Introduction
Utilizing ”elephant trunk” (ET) prosthesis first described by Borst et al. in 1986 for aneurysmal aortic disease revolutionized treatment strategies in managing patients with complex arch and descending aorta pathologies (1). Antegrade open stent-grafting of the descending aorta described in 1996 became the cornerstone of further advancement in the arch and proximal descending aorta (2). In the early 2000s, a custom-made hybrid prosthesis called frozen elephant trunk (FET) had been developed (3). Subsequently, the FET technique has been extensively engaged in various acute and chronic pathologies of the thoracic aorta.
Replacement of the ascending aorta is a well-researched conventional treatment of acute Type A aortic dissection (ATAAD); however, residual pathology or dissection in the arch or downstream descending aorta may require additional treatment with high-risk redo procedures. On the other hand, more extensive aorta replacement (e.g., employing FET) carries the risk of complications. Therefore, there is still an ongoing debate over the optimal indication and FET use in ATAAD. One of the main complications associated with FET is neurologic events, particularly spinal cord injury (SCI) and stroke. The incidence rate of permanent or transient ischemic SCI after conventional ET has been reported between 0.4% and 2.8% in previous reports (4).
In contrast, the incidence of SCI after FET ranged between 8% in multicenter studies (5) and 20% in single-center reports (6). Several contributors (i.e., length of the device and distal circulatory arrest time) have been proposed to explain SCI and stroke observed after FET procedure, mainly derived from observational studies on patients with diverse aortic pathologies. Previous meta-analyses performed on primary studies included a mixture of cohorts diagnosed with acute or chronic dissection which differ in various aspect of treatment options and also comorbid diseases (7). Herein, we evaluated the pre-and intra-operative characteristics of patients with ATAAD undergoing the FET procedure and their associations with postoperative outcomes.