Keywords ascending aorta - TEVAR - stent grafting - landing zone
Introduction
Open surgery is the gold standard for treatment of ascending aortic disease. However,
it is sometimes chosen due to a lack of minimally invasive options. Thoracic endovascular
aortic repair (TEVAR) for the treatment of ascending aortic pathology has been used
selectively since it was first described in 2000.[1 ] Here, we report the successful treatment of a Zone 0 penetrating aortic ulcer (PAU)
utilizing stent-graft deployment.
Case Presentation
A 77-year-old man established care with our service for follow-up of a known ascending
aortic PAU after relocating from another state. Reportedly, the PAU had measured 4.2 cm
in 2017 and had increased to 5 cm prior to relocation. At presentation to our department,
the patient denied chest pain and had a history of hypertension controlled with medication.
Repeat imaging showed saccular aneurysmal dilation of the ascending aorta measuring
up to 5.7 × 4.5 cm. The saccular component of the PAU itself was 3.4 cm in diameter
([Fig. 1 ]). He had no history of coronary disease, no significant coronary calcification on
computed tomography angiography (CTA), no aortic valve disease, and an ejection fraction
of 55% on echocardiography. Based on the rapid increase in size and characteristics
of his PAU, intervention was indicated. Proximal and distal areas in Zone 0 showed
adequate landing zones for a standard TEVAR graft. Based on his imaging, age, and
functional limitations, the patient qualified for either an open or endovascular procedure.
Both options were discussed at length with the patient, who expressed a preference
for TEVAR. The case was discussed in multidisciplinary forum, which included cardiothoracic
surgery, structural interventional cardiology, and interventional radiology, with
consensus for feasibility of TEVAR.
Fig. 1 Preoperative axial (A ) and 3D-reconstruction (B ) Computed tomography angiography images demonstrating ascending aortic penetrating
ulcer (arrows ). Curved planar reformats with corresponding measurements of average proximal (C ) and distal (D ) landing zone diameters are also shown.
The procedure was performed in a hybrid operative suite with all multidisciplinary
teams present and a cardiac anesthesiologist. With the patient under general anesthesia,
ultrasound guided access was obtained in the right radial, right common femoral, and
left common femoral arteries (CFA). The so called “preclose” technique with Proglide
vascular closure devices (Abbott Laboratories, North Plymouth, MN) was employed at
the right femoral access. Coronary angiography was performed via right radial access
to mark the level of the coronary arteries. The heights of the coronary arteries were
low, embedded in the aortic valve, with ample room for proximal stent deployment.
Coronary disease was seen, which had not been delineated on preoperative CTA. The
patient had 100% occlusion of the left anterior descending artery (LAD), mitigated
by brisk refill through collateralization. He also had a high-grade lesion of the
midcircumflex artery (80% occlusion). Given the absence of angina and adequate collateral
flow, no coronary intervention was felt to be indicated.
The right CFA access was serially dilated to accommodate a 24-Fr Gore DrySeal introducer
sheath (W.L. Gore & Associates, Flagstaff, AZ). The ascending aorta was catheterized
with a pigtail flush catheter advanced from left CFA access. The image intensifier
was placed in left-anterior-oblique angulation. Arch aortogram showed the penetrating
ulcer in Zone 0. The origins of the great vessels were in standard configuration and
widely patent. From right CFA access, a pigtail was advanced through the aortic valve,
and a Lunderquist wire (Cook Medical, Bloomington, IN) was advanced into the left
ventricle and used for cardiac pacing. A conformable-TAG (W.L. Gore & Associates,
Flagstaff, AZ) 45 mm × 45 mm × 10 cm was passed from the right groin and positioned
with seal on either side of the PAU. The device was deployed and seated during a brief
period of rapid ventricular pacing, with no migration. Subsequent aortogram showed
no evidence of endoleak and complete exclusion of the ulcer. The origins of the great
vessels were preserved, and placement was above the aortic valve and coronaries ([Fig. 2 ]). Hemostasis was achieved with the “preclose” technique. Pedal pulses were unchanged
at the end of the case. The patient was extubated, neurologically intact, and transferred
to the intensive care unit. CTA after 1 month demonstrated appropriate graft placement
without evidence of leak ([Fig. 3 ]).
Fig. 2 Intraoperative angiogram prior to (A ) and following (B ) deployment of stent-graft in the ascending aorta. Final positioning is also shown
(C ).
Fig. 3 Computed tomography angiography 1 month postoperatively: appropriate graft placement
(arrows ) without evidence of leak.
Discussion
TEVAR has been safely and effectively used in descending aortic disease for years.[2 ] In selected cases, standard TEVAR grafts have been employed in the management of
ascending aortic disease; there is enthusiasm for an endovascular approach to Zone
0 disease with approved branched grafts and others on the horizon.[3 ]
[4 ]
[5 ]
[6 ]
[7 ] The gold standard for treating Zone 0, which includes the sinotubular junction,
ascending aorta, and base of arch vessels, remains open surgery. Endovascular approaches
face multiple challenges. They require suitable landing zones, adequate aortic diameter,
and careful stent-graft selection and deployment and are threatened by the increased
shear stress within the ascending aorta, which can result in device migration.[5 ] Because of the significance of regional anatomy, our program has elected to incorporate
an Aortic “Zone 0 team” including cardiothoracic surgery, structural interventional
cardiology, and interventional radiology to assess adequacy of TEVAR, appropriate
diagnosis, and preparations for potential pitfalls during the procedure. In our patient,
the positioning of coronary orifices coupled with ample proximal and distal landing
zones dictated that a standard graft could be used without occluding the coronary
arteries or aortic arch vessels. To mitigate concerns over device migration, we opted
to utilize rapid ventricular pacing during deployment. As seen on postoperative CTA,
the device has remained in place with no signs of dissection or migration after 1
month.
Proper imaging of the aorta and careful determination of suitable landing zones are
key for patient selection and operative planning. Graft selection is also critical,
since problems can arise secondary to aortic curvature, the distance between the sinotubular
junction and innominate artery, and the coronary artery orifices. Currently, there
are no Food and Drug Administration-approved devices for use in the ascending aorta.
However, multiple techniques, including physician modified grafts, chimney or periscope
techniques, in situ fenestration, fenestrated grafts, and branched grafts have met
with some success.[3 ]
[4 ]
[5 ] There are also several novel devices under development. One dedicated stent-graft
for the ascending aorta (Zenith Ascend TAA Endovascular Graft, William Cook Europe,
Bjaeverskov, Denmark) has shown promising early results in selected high-risk patients,[6 ] and a second designed for the aortic arch (Terumo RelayBranch, Terumo Aortic, Sunrise,
FL) is undergoing feasibility studies in the United States.[7 ]
One of the potentially life-threatening complications after TEVAR is Type A aortic
dissection. While the precise mechanism remains a topic of debate, studies have identified
an association with proximal landing zone, particularly Zone 0.[8 ] Proximal stent-graft configuration and oversizing have also been identified as potential
contributors.[8 ] As the number of Zone 0 cases being performed endovascularly increases, additional
research is critical to developing an in-depth understanding of the associated risks,
allowing surgeons to better guide their patients in decision-making.
TEVAR for ascending aortic pathology can be safely and successfully performed. In
anatomically amenable cases and with appropriate graft selection, TEVAR for selected
Zone 0 aortic pathologies is an appropriate choice of therapy for patients utilizing
a Zone 0 aortic team approach. However, further study is still needed, especially
as specialized devices are developed and additional outcomes data become available.
