Abstract
Background: Significant TR is common in patients with cardiac
disease and because of its prognostic importance, TV came to the
spotlight in the last decades. Functional TR is mostly treated when
undergoing left-sided valve surgery, whereas idiopathic TR surgery is
uncommon. The aim of this study is to compare the durability of
tricuspid valve annuloplasty techniques, and to explore the optimal
method for TV repair surgery.
Methods: 1005 patients who underwent tricuspid valve repair
from February 2012 to March 2019, were retrospectively studied. The
patients had tricuspid valve repair while receiving surgery for other
cardiac conditions. The study population was divided into Suture group
(n=483, 48.1%), and Ring group (n=522, 51.9%). Data variation between
and within the groups was analyzed with Mann-Whitney U test, Wilcoxon
rank-sum test, and Radit analysis.
Results: At two-year follow-up, in the Suture group, none/trace
TR subjects were 63.9%, and 1.4% had severe TR; In the Ring group
were: 63.9% none/trace, and 0.6% severe. Both groups’ two-year
follow-up TR status was significantly different with preoperative TR
status (p<0.05 ).
At two-year follow-up, Suture group had 63.9% none/trace and 1.4%
severe; and Ring group had 63.9% none/trace and 0.6% severe TR and
there was no significant difference between the groups
(p>0.05 ).
Conclusions: Both annuloplasty techniques have good short-term
outcomes. However, suture annuloplasty deteriorates faster than ring
annuloplasty, making the latter to be the ideal technique for TV repair.
Keywords: Tricuspid regurgitation, Ring annuloplasty, Suture
annuloplasty.
Background
Tricuspid Regurgitation (TR) is a disease of the right atrioventricular
valve. Trace or mild TR is a common finding even in healthy people; with
an occurrence rate of about 1% in the general
population.1 In a structurally normal tricuspid valve
(TV) apparatus, mild TR can be considered a normal
variant.2
For decades, TR has been considered a benign disease with a long
asymptomatic period. As a consequence, it has been relatively neglected
and did not receive enough attention. Data showed that significant
(moderate or greater) TR is common, with a 0.5% incidence on the
general population, with an increasing prevalence after the age of 75
years, particularly in women and in the presence of atrial fibrillation
(AFib),3 and is associated with a poor prognosis.
Because of its prognostic value in conditions such as ischemic heart
disease, mitral valve regurgitation, AFib, and heart failure, TV has
risen from the ”forgotten valve” to the spotlight in the last decades.
TR can be classified into different morphologic categories:Primary (or organic) TR is caused by congenital or acquired
defects of the TV apparatus; Secondary (or functional) TR is
caused by deformation of the TV apparatus secondary to dilation of the
TV annulus, leaflet tethering, and right ventricular (RV) remodeling as
a result of left-sided heart disease and pulmonary hypertension (PH);Isolated (or Idiopathic) TR, is another class of TR and it is
related to intra-cardiac device leads, AFib and right atrial (RA)
remodeling. In 80% of adults with significant TR, the incompetence is
caused by acquired right ventricular and annular dilation rather than
inherent valve pathology.4
Functional TR is mostly treated when undergoing left-sided valve
surgery, whereas isolated TV surgery is rarely performed, but is
recommended in patients with severe TR that are either symptomatic or
have progressive RV remodeling.
Generally, in patients with primary TR, repair mainly depends on the
degree of valve damage. Replacement may show better results over repair
in TR cases with severe valve lesions. For functional TR, there is
currently a clear tendency towards valve repair.
Tricuspid annuloplasty has been the most common technique used for
surgical correction of TR. TV annuloplasty typically consists of annular
size reduction with ring or suture techniques to bring closer the
leaflets and restore coaptation. First suture repair techniques were
described more than 50 years ago by Jerome Kay and Norberto De Vega.
Both techniques are currently been used in clinical practice, despite
recent studies suggesting better long-term results of ring annuloplasty
over suture annuloplasty.5 6 7 There is still a hot
debate on the indication, feasibility, long-term outcome, and
cost-benefit balance between the TV repair procedures among cardiac
surgeons. The great advantage of suture annuloplasty is that it is
technically more simpler, less time consuming and less costly; however,
suture techniques carry a higher risk of recurrent TR, according to
studies.8 Monika et al,9 did not
detect tissue tearing by the purse-string suture in the De Vega
annuloplasty, and considered suture annuloplasty a valid treatment
option for TR. Ring annuloplasty gained a lot of support from
studies,2 however, there are reports of increased
annular dehiscence with ring repair technique.6
Methods and Materials
A retrospective study of 1005 patients who underwent TV repair surgery
at the First Affiliated Hospital of Zhengzhou University, from July 2012
to August 2019.
