Posterior False Lumen and Paraplegia Following FET Procedure in Acute Type A Aortic Dissection.

BACKGROUND: Postoperative paraplegia is the major concern for frozen elephant trunk (FET) procedure in acute type A aortic dissection (ATAAD) patients. It is crucial to determine patients with high risk of paraplegia before implementing FET procedure.

METHODS: From January 2013 to December 2018, 544 ATAAD patients undergoing FET procedure were included in this study. The segment number of posterior false lumen (PFL) between T9-L2 levels was calculated. In-hospital outcomes and long-term survival were investigated based on the number of PFL.

RESULTS: The average age was 46.5±9.9 years old and the proportion of female was 19.5% in this cohort. The incidence of postoperative paraplegia was significantly increased when PFL was presented in 3 or more segments. Patients were divided into high-PFL (3-6 segments) (n=124) and low-PFL group (0-2 segments) (n=420). The demographic characteristics were similar between the two groups. The involvement of celiac trunk and superior mesenteric artery were significantly lower in the high-PFL group (all P<0.05). The other baseline characteristics and procedural information were statistically balanced. The incidence of postoperative paraplegia was significantly higher in the high-PHL groups (7.3% vs 1.9%, P=0.006). Multivariable logistic analysis revealed that the high-PFL was independently associated with postoperative paraplegia following FET procedure (OR=3.812, 95%CI: 1.378-10.550, P=0.010). Additionally, the moderate nasopharyngeal temperature of hypothermic circulatory arrest (≧23.0°C) was clarified as a protective factor for paraplegia (OR=0.112, 95%CI: 0.023-0.535, P=0.006).

CONCLUSIONS: ATAAD patients presenting with High-PFL between T9-L2 levels have significant high risk of postoperative paraplegia if undergoing FET procedure.