Patent foramen ovale and paradoxical embolization: a historical perspective.

The use of transesophageal echocardiography for intraoperative management of critically ill patients allows for routine evaluation of foramen ovale patency. The high prevalence of preoperatively unrecognized flow-patency of this structure has led investigators to emphasize the potential for paradoxical embolization in any patient undergoing anesthesia. This perspective led us to research earliest documentation of paradoxical embolization through a patent foramen ovale as a historical issue with present day relevance. This report examines the 1877 text of Julius Cohnheim in which he described a fatal case of paradoxical embolization to the middle meningeal artery. The 1880 manuscript of Moritz Litten documenting paradoxical embolization to the lower extremity is also presented. Both translations, to our knowledge, represent the first such representations of both the original 1877 edition of Cohnheim's work and Litten's journal article.