Page 13 - Journal of Structural Heart Disease Volume 3, Issue 1

Original Scienti c Article
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cluders such as the ADO is the “gold standard” [3]. De- spite the e ectiveness of currently available devices, procedural challenges remain, especially when small infants and/or large PDAs are involved. Moreover, in- creasing experience with transcatheter techniques has resulted in interventional cardiologists attempt- ing to more frequently treat patients who have PDAs with complex morphologies [6]. Therefore, there still is a demand for an ideal PDA closure device. Theoret- ically, such a device would have a design adaptable to any shape or size of PDA, regardless of patient age and weight, and achieve immediate closure in 100% of cases. The implantation technique would also be operator-friendly. In addition to addressing current shortcomings, such a device would reduce the need for catheterization laboratories to stock several types of products with di erent sizes. These remaining un- ful lled needs justify ongoing research and develop- ment of new device models.
The ODO Device
The ODO device was developed with the aim of ad- dressing some of the above-mentioned drawbacks. Even though our study was not comparative, the ODO device resembles the ADO I device with respect to design, intended use, and speci c application, which provides an “experimental-feeling” compari- son between the two devices. In fact, the ODO device material and delivery system and techniques are very similar to those of the ADO I. Notwithstanding these similarities, radical modi cations in the shape of the ODOwereintroduced.Thecoreofthedeviceiswider at the pulmonary end than at the aortic end, the distal clamp at the aortic end (in the ADO) is not present, and the screw attachment protrudes from the pulmonary end. This shape, which resembles a champagne cork, takes advantage of the bene ts of both the ADO I (i.e., in exible connection between the aortic disc and de- vice core) and the ADO II (i.e., aortic and pulmonary retention discs). In addition, retrieval of the device in case of accidental embolization is theoretically easier because the screw protrudes from the pulmonary end after release, making it more accessible for snaring.
Given that the ODO is available in larger sizes than the ADO devices, it allows closure of larger-sized PDAs. In fact, prior to the launch of the ODO, in some stud- ies, patients with large PDAs had to be excluded due
to non-availability of larger devices [7]. Another cru- cial di erence from the ADO I is that the ODO comes in two length options: standard and long shank. The long variant may be needed in some “slow tapering” type A or nonconical long and large PDAs. In one pa- tient in our series with a large (3 mm) and long (11 mm) type D PDA, the ODO 5-7 long device was clearly the most suitable (Figure 2). Before the introduction of the ODO, our best option would have been to de- ploy an ADO I, including its aortic retention disc, in the PDA body. This was in fact successfully performed in a similar case in a previous study [3].
Device Selection
In the rst few cases, the size of the aortic end of the occluder shank was chosen based on the narrow- est diameter of the PDA, extrapolating our experience with the ADO I. After facing occurrences of aortic disc bulging (Figure 3), probably due to excessive over- sizing, we concluded that the shank size should be calculated based on the part to be “squeezed” by the duct. It is worth mentioning that the choice of sizing should take into consideration the systolo-diastolic variations of the duct size, particularly in larger ducts (>3 mm) [8].
Safety and E cacy
Reported case series in the literature con rm the high occlusive properties of the ODO, even though larger ducts usually require more time to close [8, 9]. Our present results demonstrate a 100% success rate (shunt closure and successful implantation) with zero mortality and no serious morbidity. In fact, we noted a 90% closure rate at day 1, reaching 100% at 1-month follow-up. In our series as well as a recent- ly reported case series of PDA closure with the ODO device, no major adverse events (e.g., accidental de- vice embolization, signi cant aortic or pulmonary ob- struction, endocarditis, hemolysis or vascular injury) were encountered [10]. Considering the high degree of similarity between the Occlutech and Amplatzer devices and that most complications are seen during or shortly after implantation, it is reasonable to infer comparable safety of the two devices. Furthermore, reported late adverse events were very rare [11, 12], and therefore no further major adverse events are ex- pected from studies of the ODO device.
Journal of Structural Heart Disease, February 2017
Volume 3, Issue 1:1-7