Objective: To describe our experience with endovascular stent-graft repairs in type B aortic dissection focusing on serious secondary complications resulting in immediate or late conversion to open repair. Methods: From November 1997 to May 2007, 28 patients underwent a thoracic endovascular stent-graft procedure for acute symptomatic type B dissection at our institution. Indication for endovascular repair at our department is a complicated course of type B dissection, including thoracic aortic rupture, suspicion of impending rupture, visceral. and/or peripheral ischemia, uncontrollable hypertension, and severe therapy-resistant pain. Median follow-up time was 48.3 months (range 2-97 months). Results: Secondary complications with indication for a secondary intervention occurred in 5/28 patients, resulting in additional procedures in 4 patients. One patient declined any further therapy. Conversion to an open procedure was performed in four patients, one due to type I endoleak followed by retrograde type A dissection, and three due to retrograde type A dissection. One of these patients had an additional stent-graft procedure performed due to a type III endoleak 20 months post stent grafting. Retrograde type A dissection occurred 39 months later, finally leading to conversion to an open procedure. Open surgery was performed in four patients after 3, 26, 29, and 1170 days post stent-graft placement and was successful in three patients. The fourth patient died 3 months post-surgically due to multi-organ failure. The procedure-related mortality rate following secondary complications was (1/5) 20%. Conclusions: Endovascular stent-graft repair of the thoracic aorta is an alternative to surgical repair, however not without significant morbidity and mortality. Potentially lethal complications, acute or delayed, may occur. (C) 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.