Materials and Methods
Study design
In this retrospective longitudinal cohort study, data of all adult
patients with aortic valve disease who underwent AVR with a Perceval® prosthetic valve between February 2015 and October
2020 in Hospital de Santa Maria (Lisbon, Portugal) was retrospectively
collected from an available hospital database. Approval of the study and
access to the data was granted by the ethical committee of the hospital
involved (Comissão Ética Centro Hospitalar Lisboa Norte, identification
number: 510/18).
Patients
Data collected included demographics and preoperative characteristics,
such as comorbidities, EuroSCORE II, presence of atrial fibrillation or
pacemaker, left ventricular (LV) function and history of previous
cardiac surgery. We also collected intraoperative data, such as the
aortic cross-clamping and CPB times, size of the valves implanted and
transvalvular gradients, as well as in-hospital stay and postoperative
complications.
Endpoints were the clinical and hemodynamic performance, safety and
durability of the Perceval valve in AVR, evaluated through the following
criteria: mortality and overall long-term survival, structural valve
deterioration, operatory times (aortic clamping and CPB times), mean ICU
and total hospital stay, postoperative complications - including PPI and
infection rates (respiratory, urinary and/or bacteremia of unknown
origin), endocarditis, stroke, early mortality (defined as in-hospital
or up to 30 days after surgery), abnormal bleeding (defined as
> 2ml/kg/h in first 2-3 hours, > 1ml/kg/h in
the next 3 hours and/or > 0.5ml/kg/h in 12 hours),
new-onset atrial fibrillation (paroxysmal, persistent or permanent),
significant renal dysfunction (14) and need for intra-aortic balloon
pump, surgical exploration for bleeding, renal replacement support
(performed through continuous veno-venous hemodiafiltration) or
aminergic support >24h (performed with at least one of the
following: epinephrine, norepinephrine, dobutamine) - and postoperative
echocardiographic findings.
The Perceval®valve
The Perceval ® prosthetic valve (Sorin Group,
Saluggia, Italy) consists in 3 bovine pericardial cusps mounted on a
self-expanding nitinol stent comprising two rings, allowing for
stabilization simultaneously at the aortic annulus and at the
sinotubular junction (STJ), and nine vertical struts covered by a thin
coating of Carbofilm™, to improve biocompatibility. The stent holds the
valve in place without any permanent suture, by exerting radial force on
the patient’s aortic annulus and aortic root. It is also flexible,
allowing it to adapt to the anatomy of the aorta and its movements, thus
relieving the stress on the leaflets. The valve is folded up by
collapsing the inflow and outflow rings with an atraumatic compression
device, allowing the pericardial leaflets not to be crimped and remain
mobile, ensuring they are not damaged (15) - in contrast to the
necessary crimping of the TAVI, in which the leaflet’s collagen fibers
are damaged (10). The Perceval ® valve is currently
available in four sizes: S, to be implanted in annular sizes from 19 to
21 mm, M from 22 to 23 mm, L from 24 to 25 mm and XL for patients with
annular sizes of 27 mm (6).
Although the concept of sutureless bioprosthesis exists for over 40
years (16), the first reports evaluating implantation feasibility and
valve safety in humans were only released in 2007. It was CE approved in
2011 and FDA approved in 2016 (17).
Surgical technique
Indications for AVR were in agreement with the ESC/EACTS Guidelines for
the management of valvular heart disease at the time of the
interventions (18). The surgical approach was either standard median
sternotomy or upper J ministernotomy. All patients were operated on or
supervised by an experienced surgeon in this procedure. Anaesthetic and
surgical techniques were standardized. A high transverse aortotomy close
to the epiaortic fat pad was performed, leaving a free edge for closure
after implantation of the device. The native calcified aortic valve was
excised, and the aortic annulus completely decalcified. Sizing of the
annulus was done using dedicated sizers.
Concomitant procedures were performed in line with current department
practices and always with the goal of minimizing aortic cross-clamping
and CPB times. For instance, aortic graft anastomosis, when needed, was
performed prior to cannulation using tangential aortic cross-clamping.
After aortotomy closure in the usual fashion, thorough de-airing with
CO2, release of the aortic cross-clamp and weaning from CPB were
performed. Valve function was evaluated by intraoperative
transesophageal echocardiography in all patients. Following the
procedure, patients were transferred to the ICU and managed accordingly.
Antiplatelet therapy was instituted. (19).
Statistical analysis
Statistical analysis was performed using IBM SPSS Statistics v27.1 (New
York, United States of America). Categorical variables are reported as
absolute and relative frequencies. For continuous data, means, median
and standard deviations were calculated. Cumulative survival and freedom
from events were estimated using the Kaplan–Meier method, with 95%
confidence intervals.