Background Use of the Frozen Elephant Trunk (FET) device to manage complex surgical pathologies of the aorta (e.g. acute Type A aortic dissection) has gained popularity since its introduction in the early 2000s. Though the distal anastomosis was traditionally performed at Zone 3 (Z-3-FET), preference gradually shifted towards Zone 2 (Z-2-FET) in favour of improved surgical access and outcomes. This review seeks to elucidate whether proximalisation 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 proximalisation of arch repair represents a concept, or a true challenge to advance surgical intervention for arch pathologies.

Background Aortic Aneurysm (AA) is a common atherosclerotic condition, accounting for nearly 6,000 deaths in England and up to 175,000 deaths globally each year. The pathological outward bulging of the aorta typically results from atherosclerosis or hereditary connective tissue disorders. AAs are usually asymptomatic until spontaneous rupture or detected on incidental screening. 8 in 10 patients do not survive the rupture and die either before reaching hospital or from complications following surgery. Similar to other cardiovascular pathologies (CVPs), AA is thought to be subject to chronobiological patterns of varying incidence. Methods We performed a literature review of the current literature to evaluate the association between circadian rhythms, seasonal variations, and genetic factors and the pathogenesis of AA, reviewing the impact of chronobiology. Results The incidence of AA is found to peak in the early morning (6 AM – 11 AM) and colder months, and conversely troughs towards the evening and warmer months, exhibiting a similar pattern of chronobiological rhythm as other CVPs such as myocardial infarcts, or cerebrovascular strokes. Conclusion Literature suggests there exists a clear relationship between chronobiology and the incidence and pathogenesis of ruptured AA; incidence increases in the morning (6am - 11am), and during colder months (December – January). This is more pronounced in patients with Marfan Syndrome, or vitamin D deficiency. The underlying pathophysiology and implications this has for chronotherapeutics, are also discussed. Our review shows a clear need for further research into the chronotherapeutic approach to preventing ruptured AA in the journey towards precision medicine.

Background: Acute type A aortic dissection (ATAAD), is a surgical emergency often requiring intervention on the aortic root. There is much controversy regarding root management; aggressively pursuing a root replacement, versus more conservative approaches to preserve native structures. Methods: Electronic database search we performed through PubMed, Embase, SCOPUS, google scholar and Cochrane identifying studies that reported on outcomes of surgical repair of ATAAD through either root preservation or replacement. The identified articles focused on short- and long-term mortalities, and rates of re-operation on the aortic root. Results: There remains controversy on replacing or preserving aortic root in ATAAD. Current evidence supports practice of both trends following an extensive decision-making framework, with conflicting series suggesting favourable results with both procedures as the approach that best defines higher survival rates and lower perioperative complications. Yet, the decision to perform either approach remains surgeon decision and bound to the extent of the dissection and tear entries in strong correlation with status of the aortic valve and involvement of coronaries in the dissection. Conclusions: There exists much controversy regarding fate of the aortic root in ATAAD. There are conflicting studies for impact of root replacement on mortality, whilst some study’s report no significant results at all. There is strong evidence regarding risk of re-operation being greater when root is not replaced. Majority of these studies are limited by the single centred, retrospective nature of these small sample sized cohorts, further hindered by potential of treatment bias.