Journal of Cardiology Cases 18 (2018) 13–16

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Journal of Cardiology Cases
journal homepage: www.elsevier.com/locate/jccase

Case Report

Two rare cases of congenital aortic stenosis showing a discrepancy
between preoperative imaging diagnosis, intraoperative ﬁndings, andhistopathological diagnosis
Shiro Miura (MD MSc)a,*, Katsumi Inoue (MD PhD)b, Satoshi Yamada (MD PhD FJCC)c,
Takehiro Yamashita (MD PhD)a, Kenji Ando (MD)daDepartment of Cardiology, Hokkaido Ohno Memorial Hospital, Sapporo, JapanLaboratory Medicine, Kokura Memorial Hospital, Kitakyushu, Japan
cDepartment of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, JapandDepartment of Cardiology, Kokura Memorial Hospital, Kitakyushu, Japanb

A R T I C L E I N F O

A B S T R A C T

Article history:
Received 30 October 2017
Received in revised form 19 February 2018
Accepted 7 March 2018

Unicuspid aortic valve (UAV) is an extremely rare congenital heart valve abnormality while bicuspid valve(BAV) has been reported as one of the most common cardiac anomalies. With a UAV usually showing
similar presentations to a BAV, such as aortic regurgitation or aortic stenosis (AS), it is challenging todifferentiate them from each other in clinical settings. Despite some features shared between both valve
disorders, there can be a clinical signiﬁcance in distinguishing UAV from BAV for the management ofpatients with these heart anomalies. Herein, we describe two cases where patients with hemodynamically severe AS were diagnosed with BAV and UAV, respectively based on preoperative examinations andintraoperative ﬁndings, but subsequent pathological examinations conﬁrmed the opposite diagnosis inboth cases.
<Learning objective: Preoperative diagnosis of congenital aortic valve diseases can often be challenging.
There remains a remarkable number of misleading cases. Thus, it is strongly recommended that anaccurate diagnosis should be attempted at the earliest stages of congenital aortic valve disease.
Additionally, both careful follow-ups using multiple imaging modalities and conﬁrmations via
pathological diagnosis for patients undergoing surgery, if they are ﬁrst found to be at an advanced
stage or remain undiagnosed preoperatively are important.>© 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Keywords:
Unicuspid aortic valve
Bicuspid aortic valve
Transesophageal echocardiography
Multislice computed tomography

Introduction
Unicuspid aortic valve (UAV) is a rare congenital heart anomaly
with an estimated frequency of 0.02% among the adult population[1] and often can present as a form of signiﬁcant aortic stenosis(AS) or aortic regurgitation (AR) in symptomatic relatively young
subjects who sometimes require cardiac surgery. Bicuspid aorticvalve (BAV), on the other hand, is one of the most common cardiac
malformations with an estimated incidence of 0.9–2% [2], whichshows similar clinical manifestations to UAVs, as related to valve
dysfunction, and is often accompanied with abnormalities of the* Corresponding author at: Department of Cardiology, Hokkaido Ohno Memorial
Hospital, 2-1-16-1, Miyanosawa, Nishiku, Sapporo, Hokkaido 063-0052, Japan.
E-mail address: s.miura@ohno-kinen.jp (S. Miura).

aorta (aneurysm, dilatation, and dissection) and other cardiac
malformations [3].
Despite some features shared between both valve disorders,
there can be a clinical importance in distinguishing UAV from BAV
for the management of patients with these heart anomalies. Serial
assessments using transthoracic echocardiography (TTE) havedisclosed that valve dysfunctions progress more rapidly in patientswith UAV than those with BAV [4] and that UAV patients are more
likely to develop symptoms at an early age [1]. Regarding theanatomical aspects, Noly et al. [5] demonstrated that there areseveral distinct characteristics between them. The rate of aortic
dilatation was signiﬁcantly lower in UAV than in BAV cases, leading
to a relatively low incidence of acute aortic events in UAV. Incontrast, the aortic annulus was dilated (>25 mm) in most patientswith UAV requiring surgery in 71%. Consequently, preoperative
discrimination of the two is of signiﬁcant importance indetermining an appropriate surgical approach, whether it behttps://doi.org/10.1016/j.jccase.2018.03.003
1878-5409/© 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

