Material and Methods
For this retrospective analysis, we included data for all patients with
BAV who underwent aortic root replacement using Tirone’s procedure from
December 2007 through January 2022. Patients with acute aortic
dissection or age <18 years were excluded. The study was
approved by local Ethics Committee (IRB00013412, “CHU de Clermont
Ferrand IRB #1”, IRB number 2022-CF015) with compliance to the French
policy of individual data protection.
In brief, after the chest was opened with a median sternotomy, and
application of systemic heparinization, the patient was started on
extracorporeal circulation with direct cannulation of the arch or
ascending aorta and right atrial cannulation. Cardiac arrest was
achieved by means of infusion of cold blood cardioplegia, first
anterograde into the coronary ostia and then retrograde in the majority
of cases. Transsection to open the ascending aorta was done above the
commissures plane. The aortic root and the valve were carefully
inspected by the operating surgeon. The BAV was classified according to
Sievers, followed by cutting of the coronary ostia, dissection from the
aortic root to the aortic annulus plane, and resection of the sinuses.
After suspension of the commissures, we used a Hegar dilator to measure
the aortic annulus. The aortic valve was carefully assessed for
configuration and coaptation. When cups presented calcification,
decalcification was performed first. In all instances, a Dacron graft
was used, initially with a graft 4 mm larger than the measured diameter
of the aortic annulus. Then after a few years, a Dacron graft 2 mm
larger was usually chosen, although sometimes a graft was used that was
the same diameter of the aortic annulus. We routinely use Vascutek
Gelweave® (Vascutek Terumo, Glasgow, Scotland). Initially, we performed
a proximal subannular fixation of the vascular prosthesis by U-shaped
stitches associated with a running suture, but we changed to a technique
using a single inflow suture line.
After aortic valve reimplantation and co-aptation assessment, we used a
Schäfers caliper to measure the plicature started by the unfused leaflet
at 10/12 mm. Measurement of the other leaflet was impossible because of
the symphysis and hypoplastic commissure. We then operated on the second
leaflet (symphysis leaflet) to obtain an equal length of the free edges.
Additional repair was performed as needed, consisting of fenestration
and/or patch repair. According to the operating surgeon’s preference,
the central plication sutures were performed with 6-0 polypropylene
stitches. Reimplantation of the coronary ostia was performed using the
button technique.
For follow-up, all patients underwent preoperative transthoracic
echocardiography (TTE), intraoperative transesophageal echocardiography,
and postoperative TTE before hospital discharge, yearly thereafter for 5
years, and then less frequently. Points of interest included the
diameter of the aortic annulus, the mode of aortic valve insufficiency
and potential prolapse and sclerosis, the mean systolic gradients, and
the left ventricular ejection fraction. Events were defined as such by
timing of their initial diagnosis.
Statistical analysis was performed using Stata software (version 15;
StataCorp, College Station, Texas, USA). All tests were two-sided, with
a Type I error set at 0.05. Categorical variables are expressed as
number of patients and associated percentages, and continuous variables
as mean±standard deviation or median [25th;
75th percentiles], according to statistical
distribution. Censored data (overall survival) were estimated using the
Kaplan-Meier method. The 5- and 10-year survival rates are presented
with their 95% confidence intervals (CIs).