long PFO tunnel length, which may explain why larger disc devices were used in the patients with longer tunnels. Interestingly, both ASA and long-tunnel length have been associated with risk for embolization, which may indicate that pa- tients with these ndings would bene t from larger
Venturini, J.M. et al.
Device Sizing for Percutaneous PFO Closure