Page 42 - Journal of Structural Heart Disease Volume 5, Issue 6

Case Report
266
Video 1. Shows the mobile thrombus on the occluder’s left atri- al disk. View supplemental video at https://doi.org/10.12945/j. jshd.2019.005.19.vid.01.
Discussion
Krumsdorf et al. [15] have investigated the inci- dence and clinical course of thrombus formation on atrial septal defect (n=407) and patent foramen ovale (n=593) closure devices in 1,000 consecutive patients, between august 1992 and January 2003. The mean age was 48 ± 15 years and nine different devices were used, Amplatzer (ASD and PFO devices) being the most used in this series (41% of all devices). During a follow-up period of 1 to 108 months (mean 36 ± 17 months), a thrombus formation was detect- ed in 20 of 1,000 (2%) patients. The TOE had been performed four weeks and six months after closure in 71% of the patients. Of the 20 patients with docu- mented thrombus formation, 17 had good outcomes with the disappearance of the thrombus following anticoagulation therapy with heparin (n=1), warfarin (n=12), or both (n=4). In three patients the thrombus was removed surgically. Coagulation disorders such as protein C and protein S deficiency and activated protein C resistance were not identified in the throm- bus cases, and hyperactivity of factor VIII and throm- bocytosis was found in two patients. A wire device frame fracture was also observed in 3 of the 20 (15%)
thrombus patients. The authors related atrial septal aneurysm (n=4) and post-procedural paroxysmal atri- al fibrillation (n=4) as significant predictors for throm- bus formation.
Other hypotheses for this late complication could be incomplete endothelialization of the device. Nguyen et al. [16] described one case of very late en- docarditis after twelve years of an ASD closure. The surgical findings showed incomplete endothelializa- tion of approximately one quarter of the Amplatzer Septal Occluder, and vegetations on both sides of the device. The authors commented that although in pre- liminary animal studies of transcatheter ASD closure investigators have reported complete endothelializa- tion within weeks after implantation and a 100% clo- sure rate at 3 months, in humans investigators have observed varying degrees of endothelialization with or without late sequelae. For this setting, investiga- tors have been analyzing surface modifications and coatings on NiTi alloys at the molecular level to en- hance device healing and endothelialization [17, 18].
Conclusions
Transcatheter ASD closure is a common and wide- spread procedure. However, very late complications may occur. Despite very rare, late thrombosis can be a potentially catastrophic event. Candidates for de- vice implantation should be carefully screened for potential thrombotic and allergic conditions prior to choosing the ideal therapy. Close follow-up shall be mandatory in these patients.
Conflict of Interest
The authors have no conflict of interest relevant to this publication.
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References
1. Costa RN, Ribeiro MS, Pereira FL, Pedra SRF, 2. Jatene MB, Jatene IB, et al. Percutaneous versus surgical closure of atrial septal de- fects in children and adolescents. Arq Bras Cardiol. 2013;100:347-354. DOI: 10.5935/ abc.20130059
Butera G, Carminati M, Chessa M, Youssef R, Drago M, Giamberti A, et al. Percutaneous versus surgical closure of secundum atri- al defect: comparison of early results and complications. Am Heart J. 2006;151:228- 234. DOI: 10.1016/j.ahj.2005.02.051
3. King TD, Mills NL. Secundum atrial septal defects: non-operative closure during cardiac catheterization. JAMA. 1976;235:2506-2509. DOI: 10.1001/ jama.1976.03260490024013
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Journal of Structural Heart Disease, December 2019
Volume 5, Issue 6:263-267