SUTURELESS AORTIC VALVE REPLACEMENT: DOES IT MAKE SENSE?
Kenan Sever1 Ass. Prof. Dr., Oguz
Konukoglu1Ass. Prof. Dr., Ozgur
Yildirim1 Ass.Prof Dr.., Hakan
Kilercik2 Ass. Prof. Dr, Denyan
Mansuroglu1 Prof. Dr.
1-Istanbul Yeni Yuzyil University Gaziosmanpasa Hospital, Cardiovascular
Surgery Department
2-Istanbul Yeni Yuzyil University Gaziosmanpasa Hospital, Anesthesiology
Department
Corresponding Author: Oguz Konukoglu
Adress: Yeni Yüzyıl Üniversitesi, Özel Gaziosmanpaşa Hastanesi, Merkez,
Çukurçeşme Cd. No:51, 34245 Gaziosmanpaşa/İstanbul, TURKEY
e-mail:oguzkonukoglu@yahoo.com
Telephone: 0090 505 8689732
Fax: 0090 212 615 38 49
ABSTRACT
BACKGROUND
Aortic valve stenosis is the most common valve disease in the elderly.
Sutureless aortic valve replacement (AVR) has been introduced as an
alternative to conventional AVR in elderly high-risk patients. This
study aims to report our single-center experience regarding early
outcomes.
METHODS
Between December 2014 and December 2019, 91 patients (45 women, 46 men)
underwent aortic valve replacement at our clinic (49 sutureless, 42
conventional). The inclusion criteria were severe symptomatic valve
disease, New York Heart Association (NYHA) class II or higher, and age
>55 years. Perioperative clinical and echocardiographic
outcomes were assessed in all patients.
RESULTS
The average age was 73.08±7.53 years in the sutureless group and
66.26±8.63 years in the conventional group. The mean cross-clamp and
cardiopulmonary bypass (CPB) times were 72.86 and 91.88 min,
respectively, in the sutureless group, and 104.96 and 119.81 min,
respectively, in the conventional group. In the sutureless group, 30
(61.2%) patients underwent additional procedures such as CABG, mitral
interventions, tricuspid repair, ascending aortic surgery, and myxoma
removal. Preoperative peak and mean pressure gradients decreased from
78.16 and 48.95 mmHg to 17.47 and 10.06 mmHg postoperatively in the
sutureless group, and from 71.53 and 43.89 mmHg to 29.16 and 15.14 mmHg
in the conventional group. Paravalvular leak and permanent pacemaker
requirement due to AV-block rates were 6.1%. The mean ICU stay was 3.69
and 2.31 days, the mean hospital stay was 10.08 and 8.62 days, and the
30-day overall mortality rates were 8.2% and 4.8% in the sutureless
and conventional groups, respectively.
CONCLUSION
The evaluation of our experience suggests that sutureless aortic valve
replacement has advantages in terms of shorter cross-clamp time, reduced
CPB duration, and postoperative aortic gradients. Its benefits could be
more prominent in complex cases or minimally invasive surgery.
Keywords: sutureles, aortic valve, intuity, perceval
There is no conflict of interest about the authors of this study.
.
Aortic valve stenosis is the most common valve disease in an aging
population, and the annual mortality expectancy in patients with severe
stenosis is 30-50%.1,2 The most effective treatment
for severe aortic valve stenosis is aortic valve replacement (AVR).
Clinical studies show improved left ventricular systolic and diastolic
function due to the regression of left ventricular hypertrophy after
aortic valve replacement.3 Biologic aortic valves are
preferred to reduce postoperative gradient levels and avoid
complications related to warfarin use in elderly patients with aortic
stenosis. Clinical reports indicate a low gradient and long-term
durability with pericardial and porcine valves, with good results up to
20 years.4 However, these valves are implanted on a
stent with a Dacron graft, and a residual gradient (depending on graft
bending) may occur in a narrow and calcified annulus. Bioprosthetic
valves without stents have been developed to overcome these problems and
provide a greater orifice area.5 The advantage of the
stent-free structure is that it increases the effective valve area and
decreases the gradient. However, their implantation is more difficult
compared to the stented valves and leads to increased surgical
cross-clamp time.6 Transcatheter-mediated aortic valve
implantation (TAVI) is recommended in the elderly and high-risk
patients; however, studies have shown that TAVI has high rates of
complications.7 Sutureless aortic prosthetic valves
developed in recent years maximize effective valve orifice area and
reduce cross-clamp time.8,9 In the sutureless
implantation technique, in addition to conventional AVR procedures, the
valve is placed in a sutureless fashion or positioned with three
stitches, resulting in a significant reduction in cross-clamp
time.10 These valve prostheses have been used in our
country since 2012. This study aims to discuss the short-term results of
49 sutureless AVR cases and compare them with conventional AVR.
