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Harky et al. Vessel Plus 2018;2:8 I http://dx.doi.org/10.20517/2574-1209.2018.12 Page 5 of 7

effect of fluctuated blood pressure during repair [26,27] . The current paraplegia rate following TEVAR is around
[28]
[16]
2%-6% in contrary to OR that has a 8.7% rate . This rate in TEVAR can go as high as 15% depending
on the presence of many cofounding factors such as hypotension, concomitant repair of abdominal aortic
aneurysm, long standing aortic disease and renal failure [25,27,28] .

Although the current trend in managing patients with rDTAA is shifting towards TEVAR, the experience
is limited to case series and based on centers of excellence and the presence of experienced operators.
Nevertheless, the studies are confined to short-term outcomes. There is a lack of data related to long-term
outcomes, on the contrary to OR, where the evidence behind its success and long-term outcomes has been
well reported in literature. The surge in using TEVAR is pushed forward by the satisfactory short-term
outcomes in TEVAR itself, providing lower morbidity and mortality rates when compared with OR [7,16,23] .

[18]
In a meta-analysis by Jonker et al. , they have identified that the mortality rate is much lower in TEVAR
group than OR, 18.9% vs. 33.3% respectively (P = 0.16), whilst the stroke rate is reported to be higher in OR
than TEVAR (10.2% vs. 4.1% respectively), however this is not statistically significant (P = 0.11). Similarly, the
paraplegia rate was higher in OR than TEVAR (5.5% vs. 3.1%), yet this is also not statistically significant (P
= 0.40). Whilst vascular complications were higher in the TEVAR group than OR (9.1% vs. 2.3%, P = 0.17),
interestingly, the survival rate from aneurysm related complications was 70.6% in TEVAR patients compared
with 100% in the OR patients.

Despite the success of TEVAR, it carries many limitations. A key consideration in patients undergoing
[29]
TEVAR is the rate of re-intervention. A study by Desai et al. has reported a survival rate of TEVAR
[21]
equivalent to OR in patients with rDTAA at 8-10 years of follow up. In a later study by Botsios et al. , the
rate of re-intervention is thought to be between 4.5%-16% at 1.5-44 months follow up time. Interestingly this
rate reported to be as high as 45.5% after rDTAA in some other studies [6,18] . Such re-interventions can be very
drastic and require further major intervention and hence affect the long-term outcomes overall. Another
limitation of TEVAR is the rate of graft infection, although rare, it is associated with a high mortality rate of
[30]
up to 50% and often requires surgical intervention for definitive management .

Moreover, current vascular surgery practice guidelines suggest considering several factors prior to TEVAR
in patients presenting with rDTAA. These factors include anatomical consideration, surgical urgency and the
[18]
presence of surgical expertise to perform the procedure .
At this current stage, there is no randomized controlled trial found to provide comparative clinical outcomes
and cost effectiveness comparison between OR and TEVAR in patients presenting with rDTAA. Therefore,
[3]
the choice of procedure in these patients is based on the experience of the center and the operator .

CONCLUSION
TEVAR serves a feasible and attractive option for patients presenting with rDTAA. It is being used in many
centers as the first line management of such acutely unwell patients, primarily due to its promising short-
term outcomes. However, the published data behind this recommendation is limited and is composed of
only case series with retrospective observational studies and lacks any randomized data trials. Regular
follow up of patients that undergo a TEVAR is required for early identification and management of TEVAR-
related complications such as endoleaks.

DECLARATIONS
Authors’ contributions
Design: Harky A, Chan JSK, Wong CHM