Page 27 - Read Online

Page 6 of 13 Jubouri et al. Vessel Plus 2023;7:5 https://dx.doi.org/10.20517/2574-1209.2022.49

characteristics who are not suitable candidates for OSR. Those high-risk patients may benefit from an
[35]
alternative endovascular approach that circumvents the hazards that come with CPB and HCA . The
decision of whether a patient is eligible or not for OSR is usually made after multidisciplinary evaluation on
an individualized basis. Some high-risk features are well-established in the literature, such as older age
(≥ 75 years), which was shown to independently and significantly predict perioperative mortality and
adverse events following OSR [36,37] .

Besides, the use of risk prediction tools such as the American Society of Anesthesiologists (ASA)
Classification and the EuroSCORE has been employed in inferring patients’ risk and determining eligibility
for OSR in patients with arch disease [30,38] . Spear et al. used a multidisciplinary evaluation and an ASA III/IV
[38]
to deem patients unfit for surgery . In their report, they further specified the eligibility criteria to include a
negative cardiac stress test, no Class III/IV heart failure, no stroke or myocardial infarction in the last year,
no significant carotid stenosis, and GFR 45 mL/min/1.73 m . All these factors and more are considered in
2[38]
the risk stratification of patients with aortic arch disease. However, the breadth of aortic arch pathologies
and associated comorbidities makes it hard to certainly stratify patients with high risks. Thus, a
multidisciplinary evaluation remains the best approach to determining eligibility.

In patients with high-risk profiles for OSR, a set of morphological and disease features can determine
patient eligibility for TER. Initially, for stable implantation of the endograft, an adequate landing zone is
pre-determined based on parameters from preoperative imaging. These parameters include (i) a sealing
zone within the ascending aorta (zone 0) less than 38 mm in diameter; and (ii) a sealing zone of at least
40 mm in length in the ascending aorta or the primary entry tear is not within 20 mm of the sino-tubular
junction [30,38] . Table 2 highlights detailed and specific anatomic criteria as summarized by Czerny and
colleagues. Figure 3 illustrates the algorithm flowchart for determining patients’ eligibility for TER.

As is the case with any procedure, TEVAR is associated with a significant learning curve that is reflected in
the flow of the procedure as well as patient outcomes. This is evident in the retrospective single-centre study
of TEVAR by Tan et al., which showed that there was a learning curve involved reflected by higher than
average mean operative time, average radiation dose and mean contrast volume used during their initial
[39]
experience .

Clinical outcomes
An appraisal of endovascular repair for aortic arch pathology requires analysis of the clinical outcomes
associated therewith. Despite the minimally-invasive nature of TER providing an obvious advantage over
OSR in certain cases, TER remains associated with comparable mortality rates and key complications such
as technical failure, neurological injury, need for reintervention, and loss of or failure to achieve target vessel
patency (TVP) . These are standard metrics used to gauge the efficacy of surgical intervention on the
[40]
aortic arch, and represent key challenges to the widespread adoption of TER as the gold-standard
intervention for aortic arch pathologies in specific patient groups.

Technical success and target vessel patency
In the context of TER for aortic arch pathology, technical success can be defined as successful endovascular
stabilisation of the aortic arch and the subsequent maintenance of aortic arch (as well as arch vessel)
patency during follow-up . Singh et al., in their evaluation of the RELAY™ Branched endoprosthesis in 148
[40]
patients undergoing TER between January 2019 and January 2022, reported a 99.3% (n = 147) success
rate . TVP was achieved in all patients and maintained during the initial 30 days postoperative. After 24
[40]
months of follow-up, an overall of 118 patients (80.2%) exhibited TVP. This included 80 (74%) patients in