MATERIALS AND METHODS
Between December 2014 and December 2019, 49 patients (30 women, 19 men)
received sutureless aortic valves, and 42 patients underwent
conventional aortic valve replacement at our clinic by the same surgeon.
The inclusion criteria were severe symptomatic valve disease, New York
Heart Association (NYHA) class II or higher, and age >55
years. All patients received informed consent forms. The necessary
permissions were obtained for the study from the ethics committee of our
university.
Two types of sutureless valves can be used with the diagnosis of severe
aortic valve disease in our country: Perceval S (Sorin Biomedica Cardio
Srl, Sallugia, Italy) valves, and Edwards Intuity (Edwards Lifesciences,
Irvine, CA, USA) valves. We used 16 Sorin Perceval valves (32.7%) and
33 Edwards Intuity valves (67.3%) for our patient groups.
A median sternotomy was performed on most patients following general
anesthesia and orotracheal intubation. Unicaval venous and aortic
arterial cannulation was applied to isolated cases. Bicaval venous
cannulation was used in complicated cases such as concomitant tricuspid
or mitral interventions. The aorta was split from the pulmonary artery.
Transverse/oblique aortotomy was performed after placing the
cross-clamp. The heart was arrested by applying antegrade isothermic
blood cardioplegia from the coronary ostia. The process was repeated at
intervals of 20 minutes until the aortotomy was closed. In complex
cases, cardiac protection was achieved by retrograde cardioplegia. The
aortic valve was excised, and the annulus decalcified. The valve size
was measured using original valve scales.
For Sorin Perceval valve implantation, a transverse aortotomy was
performed about 2 cm above the sino-tubular junction. After excision and
decalcification, the valve applicator was advanced to the aortic
position. The valve was expanded after verifying the appropriate
positioning of the prosthesis. The applicator was taken out. A post
dilatation balloon was inserted in the aortic valve and dilated for 30
seconds at a pressure of 4 atmospheres.
For Edwards Intuity valve implantation, an oblique aortotomy was
performed about 1 cm above the sinotubular junction. Following excision
and decalcification, three 4-0 prolene sutures were placed at the nadir
of the aortic sinus. The valve was prepared by washing in saline
solution for 2 minutes. The balloon inflator was filled with a 40 ml
saline solution, and a balloon connection was made. The sutures
(previously passed through the commissures) were unified by snares and
passed through the sewing ring of the lid. The guide sutures were
tightened to advance until the valve was placed in the exact aortic
position with the help of the valve applicator. The snares were
squeezed, and the valve was fixed to its position. The balloon inflation
was achieved at pressures ranging from 3 to 5 atmospheres for at least
10 seconds, and the stabilizer ring under the valve was expanded. The
guide sutures were firmly tied above the valve annular ring, and the
valve applicator was taken out.
Following valve implantation, the aortotomy was closed with 4-0 or 5-0
prolene continuous sutures. After the cross-clamp was removed, the
cardiopulmonary bypass was terminated following standard procedures, and
epicardial pacemaker wires were routinely placed.
In the presence of coronary bypass graft surgery (CABG), distal bypasses
were done before valve implantation and proximal bypasses after aortic
valve implantation under cross-clamping.
In the presence of additional mitral and tricuspid valve intervention,
atriotomy and valve procedures were performed before aortic valve
implantation.
Valve position and possible leakage after implantation were evaluated
with intraoperative TEE in all patients. All patients underwent
transthoracic echocardiography before hospital discharge.
Demographic data, preoperative, and postoperative parameters were
compiled by retrospectively accessing the data of all patients
undergoing aortic valve implantation.
