Large annuloplasty rings facilitate mitral valve repair in Barlow's disease.

Abstract

Excess leaflet tissue in Barlow's disease predisposes patients to left ventricular outflow tract obstruction and residual mitral regurgitation after mitral valve repair as a result of systolic anterior motion of the anterior mitral leaflet. In addition to conventional repair techniques such as sliding plasty and leaflet shortening, our approach in Barlow's disease has included the use of large remodeling annuloplasty rings (up to size 40 mm). We report our experience with the use of large rings in Barlow's disease.
From January 2002 to December 2005, 67 patients with Barlow's disease (46 men and 21 women; median age, 55 years; range, 22 to 85 years), mean ejection fraction 0.55 +/- 0.08, and grade 3+ or greater mitral regurgitation underwent mitral valve repair. All had Carpentier type II leaflet dysfunction, with anterior (n = 2), posterior (n = 41), or bileaflet (n = 24) prolapse. Predominant reconstructive techniques were posterior leaflet sliding plasty/plication (n = 65), anterior leaflet triangular resection (n = 16), and chordal transfer (n = 25). Concomitant procedures included coronary artery bypass grafting surgery (n = 8), tricuspid valve repair (n = 20), aortic valve replacement (n = 3), and CryoMaze (n = 22).
Mitral valve repair was successfully completed in all patients. Annuloplasty ring size was 36 mm (n = 17), 38 mm (n = 22), and 40 mm (n = 28). Predischarge transthoracic echocardiography showed absence of systolic anterior motion (n = 67), no or trace mitral regurgitation (n = 62), and mild mitral regurgitation (n = 5). There was no operative mortality.
Mitral valve repair can be predictably performed in Barlow's disease with excellent early outcomes. Large annuloplasty rings help minimize the risk of systolic anterior motion and are an important adjunct to established repair techniques in this patient cohort with large annular size and excess leaflet tissue.

Full text

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Large Annuloplasty Rings Facilitate Mitral Valve
Repair in Barlow’s Disease
David H. Adams, MD, Ani C. Anyanwu, MD, Parwis B. Rahmanian, MD,
Vivian Abascal, MD, Sacha P. Salzberg, MD, and Farzan Filsoufi, MD
Department of Cardiothoracic Surgery, Mount Sinai Medical Center, New York, New York
Background. Excess leaflet tissue in Barlow’s disease
predisposes patients to left ventricular outflow tract
obstruction and residual mitral regurgitation after mi-
tral valve repair as a result of systolic anterior motion
of the anterior mitral leaflet. In addition to conven-
tional repair techniques such as sliding plasty and
leaflet shortening, our approach in Barlow’s disease
has included the use of large remodeling annuloplasty
rings (up to size 40 mm). We report our experience with
the use of large rings in Barlow’s disease.
Methods. From January 2002 to December 2005, 67
patients with Barlow’s disease (46 men and 21 women;
median age, 55 years; range, 22 to 85 years), mean
ejection fraction 0.55 ? 0.08, and grade 3? or greater
mitral regurgitation underwent mitral valve repair. All
had Carpentier type II leaflet dysfunction, with ante-
rior (n ? 2), posterior (n ? 41), or bileaflet (n ? 24)
prolapse. Predominant reconstructive techniques were
posterior leaflet sliding plasty/plication (n ? 65), ante-
rior leaflet triangular resection (n ? 16), and chordal
transfer (n ? 25). Concomitant procedures included
coronary artery bypass grafting surgery (n ? 8), tricus-
pid valve repair (n ? 20), aortic valve replacement (n ?
3), and CryoMaze (n ? 22).
Results. Mitral valve repair was successfully com-
pleted in all patients. Annuloplasty ring size was 36
mm (n ? 17), 38 mm (n ? 22), and 40 mm (n ? 28).
Predischarge transthoracic echocardiography showed
absence of systolic anterior motion (n ? 67), no or trace
mitral regurgitation (n ? 62), and mild mitral regurgi-
tation (n ? 5). There was no operative mortality.
Conclusions. Mitral valve repair can be predictably
performed in Barlow’s disease with excellent early
outcomes. Large annuloplasty rings help minimize the
risk of systolic anterior motion and are an important
adjunct to established repair techniques in this patient
cohort with large annular size and excess leaflet tissue.
