Key Words
Iatrogenic aortic dissection - Percutaneous coronary intervention
Introduction
Iatrogenic aortic dissection (IAD) is a rare complication of percutaneous coronary
intervention (PCI)[1]
[2]
[3]
[4]. In contrast to spontaneous Type-A aortic dissection (AD), where emergent surgical
intervention is recommended to avoid devastating sequelae, the optimal management
for IAD is less clear. While initial studies reported a 50% early mortality following
surgical management of IAD, recent registry data suggest that mortality is comparable
to that of spontaneous ADs (16% for IAD vs. 17% for spontaneous AD)[3]
[4]. Patients with IAD are typically older compared to patients with spontaneous AD
but are usually diagnosed immediately and thus require less extensive surgery. Herein,
we present a case of successful conservative management of IAD following PCI extending
from the right coronary artery (RCA) into the aortic root and arch.
Case Presentation
A 50-year-old otherwise healthy female smoker presented at the emergency department
with a 2-day history of gastric reflux-like symptoms. An electrocardiogram revealed
ST segment elevation in the inferior leads. The patient was therefore transferred
immediately for a coronary angiogram. A right radial approach was utilized and showed
normal left main and left anterior descending arteries and a circumflex with a 70%
obtuse marginal lesion. The RCA had a 99% occlusive thrombus with distal TIMI (Thrombolysis
in Myocardial Infarction) 2 flow. A wire was passed to yield a proximal RCA dissection
that involved the entire length of the vessel. Three drug-eluting stents were deployed,
resulting in TIMI 3 flow; however, the dissection had extended retrogradely into the
aortic root and arch ([Figure 1A, B, C]). Furthermore, the dissection flap itself was not covered, demonstrating persistent
communication with the false lumen. Emergent computed tomography (CT) confirmed the
diagnosis of IAD, and the patient was then transferred to our hospital for further
management. She remained pain-free and hemodynamically stable throughout the assessment
and transfer.
Figure 1. Coronary angiogram. Right coronary artery iatrogenic dissection (Panel A, arrows) with contrast into the false lumen in the aortic root (Panel B, arrows) and ascending aorta (Panel C). Chest computed tomography confirmed a dissection in the ascending aorta (Panel D, false lumen, white*; true lumen, black*) and aortic arch (Panel E, false lumen, white*; true lumen, black*).
On arrival, repeat CT scan demonstrated a stable dissection with no active extravasation
into the false lumen, no pericardial effusion, and no aortic insufficiency ([Figure 1D, E]). The patient received a labetalol infusion to target a systolic blood pressure
<120 mm Hg, and aspirin and ticagrelor therapy was continued. Another CT scan the
following morning demonstrated a decrease in the size of the false lumen from 11 mm
to 7 mm at the sinus of Valsalva and no evidence of contrast enhancement in the false
lumen. A dissection flap was noted to extend across the RCA ostium, but the flap did
not limit blood flow. The patient was discharged on day 3 with orders for ramipril,
bisoprolol, and clonidine, as well as dual antiplatelet therapy. At the 2- and 4-month
clinical follow-up visits, the patient remained asymptomatic. The 4-month CT scan
showed complete resolution of the dissection with a patent RCA ([Figure 2]).
Figure 2. Chest computed tomography revealed complete resolution of the dissection in the sagittal
(Panel A) and axial (Panel B) views 4 months after the initial acute dissection event.
Discussion
IAD is a rare complication of PCI with an estimated incidence of 0.02% to 0.06%[1]. Patients with IAD are often older than those with spontaneous AD[1]
[2]
[3]. The RCA is commonly the site of IAD. Dunning et al. classified IAD based on extent
of dissection: Class I dissections involve the ipsilateral aortic cusp, Class II dissections
involve the ipsilateral cusp with extension of <40 mm up the aorta, and Class III
dissections involve the ipsilateral cusp with extension of >40 mm up the aorta. These
authors advocated for coronary stent therapy for Class I and II IAD, and surgery for
Class III IAD[2]; however, these recommendations were based on a limited series of patients, and
the outcome of conservative management for Class III IAD was not evaluated. More recently,
data from the Registry on Aortic Iatrogenic Dissection (RAID) was found to support
conservative management of IAD, although the majority (77%) of cases had limited dissections
(Dunning I and II), and more than half (35 of 74 patients) used stents to cover the
intimal tear[1].
Our patient had an extensive dissection (Dunning class III) that extended into the
aortic arch with a coronary dissection tear that was not covered. While there are
no clear guidelines for IAD management, Dunning et al. advocated for surgical management
for such class III dissections[2]. Nonetheless, we elected to pursue conservative management due to the absence of
evidence of active contrast extravasation into the false lumen on a CT scan hours
after the dissection occurred, as well as some resolution on the predischarge CT.
Importantly, considerable dissection into the aortic root, aortic insufficiency, and
hemopericardium are general indications for urgent surgical intervention; however,
none of these conditions were observed in our patient. Furthermore, persistent active
extravasation of blood into the false lumen on serial imaging would also prompt urgent
surgery, but this condition was not observed in our patient. This case suggests that
conservative management with serial imaging, aggressive blood pressure control, and
close follow-up may be a reasonable approach for select IAD cases.