SPSS Ver. 22.0 (SPSS Inc., Chicago, IL, USA) was used in data analysis.
Average and standard deviation for numerical evaluations and percentage
values for categorical variables were calculated. For categorical
variables, the results were compared with the chi-square test. The
numerical groups were compared with paired-samples t-testing. For
non-parametric groups, groups were compared with independent samples
test (Mann-Whitney U). All p-values <0.05 were considered to indicate
statistical significance.
RESULTS
Between December 2014 and December 2019, 49 patients (30 [61.2%]
females, 19 [38.8%] males) underwent sutureless AVR valve
implantation at our clinic. The average age was 73.08±7.53 years. Table
1 shows the demographic information.
In addition to sutureless AVR, 30 (61.2%) patients underwent additional
procedures such as CABG, mitral interventions, tricuspid repair,
ascending aortic surgery, and myxoma removal. (Table 2) Sorin Perceval S
was used in 16 patients (32.7%) and Edwards Intuity in 33 (67.3%)
patients. The average cardiopulmonary bypass time was 104.96±41.63 min.
(76.47±24.79 min. in isolated cases), and the average cross-clamp time
was 72.86±34.09 min. (51.05±21.68 min. in isolated cases)(Table 3). The
average erythrocyte suspension requirement was 3.90±2.85 units in the
sutureless group (3.42±1.77 units in isolated cases). The
hospitalization time in the intensive care unit was 3.73±6.20 days, and
the discharge time was 10.08±6.56 days. (Table 5) Three patients
underwent revision for bleeding.
Preoperative and postoperative echocardiographic data are shown in Table
4. The preoperative and postoperative ejection fractions were
54.77±10.90 and 55.87±9.87, respectively (p=0.313). The preoperative and
postoperative maximum aortic gradients were 78.16±30.24 and 17.47±6.16,
respectively (p=0.000); the preoperative and postoperative mean aortic
gradients were 48.95±21.28 and 10.06±3.63, respectively (p=0.000).
In one case, the patient received a Bentall operation due to aortic root
rupture. In this case, death occurred in the ICU period.
Aortic valve insufficiency >2° was seen in 4 patients. One
patient died in the ICU. Two patients underwent reoperation for heart
failure symptoms, and one of them died after the second operation.
Aortic valve insufficiency >2° was zero in the conventional
control group.
Postoperative AV block that required permanent pacemaker occurred in 3
(6.1%) patients.
Cumulative short-term mortality was 8.2% (4 patients) in the sutureless
group and 4.8% (2 patients) in the conventional control group, p=0.683.
DISCUSSION
Aortic stenosis is most common in western countries with an aging
population.1 The increase in high-risk patients has
led to the development of less invasive treatment options and an
increasing number of cases.11 Currently, TAVI and
sutureless aortic valve replacement are highlighted as less invasive
methods.2
Sutureless valves showed better hemodynamic results in our series in
terms of gradient change (preoperative gradient-postoperative gradient)
after implantation. After the operation, the maximum gradient change was
60.68 mmHg in the sutureless group and 49.74 mmHg in the conventional
group (p=0.003). The mean gradient change was 38.88 mmHg in the
sutureless group and 28.74 mmHg in the conventional group (p=0.004).
(Table 5) Studies have shown that sutureless aortic valves reveal a
stable reduction of gradients postoperatively. 3,11,12D’Onofrio et al. observed that transapical and sutureless valves have
lower mean aortic gradients than conventional aortic valve
replacements.11
The sutureless implantation technique is associated with a reduction in
cross-clamp and total perfusion times, which are independent risk
factors.13 A study by Flameng et al. found that the
average cross-clamp and total perfusion times were 22 and 46 minutes,
respectively, in selected cases.14 In a meta-analysis
compiled by twelve studies, isolated AVR times were 33 and 57 minutes,
and the average cross-clamp and total perfusion times for conventional
isolated AVR cases in the STS knowledge base were 78 and 106 minutes,
respectively.2 Cross-clamp and total perfusion times
for isolated AVR in our patient group were 51 and 76 minutes,
respectively.