(Ann Thorac Surg 2006;82:2096–101)
© 2006 by The Society of Thoracic Surgeons
B
degeneration with excessive leaflet tissue. Barlow’s
disease is a cause of MR, usually secondary to leaflet
prolapse (Carpentier’s type II dysfunction). The pri-
mary lesion causing prolapse is chordal elongation or
rupture, and secondary lesions include annular dilata-
tion, chordal thickening, papillary muscle calcification,
and annular calcification. Although the “billowing pos-
terior mitral valve syndrome” was first recognized as a
cause of systolic murmurs in the 1960s by Barlow and
Pocock [1], the surgical characterization of what is now
known as Barlow’s disease was largely undertaken in
the 1970s by Carpentier and associates [2]. Excess
leaflet tissue, the hallmark of Barlow’s disease, poses a
specific challenge during mitral valve repair because it
predisposes to the development of systolic anterior
motion (SAM) of the mitral valve. Systolic anterior
arlow’s disease is a common cause of mitral regur-
gitation (MR) and is characterized by myxoid
motion in this context occurs by means of two principal
mechanisms—either the residual posterior leaflet is
left too tall such that it displaces the anterior leaflet
into the left ventricular outflow tract; or the annulo-
plasty ring is smaller than the surface area of the
anterior leaflet, potentially forcing excess tissue into
the outflow tract [3]. The former is dealt with effectively
by Carpentier’s sliding-plasty technique [4]. The latter
requires that the annuloplasty ring is true-sized to the
anterior leaflet, or that alternative procedures are un-
dertaken to address excess anterior leaflet height [5].
Most Barlow valves are large, and if rings are being
true-sized then one should expect a preponderance of
large rings (36 mm or greater) in repair series that
include Barlow valves. There are, however, little con-
firmatory data in the literature on the use of such large
annuloplasty rings. Indeed many institutions do not
stock these large ring sizes, and some annuloplasty
rings are not manufactured in sizes above 36 mm. In
this paper we present our recent experience with
Accepted for publication June 9, 2006.
Presented at the Forty-second Annual Meeting of The Society of Thoracic
Surgeons, Chicago, IL, Jan 30–Feb 1, 2006.
Address correspondence to Dr Adams, Department of Cardiothoracic
Surgery, Mount Sinai Medical Center, 1190 Fifth Ave, New York, NY
10029-1028; e-mail: david.adams@mountsinai.org.
Dr Adams discloses that he has a financial relationship
with Edwards Lifesciences.
© 2006 by The Society of Thoracic Surgeons
Published by Elsevier Inc
0003-4975/06/$32.00
doi:10.1016/j.athoracsur.2006.06.043
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mitral valve repair using large annuloplasty rings
(between size 36 and 40 mm) in patients with Barlow’s
disease.
Material and Methods
Patients
All patients undergoing mitral valve surgery at our
institution are entered into a prospective database. Insti-
tutional Review Board approval with a waiver of individ-
ual consent was obtained for this study. We retrospec-
tively identified patients who underwent mitral valve
surgery between January 2002 and December 2005 and
had a surgical diagnosis of Barlow’s disease. To be
included in this series patients must have had an annu-
loplasty ring of 36 mm or greater and a primary indica-
tion for surgery of MR. Seventy-five patients underwent
mitral valve surgery for Barlow’s disease during the
study period, all of whom underwent successful repair.
There were no valve replacements undertaken for Bar-
low’s disease during the study period. Eight patients had
a forme fruste of the disease with excess, thickened tissue
but a valve size smaller than 36 mm and were excluded
from this study, leaving 67 consecutive Barlow patients
who had mitral valve repair using annuloplasty rings of
36 mm or greater. These 67 patients form the cohort for
this analysis. Table 1 summarizes the preoperative char-
acteristics. Twenty patients (30%) had 3? MR (moderate
to severe) whereas 47 patients (70%) had 4? MR (severe).
