Original article Device-less patent foramen ovale closure by radiofrequency thermal energy NB Walpoth, K Habermacher, S Watson, C Schönenberger DOI: https://doi.org/10.4414/smw.2008.12182 Publication Date: 23.02.2008 Swiss Med Wkly. 2008;138(07-08):108 This text is only available as PDF .