The frozen elephant trunk technique in an emergency: THORAFLEX French National Registry offers new insights

OBJECTIVES: Our goal was to study the immediate outcome after an emergency frozen elephant trunk procedure with a Thoraflex (TM) Hybrid prosthesis (THP) in patients included in the EPI-Flex national registry and operated on in 21 French centres. METHODS: All patients operated on in France between April 2016 and April 2019 for acute aortic syndromes and who had an frozen elephant trunk procedure with a THP were included in the study. The main end point was in-hospital mortality. The secondary end point neuromorbidity, including paraplegia. The evolution of the main end point was monitored using a variable life-adjusted display graph with cumulative sum derivatives in order to stop inclusions in case the observed mortality became out of range compared to an expected mortality between 15% and 20%. RESULTS: Enrolment ended on the scheduled date and included 109 patients. Most cases (54%) were performed at 3 centres, where more than 10 THP each were implanted (10-26). The observed mortality in the large-volume centres (22%) was comparable to that observed in the low-volume centres (20%). The individually risk-adjusted cumulative sum revealed that observed in-hospital mortality was statistically in line with that predicted by the log EuroSCORE. Analysis of the secondary end point revealed 8% cases of paraplegia, all of which appeared after treatment of the thoracic type A aortic dissection. CONCLUSIONS: In France, THP for emergency frozen elephant trunk surgery outside high-volume centres did not result in excessive inhospital deaths. However, a word of caution must be expressed regarding the prevention of medullar ischaemia even in emergency aortic surgery.