Neurologic complications after the frozen elephant trunk procedure: A meta-analysis of more than 3,000 patients

Abstract Objective The frozen elephant trunk (FET) technique's safety regarding spinal cord ischemia (SCI) has been questioned. We used meta-analysis to determine rates of adverse neurologic events and mortality. Methods We searched PubMed/Medline, Embase, Scopus, and Cochrane databases (inception–April 2018) to identify studies of post-FET neurologic events. Separate meta-analyses were conducted with random-effects models to assess FET's associations with SCI, stroke, operative mortality, and all adverse events combined. Subgroup analyses compared outcomes in patients with acute versus nonacute Type A dissection and aneurysm and with different extents of coverage. Results Thirty-five studies (total N=3154) met inclusion criteria. The pooled rates of the outcomes of interest were 4.7% (95% CI, 3.5%-6.2%) for SCI, 7.6% (95% CI, 5.0%-11.5%) for stroke, and 8.8% (95% CI, 7.0%-10.9%) for operative mortality. The SCI event rate was higher with stent length ≥15 cm or coverage to T8 or beyond than with stent length of 10 cm (11.6% vs 2.5%, P Conclusion As the FET procedure becomes more popular, accurate data regarding outcomes is vital. We associated the FET technique with (non-significantly) more adverse events overall in acute Type A dissection cases. Stent length of 10 cm was associated with significantly less risk of SCI. Using a stent ≥15 cm or coverage extending to T8 or farther should be avoided.