In our patient group, 30 patients (61.2%) underwent additional
procedures such as CABG (51%), ascending aortic procedure (8.2%), MVR
(6.1%), and other operations. Cross-clamp and total perfusion times
were 72 and 104 minutes, respectively, in patients undergoing additional
procedures in the sutureless group.
Paravalvular aortic regurgitation is seen more commonly in sutureless
than in conventional aortic valve
replacements.2–4,15,16 Our study group showed
moderate/severe regurgitation in 3 (6.1%) patients and no regurgitation
in conventional cases (p=0.121). The AV block is a known
complication.2,10,12,15,16 Three patients developed
permanent AV conduction blocks requiring pacemaker implantation. We did
not see permanent AV blocks in the conventional group.
Mini sternotomy provides procedural and exposure advantages in isolated
AVR cases. Although we performed sternotomy in most of our patients, we
preferred the upper mini sternotomy in our last cases for isolated
sutureless AVR.
Although we started our learning curve with Edwards Intuity, currently,
we prefer to use the Sorin Perceval S valve for its design. The first
handicap of the Intuity valve is the wide and rigid collar under the
valve. This extra-anatomic position can cause stretching of the mitral
valve. One of our patients experienced aortic root rupture following
blunt trauma due to the inflation of the collar. The patient received a
Bentall operation and died eventually. The second handicap can be seen
in late re-operations with the Intuity valve. It can be highly
challenging to detach the valve in cases of infra-aortic and possible
mitral adhesion of the collar.
Factors that achieve success in sutureless valve implantation based on
our experience are as follows: 1) Not to make too much valve resection;
2) Appropriate sizing; 3) Avoiding barotrauma while inflating the
balloon.
Mean ICU stay times were longer in the sutureless group (3.69 days in
sutureless, 2.31 in conventional, p=0.969) and mean hospital stay was
also higher (10.02 days in sutureless, 8.68 in conventional, 0.855).
Although there was no statistically significant difference between ICU
and hospital stay times, more than one day of mean stay in the ICU could
influence the costs. Also, the price of the sutureless valves is around
three-fold that of the bioprosthetic valves in our country.
We did not observe mortality in the isolated sutureless AVR group (19
patients). In a different series, isolated AVR groups had short-term
mortality that could be considered satisfactory, around 3%. We observed
a mortality rate of 13.3% (4 patients) among 30 non-isolated cases. Of
these, two patients received re-operations. In a multi-centric study
conducted in Europe, the mortality rate was reported as 12.9% on an
average in non-isolated sutureless AVR cases.17
A mortality rate of 8.2% (4 patients) was observed in the sutureless
group of our study. The mortality rate in the conventional group was
4.8% (2 patients). However, no significant difference was detected
between the sutureless and conventional groups (p=0.683). EuroSCORE 2
values of the sutureless group were significantly higher (5.51±7.29 for
sutureless, 2.80±3.52 for the conventional group, p=0.01). It showed
that a sutureless strategy was preferred in complicated cases to reduce
cross-clamp times. In previous studies on conventional aortic
replacement, the mortality rate was 4-10%, and factors such as advanced
age, low ejection fraction, renal insufficiency, and severe aortic
calcification were cited among the causes that influenced
mortality.18
Thus, sutureless valves offer better hemodynamic and intraoperative
results such as lower postoperative aortic gradient and shorter
cross-clamp and cardiopulmonary bypass times. However, sutureless valve
selection did not make a significant change in terms of hospital stay,
ICU stay, and mortality. These variables were also higher in the
sutureless group. Although it is not easy to clearly state whether or
not these handicaps are directly related to the sutureless technique, we
could not find convincing results that reveal superiority to
conventional aortic replacement.
Sutureless valve technology has brought new dimensions to aortic valve
replacement. It has unique advantages and unique complications. The
benefits could be enhanced in presence of additional procedures or
minimally invasive strategies with acceptable results.
LIMITATIONS OF THE STUDY
One limitation of this study was that it was based on data from a single
center with a limited number of patients. The study revealed early
outcomes, and it is necessary to have more data documenting long-term
results. Although age and patient characteristics were alike, the
EuroSCORE 2 values for the sutureless group were higher than those for
the control group.
CONFLICTS OF INTEREST
There is no conflict of interest relevant to this article.