All the patients had TV repair when undergoing surgery for other cardiac
conditions. Among the subjects, 662 (66%) patients had concomitant
left-sided valve surgery (AVR, AVP, MVR, MVP); 274 (27.2%) patients had
combined TV repair and various congenital heart defects repair, such as
ASD, VSD, TOF, PS and ECD; 48 (4.8%) patients simultaneously underwent
aortic artery interventions (Bentall procedure) and coronary artery
bypass graft surgery; and the remaining 21(2%) patients had other less
common procedures such as left atrial myxoma resection and aortic sinus
rupture repair. Table 2 contains the proportions of different cardiac
procedures performed at the time of TV repair.
Data collection and selection criteria
All the patients who underwent TR repair in our center from Feb 2012 to
March 2019 were collected and using the hospital admission numbers, we
searched carefully for all in-hospital and outpatient follow-up
echocardiographic reports. The patients who did not have preoperative
and postoperative follow-up echoes from our hospital were excluded from
this study, and 1005 patients met the selection criteria, therefore
constitute the study population of the present research. Patients who
had TV replacement were equally not included in this study. Overall
heart function was evaluated solely with an echocardiogram done in our
center. The Hospital Ethics Committee approved the retrospective review
of medical records in accordance with the protection of patient
confidentiality, and consented the use of the data for publication;
patients were not identified and individual consent was not obtained.
Surgical Procedure
All the surgeries were performed with the patients under general
anesthesia and tracheal intubation. The sternotomy was performed with a
sternal saw. Cardiopulmonary bypass (CPB) was established routinely:
Bicaval cannulation, moderate systemic hypothermia, local ice-cooling
(for longer CPB time cases), and cardioplegia for myocardial arrest.
The patients who received suture annuloplasty techniques (Kay 62(6.2%)
and classical or modified De Vega 421(41.9%)) were designated Suture
group, and those who underwent ring annuloplasty (522(51.9%)) were
designated Ring group.
Follow-up
There were three postoperative periods in the follow-up of this study:
immediate postoperative (within one-month); one-year and two-year after
the operation. Echocardiographic parameters (TR grade and right atrial
diameter) for each patient preoperatively and at all follow-up time
points were saved on the data bank for analysis.
Statistical Analysis
IBM SPSS Statistics version 21.0 was used for statistical analysis. The
non-normally distributed data were analyzed using the Mann-Whitney U
test and Wilcoxon rank-sum test. Radit analysis was performed to study
data variations within the groups. Normally distributed data were
analyzed using student’s t-test to compare and study the
relationships of continuous variables between the groups. Categorical
variables were presented as counts and percentages. The differences in
categorical variables between patient groups were evaluated with the
Chi-square test or Fisher exact test as appropriate. A p-value
< 0.05 was considered to be significant.
Results
In a universe of 1005 patients who underwent concomitant TV repair, 483
(48.1%) received suture annuloplasty (Suture group) and 522 (51.9%)
received ring annuloplasty (Ring group). The student’s t-test was used
to analyze the patients’ demographics. The mean age at the time of
surgery was 47.9 ±15.0 years (Ring group (50.6±12.7 years); Suture group
(45.0±16.7)) and was significantly different between the groups
(p<0.05 ). The study population was made of 376 (Ring
group n=201 (53.5%), Suture Group n=175 (46.5%)) men and 629 (Ring
group n=321 (51.0%), Suture Group n=308 (49.0%)) women. Gender was not
statistically different between the groups (p>0.05 ).
TR grades were scored as none/trace (1), mild (2), moderate (3), and
severe (4). The patients’ preoperative baseline characteristics are
shown in table 1.
Radit analysis was performed for data variation within the groups. TR
status in all the postoperative three time points of follow-up differed
significantly with preoperative TR status within the Suture group. Among
the 483 patients in the Suture group, 6 (1.2%) presented with
none/trace TR, 189 (39.1%) had mild TR, 220 (45.5%) had moderate TR
and 68 (14.1%) had severe TR, preoperatively. One-month after the
surgery results showed 382 (79.1%) none/trace, 97 (20.1%) mild, 4
(0.8%) moderate and there was no severe TR among the subjects. The two
time points (preoperative and postoperative One-month) TR grades were
significantly different (p<0.05 ) (compare figures 1 and
2).
