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.