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Page 6 of 9 Lou et al. Vessel Plus 2022;6:38 https://dx.doi.org/10.20517/2574-1209.2021.108

the Penn group reported a 30-day postoperative mortality rate of 2.8% at 30 days and relatively low
incidences of other adverse events: 2.8% incidence of permanent renal failure, 2.8% stroke, 5.7% paraparesis,
[18]
and 2.8% paralysis. One-year survival was 93.4% . In another series out of Duke, there were no deaths in
the first 30 days after TEVAR, and similar rates of renal failure, stroke and spinal cord ischemia were
reported . In our previously published analysis of complicated TBAD patients receiving TEVAR at index
[19]
hospitalization, the in-hospital mortality was 5.0% with a 1.3% incidence of renal failure, 7.5% stroke, 2.5%
paraparesis, and 0 cases of paraplegia .
[21]

New frontiers in ATAAD management
The success with TEVAR as highlighted in the previous section on the management of complicated TBAD
has led to endovascular techniques to manage MMP in ATAAD. This approach views end-organ failure as
the most immediate threat to life in relatively stable (i.e., absence of shock//rupture/tamponade) patients in
order to improve survival. TEVAR reverses true lumen compression in the descending and abdominal aorta
due to a dynamic flap and re-establishes flow to the visceral vascular beds as well as affected lower
extremities.

The Michigan group has published their extensive experience with percutaneous interventions to re-
establish end-organ perfusion and delaying operative repair until after the resolution of malperfusion
syndrome. In their initial series, of 196 patients with ATAAD presenting between 1997 and 2007, 70 patients
underwent endovascular fenestration or branch vessel stenting first. Among the 47 patients who survived to
delayed central aortic repair after a median of 4 days, mortality (8.5%) was comparable to that of patients
presenting without malperfusion syndrome . The same group has recently analyzed their 20-year data with
[22]
this strategy . From 1996 to 2017, in 597 patients presenting with ATAAD, 135 patients with malperfusion
[23]
syndrome (visceral or extremity) but without evidence of aortic rupture/tamponade were managed with
endovascular reperfusion upfront (via fenestration/stenting) followed by delayed open aortc repair. In-
hospital mortality improved over the two decades of analysis (from 21.0% to 10.7%, P < 0.001). The authors
reported that 69.5% of patients ultimately underwent delayed open repair and 26.5% died from end-organ
failure prior to delayed open repair. Interestingly, even after the resolution of branch artery obstruction with
fenestration and/or stenting, the likelihood of dying from end-organ failure was 7×’s higher than that of
dying from aortic rupture. The authors thus concluded that it is reasonable to presume that “not every
untreated type A dissection will rupture, but every untreated malperfusion syndrome will result in death” .
[23]
For stable patients with MMP, the risk of aortic rupture is low, and data from Emory also supports that a
TEVAR-first approach with delayed proximal aortic replacement may be the strategy of choice to improve
outcomes. In an institutional analysis of 618 patients presenting with ATAAD from 2003 to 2017 at an
Emory Healthcare facility, 34 patients (5.5%) presented with MMP with mean serum lactate of
4.3 ± 2.1 mmol/L .
[24]
Over the course of the study period, the management strategies for these patients evolved . From 2004 to
[24]
2009, the favored treatment was immediate ascending aortic replacement followed by exploratory
laparotomy, bowel resection, and femoral-femoral bypass as needed (n = 13). From 2009 onwards, some
patients received axillary-bifemoral (Ax-Bifem) bypass prior to sternotomy with perfusion of both the right
axillary artery and Ax-Bifem graft during cardiopulmonary bypass (n = 3). Finally, after 2012, endovascular
techniques began to be integrated into the treatment algorithm using either an antegrade TEVAR (n = 5) or
a TEVAR-first (n = 13) approach. The antegrade TEVAR approach involved obtaining wire access in the
descending aorta and deployment of the endograft under direct vision at the time of open ascending/arch
replacement. The distal end of the ascending/arch Dacron graft was then sewn to the aorta incorporating