Definitions
Barlow’s disease was defined according to the lines of
Carpentier and associates [2, 6, 7]. Usually patients with
Barlow’s disease have a long history (several years) of a
murmur and do not have any alternative causative fac-
tors (such as Marfan’s disease or endocarditis). On in-
spection of the valve, we used the following characteris-
tics to define a valve as Barlow’s (Fig 1A):
Billowing valve with excess tissue and thickened leaflets
Chords typically thickened and elongated
Large valve with severe annular dilatation
Chordal rupture, annular calcification, and papillary
muscle calcification may be present.
Surgical Techniques
All procedures were performed by a single surgeon
(D.H.A). Repairs were performed through a full sternot-
omy (N ? 54, 80%) or minimally invasive approach (N ?
13, 20%). Our minimally invasive approach was an 8- to
10-cm lower midline incision and lower hemi-
sternotomy. Operations were performed using mild hy-
pothermic cardiopulmonary bypass with antegrade and
retrograde warm and cold blood cardioplegia and topical
hypothermia used for myocardial protection. All valves
were accessed through a left atriotomy in the interatrial
groove. During valve analysis, lesions producing valve
dysfunction(s) were identified as were the leaflet and
annular dimensions. Valve repairs were performed ac-
cording to the principles of Carpentier [4, 6, 8]. Our
specific approach was to sequentially repair the posterior
leaflet by resecting any prolapsing segment, reduce the
posterior annular dimension, reconstruct the posterior
leaflet, perform a true-sized annuloplasty using a com-
plete semirigid remodeling ring, and then repair any
residual prolapse of the anterior leaflet or commissures
Table 1. Patient Demographics
CharacteristicsN (%)
Male gender
Median age (y)
Hypertension
Diabetes
Mean EF
NYHA class
I
II
III
IV
MR grade
3?
4?
Atrial fibrillation
Reoperation
46 (69)
55 (range 22–85)
8 (12)
3 (4)
0.55 ? 0.08
12 (18)
35 (52)
20 (30)
0 (0)
20 (30)
47 (70)
22 (33)
2 (3)
EF ? ejection fraction;
York Heart Association.
MR ? mitral regurgitation; NYHA ? New
Fig 1. (A) Barlow’s valve with excess thickened leaflet tissue and billowing of both leaflets. (B) Barlow valve repair after posterior leaflet slid-
ing plasty and size 40-mm Physio-Ring annuloplasty.
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after inspecting the line of closure during saline testing.
In the setting of excess posterior leaflet tissue, we per-
formed a leaflet resection and a sliding leaflet-plasty to
reduce the height of the posterior leaflet to 1 to 1.5 cm in
all segments. Before leaflet plasty, we reduced the pos-
terior annular circumference by placing horizontal plica-
tion sutures to relieve excess tension on the margin of the
posterior leaflet. We corrected anterior leaflet prolapse
primarily by chordal transfer and triangular resection. A
Carpentier-Edwards (C-E) Physio Annuloplasty Ring,
(Edwards LifeSciences, Irvine, CA) was used in all pa-
tients (Fig 1B) [8]. The ring size chosen was based on the
true size of the anterior mitral leaflet. This was deter-
mined by using standard C-E mitral sizers to measure
both the intercommissural distance and the anterior-
posterior leaflet dimension, with a bias to choose the
larger size if between sizes (Fig 2). Adjunctive procedures
performed included tricuspid valve repair (n ? 20; 30%),
coronary artery bypass grafting surgery (n ? 8; 12%),
closure of patent foramen ovale (n ? 8; 12%), aortic valve
replacement (n ? 3; 5%), and a modified maze procedure
(n ? 22, 33%). Intraoperative transesophageal echocardi-
ography was performed in each patient after weaning
from cardiopulmonary bypass to detect left ventricular
outflow tract obstruction owing to SAM and any residual
MR.
Echocardiography
Before hospital discharge, two-dimensional and Doppler
transthoracic echocardiography examination was per-
formed in all patients using a 3.5-MHz transducer and
commercially available echocardiographic systems. The
presence of MR was assessed, and its severity was
evaluated semiquantitatively using the regurgitant color
jet area [9]. Regurgitation was classified as none (when
no MR is present), trace (regurgitation that is barely
detected), mild (jet area ? 4 cm2), moderate (jet area ? 4
and ? 10 cm2) and severe (jet area ? 10 cm2). All
echocardiograms were retrospectively assessed in a core
laboratory by a cardiologist (V.A.) blinded to the clinical
outcome and to the initial interpretation of the
echocardiogram.
