Does only the proximal descending aorta influence aortic dilatation after repair of the aortic dissection?

Abstract

We congratulate Kim et al. for their study [1]. They highlight the significance of adjunctive procedures to the proximal descending aorta in preventing late aneurysm formation following repair of acute type I aortic dissection. In their study, the diameter of the proximal descending aorta at presentation was a predictive factor for future aneurysm formation. Aneurysmal dilation of the proximal descending aorta was almost 80% at 8-year follow-up. We agree with the authors that the proximal descending aorta is the major site for postoperative aortic aneurysm, thus stabilizing this aortic segment with appropriate-length stent grafting might prevent aneurysm formation. Graft coverage (15 cm) has not been shown to lead to significant paraplegia risk when treating acute dissection [2]. Use of a hybrid operating theatre in the treatment of DeBakey I dissection may be useful to achieve the best and safest results. Although total circulatory arrest time may be longer in the frozen elephant trunk procedure, postoperative stroke rates have not been impacted adversely [2]. The frozen elephant trunk procedure not only eliminates the dissected aortic wall, but may also facilitate the repair of the arch and descending aorta with lesser perioperative complications [3]. In the follow-up period of the frozen elephant trunk procedure, complete thrombosis of the false lumen in the peri-graft area, the distal thoracic and the abdominal aorta were reported to be 92, 48 and 6%, respectively [4]. Conversely, the performance of total arch replacement at the time of acute dissection without the frozen elephant trunk has not been shown to decrease the risk of aortic aneurysms in the long term, but does increase operative mortality. To minimize operative risks, we recommend the frozen elephant trunk procedure be added to hemi-arch replacement. Total arch replacement should be done only in technically non-repairable arches. In conclusion, it is a valuable study. The readers thank the authors for sharing their experience. We agree with the authors' advice to stabilize the proximal descending aortic segment in all cases. Our technique favours the use of at least 15-cm stent grafts onto the thoracic aorta to achieve false lumen obliteration while only performing a hemi-arch replacement rather than total arches to minimize upfront mortality.