S. Miura et al. / Journal of Cardiology Cases 18 (2018) 13–16

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aortic valve repair or replacement, with these ﬁndings supportingthe concept that UAV and BAV are two discrete entities. Besides,
there is a growing interest in congenital aortic valve disorders, asindications for transcatheter aortic valve implantation have been
expanding to include patients with congenital aortic valve disease,particularly bicuspid aortic stenosis from those with calciﬁed anddegenerative AS [6]. Nevertheless, preoperative diagnosis of UAV israre and sometimes misleading. A systematic review reported that
only 23 cases of 231 UAV patients were identiﬁed preoperatively
using TTE while an additional 16 cases were diagnosed throughtransesophageal echocardiography (TEE).
In this report, we describe two cases that focus on the difﬁcultyin discriminating between UAV and BAV, both preoperatively andintraoperatively, with careful pathological examination of surgical
specimens helping to reach a ﬁnal diagnosis.
Case report #1
A 30-year-old woman was referred with worsening exertional
dyspnea. On physical examination, grade 4/6 systolic ejection
murmur was audible at the right sternal border. A TTE displayed anormal left ventricular (LV) size with preserved systolic function[LV ejection fraction (LVEF), 69%], complicated by a thickened
aortic valve with spotty calciﬁcation, which was assessed as asevere AS (aortic valve area calculated by Doppler method,0.67 cm2), along with a trivial AR. This examination, however,
did not provide a detailed observation on the leaﬂet morphology
due to inadequate image qualities. A subsequent TEE, however,revealed that the etiology of her valve abnormality could be BAV
based on clear three-dimensional live images of the two leaﬂets inboth lateral positions and two commissures between themFig. 1.

without any raphe structure with an eccentric oriﬁce (Fig. 1Aand B). A cardiac computed tomography (CT) revealed normal
coronary arteries without any dilatation of the ascending aorta(Fig. 1C) with two cusps of almost the same size lined up with twocommissures between them, which were indicative of a mildly
calciﬁed BAV. At operation, the valve was replaced with a 19-mm
prosthetic valve and was reported as a BAV based on the removed
valve specimen (Fig. 1D and E). A macroscopic pathologicalexamination, however, revealed that it was an acommissural
UAV. The surgical specimen exhibited an eccentric oriﬁce with noobvious commissures conﬁrmed at each edge. The area that wasthought to be a commissure on the TEE examination was almost
the same width as the other areas of the leaﬂets with the elasticﬁbers in the commissure-like area displayed continuously in “itscircumferential direction” (Fig. 1F). A similar observation wasobtained on the other edge, which supported the claim that thecongenital valve consists of one piece of leaﬂet, not two leaﬂets
with commissural structures.
Case report #2
A 50-year-old female with a history of hyperthyroidism wasreferred complaining of a gradual development of dyspnea. A TTE
showed a severe AS (peak transaortic velocity, 4.5 m/s) with mild
to moderate AR while the systolic function was preserved (LVEF,65%) with a normal LV size. A TEE was performed because close
observation on TTE was difﬁcult due to the extremely heavy
calciﬁcation of the valve. The TEE ﬁndings suggested that the valve
had a single unfused commissure, or unicommissural UAV,
attached to the aorta between the right coronary cusp (RCC)
and left coronary cusp (LCC) positions in the short-axis viewThree-dimensional live transesophageal echocardiography (short-axis view) during mid-systole (A) and mid-diastole (B), showing two commissures in theanterior (yellow head) and posterior positions (red head) in the absence of raphe, and the right-left located leaﬂets (dotted purple line) formed an eccentric oriﬁceopening. (C) Three-dimensional cardiac CT scan described two leaﬂets at almost same size were lined with two commissures, mimicking BAV with a trivial
calciﬁcation (yellow arrow). Surgical specimen of the removed aortic valve from aortic side (D) and from LV side (E). The shape of oriﬁce was eccentrically long andnarrow with no visible commissures conﬁrmed on each edge. The sharply curved area (red arrow) held a similar width to that of other sections of the leaﬂet, whichon LV side was accompanied by the formation of a nodular calciﬁcation. (F) Microscopic ﬁndings of the curved section on hematoxylin and eosin stain. Elasticﬁbers in the commissure-like area displayed continuous sequence in “its circumferential direction” (black arrowheads).
RCA, right coronary artery; LCA, left coronary artery; CT, computed tomography; BAV, bicuspid aortic valve; LV, left ventricle.