Data Acquisition
At the time of mitral surgery, all valves were analyzed,
and specific lesions and prolapsing segments were doc-
umented. All repair techniques were subsequently doc-
umented. These data were entered prospectively into a
mitral valve database. Clinical outcome data were re-
corded prospectively in a general cardiac surgery data-
base. Morbidity was defined according to guidelines of
the New York State Department of Health [10]. Addi-
tional information was obtained by retrospective chart
review as required.
Results
Valve Analysis
All patients had Carpentier type II dysfunction. Forty-
one (61%) patients had isolated posterior leaflet prolapse,
24 (36%) bileaflet prolapse, and 2 (3%) isolated anterior
leaflet prolapse. Segmental analysis revealed that when
the posterior leaflet was involved, multiple segments
were involved in 37 cases (57%), and when the anterior
leaflet was involved, multiple segments were involved in
14 cases (54%). The P2 and A2 segments were the most
Fig 3. Segmental analysis of valve prolapse. Numbers in middle of
large circles depict isolated prolapse of the labeled segment. Over-
lapping areas depict prolapse involving more than one segment.
Fig 2. Correct leaflet sizing technique (A) and demonstration of a
size 40-mm valve (B).
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commonly involved. Segmental analysis results are
shown in Figure 3. The lesions present were annular
dilatation, 67 (100%); chordal elongation, 57 (85%);
chordal rupture, 26 (39%); annular calcification, 8 (12%);
and papillary muscle calcification, 5 (7%).
Surgical Procedures
All patients underwent successful mitral valve repair
documented by intraoperative transesophageal echo-
cardiography. One patient in the series had SAM
identified in the operating room. This patient had
received a size 38 mm ring and had sliding plasty of the
P2 and P3 segments. On the second time during
cardiopulmonary bypass the P1 segment was short-
ened with complete resolution of SAM and no residual
MR. The median cardiopulmonary bypass time was 199
minutes (interquartile range, 170 to 260 minutes) and
cross-clamp time 168 minutes (interquartile range, 135
to 225 minutes). The valve repair techniques used are
shown in Table 2.
Mortality and Morbidity
There was no in-hospital or 30-day mortality. Postoper-
ative complications included respiratory failure requiring
prolonged ventilation in 2 patients (3%), bleeding requir-
ing reoperation in 1 patient (1%), and renal failure in 1
patient (1%). In addition, one deep sternal infection
occurred (1%).
Echocardiographic Results
Predischarge transthoracic MR grade is shown in Table 3.
Sixty-two patients (93%) had no or trace MR, whereas 5
patients (7%) had mild MR. There was no evidence of
SAM in any patient. No significant change in mean
ejection fraction was demonstrated.
Comment
Using Carpentier’s techniques, with an emphasis on
removing excess posterior leaflet tissue and respecting
excess anterior leaflet tissue by the use of true-sized
large annuloplasty rings (36 mm or greater), we have
shown that Barlow valves can be repaired with excel-
lent early echocardiographic results including absence
of significant residual MR and minimal risk of SAM. A
review of the literature does not yield any similar
series of large annuloplasty rings. Most published
series on mitral valve repair for degenerative disease
do not differentiate between Barlow and non-Barlow
causes or do not give information on annuloplasty ring
size. Thus it is difficult to know the true incidence of
usage of large rings in patients with Barlow’s disease.
Given the paucity of data on this subject and the lack of
large sizes (?36 mm) of some manufactured annulo-
plasty rings, we believe that the use of such large rings
may be relatively infrequent. Most Barlow valves are,
however, quite large and have excess tissue by defini-
tion. Given the distribution of ring size in our study
with a mode of 40 mm, we would expect (assuming a
natural distribution) that there are Barlow valves that
are size 42 and 44 mm. Indeed we encountered two
anterior leaflets with a true size greater that 40 mm
(currently the largest manufactured ring size), which
required shortening.