At one-year time point, there were 366 (75.2%) patients with none/trace
TR, 108 (22.2%) mild, 11 (2.2%) moderate and 1 (0.2%) patient with
severe TR. Although one-year time point TR status was significantly
different from preoperative TR status (p<0.05 ), it did
not differ significantly from the postoperative one-month period
(p>0.05 ). Compare figure 3 with figures 1 and 2.
At two-year follow-up, the number of none/trace TR subjects was 309
(63.9%), 146 (30.1%) mild, 21 (4.4%) moderate, and 7 (1.4%) severe,
showing a statistically significant difference not only to preoperative
TR (p<0.05 ) but also to the postoperative periods of
one-month (p<0.05 ) and one-year
(p<0.05 ). Compare figure 4 with figures 1, 2, and 3.
The changes within the Ring group in the study four time periods were
quite similar to the Suture group. Preoperative TR grades for the 522
patients in the Ring group were as follows: 1 (0.1%) none/trace, 96
(18.3%) mild, 250 (47.8%) moderate and 175 (33.5%) severe; At
one-month follow-up, there were 378 (72.2%) none/trace, 128 (24.5%)
mild, 12 (2.2%) moderate and 4 (0.8%) severe TR. Postoperative
one-month and preoperative TR statuses within the Ring group were
significantly different with a p<0.05 .
At one-year time point, 370 (70.8%) patients had none/trace TR, 138
(26.3%) mild, 13 (2.5%) moderate and 1 (0.2%) patient with severe TR.
These values differed significantly with preoperative TR status
(p<0.05 ), but were similar with postoperative One-month
time period (p>0.05 ). At two-year time point, TR
grades distribution were: 334 (63.9%) none/trace, 156 (29.9%) mild, 28
(5.4%) moderate and 4 (0.6%) severe. This was significantly different
with preoperative TR (p<0.05 ), One-month
(p<0.05 ) and One-year (p<0.05 ).
postoperative one-month.
Right Atrium diameter was another parameter analyzed in this study.
Within the suture group, preoperative mean RA diameter was 39.6±9.4 mm;
after TV repair mean RA diameter was 34.3±6.9 mm, 32.6±7.6 mm, and
27.0±10.9 mm, one-month, one-year, and two-year, respectively. There was
a significant statistical difference of each time point with the other
three time points (p<0.05 ). In the same way, within the
Ring group, preoperative mean RA diameter was 42.5±10.5 mm; after TV
repair, mean RA diameter was 37.3±8.0 mm, 34.3±8.6 mm and 27.8±11.7 mm,
one-month, one-year, and two-year, respectively; and each study time
point significantly differed with the other three time points
(p<0.05 ). Table 4 has the mean RA diameters for each
group at the different time points with T and p values.
Data variation between the groups was analyzed using the Mann-Whitney U
test and Wilcoxon rank-sum test. Preoperative TR grades were distributed
as follows: in the Suture group (n=483), 6 (1.2%) patients had
none/trace TR; 189 (39.1%) mild; 220 (45.5%) moderate; and 68 (14.1%)
severe; in the Ring group (n=522), there was 1 (0.1%) patient with
none/trace TR; 96 (18.3%) mild; 250 (47.8%) moderate; and 175 (33.5%)
severe. There was a statistically significant difference in TR grades
between the two groups preoperatively (p<0.05 ).
One-month after the procedure, echocardiographic follow-up showed 382
(79.1%) of the patients had none/trace TR, 97 (20.1%) mild, 4 (0.8%)
moderate, and there was no severe TR in the Suture group; whereas, 378
(72.2%) patients had none/trace TR, 128 (24.5%) mild, 12 (2.2%)
moderate, and 4 (0.8%) severe TR in the Ring group. TR severity was
significantly different in both groups at one-month follow-up, with ap<0.05 .
One-year follow-up TR grade distribution in the Suture group was: 363
(75.2%) none/trace, 108 (22.2%) mild, 11 (2.2%) moderate, and 1
(0.2%) severe; in the Ring group there were 370 (70.8%) none/trace,
138 (26.3%) mild, 13 (2.5%) moderate, 1 (0.2%) severe TR patient.
There were similar TR grades in the two groups
(p>0.05 ).
