Surgical Technique
Pre-operative evaluation for suspected coronary artery disease (CAD)
with invasive coronary angiography should be performed when surgery or
an intervention is planned to determine if concomitant coronary
revascularization is indicated [1]. Coronary angiography is
recommended before valve surgery in men >40 years and
post-menopausal women, in patients with history of cardiovascular
disease, symptoms of angina, objective evidence or suspected myocardial
ischemia, decreased left ventricular systolic function and in case of
cardiovascular/coronary risk factors [1]. Alternatively, coronary
computed tomography (CT) can be used to rule out CAD in patients at low
risk [2]. These imaging techniques can provide more information than
the simple presence of CAD, such as coronary anatomy, origin, course and
spatial relationships [1,2]. Nevertheless, coronary angiography
and/or CT-scan are not always performed before aortic valve (AV) surgery
(young patients without risk factors or urgent cases like endocarditis)
or can be undervalued when stenotic lesions are excluded. Coronary
anomalies such as anomalous left circumflex coronary artery
(LCA) arising from the right sinus of Valsalva, strictly leaning on the
aortic annulus, can have serious consequences in aortic valve/root
surgery, particularly if unrecognized or underestimated [3,4]. In
this paper, we present three patients with an anomalous course of the
LCA undergoing AV replacement (AVR) with three different prostheses,
without prosthetic downsizing.
Coronary angiography was performed in two patients. All patients
underwent a preoperative CT-scan (Fig.1A). Chest was opened by median
sternotomy and mild hypothermic cardiopulmonary bypass (32–34°C) was
initiated with ascending-aortic and right-atrial cannulation. After
cross-clamping and infusion of antegrade crystalloid cardioplegia,
aortotomy was performed with a transverse incision just above the
sinotubular-junction avoiding the oblique incision towards the
non-coronary sinus. Aortic valve was explored, leaving the native cusps
in situ in presence of severe leaflet/annular calcifications to avoid
any damage to the LCA during excision. A 1.0/1.5-mm coronary probe was
placed into the assumed anomalous LCA to verify the anomalous course
between the aortic root/annulus and the left atrial roof. A careful and
complete dissection of the LCA was performed to free the artery from the
aortic wall along its course, initially on the anterior and right side
of the root, then posterior to the aorta at the level of the annulus
until the atrio-ventricular groove (Fig.1B). Once the LCA was completely
free from the surrounding tissues, we proceeded with native cusps
excision. A meticulous attention was paid to the mobilized anomalous LCA
when placing annular sutures (Fig.1C) using standard 2-0 U-stiches with
small/soft pledgets on the ventricular side. Three different prostheses
were used: a mechanical valve (On-X 23mm) in a 31 years-old male with
bicuspid aortic valve and severe regurgitation due to active
endocarditis (E. Faecalis), a stented bioprosthesis (Carpentier Edwards
magna Ease 23mm) and a rapid deployment sutureless valve (Perceval-S
Size-M) in two ladies of 67 and 79 years with severe aortic stenosis,
respectively. A complete LCA scheletonization allowed us to avoid
prosthetic downsize, implanting valves of sizes exactly corresponding to
every single annulus. Once the prosthesis was deployed, we verified the
absence of compression on the LCA by the sewing-ring for stented
prostheses (Fig.1D) or by the inflow-ring/sinusoidal struts for the
sutureless valve. Aortotomy was closed in the standard fashion, avoiding
the use of pledgets on the right side. After deairing and clamp removal,
careful attention must be paid to LCA verifying its mobility with a
blood-full root and the absence of hematoma, minor bleeding or
compression by the surrounding structures. No sealants/hemostatic
products were used. The patients were weaned from cardiopulmonary bypass
in sinus rhythm without ischemic signs. Postoperative course was good in
all cases without signs/symptoms of perioperative ischemia.
Postoperative CT-scan confirmed the absence of LCA compression (Fig.2)
in all patients, currently in good clinical conditions at last FU.
Anomalous origin of the coronary arteries is usually an incidental
finding in patients undergoing cardiac catheterization. Coronary
anomalies were found in 99 patients among 3,233 coronary angiograms by
Sidhu and coll. [5], with an incidence of 3.06%. Patients’ mean age
was 56.2years (range: 20-86). Ectopic origin of LCA from the right sinus
or right coronary artery was noted in 13 patients (0.40%), usually with
a benign clinical course [5]. Appropriate imaging is crucial to
understand the spatial relationship between the anomalous coronary
arteries and the aortic valve/root before surgery but in the real life
is not always performed, particularly in younger patients or in absence
of coronary risk factors. In addition, the low incidence of this anomaly
in clinical practice could reduce the proper attention of surgeons,
particularly when critical stenoses are not reported. Anomalous LCA with
a retro-aortic trajectory has major implications during AV surgery,
particularly when unrecognized or underestimated [3-5]. Injury to
the LCA may occur in isolated AVR by compression from the prosthesis
(sewing ring) or ligation by annular sutures while resection of the
non-coronary sinus or suturing could complicate aortic root/sinus
repair. A careful surgical planning and management is mandatory and
every step requires a strong attention as well as the choice of the
right prosthesis. Implanting a smaller-sized prosthesis with the aim to
avoid coronary artery distortion or compression has been reported
[3,6], although patient-prosthesis-mismatch can occur with serious
complications in small aortic annuli. In this small series, we have
avoided this problem through the complete LCA skeletonization. When
preoperative echocardiography shows a small aortic annulus and a
standard stented prosthesis is not suitable, we suggest to use a
sutureless aortic valve as reported by Cerillo and coll. [7]. In
alternative, transcatheter aortic valve implantation has been described
with success, using when necessary, a coronary guidewire before
deploying TAVI to prevent coronary occlusion/stenosis [8]. Whenever
postoperative ischemia should be detected after AVR with anomalous LCA,
compression or surgical ligation must be immediately suspected and ruled
out. If there is high suspicion of compression as the mechanism of
ischemia, percutaneous coronary intervention can be a reasonable
treatment option [6]. Coronary anatomy should always be evaluated in
elective or urgent AVR. Careful and complete arterial skeletonization is
recommended in presence of anomalous LCA to avoid prosthetic downsize
and patient-prosthetic mismatch with every type of prosthesis.