The main goals of reconstructive surgery are
the restoration of normal leaflet motion with a
large surface of coaptation and stabilization of the
annulus with remodeling annuloplasty.[
7,
8] Although
various annuloplasty rings are available on the
market, there is still lack of data on absolute assets
of ring functions.[
7,
9] Flexible rings tend to preserve
the contractile performance of LV; Yokote et al.[
10]
demonstrated that transverse diameter is more affected
and did not restrain the annular mobility. Flexible rings
can only be used for degenerative MV diseases. Rigid,
downsizing rings have been associated with reduced risk
of long-term recurrent MR in patients with ischemic or
functional MR.[
11,
12] Despite these findings, it remains
a matter of surgeon’s preference. To tailor the selection
of the annuloplasty ring, our patients were divided
into subgroups according to the MV pathology and
early and midterm changes in echocardiography and
clinical status were evaluated. In Groups 1 and 2, rates
of successful repair were acceptable (72% vs. 88.5%),
the rate of immediate reoperation within 30 days
was 0.3%, and the 30-day mortality rate was fair (9.2% vs. 10.4%) according to the period. Compared
to a decade ago, it is usual to observe improvement
in results with using pre-and perioperative TEE for
anatomical details of the valve and the increasing
experience of institutions. The majority of patients
in our series showed notable improvement of their
MR and symptom severity. To assess the effect of
ring types on clinical outcomes, Khamooshian et
al.[
13] studied degenerative and ischemic MR patients
by dividing them into three groups as rigid, flexible,
and semi-rigid. They concluded that LVESD reduced
with all rings, LVEDD only reduced with rigid and
flexible, and LVEF did not alter. Similarly, our results
projected that LVEF remained unchanged regardless
of ring type. Additionally, the decrease of MR, LA
size, and LVEDD was higher in Group 2 than in
Group 1 in ischemic (MR, p=0.049; LA, p=0.030;
LVEDD, p=0.029) and degenerative (MR, p=0.001;
LA, p=0.005; LVEDD, p=0.014) subgroups (Table
5).
The decrease in the degenerative subgroup was more
significant compared to the ischemic subgroup due to
the delay in remodeling in the presence of ischemic
preconditioning. Although the decrease in MR was
significant with rigid rings in the rheumatic subgroup
(p=0.023), there was no nominal difference in LA
size (p=0.184), LVEDD (p=0.488), and EF (p=0.777)
among rings (Table
5). Given the fact that there was
slightly more reduction with rigid rings, an overall
reduction in the degree of MR was observed with
both rings in all MR pathologies. Additionally, we
have shown that the incidence observed for recurrent
MR in the rigid ring group was significantly lower
compared to the flexible ring group (28% vs. 11.5%,
p<0.01). We believe that ring design might be one
of the provocative reasons, especially in the presence
of ischemic changes. Jensen et al.[
14] concluded that
saddle-shaped rings reduce strain on leaflets by
uniform annular force distribution compared to flat
rings. In our study, perioperative regurgitation up to
Grade 2 with a gradient >5 mmHg was considered
negligible. Recurrent MR was found to be the most
common reason for reoperation.
Table 5: Evaluation of pre- and postoperative changes in echocardiographic parameters according to ring types
In univariate analysis in our results, preoperative
LVEDD, LVESD, LVEF, MR, ring type, ring
number, and concomitant procedures were assessed
for predictors of recurrency, and LVEDD (p=0.001),
LVESD (p=0.001), and ring type (p=0.002) were
found to be statistically significant. Cases having
severe preoperative MR showed 3.065-fold higher
risk of recurrency (odds ratio: 3.605, 95% confidence interval: 0.902-10.409). In multivariate analysis, only
preoperative MR (p=0.038) and LVEDD (p=0.001)
became significant predictors for recurrent MR.
Silberman et al.[12] searched for similar predictors
in the univariate analysis, and preoperative LVESD
and ring type were the predictors of late MR.
There was no statistically significant difference
between ring types on behalf of recurrence-free
(p=0.086) and reoperation-free (p=0.422) survival.
The main goal is to overcome the valvular pathology
while improving the quality of life with preserved
functional capacity. Arnaz et al.[15] reported a
significant improvement in quality of life, and repair
was found to be superior to replacement in terms of
pain score. In our study, a significant improvement
in NYHA was observed in both groups regardless of
ring type at a follow-up period of 15.8±7.5 months
(p=0.001).
There are limitations to this study. Due to its
retrospective nature, data for particular fields, such
as echocardiography records, may have been missing.
Hence, the analyses could have been performed with
available values. More detailed information should be
added for better insight.
In conclusion, a saddle-shaped ring may expand
the mechanical benefits rather than a flat ring by
preserving the native mitral annular shape. Our
study showed uniform results with both types of
rings, improving NYHA class, reducing MR, and
decreasing LV dimensions in patients undergoing
MV repair. Routine intraoperative TEE should be
performed to assess the success of repair for a better
late outcome.
Ethics Committee Approval: The study protocol was
approved by the Kartal Koşuyolu High Specialization Training
and Research Hospital Clinical Research Ethics Committee
(date: 27.03.2013, no: 2013/1.10). The study was conducted in
accordance with the principles of the Declaration of Helsinki.
Patient Consent for Publication: A written informed
consent was obtained from each patient.
Data Sharing Statement: The data that support the
findings of this study are available from the corresponding
author upon reasonable request.
Author Contributions: Concept, design, data collection
and analysis, writing and review: Ö.A.; Supervision, materials
and analysis: S.S.; Concept and critical review: K.K.
Conflict of Interest: The authors declared no conflicts
of interest with respect to the authorship and/or publication
of this article.
Funding: The authors received no financial support for
the research and/or authorship of this article.
){kind=link}
){kind=link}
){kind=link}
){kind=link}
){kind=link}
){kind=link}
){kind=link}