Microvena atrial septal defect occlusion device--update 2000

This article (1) summarizes the Duke University results with the Das-Angel Wings atrial septal defect occlusion device, (2) outlines the rationale for design changes in the device, and (3) describes the new Microvena atrial septal defect occlusion device characteristics, and plans for the future. At Duke University, investigators using the first-generation device attempted closures in 35 patients with atrial level communications. Ages ranged from 5 to 83 years with a median of 28 years, and weights ranged from 16 to 100 kg. Thirty-two of the 35 defects had successful device placement. On follow-up, the defects of 27 of 32 patients with an implanted device were completely closed, and 5 patients had < 2-mm residual leaks. Three patients had malposition of the device, two of whom were treated surgically and one of whom was treated with percutaneous device retrieval. Complications included one small mitral valve perforation with no clinical sequelae. There have been no strokes, delayed embolizations, nor procedure or device related deaths. There have been no new or late problems in the cohort in a follow-up extending to 63 months. Opportunities for improvement of the device were noted during the clinical study. The manufacturer, Microvena Corporation, voluntarily withdrew the occluder for a redesign initiative. The objectives of redesign were ready deployment, reduction of device manipulation, rounding of the device, and retrievability. The Guardian Angel device has been the product of the redesign effort. It is a percutaneously inserted atrial septal defect occlusion device that uses the same materials as the initial device, but which has advantages of retrievability, repositionability, and no need for device manipulation. Initial studies have been performed in experimental animals, and clinical trials are planned for the near future.