S. Miura et al. / Journal of Cardiology Cases 18 (2018) 13–16

without any obvious raphe structure with a valve oriﬁce that waseccentrically oval (Fig. 2A). CT ﬁndings demonstrated a moderatelydilated ascending aorta with a normal-sized aortic root but noadditional information regarding valve anatomy due to the heavy
valve calciﬁcation. The symptomatic patient underwent a surgicalaortic valve replacement with a 23-mm bioprosthetic valve, alongwith a replacement of the ascending aorta. Inspection of theremoved aortic valve was reported as a unicommissural aortic
valve with a slit between the RCC and the LCC zones (Fig. 2B and C).
The pathological diagnosis however, was BAV, which was different
from both the preoperative and intraoperative diagnosis. Detailed
histopathological examinations clariﬁed that elastic ﬁbers weretravelling in a radial direction, not in a circumferential one in theleaﬂet area between the non-coronary cusp (NCC) and LCC zones(Fig. 2D) which strongly suggested that the two leaﬂets were notoriginally attached. Elastic ﬁbers in the area between the NCC/RCC
zones were running in the circumferential direction, which can beinterpreted as a congenitally fused cusp (Fig. 2E).
Discussion
Two-dimensional TTE and TEE can play a central role inassessing congenital aortic valve disease. Two forms of UAV(acommissural and unicommissural) have been described on thebasis of the absence (or presence) of a lateral attachment of thecommissures to the aorta at the level of the oriﬁce [7]. Typically,
BAV shows only two leaﬂets and two complete commissures. A
previous study showed that out of 932 stenotic aortic valves
surgically excised in severe AS patients 54% of the total had
congenitally malformed valves with unicommissural UAV in 5%,
acommissural UAV in 0.4% and BAV in 49% [8]. However, valve
structure in all cases was determined by the macroscopic
observation of the excised valve and not based on pathohistologicalﬁndings which might, in the real world, lead to an underestimationof the incidence of congenital aortic valve disease. Additionally,Fig. 2.