At two-year follow up, Suture group experienced the following changes:
309 (63.9%) none/trace, 146 (30.1%) mild, 21 (4.4%) moderate and 7
(1.4%) severe; and Ring group had 334 (63.9%) none/trace, 156 (29.9%)
mild, 28 (5.4%) moderate and 4 (0.6%) severe TR. Equally, there was no
significant difference between the two groups in this follow-up period
(p>0.05 ). Table 3 and figures 1, 2, 3, and 4
illustrate TR changes across the study four time periods between the two
groups.
Right Atrium diameter analysis between the groups showed a preoperative
mean RA diameter of 39.6±9.4 mm in the Suture group, and 42.5±10.5 mm in
the Ring group. The two groups’ preoperative RA diameter was
significantly different (p<0.05 ). At One-month
follow-up, RA diameter significantly differed between the two groups
(Suture group 34.3±6.9 mm; Ring group 37.3±8.0 mm;p<0.05 ); the same results were seen at one-year
follow-up, Suture group 32.6±7.6 mm; Ring group 34.3±8.6 mm
(p<0.05 ). However, at two-year, there were no
statistical difference between the Suture group (27.0±10.9 mm) and Ring
group (27.8±11.7 mm) regarding right atrial diameter
(p>0.05 ).
Discussion
Data have shown that about 20% of patients having cardiac surgery have
significant TR. American and European guidelines agree that severe TR
should be treated in patients undergoing left-sided cardiac
surgery.2 Concomitant surgical intervention is also
recommended for moderate TR with annular dilation of ≥4 cm and history
of RV failure.10 There is an old debate among experts
about the optimal time for surgery and the kind of TV intervention.
Should repair be favored over replacement? Is ring annuloplasty better
than suture annuloplasty?
Despite the gaps in the guidelines and lack of a global consensus, some
habits have been established over the years. Valve repair is typically
preferred to avoid the risks of long-term anti-coagulation, valve
thrombosis, or bio-prosthetic valve degeneration.11 In
addition, a repair can be accomplished rapidly during concomitant
left-sided valve surgery. However, for primary TR, repair mainly depends
on the degree of valve damage; replacement may show better results over
repair in TR cases with severe valve lesions.12 For
functional TR, there is currently a clear tendency favoring valve
repair. Although Marquis-Gravel et al. demonstrated a higher occurrence
of persistent severe TR after TV repair (13%) compared with TV
replacement (2.%);13 preference for repair over
replacement is obvious, particularly when there is a high possibility
that a good post-operative native valve function can be
achieved.14
The ultimate goal of any TR repair technique is to restore leaflet
coaptation. Severe TR frequently presents with annular dilation, and
recent studies15 suggest that ring annuloplasty be
considered in such patients. Navia et al8 did a
retrospective analysis of 2277 patients who underwent TV surgery; they
found a lower rate of recurrent TR with a ring annuloplasty compared
with De Vega annuloplasty. On the other hand, the higher rate of annular
dehiscence after the implantation of a rigid ring was reported in a
study by Pfannmueller and colleagues.6
In the present study, we compared the results of echocardiographic
evaluation between the patients that underwent suture annuloplasty and
those that underwent ring annuloplasty.
TR status at different time points within the study groups showed
statistically significant differences.
In the Suture group, for example, the proportion of none/trace TR
changed from 1.2% preoperative to 79.1%, 75.2%, 63.9% postoperative,
one-month, one-year, and two-year time periods, respectively; the same
group had 14.1% preoperative severe TR that postoperatively changed to
0.0%, 0.2% and 1.4% in one-month, one-year and two-year respectively.
With exception of one-year follow-up compared to one-month follow-up
(p>0.05 ), each follow-up time point is significantly
different from the previous time points (p<0.05 ).
On the other hand, the proportion of none/trace TR in the Ring group
changed from 0.1% preoperatively to 72.2%, 70.8%, 63.9%, one-month,
one-year, and two-year time period, respectively; the same group had
33.5% preoperative severe TR that changed postoperatively to 0.8%,
0.2% and 0.6% at one-month, one-year and two-year, respectively.
Similarly, except for one-year compared to one-month follow-up
(p>0.05 ), each time point was significantly
different from the previous time points (p<0.05 ). The
suture group showed greater change towards worse TR grades over time
compared to the Ring group (table 3).
Right Atrium diameter measurements in the four time points followed
similar changes with TR severity.
Within the Suture group, mean RA diameter progressively became smaller
at all follow-up time points, and each time point was statistically
different from the previous ones (p<0.05 ). The same
pattern was observed within the Ring group. RA diameter at any time
point was statistically different from each of the previous time points
(p<0.05 ).
