Zone 0 frozen elephant trunk for type A retrograde acute aortic dissection following endovascular stenting of the arch

Abstract

A 70‐year‐old man underwent the frozen elephant trunk (FET) procedure with zone 0 debranching following a failed endovascular repair for type B aortic dissection and a stent‐graft deployment in zone 1 for a retrograde type A aortic dissection. Zone 0 deployment is a novel approach that is valuable as a bailout strategy in urgent cases and it can potentially improve the technical feasibility of the FET while minimizing its ischemic complications.

Aortic proximalization—Zone 0 versus Zone 2: A concept or true challenge?

“…It is clear that Z‐2‐FET currently represents an efficacious, robust approach to treating Type A AAD and other structural aortic arch pathologies. Indeed, recent data from novel trials investigating Z‐0‐FET are promising and seem to suggest that proximalization of the distal anastomosis not only improves surgical access (thereby shortening CPB, ACP, and HCA time) but also is associated with improved mortality rates and lower incidence of SCI, cerebral injury, RLN injury, renal injury, and visceral ischemia 16–18 . This said, it should be recalled that efficacy of Z‐0‐FET in terms of FL obliteration and postoperative TL integrity is varied 16 .…”

“…Indeed, the difficulty in accessing the proximal DTA via midline sternotomy should not be understated. This would have the added benefit of reducing overall surgical trauma, the overall duration of the procedure, and hence the time spent under CPB, ACP, and HCA—factors which are well‐documented indicators of poor postoperative prognosis 18 . Indeed, Yamamoto et al 16 and Jakob et al 11 highlight the mean CPB duration for Z‐0‐FET as being 184 (±34) min and 176 (±39) min, respectively, compared with 262 (±84) min and 254 (±52) min reported for Z‐2‐FET by Beckmann et al 12 and Jakob et al 11 Similarly, HCA duration for Z‐0‐FET is cited as being around 47 (±7) min, compared with up to 126 (±43) min for Z‐2‐FET 11,16 .…”

“…This discrepancy may be due, in part, to proximalization of the stent graft. Leontyev et al 26 identify distal landing zones as a major risk factor for SCI, and indeed Jiang et al 18 notes that decreased occlusion of the intercostal vessels in Z‐0‐FET may protect against SCI. Rezaei et al 1 also highlight the use of FET stents longer than 15 cm, or extending beyond T8, as risk factors for SCI, and that stent length less than 10 cm may decrease the risk of SCI.…”

“…Rezaei et al 1 also highlight the use of FET stents longer than 15 cm, or extending beyond T8, as risk factors for SCI, and that stent length less than 10 cm may decrease the risk of SCI. Jiang et al 18 further recommends performing FET arch repair with visceral perfusion at moderate hypothermia (28°C) to reduce overall HCA duration and attenuate risk of SCI. Additionally, Yamamoto et al 16 suggest that selective LSA perfusion could improve intraoperative spinal cord perfusion via collateral vasculature during HCA.…”

“…Proponents of zone 0 aortic arch repair argue that the proximalization of the surgical field not only improves the surgeon's access to the sites of anastomosis but also decreases risk of damaging the recurrent laryngeal nerve (RLN), which loops under the aortic arch in close proximity to Zones 2 and 3 18,29 . Indeed, Leone et al 18 concluded that proximalization of arch repair from Zone 3 to Zone 2 reduces the risk of RLN injury from 11% to 2.8%, while Jakob et al 23 argue that Z‐2‐FET effectively eliminates this risk. It is therefore unsurprising that following Z‐0‐FET, Yamamoto et al 16 reported only a single incidence of vocal cord paralysis resulting from RLN injury.…”