15

there is a noteworthy discrepancy regarding the interpretation ofvalve structures between cardiac surgeons and cardiac pathologists when, as reported by Roberts et al. [9], patients withhemodynamically signiﬁcant aortic valve disease underwent
isolated aortic valve replacement. We believe that the mostreliable preoperative diagnosis for UAV and BAV should be basedon the number of commissures present and that distinguishing
between a commissure and a raphe using imaging modalities
depends on its attachment level in relation to the coronary ostia as
proposed by Anderson [10]. These characteristics might beexamined more closely using TEE or cardiac CT than TTE.
Nevertheless, we suggest that those distinctive ﬁndings areincreasingly difﬁcult to examine even using imaging modalities
for more advanced congenital aortic valve disease, such as the twocases presented, mainly due to heavy valve calciﬁcation or theacquired fusion of leaﬂets. In the ﬁrst case, the two separate leaﬂets
were clearly seen with two commissures on a three-dimensional
TEE image which led to a tentative diagnosis of BAV. The valve
oriﬁce was relatively linear in appearance, which is one of thecommon ﬁndings in BAV [8]. BAV was more suspect as the cause ofher stenotic valve because of the intraoperative ﬁndings revealing
an eccentrically long and narrow oriﬁce conﬁguration as opposed
to a pinhole one, which is typical to an acommissural UAV [10] andled to the misdiagnosis. Contrary to our expectations, thehistopathological examination concluded that the aortic valve
was an acommissural UAV. In the second case presented, we
suspected the aortic valve to be a unicommissural UAV based on
the preoperative TEE ﬁndings which clearly demonstrated an oval
oriﬁce relatively typical to a unicommissural UAV, with anattachment to the aorta in the commissure between the RCCand LCC. In addition, even intraoperative ﬁndings supported thepreoperative diagnosis suggesting a unicommissural UAV wasmore likely than an acommissural type because of the valve having
a single commissure structure. The intraoperative diagnosis,
however, did not match the conclusions from the pathologicalTransesophageal echocardiography during mid-systole in the short-axis view (A) exhibiting a commissure attached to aorta (yellow arrow) and an oval-shaped
aortic valve opening with heavy calciﬁcation. Surgical specimen of the removed aortic valve from aortic side (B) and from LV side (C). Two leaﬂets consisting of thefused NCC/RCC and LCC showed a commissure between them while the zone between NCC and LCC (red arrow) displayed a tight fusion complicated by a nodularcalciﬁcation. There was a concavity in the fused area between NCC and RCC (black arrow) but no apparent raphe structure. Histopathological cross sections of thezone between NCC and LCC and the fused area between NCC and RCC were indicated by a yellow-colored square (D) and (E) in (B), respectively. Elastic ﬁbers
around the zone were travelling to the short axis, not to the circumferential [black arrowheads, in (D)], suggesting that the zone contained commissural structure
while the elastic ﬁbers in the fused NCC/RCC area showed the circumferential layout [black arrowheads, in (E)].
LV, left ventricle; NCC, non-coronary cusp; LCC, left coronary cusp; RCC, right coronary cusp.

16S. Miura et al. / Journal of Cardiology Cases 18 (2018) 13–16

diagnosis. Both of these cases proved difﬁcult in identifying
congenital aortic valve disease both preoperatively and intraoperatively. Diagnostic information was provided in both cases by
the arrangements of running elastic ﬁbers around zones of interest.
In Case #1, the commissure structure was not conﬁrmed as ﬁbrous
tissues at the commissure-like areas even though they were
histologically connected at the two leaﬂets, suggesting anacommissural UAV. In Case #2, the leaﬂet area [(D) in Fig. 2]
between the NCC/RCC and LCC that allowed the valve to mimic a
unicommissural UAV turned out to be physically fused with heavy
calciﬁcation and histologically disconnected, indicating BAV.
Several clinical presentations can help in discerning thedifferences between these similar entities. For example, it isreported that the UAV is mainly found in males vs. females at aratio of 4:1 [7] and, in general, patients with UAV tend to present
with cardiac symptoms much earlier in life than those with BAV(between 30–50 years of age for UAV vs. 60–80 years old for BAV)
as witnessed in our ﬁrst case [8]; compared to patients with atricuspid AS, valve dysfunction and progression develop at a fasterrate plus, unlike in our ﬁrst case, patients with acommissural UAV
are predominantly found in their infancy [1].
The ultimate goal of this case report was to improve thepreoperative diagnosis of congenital aortic valve diseases using
multiple imaging modalities and clinical presentations. Thereremain a remarkable number of misleading cases, as demonstrated
in our report. Hence, it is strongly recommended that an accurate
diagnosis should be attempted at the earliest stages of congenitalaortic valve disease. Additionally, it remains imperative that
careful follow-up including conﬁrmation via pathological diagnosis be pursued for patients undergoing surgery, if they are ﬁrst
found to be at an advanced stage or remain undiagnosed
preoperatively.

Financial support
None.
Conﬂict of interest
None declared.
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