Data analysis between the groups showed a statistically significant
difference in the preoperative TR grades. The Ring group was
significantly worse than the Suture group TR status(p<0.05). 40.3% of patients in the suture group had
only trace or mild TR, whereas in the Ring group this accounts for
18.4%. Severe TR was 14.0% of all the Suture group, in contrast, it
accounts for 33.5% in the Ring group. Besides, RA diameter (table 4)
equally showed statistical differences between the two groups
(p<0.05 ). This can be explained by the fact that,
generally, more severe cases of TR receive ring annuloplasty. These
patients normally present with pulmonary hypertension, severe annular
dilation, and right heart remodeling. Being a retrospective study, this
research could not manipulate preoperative variables or interfere with
patient selection criteria.
There is also a difference in age between the two groups(p<0.05), and this is because ring annuloplasty is
mostly performed in older patients whereas suture annuloplasty is mostly
reserved for younger ones. There is no difference observed concerning
gender distribution between the groups (p>0.05).
At One-month follow-up, both groups’ TR status improved significantly.
79.1% of the patients in the Suture group presented with none/trace TR,
in the Ring group 72.2% showed none/trace TR. The severe TR cases at
this time point are below 1.0% in each group (0.0% for the Suture
group and 0.8% for the Ring group). The two groups significantly
differed One-month postoperative (p<0.05), with the
Suture group having better outcomes. We believe this difference is the
result of better preoperative conditions in the Suture group (less
severe TR grades and younger age). The two groups equally experienced a
reduction in the RA diameter, which is significantly better than
preoperative condition (p<0.05 ).
At one-year after the surgery, 75.2% of the patients in the Suture
group presented with none/trace TR, in the Ring group 70.8% showed
none/trace TR. Severe TR was 0.2% in the Suture group and 0.2% in the
Ring group. TR status showed no statistically significant difference
between the groups (p>0.05). Despite the Suture
group having a better outcome at one-month, the outcome at one-year was
similar for both groups, showing a progressive deterioration of the
suture techniques as time passes. But concerning RA diameter, further
reduction was seen in the two groups.
Just like at one-year, two-year follow-up TR status showed no
statistically significant difference between the groups
(p>0.05 ). At this time point, none/trace TR
proportion is equal in both groups (63.9%). Severe TR was 1.4% and
0.6% in the Suture group and Ring group, respectively. At the two-year
follow-up, RA diameter equally did not differ between the groups
(p>0.05 ).
The improvement of TR status, after surgical repair, was accompanied by
a reduction in RA diameter in both groups at the three follow-up time
points. One-month and one-year mean RA diameters were all significantly
different in the two groups (p<0.05 ). However, at
two-year, the mean RA diameter was similar in the two groups. This
confirmed the idea that Suture group TR status deteriorated faster than
the Ring group, causing previously different mean RA diameters to become
similar at two years follow-up. These findings coincided with the
variation of TR grades at two years follow-up. Many studies have
reported similar findings in regards to the outcome and durability of
suture annuloplasty.16 17
We believe that ring annuloplasty had better outcomes at two-year
follow-up, in part, because prosthetic rings could better restrict
annular dilation, keep its diameter relatively constant, and slowdown
the progress of TR. Moreover, modern rings have a 3D shape, which tries
to replicate native TA geometrical structure. This enables it to fit in
the annulus in a constant systolic position, restore its physiologic
shape, prevent annular deformation, and warrant a harmonized functioning
of the prosthetic and native TA.18 This cannot be
achieved with suture annuloplasty. Besides, the classical De Vega
technique has the disadvantage of suture detachment19from the tissue, thus failing to promote proper leaflet coaptation and
prevent future annular dilation.
Conclusion
Both annuloplasty techniques have good short-term outcomes, resulting in
the improvement of TR status accompanied by a reduction of the RA
diameters. However, long-term durability with suture annuloplasty is not
as good as ring annuloplasty. Our study finds greater and faster
deterioration of TR grades among the patients in the Suture group over
time. Whereas the deterioration in the Ring group is slower and stable
across three time periods of follow-up, therefore we suggest the use of
ring annuloplasty for TV repair.
Limitations
The findings of the present study may be limited by the fact that our
conclusions are derived exclusively from the analysis of
echocardiographic parameters, and also because of the relatively short
follow-up time (2 years). Future studies, in which combined ultrasound
and clinical data are analyzed, and with longer follow-up periods, can,
in a better way, redeem the limitations of the present study.