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

Abstract

Background The use of the Frozen Elephant Trunk (FET) device to manage complex surgical pathologies of the aorta (such as acute type A aortic dissection) has gained popularity since its introduction in the early 2000s. Though the distal anastomosis was traditionally performed at aortic Zone 3 (Z‐3‐FET), preference gradually shifted towards Zone 2 (Z‐2‐FET) in favor of improved surgical access and clinical outcomes. This review seeks to elucidate whether proximalization of arch repair to Zone 0 (Z‐0‐FET) would further improve postoperative outcomes. Methods We performed a review of available literature to evaluate the comparative efficacies of Z‐2‐FET versus Z‐0‐FET, in terms of surgical technique, clinical outcomes, and incidence of adverse events. Results Z‐0‐FET seems to be associated with a more accessible surgical approach, and shorter cardiopulmonary bypass, antegrade cerebral perfusion, and cardioplegia durations than Z‐2‐FET. Further, Z‐0‐FET is could potentially be associated with a lower incidence of neurological, renal, and recurrent laryngeal nerve injury, as well as mortality and reintervention rates than Z‐2‐FET. This said, Z‐0‐FET is itself associated with significant challenges, and efficacy in terms of postoperative true lumen integrity and false lumen thrombosis is mixed. Conclusion Current literature seems to suggest that Z‐0‐FET procedures are more straightforward and associated with lower rates of certain adverse events, however, the majority of data reviewed is retrospective. This review, therefore, recommends prospective research into the comparative strengths and limitations of Z‐0‐FET and Z‐2‐FET to better substantiate whether proximalization of arch repair represents a concept, or a true challenge to advance surgical intervention for arch pathologies.

Correlation of coagulopathy and frozen elephant trunk use in aortic arch surgery: A systematic review and meta‐analysis

“…Indeed, there exists robust data on the relationship between neurological outcome and FET graft sizing. For example, Preventza et al report that stent lengths below 10 cm carried a lower risk of spinal cord injury, and Tan et al suggest that proximalisation of TAR to Zone 0 may be associated with improved neurological outcomes 65,66 . Undoubtedly, a similarly nuanced appreciation of coagulopathy predictors associated with different FET devices and sizes would be of great benefit.…”

“…report that stent lengths below 10 cm carried a lower risk of spinal cord injury, and Tan et al suggest that proximalisation of TAR to Zone 0 may be associated with improved neurological outcomes. 65,66 Undoubtedly, a similarly nuanced appreciation of coagulopathy predictors associated with different FET devices and sizes would be of great benefit. This would facilitate a more holistic understanding of the risks and benefits associated with each individual procedure and allow a more nuanced evaluation of patient-specific needs and risks.…”

Frozen Elephant Trunk Sizing: A 30,000-Feet Perspective with Thoraflex Hybrid Stent Graft

“…The surgical approach and perioperative management for TAR with Thoraflex HP have been reported in the literature with some consensus among the aorto-vascular community. 4 5 6 …”

“…Hypothermic circulatory arrest is established, with myocardial protection maintained via cold crystalloid or cold blood cardioplegia. 4 Adjunctive cerebral perfusion may be provided via retrograde cerebral routes or antegrade cerebral routes. 6 7 Under circulatory arrest, the diseased portion of the arch is resected, allowing inspection of the remaining DTA and identification of the TL and FL (aided by the femoral guidewire).…”

“… 5 Once a graft size is selected, the graft is introduced antegrade into the DTA over the guidewire, and distal arch anastomosis is performed between the graft collar and the native aortic wall. 4 Thoraflex HP features a fourth branch allowing lower body perfusion to resume following the distal anastomosis. 2 However, in devices without this advantageous feature (such as E-vita Open Plus), a Foley catheter can be positioned in the stent graft to provide distal perfusion.…”