The use of true-sized large rings was integral to our
approach to avoid SAM and residual MR after mitral
valve repair for Barlow’s disease. Some workers have
advocated reducing the anterior leaflet height [5],
performing an edge-to-edge repair [11], using incom-
plete flexible bands in preference to complete annulo-
plasty rings [12, 13], or even avoiding annuloplasty
rings altogether [14] as a means of reducing the inci-
dence of SAM. Routine resection of the anterior leaflet
changes the geometric relationship between the ante-
rior leaflet height and the intercommissural distance,
which forms the basis for the concept of remodeling
annuloplasty; we prefer to respect this relationship,
except in the unusual circumstance of a giant anterior
leaflet (?40 mm). Although the edge-to-edge tech-
nique has been reported as a means of preventing
SAM, the long-term durability of this technique in
degenerative mitral valve repair is unknown. Systolic
anterior motion has been described both with the use
of flexible posterior bands [15] and even without the
use of annuloplasty rings [16, 17], such that ring choice
or use alone is not the key to avoiding SAM.
A possible explanation for the paucity of data on
large rings is that a significant proportion of patients
with large Barlow valves may be undergoing mitral
valve replacement rather than repair, as these large
Barlow valves are among the most complex valves to
repair and are also those at greatest risk of SAM.
Table 3. Predischarge Echocardiographic Mitral
Regurgitation Grade
Graden (%)
None or trace
Mild
Moderate
Severe
62 (93%)
5 (7%)
0 (0%)
0 (0%)
Table 2. Surgical Procedures
ProcedureN (%)
Annuloplasty ring size (mm)
36
38
40
Repair techniques
Posterior leaflet resection
Anterior leaflet resection
Posterior leaflet sliding plasty
Chordal transfer
Anterior leaflet shortening
Gore-Tex chordoplasty
Papillary muscle shortening
17 (25)
22 (33)
28 (42)
65 (97)
16 (24)
56 (84)
25 (37)
2 (4)
2 (3)
2 (3)
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Although much is written on its prevention, SAM
remains a concern in contemporary degenerative mi-
tral valve repair [15], and such concerns about com-
plexity of repair and SAM likely remain a limiting
factor in the uptake of mitral valve repair [18]. We
believe large remodeling rings have played a role in
our ability to achieve a 100% repair rate for Barlow’s
disease without postoperative SAM or significant re-
sidual MR.
Strengths and Limitations
A unique strength of our study lies in the prospective
documentationofvalveanalysisandrepairprocedures,and
our uniform application of surgical technique [19]. All valve
classifications were done at the time of surgery and not
based on retrospective chart review. Likewise, we did not
rely on echocardiographic reports for postoperative MR
grading, but had the studies re-reviewed in a systematic
core manner. Our series is one of the most comprehensive
surgical documentations of Barlow’s disease in contempo-
rary literature. We were necessarily limited by the absence
of a control group, ie, we do not know what our experience
would have been without the use of large true-sized rings.
We were unable to identify any suitable historic, concur-
rent, or literature controls. Most published series do not
define specific cause of degenerative disease and also do
not document ring size, preventing useful comparison. As
ourseriesisrelativelyrecent,andourstudyobjectivewasto
examine early outcomes (SAM and residual MR), we do not
have any mid-term outcomes data. The absence of residual
MR (no patients in our series had more than mild residual
MR) is, however, encouraging as this is a strong predictor of
excellent long-term durability after mitral valve repair [20,
21].
Conclusions
Although we advocate repair for all degenerative valves
[22], we acknowledge that Barlow mitral valve repairs using
Carpentier’s techniques are technically sophisticated and
lengthy procedures. In our experience, more than 25% of
repairs require cardiopulmonary bypass times in excess of
4 hours, and a majority of cases included prolapse of
multiple leaflet segments that required correction. How-
ever, as we achieved a 100% success rate (no significant
residual MR), with minimal morbidity and no mortality, we
believe such complicated mitral valve repairs are worth-
while and are preferable to valve replacement.
As mitral valve repair extends to completely asymptom-
atic patients (18% in our series), we must aim to guarantee
a successful repair in every circumstance, regardless of
cause, valve size, and valve lesions; we found the use of
true-sized large remodeling annuloplasty rings a useful
adjunct to achieving this goal in our series.
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